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Sample records for acetaldehyde

  1. Acetaldehyde and gastric cancer.

    Science.gov (United States)

    Salaspuro, Mikko

    2011-04-01

    Aldehyde dehydrogenase (ALDH2) and alcohol dehydrogenase (ADH) gene polymorphisms associating with enhanced acetaldehyde exposure and markedly increased cancer risk in alcohol drinkers provide undisputable evidence for acetaldehyde being a local carcinogen not only in esophageal but also in gastric cancer. Accordingly, acetaldehyde associated with alcoholic beverages has recently been classified as a Group 1 carcinogen to humans. Microbes are responsible for the bulk of acetaldehyde production from ethanol both in saliva and Helicobacter pylori-infected and achlorhydric stomach. Acetaldehyde is the most abundant carcinogen in tobacco smoke and it readily dissolves into saliva during smoking. Many foodstuffs and 'non-alcoholic' beverages are important but unrecognized sources of local acetaldehyde exposure. The cumulative cancer risk associated with increasing acetaldehyde exposure suggests the need for worldwide screening of the acetaldehyde levels of alcoholic beverages and as well of the ethanol and acetaldehyde of food produced by fermentation. The generally regarded as safe status of acetaldehyde should be re-evaluated. The as low as reasonably achievable principle should be applied to the acetaldehyde of alcoholic and non-alcoholic beverages and food. Risk groups with ADH-and ALDH2 gene polymorphisms, H. pylori infection or achlorhydric atrophic gastritis, or both, should be screened and educated in this health issue. L-cysteine formulations binding carcinogenic acetaldehyde locally in the stomach provide new means for intervention studies. PMID:21401890

  2. Acetaldehyde in the Alaskan subarctic snow pack

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    F. Domine

    2009-09-01

    Full Text Available Acetaldehyde is a reactive intermediate in hydrocarbon oxidation. It is both emitted and taken up by snowpacks and photochemical and physical processes are probably involved. Understanding the reactivity of acetaldehyde in snow and its processes of physical and chemical exchanges requires the knowledge of its incorporation mechanism in snow crystals. We have performed a season-long study of the evolution of acetaldehyde concentrations in the subarctic snowpack near Fairbanks (65° N, central Alaska, which is subjected to a vigorous metamorphism due to persistent elevated temperature gradients in the snowpack, between 20 and 200°C m−1. The snowpack therefore almost entirely transforms into depth hoar. We have also analyzed acetaldehyde in a manipulated snowpack where temperature gradients were suppressed. Snow crystals there transformed much more slowly and their original shapes remained recognizable for months. The specific surface area of snow layers in both types of snowpacks was also measured. We deduce that acetaldehyde is not adsorbed onto the surface of snow crystals and that most of the acetaldehyde is probably not dissolved in the ice lattice of the snow crystals. We propose that most of the acetaldehyde measured is either trapped or dissolved within organic aerosol particles trapped in snow, or that acetaldehyde is formed by the hydrolysis of organic precursors contained in organic aerosols trapped in the snow, when the snow is melted for analysis. These precursors are probably aldehyde polymers formed within the aerosol particles by acid catalysis, but might also be biological molecules. In a laboratory experiment, acetaldehyde-di-n-hexyl acetal, representing a potential acetaldehyde precursor, was subjected to our analytical procedure and reacted to form acetaldehyde. This confirms our suggestion that acetaldehyde in snow could be produced during the melting of snow for analysis.

  3. Acetaldehyde Adducts in Alcoholic Liver Disease

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    Mashiko Setshedi

    2010-01-01

    Full Text Available Chronic alcohol abuse causes liver disease that progresses from simple steatosis through stages of steatohepatitis, fibrosis, cirrhosis, and eventually hepatic failure. In addition, chronic alcoholic liver disease (ALD, with or without cirrhosis, increases risk for hepatocellular carcinoma (HCC. Acetaldehyde, a major toxic metabolite, is one of the principal culprits mediating fibrogenic and mutagenic effects of alcohol in the liver. Mechanistically, acetaldehyde promotes adduct formation, leading to functional impairments of key proteins, including enzymes, as well as DNA damage, which promotes mutagenesis. Why certain individuals who heavily abuse alcohol, develop HCC (7.2–15% versus cirrhosis (15–20% is not known, but genetics and co-existing viral infection are considered pathogenic factors. Moreover, adverse effects of acetaldehyde on the cardiovascular and hematologic systems leading to ischemia, heart failure, and coagulation disorders, can exacerbate hepatic injury and increase risk for liver failure. Herein, we review the role of acetaldehyde adducts in the pathogenesis of chronic ALD and HCC.

  4. Study on development of adsorbent of acetaldehyde; Acetaldehyde yo kyuchakuzai no kaihatsu ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Noda, T. [Nippon Steel Corp., Tokyo (Japan); Suzuki, M. [The University of Tokyo, Tokyo (Japan). Institute of Industrial Science

    1997-07-10

    The adsorption of acetaldehyde by porous ceramics impregnated with hydrazinium aluminum sulfate (HAS) is studied. Silicagel, activated alumina, activated clay, and activated carbon are compared, and it is found that silicagel and activated clay are suitable as a substrate for HAS impregnated adsorbent. The adsorption mechanism of acetaldehyde by the adsorbent is believed to be one in which acetaldehyde reacts with hydrazinium and yields acetaldazine. The adsorption capacity of the adsorbent at low acetaldehyde concentration of 0.1 ppm was as large as 1.36 mol/kg. This adsorption capacity at 0.1 ppm acetaldehyde concentration is remarkably larger than that of conventional activated carbon. Hydrazinium decomposes easily in the air because it is a strong reducing agent and reacts with oxygen or carbon dioxide. But hydrazinium impregnated on porous ceramics with HAS becomes more stable and maintains reactivity with acetaldehyde for longer than six months. An adsorbent made of porous ceramics impregnated with HAS is useful as a deodorant for acetaldehyde. 8 refs., 6 figs., 6 tabs.

  5. Ethylene oxide and Acetaldehyde in hot cores

    CERN Document Server

    Occhiogrosso, A; Herbst, E; Viti, S; Ward, M D; Price, S D; Brown, W A

    2014-01-01

    [Abridged] Ethylene oxide and its isomer acetaldehyde are important complex organic molecules because of their potential role in the formation of amino acids. Despite the fact that acetaldehyde is ubiquitous in the interstellar medium, ethylene oxide has not yet been detected in cold sources. We aim to understand the chemistry of the formation and loss of ethylene oxide in hot and cold interstellar objects (i) by including in a revised gas-grain network some recent experimental results on grain surfaces and (ii) by comparison with the chemical behaviour of its isomer, acetaldehyde. We test the code for the case of a hot core. The model allows us to predict the gaseous and solid ethylene oxide abundances during a cooling-down phase prior to star formation and during the subsequent warm-up phase. We can therefore predict at what temperatures ethylene oxide forms on grain surfaces and at what temperature it starts to desorb into the gas phase. The model reproduces the observed gaseous abundances of ethylene oxid...

  6. Prebiotic synthesis of imidazole-4-acetaldehyde and histidine

    Science.gov (United States)

    Shen, Chun; Oro, J.; Yang, Lily; Miller, Stanley L.

    1987-01-01

    The prebiotic synthesis of imidazole-4-acetaldehyde and imidazole-4-glycol from erythrose and formamidine has been demonstrated as well as the prebiotic synthesis of imidazole-4-ethanol and imidazole-4-glycol from erythrose, formaldehyde, and ammonia. The maximum yields of imidazole-4-acetaldehyde, imidazole-4-ethanol, and imidazole-4-glycol obtained in these reactions are 1.6, 5.4, and 6.8 percent respectively, based on the erythrose. Imidazole-4-acetaldehyde would have been converted to histidine on the primitive earth by a Strecker synthesis, and several prebiotic reactions would convert imidazole-4-glycol and imidazole-4-ethanol to imidazole-4-acetaldehyde.

  7. Widespread acetaldehyde near the Galactic Centre

    CERN Document Server

    Chengalur, J N; Chengalur, Jayaram N.; Kanekar, Nissim

    2003-01-01

    We present Giant Meterwave Radio Telescope images of the 1065 MHz emission from the 1_11 -> 1_10 rotational transition of acetaldehyde (CH3CHO) in the molecular cloud complex Sgr B2. Our observations are unique in that they have a high spatial resolution (~4"), while still being sensitive to large-scale emission. Most complex organic molecules in this cloud (e.g. acetone, methyl formate, acetic acid) are concentrated in a very small core, ~0.1pc across. In contrast, acetaldehyde is found to be spread over a region at least 100 times larger in extent. The line emission is confined to regions with radio continuum emission and correlates well (in both position and velocity) with formaldehyde absorption towards this continuum; this is consistent with earlier single dish results suggesting that it is likely to be weakly mased. Our observations also suggest that grain mantle destruction by shocks plays an important role in the observed gas phase abundance of CH3CHO in Sgr B2.

  8. 40 CFR 721.10036 - Acetaldehyde based polymer (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Acetaldehyde based polymer (generic... Specific Chemical Substances § 721.10036 Acetaldehyde based polymer (generic). (a) Chemical substance and... based polymer (PMN P-02-406) is subject to reporting under this section for the significant new...

  9. Mechanism of acetaldehyde-induced deactivation of microbial lipases

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    Jaeger Karl E

    2011-02-01

    Full Text Available Abstract Background Microbial lipases represent the most important class of biocatalysts used for a wealth of applications in organic synthesis. An often applied reaction is the lipase-catalyzed transesterification of vinyl esters and alcohols resulting in the formation of acetaldehyde which is known to deactivate microbial lipases, presumably by structural changes caused by initial Schiff-base formation at solvent accessible lysine residues. Previous studies showed that several lipases were sensitive toward acetaldehyde deactivation whereas others were insensitive; however, a general explanation of the acetaldehyde-induced inactivation mechanism is missing. Results Based on five microbial lipases from Candida rugosa, Rhizopus oryzae, Pseudomonas fluorescens and Bacillus subtilis we demonstrate that the protonation state of lysine ε-amino groups is decisive for their sensitivity toward acetaldehyde. Analysis of the diverse modification products of Bacillus subtilis lipases in the presence of acetaldehyde revealed several stable products such as α,β-unsaturated polyenals, which result from base and/or amino acid catalyzed aldol condensation of acetaldehyde. Our studies indicate that these products induce the formation of stable Michael-adducts at solvent-accessible amino acids and thus lead to enzyme deactivation. Further, our results indicate Schiff-base formation with acetaldehyde to be involved in crosslinking of lipase molecules. Conclusions Differences in stability observed with various commercially available microbial lipases most probably result from different purification procedures carried out by the respective manufacturers. We observed that the pH of the buffer used prior to lyophilization of the enzyme sample is of utmost importance. The mechanism of acetaldehyde-induced deactivation of microbial lipases involves the generation of α,β-unsaturated polyenals from acetaldehyde which subsequently form stable Michael-adducts with the

  10. Complex oscillations in the combustion of acetaldehyde

    Science.gov (United States)

    Harding, Robert H.; Sevčikova, Hana; Ross, John

    1988-10-01

    Aperiodic dynamics are observed experimentally in the cool flame combustion region of acetaldehyde (ACH) in a continuous stirred tank reactor (CSTR). A gradual transition is seen, with variation of exit orifice size, from limit cycle oscillation to aperiodic variations in light emission, and then back to near periodic oscillations. We analyze this transition by calculating power spectra, autocorrelation functions, phase portraits, period distributions, and Poincaré sections. The variation in peak amplitude and peak-to-peak period of the temporal variations of light emission increases during the transition. There are many initial indications of a transition to chaos. However, after an in-depth analysis, given in the following article, we ascribe the transition to the presence of a Hopf bifurcation and noise: the path traced out in the constraint space by the change in exit orifice size is nearly tangent to a Hopf bifurcation set but does not cross this set.

  11. In vitro inhibition of 10-formyltetrahydrofolate dehydrogenase activity by acetaldehyde

    OpenAIRE

    Mun, Ju-Ae; Doh, Eunjin; Min, Hyesun

    2008-01-01

    Alcoholism has been associated with folate deficiency in humans and laboratory animals. Previous study showed that ethanol feeding reduces the dehydrogenase and hydrolase activity of 10-formyltetrahydrofolate dehydrogenase (FDH) in rat liver. Hepatic ethanol metabolism generates acetaldehyde and acetate. The mechanisms by which ethanol and its metabolites produce toxicity within the liver cells are unknown. We purified FDH from rat liver and investigated the effect of ethanol, acetaldehyde an...

  12. Atmospheric Vinyl Alcohol to Acetaldehyde Tautomerization Revisited.

    Science.gov (United States)

    Peeters, Jozef; Nguyen, Vinh Son; Müller, Jean-François

    2015-10-15

    The atmospheric oxidation of vinyl alcohol (VA) produced by photoisomerization of acetaldehyde (AA) is thought to be a source of formic acid (FA). Nevertheless, a recent theoretical study predicted a high rate coefficient k1(298 K) of ≈10(-14) cm(3) molecule(-1) s(-1) for the FA-catalyzed tautomerization reaction 1 of VA back into AA, which suggests that FA buffers its own production from VA. However, the unusually high frequency factor implied by that study prompted us to reinvestigate reaction 1 . On the basis of a high-level ab initio potential energy profile, we first established that transition state theory is applicable, and derived a k1(298 K) of only ≈2 × 10(-20) cm(3) molecule(-1) s(-1), concluding that the reaction is negligible. Instead, we propose and rationalize another important VA sink: its uptake by aqueous aerosol and cloud droplets followed by fast liquid-phase tautomerization to AA; global modeling puts the average lifetime by this sink at a few hours, similar to oxidation by OH. PMID:26722769

  13. Decarboxylation of Pyruvate to Acetaldehyde for Ethanol Production by Hyperthermophiles

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    Mohammad S. Eram

    2013-08-01

    Full Text Available Pyruvate decarboxylase (PDC encoded by pdc is a thiamine pyrophosphate (TPP-containing enzyme responsible for the conversion of pyruvate to acetaldehyde in many mesophilic organisms. However, no pdc/PDC homolog has yet been found in fully sequenced genomes and proteomes of hyper/thermophiles. The only PDC activity reported in hyperthermophiles was a bifunctional, TPP- and CoA-dependent pyruvate ferredoxin oxidoreductase (POR/PDC enzyme from the hyperthermophilic archaeon Pyrococcus furiosus. Another enzyme known to be involved in catalysis of acetaldehyde production from pyruvate is CoA-acetylating acetaldehyde dehydrogenase (AcDH encoded by mhpF and adhE. Pyruvate is oxidized into acetyl-CoA by either POR or pyruvate formate lyase (PFL, and AcDH catalyzes the reduction of acetyl-CoA to acetaldehyde in mesophilic organisms. AcDH is present in some mesophilic (such as clostridia and thermophilic bacteria (e.g., Geobacillus and Thermoanaerobacter. However, no AcDH gene or protein homologs could be found in the released genomes and proteomes of hyperthermophiles. Moreover, no such activity was detectable from the cell-free extracts of different hyperthermophiles under different assay conditions. In conclusion, no commonly-known PDCs was found in hyperthermophiles. Instead of the commonly-known PDC, it appears that at least one multifunctional enzyme is responsible for catalyzing the non-oxidative decarboxylation of pyruvate to acetaldehyde in hyperthermophiles.

  14. Relationship between acetaldehyde concentration in mouth air and tongue coating volume

    OpenAIRE

    YOKOI, Aya; Maruyama, Takayuki; Yamanaka, Reiko; Ekuni, Daisuke; Tomofuji, Takaaki; Kashiwazaki, Haruhiko; Yamazaki, Yutaka; Morita, Manabu

    2015-01-01

    Objective Acetaldehyde is the first metabolite of ethanol and is produced in the epithelium by mucosal ALDH, while higher levels are derived from microbial oxidation of ethanol by oral microflora such as Candida species. However, it is uncertain whether acetaldehyde concentration in human breath is related to oral condition or local production of acetaldehyde by oral microflora. The aim of this pilot study was to investigate the relationship between physiological acetaldehyde concentration an...

  15. [A gas chromatographic method for determining acetaldehyde in cadaver blood].

    Science.gov (United States)

    Savich, V I; Valladares, Kh A; Gusakov, Iu A; Skachko, Z M

    1990-01-01

    Gas-chromatographic method of acetaldehyde detection in blood of subjects who died of alcoholic intoxication is suggested. Method is simple, does not require additional expenses, can be readily used in medicolegal practice and in difficult cases it may help the expert to make an objective conclusion on the cause of death. PMID:2087747

  16. Formaldehyde and acetaldehyde emissions from residential wood combustion in Portugal

    Science.gov (United States)

    Cerqueira, Mário; Gomes, Luís; Tarelho, Luís; Pio, Casimiro

    2013-06-01

    A series of experiments were conducted to characterize formaldehyde and acetaldehyde emissions from residential combustion of common wood species growing in Portugal. Five types of wood were investigated: maritime pine (Pinus pinaster), eucalyptus (Eucalyptus globulus), cork oak (Quercus suber), holm oak (Quercus rotundifolia) and pyrenean oak (Quercus pyrenaica). Laboratory experiments were performed with a typical wood stove used for domestic heating in Portugal and operating under realistic home conditions. Aldehydes were sampled from diluted combustion flue gas using silica cartridges coated with 2,4-dinitrophenylhydrazine and analyzed by high performance liquid chromatography with diode array detection. The average formaldehyde to acetaldehyde concentration ratio (molar basis) in the stove flue gas was in the range of 2.1-2.9. Among the tested wood types, pyrenean oak produced the highest emissions for both formaldehyde and acetaldehyde: 1772 ± 649 and 1110 ± 454 mg kg-1 biomass burned (dry basis), respectively. By contrast, maritime pine produced the lowest emissions: 653 ± 151 and 371 ± 162 mg kg-1 biomass (dry basis) burned, respectively. Aldehydes were sampled separately during distinct periods of the holm oak wood combustion cycles. Significant variations in the flue gas concentrations were found, with higher values measured during the devolatilization stage than in the flaming and smoldering stages.

  17. Relationship between acetaldehyde concentration in mouth air and tongue coating volume

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    Aya YOKOI

    2015-02-01

    Full Text Available Objective Acetaldehyde is the first metabolite of ethanol and is produced in the epithelium by mucosal ALDH, while higher levels are derived from microbial oxidation of ethanol by oral microflora such as Candida species. However, it is uncertain whether acetaldehyde concentration in human breath is related to oral condition or local production of acetaldehyde by oral microflora. The aim of this pilot study was to investigate the relationship between physiological acetaldehyde concentration and oral condition in healthy volunteers. Material and Methods Sixty-five volunteers (51 males and 14 females, aged from 20 to 87 years old participated in the present study. Acetaldehyde concentration in mouth air was measured using a portable monitor. Oral examination, detection of oral Candida species and assessment of alcohol sensitivity were performed. Results Acetaldehyde concentration [median (25%, 75%] in mouth air was 170.7 (73.5, 306.3 ppb. Acetaldehyde concentration in participants with a tongue coating status score of 3 was significantly higher than in those with a score of 1 (p<0.017. After removing tongue coating, acetaldehyde concentration decreased significantly (p<0.05. Acetaldehyde concentration was not correlated with other clinical parameters, presence of Candida species, smoking status or alcohol sensitivity. Conclusion Physiological acetaldehyde concentration in mouth air was associated with tongue coating volume.

  18. Plant physiological and environmental controls over the exchange of acetaldehyde between forest canopies and the atmosphere

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    K. Jardine

    2008-06-01

    Full Text Available We quantified fine scale sources and sinks of gas phase acetaldehyde in two forested ecosystems in the US. During the daytime, the upper canopy behaved as a net source while at lower heights, reduced emission rates or net uptake were observed. At night, uptake generally predominated thoughout the canopies. Net ecosystem emission rates were inversely related to foliar density which influenced the extinction of light and the acetaldehyde compensation point in the canopy. This is supported by branch level studies revealing much higher compensation points in the light than in the dark for poplar (Populus deltoides and holly oak (Quercus ilex implying a higher light/temperature sensitivity for acetaldehyde production relative to consumption. The view of stomata as the major pathway for acetaldehyde exchange is supported by strong linear correlations between branch transpiration rates and acetaldehyde exchange velocities for both species. In addition, natural abundance carbon isotope analysis of gas-phase acetaldehyde during poplar branch fumigation experiments revealed a significant kinetic isotope effect of 5.1±0.3‰, associated with the uptake of acetaldehyde. Similar experiments with dry dead poplar leaves showed no fractionation or uptake of acetaldehyde, confirming that this is only a property of living leaves. We suggest that acetaldehyde belongs to a potentially large list of plant metabolites where stomatal conductance can exert long term control over both emission and uptake rates due to the presence of both source(s and sink(s within the leaf which strongly buffer large changes in concentrations in the substomatal airspace due to changes in stomatal conductance. We conclude that the exchange of acetaldehyde between plant canopies and the atmosphere is fundamentally controlled by ambient acetaldehyde concentrations, stomatal conductance, and the acetaldehyde compensation point.

  19. Quantum Chemical Study on Reaction of Acetaldehyde with Hydroxyl Radical

    Institute of Scientific and Technical Information of China (English)

    LI,Ming(李明); ZHANG,Jin-Sheng(张金生); SHEN,Wei(申伟); MENG,Qing-Xi(孟庆喜)

    2004-01-01

    The reaction of acetaldehyde with hydroxyl radical was studied by means of quantum chemical methods. The geometries for all the stationary points on the potential energy surfaces were optimized fully, respectively, at the G3MP2, G3, and MP2/6-311++G(d,p) levels. Single-point energies of all the species were calculated at the QCISD/6-311 + +G(d,p) level. The mechanism of the reaction studied was confirmed. The predicted product is acetyl radical that is in agreement with the experiment.

  20. Plant physiological and environmental controls over the exchange of acetaldehyde between forest canopies and the atmosphere

    Directory of Open Access Journals (Sweden)

    K. Jardine

    2008-11-01

    Full Text Available We quantified fine scale sources and sinks of gas phase acetaldehyde in two forested ecosystems in the US. During the daytime, the upper canopy behaved as a net source while at lower heights, reduced emission rates or net uptake were observed. At night, uptake generally predominated throughout the canopies. Net ecosystem emission rates were inversely related to foliar density due to the extinction of light in the canopy and a respective decrease of the acetaldehyde compensation point. This is supported by branch level studies revealing much higher compensation points in the light than in the dark for poplar (Populus deltoides and holly oak (Quercus ilex implying a higher light/temperature sensitivity for acetaldehyde production relative to consumption. The view of stomata as the major pathway for acetaldehyde exchange is supported by strong linear correlations between branch transpiration rates and acetaldehyde exchange velocities for both species. In addition, natural abundance carbon isotope analysis of gas-phase acetaldehyde during poplar branch fumigation experiments revealed a significant kinetic isotope effect of 5.1±0.3‰ associated with the uptake of acetaldehyde. Similar experiments with dry dead poplar leaves showed no fractionation or uptake of acetaldehyde, confirming that this is only a property of living leaves. We suggest that acetaldehyde belongs to a potentially large list of plant metabolites where stomatal resistance can exert long term control over both emission and uptake rates due to the presence of both source(s and sink(s within the leaf which strongly buffer large changes in concentrations in the substomatal airspace due to changes in stomatal resistance. We conclude that the exchange of acetaldehyde between plant canopies and the atmosphere is fundamentally controlled by ambient acetaldehyde concentrations, stomatal resistance, and the compensation point which is a function of light/temperature.

  1. 40 CFR 80.56 - Measurement methods for formaldehyde and acetaldehyde.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Measurement methods for formaldehyde... Measurement methods for formaldehyde and acetaldehyde. (a) Formaldehyde and acetaldehyde will be measured by....140 of this chapter for formaldehyde analysis. Diluted exhaust sample volumes must be at least 15...

  2. Oxygen vacancy-assisted coupling and enolization of acetaldehyde on CeO2(111).

    Science.gov (United States)

    Calaza, Florencia C; Xu, Ye; Mullins, David R; Overbury, Steven H

    2012-10-31

    The temperature-dependent adsorption and reaction of acetaldehyde (CH(3)CHO) on a fully oxidized and a highly reduced thin-film CeO(2)(111) surface have been investigated using a combination of reflection-absorption infrared spectroscopy (RAIRS) and periodic density functional theory (DFT+U) calculations. On the fully oxidized surface, acetaldehyde adsorbs weakly through its carbonyl O interacting with a lattice Ce(4+) cation in the η(1)-O configuration. This state desorbs at 210 K without reaction. On the highly reduced surface, new vibrational signatures appear below 220 K. They are identified by RAIRS and DFT as a dimer state formed from the coupling of the carbonyl O and the acyl C of two acetaldehyde molecules. This dimer state remains up to 400 K before decomposing to produce another distinct set of vibrational signatures, which are identified as the enolate form of acetaldehyde (CH(2)CHO¯). Furthermore, the calculated activation barriers for the coupling of acetaldehyde, the decomposition of the dimer state, and the recombinative desorption of enolate and H as acetaldehyde are in good agreement with previously reported TPD results for acetaldehyde adsorbed on reduced CeO(2)(111) [Chen et al. J. Phys. Chem. C 2011, 115, 3385]. The present findings demonstrate that surface oxygen vacancies alter the reactivity of the CeO(2)(111) surface and play a crucial role in stabilizing and activating acetaldehyde for coupling reactions. PMID:23020248

  3. The hydrogen-storing microporous silica 'Microcluster' reduces acetaldehyde contained in a distilled spirit.

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    Kato, Shinya; Miwa, Nobuhiko

    2016-12-01

    Acetaldehyde is a detrimental substance produced in alcoholic liquor aging. We assessed an ability of hydrogen-storing microporous silica 'Microcluster' (MC+) to reduce acetaldehyde, as compared with autoclave-dehydrogenated MC+ (MC-). Acetaldehyde was quantified spectrophotometrically by an enzymatic method. Authentic acetaldehyde was treated by MC+ for 20min, and decreased from 43.4ppm to 10.9ppm, but maintained at 49.3ppm by MC-. On the other hand, acetaldehyde contained in a distilled spirit was decreased from 29.5ppm to 3.1ppm at 20min by MC+, but not decreased by MC-. Addition of MC+ or MC- to distilled water without acetaldehyde showed no seeming effect on the quantification used. Accordingly acetaldehyde in a distilled spirit is reduced to ethanol by hydrogen contained in MC+, but not by the silica moiety of MC+. Hydrogen gas of 1.2mL was released for 20min from MC+ of 0.59g in water, resulting in dissolved hydrogen of 1.09ppm and an oxidation- reduction potential of -687.0mV indicative of a marked reducing ability. Thus, MC+ has an ability to reduce acetaldehyde in a distilled spirit due to dissolved hydrogen released from MC+. PMID:27612695

  4. Acetaldehyde alters MAP kinase signalling and epigenetic histone modifications in hepatocytes.

    Science.gov (United States)

    Shukla, Shivendra D; Lee, Youn Ju; Park, Pil-hoon; Aroor, Annayya R

    2007-01-01

    Although both oxidative and non-oxidative metabolites of ethanol are involved in generating ethanol matabolic stress (Emess), the oxidative metabolite acetaldehyde plays a critical role in the cellular actions of ethanol. We have investigated the effects of acetaldehyde on p42/44 MAP kinase, p46/p54 c-jun N-terminal kinase (JNK1/JNK2) and p38 MAP kinase in hepatocytes. Acetaldehyde caused temporal activation of p42/44 MAPK followed by JNK, but the activation of the p42/44 MAPK was not a prerequisite for the JNK activation. Activation ofJNK1 by acetaldehyde was greater than JNK2. Ethanol and acetaldehyde activatedJNK have opposing roles; ethanol-induced JNK activation increased apoptosis whereas that by acetaldehyde decreased apoptosis. Acetaldehyde also caused histone H3 acetylation at Lys9 and phosphorylation of histone H3 at Serl0 and 28, the latter being dependent on p38 MAP kinase. Phosphorylation at Ser28 was higher than at Serl0. Thus acetaldehyde distinctively alters MAP kinase signalling and histone modifications, processes involved in transcriptional activation. PMID:17590997

  5. Dissociative electron attachments to ethanol and acetaldehyde: A combined experimental and simulation study

    Science.gov (United States)

    Wang, Xu-Dong; Xuan, Chuan-Jin; Feng, Wen-Ling; Tian, Shan Xi

    2015-02-01

    Dissociation dynamics of the temporary negative ions of ethanol and acetaldehyde formed by the low-energy electron attachments is investigated by using the anion velocity map imaging technique and ab initio molecular dynamics simulations. The momentum images of the dominant fragments O-/OH- and CH3- are recorded, indicating the low kinetic energies of O-/OH- for ethanol while the low and high kinetic energy distributions of O- ions for acetaldehyde. The CH3- image for acetaldehyde also shows the low kinetic energy. With help of the dynamics simulations, the fragmentation processes are qualitatively clarified. A new cascade dissociation pathway to produce the slow O- ion via the dehydrogenated intermediate, CH3CHO- (acetaldehyde anion), is proposed for the dissociative electron attachment to ethanol. After the electron attachment to acetaldehyde molecule, the slow CH3- is produced quickly in the two-body dissociation with the internal energy redistributions in different aspects before bond cleavages.

  6. EFFECT OF SOME TECHNOLOGICAL FACTORS ON THE CONTENT OF ACETALDEHYDE IN BEER

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    Gunka Jonkova

    2010-10-01

    Full Text Available The purpose of this work was to examine the influence of the temperature, the pitching rate of yeast and wort composition (Free Amino Nitrogen on the content of acetaldehyde in beer. It is known, that higher fermentation temperatures stimulate the formation of acetaldehyde, as well as the higher rate of acetaldehyde reduction, leading to lower concentrations in the final beer. Beer produced with increased pitching rate of yeast (26 and 35 × 10[sup]6[/sup] cells•mL[sup]-1[/sup], contains lower quantities of acetaldehyde as compared to the control beer. Lower content of α-amino nitrogen in result of substitution of 5 to 10�0of the malt with rice, sugar or a combination of both does not lead to considerable differences in the acetaldehyde concentration in beer.

  7. [Effect of pyruvate, threonine, and phosphoethanolamine on acetaldehyde metabolism in rats with toxic liver injury].

    Science.gov (United States)

    Pron'ko, P S; Satanovskaia, V I; Gorenshteĭn, B I; Kuz'mich, A B; Pyzhik, T N

    2002-01-01

    Pyruvate dehydrogenase, threonine aldolase and phosphoethanolamine lyase can produce acetaldehyde during normal metabolism. We studied the effect of loading with the substrates of these enzymes (pyruvate, 500 mg/kg, i.p., threonine 500 mg/kg, i.p., and phosphoethanolamine, 230 mg/kg, i.p.) on the blood concentrations of endogenous acetaldehyde and ethanol and the activities of enzymes producing and oxidizing acetaldehyde in the liver of normal rats and rats with liver injury provoked by chronic carbon tetrachloride (CCl4) treatment (0.2 ml i.p. per rat, 2 times a week during 4 weeks). Blood was collected before the treatment and then 30 min and 1 h following the administration of the substrates to intact and CCl4-treated rats. Endogenous acetaldehyde and ethanol were determined by headspace GC. The CCl4 treatment resulted in decreased liver alcohol dehydrogenase and aldehyde dehydrogenase activities and a significant elevation of liver endogenous ehtanol and a clear tendency to enhance blood acetaldehyde levels. Pyruvate increased blood endogenous acetaldehyde in CCl4-treated animals and endogenous ethanol--in the control group of animals. Threonine elevated endogenous acetaldehyde in normal rats. Phosphoethanolamine increased endogenous ethanol in the intact and CCl4 groups. At the same time, in CCl4-treated rats pyruvate administration increased the liver pyruvate dehydrogenase, threonine decreased threonine aldolase, whereas phosphoethanolamine decreased phosphoethanolamine lyase. Thus, the CCl4 effect on blood endogenous acetaldehyde and ethanol may be mediated through decreased liver ALDH and ADH activities. Liver injury promotes the accumulation of acetaldehyde, derived from physiological sources, including the degration of pyruvate and threonine by decreased acetaldehyde oxidation.

  8. Acetaldehyde stimulation of net gluconeogenic carbon movement from applied malic acid in tomato fruit pericarp tissue

    Energy Technology Data Exchange (ETDEWEB)

    Halinska, A.; Frenkel, C. (Rutgers, The State Univ. of New Jersey, New Brunswick (United States))

    1991-03-01

    Applied acetaldehyde is known to lead to sugar accumulation in fruit including tomatoes (Lycopersicon esculentum) presumably due to stimulation of gluconeogenesis. This conjecture was examined using tomato fruit pericarp discs as a test system and applied l-(U-{sup 14}C)malic acid as the source for gluconeogenic carbon mobilization. Results indicate that malic and perhaps other organic acids are carbon sources for gluconeogenesis occurring normally in ripening tomatoes. The process is stimulated by acetaldehyde apparently by attenuating the fructose-2,6-biphosphate levels. The mode of the acetaldehyde regulation of fructose-2,6-biphosphate metabolism awaits clarification.

  9. EFFECT OF SOME TECHNOLOGICAL FACTORS ON THE CONTENT OF ACETALDEHYDE IN BEER

    OpenAIRE

    Gunka Jonkova; Nevjana Petkova

    2010-01-01

    The purpose of this work was to examine the influence of the temperature, the pitching rate of yeast and wort composition (Free Amino Nitrogen) on the content of acetaldehyde in beer. It is known, that higher fermentation temperatures stimulate the formation of acetaldehyde, as well as the higher rate of acetaldehyde reduction, leading to lower concentrations in the final beer. Beer produced with increased pitching rate of yeast (26 and 35 × 10[sup]6[/sup] cells•mL[sup]-1[/sup]), contains low...

  10. Pervaporation of Aqueous Solution of Acetaldehyde Through ZSM-5 Filled PDMS Composite Membrane

    Institute of Scientific and Technical Information of China (English)

    伍艳辉; 谭惠芬; 李佟茗; 金源

    2012-01-01

    Hydrophobic ZSM-5 zeolite filled polydimethylsiloxane (PDMS) composite membranes with Nylon micro-filtration membrane as the support layer were prepared to separate acetaldehyde from its aqueous solution. The composite membranes were characterized by Fourier transform infrared spectroscopy and X-ray diffraction. Their structural morphology and thermal stability were also examined. The swelling study showed that the composite membranes presented higher degree of swelling in aqueous solution of acetaldehyde than in pure water at 25℃,

  11. One-pot microbial synthesis of 2'-deoxyribonucleoside from glucose, acetaldehyde, and a nucleobase.

    Science.gov (United States)

    Horinouchi, Nobuyuki; Ogawa, Jun; Kawano, Takako; Sakai, Takafumi; Saito, Kyota; Matsumoto, Seiichiro; Sasaki, Mie; Mikami, Yoichi; Shimizu, Sakayu

    2006-06-01

    A one-pot enzymatic synthesis of 2'-deoxyribonucleoside from glucose, acetaldehyde, and a nucleobase was established. Glycolysis by baker's yeast (Saccharomyces cerevisiae) generated ATP which was used to produce D: -glyceraldehyde 3-phosphate production from glucose via fructose 1,6-diphosphate. The D: -glyceraldehyde 3-phosphate produced was transformed to 2'-deoxyribonucleoside via 2-deoxyribose 5-phosphate and then 2-deoxyribose 1-phosphate in the presence of acetaldehyde and a nucleobase by deoxyriboaldolase, phosphopentomutase expressed in Escherichia coli, and a commercial nucleoside phosphorylase. About 33 mM 2'-deoxyinosine was produced from 600 mM glucose, 333 mM acetaldehyde and 100 mM adenine in 24 h. 2'-Deoxyinosine was produced from adenine due to the adenosine deaminase activity of E. coli transformants.

  12. Artisanal alcohol production in Mayan Guatemala: Chemical safety evaluation with special regard to acetaldehyde contamination

    Energy Technology Data Exchange (ETDEWEB)

    Kanteres, Fotis [Centre for Addiction and Mental Health (CAMH), 33 Russell Street, ARF 2035, Toronto, ON, Canada, M5S 2 S1 (Canada); Rehm, Juergen [Centre for Addiction and Mental Health (CAMH), 33 Russell Street, ARF 2035, Toronto, ON, Canada, M5S 2 S1 (Canada); Dalla Lana School of Public Health, University of Toronto, 155 College Street, Toronto, ON, Canada, M5T 3 M7 (Canada); Institute for Clinical Psychology and Psychotherapy, TU Dresden, Chemnitzer Strasse 46, D-01187 Dresden (Germany); Lachenmeier, Dirk W., E-mail: Lachenmeier@web.de [Chemisches und Veterinaeruntersuchungsamt (CVUA) Karlsruhe, Weissenburger Strasse 3, D-76187 Karlsruhe (Germany)

    2009-11-01

    There is a lack of knowledge regarding the composition, production, distribution, and consumption of artisanal alcohol, particularly in the developing world. In Nahuala, an indigenous Mayan municipality located in highland Guatemala, heavy alcohol consumption appears to have had a significant negative impact on health, a major role in cases of violence and domestic abuse, and a link to street habitation. Cuxa, an artisanally, as well as commercially produced sugarcane alcohol, is widely consumed by heavy drinkers in this community. Cuxa samples from all distribution points in the community were obtained and chemically analyzed for health-relevant constituents and contaminants including methanol, acetaldehyde, higher alcohols, and metals. From those, only acetaldehyde was confirmed to be present in unusually high levels (up to 126 g/hl of pure alcohol), particularly in samples that were produced clandestinely. Acetaldehyde has been evaluated as 'possibly carcinogenic' and has also been identified as having significant human exposure in a recent risk assessment. This study explores the reasons for the elevated levels of acetaldehyde, through both sampling and analyses of raw and intermediary products of cuxa production, as well as interviews from producers of the clandestine alcohol. For further insight, we experimentally produced this alcohol in our laboratory, based on the directions provided by the producers, as well as materials from the town itself. Based on these data, the origin of the acetaldehyde contamination appears to be due to chemical changes induced during processing, with the major causative factors consisting of poor hygiene, aerobic working conditions, and inadequate yeast strains, compounded by flawed distillation methodology that neglects separation of the first fractions of the distillate. These results indicate a preventable public health concern for consumers, which can be overcome through education about good manufacturing practices

  13. Artisanal alcohol production in Mayan Guatemala: Chemical safety evaluation with special regard to acetaldehyde contamination

    International Nuclear Information System (INIS)

    There is a lack of knowledge regarding the composition, production, distribution, and consumption of artisanal alcohol, particularly in the developing world. In Nahuala, an indigenous Mayan municipality located in highland Guatemala, heavy alcohol consumption appears to have had a significant negative impact on health, a major role in cases of violence and domestic abuse, and a link to street habitation. Cuxa, an artisanally, as well as commercially produced sugarcane alcohol, is widely consumed by heavy drinkers in this community. Cuxa samples from all distribution points in the community were obtained and chemically analyzed for health-relevant constituents and contaminants including methanol, acetaldehyde, higher alcohols, and metals. From those, only acetaldehyde was confirmed to be present in unusually high levels (up to 126 g/hl of pure alcohol), particularly in samples that were produced clandestinely. Acetaldehyde has been evaluated as 'possibly carcinogenic' and has also been identified as having significant human exposure in a recent risk assessment. This study explores the reasons for the elevated levels of acetaldehyde, through both sampling and analyses of raw and intermediary products of cuxa production, as well as interviews from producers of the clandestine alcohol. For further insight, we experimentally produced this alcohol in our laboratory, based on the directions provided by the producers, as well as materials from the town itself. Based on these data, the origin of the acetaldehyde contamination appears to be due to chemical changes induced during processing, with the major causative factors consisting of poor hygiene, aerobic working conditions, and inadequate yeast strains, compounded by flawed distillation methodology that neglects separation of the first fractions of the distillate. These results indicate a preventable public health concern for consumers, which can be overcome through education about good manufacturing practices, as well

  14. Genetic-epidemiological evidence for the role of acetaldehyde in cancers related to alcohol drinking.

    Science.gov (United States)

    Eriksson, C J Peter

    2015-01-01

    Alcohol drinking increases the risk for a number of cancers. Currently, the highest risk (Group 1) concerns oral cavity, pharynx, larynx, esophagus, liver, colorectum, and female breast, as assessed by the International Agency for Research on Cancer (IARC). Alcohol and other beverage constituents, their metabolic effects, and alcohol-related unhealthy lifestyles have been suggested as etiological factors. The aim of the present survey is to evaluate the carcinogenic role of acetaldehyde in alcohol-related cancers, with special emphasis on the genetic-epidemiological evidence. Acetaldehyde, as a constituent of alcoholic beverages, and microbial and endogenous alcohol oxidation well explain why alcohol-related cancers primarily occur in the digestive tracts and other tissues with active alcohol and acetaldehyde metabolism. Genetic-epidemiological research has brought compelling evidence for the causality of acetaldehyde in alcohol-related cancers. Thus, IARC recently categorized alcohol-drinking-related acetaldehyde to Group 1 for head and neck and esophageal cancers. This is probably just the tip of the iceberg, since more recent epidemiological studies have also shown significant positive associations between the aldehyde dehydrogenase ALDH2 (rs671)*2 allele (encoding inactive enzyme causing high acetaldehyde elevations) and gastric, colorectal, lung, and hepatocellular cancers. However, a number of the current studies lack the appropriate matching or stratification of alcohol drinking in the case-control comparisons, which has led to erroneous interpretations of the data. Future studies should consider these aspects more thoroughly. The polymorphism phenotypes (flushing and nausea) may provide valuable tools for future successful health education in the prevention of alcohol-drinking-related cancers.

  15. ALDH2 genotype has no effect on salivary acetaldehyde without the presence of ethanol in the systemic circulation.

    Directory of Open Access Journals (Sweden)

    Andreas Helminen

    Full Text Available BACKGROUND: Acetaldehyde associated with alcoholic beverages was recently classified as carcinogenic (Group 1 to humans based on uniform epidemiological and biochemical evidence. ALDH2 (aldehyde dehydrogenase 2 deficient alcohol consumers are exposed to high concentrations of salivary acetaldehyde and have an increased risk of upper digestive tract cancer. However, this interaction is not seen among ALDH2 deficient non-drinkers or rare drinkers, regardless of their smoking status or consumption of edibles containing ethanol or acetaldehyde. Therefore, the aim of this study was to examine the effect of the ALDH2 genotype on the exposure to locally formed acetaldehyde via the saliva without ethanol ingestion. METHODS: The ALDH2 genotypes of 17 subjects were determined by PCR-RFLP. The subjects rinsed out their mouths with 5 ml of 40 vol% alcohol for 5 seconds. Salivary ethanol and acetaldehyde levels were measured by gas chromatography. RESULTS: Acetaldehyde reached mutagenic levels rapidly and the exposure continued for up to 20 minutes. The mean salivary acetaldehyde concentrations did not differ between ALDH2 genotypes. CONCLUSIONS: For ALDH2 deficient subjects, an elevated exposure to endogenously formed acetaldehyde requires the presence of ethanol in the systemic circulation. IMPACT: Our findings provide a logical explanation for how there is an increased incidence of upper digestive tract cancers among ALDH2 deficient alcohol drinkers, but not among those ALDH2 deficient subjects who are locally exposed to acetaldehyde without bloodborne ethanol being delivered to the saliva. Thus, ALDH2 deficient alcohol drinkers provide a human model for increased local exposure to acetaldehyde derived from the salivary glands.

  16. Development of industrial brewing yeast with low acetaldehyde production and improved flavor stability.

    Science.gov (United States)

    Wang, Jinjing; Shen, Nan; Yin, Hua; Liu, Chunfeng; Li, Yongxian; Li, Qi

    2013-02-01

    Higher acetaldehyde concentration in beer is one of the main concerns of current beer industry in China. Acetaldehyde is always synthesized during beer brewing by the metabolism of yeast. Here, using ethanol as the sole carbon source and 4-methylpyrazole as the selection marker, we constructed a new mutant strain with lower acetaldehyde production and improved ethanol tolerance via traditional mutagenesis strategy. European Brewery Convention tube fermentation tests comparing the fermentation broths of mutant strain and industrial brewing strain showed that the acetaldehyde concentration of mutant strain was 81.67 % lower, whereas its resistant staling value was 1.0-fold higher. Owing to the mutation, the alcohol dehydrogenase activity of the mutant strain decreased to about 30 % of the wild-type strain. In the meantime, the fermentation performance of the newly screened strain has little difference compared with the wild-type strain, and there are no safety problems regarding the industrial usage of the mutant strain. Therefore, we suggest that the newly screened strain could be directly applied to brewing industry.

  17. Acetaldehyde behavior over platinum based catalyst in hydrogen stream generated by ethanol reforming

    Energy Technology Data Exchange (ETDEWEB)

    de Lima, Adriana F.F. [Laboratorio de Catalise, Instituto Nacional de Tecnologia, Av. Venezuela 82/507, 20081-310 Rio de Janeiro, RJ (Brazil); Instituto de Quimica e INOG (Instituto Nacional de Oleo Gas), UERJ-CNPq, FAPERJ, Universidade do Estado do Rio de Janeiro, Rua Sao Francisco Xavier, 524, 20550-900 Rio de Janeiro, RJ (Brazil); Colman, Rita C. [Departamento de Engenharia Quimica e de Petroleo, Universidade Federal Fluminense, Av. Passos da Patria, 156/bl E/240, 24210-240 Niteroi, RJ (Brazil); Zotin, Fatima M.Z. [Instituto de Quimica e INOG (Instituto Nacional de Oleo Gas), UERJ-CNPq, FAPERJ, Universidade do Estado do Rio de Janeiro, Rua Sao Francisco Xavier, 524, 20550-900 Rio de Janeiro, RJ (Brazil); CETEM-MCT, Av. Pedro Calmon, 900, Cidade Universitaria, 21941-908 Rio de Janeiro, RJ (Brazil); Appel, Lucia G. [Laboratorio de Catalise, Instituto Nacional de Tecnologia, Av. Venezuela 82/507, 20081-310 Rio de Janeiro, RJ (Brazil)

    2010-12-15

    Due to the greenhouse effect, hydrogen production from bioethanol reforming is a very important subject in heterogeneous catalysis research. Pt based catalysts are employed in H{sub 2} purification processes and also as electrocatalysts of PEM (''Proton Exchange Membrane'') fuel cells. Hydrogen obtained from ethanol reforming may contain, as contaminants, acetaldehyde and small amounts of CO. This aldehyde can be decarbonylated on Pt based catalysts generating carbon monoxide and methane, rendering the hydrogen purification more challenging. Moreover, acetaldehyde might also change the electrocatalyst behavior. Therefore, this contribution aims at studying the acetaldehyde behavior in the presence of platinum based catalysts in hydrogen atmosphere. The Pt/SiO{sub 2}, Pt/USY catalysts and an electrocatalyst were characterized by n-butylamine, H{sub 2} and CO{sub 2} adsorption, ATG/DTG measurements and cyclohexane dehydrogenation reaction. It was observed that the acid-basic properties of the supports promote condensation reactions. When in contact with Pt based catalysts, acetaldehyde undergoes C-C and C=O bond scissions. The former occurs at a wide range of temperatures, whereas the latter only at low temperatures (<200 C). The C-C bond scission (decarbonylation) produces methane and CO. The C=O bond scission generates carbon residues on the catalyst as well as oxygen species, which in turn is able to eliminate CO from the catalytic surface. The data also show that decarbonylation is not a structure-sensitive reaction. (author)

  18. [Effect of pyrazole on the activity of acetaldehyde-producing enzymes in the liver].

    Science.gov (United States)

    Gerashchenko, D Iu; Gorenshteĭn, B I; Pyzhik, T N; Ostrovskiĭ, Iu M

    1993-01-01

    Influence of pyrazole on the endogenous ethanol level and activities of acetaldehyde-producing enzymes was investigated. Drastic enhancement of the endogenous ethanol level in the blood and tissues was accompanied by an insignificant increase of phosphoethanolamine lyase activity, while activity of threonine aldolase and pyruvate dehydrogenase was unchanged.

  19. Adsorption of Chromium(VI from Aqueous Solutions by Coffee Polyphenol-Formaldehyde/Acetaldehyde Resins

    Directory of Open Access Journals (Sweden)

    Khudbudin Mulani

    2013-01-01

    Full Text Available Removal of chromium(VI from wastewater is essential as it is toxic. Thus, removal of chromium(VI was performed using coffee polyphenol-formaldehyde/acetaldehyde resins as adsorbents. Adsorbent resins were prepared by condensation of decaffeinated coffee powder with formaldehyde/acetaldehyde and used for the removal of Cr(VI ions from aqueous solutions. A simple and sensitive solid phase extraction procedure was applied for the determination of chromium at trace levels by spectroscopic method using 1,5-diphenylcarbazide reagent. The adsorption of Cr(VI on the coffee polyphenol-formaldehyde/acetaldehyde resins was monitored by FTIR and EDX analysis. The metal adsorption parameters such as contact time, pH, Cr(VI ion concentration, and adsorbent dose were investigated. For Cr(VI, the maximum adsorption capacity of coffee polyphenol-formaldehyde resins was 98% at pH 2. The experimental results showed that Cr(VI bound strongly with coffee polyphenol-formaldehyde/acetaldehyde resins and utilization of resins could be improved greatly by reuse.

  20. Abundances of ethylene oxide and acetaldehyde in hot molecular cloud cores

    Science.gov (United States)

    Nummelin, A.; Dickens, J. E.; Bergman, P.; Hjalmarson, A.; Irvine, W. M.; Ikeda, M.; Ohishi, M.

    1998-01-01

    We have searched for millimetre-wave line emission from ethylene oxide (c-C2H4O) and its structural isomer acetaldehyde (CH3CHO) in 11 molecular clouds using SEST. Ethylene oxide and acetaldehyde were detected through multiple lines in the hot cores NGC 6334F, G327.3-0.6, G31.41+0.31, and G34.3+0.2. Acetaldehyde was also detected towards G10.47+0.03, G322.2+0.6, and Orion 3'N, and one ethylene oxide line was tentatively detected in G10.47+0.03. Column densities and rotational excitation temperatures were derived using a procedure which fits the observed line intensifies by finding the minimum chi 2-value. The resulting rotational excitation temperatures of ethylene oxide and acetaldehyde are in the range 16-38 K, indicating that these species are excited in the outer, cooler parts of the hot cores or that the excitation is significantly subthermal. For an assumed source size of 20", the deduced column densities are (0.6-1)x10(14) cm-2 for ethylene oxide and (2-5)x10(14) cm-2 for acetaldehyde. The fractional abundances with respect to H2 are X[c-C2H4O]=(2-6)xl0(-10), and X[CH3CHO]=(0.8-3)x10(-9). The ratio X[CH3CHO]/X[c-C2H4O] varies between 2.6 (NGC 6334F) and 8.5 (G327.3-0.6). We also detected and analysed multiple transitions of CH3OH, CH3OCH3, C2H5OH, and HCOOH. The chemical, and possibly evolutionary, states of NGC 6334F, G327.3-0.6, G31.41+0.31, and G34.3+0.2 seem to be very similar.

  1. Modeling of experimental treatment of acetaldehyde-laden air and phenol-containing water using corona discharge technique.

    Science.gov (United States)

    Faungnawakij, Kajornsak; Sano, Noriaki; Charinpanitkul, Tawatchai; Tanthapanichakoon, Wiwut

    2006-03-01

    Acetaldehyde-laden air and phenol-contaminated water were experimentally treated using corona discharge reactions and gas absorption in a single water-film column. Mathematical modeling of the combined treatment was developed in this work. Efficient removal of the gaseous acetaldehyde was achieved while the corona discharge reactions produced short-lived species such as O and O- as well as ozone. Direct contact of the radicals and ions with water was known to produce aqueous OH radical, which contributes to the decomposition of organic contaminants: phenol, absorbed acetaldehyde, and intermediate byproducts in the water. The influence of initial phenol concentration ranging from 15 to 50 mg L(-1) and that of influent acetaldehyde ranging from 0 to 200 ppm were experimentally investigated and used to build the math model. The maximum energetic efficiency of TOC, phenol, and acetaldehyde were obtained at 25.6 x 10(-9) mol carbon J(-1), 25.0 x 10(-9) mol phenol J(-1), and 2.0 x 10(-9) mol acetaldehyde J(-1), respectively. The predictions for the decomposition of acetaldehyde, phenol, and their intermediates were found to be in good agreement with the experimental results. PMID:16568779

  2. Formation of 2-propanol in condensed molecular films of acetaldehyde following electron impact ionisation-induced proton transfer*

    Science.gov (United States)

    Borrmann, Tobias; Swiderek, Petra

    2016-06-01

    Experimental studies on thin condensed layers of acetaldehyde have previously revealed that electron exposure at an energy above the ionisation threshold leads to formation of 2-propanol. However, the mechanism of this reaction remained unclear. Therefore, a computational approach is used to explore the electron-induced reactions of acetaldehyde yielding 2-propanol. Starting from hydrogen-bonded dimers of acetaldehyde we show that the initial ionisation event triggers proton transfer between the two acetaldehyde moieties resulting in a hydrogen-bonded complex of a [OCCH3] radical and a protonated acetaldehyde cation. Given an excess energy of up to 0.75 eV and a favourable arrangement, a methyl radical released upon dissociation of the CC bond within the [OCCH3] radical can migrate to the carbonyl carbon of the protonated acetaldehyde cation. This produces a 2-propanol radical cation and CO. Neutral 2-propanol is then obtained by recombination with a second electron. A mechanism involving ionisation-driven proton transfer is thus proposed as pathway to the formation of 2-propanol during electron exposure of condensed layers of acetaldehyde.

  3. Selective catalytic reduction of nitric oxide with acetaldehyde over NaY zeolite catalyst in lean exhaust feed

    International Nuclear Information System (INIS)

    Steady-state selective catalytic reduction (SCR) of nitric oxide (NO) was investigated under simulated lean-burn conditions using acetaldehyde (CH3CHO) as the reductant. This work describes the influence of catalyst space velocity and the impact of nitric oxide, acetaldehyde, oxygen, sulfur dioxide, and water on NOx reduction activity over NaY zeolite catalyst. Results indicate that with sufficient catalyst volume 90% NOx conversion can be achieved at temperatures relevant to light-duty diesel exhaust (150-350C). Nitric oxide and acetaldehyde react to form N2, HCN, and CO2. Oxygen is necessary in the exhaust feed stream to oxidize NO to NO2 over the catalyst prior to reduction, and water is required to prevent catalyst deactivation. Under conditions of excess acetaldehyde (C1:N>6:1) and low temperature (x conversion is apparently very high; however, the NOx conversion steadily declines with time due to catalytic oxidation of some of the stored (adsorbed) NO to NO2, which can have a significant impact on steady-state NOx conversion. With 250ppm NO in the exhaust feed stream, maximum NOx conversion at 200C can be achieved with =400ppm of acetaldehyde, with higher acetaldehyde concentrations resulting in production of acetic acid and breakthrough of NO2 causing lower NOx conversion levels. Less acetaldehyde is necessary at lower NO concentrations, while more acetaldehyde is required at higher temperatures. Sulfur in the exhaust feed stream as SO2 can cause slow deactivation of the catalyst by poisoning the adsorption and subsequent reaction of nitric oxide and acetaldehyde, particularly at low temperature

  4. Global atmospheric budget of acetaldehyde: 3-D model analysis and constraints from in-situ and satellite observations

    Directory of Open Access Journals (Sweden)

    D. B. Millet

    2010-04-01

    Full Text Available We construct a global atmospheric budget for acetaldehyde using a 3-D model of atmospheric chemistry (GEOS-Chem, and use an ensemble of observations to evaluate present understanding of its sources and sinks. Hydrocarbon oxidation provides the largest acetaldehyde source in the model (128 Tg a−1, a factor of 4 greater than the previous estimate, with alkanes, alkenes, and ethanol the main precursors. There is also a minor source from isoprene oxidation. We use an updated chemical mechanism for GEOS-Chem, and photochemical acetaldehyde yields are consistent with the Master Chemical Mechanism. We present a new approach to quantifying the acetaldehyde air-sea flux based on the global distribution of light absorption due to colored dissolved organic matter (CDOM derived from satellite ocean color observations. The resulting net ocean emission is 57 Tg a−1, the second largest global source of acetaldehyde. A key uncertainty is the acetaldehyde turnover time in the ocean mixed layer, with quantitative model evaluation over the ocean complicated by known measurement artifacts in clean air. Simulated concentrations in surface air over the ocean generally agree well with aircraft measurements, though the model tends to overestimate the vertical gradient. PAN:NOx ratios are well-simulated in the marine boundary layer, providing some support for the modeled ocean source. We introduce the Model of Emissions of Gases and Aerosols from Nature (MEGANv2.1 for acetaldehyde and ethanol and use it to quantify their net flux from living terrestrial plants. Including emissions from decaying plants the total direct acetaldehyde source from the land biosphere is 23 Tg a−1. Other terrestrial acetaldehyde sources include biomass burning (3 Tg a−1 and anthropogenic emissions (2 Tg a−1. Simulated concentrations in the continental boundary layer are generally unbiased and capture the spatial

  5. The Nature of Acid-Catalyzed Acetalization Reaction of 1,2-Propylene Glycol and Acetaldehyde

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Chen; Chen, Hui; Li, Xia; Hu, Jianli; Liang, Baochen [Tianjin University of Technology, Tianjin (China)

    2015-08-15

    We investigated catalytic activity of ion-exchange resins in acetalization of 1,2-propylene glycol with acetaldehyde. The impacts of reaction variables, such as temperature, reaction time, catalyst loading and feedstock composition, on the conversion of 1,2-propylene glycol were measured. The life of the catalyst was also studied. Furthermore, the reaction kinetics of 1,2-propylene glycol acetalization was studied. It was found that reaction rate followed the first order kinetics to acetaldehyde and 1,2-propylene glycol, respectively. Therefore, overall acetalization reaction should follow the second-order reaction kinetics, expressed as r - kC{sup nA}{sub A}C{sup nB}{sub B} = 19.74e{sup -650/T}C{sup 1}{sub A}C{sup 1}{sub B}.

  6. Ambient temperature operated acetaldehyde vapour detection of spray deposited cobalt doped zinc oxide thin film.

    Science.gov (United States)

    Shalini, S; Balamurugan, D

    2016-03-15

    Undoped and Co-doped ZnO thin films were prepared by a home built spray pyrolysis method. X-ray diffraction results indicate that both undoped and Co-doped ZnO have a polycrystalline nature and a preferential orientation peak in the (002) plane. From a field-emission scanning electron micrographs of annealed films, a uniform distribution of nanoparticles along with nanorods was observed. UV-Visible measurement indicated that all the films are transparent in the visible region. The electrical resistance was also reported. The acetaldehyde sensing behaviour of the prepared undoped and Co-doped ZnO thin films was studied using the chemi-resistive method at ambient temperature (∼30 °C). In the presence of 10 ppm of acetaldehyde vapour, the Co-doped ZnO thin films showed good sensing response of 74% with fast response and recovery time of 3 s and 110 s respectively. PMID:26748067

  7. Proton transfer reactions between nitric acid and acetone, hydroxyacetone, acetaldehyde and benzaldehyde in the solid phase.

    Science.gov (United States)

    Lasne, Jérôme; Laffon, Carine; Parent, Philippe

    2012-12-01

    The heterogeneous and homogeneous reactions of acetone, hydroxyacetone, acetaldehyde and benzaldehyde with solid nitric acid (HNO(3)) films have been studied with Reflection-Absorption Infrared Spectroscopy (RAIRS) under Ultra-High Vacuum (UHV) conditions in the 90-170 K temperature range. In the bulk or at the surface of the films, nitric acid transfers its proton to the carbonyl function of the organic molecules, producing protonated acetone-H(+), hydroxyacetone-H(+), acetaldehyde-H(+) and benzaldehyde-H(+), and nitrate anions NO(3)(-), a reaction not observed when nitric acid is previously hydrated [J. Lasne, C. Laffon and Ph. Parent, Phys. Chem. Chem. Phys., 2012, 14, 697]. This provides a molecular-scale description of the carbonyl protonation reaction in an acid medium, the first step of the acid-catalyzed condensation of carbonyl compounds, fuelling the growth of secondary organic aerosols (SOA) in the atmosphere.

  8. Photodissociation of acetaldehyde as a second example of the roaming mechanism

    OpenAIRE

    Houston, P. L.; Kable, S. H.

    2006-01-01

    Product state distributions of the CO produced in the 308-nm photolysis of acetaldehyde show clear evidence of two dissociation mechanisms. One is attributed to the conventional transition state mechanism predicted by theory, with high rotational and translational energy of the CO and a pronounced v⊥J vector correlation. However, as much as 15% of the reaction flux proceeds via another pathway that produces low CO rotational and translational energy, very high CH4 internal energy, and no corr...

  9. Enzymic conversion of ethanol to acetaldehyde as a model recovery system

    Energy Technology Data Exchange (ETDEWEB)

    Kierstan, M.

    1982-10-01

    Ethanol is readily produced by use of traditional fermentation processes using yeasts, and more recently by use of immobilized cell systems. However, the product concentrations obtained in these systems are limited by the inhibitory effects on the microorganisms of the product, ethanol. Furthermore, the dilute product concentrations thus obtained combined with the relatively high boiling point of ethanol result in systems which require a high degree of energy input for product recovery. Recent advances in genetic engineering techniques offer opportunities for improving the characteristics of the yeasts used in ethanol production. These techniques also provide the potential for improving the production yields of microbial enzymes for specific applications. With this consideration in mind work was undertaken on an enzymic system for removal from a fermentation media of an ethanol product which also results in upgrading of the product. Conversion of ethanol to acetaldehyde can be achieved without the involvement of nicotinamide cofactors by use of the enzyme alcohol oxidase obtainable from Candida boidinii. The product acetaldehyde has a relatively low boiling point (21 degrees C) and, therefore, readily evaporates from systems operating above this temperature. This is compatible with normal operating temperatures for ethanol production. The acetaldehyde so produced can then be readily condensed and be utilized or chemically converted to other products. The production of acetaldehyde is accompanied by production of hydrogen peroxide. The effect of the removal of this product, by the use of catalase, on the primary process was also investigated. The system outlined has potential for development into an immobilized enzyme or cell system which may be made compatible with an immobilized Saccharomyces cerevisiae system for improved efficiency of glucose utilization.

  10. Sources and sinks of acetone, methanol, and acetaldehyde in North Atlantic air

    Directory of Open Access Journals (Sweden)

    A. C. Lewis

    2005-03-01

    Full Text Available Measurements of acetone, methanol, acetaldehyde and a range of non-methane hydrocarbons have been made in North Atlantic marine air at the Mace Head observatory. Under maritime conditions the combination of OVOCs (acetone, methanol and 5 acetaldehyde contributed up to 85% of the total mass of measured non methane organics in air and up to 80% of the OH radical organic sink, when compared with the sum of all other organic compounds including non-methane hydrocarbons, DMS and OH-reactive halocarbons (trichloromethane and tetrachloroethylene. The observations showed anomalies in the variance and abundance of acetaldehyde and acetone 10 over that expected for species with a remote terrestrial emission source and OH controlled chemical lifetime. A detailed model incorporating an explicit chemical degradation mechanism indicated in situ formation during air mass transport was on timescales longer than the atmospheric lifetime of precursor hydrocarbons or primary emission. The period over which this process was significant was similar to that of airmass mo15 tion on intercontinental scales, and formation via this route may reproduce that of a widespread diffuse source. The model indicates that continued short chain OVOC formation occurs many days from the point of emission, via longer lived intermediates of oxidation such as organic peroxides and long chain alcohols.

  11. Sources and sinks of acetone, methanol, and acetaldehyde in North Atlantic marine air

    Directory of Open Access Journals (Sweden)

    A. C. Lewis

    2005-01-01

    Full Text Available Measurements of acetone, methanol, acetaldehyde and a range of non-methane hydrocarbons have been made in North Atlantic marine air at the Mace Head observatory. Under maritime conditions the combination of OVOCs (acetone, methanol and acetaldehyde contributed up to 85% of the total mass of measured non methane organics in air and up to 80% of the OH radical organic sink, when compared with the sum of all other organic compounds including non-methane hydrocarbons, DMS and OH-reactive halocarbons (trichloromethane and tetrachloroethylene. The observations showed anomalies in the variance and abundance of acetaldehyde and acetone over that expected for species with a remote terrestrial emission source and OH controlled chemical lifetime. A detailed model incorporating an explicit chemical degradation mechanism indicated in situ formation during air mass transport was on timescales longer than the atmospheric lifetime of precursor hydrocarbons or primary emission. The period over which this process was significant was similar to that of airmass motion on intercontinental scales, and formation via this route may reproduce that of a widespread diffuse source. The model indicates that continued short chain OVOC formation occurs many days from the point of emission, via longer lived intermediates of oxidation such as organic peroxides and long chain alcohols.

  12. Cholesterol Enhances the Toxic Effect of Ethanol and Acetaldehyde in Primary Mouse Hepatocytes.

    Science.gov (United States)

    López-Islas, Anayelly; Chagoya-Hazas, Victoria; Pérez-Aguilar, Benjamin; Palestino-Domínguez, Mayrel; Souza, Verónica; Miranda, Roxana U; Bucio, Leticia; Gómez-Quiroz, Luis Enrique; Gutiérrez-Ruiz, María-Concepción

    2016-01-01

    Obesity and alcohol consumption are risk factors for hepatic steatosis, and both commonly coexist. Our objective was to evaluate the effect of ethanol and acetaldehyde on primary hepatocytes obtained from mice fed for two days with a high cholesterol (HC) diet. HC hepatocytes increased lipid and cholesterol content. HC diet sensitized hepatocytes to the toxic effect of ethanol and acetaldehyde. Cyp2E1 content increased with HC diet, as well as in those treated with ethanol or acetaldehyde, while the activity of this enzyme determined in microsomes increased in the HC and in all ethanol treated hepatocytes, HC and CW. Oxidized proteins were increased in the HC cultures treated or not with the toxins. Transmission electron microscopy showed endoplasmic reticulum (ER) stress and megamitochondria in hepatocytes treated with ethanol as in HC and the ethanol HC treated hepatocytes. ER stress determined by PERK content was increased in ethanol treated hepatocytes from HC mice and CW. Nuclear translocation of ATF6 was observed in HC hepatocytes treated with ethanol, results that indicate that lipids overload and ethanol treatment favor ER stress. Oxidative stress, ER stress, and mitochondrial damage underlie potential mechanisms for increased damage in steatotic hepatocyte treated with ethanol.

  13. Synthesis of nanoporous carbohydrate metal-organic framework and encapsulation of acetaldehyde

    Science.gov (United States)

    Al-Ghamdi, Saleh; Kathuria, Ajay; Abiad, Mohamad; Auras, Rafael

    2016-10-01

    Gamma cyclodextrin (γ-CD) metal organic frameworks (CDMOFs) were synthesized by coordinating γ-CDs with potassium hydroxide (KOH), referred hereafter as CDMOF-a, and potassium benzoate (C7H5KO2), denoted as CDMOF-b. The obtained CDMOF structures were characterized using nitrogen sorption isotherm, thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). High surface areas were achieved by the γ-CD based MOF structures where the Langmuir specific surface areas (SSA) of CDMOF-a and CDMOF-b were determined as 1376 m2 g-1 and 607 m2 g-1; respectively. The dehydrated CDMOF structures demonstrated good thermal stability up to 250 °C as observed by the TGA studies. XRD results for CDMOF-a and CDMOF-b reveal a body centered-cubic (BCC) and trigonal crystal system; respectively. Due to its accessible porous structure and high surface area, acetaldehyde was successfully encapsulated in CDMOF-b. During the release kinetic studies, we observed peak release of 53 μg of acetaldehyde per g of CDMOF-b, which was 100 times greater than previously reported encapsulation in β-CD. However, aldol condensation reaction occurred during encapsulation of acetaldehyde into CDMOF-a. This research work demonstrates the potential to encapsulate volatile organic compounds in CDMOF-b, and their associated release for applications including food, pharmaceuticals and packaging.

  14. Sustainable production of acetaldehyde from lactic acid over the carbon catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Congming; Peng, Jiansheng; Li, Xinli; Zhai, Zhanjie; Gao, Hejun; Liao, Yunwen [China West Normal University, Nanchong (China); Bai, Wei; Jiang, Ning [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu (China)

    2016-01-15

    The synthesis of acetaldehyde from lactic acid over the carbon material catalysts was investigated. The carbon materials were characterized by scanning electron microscopy for morphologic features, by X-ray diffraction for crystal phases, by Fourier transform infrared spectroscopy for functional group structures, by N2 sorption for specific surface area and by ammonia temperature-programed desorption for acidity, respectively. Among the tested carbon catalysts, mesoporous carbon displayed the most excellent catalytic performance. By acidity analysis, the medium acidity is a crucial factor for catalytic performance: more medium acidity favored the formation of acetaldehyde from lactic acid. To verify, we compared the catalytic performance of fresh activated carbon with that of the activated carbon treated by nitric acid. Similarly, the modified activated carbon also displayed better activity due to a drastic increase of medium acidity amount. However, in contrast to fresh carbon nanotube, the treated sample displayed worse activity due to decrease of medium acidity amount. The effect of reaction temperature and time on stream on the catalytic performance was also investigated. Under the optimal reaction conditions, 100% lactic acid conversion and 91.6% acetaldehyde selectivity were achieved over the mesoporous carbon catalyst.

  15. Cholesterol Enhances the Toxic Effect of Ethanol and Acetaldehyde in Primary Mouse Hepatocytes

    Science.gov (United States)

    López-Islas, Anayelly; Chagoya-Hazas, Victoria; Pérez-Aguilar, Benjamin; Palestino-Domínguez, Mayrel; Souza, Verónica; Miranda, Roxana U.; Bucio, Leticia; Gómez-Quiroz, Luis Enrique; Gutiérrez-Ruiz, María-Concepción

    2016-01-01

    Obesity and alcohol consumption are risk factors for hepatic steatosis, and both commonly coexist. Our objective was to evaluate the effect of ethanol and acetaldehyde on primary hepatocytes obtained from mice fed for two days with a high cholesterol (HC) diet. HC hepatocytes increased lipid and cholesterol content. HC diet sensitized hepatocytes to the toxic effect of ethanol and acetaldehyde. Cyp2E1 content increased with HC diet, as well as in those treated with ethanol or acetaldehyde, while the activity of this enzyme determined in microsomes increased in the HC and in all ethanol treated hepatocytes, HC and CW. Oxidized proteins were increased in the HC cultures treated or not with the toxins. Transmission electron microscopy showed endoplasmic reticulum (ER) stress and megamitochondria in hepatocytes treated with ethanol as in HC and the ethanol HC treated hepatocytes. ER stress determined by PERK content was increased in ethanol treated hepatocytes from HC mice and CW. Nuclear translocation of ATF6 was observed in HC hepatocytes treated with ethanol, results that indicate that lipids overload and ethanol treatment favor ER stress. Oxidative stress, ER stress, and mitochondrial damage underlie potential mechanisms for increased damage in steatotic hepatocyte treated with ethanol. PMID:26788255

  16. Cholesterol Enhances the Toxic Effect of Ethanol and Acetaldehyde in Primary Mouse Hepatocytes

    Directory of Open Access Journals (Sweden)

    Anayelly López-Islas

    2016-01-01

    Full Text Available Obesity and alcohol consumption are risk factors for hepatic steatosis, and both commonly coexist. Our objective was to evaluate the effect of ethanol and acetaldehyde on primary hepatocytes obtained from mice fed for two days with a high cholesterol (HC diet. HC hepatocytes increased lipid and cholesterol content. HC diet sensitized hepatocytes to the toxic effect of ethanol and acetaldehyde. Cyp2E1 content increased with HC diet, as well as in those treated with ethanol or acetaldehyde, while the activity of this enzyme determined in microsomes increased in the HC and in all ethanol treated hepatocytes, HC and CW. Oxidized proteins were increased in the HC cultures treated or not with the toxins. Transmission electron microscopy showed endoplasmic reticulum (ER stress and megamitochondria in hepatocytes treated with ethanol as in HC and the ethanol HC treated hepatocytes. ER stress determined by PERK content was increased in ethanol treated hepatocytes from HC mice and CW. Nuclear translocation of ATF6 was observed in HC hepatocytes treated with ethanol, results that indicate that lipids overload and ethanol treatment favor ER stress. Oxidative stress, ER stress, and mitochondrial damage underlie potential mechanisms for increased damage in steatotic hepatocyte treated with ethanol.

  17. Short-term salivary acetaldehyde increase due to direct exposure to alcoholic beverages as an additional cancer risk factor beyond ethanol metabolism

    Directory of Open Access Journals (Sweden)

    Monakhova Yulia B

    2011-01-01

    Full Text Available Abstract Background An increasing body of evidence now implicates acetaldehyde as a major underlying factor for the carcinogenicity of alcoholic beverages and especially for oesophageal and oral cancer. Acetaldehyde associated with alcohol consumption is regarded as 'carcinogenic to humans' (IARC Group 1, with sufficient evidence available for the oesophagus, head and neck as sites of carcinogenicity. At present, research into the mechanistic aspects of acetaldehyde-related oral cancer has been focused on salivary acetaldehyde that is formed either from ethanol metabolism in the epithelia or from microbial oxidation of ethanol by the oral microflora. This study was conducted to evaluate the role of the acetaldehyde that is found as a component of alcoholic beverages as an additional factor in the aetiology of oral cancer. Methods Salivary acetaldehyde levels were determined in the context of sensory analysis of different alcoholic beverages (beer, cider, wine, sherry, vodka, calvados, grape marc spirit, tequila, cherry spirit, without swallowing, to exclude systemic ethanol metabolism. Results The rinsing of the mouth for 30 seconds with an alcoholic beverage is able to increase salivary acetaldehyde above levels previously judged to be carcinogenic in vitro, with levels up to 1000 μM in cases of beverages with extreme acetaldehyde content. In general, the highest salivary acetaldehyde concentration was found in all cases in the saliva 30 sec after using the beverages (average 353 μM. The average concentration then decreased at the 2-min (156 μM, 5-min (76 μM and 10-min (40 μM sampling points. The salivary acetaldehyde concentration depends primarily on the direct ingestion of acetaldehyde contained in the beverages at the 30-sec sampling, while the influence of the metabolic formation from ethanol becomes the major factor at the 2-min sampling point. Conclusions This study offers a plausible mechanism to explain the increased risk for oral

  18. Short-term salivary acetaldehyde increase due to direct exposure to alcoholic beverages as an additional cancer risk factor beyond ethanol metabolism

    Science.gov (United States)

    2011-01-01

    Background An increasing body of evidence now implicates acetaldehyde as a major underlying factor for the carcinogenicity of alcoholic beverages and especially for oesophageal and oral cancer. Acetaldehyde associated with alcohol consumption is regarded as 'carcinogenic to humans' (IARC Group 1), with sufficient evidence available for the oesophagus, head and neck as sites of carcinogenicity. At present, research into the mechanistic aspects of acetaldehyde-related oral cancer has been focused on salivary acetaldehyde that is formed either from ethanol metabolism in the epithelia or from microbial oxidation of ethanol by the oral microflora. This study was conducted to evaluate the role of the acetaldehyde that is found as a component of alcoholic beverages as an additional factor in the aetiology of oral cancer. Methods Salivary acetaldehyde levels were determined in the context of sensory analysis of different alcoholic beverages (beer, cider, wine, sherry, vodka, calvados, grape marc spirit, tequila, cherry spirit), without swallowing, to exclude systemic ethanol metabolism. Results The rinsing of the mouth for 30 seconds with an alcoholic beverage is able to increase salivary acetaldehyde above levels previously judged to be carcinogenic in vitro, with levels up to 1000 μM in cases of beverages with extreme acetaldehyde content. In general, the highest salivary acetaldehyde concentration was found in all cases in the saliva 30 sec after using the beverages (average 353 μM). The average concentration then decreased at the 2-min (156 μM), 5-min (76 μM) and 10-min (40 μM) sampling points. The salivary acetaldehyde concentration depends primarily on the direct ingestion of acetaldehyde contained in the beverages at the 30-sec sampling, while the influence of the metabolic formation from ethanol becomes the major factor at the 2-min sampling point. Conclusions This study offers a plausible mechanism to explain the increased risk for oral cancer associated with

  19. Adsorption and Photocatalytic Kinetics of Visible-Light Response N-Doped TiO2 Nanocatalyst for Indoor Acetaldehyde Removal under Dark and Light Conditions

    Directory of Open Access Journals (Sweden)

    Yu-Hao Lin

    2016-01-01

    Full Text Available Understanding the removal nature of the indoor volatile organic compounds under realistic environment conditions would give clear guidance for the development of air purification devices. The study investigated the removal of indoor acetaldehyde using visible-light-responsive N-doped TiO2 (N-TiO2 photocatalyst under visible-light irradiation (light and in the absence of light (dark. The adsorption kinetics of acetaldehyde onto N-TiO2 followed a pseudo-second-order model. The magnitude of acetaldehyde adsorption is proportional to temperature, and the results were fitted to the Langmuir isotherm model. Moreover, the effect of initial acetaldehyde concentration and visible-light intensity on the photooxidation of acetaldehyde was well described by the Langmuir-Hinshelwood model. Results show that the mesoporous N-TiO2 catalyst had a high ability to absorb acetaldehyde in the dark condition, and then acetaldehyde was subsequently photooxidized under visible-light irradiation. The adsorption capacity was found to increase with decreasing temperature. The negative value of ΔG° and the positive value of ΔS° indicate that the adsorption of acetaldehyde onto N-TiO2 was a spontaneous process. Finally, a reaction scheme for removal process of indoor acetaldehyde by N-TiO2 was proposed.

  20. Kinetics of cytochrome P450 2E1-catalyzed oxidation of ethanol to acetic acid via acetaldehyde.

    Science.gov (United States)

    Bell-Parikh, L C; Guengerich, F P

    1999-08-20

    The P450 2E1-catalyzed oxidation of ethanol to acetaldehyde is characterized by a kinetic deuterium isotope effect that increases K(m) with no effect on k(cat), and rate-limiting product release has been proposed to account for the lack of an isotope effect on k(cat) (Bell, L. C., and Guengerich, F. P. (1997) J. Biol. Chem. 272, 29643-29651). Acetaldehyde is also a substrate for P450 2E1 oxidation to acetic acid, and k(cat)/K(m) for this reaction is at least 1 order of magnitude greater than that for ethanol oxidation to acetaldehyde. Acetic acid accounts for 90% of the products generated from ethanol in a 10-min reaction, and the contribution of this second oxidation has been overlooked in many previous studies. The noncompetitive intermolecular kinetic hydrogen isotope effects on acetaldehyde oxidation to acetic acid ((H)(k(cat)/K(m))/(D)(k(cat)/K(m)) = 4.5, and (D)k(cat) = 1.5) are comparable with the isotope effects typically observed for ethanol oxidation to acetaldehyde, and k(cat) is similar for both reactions, suggesting a possible common catalytic mechanism. Rapid quench kinetic experiments indicate that acetic acid is formed rapidly from added acetaldehyde (approximately 450 min(-1)) with burst kinetics. Pulse-chase experiments reveal that, at a subsaturating concentration of ethanol, approximately 90% of the acetaldehyde intermediate is directly converted to acetic acid without dissociation from the enzyme active site. Competition experiments suggest that P450 2E1 binds acetic acid and acetaldehyde with relatively high K(d) values, which preclude simple tight binding as an explanation for rate-limiting product release. The existence of a rate-determining step between product formation and release is postulated. Also proposed is a conformational change in P450 2E1 occurring during the course of oxidation and the discrimination of P450 2E1 between acetaldehyde and its hydrated form, the gem-diol. This multistep P450 reaction is characterized by kinetic

  1. Biochemical characterization of a bifunctional acetaldehyde-alcohol dehydrogenase purified from a facultative anaerobic bacterium Citrobacter sp. S-77.

    Science.gov (United States)

    Tsuji, Kohsei; Yoon, Ki-Seok; Ogo, Seiji

    2016-03-01

    Acetaldehyde-alcohol dehydrogenase (ADHE) is a bifunctional enzyme consisting of two domains of an N-terminal acetaldehyde dehydrogenase (ALDH) and a C-terminal alcohol dehydrogenase (ADH). The enzyme is known to be important in the cellular alcohol metabolism. However, the role of coenzyme A-acylating ADHE responsible for ethanol production from acetyl-CoA remains uncertain. Here, we present the purification and biochemical characterization of an ADHE from Citrobacter sp. S-77 (ADHE(S77)). Interestingly, the ADHE(S77) was unable to be solubilized from membrane with detergents either 1% Triton X-100 or 1% Sulfobetaine 3-12. However, the enzyme was easily dissociated from membrane by high-salt buffers containing either 1.0 M NaCl or (NH(4))(2)SO(4) without detergents. The molecular weight of a native protein was estimated as approximately 400 kDa, consisting of four identical subunits of 96.3 kDa. Based on the specific activity and kinetic analysis, the ADHES77 tended to have catalytic reaction towards acetaldehyde elimination rather than acetaldehyde formation. Our experimental observation suggests that the ADHES77 may play a pivotal role in modulating intracellular acetaldehyde concentration.

  2. Adsorption and Reaction of Acetaldehyde on Shape-Controlled CeO2 Nanocrystals: Elucidation of Structure-function Relationships

    Energy Technology Data Exchange (ETDEWEB)

    Mann, Amanda K [ORNL; Wu, Zili [ORNL; Calaza, Florencia [Max Planck Society, Fritz Haber Institute; Overbury, Steven {Steve} H [ORNL

    2014-01-01

    CeO2 cubes with {100} facets, octahedra with {111} facets, and wires with highly defective structures were utilized to probe the structure-dependent reactivity of acetaldehyde. Using temperature-programmed desorption (TPD), temperature-programmed surface reactions (TPSR), and in situ infrared spectroscopy it was found that acetaldehyde desorbs unreacted or undergoes reduction, coupling, or C-C bond scission reactions depending on the surface structure of CeO2. Room temperature FTIR indicates that acetaldehyde binds primarily as 1-acetaldehyde on the octahedra, in a variety of conformations on the cubes, including coupling products and acetate and enolate species, and primarily as coupling products on the wires. The percent consumption of acetaldehyde follows the order of wires > cubes > octahedra. All the nanoshapes produce the coupling product crotonaldehyde; however, the selectivity to produce ethanol follows the order wires cubes >> octahedra. The selectivity and other differences can be attributed to the variation in the basicity of the surfaces, defects densities, coordination numbers of surface atoms, and the reducibility of the nanoshapes.

  3. Sensitive gas chromatographic detection of acetaldehyde and acetone using a reduction gas detector

    Science.gov (United States)

    O'Hara, Dean; Singh, Hanwant B.

    1988-01-01

    The response of a newly available mercuric oxide Reduction Gas Detector (RGD-2) to subpicomole and larger quantities of acetaldehyde and acetone is tested. The RGD-2 is found to be capable of subpicomole detection for these carbonyls and is more sensitive than an FID (Flame Ionization Detector) by an order of magnitude. Operating parameters can be further optimized to make the RGD-2 some 20-40 times more sensitive than an FID. The detector is linear over a wide range and is easily adapted to a conventional gas chromatograph (GC). Such a GC-RGD-2 system should be suitable for atmospheric carbonyl measurements in clean as well as polluted environments.

  4. Acetaldehyde reinforcement and motor reactivity in newborns with or without a prenatal history of alcohol exposure

    OpenAIRE

    March, Samanta M.; Culleré, Marcela E.; Abate, Paula; Hernández, José I.; Spear, Norman E.; Molina, Juan C.

    2013-01-01

    Animal models have shown that early ontogeny seems to be a period of enhanced affinity to ethanol. Interestingly, the catalase system that transforms ethanol (EtOH) into acetaldehyde (ACD) in the brain, is more active in the perinatal rat compared to adults. ACD has been found to share EtOH's behavioral effects. The general purpose of the present study was to assess ACD motivational and motor effects in newborn rats as a function of prenatal exposure to EtOH. Experiment 1 evaluated if ACD (0....

  5. Acetaldehyde reinforcement and motor reactivity in newborns with or without a prenatal history of alcohol exposure

    OpenAIRE

    Samanta Mabel March; Spear, Norman E.

    2013-01-01

    Animal models have shown that early ontogeny seems to be a period of enhanced affinity to ethanol. Interestingly, the catalase system, that transforms ethanol (EtOH) into acetaldehyde (ACD) in the brain, is more active in the perinatal rat compared to adults. ACD has been found to share EtOH’s behavioral effects. The general purpose of the present study was to assess ACD motivational and motor effects in newborn rats as a function of prenatal exposure to EtOH. Experiment 1 evaluated if ACD (0...

  6. Influence of pyruvate, threonine and phosphoethanolamine on activities of some acetaldehyde-producing enzymes.

    Science.gov (United States)

    Gerashchenko, D; Gorenshtein, B; Pyzhik, T; Ostrovsky, Y u

    1993-07-01

    Threonine (50 mg/100 g, i.p.) leads to increased hepatic threonine aldolase activity in rats, although endogenous ethanol concentrations remain stable. After pyruvate administration (50 mg/100 g, i.p.), endogenous blood ethanol levels are raised within 30 min, but return to normal at 60 min. The activity of threonine aldolase is decreased in the liver, whereas phosphoethanolamine lyase and pyruvate dehydrogenase activities remain unchanged. Phosphoethanolamine administration (23 mg/100 g, i.p.) did not change the endogenous ethanol concentration or pyruvate dehydrogenase, threonine aldolase and phosphoethanolamine lyase activities. Pyruvate appears to be a better precursor of acetaldehyde than threonine or phosphoethanolamine.

  7. Multi-Walled Carbon Nanotubes as a Catalyst for Gas-Phase Oxidation of Ethanol to Acetaldehyde.

    Science.gov (United States)

    Wang, Jia; Huang, Rui; Feng, Zhenbao; Liu, Hongyang; Su, Dangsheng

    2016-07-21

    Multi-walled carbon nanotubes (CNTs) were directly used as a sustainable and green catalyst to convert ethanol into acetaldehyde in the presence of molecular oxygen. The C=O groups generated on the nanocarbon surface were demonstrated as active sites for the selective oxidation of ethanol to acetaldehyde. The transformation of disordered carbon debris on the CNT surface to ordered graphitic structures induced by thermal-treatment significantly enhanced the stability of the active C=O groups, and thus the catalytic performance. A high reactivity with approximately 60 % ethanol conversion and 93 % acetaldehyde selectivity was obtained over the optimized CNT catalyst at 270 °C. More importantly, the catalytic performance was quite stable even after 500 h, which is comparable with a supported gold catalyst. The robust catalytic performance displayed the potential application of CNTs in the industrial catalysis field. PMID:27282126

  8. Oxidation of Ethanol to Acetaldehyde over Na-promoted vanadium oxide catalysts

    International Nuclear Information System (INIS)

    Sodium-promoted vanadium oxide catalysts supported on MCM-41 and TiO2 (anatase) were investigated for the partial oxidation of ethanol to acetaldehyde. The catalysts were prepared by incipient wetness impregnation with a vanadium oxide content of 6 wt. %. The experimental characterization was performed by X-ray diffraction (XRD), N2 adsorption, temperature programmed reduction (TPR), and diffuse reflectance UV-Vis. Temperature programmed oxidation (TPO) was also used to identify carbon deposits on the spent catalysts. The presence of sodium plays a strong role in the dispersion and reducibility of the vanadium species as detected by TPR analysis and optical absorption spectroscopy. While sodium addition increases the dispersion of the VOx species, its presence also decreases their reducibility. Additionally, TPO of the spent catalysts revealed that an increase in the Na loading decreases the carbon deposition during reaction. In the case of the catalysts supported on MCM-41, these modifications were mirrored by a change in the activity and selectivity to acetaldehyde. Additionally, on the VOx/TiO2 catalysts the catalytic activity decreased with increasing sodium content in the catalyst. A model in which sodium affects dispersion, reducibility and also acidity of the supported-vanadia species is proposed to explain all these observations

  9. The (impossible?) formation of acetaldehyde on the grain surfaces: insights from quantum chemical calculations

    CERN Document Server

    Enrique-Romero, Joan; Ceccarelli, Cecilia; Balucani, Nadia

    2016-01-01

    Complex Organic Molecules (COMs) have been detected in the interstellar medium (ISM). However, it is not clear whether their synthesis occurs on the icy surfaces of interstellar grains or via a series of gas-phase reactions. As a test case of the COMs synthesis in the ISM, we present new quantum chemical calculations on the formation of acetaldehyde (CH3CHO) from the coupling of the HCO and CH3 radicals, both in gas phase and on water ice surfaces. The binding energies of HCO and CH3 on the amorphous water ice were also computed (2333 and 734 K, respectively). Results indicate that, in gas phase, the products could be either CH3CHO, CH4 + CO, or CH3OCH, depending on the relative orientation of the two radicals. However, on the amorphous water ice, only the CH4 + CO product is possible due to the geometrical constraints imposed by the water ice surface. Therefore, acetaldehyde cannot be synthesized by the CH3 + HCO coupling on the icy grains. We discuss the implications of these results and other cases, such a...

  10. Shock Tube Measurement for the Dissociation Rate Constant of Acetaldehyde Using Sensitive CO Diagnostics.

    Science.gov (United States)

    Wang, Shengkai; Davidson, David F; Hanson, Ronald K

    2016-09-01

    The rate constant of acetaldehyde thermal dissociation, CH3CHO = CH3 + HCO, was measured behind reflected shock waves at temperatures of 1273-1618 K and pressures near 1.6 and 0.34 atm. The current measurement utilized sensitive CO diagnostics to track the dissociation of CH3CHO via oxygen atom balance and inferred the title rate constant (k1) from CO time histories obtained in pyrolysis experiments of 1000 and 50 ppm of CH3CHO/Ar mixtures. By using dilute test mixtures, the current study successfully suppressed the interferences from secondary reactions and directly determined the title rate constant as k1(1.6 atm) = 1.1 × 10(14) exp(-36 700 K/T) s(-1) over 1273-1618 K and k1(0.34 atm) = 5.5 × 10(12) exp(-32 900 K/T) s(-1) over 1377-1571 K, with 2σ uncertainties of approximately ±30% for both expressions. Example simulations of existing reaction mechanisms updated with the current values of k1 demonstrated substantial improvements with regards to the acetaldehyde pyrolysis chemistry. PMID:27523494

  11. Interaction of yeasts with the products resulting from the condensation reaction between (+)-catechin and acetaldehyde.

    Science.gov (United States)

    Lopez-Toledano, Azahara; Villaño-Valencia, Debora; Mayen, Manuel; Merida, Julieta; Medina, Manuel

    2004-04-21

    The condensation reaction between (+)-catechin and acetaldehyde was studied in model solutions in the presence and absence yeasts in order to evaluate its contribution to color changes in fermented drinks such as white wine. On the basis of the results, the yeasts retain the oligomers produced in the reaction, their retention ability increasing for higher polymerization degrees. As a result, the color of model solutions, measured as the absorbance at 420 nm, was found to decrease after the addition of yeasts. On the other hand, the yeasts exhibited no inhibitory effect on the condensation reaction, which took place at the same rate in their presence and absence. At acidity levels and reactant concentrations similar to those in wine, with acetaldehyde in high concentration as it is present in sherry wines, the reaction was found to occur very slowly. Taking into account that Yeasts are present during most of the winemaking process; consequently, they retain oligomers, and the studied reaction could mainly contribute to the alteration of the color of white wine after bottling. PMID:15080649

  12. The (impossible?) formation of acetaldehyde on the grain surfaces: insights from quantum chemical calculations

    Science.gov (United States)

    Enrique-Romero, J.; Rimola, A.; Ceccarelli, C.; Balucani, N.

    2016-06-01

    Complex Organic Molecules (COMs) have been detected in the interstellar medium (ISM). However, it is not clear whether their synthesis occurs on the icy surfaces of interstellar grains or via a series of gas-phase reactions. As a test case of the COMs synthesis in the ISM, we present new quantum chemical calculations on the formation of acetaldehyde (CH3CHO) from the coupling of the HCO and CH3 radicals, both in gas phase and on water ice surfaces. The binding energies of HCO and CH3 on the amorphous water ice were also computed (2333 and 734 K, respectively). Results indicate that, in gas phase, the products could be either CH3CHO, CH4 + CO, or CH3OCH, depending on the relative orientation of the two radicals. However, on the amorphous water ice, only the CH4 + CO product is possible due to the geometrical constraints imposed by the water ice surface. Therefore, acetaldehyde cannot be synthesized by the CH3 + HCO coupling on the icy grains. We discuss the implications of these results and other cases, such as ethylene glycol and dimethyl ether, in which similar situations can occur, suggesting that formation of these molecules on the grain surfaces might be unlikely.

  13. Thz Spectroscopy of 13C Isotopic Species of a "weed": Acetaldehyde

    Science.gov (United States)

    Margulès, L.; Motiyenko, R. A.; Guillemin, J.-C.

    2011-06-01

    Our studies of the isotopic species of 13C and D isotopologues of methyl formate (HCOOCH_3), have allowed the detection of more than 600 lines in Orion. This confirms that many observed U-lines are coming from isotopic species of one of the most abundant molecules in space. Since its first detection in 1976 in SgrB2 and in Orion A, acetaldehyde (CH_3CHO) was detected in many other numerous objects. If its deuterated species (CD_3CHO and CH_3CDO) have been previously studied in the millimeterwave range, the data concerning the 13C species are limited to few lines measured in 1957 up to 40 GHz. In this context we decided to study the 13C species of acetaldehyde. Acetaldehyde molecule displays a large amplitude motion: the hindered rotation of the methyl group with respect to the rest of the molecule. The analysis is performed with the Rho Axis Method. Recent versions of the codes include high orders term in order to reproduce the observed frequencies for large quantum numbers values as J-values as high as 70a,b,. Measurements and analysis of the rotational spectra of 13C isotopic species are in progress in Lille with a solid-state submillimetre-wave spectrometer (50-950 GHz), the first results will be presented. This work is supported by the contract ANR-08-BLAN-0054 and by the Programme National de Physico-Chimie du Milieu Interstellaire (PCMI-CNRS). Carvajal, M.; Margulès, L.; Tercero, B.; et al.A&A 500, (2009) 1109 Margulès, L.; Huet, T. R.; Demaison J.; et al.,ApJ 714, (2010) 1120. Ikeda, M.; Ohishi, M.; Nummelin, A.; et al., ApJ, 560, (2001) 792 Kleiner, I.; Lopez, J.-C.; Blanco, S.; et al.J. Mol. Spectrosc. 197, (1999) 275 Elkeurti M.; Coudert, L. H.; Medvedev, I. R.; et al.J. Mol. Spectrosc. 263, (2010) 145 Kilb, R.W.; Lin, C.C.; and Wilson, E.B.J. Chem. Phys. 26, (1957) 1695 Kleiner, I. J. Mol. Spectrosc. 260, (2010) 1 Ilyushin, V.V.; Kryvda, A; and Alekseev, E;J. Mol. Spectrosc. 255, (2009) 32

  14. Acetaldehyde as an Intermediate in the Electroreduction of Carbon Monoxide to Ethanol on Oxide-Derived Copper

    DEFF Research Database (Denmark)

    Bertheussen, Erlend; Verdaguer Casadevall, Arnau; Ravasio, Davide;

    2016-01-01

    Oxide-derived copper (OD-Cu) electrodes exhibit unprecedented CO reduction performance towards liquid fuels, producing ethanol and acetate with >50 % Faradaic efficiency at −0.3 V (vs. RHE). By using static headspace-gas chromatography for liquid phase analysis, we identify acetaldehyde as a mino...

  15. Experimental and modeling study of the oxidation of acetaldehyde in an atmospheric-pressure pulsed corona discharge

    Science.gov (United States)

    Klett, C.; Touchard, S.; Vega-Gonzalez, A.; Redolfi, M.; Bonnin, X.; Hassouni, K.; Duten, X.

    2012-08-01

    This paper reports the results obtained for the degradation of acetaldehyde by an atmospheric plasma corona discharge working in a pulsed regime. It was shown that a few hundred ppm of acetaldehyde diluted in a pure N2 gas flow can be removed up to 80% by a discharge fed with an electric power lower than 1 W. Under the same conditions, adding up to 5% of O2 allowed the removal of up to 95% of the initial acetaldehyde. The main identified end products were CO2, CO and methanol. A quasi-homogeneous zero-dimensional chemical model was developed to investigate the respective efficiency of the discharge and post-discharge periods in the global removal of the pollutant. The identified main pathways of acetaldehyde degradation were quenching of N2 metastable states during plasma pulses and oxidation by O and OH radicals during the post-discharge. This latter contribution increased with input power because of ozone accumulation in the gas mixture acting as an additional oxygen reservoir.

  16. Direct measurement of Criegee intermediate (CH2OO) reactions with acetone, acetaldehyde, and hexafluoroacetone.

    Science.gov (United States)

    Taatjes, Craig A; Welz, Oliver; Eskola, Arkke J; Savee, John D; Osborn, David L; Lee, Edmond P F; Dyke, John M; Mok, Daniel W K; Shallcross, Dudley E; Percival, Carl J

    2012-08-14

    Criegee biradicals, i.e., carbonyl oxides, are critical intermediates in ozonolysis and have been implicated in autoignition chemistry and other hydrocarbon oxidation systems, but until recently the direct measurement of their gas-phase kinetics has not been feasible. Indirect determinations of Criegee intermediate kinetics often rely on the introduction of a scavenger molecule into an ozonolysis system and analysis of the effects of the scavenger on yields of products associated with Criegee intermediate reactions. Carbonyl species, in particular hexafluoroacetone (CF(3)COCF(3)), have often been used as scavengers. In this work, the reactions of the simplest Criegee intermediate, CH(2)OO (formaldehyde oxide), with three carbonyl species have been measured by laser photolysis/tunable synchrotron photoionization mass spectrometry. Diiodomethane photolysis produces CH(2)I radicals, which react with O(2) to yield CH(2)OO + I. The formaldehyde oxide is reacted with a large excess of a carbonyl reactant and both the disappearance of CH(2)OO and the formation of reaction products are monitored. The rate coefficient for CH(2)OO + hexafluoroacetone is k(1) = (3.0 ± 0.3) × 10(-11) cm(3) molecule(-1) s(-1), supporting the use of hexafluoroacetone as a Criegee-intermediate scavenger. The reactions with acetaldehyde, k(2) = (9.5 ± 0.7) × 10(-13) cm(3) molecule(-1) s(-1), and with acetone, k(3) = (2.3 ± 0.3) × 10(-13) cm(3) molecule(-1) s(-1), are substantially slower. Secondary ozonides and products of ozonide isomerization are observed from the reactions of CH(2)OO with acetone and hexafluoroacetone. Their photoionization spectra are interpreted with the aid of quantum-chemical and Franck-Condon-factor calculations. No secondary ozonide was observable in the reaction of CH(2)OO with acetaldehyde, but acetic acid was identified as a product under the conditions used (4 Torr and 293 K). PMID:22481381

  17. Acetonitrile and N-Chloroacetamide Formation from the Reaction of Acetaldehyde and Monochloramine.

    Science.gov (United States)

    Kimura, Susana Y; Vu, Trang Nha; Komaki, Yukako; Plewa, Michael J; Mariñas, Benito J

    2015-08-18

    Nitriles and amides are two classes of nitrogenous disinfection byproducts (DBPs) associated with chloramination that are more cytotoxic and genotoxic than regulated DBPs. Monochloramine reacts with acetaldehyde, a common ozone and free chlorine disinfection byproduct, to form 1-(chloroamino)ethanol. Equilibrium (K1) and forward and reverse rate (k1,k-1) constants for the reaction between initial reactants and 1-(chloroamino)ethanol were determined between 2 and 30 °C. Activation energies for k1 and k-1 were 3.04 and 45.2 kJ·mol(-1), respectively, and enthalpy change for K1 was -42.1 kJ·mol(-1). In parallel reactions, 1-(chloroamino)ethanol (1) slowly dehydrated (k2) to (chloroimino)ethane that further decomposed to acetonitrile and (2) was oxidized (k3) by monochloramine to produce N-chloroacetamide. Both reactions were acid/base catalyzed, and rate constants were characterized at 10, 18, and 25 °C. Modeling for drinking water distribution system conditions showed that N-chloroacetamide and acetonitrile concentrations were 5-9 times higher at pH 9.0 compared to 7.8. Furthermore, acetonitrile concentration was found to form 7-10 times higher than N-chloroacetamide under typical monochloramine and acetaldehyde concentrations. N-chloroacetamide cytotoxicity (LC50 = 1.78 × 10(-3) M) was comparable to dichloroacetamide and trichloroacetamide, but less potent than N,2-dichloroacetamide and chloroacetamide. While N-chloroacetamide was not found to be genotoxic, N,2-dichloroacetamide genotoxic potency (5.19 × 10(-3) M) was on the same order of magnitude as chloroacetamide and trichloroacetamide.

  18. Acetaldehyde as an underestimated risk factor for cancer development: role of genetics in ethanol metabolism

    Science.gov (United States)

    Stickel, Felix

    2009-01-01

    Chronic ethanol consumption is a strong risk factor for the development of certain types of cancer including those of the upper aerodigestive tract, the liver, the large intestine and the female breast. Multiple mechanisms are involved in alcohol-mediated carcinogenesis. Among those the action of acetaldehyde (AA), the first metabolite of ethanol oxidation is of particular interest. AA is toxic, mutagenic and carcinogenic in animal experiments. AA binds to DNA and forms carcinogenic adducts. Direct evidence of the role of AA in alcohol-associated carcinogenesis derived from genetic linkage studies in alcoholics. Polymorphisms or mutations of genes coding for AA generation or detoxifying enzymes resulting in elevated AA concentrations are associated with increased cancer risk. Approximately 40% of Japanese, Koreans or Chinese carry the AA dehydrogenase 2*2 (ALDH2*2) allele in its heterozygous form. This allele codes for an ALDH2 enzyme with little activity leading to high AA concentrations after the consumption of even small amounts of alcohol. When individuals with this allele consume ethanol chronically, a significant increased risk for upper alimentary tract and colorectal cancer is noted. In Caucasians, alcohol dehydrogenase 1C*1 (ADH1C*1) allele encodes for an ADH isoenzyme which produces 2.5 times more AA than the corresponding allele ADH1C*2. In studies with moderate to high alcohol intake, ADH1C*1 allele frequency and rate of homozygosity was found to be significantly associated with an increased risk for cancer of the upper aerodigestive tract, the liver, the colon and the female breast. These studies underline the important role of acetaldehyde in ethanol-mediated carcinogenesis. PMID:19847467

  19. Synthesis and Characterisation of Porous Titania-Silica Composite Aerogel for NO(x) and Acetaldehyde Removal.

    Science.gov (United States)

    Lee, Kwang Young; Park, Se Min; Kim, Jong Beom; El Saliby, Ibrahim; Shahid, Mohammad; Kim, Geon-Joong; Shon, Ho Kyong; Kim, Jong-Ho

    2016-05-01

    In this study, the synthesis of porous titania-silica (TiO2-SiO2) composite aerogel at ambient pressure by using non-hazardous chemicals as a source of silica was investigated. TiO2-SiO2 composite aerogels were characterised and their photocatalytic performances were investigated for the removal efficiency of acetaldehyde and NO(x) under UV light. Results showed that porous composite aerogel with aggregated morphology, high surface area and an increased mesoporosity were formed. TiO2-SiO2(1.8) composite, with high Ti/Si ratio, showed the best results in terms of photocatalytic removal of acetaldehyde and nitrogen oxide.

  20. Synthesis and Characterisation of Porous Titania-Silica Composite Aerogel for NO(x) and Acetaldehyde Removal.

    Science.gov (United States)

    Lee, Kwang Young; Park, Se Min; Kim, Jong Beom; El Saliby, Ibrahim; Shahid, Mohammad; Kim, Geon-Joong; Shon, Ho Kyong; Kim, Jong-Ho

    2016-05-01

    In this study, the synthesis of porous titania-silica (TiO2-SiO2) composite aerogel at ambient pressure by using non-hazardous chemicals as a source of silica was investigated. TiO2-SiO2 composite aerogels were characterised and their photocatalytic performances were investigated for the removal efficiency of acetaldehyde and NO(x) under UV light. Results showed that porous composite aerogel with aggregated morphology, high surface area and an increased mesoporosity were formed. TiO2-SiO2(1.8) composite, with high Ti/Si ratio, showed the best results in terms of photocatalytic removal of acetaldehyde and nitrogen oxide. PMID:27483782

  1. An improved biosensor for acetaldehyde determination using a bienzymatic strategy at poly(neutral red) modified carbon film electrodes

    OpenAIRE

    Ghica, Mariana Emilia; Pauliukaite, Rasa; Marchand, Nicolas; Devic, Eric; Brett, Christopher M. A.

    2007-01-01

    Improved biosensors for acetaldehyde determination have been developed using a bienzymatic strategy, based on a mediator-modified carbon film electrode and co-immobilisation of NADH oxidase and aldehyde dehydrogenase. Modification of the carbon film electrode with poly(neutral red) mediator resulted in a sensitive, low-cost and reliable NADH detector. Immobilisation of the enzymes was performed using encapsulation in a sol-gel matrix or cross-linking with glutaraldehyde. The bienzymatic biose...

  2. Acetaldehyde as a drug of abuse: insight into AM281 administration on operant-conflict paradigm in rats.

    OpenAIRE

    Plescia, Fulvio; Brancato, Anna; Marino, Rosa A. M.; Cannizzaro, Carla

    2013-01-01

    Increasing evidence focuses on acetaldehyde (ACD) as the mediator of the rewarding and motivational properties of ethanol. Indeed, ACD stimulates dopamine release in the nucleus accumbens and it is self-administered under different conditions. Besides the dopaminergic transmission, the endocannabinoid system has been reported to play an important role in ethanol central effects, modulating primary alcohol rewarding effect, drug-seeking, and relapse behavior. Drug motivational properties are h...

  3. Pharmacological recruitment of aldehyde dehydrogenase 3A1 (ALDH3A1) to assist ALDH2 in acetaldehyde and ethanol metabolism in vivo

    Science.gov (United States)

    Chen, Che-Hong; Cruz, Leslie A.; Mochly-Rosen, Daria

    2015-01-01

    Correcting a genetic mutation that leads to a loss of function has been a challenge. One such mutation is in aldehyde dehydrogenase 2 (ALDH2), denoted ALDH2*2. This mutation is present in ∼0.6 billion East Asians and results in accumulation of toxic acetaldehyde after consumption of ethanol. To temporarily increase metabolism of acetaldehyde in vivo, we describe an approach in which a pharmacologic agent recruited another ALDH to metabolize acetaldehyde. We focused on ALDH3A1, which is enriched in the upper aerodigestive track, and identified Alda-89 as a small molecule that enables ALDH3A1 to metabolize acetaldehyde. When given together with the ALDH2-specific activator, Alda-1, Alda-89 reduced acetaldehyde-induced behavioral impairment by causing a rapid reduction in blood ethanol and acetaldehyde levels after acute ethanol intoxication in both wild-type and ALDH2-deficient, ALDH2*1/*2, heterozygotic knock-in mice. The use of a pharmacologic agent to recruit an enzyme to metabolize a substrate that it usually does not metabolize may represent a novel means to temporarily increase elimination of toxic agents in vivo. PMID:25713355

  4. Taraxerone enhances alcohol oxidation via increases of alcohol dehyderogenase (ADH) and acetaldehyde dehydrogenase (ALDH) activities and gene expressions.

    Science.gov (United States)

    Sung, Chang-Keun; Kim, Seung-Mi; Oh, Chang-Jin; Yang, Sun-A; Han, Byung-Hee; Mo, Eun-Kyoung

    2012-07-01

    The present study, taraxerone (d-friedoolean-14-en-3-one) was isolated from Sedum sarmentosum with purity 96.383%, and its enhancing effects on alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) activities were determined: EC(50) values were 512.42 ± 3.12 and 500.16 ± 3.23 μM for ADH and ALDH, respectively. In order to obtain more information on taraxerone related with the alcohol metabolism, 40% ethanol (5 mL/kg body weight) with 0.5-1mM of taraxerone were administered to mice. The plasma alcohol and acetaldehyde concentrations of taraxerone-treated groups were significantly lowered than those of the control group (p<0.01): approximately 20-67% and 7-57% lowered for plasma alcohol and acetaldehyde, respectively. Compare to the control group, the ADH and ALDH expressions in the liver tissues were abruptly increased in the taraxerone-treated groups after ethanol exposure. In addition, taraxerone prevented catalase, superoxide dismutase, and reduced glutathione concentrations from the decrease induced by ethanol administration with the concentration dependent manner.

  5. Atmospheric formaldehyde and acetaldehyde at the campus University of Hiroshima, Japan

    Directory of Open Access Journals (Sweden)

    Sonia Naomi Nomi

    2010-09-01

    Full Text Available Ambient levels of formaldehyde (HCHO and acetaldehyde (CH3CHO were measured at Hiroshima (Japan during spring and summer of 2005. Measurements of O3, NOx, and SO2 were simultaneously conducted, in an attempt to identify temporal profiles and sources for these aldehydes. Atmospheric aldehydes were collected using C18 silica gel cartridges coated with an acidic solution of 2, 4-dinitrophenylhydrazine (2,4-DNPH and analyzed by high performance liquid chromatography with UV/VIS detection adjusted to 360 nm. Summer concentrations were higher than spring levels. FA concentrations during spring period ranged from 0.50 to 1.05 ppb and AA concentrations ranged from 0.17 to 1.31 ppb; during summer their concentrations ranged from 1.55 to 4.12 ppb and 0. 34 to 2.03 ppb. Average FA/AA in spring and summer were 3.09 and 3.72 suggesting biogenic emissions of aldehydes. The levels of FA and AA, their temporal variations, and their concentration ratio (FA/AA indicated that photochemical reactions contributed significantly to the formation of atmospheric aldehydes at the study site.

  6. Acetaldehyde metabolism by brain mitochondria from UChA and UChB rats.

    Science.gov (United States)

    Quintanilla, M E; Tampier, L

    1995-01-01

    The acetaldehyde (AcH) oxidizing capacity of total brain homogenates from the genetically high-ethanol consumer (UChB) appeared to be greater than that of the low-ethanol consumer (UChA) rats. To gain further information about this strain difference, the activity of aldehyde dehydrogenase (AIDH) in different subcellular fractions of whole brain homogenates from naive UChA and UChB rat strains of both sexes has been studied by measuring the rate of AcH disappearance and by following the reduction of NAD to NADH. The results demonstrated that the higher capacity of brain homogenates from UChB rats to oxidize AcH when compared to UChA ones was because the UChB mitochondrial low Km AIDH exhibits a much greater affinity for NAD than that of the UChA rats, as evidenced by four-to fivefold differences in the Km values for NAD. But the dehydrogenases from both strains exhibited a similar maximum rate at saturating NAD concentrations. Because intact brain mitochondria isolated from UChB rats oxidized AcH at a higher rate than did mitochondria from UChA rats only in state 4, but not in state 3, this strain difference in AIDH activity might be restricted in vivo to NAD disposition.

  7. Spectroscopic analysis, AIM, NLO and VCD investigations of acetaldehyde thiosemicarbazone using quantum mechanical simulations

    Science.gov (United States)

    Moorthy, N.; Prabakar, P. C. Jobe; Ramalingam, S.; Govindarajan, M.; Gnanamuthu, S. Joshua; Pandian, G. V.

    2016-08-01

    The prepared Acetaldehyde thiosemicarbazone (ATSC) have been investigated by both the experimental and theoretical methods; through this work, the essentiality of elucidation of molecular fragments source linear and non-linear optical properties was explored. The stability of the structure and entire calculations have been performed on HF and B3LYP methods with 6-311++G(d,p) level of basis set. The Mulliken charge profile, electronic, optical and hyper polarizability analyses have been carried out in order to evaluate nonlinear optical (NLO) performance of the present compound. The exact optical location of the ATSC was determined by executing UV-Visible calculations on TDSCF method. The existence of the molecular group for the inducement and tuning of NLO properties were thoroughly investigated by performing fundamental vibrational investigation. The optical energy transformation among frontier molecular levels has been described in UV-Visible region. The Gibbs energy coefficient of thermodynamic functions was monitored in different temperature and it was found constant irrespective of temperatures. The appearance of different chemical environment of H and C was monitored from the 1H and 13C NMR spectra. The vibrational optical polarization characteristics with respect to molecular composition in the compound have been studied by VCD spectrum. The bond critical point, Laplacian of electron density, electron kinetic energy density and total electron energy density have calculated and analysed using AIM study.

  8. Recombinant human diamine oxidase activity is not inhibited by ethanol, acetaldehyde, disulfiram, diethyldithiocarbamate or cyanamide.

    Science.gov (United States)

    Bartko, Johann; Gludovacz, Elisabeth; Petroczi, Karin; Borth, Nicole; Jilma, Bernd; Boehm, Thomas

    2016-08-01

    Human diamine oxidase (hDAO, EC 1.4.3.22) is the key enzyme in the degradation of extracellular histamine. Consumption of alcohol is a known trigger of mast cell degranulation in patients with mast cell activation syndrome. Ethanol may also interfere with enzymatic histamine degradation, but reports on the effects on DAO activity are controversial. There are also conflicting reports whether disulfiram, an FDA-approved agent in the treatment of alcohol dependence, inhibits DAO. We therefore investigated the inhibitory potential of ethanol and disulfiram and their metabolites on recombinant human DAO (rhDAO) in three different assay systems. Relevant concentrations of ethanol, acetaldehyde, and acetate did not inhibit rhDAO activity in an in vitro assay system using horseradish peroxidase (HRP) -mediated luminol oxidation. The aldehyde dehydrogenase (ALDH; EC 1.2.1.3) inhibitors cyanamide and its dimer dicyanamide also had no effect on DAO activity. In one assay system, the irreversible ALDH inhibitor disulfiram and its main metabolite diethyldithiocarbamate seemed to inhibit DAO activity. However, the decreased product formation was not due to a direct block of DAO activity but resulted from inhibition of peroxidase employed in the coupled system. Our in vitro data do not support a direct blocking effect of ethanol, disulfiram, and their metabolites on DAO activity in vivo. PMID:27401969

  9. Photocatalytic Oxidation of a Volatile Organic Component of Acetaldehyde Using Titanium Oxide Nanotubes

    Directory of Open Access Journals (Sweden)

    Yifeng Wang

    2007-01-01

    Full Text Available Titanium oxide nanotubes are prepared and treated with Au (Au/nanotube sample and Pt (Pt/nanotube sample, and the photoactivity of these catalysts compared to a standard Degussa P25 photocatalyst is investigated. The samples were analyzed using X-ray diffraction, field emission gun scanning transmission electron microscopy (STEM. Both high-resolution TEM images and high-angle annular dark-field (HAAD images were recorded for the specimens. Oxidation of acetaldehyde was used to test the efficiency of the catalysts. Nanotube samples showed better photoactivity than the standard P25, because the P25 titania deactivates quickly. Enhanced reactivity of the nanotube is related to surface charge polarity developed on outer and inner surfaces due to the difference in overlap of oxygen anions that resulted from curving of octahedral sheets. A tentative and qualitative surface polarity model is proposed for enhancing electron-hole pair separation. The inner surface benefits reduction; whereas, the outer surface benefits oxidation reactions. Both the metal identity and the size of the metal particles in the nanotubes affected the photocatalytic activity. Specifically, the addition of platinum increased the activity significantly, and increased the total yield. The addition of gold had lesser impact compared to the platinum. Formation of Pt large nanoparticles on the nanotube surfaces reduces the oxidation reactivity.

  10. Detecting ethanol and acetaldehyde by simple and ultrasensitive fluorimetric methods in compound foods.

    Science.gov (United States)

    Zachut, M; Shapiro, F; Silanikove, N

    2016-06-15

    There is a need for simple, accurate, and rapid analysis of ethanol (Eth) and acetaldehyde (AA) in a wide variety of beverages and foods. A novel enzymatic assay coupled to formation of fluorescent chromophore is presented. Eth detection was further improved by adding semicarbazide to the reaction mixture, which interacts with AA and prevents its inhibitory effect on Eth oxidation. The limits of detection of Eth (0.5 mg/L) and AA (0.9 mg/L) are comparable with the performance of modern gas chromatography techniques. The repeatability of Eth and AA detection in various foods (9% on average) was lower than that with commercial kits (23%). The high sensitivity of the developed method enables detection of AA in common foods [e.g., bio-yogurt (12.2 mg/L), and the existence of endogenous Eth (1.8 mg/L) and AA (2.0 mg/L) in bacteria-free non-fermented bovine milk], which could not measured so far by enzymatic methods. PMID:26868576

  11. NOX2 amplifies acetaldehyde-mediated cardiomyocyte mitochondrial dysfunction in alcoholic cardiomyopathy

    Science.gov (United States)

    Brandt, Moritz; Garlapati, Venkata; Oelze, Matthias; Sotiriou, Efthymios; Knorr, Maike; Kröller-Schön, Swenja; Kossmann, Sabine; Schönfelder, Tanja; Morawietz, Henning; Schulz, Eberhard; Schultheiss, Heinz-Peter; Daiber, Andreas; Münzel, Thomas; Wenzel, Philip

    2016-01-01

    Alcoholic cardiomyopathy (ACM) resulting from excess alcohol consumption is an important cause of heart failure (HF). Although it is assumed that the cardiotoxicity of the ethanol (EtOH)-metabolite acetaldehyde (ACA) is central for its development and progression, the exact mechanisms remain obscure. Murine cardiomyocytes (CMs) exposed to ACA or EtOH showed increased superoxide (O2•−) levels and decreased mitochondrial polarization, both being normalized by NADPH oxidase (NOX) inhibition. C57BL/6 mice and mice deficient for the ACA-degrading enzyme mitochondrial aldehyde dehydrogenase (ALDH-2−/−) were fed a 2% EtOH diet for 5 weeks creating an ACA-overload. 2% EtOH-fed ALDH-2−/− mice exhibited a decreased cardiac function, increased heart-to-body and lung-to-body weight ratios, increased cardiac levels of the lipid peroxidation product malondialdehyde (MDA) as well as increased NOX activity and NOX2/glycoprotein 91phox (NOX2/gp91phox) subunit expression compared to 2% EtOH-fed C57BL/6 mice. Echocardiography revealed that ALDH-2−/−/gp91phox−/− mice were protected from ACA-overload-induced HF after 5 weeks of 2% EtOH-diet, demonstrating that NOX2-derived O2•− contributes to the development of ACM. Translated to human pathophysiology, we found increased gp91phox expression in endomyocardial biopsies of ACM patients. In conclusion, ACM is promoted by ACA-driven mitochondrial dysfunction and can be improved by ablation of NOX2/gp91phox. NOX2/gp91phox therefore might be a potential pharmacological target to treat ACM. PMID:27624556

  12. A novel antifungal is active against Candida albicans biofilms and inhibits mutagenic acetaldehyde production in vitro.

    Directory of Open Access Journals (Sweden)

    Mikko T Nieminen

    Full Text Available The ability of C. albicans to form biofilms is a major virulence factor and a challenge for management. This is evident in biofilm-associated chronic oral-oesophageal candidosis, which has been shown to be potentially carcinogenic in vivo. We have previously shown that most Candida spp. can produce significant levels of mutagenic acetaldehyde (ACH. ACH is also an important mediator of candidal biofilm formation. We have also reported that D,L-2-hydroxyisocaproic acid (HICA significantly inhibits planktonic growth of C. albicans. The aim of the present study was to investigate the effect of HICA on C. albicans biofilm formation and ACH production in vitro. Inhibition of biofilm formation by HICA, analogous control compounds or caspofungin was measured using XTT to measure biofilm metabolic activity and PicoGreen as a marker of biomass. Biofilms were visualised by scanning electron microscopy (SEM. ACH levels were measured by gas chromatography. Transcriptional changes in the genes involved in ACH metabolism were measured using RT-qPCR. The mean metabolic activity and biomass of all pre-grown (4, 24, 48 h biofilms were significantly reduced after exposure to HICA (p40 µM of ACH were detected in 24 and 48 h biofilms at both pHs. Interestingly, no ACH production was detected from D-glucose in the presence of HICA at acidic pH (p<0.05. Expression of genes responsible for ACH catabolism was up-regulated by HICA but down-regulated by caspofungin. SEM showed aberrant hyphae and collapsed hyphal structures during incubation with HICA at acidic pH. We conclude that HICA has potential as an antifungal agent with ability to inhibit C. albicans cell growth and biofilm formation. HICA also significantly reduces the mutagenic potential of C. albicans biofilms, which may be important when treating bacterial-fungal biofilm infections.

  13. Effect of Acetaldehyde Intoxication and Withdrawal on NPY Expression: Focus on Endocannabinoidergic System Involvement.

    Science.gov (United States)

    Plescia, Fulvio; Brancato, Anna; Marino, Rosa Anna Maria; Vita, Carlotta; Navarra, Michele; Cannizzaro, Carla

    2014-01-01

    Acetaldehyde (ACD), the first alcohol metabolite, plays a pivotal role in the rewarding, motivational, and addictive properties of the parental compound. Many studies have investigated the role of ACD in mediating neurochemical and behavioral effects induced by alcohol administration, but very little is known about the modulation of neuropeptide systems following ACD intoxication and withdrawal. Indeed, the neuropeptide Y (NPY) system is altered during alcohol withdrawal in key regions for cerebrocortical excitability and neuroplasticity. The primary goal of this research was to investigate the effects of ACD intoxication and withdrawal by recording rat behavior and by measuring NPY immunoreactivity in hippocampus and NAcc, two brain regions mainly involved in processes which encompass neuroplasticity in alcohol dependence. Furthermore, on the basis of the involvement of endocannabinoidergic system in alcohol and ACD reinforcing effects, the role of the selective CB1 receptor antagonist AM281 in modulating NPY expression during withdrawal was assessed. Our results indicate that (i) ACD intoxication induced a reduction in NPY expression in hippocampus and NAcc; (ii) symptoms of physical dependence, similar to alcohol's, were scored at 12 h from the last administration of ACD; and (iii) NPY levels increased in early and prolonged acute withdrawal in both brain regions examined. The administration of AM281 was able to blunt signs of ACD-induced physical dependence, to modulate NPY levels, and to further increase NPY expression during ACD withdrawal both in hippocampus and NAcc. In conclusion, the present study shows that complex plastic changes take place in NPY system during ACD intoxication and subsequent withdrawal in rat hippocampal formation and NAcc. The pharmacological inhibition of CB1 signaling could counteract the neurochemical imbalance associated with ACD, and alcohol withdrawal, likely boosting the setting up of homeostatic functional recovery.

  14. Non-Saccharomyces and Saccharomyces strains co-fermentation increases acetaldehyde accumulation: effect on anthocyanin-derived pigments in Tannat red wines.

    Science.gov (United States)

    Medina, Karina; Boido, Eduardo; Fariña, Laura; Dellacassa, Eduardo; Carrau, Francisco

    2016-07-01

    During fermentation, Saccharomyces cerevisiae releases into the medium secondary metabolic products, such as acetaldehyde, able to react with anthocyanins, producing more stable derived pigments. However, very limited reports are found about non-Saccharomyces effects on grape fermentation. In this study, six non-Saccharomyces yeast strains, belonging to the genera Metschnikowia and Hanseniaspora, were screened for their effect on red wine colour and wine-making capacity under pure culture conditions and mixed with Saccharomyces. An artificial red grape must was prepared, containing a phenolic extract of Tannat grapes that allows monitoring changes of key phenol parameters during fermentation, but without skin solids in the medium. When fermented in pure cultures, S. cerevisiae produced higher concentrations of acetaldehyde and vitisin B (acetaldehyde reaction-dependent) compared to M. pulcherrima M00/09G, Hanseniaspora guillermondii T06/09G, H. opuntiae T06/01G, H. vineae T02/05F and H. clermontiae (A10/82Fand C10/54F). However, co-fermentation of H. vineae and H. clermontiae with S. cerevisiae resulted in a significantly higher concentration of acetaldehyde compared with the pure S. cerevisiae control. HPLC-DAD-MS analysis confirmed an increased formation of vitisin B in co-fermentation treatments when compared to pure Saccharomyces fermentation, suggesting the key role of acetaldehyde. Copyright © 2016 John Wiley & Sons, Ltd.

  15. Brewers' yeast pyruvate decarboxylase produces acetoin from acetaldehyde: a novel tool to study the mechanism of steps subsequent to carbon dioxide loss.

    Science.gov (United States)

    Chen, G C; Jordan, F

    1984-07-31

    A gas-liquid chromatographic technique was developed for the determination of both acetaldehyde and the 3-4% acetoin side product that results from the brewers' yeast pyruvate decarboxylase (EC 4.1.1.1) catalyzed reaction of pyruvic acid. Employing this method enabled the demonstration of the catalysis of acetaldehyde condensation to acetoin by the enzyme. It was found that the acetoin produced enzymatically from pyruvic acid or from acetaldehyde was optically active, thus providing stereochemical information about the reaction. Deuterium kinetic isotope effects (employing CH3CHO and CH3CDO) were determined on the steady-state kinetic parameters to be 4.5 (Vmax) and 3.2 (Vmax/Kappm), respectively. This enabled, for the first time, the estimation of relative kinetic barriers for steps past decarboxylation. It could be concluded that (a) C-H bond scission was part of rate limitation in the enzyme-catalyzed condensation of acetaldehyde to acetoin and that (b) among the steps leading to the release of acetaldehyde, protonation of the key enamine intermediate was part of rate limitation. This latter finding is also directly applicable to the mechanism of pyruvate decarboxylation.

  16. Non-Saccharomyces and Saccharomyces strains co-fermentation increases acetaldehyde accumulation: effect on anthocyanin-derived pigments in Tannat red wines.

    Science.gov (United States)

    Medina, Karina; Boido, Eduardo; Fariña, Laura; Dellacassa, Eduardo; Carrau, Francisco

    2016-07-01

    During fermentation, Saccharomyces cerevisiae releases into the medium secondary metabolic products, such as acetaldehyde, able to react with anthocyanins, producing more stable derived pigments. However, very limited reports are found about non-Saccharomyces effects on grape fermentation. In this study, six non-Saccharomyces yeast strains, belonging to the genera Metschnikowia and Hanseniaspora, were screened for their effect on red wine colour and wine-making capacity under pure culture conditions and mixed with Saccharomyces. An artificial red grape must was prepared, containing a phenolic extract of Tannat grapes that allows monitoring changes of key phenol parameters during fermentation, but without skin solids in the medium. When fermented in pure cultures, S. cerevisiae produced higher concentrations of acetaldehyde and vitisin B (acetaldehyde reaction-dependent) compared to M. pulcherrima M00/09G, Hanseniaspora guillermondii T06/09G, H. opuntiae T06/01G, H. vineae T02/05F and H. clermontiae (A10/82Fand C10/54F). However, co-fermentation of H. vineae and H. clermontiae with S. cerevisiae resulted in a significantly higher concentration of acetaldehyde compared with the pure S. cerevisiae control. HPLC-DAD-MS analysis confirmed an increased formation of vitisin B in co-fermentation treatments when compared to pure Saccharomyces fermentation, suggesting the key role of acetaldehyde. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26888345

  17. Distribution of the thiamin diphosphate C(2)-proton during catalysis of acetaldehyde formation by brewers' yeast pyruvate decarboxylase.

    Science.gov (United States)

    Harris, T K; Washabaugh, M W

    1995-10-31

    The distribution of tritium derived from enzyme-bound [thiazole-2-T]thiamin diphosphate (TDP) during the reaction of pyruvate to form acetaldehyde catalyzed by pyruvate decarboxylase isozymes (PDC; EC 4.1.1.1) from Saccharomyces carlsbergensis was determined under single-turnover conditions ([E] > [S]) in the presence of the nonsubstrate allosteric effector pyruvamide. The specific radioactivity of the [1-L]acetaldehyde product and solvent ([L]H2O) was 43 +/- 4% and 54 +/- 2%, respectively, of the initial specific radioactivity of PDC-bound [thiazole-2-T]TDP and was independent of the extent of the single-turnover reaction. There is little (< or = 3%) or no return of the abstracted C(2)-hydron to the C(2) position of PDC-bound TDP. This provides evidence that the abstracted C(2)-hydron is involved in the specific protonation of the C(alpha) position of the PDC-bound intermediate 2-(1-hydroxyethyl)thiamin diphosphate (HETDP), which is cleaved to form [1-L]acetaldehyde and PDC-bound [thiazole-2-H]TDP. The partial exchange of C(2)-derived tritium into solvent requires that (1) hydron transfer from C(2) occurs to a catalytic-base in which the conjugate catalytic acid is partially shielded from hydron exchange with the solvent, (2) the conjugate catalytic acid transfers the C(2)-derived hydron to the C(alpha) position of HETDP, and (3) hydron transfer to C(2) to regenerate the coenzyme occurs either from solvent directly or from a second catalytic acid of the enzyme that undergoes rapid hydron exchange with the solvent.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Ethanol Metabolism by HeLa Cells Transduced with Human Alcohol Dehydrogenase Isoenzymes: Control of the Pathway by Acetaldehyde Concentration†

    Science.gov (United States)

    Matsumoto, Michinaga; Cyganek, Izabela; Sanghani, Paresh C.; Cho, Won Kyoo; Liangpunsakul, Suthat; Crabb, David W.

    2010-01-01

    Background Human class I alcohol dehydrogenase 2 isoenzymes (encoded by the ADH1B locus) have large differences in kinetic properties; however, individuals inheriting the alleles for the different isoenzymes exhibit only small differences in alcohol elimination rates. This suggests that other cellular factors must regulate the activity of the isoenzymes. Methods The activity of the isoenzymes expressed from ADH1B*1, ADH1B*2, and ADH1B*3 cDNAs was examined in stably transduced HeLa cell lines, including lines which expressed human low Km aldehyde dehydrogenase (ALDH2). The ability of the cells to metabolize ethanol was compared with that of HeLa cells expressing rat class I ADH (HeLa-rat ADH cells), rat hepatoma (H4IIEC3) cells, and rat hepatocytes. Results The isoenzymes had similar protein half-lives in the HeLa cells. Rat hepatocytes, H4IIEC3 cells, and HeLa-rat ADH cells oxidized ethanol much faster than the cells expressing the ADH1B isoenzymes. This was not explained by high cellular NADH levels or endogenous inhibitors; but rather because the activity of the β1 and β2 ADHs were constrained by the accumulation of acetaldehyde, as shown by the increased rate of ethanol oxidation by cell lines expressing β2 ADH plus ALDH2. Conclusion The activity of the human β2 ADH isoenzyme is sensitive to inhibition by acetaldehyde, which likely limits its activity in vivo. This study emphasizes the importance of maintaining a low steady–state acetaldehyde concentration in hepatocytes during ethanol metabolism. PMID:21166830

  19. Preparation of ordered mesoporous Ag/WO3 and its highly efficient degradation of acetaldehyde under visible-light irradiation

    International Nuclear Information System (INIS)

    A highly active photocatalyst, silver loaded mesoporous WO3, was successfully synthesized by an ultrasound assisted insertion method. The photodegradation of a common air pollutant acetaldehyde was adopted to evaluate the photocatalytic performance of the as-prepared sample under visible-light irradiation. The photocatalytic activity was about three and six times higher than that of pure mesoporous WO3 and nitrogen-doped TiO2, respectively. The photocatalytic mechanism was investigated to understand the much enhanced photocatalytic activity, which was mainly attributed to the largely improved electron-hole separation in the Ag-WO3 heterojunction.

  20. Dissociation of acetaldehyde on beta-Mo2C to yield ethylidene and oxo surface groups: a possible pathway for active site formation in heterogeneous olefin metathesis.

    Science.gov (United States)

    Siaj, Mohamed; Reed, Corey; Oyama, S Ted; Scott, Susannah L; McBreen, Peter H

    2004-08-11

    The dissociative adsorption of acetaldehyde on beta-Mo2C was studied using reflection absorption infrared spectroscopy. In contrast to what is observed for all metals previously studied, acetaldehyde undergoes selective carbonyl bond scission on the carbide surface. By comparison to calculated spectra, the surface product is identified as an oxo-ethylidene species. The study thus provides the first extended-range infrared spectrum of a propene metathesis initiator or propagator alkylidene. Aldehydes may be formed in the presence of olefins during the induction period of supported metal oxide olefin metathesis catalysts. Hence, the observed dissociative chemisorption of acetaldehyde suggests a possible answer to the question of how initiator sites are formed in heterogeneous olefin metathesis. This question has never been satisfactorily answered. In the proposed mechanism, aldehydes formed during the induction period subsequently react with the catalyst surface to generate alkylidene sites.

  1. Photochemical fabrication of size-controllable gold nanoparticles on chitosan and their application on catalytic decomposition of acetaldehyde

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Chung-Chin [Department of Environmental Engineering, Vanung University, 1, Van Nung Road, Shuei-Wei Li, Chung-Li City, Taiwan (China); Nano Materials Applications R and D Center, Vanung University, 1, Van Nung Road, Shuei-Wei Li, Chung-Li City, Taiwan (China); Yang, Kuang-Hsuan, E-mail: khy@mail.vnu.edu.tw [Department of Chemical and Materials Engineering, Vanung University, 1, Van Nung Road, Shuei-Wei Li, Chung-Li City, Taiwan (China); Nano Materials Applications R and D Center, Vanung University, 1, Van Nung Road, Shuei-Wei Li, Chung-Li City, Taiwan (China); Liu, Yu-Chuan [Department of Chemical and Materials Engineering, Vanung University, 1, Van Nung Road, Shuei-Wei Li, Chung-Li City, Taiwan (China); Nano Materials Applications R and D Center, Vanung University, 1, Van Nung Road, Shuei-Wei Li, Chung-Li City, Taiwan (China); Chen, Bo-Chuen [Department of Chemical and Materials Engineering, Vanung University, 1, Van Nung Road, Shuei-Wei Li, Chung-Li City, Taiwan (China)

    2010-07-15

    In this work, we report a new pathway to prepare size-controllable gold nanoparticles (NPs) on chitosan (Ch) in aqueous solutions for improving catalytic decomposition of acetaldehyde by pure gold NPs at room temperature. First, Au substrates were cycled in deoxygenated aqueous solutions containing 0.1N NaCl and 1 g/L Ch from -0.28 to +1.22 V vs Ag/AgCl at 500 mV/s for 200 scans. Then the solutions were irradiated with UV lights of different wavelengths to prepare size-controllable Au NPs on Ch. Experimental results indicate that the particle sizes of prepared NPs are increased when UV lights with longer wavelengths were employed. The particle sizes of resulted Au NPs can be controlled from 10 to 50 nm. Moreover, the decomposition of acetaldehydes in wines can be significantly enhanced by ca. 190% of magnitude due to the contribution of the adsorption of Au NPs on Ch.

  2. Study on Streptococcus thermophilus isolated from Qula and associated characteristic of acetaldehyde and diacetyl in their fermented milk.

    Science.gov (United States)

    Zha, Musu; Yu, Jie; Zhang, Yong; Wang, Hongmei; Bai, Na; Qin, Yanting; Liangliang, De; Liu, Wenjun; Zhang, Heping; Bilige, Menghe

    2015-01-01

    In this study, the lactic acid bacterial population of Qula cheese from the Gansu and Sichuan provinces of China were isolated and identified. Eight strains of Streptococcus thermophilus were isolated, of which five strains were selected for further characterization based on their fermentation properties. The changes in a number of parameters, including titration acidity, pH, viable counts, PrtS protease activity and the production of acetaldehyde, diacetyl and organic acid, were monitored during fermentation and the storage of fermented milks produced by the respective strain. All of the strains displaying acidifying capacity and all five fermented milks maintained high viable counts of S. thermophilus from fermentation to storage. Our study found that the changes in the monitored parameters were strain-specific and varied considerably among the five tested strains. Fermented milks produced by strain IMAU80809 had the highest concentration of acetaldehyde and were most favorable in the sensory evaluation. This study confirms that Qula cheese is a good source for isolating novel lactic acid bacterial strains with different fermentation properties, which will be very useful for further development and industrialization of traditionally fermented dairy products. PMID:26018501

  3. Reactive processing of formaldehyde and acetaldehyde in aqueous aerosol mimics: surface tension depression and secondary organic products

    Science.gov (United States)

    Li, Z.; Schwier, A. N.; Sareen, N.; McNeill, V. F.

    2011-11-01

    The reactive uptake of carbonyl-containing volatile organic compounds (cVOCs) by aqueous atmospheric aerosols is a likely source of particulate organic material. The aqueous-phase secondary organic products of some cVOCs are surface-active. Therefore, cVOC uptake can lead to organic film formation at the gas-aerosol interface and changes in aerosol surface tension. We examined the chemical reactions of two abundant cVOCs, formaldehyde and acetaldehyde, in water and aqueous ammonium sulfate (AS) solutions mimicking tropospheric aerosols. Secondary organic products were identified using Aerosol Chemical Ionization Mass Spectrometry (Aerosol-CIMS), and changes in surface tension were monitored using pendant drop tensiometry. Hemiacetal oligomers and aldol condensation products were identified using Aerosol-CIMS. Acetaldehyde depresses surface tension to 65(±2) dyn cm-1 in pure water (a 10% surface tension reduction from that of pure water) and 62(±1) dyn cm-1 in AS solutions (a 20.6% reduction from that of a 3.1 M AS solution). Surface tension depression by formaldehyde in pure water is negligible; in AS solutions, a 9% reduction in surface tension is observed. Mixtures of these species were also studied in combination with methylglyoxal in order to evaluate the influence of cross-reactions on surface tension depression and product formation in these systems. We find that surface tension depression in the solutions containing mixed cVOCs exceeds that predicted by an additive model based on the single-species isotherms.

  4. Reactive processing of formaldehyde and acetaldehyde in aqueous aerosol mimics: Surface tension depression and secondary organic products

    CERN Document Server

    Li, Zhi; Sareen, Neha; McNeill, V Faye

    2011-01-01

    The reactive uptake of carbonyl-containing volatile organic compounds (cVOCs) by aqueous atmospheric aerosols is a likely source of particulate organic material. The aqueous-phase secondary organic products of some cVOCs are surface-active. Therefore, cVOC uptake can lead to organic film formation at the gas-aerosol interface and changes in aerosol surface tension. We examined the chemical reactions of two abundant cVOCs, formaldehyde and acetaldehyde, in water and aqueous ammonium sulfate (AS) solutions mimicking tropospheric aerosols. Secondary organic products were identified using Aerosol Chemical Ionization Mass Spectrometry (Aerosol-CIMS), and changes in surface tension were monitored using pendant drop tensiometry. Hemiacetal oligomers and aldol condensation products were identified using Aerosol-CIMS. A hemiacetal sulfate ester was tentatively identified in the formaldehyde-AS system. Acetaldehyde depresses surface tension to 65(\\pm2) dyn/cm in pure water and 62(\\pm1) dyn/cm in AS solutions. Surface t...

  5. Reactive processing of formaldehyde and acetaldehyde in aqueous aerosol mimics: surface tension depression and secondary organic products

    Directory of Open Access Journals (Sweden)

    Z. Li

    2011-07-01

    Full Text Available The reactive uptake of carbonyl-containing volatile organic compounds (cVOCs by aqueous atmospheric aerosols is a likely source of particulate organic material. The aqueous-phase secondary organic products of some cVOCs are surface-active. Therefore, cVOC uptake can lead to organic film formation at the gas-aerosol interface and changes in aerosol surface tension. We examined the chemical reactions of two abundant cVOCs, formaldehyde and acetaldehyde, in water and aqueous ammonium sulfate (AS solutions mimicking tropospheric aerosols. Secondary organic products were identified using Aerosol Chemical Ionization Mass Spectrometry (Aerosol-CIMS, and changes in surface tension were monitored using pendant drop tensiometry. Hemiacetal oligomers and aldol condensation products were identified using Aerosol-CIMS. A hemiacetal sulfate ester was tentatively identified in the formaldehyde-AS system. Acetaldehyde depresses surface tension to 65(±2 dyn cm−1 in pure water and 62(±1 dyn cm−1 in AS solutions. Surface tension depression by formaldehyde in pure water is negligible; in AS solutions, a 9 % reduction in surface tension is observed. Mixtures of these species were also studied in combination with methylglyoxal in order to evaluate the influence of cross-reactions on surface tension depression and product formation in these systems. We find that surface tension depression in the solutions containing mixed cVOCs exceeds that predicted by an additive model based on the single-species isotherms.

  6. Catalytic Upgrading of Biomass-Derived Compounds via C-C Coupling Reactions. Computational and Experimental Studies of Acetaldehyde and Furan Reactions in HZSM-5

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Cong [Argonne National Lab. (ANL), Argonne, IL (United States); Evans, Tabitha J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Cheng, Lei [Argonne National Lab. (ANL), Argonne, IL (United States); Nimlos, Mark R. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mukarakate, Calvin [National Renewable Energy Lab. (NREL), Golden, CO (United States); Robichaud, David J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Assary, Rajeev S. [Argonne National Lab. (ANL), Argonne, IL (United States); Curtiss, Larry A. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-10-02

    These catalytic C–C coupling and deoxygenation reactions are essential for upgrading of biomass-derived oxygenates to fuel-range hydrocarbons. Detailed understanding of mechanistic and energetic aspects of these reactions is crucial to enabling and improving the catalytic upgrading of small oxygenates to useful chemicals and fuels. Using periodic density functional theory (DFT) calculations, we have investigated the reactions of furan and acetaldehyde in an HZSM-5 zeolite catalyst, a representative system associated with the catalytic upgrading of pyrolysis vapors. Comprehensive energy profiles were computed for self-reactions (i.e., acetaldehyde coupling and furan coupling) and cross-reactions (i.e., acetaldehyde + furan) of this representative mixture. Major products proposed from the computations are further confirmed using temperature controlled mass spectra measurements. Moreover, the computational results show that furan interacts with acetaldehyde in HZSM-5 via an alkylation mechanism, which is more favorable than the self-reactions, indicating that mixing furans with aldehydes could be a promising approach to maximize effective C–C coupling and dehydration while reducing the catalyst deactivation (e.g., coke formation) from aldehyde condensation.

  7. One-Pot Synthesis of (S)-Baclofen via Aldol Condensation of Acetaldehyde with Diphenylprolinol Silyl Ether Mediated Asymmetric Michael Reaction as a Key Step.

    Science.gov (United States)

    Hayashi, Yujiro; Sakamoto, Daisuke; Okamura, Daichi

    2016-01-01

    An efficient asymmetric total synthesis of (S)-baclofen was accomplished via a one-pot operation from commercially available materials using sequential reactions, such as aldol condensation of acetaldehyde, diphenylprolinol silyl ether mediated asymmetric Michael reaction of nitromethane, Kraus-Pinnick oxidation, and Raney Ni reduction. Highly enantioenriched baclofen was obtained in one pot with a good yield over four reactions. PMID:26636719

  8. Phytophenols in whisky lower blood acetaldehyde level by depressing alcohol metabolism through inhibition of alcohol dehydrogenase 1 (class I) in mice.

    Science.gov (United States)

    Haseba, Takeshi; Sugimoto, Junichi; Sato, Shigeo; Abe, Yuko; Ohno, Youkichi

    2008-12-01

    We recently reported that the maturation of whisky prolongs the exposure of the body to a given dose of alcohol by reducing the rate of alcohol metabolism and thus lowers the blood acetaldehyde level (Alcohol Clin Exp Res. 2007;31:77s-82s). In this study, administration of the nonvolatile fraction of whisky was found to lower the concentration of acetaldehyde in the blood of mice by depressing alcohol metabolism through the inhibition of liver alcohol dehydrogenase (ADH). Four of the 12 phenolic compounds detected in the nonvolatile fraction (caffeic acid, vanillin, syringaldehyde, ellagic acid), the amounts of which increase during the maturation of whisky, were found to strongly inhibit mouse ADH 1 (class I). Their inhibition constant values for ADH 1 were 0.08, 7.9, 15.6, and 22.0 mumol/L, respectively, whereas that for pyrazole, a well-known ADH inhibitor, was 5.1 mumol/L. The 2 phenolic aldehydes and ellagic acid exhibited a mixed type of inhibition, whereas caffeic acid showed the competitive type. When individually administered to mice together with ethanol, each of these phytophenols depressed the elimination of ethanol, thereby lowering the acetaldehyde concentration of blood. Thus, it was demonstrated that the enhanced inhibition of liver ADH 1 due to the increased amounts of these phytophenols in mature whisky caused the depression of alcohol metabolism and a consequent lowering of blood acetaldehyde level. These substances are commonly found in various food plants and act as antioxidants and/or anticarcinogens. Therefore, the intake of foods rich in them together with alcohol may not only diminish the metabolic toxicity of alcohol by reducing both the blood acetaldehyde level and oxidative stress, but also help limit the amount of alcohol a person drinks by depressing alcohol metabolism.

  9. Reactive processing of formaldehyde and acetaldehyde in aqueous aerosol mimics: surface tension depression and secondary organic products

    Directory of Open Access Journals (Sweden)

    Z. Li

    2011-11-01

    Full Text Available The reactive uptake of carbonyl-containing volatile organic compounds (cVOCs by aqueous atmospheric aerosols is a likely source of particulate organic material. The aqueous-phase secondary organic products of some cVOCs are surface-active. Therefore, cVOC uptake can lead to organic film formation at the gas-aerosol interface and changes in aerosol surface tension. We examined the chemical reactions of two abundant cVOCs, formaldehyde and acetaldehyde, in water and aqueous ammonium sulfate (AS solutions mimicking tropospheric aerosols. Secondary organic products were identified using Aerosol Chemical Ionization Mass Spectrometry (Aerosol-CIMS, and changes in surface tension were monitored using pendant drop tensiometry. Hemiacetal oligomers and aldol condensation products were identified using Aerosol-CIMS. Acetaldehyde depresses surface tension to 65(±2 dyn cm−1 in pure water (a 10% surface tension reduction from that of pure water and 62(±1 dyn cm−1 in AS solutions (a 20.6% reduction from that of a 3.1 M AS solution. Surface tension depression by formaldehyde in pure water is negligible; in AS solutions, a 9% reduction in surface tension is observed. Mixtures of these species were also studied in combination with methylglyoxal in order to evaluate the influence of cross-reactions on surface tension depression and product formation in these systems. We find that surface tension depression in the solutions containing mixed cVOCs exceeds that predicted by an additive model based on the single-species isotherms.

  10. Peracetic Acid Synthesis by Acetaldehyde Liquid Phase Oxidation in Trickle Bed Reactor%滴流床中乙醛液相氧化合成过氧乙酸新工艺

    Institute of Scientific and Technical Information of China (English)

    张腾云; 罗京莉; K.Chuang; 钟理

    2007-01-01

    In this paper, shorter residence time (a few minutes) with high yield in the trickle bed process for peracetic acid synthesis by acetaldehyde liquid phase oxidation can be realized on the selected packing material SA-5118.For acetaldehyde in acetone with ferric ion as catalyst, the optimized process conditions were presented.The main factors influencing the yield, selectivity and conversion are residence time, temperature and acetaldehyde concentration, respectively.The temperature range checked is from 30 to 65℃.High yield of 81.53% with high selectivity of 91.84% can be obtained at higher temperature of 55℃ when the residence time is 5.5min and the acetaldehyde concentration is 9.85% (by mass).And there is a critical acetaldehyde concentration point (Cccp) between 18% and 19.5% (by mass).At temperature less than 55℃, the highest yield to peracetic acid at each temperature level increases with temperature when the acetaldehyde concentration is below Cccp and decreases with temperature when the acetaldehyde concentration is above Cccoy.

  11. Formation of the thioester, N,S-diacetylcysteine, from acetaldehyde and N,N'diacetylcystine in aqueous solution with ultraviolet light

    Energy Technology Data Exchange (ETDEWEB)

    Weber, A.L.

    1981-05-01

    The thioester, N,S-diacetylcysteine, is formed during the illumination of phosphate buffered (pH 7.0) aqueous solutions of acetaldehyde and N,N'-diacetylcystine with ultraviolet light. The yield of N,S-diacetylcysteine relative to N-acetylcysteine and unidentified products progressively increases as ultraviolet light below 239 nm, 253 nm and 281 nm is cut off with optical filters. When ultraviolet light below 320 nm is removed with an optical filter, there is no detectable reaction. Illumination of 0.025 M N,N'-diacetylcystine with 0.5 M and 1.0 M acetaldehyde with filtered ultraviolet light gives, respectively, 20% and 80% yields of N,S-diacetylcysteine. In the reaction with 1.0 M acetyldehyde, N-acetylcysteine forms early in the reaction and later decreases with its conversion to N,S-diacetylcysteine. The prebiotic significance of these reactions is discussed.

  12. Formation of the thioester, N,S-diacetylcysteine, from acetaldehyde and N,N'diacetylcystine in aqueous solution with ultraviolet light

    International Nuclear Information System (INIS)

    The thioester, N,S-diacetylcysteine, is formed during the illumination of phosphate buffered (pH 7.0) aqueous solutions of acetaldehyde and N,N'-diacetylcystine with ultraviolet light. The yield of N,S-diacetylcysteine relative to N-acetylcysteine and unidentified products progressively increases as ultraviolet light below 239 nm, 253 nm and 281 nm is cut off with optical filters. When ultraviolet light below 320 nm is removed with an optical filter, there is no detectable reaction. Illumination of 0.025 M N,N'-diacetylcystine with 0.5 M and 1.0 M acetaldehyde with filtered ultraviolet light gives, respectively, 20% and 80% yields of N,S-diacetylcysteine. In the reaction with 1.0 M acetyldehyde, N-acetylcysteine forms early in the reaction and later decreases with its conversion to N,S-diacetylcysteine. The prebiotic significance of these reactions is discussed. (orig.)

  13. Visible-light photodecomposition of acetaldehyde by TiO2-coated gold nanocages: plasmon-mediated hot electron transport via defect states.

    Science.gov (United States)

    Kodiyath, Rajesh; Manikandan, Maidhily; Liu, Lequan; Ramesh, Gubbala V; Koyasu, Satoshi; Miyauchi, Masahiro; Sakuma, Yoshiki; Tanabe, Toyokazu; Gunji, Takao; Duy Dao, Thang; Ueda, Shigenori; Nagao, Tadaaki; Ye, Jinhua; Abe, Hideki

    2014-12-21

    Skeletal gold nanocages (Au NCs) are synthesized and coated with TiO2 layers (TiO2-Au NCs). The TiO2-Au NCs exhibit enhanced photodecomposition activity toward acetaldehyde under visible light (>400 nm) illumination because hot electrons are generated over the Au NCs by local surface plasmon resonance (LSPR) and efficiently transported across the metal/semiconductor interface via the defect states of TiO2. PMID:25357137

  14. Density Functional Theory Study on Mechanism of Forming Spiro-Ge-heterocyclic Ring Compound from Me2Ge=Ge: and Acetaldehyde

    Institute of Scientific and Technical Information of China (English)

    Xiu-hui Lu; Yong-qing Li; Wei-jie Bao; Dong-ting Liu

    2013-01-01

    The H2Ge=Ge:,as well as and its derivatives (X2Ge=Ge:,X=H,Me,F,CI,Br,Ph,Ar,...)is a kind of new species.Its cycloaddition reactions is a new area for the study of germylene chemistry.The mechanism of the cycloaddition reaction between singlet Me2Ge=Ge:and acetaldehyde was investigated with the B3LYP/6-31G* method in this work.From the potential energy profile,it could be predicted that the reaction has one dominant reaction pathway.The reaction rule is that the two reactants firstly form a four-membered Ge-heterocyclic ring germylene through the [2+2] cycloaddition reaction.Because of the 4p unoccupied orbital of Ge:atom in the four-membered Ge-heterocyclic ring germylene and the π orbital of acetaldehyde forning a π-p donor-acceptor bond,the four-membered Ge-heterocyclic ring germylene further combines with acetaldehyde to form an intermediate.Because the Ge atom in intermediate happens sp3 hybridization after transition state,then,intermediate isomerizes to a spiro-Ge-heterocyclic ring compound via a transition state.The research result indicates the laws of cycloaddition reaction between Me2Ge=Ge:and acetaldehyde,and lays the theory foundation of the cycloaddition reaction between H2Ge=Ge:and its derivatives (X2Ge=Ge:,X=H,Me,F,Cl,Br,Ph,Ar) and asymmetric π-bonded compounds,which are significant for the synthesis of small-ring and spiro-Ge-heterocyclic ring compounds.

  15. Mechanistic insights into the formation of acetaldehyde and diethyl ether from ethanol over supported VO{subx}, MoO{subx}, and WO{subx} catalysts.

    Energy Technology Data Exchange (ETDEWEB)

    Nair, H.; Gatt, J. E.; Miller, J. T.; Baertsch, C. D. (Chemical Sciences and Engineering Division); (Purdue University)

    2011-04-01

    Catalytic pathways are described for reactions of ethanol to acetaldehyde by oxidative dehydrogenation and of ethanol to diethyl ether by condensation over VO{sub x}-Al{sub 2}O{sub 3}, MoO{sub x}-Al{sub 2}O{sub 3}, and WO{sub x}-Al{sub 2}O{sub 3}. Isotopic labeling shows that acetaldehyde formation occurs via rate-determining C-H bond cleavage of the CH{sub 2} group in an adsorbed alkoxide followed by removal of surface oxygen in a Mars and van Krevelen redox mechanism (as confirmed by in situ X-ray absorption, diffuse reflectance infra-red Fourier transform spectroscopy and UV-visible spectroscopy); diethyl ether formation occurs in parallel via coupling and condensation of two adjacent ethoxy species. Using a combination of in situ spectroscopic and kinetic analysis, catalyst properties influencing the formation of acetaldehyde and ether from the common adsorbed ethoxy intermediate are elucidated. X-ray absorption analysis during anaerobic ethanol titration is used to preclude the involvement of terminal M{double_bond}O bonds during the reaction. A study of the activity of catalysts with the same MoO{sub x} domain size on Al{sub 2}O{sub 3}, TiO{sub 2}, and CeO{sub 2} supports and binary oxides of MoO{sub x} and WO{sub x} on Al{sub 2}O{sub 3} are used to prove that the active redox oxygen for acetaldehyde formation is the oxygen atom linking the active metal oxide domain to the support oxide. Ether formation ability of the metal oxide is related to the electronegativity of the active metal atom.

  16. Efficient expression of codon-adapted human acetaldehyde dehydrogenase 2 cDNA with 6×His tag in Pichia pastoris

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Human mitochondrial acetaldehyde dehydrogenase 2 (ALDH2) catalyzes the oxidation of acetaldehyde to acetic acid. Therefore, ALDH2 has therapeutic potential in detoxification of acetaldehyde. Further-more, ALDH2 catalyzes nitroglycerin to nitrate and 1, 2-glyceryldinitrate during therapy for angina pectoris, myocardial infarction, and heart failure. Large quantities of ALDH2 will be needed for potential clinical practice. In this study, Pichia pastoris was used as a platform for expression of human ALDH2. Based on the ALDH2*1 cDNA sequence, we designed ALDH2 cDNA by choosing the P. pastoris preferred codons and by decreasing the G + C content level. The sequence was synthesized using the overlap extension PCR method. The cDNA and 6×His tags were subcloned into the plasmid pPIC9K. The recombinant protein was expressed in P. pastoris GS115 and purified using Ni2+-Sepharose affinity chromatography. The amount of secreted protein in the culture was 80 mg/L in shake-flask cultivation and 260 mg/L in high-density bioreactor fermentation. Secreted ALDH2 was easily purified from the culture supernatant by using Ni2+-Sepharose affinity chromatography. After purification of the fermentation supernatant, the enzyme had a specific activity of 1.2 U/mg protein. The yield was about 16 mg/L in a shake flask culture of P. pastoris GS115 which contained the original human ALDH2*1 cDNA.

  17. Simultaneous removal of ethanol,acetaldehyde and nitrogen oxides over V-Pd/γ-Al2O3-TiO2 catalyst

    Institute of Scientific and Technical Information of China (English)

    Zhe Li; Jing Wang; Kai He; Xia An; Wei Huang; Kechang Xie

    2011-01-01

    V-Pd/γ-Al2O3-TiO2 catalysts with different vanadium contents were prepared by a combined sol-gel and impregnation method.X-ray diffraction(XRD),N2 adsorption-desorption(BET),X-ray photoelectron spectroscopy(XPS)and catalytic removal of ethanol,acetaldehyde and nitrogen oxides at low temperature(<300℃)were used to assess the properties of the catalysts.The results showed that the sample with 1wt% vanadium exhibited an excellent catalytic performance for simultaneous removal of ethanol,acetaldehyde and nitrogen oxides.The conversions of ethanol,acetaldehyde and nitrogen oxides at 250℃ were 100%,74.4% and 98.7%,respectively.V-Pd/γ-Al2O3-TiO2 catalyst with 1 wt% vanadium showed the largest surface area and higher dispersion of vanadium oxide on the catalyst surface,and possessed a larger mole fraction of V4+species and unique PdO species on the surface,which can be attributed to the strong synergistic effect among palladium,vanadium and the carriers.The higher activity of V-Pd/γ-Al2O3-TiO2 catalyst is related to the V4+and Pd2+species on the surface,which might be favorable for the formation of active sites.

  18. Acetaldehyde partial oxidation on the Au(111) model catalyst surface: C-C bond activation and formation of methyl acetate as an oxidative coupling product

    Science.gov (United States)

    Karatok, Mustafa; Vovk, Evgeny I.; Shah, Asad A.; Turksoy, Abdurrahman; Ozensoy, Emrah

    2015-11-01

    Partial oxidation of acetaldehyde (CH3CHO) on the oxygen pre-covered Au(111) single crystal model catalyst was investigated via Temperature Programmed Desorption (TPD) and Temperature Programmed Reaction Spectroscopy (TPRS) techniques, where ozone (O3) was utilized as the oxygen delivery agent providing atomic oxygen to the reacting surface. We show that for low exposures of O3 and small surface oxygen coverages, two partial oxidation products namely, methyl acetate (CH3COOCH3) and acetic acid (CH3COOH) can be generated without the formation of significant quantities of carbon dioxide. The formation of methyl acetate as the oxidative coupling reaction product implies that oxygen pre-covered Au(111) single crystal model catalyst surface can activate C-C bonds. In addition to the generation of these products; indications of the polymerization of acetaldehyde on the gold surface were also observed as an additional reaction route competing with the partial and total oxidation pathways. The interplay between the partial oxidation, total oxidation and polymerization pathways reveals the complex catalytic chemistry associated with the interaction between the acetaldehyde and atomic oxygen on catalytic gold surfaces.

  19. Electron spin resonance study of free radicals produced from ethanol and acetaldehyde after exposure to a Fenton system or to brain and liver microsomes

    Energy Technology Data Exchange (ETDEWEB)

    Gonthier, B.; Jeunet, A.; Barret, L. (Departement de Toxicologie, C.H.R.U. de Grenoble, (France))

    1991-09-01

    Free radical formation from ethanol and acetaldehyde was studied in the presence of a spin-trap and a NADPH generating system with a chemical model, Fenton's reagent, or by enzymatic oxidation of these solvents by rat liver and brain microsomes. The free radicals were detected by electron spin resonance spectroscopy (E.S.R.), using the spin-trapping agent, alpha-(4-pyridyl l-oxide)-N-tertbutyl-nitrone (POBN). Under such conditions, the hydroxyethyl radical derived from ethanol was obtained after both incubation in liver and brain microsomes as well as after exposure to the Fenton system. Enzymatic inhibition and activation showed that the mixed function oxidase system plays an important role in the generation of such a radical, even in the brain. Under all the experimental conditions acetaldehyde could also generate a free radical deriving directly from the parent molecule and modified by enzymatic activation or inhibition. A second, longer lasting radical was also observed in the presence of acetaldehyde. On the basis of a comparative study to a known process causing lipoperoxidation, its lipidic origin was suggested.

  20. Efficient expression of codon-adapted human acetaldehyde dehydrogenase 2 cDNA with 6×His tag in Pichia pastoris

    Institute of Scientific and Technical Information of China (English)

    ZHAO YuFeng; LEI MingKe; WU YuanXin; ZHANG ZiSheng; WANG CunWen

    2009-01-01

    Human mitochondrial acetaldehyde dehydrogenase 2 (ALDH2) catalyzes the oxidation of acetaldehyde to acetic acid. Therefore, ALDH2 has therapeutic potential in detoxification of acetaldehyde. Furthermore, ALDH2 catalyzes nitroglycerin to nitrate and 1, 2-glyceryldinitrate during therapy for angina pectoris, myocardial infarction, and heart failure. Large quantities of ALDH2 will be needed for potential clinical practice. In this study, Pichia pastoris was used as a platform for expression of human ALDH2.Based on the ALDH2~*1 cDNA sequence, we designed ALDH2 cDNA by choosing the P. pastoris preferred codons and by decreasing the G + C content level. The sequence was synthesized using the overlap extension PCR method. The cDNA and 6×His tags were subcloned into the plasmid pPIC9K.The recombinant protein was expressed in P. pastoris GS115 and purified using Ni~(2+)-Sepharose affinity chromatography. The amount of secreted protein in the culture was 80 mg/L in shake-flask cultivation and 260 mglL in high-density bioreactor fermentation. Secreted ALDH2 was easily purified from the culture supernatant by using Ni2+-Sepharose affinity chromatography. After purification of the fermentation supernatant, the enzyme had a specific activity of 1.2 U/mg protein. The yield was about 16 mg/L in a shake flask culture of P. pastoris GS115 which contained the original human ALDH2~*1 cDNA.

  1. Concerns regarding 24-h sampling for formaldehyde, acetaldehyde, and acrolein using 2,4-dinitrophenylhydrazine (DNPH)-coated solid sorbents

    Science.gov (United States)

    Herrington, Jason S.; Hays, Michael D.

    2012-08-01

    There is high demand for accurate and reliable airborne carbonyl measurement methods due to the human and environmental health impacts of carbonyls and their effects on atmospheric chemistry. Standardized 2,4-dinitrophenylhydrazine (DNPH)-based sampling methods are frequently applied for measuring gaseous carbonyls in the atmospheric environment. However, there are multiple short-comings associated with these methods that detract from an accurate understanding of carbonyl-related exposure, health effects, and atmospheric chemistry. The purpose of this brief technical communication is to highlight these method challenges and their influence on national ambient monitoring networks, and to provide a logical path forward for accurate carbonyl measurement. This manuscript focuses on three specific carbonyl compounds of high toxicological interest—formaldehyde, acetaldehyde, and acrolein. Further method testing and development, the revision of standardized methods, and the plausibility of introducing novel technology for these carbonyls are considered elements of the path forward. The consolidation of this information is important because it seems clear that carbonyl data produced utilizing DNPH-based methods are being reported without acknowledgment of the method short-comings or how to best address them.

  2. Acetaldehyde metabolism by liver mitochondrial ALDH from UChA and UChB rats: effect of inhibitors.

    Science.gov (United States)

    Tampier, L; Sánchez, E; Quintanilla, M E

    1996-01-01

    We have observed that blood acetaldehyde (AcH) levels after an ethanol dose were significantly higher in disulfiram-pre-treated UChA (low ethanol consumer) than in UChB (high ethanol consumer) rats. In order to explore these results further, we studied the effect of disulfiram (300 mg/kg i.p.) and chlorpropamide (80) mg/kg i.p.) pre-treatment on blood AcH levels after oral ethanol (60 mmol/kg) and on AcH metabolism by liver mitochondrial aldehyde(s) dehydrogenase(s) from UChA and UChB rats. AcH metabolism by liver mitochondrial aldehyde dehydrogenase (ALDH) was studied by following AcH disappearance rate and the formation of NADH at 340 nm in the incubation medium. The results showed that chlorpropamide, like disulfiram, produced a higher blood AcH level consistent with a greater inhibition of the low-Km mitochondrial ALDH in the UChA rats than in the UChB rats. These drugs did not inhibit the high Km mitochondrial ALDH. Kinetic studies of mitochondrial ALDH show that low-Km mitochondrial ALDH from UChB rats exhibits a higher affinity for NAD than UChA rats. This observation could explain the different inhibition of ALDH by both drugs, assuming that the inhibitors reduce NAD availability, the rate limiting step in the mitochondrial ALDH oxidation.

  3. Effect of acid catalysts and accelerated aging on the reaction of methanol with hydroxy-acetaldehyde in bio-oil

    Directory of Open Access Journals (Sweden)

    Bhattacharya, P.

    2010-05-01

    Full Text Available Bio-oil is a promising alternative source of energy produced from fast pyrolysis of biomass. Increasing the viscosity of bio-oil during storage is a major problem that can be controlled by the addition of methanol or other alcohols. This paper reports the results of our investigation of the reactions of short chain alcohols with aldehydes and acids in bio-oil. The reaction of methanol with hydroxyacetaldehyde (HA to form the acetal was catalyzed by the addition of 7 x 10-4 M strong acids such as sulfuric, hydrochloric, p-toluene sulfonic acid, and methanesulfonic acid. HA formed 2,2-dimethoxyethanol (DME, and at 60 oC the equilibrium was reached in less than one hour. Smaller amounts of DME were formed in the absence of strong acid. HA, acetaldehyde, and propanal formed their corresponding acetals when reacted with methanol, ethanol, 1-propanol or 1-butanol. Esters of acetic acid and hydroxyacetic acid were observed from reactions with these same four alcohols. Other acetals and esters were observed by GC/MS analysis of the reaction products. The results from accelerated aging experiments at 90 oC suggest that the presence of methanol slows polymerization by formation of acetals and esters from low molecular weight aldehydes and organic acids.

  4. Formaldehyde and acetaldehyde exposure mitigation in US residences: In-home measurements of ventilation control and source control

    Energy Technology Data Exchange (ETDEWEB)

    Hult, Erin L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Willem, Henry [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Price, Phillip N. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hotchi, Toshifumi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Russell, Marion L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-10-01

    Measurements were taken in new US residences to assess the extent to which ventilation and source control can mitigate formaldehyde exposure. Increasing ventilation consistently lowered indoor formaldehyde concentrations. However, at a reference air exchange rate of 0.35 h-1, increasing ventilation was up to 60% less effective than would be predicted if the emission rate were constant. This is consistent with formaldehyde emission rates decreasing as air concentrations increase, as observed in chamber studies. In contrast, measurements suggest acetaldehyde emission was independent of ventilation rate. To evaluate the effectiveness of source control, formaldehyde concentrations were measured in Leadership in Energy and Environmental Design (LEED) certified/Indoor airPLUS homes constructed with materials certified to have low emission rates of volatile organic compounds (VOC). At a reference air exchange rate of 0.35 h-1, and adjusting for home age, temperature and relative humidity, formaldehyde concentrations in homes built with low-VOC materials were 42% lower on average than in reference new homes with conventional building materials. Without adjustment, concentrations were 27% lower in the low-VOC homes. The mean and standard deviation of formaldehyde concentration were 33 μg m-3 and 22 μg m-3 for low-VOC homes and 45 μg m-3 and 30 μg m-3 for conventional.

  5. Mechanisms of action of acetaldehyde in the up-regulation of the human α2(I) collagen gene in hepatic stellate cells: key roles of Ski, SMAD3, SMAD4, and SMAD7.

    Science.gov (United States)

    Reyes-Gordillo, Karina; Shah, Ruchi; Arellanes-Robledo, Jaime; Hernández-Nazara, Zamira; Rincón-Sánchez, Ana Rosa; Inagaki, Yutaka; Rojkind, Marcos; Lakshman, M Raj

    2014-05-01

    Alcohol-induced liver fibrosis and eventually cirrhosis is a leading cause of death. Acetaldehyde, the first metabolite of ethanol, up-regulates expression of the human α2(I) collagen gene (COL1A2). Early acetaldehyde-mediated effects involve phosphorylation and nuclear translocation of SMAD3/4-containing complexes that bind to COL1A2 promoter to induce fibrogenesis. We used human and mouse hepatic stellate cells to elucidate the mechanisms whereby acetaldehyde up-regulates COL1A2 by modulating the role of Ski and the expression of SMADs 3, 4, and 7. Acetaldehyde induced up-regulation of COL1A2 by 3.5-fold, with concomitant increases in the mRNA (threefold) and protein (4.2- and 3.5-fold) levels of SMAD3 and SMAD4, respectively. It also caused a 60% decrease in SMAD7 expression. Ski, a member of the Ski/Sno oncogene family, is colocalized in the nucleus with SMAD4. Acetaldehyde induces translocation of Ski and SMAD4 to the cytoplasm, where Ski undergoes proteasomal degradation, as confirmed by the ability of the proteasomal inhibitor lactacystin to blunt up-regulation of acetaldehyde-dependent COL1A2, but not of the nonspecific fibronectin gene (FN1). We conclude that acetaldehyde up-regulates COL1A2 by enhancing expression of the transactivators SMAD3 and SMAD4 while inhibiting the repressor SMAD7, along with promoting Ski translocation from the nucleus to cytoplasm. We speculate that drugs that prevent proteasomal degradation of repressors targeting COL1A2 may have antifibrogenic properties.

  6. Acetaldehyde as a drug of abuse: insight into AM281 administration on operant-conflict paradigm in rats.

    Directory of Open Access Journals (Sweden)

    Fulvio ePlescia

    2013-06-01

    Full Text Available Increasing evidence focuses on acetaldehyde (ACD as the mediator of the rewarding and motivational properties of ethanol. Indeed, ACD stimulates dopamine release in the nucleus accumbens and it is self-administered under different conditions. Besides the dopaminergic transmission, the endocannabinoid system has been reported to play an important role in ethanol central effects, modulating primary alcohol rewarding effect, drug-seeking and relapse behaviour. Drug motivational properties are highlighted in operant paradigms which include response-contingent punishment, a behavioural equivalent of compulsive drug use despite adverse consequences.The aim of this study was thus to characterize ACD motivational and rewarding properties employing an operant-conflict paradigm in which rats, trained to lever press in order to get ACD solution (0.9%, undergo extinction, reinstatement and conflict sessions, according to a modified Geller-Seifter procedur. Furthermore the role played by CB1 receptor system in modulating ACD-induced effects were investigated through the administration of CB1 receptor antagonist, AM281 (1 mg/kg, i.p. during the extinction-, relapse- and conflict experiments.Our results indicate that ACD is able to induce and maintain an operant behaviour, a high number of responses during extinction, an increase in the lever presses during the reinstatement phase, and a higher emission of punished responses during the conflict experiments, when compared to controls.The administration of AM281 is able to decrease ACD-seeking behaviour during extinction, the number of lever presses during reinstatement and to strongly decrease the punished responses for ACD. Our data strengthen the idea that ACD may be responsible for the central effects of ethanol, and pinpoint at the CB1 system as one of the neural substrates underlying its addictive properties.

  7. Ethanol and acetaldehyde differentially alter extracellular dopamine and serotonin in Aldh2-knockout mouse dorsal striatum: A reverse microdialysis study.

    Science.gov (United States)

    Jamal, Mostofa; Ameno, Kiyoshi; Miki, Takanori; Tanaka, Naoko; Ito, Asuka; Ono, Junichiro; Takakura, Ayaka; Kumihashi, Mitsuru; Kinoshita, Hiroshi

    2016-01-01

    Dopamine (DA) and serotonin (5-HT) seem to be involved in several of the effects of ethanol (EtOH). Acetaldehyde (AcH), especially in the brain, induces effects that mimic those of EtOH. The purpose of this study was to investigate the effects of local perfusion of EtOH and AcH on extracellular DA and 5-HT in the dorsal striatum of Aldh2-knockout (Aldh2-KO) and wild-type (WT) mice. Aldh2-KO mice were used as a model of aldehyde dehydrogenase 2 deficiency in humans to examine the effects of AcH. Mice were perfused with Ringer's solution (control), EtOH (100, 200, or 500mM) and AcH (100, 200, or 500μM) into the dorsal striatum. Dialysate samples were collected every 5min, and then analyzed with HPLC coupled to an ECD. We found that local perfusion with 500mM EtOH increased extracellular levels of DA (p<0.05) in both Aldh2-KO and WT mice, while 5-HT levels remain unchanged. EtOH at a dose of 200mM also increased DA in WT mice, but this was limited to a 30-40-min time-point. In contrast, perfusion with 200 and 500μM AcH decreased both DA and 5-HT (p<0.05) in Aldh2-KO mice, but this decrease was not found in WT mice at any AcH dose, indicating an effect of AcH on DA and 5-HT levels. There were no genotype effects on the basal levels of DA and 5-HT. These results indicate that high EtOH can stimulate DA, whereas high AcH can depress both DA and 5-HT in the dorsal striatum of mice. PMID:26711020

  8. Effect of diet and disulfiram on acetaldehyde blood levels after ethanol in UChA and UChB rats.

    Science.gov (United States)

    Quintanilla, M E; Sepúlveda, S; Tampier, L

    1993-01-01

    Acetaldehyde (AcH) levels in blood samples taken from different zones of the vascular system 2 h after a p.o. dose of ethanol (2.76 g/kg) were studied in UChA (low ethanol consumer) and UChB (high ethanol consumer) rats fed a diet devoid of animal products, diet 1 (D1), and a diet containing fish meal, diet 2 (D2), and in rats pretreated with disulfiram (600 mg/kg p.o.). The results showed that, while there is no significant difference between UChA and UChB rats fed D1 with respect to blood AcH levels and the basal activity of the hepatic mitochondrial high-affinity aldehyde dehydrogenase (AIDH), a significant strain difference was observed in rats fed D2, which induced high blood AcH levels in UChA rats but not in UChB ones. No strain differences were observed in blood ethanol levels in the two groups of rats. When rats fed D1 were pretreated with disulfiram, the raising of AcH blood levels induced by ethanol after disulfiram was significantly higher in UChA than in UChB rats in suprahepatic vein, femoral vein, and tail blood. This difference was concomitant with a greater inhibition of the hepatic mitochondrial high-affinity ADH activity in UChA rats than in UChB ones, whether disulfiram was administered in vivo or in vitro, which excluded the possibility that the strain difference would be caused by a different bioavailability of disulfiram.

  9. Acetaldehyde as a drug of abuse: insight into AM281 administration on operant-conflict paradigm in rats.

    Science.gov (United States)

    Plescia, Fulvio; Brancato, Anna; Marino, Rosa A M; Cannizzaro, Carla

    2013-01-01

    Increasing evidence focuses on acetaldehyde (ACD) as the mediator of the rewarding and motivational properties of ethanol. Indeed, ACD stimulates dopamine release in the nucleus accumbens and it is self-administered under different conditions. Besides the dopaminergic transmission, the endocannabinoid system has been reported to play an important role in ethanol central effects, modulating primary alcohol rewarding effect, drug-seeking, and relapse behavior. Drug motivational properties are highlighted in operant paradigms which include response-contingent punishment, a behavioral equivalent of compulsive drug use despite adverse consequences. The aim of this study was thus to characterize ACD motivational and rewarding properties employing an operant-conflict paradigm in which rats, trained to lever press in order to get ACD solution (0.9%), undergo extinction, reinstatement and conflict sessions, according to a modified Geller-Seifter procedure. Furthermore, the role played by CB1 receptor system in modulating ACD-induced effects were investigated through the administration of CB1 receptor antagonist, AM281 (1 mg/kg, i.p.) during the extinction-, relapse-, and conflict-experiments. Our results indicate that ACD is able to induce and maintain an operant behavior, a high number of responses during extinction, an increase in the lever presses during the reinstatement phase, and a higher emission of punished responses during the conflict experiments, when compared to controls. The administration of AM281 is able to decrease ACD-seeking behavior during extinction, the number of lever presses during reinstatement and to strongly decrease the punished responses for ACD. Our data strengthen the idea that ACD may be responsible for the central effects of ethanol, and pinpoint at the CB1 system as one of the neural substrates underlying its addictive properties.

  10. Acetaldehyde as a drug of abuse: insight into AM281 administration on operant-conflict paradigm in rats.

    Science.gov (United States)

    Plescia, Fulvio; Brancato, Anna; Marino, Rosa A M; Cannizzaro, Carla

    2013-01-01

    Increasing evidence focuses on acetaldehyde (ACD) as the mediator of the rewarding and motivational properties of ethanol. Indeed, ACD stimulates dopamine release in the nucleus accumbens and it is self-administered under different conditions. Besides the dopaminergic transmission, the endocannabinoid system has been reported to play an important role in ethanol central effects, modulating primary alcohol rewarding effect, drug-seeking, and relapse behavior. Drug motivational properties are highlighted in operant paradigms which include response-contingent punishment, a behavioral equivalent of compulsive drug use despite adverse consequences. The aim of this study was thus to characterize ACD motivational and rewarding properties employing an operant-conflict paradigm in which rats, trained to lever press in order to get ACD solution (0.9%), undergo extinction, reinstatement and conflict sessions, according to a modified Geller-Seifter procedure. Furthermore, the role played by CB1 receptor system in modulating ACD-induced effects were investigated through the administration of CB1 receptor antagonist, AM281 (1 mg/kg, i.p.) during the extinction-, relapse-, and conflict-experiments. Our results indicate that ACD is able to induce and maintain an operant behavior, a high number of responses during extinction, an increase in the lever presses during the reinstatement phase, and a higher emission of punished responses during the conflict experiments, when compared to controls. The administration of AM281 is able to decrease ACD-seeking behavior during extinction, the number of lever presses during reinstatement and to strongly decrease the punished responses for ACD. Our data strengthen the idea that ACD may be responsible for the central effects of ethanol, and pinpoint at the CB1 system as one of the neural substrates underlying its addictive properties. PMID:23781180

  11. Catalytic liquid-phase oxidation of acetaldehyde to acetic acid over a Pt/CeO2-ZrO2-SnO2/γ-alumina catalyst.

    Science.gov (United States)

    Choi, Pil-Gyu; Ohno, Takanobu; Masui, Toshiyuki; Imanaka, Nobuhito

    2015-10-01

    Pt/CeO2-ZrO2-SnO2/γ-Al2O3 catalysts were prepared by co-precipitation and wet impregnation methods for catalytic oxidation of acetaldehyde to acetic acid in water. In the present catalysts, Pt and CeO2-ZrO2-SnO2 were successfully dispersed on the γ-Al2O3 support. Dependences of platinum content and reaction time on the selective oxidation of acetaldehyde to acetic acid were investigated to optimize the reaction conditions for obtaining both high acetaldehyde conversion and highest selectivity to acetic acid. Among the catalysts, a Pt(6.4wt.%)/Ce0.68Zr0.17Sn0.15O2.0(16wt.%)/γ-Al2O3 catalyst showed the highest acetaldehyde oxidation activity. On this catalyst, acetaldehyde was completely oxidized after the reaction at 0°C for 8hr, and the selectivity to acetic acid reached to 95% and higher after the reaction for 4hr and longer. PMID:26456607

  12. Caffeine inhibits the activation of hepatic stellate cells induced by acetaldehyde via adenosine A2A receptor mediated by the cAMP/PKA/SRC/ERK1/2/P38 MAPK signal pathway.

    Directory of Open Access Journals (Sweden)

    He Wang

    Full Text Available Hepatic stellate cell (HSC activation is an essential event during alcoholic liver fibrosis. Evidence suggests that adenosine aggravates liver fibrosis via the adenosine A2A receptor (A2AR. Caffeine, which is being widely consumed during daily life, inhibits the action of adenosine. In this study, we attempted to validate the hypothesis that caffeine influences acetaldehyde-induced HSC activation by acting on A2AR. Acetaldehyde at 50, 100, 200, and 400 μM significantly increased HSC-T6 cells proliferation, and cell proliferation reached a maximum at 48 h after exposure to 200 μM acetaldehyde. Caffeine and the A2AR antagonist ZM241385 decreased the cell viability and inhibited the expression of procollagen type I and type III in acetaldehyde-induced HSC-T6 cells. In addition, the inhibitory effect of caffeine on the expression of procollagen type I was regulated by A2AR-mediated signal pathway involving cAMP, PKA, SRC, and ERK1/2. Interestingly, caffeine's inhibitory effect on the expression of procollagen type III may depend upon the A2AR-mediated P38 MAPK-dependent pathway.Caffeine significantly inhibited acetaldehyde-induced HSC-T6 cells activation by distinct A2AR mediated signal pathway via inhibition of cAMP-PKA-SRC-ERK1/2 for procollagen type I and via P38 MAPK for procollagen type III.

  13. Effect of indole-3-carbinol on ethanol-induced liver injury and acetaldehyde-stimulated hepatic stellate cells activation using precision-cut rat liver slices.

    Science.gov (United States)

    Guo, Yu; Wu, Xiao-Qian; Zhang, Chun; Liao, Zhang-Xiu; Wu, Yong; Xia, Zheng-Yuan; Wang, Hui

    2010-12-01

    1. Indole-3-carbinol (I3C), a major indole compound found in high levels in cruciferous vegetables, shows a broad spectrum of biological activities. However, few studies have reported the effect of I3C on alcoholic liver injury. In the present study, we investigated the protective effect of I3C on acute ethanol-induced hepatotoxicity and acetaldehyde-stimulated hepatic stellate cells (HSC) activation using precision-cut liver slices (PCLS). 2. Rat PCLS were incubated with 50 mmol/L ethanol or 350 μmol/L acetaldehyde, and different concentrations (100-400 μmol/L) of I3C were added into the culture system of these two liver injury models, respectively. Hepatotoxicity was assessed by measuring enzyme leakage and malondialdehyde (MDA) content in tissue. Activities of alcoholic enzymes were also determined. α-Smooth muscle actin (α-SMA), transforming growth factor (TGF-β(1) ) and hydroxyproline (HYP) were used as indices to evaluate the activation of HSC. In addition, matrix metalloproteinase-1 (MMP-1) and the tissue inhibitor of metalloproteinase (TIMP-1) were observed to estimate collagen degradation. 3. I3C significantly reduced the enzyme leakage in ethanol-treated slices. In I3C groups, cytochrome P450 (CYP) 2E1 activities were inhibited by 40.9-51.8%, whereas alcohol dehydrogenase (ADH) activity was enhanced 1.6-fold compared with the ethanol-treated group. I3C also showed an inhibitory effect against HSC activation and collagen production stimulated by acetaldehyde. After being incubated with I3C (400 μmol/L), the expression of MMP-1 was markedly enhanced, whereas TIMP-1 was decreased. 4. These results showed that I3C protected PCLS against alcoholic liver injury, which might be associated with the regulation of ethanol metabolic enzymes, attenuation of oxidative injury and acceleration of collagen degradation. PMID:20880187

  14. Quantitative analysis of the lactic acid and acetaldehyde produced by Streptococcus thermophilus and Lactobacillus bulgaricus strains isolated from traditional Turkish yogurts using HPLC.

    Science.gov (United States)

    Gezginc, Y; Topcal, F; Comertpay, S; Akyol, I

    2015-03-01

    The present study was conducted to evaluate the lactic acid- and acetaldehyde-producing abilities of lactic acid bacterial species isolated from traditionally manufactured Turkish yogurts using HPLC. The lactic acid bacterial species purified from the yogurts were the 2 most widely used species in industrial yogurt production: Streptococcus thermophilus and Lactobacillus bulgaricus. These bacteria have the ability to ferment hexose sugars homofermentatively to generate lactic acid and some carbonyl compounds, such as acetaldehyde through pyruvate metabolism. The levels of the compounds produced during fermentation influence the texture and the flavor of the yogurt and are themselves influenced by the chemical composition of the milk, processing conditions, and the metabolic activity of the starter culture. In the study, morphological, biochemical, and molecular characteristics were employed to identify the bacteria obtained from homemade yogurts produced in different regions of Turkey. A collection of 91 Strep. thermophilus and 35 L. bulgaricus strains were investigated for their lactic acid- and acetaldehyde-formation capabilities in various media such as cow milk, LM17 agar, and aerobic-anaerobic SM17 agar or de Man, Rogosa, and Sharpe agar. The amounts of the metabolites generated by each strain in all conditions were quantified by HPLC. The levels were found to vary depending on the species, the strain, and the growth conditions used. Whereas lactic acid production ranged between 0 and 77.9 mg/kg for Strep. thermophilus strains, it ranged from 0 to 103.5 mg/kg for L. bulgaricus. Correspondingly, the ability to generate acetaldehyde ranged from 0 to 105.9 mg/kg in Strep. thermophilus and from 0 to 126.9 mg/kg in L. bulgaricus. Our study constitutes the first attempt to determine characteristics of the wild strains isolated from traditional Turkish yogurts, and the approach presented here, which reveals the differences in metabolite production abilities of the

  15. Ethanol and Acetaldehyde After Intraperitoneal Administration to Aldh2-Knockout Mice-Reflection in Blood and Brain Levels.

    Science.gov (United States)

    Jamal, Mostofa; Ameno, Kiyoshi; Tanaka, Naoko; Ito, Asuka; Takakura, Ayaka; Kumihashi, Mitsuru; Kinoshita, Hiroshi

    2016-05-01

    This paper reports, for the first time, on the analysis of ethanol (EtOH) and acetaldehyde (AcH) concentrations in the blood and brains of Aldh2-knockout (Aldh2-KO) and C57B6/6J (WT) mice. Animals were administrated EtOH (1.0, 2.0 or 4.0 g/kg) or 4-methylpyrazole (4-MP, 82 mg/kg) plus AcH (50, 100 or 200 mg/kg) intraperitoneally. During the blood tests, samples from the orbital sinus of the eye were collected. During the brain tests, dialysates were collected every 5 min (equal to a 15 µl sample) from the striatum using in vivo brain microdialysis. Samples were collected at 5, 10, 15, 20, 25, 30 and 60 min intervals post-EtOH and -AcH injection, and then analyzed by head-space GC. In the EtOH groups, high AcH levels were found in the blood and brains of Aldh2-KO mice, while only small traces of AcH were seen in the blood and brains of WT mice. No significant differences in EtOH levels were observed between the WT and the Aldh2-KO mice for either the EtOH dose. EtOH concentrations in the brain were comparable to the EtOH concentrations in the blood, but the AcH concentrations in the brain were four to five times lower compared to the AcH concentrations in the blood. In the AcH groups, high AcH levels were found in both WT and Aldh2-KO mice. Levels reached a sharp peak at 5 min and then quickly declined for 60 min. Brain AcH concentrations were almost equal to the concentrations found in the blood, where the AcH concentrations were approximately two times higher in the Aldh2-KO mice than in the WT mice, both in the blood and the brain. Our results suggest that systemic EtOH and AcH administration can cause a greater increase in AcH accumulation in the blood and brains of Aldh2-KO mice, where EtOH concentrations in the Aldh2-KO mice were comparable to the EtOH concentrations in the WT mice. Furthermore, detection of EtOH and AcH in the blood and brain was found to be dose-dependent in both genotypes. PMID:26646001

  16. Fructophilic characteristics of Fructobacillus spp. may be due to the absence of an alcohol/acetaldehyde dehydrogenase gene (adhE).

    Science.gov (United States)

    Endo, Akihito; Tanaka, Naoto; Oikawa, Yo; Okada, Sanae; Dicks, Leon

    2014-04-01

    Fructophilic strains of Leuconostoc spp. have recently been reclassified to a new genus, i.e., Fructobacillus. Members of the genus are differentiated from Leuconostoc spp. by their preference for fructose on growth, requirement of an electron acceptor for glucose metabolism, and the inability to produce ethanol from the fermentation of glucose. In the present study, enzyme activities and genes involved in ethanol production were studied, since this is the key pathway for NAD(+)/NADH cycling in heterofermentative lactic acid bacteria. Fructobacillus spp. has a weak alcohol dehydrogenase activity and has no acetaldehyde dehydrogenase activity, whereas both enzymes are active in Leuconostoc mesenteroides. The bifunctional alcohol/acetaldehyde dehydrogenase gene, adhE, was described in Leuconostoc spp., but not in Fructobacillus spp. These results suggested that, due to the deficiency of the adhE gene, the normal pathway for ethanol production is absent in Fructobacillus spp. This leads to a shortage of NAD(+), and the requirement for an electron acceptor in glucose metabolism. Fructophilic characteristics, as observed for Fructobacillus spp., are thus due to the absence of the adhE gene, and a phenotype that most likely evolved as a result of regressive evolution. PMID:24352296

  17. Symthesis of Methyl Hexyl Acetaldehyde by Darzems Reactiom%Darzens 反应合成甲基己基乙醛

    Institute of Scientific and Technical Information of China (English)

    陈文抗

    2014-01-01

    The solvent method for synthesizing methyl hexyl acetaldehyde,under the anhydrous and alkali catalysis,methyl nonyl ketone and α - halogenated acid ester via Darzens reaction to generate α,β - epoxy acid ester,saponification, acidification,heating and decarboxylation. The optimum process conditions acquired:petroleum ether as solvent,reaction temperature for 10 ~ 15℃ for condensation,condensation rate of reached 75% ;25% NaOH solution for saponification;2% sulfuric acidhyl sulfoxide for decarboxylation,the methyl hexyl acetaldehyde must rate reached 61% .%溶剂法缩合制甲基己基乙醛,以甲基壬酮与α-卤代酸酯在无水碱催化下,通过 Darzens 反应生成α,β-环氧酸酯,经皂化、酸化、加热脱羧而得,并对该工艺进行优化,缩合反应以石油醚为溶剂,反应温度为10~15℃,缩合收率达到75%;水解反应:用25%的 NaOH 溶液;脱羧反应:用2%的硫酸,使甲基己基乙醛总收率达到61%。

  18. Analysis of Polymorphic Nanocrystals of TiO2 by X-Ray Rietveld Refinement and High-Resolution Transmission Electron Microscopy: Acetaldehyde Decomposition

    Directory of Open Access Journals (Sweden)

    R. Carrera

    2008-01-01

    Full Text Available In this work, TiO2 nanocrystals were synthesized by the sol-gel method. These materials were annealed at 200 and 500∘C; and characterized by the XRD-Rietveld refinement; and by BET and TEM. As for the low-temperature-treated sample (200∘C, nanocrystals with small crystallite sizes (7 nm and high abundance of anatase, coexisting with the brookite phase, were obtained. Meanwhile, the sample annealed at 500∘C showed an increased crystallite size (22 nm and an important polymorphic increment. The sample annealed at 200∘C showed a high activity in the photocatalytic decomposition of acetaldehyde.

  19. Thermodynamics of Aldol Condensation of Acetaldehyde%乙醛缩合反应体系热力学计算和分析

    Institute of Scientific and Technical Information of China (English)

    伍艳辉; 梁泽磊; 刘剑; 刘仲能

    2011-01-01

    The standard enthalpies of formation, the standard Gibbs free energy of formation and the heat capacity of each compound in acetaldehyde condensation reaction system were calculated with the application of Yoneda group contribution method. Comparison of the calculated results with some literature values show that the calculation results are reliable.Then the reaction enthalpies, reaction Gibbs free energy changes and equilibrium constants of relevant reactions in this system from 278 K to 368 K in liquid phase and 600 K in vapor phase were calculated and analyzed. The results show that the temperature has important influence on the main reaction.Conducting the reactions in liquid phase at low temperature benefited the main reaction, while high temperature led to low conversion and selectivity. 2,4-hexadienoic aldehyde was the main by-product. The thermodynamic analysis agreed well with experimental results. Acetaldehyde condensation is not recommended to proceed at high temperature. To improve the conversion and selectivity of practical reaction, the temperature is proposed be controlled reasonably or the main product needs to be separated from the reactant in time.%采用Yoneda基团贡献法估算了乙醛羟醛缩合反应体系中各物质的标准生成焓、标准熵和等压热容,与部分文献值的比较表明估算较为准确.在此基础上计算了278-368 K液相反应和600 K气相反应时主、副反应的反应焓变、反应吉布斯自由能变和反应平衡常数.结果表明温度对主反应影响较大,低温液相反应对主反应有利,高温气相反应选择性低,主要副产物为2,4-己二烯醛.热力学分析与实验结果一致,乙醛缩合反应不宜采用高温气固相反应.因此实际生产中需对反应温度进行合理控制或对反应产物和原料及时分离,以提高反应转化率和选择性.

  20. Uptake and Reactions of Formaldehyde, Acetaldehyde, Acetone, Propanal and Ethanol in Sulfuric Acid solutions at 200-240 K: Implications for upper tropospheric aerosol composition

    Science.gov (United States)

    Iraci, L. T.; Williams, M. B.; Axson, J.; Michelsen, R.

    2007-12-01

    The production of light absorbing, organic material in aerosol that is normally considered to be transparent in the UV and visible wavelength regions has significant implications for biogeochemical cycling and climate modelling. Production mechanisms likely involve carbonyl compounds such as formaldehyde, acetone, acetaldehyde and propanal that are present in significant quantities in the upper troposphere (UT). In this study, we have performed experiments focusing on a class of acid catalyzed carbonyl reactions, the formation of acetals. R2C=O + 2R'OH --> R2C(OR')2 + H2O Using a Knudsen cell apparatus, we have measured the rate of uptake of formaldehyde, acetaldehyde, acetone, propanal, and ethanol into sulfuric acid solutions ranging between 40-70 wt% of acid, containing 0-0.1 M of ethanol, acetone or formaldehyde at temperatures of 220-250 K. For all reactant pairs, the aldol condensation path, including self reaction, should be insignificant at the acidities studied. Evidence for reaction between organics was observed for all pairs, except those involving propanal which were likely limited by the very low solubility. We attribute enhanced uptake to the formation of acetals, such as 1,1-diethoxyethane and 2,2- diethoxypropane, among others. Enhanced uptake was observed to proceed on timescales > 1 hour and sometimes shows complex dependence on acidity that is likely related to speciation of the individual carbonyls in acidic solution. The acetal products do not absorb in the visible but are less volatile than parent molecules, allowing for accumulation in sulfuric acid particles, and enhanced uptake. Cross reactions of carbonyls with alcohols in sulfuric acid medium have not been previously measured, yet methanol and ethanol show high solubility and are present at significant concentrations in the UT. Thus even at slow reaction rates, the acetal reaction has ample starting material and proceeds under conditions common to the UT. We will present results for the

  1. Mechanistic insights into the formation of acetaldehyde and diethyl ether from ethanol over support VO{sub x}, MoO{sub x}, and WO{sub x} catalysts.

    Energy Technology Data Exchange (ETDEWEB)

    Nair, H.; Gatt, J. E.; Miller, J. T.; Baertsch, C. D. (Chemical Sciences and Engineering Division); (Purdue Univ.)

    2011-04-01

    Catalytic pathways are described for reactions of ethanol to acetaldehyde by oxidative dehydrogenation and of ethanol to diethyl ether by condensation over VO{sub x}-Al{sub 2}O{sub 3}, MoO{sub x}-Al{sub 2}O{sub 3}, and WO{sub x}-Al{sub 2}O{sub 3}. Isotopic labeling shows that acetaldehyde formation occurs via rate-determining C-H bond cleavage of the CH{sub 2} group in an adsorbed alkoxide followed by removal of surface oxygen in a Mars and van Krevelen redox mechanism (as confirmed by in situ X-ray absorption, diffuse reflectance infra-red Fourier transform spectroscopy and UV-visible spectroscopy); diethyl ether formation occurs in parallel via coupling and condensation of two adjacent ethoxy species. Using a combination of in situ spectroscopic and kinetic analysis, catalyst properties influencing the formation of acetaldehyde and ether from the common adsorbed ethoxy intermediate are elucidated. X-ray absorption analysis during anaerobic ethanol titration is used to preclude the involvement of terminal MO bonds during the reaction. A study of the activity of catalysts with the same MoO{sub x} domain size on Al{sub 2}O{sub 3}, TiO{sub 2}, and CeO{sub 2} supports and binary oxides of MoO{sub x} and WO{sub x} on Al{sub 2}O{sub 3} are used to prove that the active redox oxygen for acetaldehyde formation is the oxygen atom linking the active metal oxide domain to the support oxide. Ether formation ability of the metal oxide is related to the electronegativity of the active metal atom.

  2. Hydrogen bonding interaction of small acetaldehyde clusters studied with core-electron excitation spectroscopy in the oxygen K-edge region

    International Nuclear Information System (INIS)

    In order to examine inner-shell electron excitation spectra of molecular clusters with strong multipole interactions, excitation spectra and time-of-flight (TOF) fragment-mass spectra of small acetaldehyde (AA) clusters have been studied under the beam conditions. The TOF spectra at the oxygen K-edge region showed an intense growth of the protonated clusters, MnH+ (M=CH3CHO) in the cluster beams. 'cluster-specific' excitation spectra could be generated by monitoring partial-ion-yields of the protonated clusters. The most intense band of O1s→π*CO was found to shift to a higher energy by 0.15 eV relative to the monomer band upon clusterization. X-ray absorption spectra (XAS) were also calculated for the representative dimer configurations using a computer modelling program based on the density functional theory. The XAS prediction for the most stable (non-planar) configuration was found to give a close comparison with the cluster-band shift observed. The band shift was interpreted as being due to the HOMO-LUMO interaction within the complex where a contribution of vibrationally blue-shifting hydrogen bonding could be identified.

  3. Determination of photo-catalytic activity of un-doped and Mn-doped TiO{sub 2} anatase powders on acetaldehyde under UV and visible light

    Energy Technology Data Exchange (ETDEWEB)

    Papadimitriou, Vassileios C., E-mail: bpapadim@chemistry.uoc.gr [Laboratory of Photochemistry and Kinetics, Department of Chemistry, University of Crete, 71003 Heraklion, Crete (Greece); Stefanopoulos, Vassileios G.; Romanias, Manolis N. [Laboratory of Photochemistry and Kinetics, Department of Chemistry, University of Crete, 71003 Heraklion, Crete (Greece); Papagiannakopoulos, Panos, E-mail: panosp@chemistry.uoc.gr [Laboratory of Photochemistry and Kinetics, Department of Chemistry, University of Crete, 71003 Heraklion, Crete (Greece); Sambani, Kyriaki; Tudose, Valentin; Kiriakidis, George [Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas, PO Box 1527,Vasilika Vouton, 71110 Heraklion, Crete (Greece)

    2011-12-01

    Titanium dioxide (TiO{sub 2}) photocatalytic powder materials doped with various levels of manganese (Mn) were synthesized to be used as additives to wall painting in combating indoor and outdoor air pollution. The heterogeneous photocatalytic degradation of gaseous acetaldehyde (CH{sub 3}CHO) on Mn-TiO{sub 2} surfaces under ultraviolet and visible (UV/Vis) irradiation was investigated, by employing the Photochemical Static Reactor coupled with Fourier-Transformed Infrared spectroscopy (PSR/FTIR) technique. Experiments were performed by exposing acetaldehyde ({approx} 400 Pa) and synthetic air mixtures ({approx} 1.01 Multiplication-Sign 10{sup 5} Pa total pressure) on un-doped TiO{sub 2} and doped with various levels of Mn (0.1-33% mole percentage) under UV and visible irradiation at room temperature. Photoactivation was initiated using either UV or visible light sources with known emission spectra. Initially, the photo-activity of CH{sub 3}CHO under the above light sources, and the physical adsorption of CH{sub 3}CHO on Mn-TiO{sub 2} samples in the absence of light were determined prior to the photocatalytic experiments. The photocatalytic loss of CH{sub 3}CHO on un-doped TiO{sub 2} and Mn-TiO{sub 2} samples in the absence and presence of UV or visible irradiation was measured over a long time period ( Almost-Equal-To 60 min), to evaluate their relative photocatalytic activity. The gaseous photocatalytic end products were also determined using absorption FTIR spectroscopy. Carbon dioxide (CO{sub 2}) was identified as the main photocatalysis product. It was found that 0.1% Mn-TiO{sub 2} samples resulted in the highest photocatalytic loss of CH{sub 3}CHO under visible irradiation. This efficiency was drastically diminished at higher levels of Mn doping (1-33%). The CO{sub 2} yields were the highest for 0.1% Mn-TiO{sub 2} samples under UV irradiation, in agreement with the observed highest CH{sub 3}CHO decomposition rates. It was demonstrated that low-level (0

  4. Liquid-Phase Aldol Condesation of Acetaldehyde and Its Kinetics%乙醛液相羟醛缩合反应工艺和动力学

    Institute of Scientific and Technical Information of China (English)

    伍艳辉; 任伟丽; 梁泽磊; 刘仲能; 吴高胜

    2013-01-01

    考察了KOH,NaOH,Na2CO3,NaOH和Na2CO3混合碱,三乙胺及阴离子交换树脂在乙醛缩合反应过程中的催化性能,以及反应体系的pH值和温度对反应的影响.结果表明,以Na2CO3为催化剂有利于维持反应体系pH稳定,当反应体系pH值为11~12,反应温度35℃时,反应转化率和选择性较高.在不同温度和pH值时进行动力学研究,得到pH值分别为10.4,11.0和11.4的动力学方程和相应的参数,其中pH值为11.4时,反应活化能最小.%The catalytic performance of different catalysts, KOH, NaOH, Na2CO3, mixed alkalis of NaOH and Na2CO3, triethylamine, and anionic exchange resin, in aldol condensation of acetaldehyde, were examined. The effects of solution pH level and reaction temperature on the reaction extent were investigated. The results indicate that a relatively constant pH level could be maintained with Na2CO3 as the catalyst. The reaction has a high conversion and a high selectivity at the reaction temperature of 35 ℃ and the pH range of 11-12. Kinetic studies were then carried out with Na2CO3 as the catalyst at different reaction temperatures and pH levels. The kinetic equations and the corresponding parameters were finally obtained for pH level of 10.4, 11.0, and 11.4, respectively. The activation energy at pH value of 11.4 is the lowest.

  5. Gene regulation to increase acetaldehyde and diacetyl production by lactic acid bacteria%发酵乳风味物质乙醛、双乙酰的合成途径及其调控机制

    Institute of Scientific and Technical Information of China (English)

    丹彤; 包秋华; 孟和毕力格; 王俊国; 张和平

    2012-01-01

    Lactic acid bacteria can produce flavor compounds, including alcohols, aldehydes and esters, among others, during fermentation. These bacteria also produce several organic acids, such as lactic acid, raw acetic acid, propionic acid, and others, during glycolysis. These organic acids can interact with flavor compounds to form unique flavors of fermented milk. Acetaldehyde and diacetyl have been recognized as important flavor components in yogurt. The present review article is focused on altering the acetaldehyde and diacetyl metabolic pathways as well as on increasing the production of these flavor compounds. The results of the studies conducted by domestic and foreign scholars on the regulation of the production of the acetaldehyde and diacetyl, as well as the synthesis pathways of these flavor compounds, are also summarized in the current paper.%乳酸菌在发酵过程中能够产生醇、醛、酮等多种风味物质,这些风味物质和乳酸菌在糖酵解过程中产生的乳酸、生醋酸、丙酸等有机酸相互作用,形成具有独特风味的发酵乳。在酸奶的风味物质中,乙醛、双乙酰是其主要成分。目前,关于酸奶风味物质研究的焦点主要集中在通过改变乙醛、双乙酰的代谢途径提高乙醛、双乙酰的产量上。这篇综述主要描述了乳酸菌在酸奶发酵过程中生产的风味物质、以及乙醛、双乙酰的合成途径和国内外学者在乙醛、双乙酰产量调控方面取得的研究成果。

  6. GC Determination of Acetaldehyde, Acrolein and Acrylonitrile in Water with Purge and Trap Technique%吹扫捕集-气相色谱法测定水中乙醛、丙烯醛、丙烯腈

    Institute of Scientific and Technical Information of China (English)

    陆文娟; 王晋宇; 陈玲瑚; 赵辰

    2011-01-01

    Purge and trap technique was applied in the GC determination of acetaldehyde, acrolein and acrylonitrile in water. The analytes were purged, trapped and thermodesorbed using the Trap Vocarb 3000, and determined by CR2 with flame ionization detector (FID). Linear relationships between values of peak area and mass concentration of acetaldehyde, acrolein and acrylonitrile obtained were same in the range of 0. 020--0.20 mg·L^-1 , with detection limits (3S/N) of 0. 005, 0. 010, 0. 001mg·L^-1 respectively. Tests for recovery and precision were made by standard addition method, values of recovery found were in the range of 90. 0%-110.0% and values of RSD's (n=7) were less than 50%.%提出了吹扫捕集-气相色谱法测定水中乙醛、丙烯醛和丙烯腈的分析方法。样品用Trap Vocarb 3000捕集阱吹扫、捕集及热解析后,用气相色谱法氢火焰离子化检测器分析。3种化合物的质量浓度在0.020~0.20mg·L^-1的相同范围内与其峰面积呈线性关系,方法的检出限(3S/N)分别为0.005,0.010,0.001mg·L^-。标准加入回收率在90.0%~110.0%之间,相对标准偏差(n=7)均小于5%。

  7. Solvent Effects on Nuclear Magnetic Resonance 2J(C,Hf and 1J(C,Hf Spin–Spin Coupling Constants in Acetaldehyde

    Directory of Open Access Journals (Sweden)

    Angel Esteban

    2003-02-01

    Full Text Available Abstract: The known solvent dependence of 1J(Cc,Hf and 2J(C1,Hf couplings in acetaldehyde is studied from a theoretical viewpoint based on the density functional theory approach where the dielectric solvent effect is taken into account with the polarizable continuum model. The four terms of scalar couplings, Fermi contact, paramagnetic spin orbital, diamagnetic spin orbital and spin dipolar, are calculated but the solvent effect analysis is restricted to the first term since for both couplings it is by far the dominant contribution. Experimental trends of Δ1J(Cc,Hf and Δ2J(C1,Hf Vs ε (the solvent dielectric constant are correctly reproduced although they are somewhat underestimated. Specific interactions between solute and solvent molecules are studied for dimethylsulfoxide, DMSO, solutions considering two different one-to-one molecular complexes between acetaldehyde and DMSO. They are determined by interactions of type C=O---H---C and S=O---H---C, and the effects of such interactions on 1J(Cc,Hf and 2J(C1,Hf couplings are analyzed. Even though only in a semiquantitative way, it is shown that the effect of such interactions on the solvent effects, of Δ1J(Cc,Hf and Δ2J(C1,Hf, tend to improve the agreement between calculated and experimental values. These results seem to indicate that a continuum dielectric model has not enough flexibility for describing quantitatively solvent effects on spin-spin couplings. Apparently, even for relatively weak hydrogen bonding, the contribution from “direct” interactions is of the same order of magnitude as the “dielectric” effect.

  8. Overview of VOC emissions and chemistry from PTR-TOF-MS measurements during the SusKat-ABC campaign: high acetaldehyde, isoprene and isocyanic acid in wintertime air of the Kathmandu Valley

    Science.gov (United States)

    Sarkar, Chinmoy; Sinha, Vinayak; Kumar, Vinod; Rupakheti, Maheswar; Panday, Arnico; Mahata, Khadak S.; Rupakheti, Dipesh; Kathayat, Bhogendra; Lawrence, Mark G.

    2016-03-01

    The Kathmandu Valley in Nepal suffers from severe wintertime air pollution. Volatile organic compounds (VOCs) are key constituents of air pollution, though their specific role in the valley is poorly understood due to insufficient data. During the SusKat-ABC (Sustainable Atmosphere for the Kathmandu Valley-Atmospheric Brown Clouds) field campaign conducted in Nepal in the winter of 2012-2013, a comprehensive study was carried out to characterise the chemical composition of ambient Kathmandu air, including the determination of speciated VOCs, by deploying a proton transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS) - the first such deployment in South Asia. In the study, 71 ion peaks (for which measured ambient concentrations exceeded the 2σ detection limit) were detected in the PTR-TOF-MS mass scan data, highlighting the chemical complexity of ambient air in the valley. Of the 71 species, 37 were found to have campaign average concentrations greater than 200 ppt and were identified based on their spectral characteristics, ambient diel profiles and correlation with specific emission tracers as a result of the high mass resolution (m / Δm > 4200) and temporal resolution (1 min) of the PTR-TOF-MS. The concentration ranking in the average VOC mixing ratios during our wintertime deployment was acetaldehyde (8.8 ppb) > methanol (7.4 ppb) > acetone + propanal (4.2 ppb) > benzene (2.7 ppb) > toluene (1.5 ppb) > isoprene (1.1 ppb) > acetonitrile (1.1 ppb) > C8-aromatics ( ˜ 1 ppb) > furan ( ˜ 0.5 ppb) > C9-aromatics (0.4 ppb). Distinct diel profiles were observed for the nominal isobaric compounds isoprene (m / z = 69.070) and furan (m / z = 69.033). Comparison with wintertime measurements from several locations elsewhere in the world showed mixing ratios of acetaldehyde ( ˜ 9 ppb), acetonitrile ( ˜ 1 ppb) and isoprene ( ˜ 1 ppb) to be among the highest reported to date. Two "new" ambient compounds, namely formamide (m / z = 46.029) and acetamide (m / z

  9. Eletroanálise de derivados acetaldeído com hidrazina e determinação em amostras de álcool combustível por voltametria de onda quadrada Electroanalysis of acetaldehyde derivatized with hydrazine and determination in fuel ethanol by square wave voltammetry

    Directory of Open Access Journals (Sweden)

    Vanessa S. Rodgher

    2006-07-01

    Full Text Available A square wave voltammetric method is described for the determination of acetaldehyde using the derivatization reaction with hydrazine sulphate, based on the reduction of hydrazone generated as a product that exhibits a single well-defined peak at -1.19V in acetate buffer at pH 5. Calibration graphs were obtained from 1.0 x 10-6 mol L-1 to 10 x 10-6 mol L-1 of acetaldehyde, using a reaction time of 8 min and a hidrazine concentration of 0.02 mol L-1. The detection limit was 2.38 x 10-7 mol L-1. The method was applied satisfactorily to the determination of total aldehyde in fuel ethanol samples without any pre-treatment.

  10. Impact of engineered Streptococcus thermophilus trains overexpressing glyA gene on folic acid and acetaldehyde production in fermented milk Impacto de linhagens de Streptococcus thermophilus com aumento da expressão do gene glyA na produção de ácido folico e acetaldeído em leite fermentado

    Directory of Open Access Journals (Sweden)

    Ana Carolina Sampaio Dória Chaves

    2003-11-01

    Full Text Available The typical yogurt flavor is caused by acetaldehyde produced through many different pathways by the yogurt starter bacteria L. bulgaricus and S. thermophilus. The attention was focused on one specific reaction for acetaldehyde and folic acid formation catalyzed by serine hydroxymethyltransferase (SHMT, encoded by the glyA gene. In S. thermophilus, this enzyme SHMT also plays the typical role of the enzyme threonine aldolase (TA that is the interconvertion of threonine into glycine and acetaldehyde. The behavior of engineered S. thermophilus strains in milk fermentation is described, folic acid and acetaldehyde production were measured and pH and counts were followed. The engineered S. thermophilus strains StA2305 and StB2305, have the glyA gene (encoding the enzyme serine hydroxymethyltransferase overexpressed. These engineered strains showed normal growth in milk when it was supplemented with Casitione. When they were used in milk fermentation it was observed an increase in folic acid and in acetaldehyde production by StA2305 and for StB2305 it was noticed a significative increase in folic acid formation.O acetaldeído, responsável pelo sabor e aroma característicos de iogurte, é produzido por diferentes vias metabólicas pelas bactérias lácticas: Streptococcus thermophilus (S. thermophilus e Lactobacillus delbrueckii subsp. bulgaricus (L. bulgaricus. Neste trabalho, a atenção foi focada especificamente na reação para a formação de acetaldeído e de ácido fólico, catalisada pela enzima serina hidroximetil transferase (SHMT, codificada pelo gene glyA. A enzima SHMT catalisa diversas reações e, no caso da bactéria S. thermophilus, ela exerce também a atividade característica da enzima treonina aldolase (TA, definida como a interconversão do aminoácido treonina em glicina e acetaldeído. Foram construídas linhagens de S. thermophilus (StA2305 e StB2305 com super expressão do gene glyA. Estas linhagens modificadas apresentaram

  11. Effect of caffeine on proliferation,apoptosis in hepatic stellate cell-T6 stimulated by acetaldehyde and its partial mechanisms%咖啡因对乙醛刺激的大鼠肝星状细胞HSC-T6增殖、凋亡的影响及部分作用机制代

    Institute of Scientific and Technical Information of China (English)

    代雪飞; 吕雄文; 管文婕; 杨万枝; 李俊

    2011-01-01

    目的 探讨咖啡因(CAF)对乙醛刺激的大鼠肝星状细胞(HSC)-T6增殖、凋亡的影响及部分作用机制.方法用不同浓度的CAF(0.5、1、2、4、8 mmol/L)对乙醛刺激的HSC-T6进行处理,四甲基偶氮唑蓝(MTT)法检测细胞增殖;流式细胞仪检测细胞凋亡及细胞周期分布;RT-PCR法检测HSC-T6中平滑肌肌动蛋白(α-SMA)、肿瘤坏死因子相关凋亡诱导配体(TRAIL)受体DR4、DR5的mRNA表达.结果 CAF对乙醛刺激的大鼠HSC-T6增殖具有抑制作用,阻滞细胞于G0/G1期;能够明显下调HSC-T6中α-SMA的mRNA表达,上调DR4、DR5的mRNA表达.结论 CAF对乙醛刺激的HSC-T6增殖具有抑制作用,并能够促进其凋亡,其机制可能与TRAIL受体DR4、DR5的表达有关.%Objective To explore the effect of caffeine on proliferation, apoptosis in hepatic stellate cell-T6( HSCT6 ) stimulated by acetaldehyde and its partial mechanisms. Methods HSC-T6 stimulated by acetaldehyde was incubated with different doses of caffeine( 0. 5 ,1 .2 ,4 ,8 mmol/L ) , cell proliferation was analyzed by MTT colorimetric assay, apoptosis rate and the cell cycle distribution were analyzed by flow cytometry( FCM ). The mRNA expressions of a-SMA.TRAIL receptor DR4 and DR5 were measured by RT-PCR. Results Caffeine could inhibit HSCT6 stimulated by acetaldehyde,the cells were accumulated in the G0/G1 phase. The mRNA expression levels of αSMA decreased,but DR4 and DR5 increased. Conclusion Caffeine can inhibit the growth of HSC-T6 stimulated by acetaldehyde and promote the apoptosis,the mechanisms may be related to the expression of TRAIL receptor DR4 and DR5.

  12. 静态顶空气相色谱法对土壤中乙醛等物质分析及研究%Analysis and Research of the Substances in Soils Such as Acetaldehyde by Static Headspace-Gas Chromatography

    Institute of Scientific and Technical Information of China (English)

    郭艳

    2015-01-01

    In this research, static headspace technology is used for preliminary treatment of soils and a detection and analysis method of determination of acetaldehyde, acrolein, acrylonitrile and pyridine in soils is set up by static headspace–gas chromatography. Under a certain condition of static headspace-gas chromatography, time and temperature for static headspace is optimized and detection limits for determination of acetaldehyde, acrolein, acrylonitrile, and pyridine in soils by static headspace–gas chromatography are identified, with satisfactory separation efect, linear regression equation, precision and accuracy achieved. The results indicate that analysis of the target compounds in soils by headspace-gas chromatography can reduce the loss of the organic matter in soils to be determined and improve sensitivity and accuracy of the experimentalanalysis.%研究用静态顶空技术处理土壤,从而建立了静态顶空-气相色谱(GC-FID)测定土壤中的乙醛、丙烯醛、丙烯腈和吡啶的检测分析方法。在一定的静态顶空和气相色谱条件下,进行了顶空的时间和温度优化,确定了静态顶空气相色谱法测定土壤中乙醛、丙烯醛、丙烯腈和吡啶方法的检出限,并取得了满意的分离效果、线性回归方程、精密度和准确度。结果表明:用顶空气相色谱法处理土壤样品,可以减少土壤中待测有机物的损失,提高实验分析的灵敏度和准确度。

  13. Acetaldehyde dehydrogenase 2 activation inhibits myocardial ischemia-reperfusion injury in senescent rats%激活乙醛脱氢酶2抑制老年大鼠心肌缺血再灌注损伤

    Institute of Scientific and Technical Information of China (English)

    邢媛; 殷玥; 石曌玲; 李晨; 王博文; 王衍帅; 高峰; 马恒

    2013-01-01

    Objective Aging heart shows significantly reduced tolerance to myocardial ischemia/reperfusion (I/R) injury, so senescent heart is prone to be damaged by the injury. This study was designed to investigate the protective effect of acetaldehyde dehydrogenase 2 (ALDH2) agonist Alda-1 in aging rats after myocardial I/R injury. Methods A total of 40 aging male Sprague Dawley (SD) rats (at an age of 20 to 22 months) were randomized into I/R group (I/R) and Alda-1 group (I/R + Alda). Another 40 adult rats at an age of 3 to 4 months served as adult control. Rat acute myocardial I/R model was established by ligation of left anterior descending artery for 30min followed by reperfusion for 4h. Alda-l(16mg/kg) and normal saline at the same volume were intravenously infused at a flow rate of 2ml/(kg · h) into the left ventricle of corresponding rats in 5min before reperfusion. The left ventricular pressure was monitored at the same time. At the end of 4 hours reperfusion, ALDH2 activity, reactive oxygen species (ROS) production, and protein carbonylation in the myocardial tissue were measured. Serum level of lactate dehydrogenase (LDH) was tested. Results A significant decrease in ALDH2 activity was observed in the aging hearts, but this effect was blocked by Alda-1. Compared with the adult hearts, myocardial I/R injury was significantly aggravated in aging hearts, which were evidenced by reduced ± LVdP/dtmax and increased serum level of LDH (P < 0.05). ALDH2 activator infusion during reperfusion effectively suppressed the above mentioned ischemic injury in the aging hearts (P < 0.05). Furthermore, protein carbonylation and ROS production in the myocardium were increased in the aging hearts compared with the adult hearts (P < 0.05), which was attenuated by Alda-1 treatment. Conclusion Activating myocardial ALDH2 significantly improves the resistance ability to myocardial I/R injury in aging heart. ALDH2-induced cardiac protection may be through suppressing myocardial I

  14. Effect of caffeine on signaling transduction of TGF-β1 and CTGF in hepatic stellate cell-T6 stimulated by acetaldehyde%咖啡因对乙醛诱导的HSC-T6中TGF-β1,CTGF信号转导通路的影响

    Institute of Scientific and Technical Information of China (English)

    管文婕; 吕雄文; 杨万枝; 李俊

    2012-01-01

    Objective To explore the effect of caffeine on proliferation in hepatic stellate cell stimulated by acetaldehyde and its signaling pathway of TGF-β and CTGF. Methods Trials are divided into normal group( regular training ), model group, adenosine receptor group,which were given caffeine( 4 mmol · L-1 ),adenosine A2A receptor antagonist ZM241385( 1 μmol · L-1 ),adenosine A2A receptor agonists CGS21680( 1 μmol · L-1 ),caffeine + CGS21680,ZM241385 + CGS21680 and HSC-T6 respectively,stimulated by acetaldehyde after 1 h,before continueing to cultivate 48 h. The protein expression of a-SMA was analyzed by immunocytochemistry methods. The mR-NA expressions of TGF-β1 and CTGF were measured by RT-PCR. The protein expression of CTGF was analyzed by western blot methods. Results Caffeine or ZM241385 treatment inhibited the increase expressions of TGF-β1, CTGF, α-SMA in the HSC-T6,likewise,as with CGS21680 plus caffeine or ZM241385 groups, caffeine or ZM241385 prevented the adenosine A2A receptor agonist from stimulating an increase in hepatic stellate cell. Conclusion Caffeine can suppress the activation of α-SMA in HSC-T6 stimulated by acetaldehyde. Caffeine treatment inhibited the increase expressions of TGF-βl and CTGF in the HSC-T6,the mechanisms of which may be related to the expression of adenosine A2A receptor.%目的 探讨咖啡因(caffeine)对乙醛诱导的大鼠肝星状细胞系(Hepatic Stellate Cell-T6,HSC-T6)中转化生长因子-β1(Transforming Growth Factor-β1,TGF-β1),结缔组织生长因子(Connective Tissue Growth Factor,CTGF)信号转导通路的影响.方法 实验设正常组(常规培养),模型组及腺苷受体(Adenosine Receptor,AR)调节剂干预组.分别给予caffeine(4 mmol·L-1)[1-2],腺苷A2A受体拮抗剂ZM241385(1 μmol·L-1)[3],腺苷A2A受体激动剂CGS21680(1 μmol·L-1)[3],caffeine+CGS21680,ZM241385+CGS21680 与HSC-T6共同培养,1 h后加入终浓度200 μmol·L-1的乙醛刺激(每12 h补充1次),继续培养48 h.采

  15. Candida yeasts and carcinogenic acetaldehyde in upper digestive tract carcinogenesis

    OpenAIRE

    Nieminen, Mikko

    2014-01-01

    Cancers of the upper digestive tract (oral, pharyngeal, laryngeal, oesophageal and stomach) are among the ten most common cancers worldwide and are associated with high mortality and morbidity. Despite improved treatment strategies, the prognosis of these cancers remains poor. The main aetiological factors for the upper digestive tract cancers are alcohol consumption and smoking. Dietary and genetic factors can also contribute to an increased risk. Alcohol consumption, smoking and poor oral h...

  16. The effects of different concentrations of nitroglycerin on cardiac ischemia and reperfusion injury and the mechanism of mitochondrial acetaldehyde dehydrogenase 2%不同浓度硝酸甘油对心脏缺血/再灌注的作用及ALDH2的作用

    Institute of Scientific and Technical Information of China (English)

    王晓梅; 李正红; 夏满莉; 胡杰; 姜翠荣; 高琴

    2011-01-01

    目的 探讨不同浓度硝酸甘油(GTN)对离体大鼠心脏缺血/再灌注损伤的作用,进一步分析线粒体乙醛脱氢酶2(ALDH2)在其中的作用.方法 采用离体大鼠心脏Langendorff灌流方法,局部结扎冠状动脉左前降支30 min,复灌30 min复制缺血/再灌注模型.实验分五组,正常对照组,单纯缺血/再灌注组,GTN低浓度组(10 -8 mol/L GTN),中浓度组(10-7 mol/L GTN)及高浓度组(2×10 -6 mol/L GTN).测定心室动力学指标和复灌期间冠脉流出液中乳酸脱氢酶( lactate dehydrogenase,LDH)含量,RT-PCR测定左心室前壁心尖组织线粒体ALDH2基因mRNA表达水平.结果 与单纯缺血/再灌注组相比,GTN低浓度组左心室发展压(LVDP)、室内压最大上升/下降速率(±dp/dtmax)均增高,左心室舒张末压(LVEDP)降低,中浓度组无明显差异,高浓度组LVDP和±dp/dtmax均降低;LVEDP增高.与缺血/再灌注组相比,正常对照组和低浓度GTN组心肌组织ALDH2 mRNA表达增高,中浓度无明显差异,高浓度组大鼠心肌ALDH2 mRNA表达降低.结论 低浓度GTN可对抗心肌缺血/再灌注损伤,高浓度GTN加重损伤,中浓度GTN对损伤影响不大,此现象可能与不同浓度GTN引起心肌ALDH2的释放量不同有关.%Objective To investigate the effects of different concentrations of nitroglycerin ( GTN) in isolated rat hearts subjected to ischemia and reperfusion (I/R) injury and the role of mitochondrial acetaldehyde dehydrogenase 2 ( ALDH2). Methods The isolated perfused rat hearts were subjected to 30 min local ischemia and 30 min reperfusion. The rats were divided into control, I/R, low concentration GTN (10~8 mol/L GTN) , middle concentration GTN (10~7 mol/L GTN) group, high concentration GTN (2 xlO"6 mol/L GTN) groups. The ventricular hemodynamic parameters and lactate dehydrogenase (LDH) release during reperfusion were measured. The ALDH2 mRNA expression of left anterior myocardium was detected by reverse transcriptase polymerase chain

  17. Quantum chemical and topological study on the insertion reaction of dichlorcarbene with acetaldehyde

    Institute of Scientific and Technical Information of China (English)

    LI ZhiFeng; ZHU YuanCheng; YANG Sheng; LU XiaoQuan

    2008-01-01

    The insertion reaction mechanisms of siglet and striglet CCI2with CH3CHO have been studied by using the DFT, NBO, CCSD(T) and AIM method. The geometries of reactions, transition state and products were completely optimized by B3LYP/6-31G(d). All the energy of the species was obtained at the CCSD(T)/6-31G(d,p) level. The calculated results indicated that all the major pathways of the reaction were obtained on the singlet potential energy surface. The singlet CCI2can not only insert the Cα--H (reaction Ⅰ) but also can react with Cβ--H (reaction Ⅱ). There are three main existing pathways and the products are P1 (CH3COHCCI2), P2 (CH2COHCHCI2) and P4[CHCI2CHCHOH] respectively. Reaction Ⅱ happens more easily according to the energy changes and the barrier in rate-controlling step. In addition, the important geometries in domain pathways have been studied by AIM theory. And also, the energy changes of H in the inserted C--H bond have been investigated.

  18. Relative tropospheric photolysis rates of acetaldehyde and formaldehyde measured at the European Photoreactor Facility

    DEFF Research Database (Denmark)

    Nilsson, Elna Johanna Kristina; Bache-Andreassen, Lihn; Johnson, Matthew Stanley;

    2009-01-01

    The photolysis rates of HCHO, DCDO, CH3CHO, and CH3CDO are studied by long-path FTIR spectroscopy in natural tropospheric conditions at the European Photoreactor Facility (EUPHORE) in Valencia, Spain. Average relative photolysis rates jHCHO/jDCDO ) 3.15 ( 0.08 and jCH3CHO/jCH3CDO ) 1.26 ( 0...

  19. Real-time trace gas sensing of ethylene, propanal and acetaldehyde from human skin in vivo.

    NARCIS (Netherlands)

    Moeskops, B.W.M.; Steeghs, M.M.L.; Swam, K. van; Cristescu, S.M.; Scheepers, P.T.J.; Harren, F.J.M.

    2006-01-01

    Trace gases emitted by human skin in vivo are monitored non-invasively and in real time using laser-based photoacoustic detection and proton-transfer reaction mass spectrometry. A small quartz cuvette is placed on the skin to create a headspace from which a carrier gas transports the skin emissions

  20. Genetic determinants of both ethanol and acetaldehyde metabolism influence alcohol hypersensitivity and drinking behaviour among Scandinavians

    DEFF Research Database (Denmark)

    Linneberg, A; Gonzalez-Quintela, A; Vidal, C;

    2010-01-01

    Although hypersensitivity reactions following intake of alcoholic drinks are common in Caucasians, the underlying mechanisms and clinical significance are not known. In contrast, in Asians, alcohol-induced asthma and flushing have been shown to be because of a single nucleotide polymorphism (SNP)...

  1. Water and acetaldehyde in HH212: The first hot corino in Orion

    CERN Document Server

    Codella, C; Cabrit, S; Podio, L; Bachiller, R; Fontani, F; Gusdorf, A; Lefloch, B; Leurini, S; Tafalla, M

    2016-01-01

    Aims: Using the unprecedented combination of high resolution and sensitivity offered by ALMA, we aim to investigate whether and how hot corinos, circumstellar disks, and ejected gas are related in young solar-mass protostars. Methods: We observed CH$_3$CHO and deuterated water (HDO) high-excitation ($E_{\\rm u}$ up to 335 K) lines towards the Sun-like protostar HH212--MM1. Results: For the first time, we have obtained images of CH$_3$CHO and HDO emission in the inner $\\simeq$ 100 AU of HH212. The multifrequency line analysis allows us to contrain the density ($\\geq$ 10$^{7}$ cm$^{-3}$), temperature ($\\simeq$ 100 K), and CH$_3$CHO abundance ($\\simeq$ 0.2--2 $\\times$ 10$^{-9}$) of the emitting region. The HDO profile is asymmetric at low velocities ($\\leq$ 2 km s$^{-1}$ from $V_{\\rm sys}$). If the HDO line is optically thick, this points to an extremely small ($\\sim$ 20--40 AU) and dense ($\\ge$ 10$^{9}$ cm$^{-3}$) emitting region. Conclusions: We report the first detection of a hot corino in Orion. The HDO asymm...

  2. Roaming is the dominant mechanism for molecular products in acetaldehyde photodissociation

    OpenAIRE

    Heazlewood, Brianna R.; Jordan, Meredith J. T.; Kable, Scott H.; Selby, Talitha M.; Osborn, David L.; Shepler, Benjamin C.; Braams, Bastiaan J.; Joel M. Bowman

    2008-01-01

    Reaction pathways that bypass the conventional saddle-point transition state (TS) are of considerable interest and importance. An example of such a pathway, termed “roaming,” has been described in the photodissociation of H2CO. In a combined experimental and theoretical study, we show that roaming pathways are important in the 308-nm photodissociation of CH3CHO to CH4 + CO. The CH4 product is found to have extreme vibrational excitation, with the vibrational distribution peaked at ≈95% of the...

  3. Oscillatory Ignitions and Cool Flames Accompanying the Non-Isothermal Oxidation of Acetaldehyde in a Well Stirred, Flow Reactor

    Science.gov (United States)

    Gray, P.; Griffiths, J. F.; Hasko, S. M.; Lignola, P.-G.

    1981-02-01

    At the various boundaries between the five regions, sharp jumps occur from one kind of behaviour to another. At three segments of the boundary, there is hysteresis, the jumps occurring at different temperatures during heating (I --> II, III or IV) and cooling (II, III or IV --> I) traverses. There are thus regions of bistability, where identical external conditions - vessel temperatures, reactant pressures and flow rates - can give rise to alternative states inside the reactor. The two non-oscillatory, stationary states have different characters: I is a stable node and V is a stable focus. In region I, the reaction rate increases with temperature; but in region V, both reaction rate and extent of self-heating show a near-zero or negative temperature-coefficient.

  4. Neurobiological and genetic aspects of alcohol addiction: a special focus on acetaldehyde, the first metabolite of ethanol

    OpenAIRE

    Quertemont, Etienne

    2007-01-01

    Although alcoholism is one of the most common forms of addiction, its neurobiological mechanisms still remain unclear. The reinforcing properties of ethanol are mediated by the interaction of multiple neurotransmitter systems, including dopamine, serotonin, glutamate, GABA, endogenous opioids and endocannabinoids. Additionally, long term changes in these neurotransmitter systems are believed to promote the development of alcoholism, probably through specific alterations of brain regions invol...

  5. Effect of the allelic variants of aldehyde dehydrogenase ALDH2*2 and alcohol dehydrogenase ADH1B*2 on blood acetaldehyde concentrations

    OpenAIRE

    Peng Giia-Sheun; Yin Shih-Jiun

    2009-01-01

    Abstract Alcoholism is a complex behavioural disorder. Molecular genetics studies have identified numerous candidate genes associated with alcoholism. It is crucial to verify the disease susceptibility genes by correlating the pinpointed allelic variations to the causal phenotypes. Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) are the principal enzymes responsible for ethanol metabolism in humans. Both ADH and ALDH exhibit functional polymorphisms among racial populations; the...

  6. [Effect of Bacillus natto-fermented product (BIOZYME) on blood alcohol, aldehyde concentrations after whisky drinking in human volunteers, and acute toxicity of acetaldehyde in mice].

    Science.gov (United States)

    Sumi, H; Yatagai, C; Wada, H; Yoshida, E; Maruyama, M

    1995-04-01

    Effects of Bacillus natto-fermented product (BIOZYME) on blood alcohol and aldehyde concentrations after drinking whisky (corresponding to 30-65 ml ethanol) were studied in 21 healthy volunteers. When 100 ml of BIOZYME was orally administrated to the volunteers before drinking whisky, the time delay of both blood factors to attain maximum concentrations were observed. The maximum decrease in blood alcohol and aldehyde concentrations were about 23% and 45% (p whisky. The aldehyde lowering effect of BIOZYME was continued for at least 4 hr after whisky drinking. Concentration of the breath alcohol was also sharply decreased by BIOZYME administration. The breath alcohol concentration in the administered group (0.18 +/- 0.11 mg/l) was found to be lowered about 44% than that of the control group (0.32 +/- 0.11 mg/l) (p whisky. In acute toxicity experiments of aldehyde in mice (12 mmol AcH/mg), BIOZYME showed the survival effect as with alpha-D-Ala (134% increase of the living, at 40 min after i.p. administration) (p < 0.005, n = 22). These findings reveal the Bacillus natto produced BIOZYME as a reasonable, safety and useful anti-hangover agent.

  7. Prospecting for Acetaldehyde-tolerant DERAs from Thermophilic Microorganism%嗜热微生物中获取耐乙醛变性醛缩酶

    Institute of Scientific and Technical Information of China (English)

    李铖璐; 杜鹏飞; 裴晓林; 吴慧丽; 谢开林; 王秋岩

    2010-01-01

    在催化他汀药物中间体合成中,对高浓度乙醛底物的耐受是醛缩酶的重要应用性质.通过克隆并在大肠杆菌中过表达了来源于嗜热微生物Geobacillus thermodenitrificans的耐热醛缩酶(DERAGth),该蛋白质序列长度为223 aa,对应的分子量为25.0 kD.初步酶学性质表征结果表明,该酶对天然底物2-脱氧核酸-5-磷酸的活力19.3 U/mg,最适pH为7.5,最适温度为60 ℃.在40-100 ℃保温10 min的结果表明,DERAGth具有较好的热稳定性,在60 ℃下10 min活力仍保持100%.对乙醛耐受的实验表明,该酶在300 mmol乙醛中25 ℃保温2 h,剩余活力高于40%.连续醛缩活力对比实验结果表明,该酶的连续醛缩活力远大于来源于常温微生物的大肠杆菌醛缩酶.

  8. The thiocarbamate disulphide drug, disulfiram induces osteopenia in rats by inhibition of osteoblast function due to suppression of acetaldehyde dehydrogenase activity.

    Science.gov (United States)

    Mittal, Monika; Khan, Kainat; Pal, Subhashis; Porwal, Konica; China, Shyamsundar Pal; Barbhuyan, Tarun K; Baghel, Khemraj S; Rawat, Tara; Sanyal, Sabyasachi; Bhadauria, Smrati; Sharma, Vishnu L; Chattopadhyay, Naibedya

    2014-05-01

    Dithiocarbamates (DTC), a sulfhydryl group containing compounds, are extensively used by humans that include metam and thiram due to their pesticide properties, and disulfiram (DSF) as an alcohol deterrent. We screened these DTC in an osteoblast viability assay. DSF exhibited the highest cytotoxicity (IC50 488nM). Loss in osteoblast viability and proliferation was due to induction of apoptosis via G1 arrest. DSF treatment to osteoblasts reduced glutathione (GSH) levels and exogenous addition of GSH prevented DSF-induced reactive oxygen species generation and osteoblast apoptosis. DSF also inhibited osteoblast differentiation in vitro and in vivo, and the effect was associated with inhibition of aldehyde dehydrogenase (ALDH) activity. Out of various ALDH isozymes, osteoblasts expressed only ALDH2 and DSF downregulated its transcript as well as activity. Alda-1, a specific activator of ALDH2, stimulated osteoblast differentiation. Subcutaneous injection of DSF over the calvarium of new born rats reduced the differentiation phenotype of calvarial osteoblasts but increased the mRNA levels of Runx-2 and osteocalcin. DSF treatment at a human-equivalent dose of 30 mg/kg p.o. to adult Sprague Dawley rats caused trabecular osteopenia and suppressed the formation of mineralized nodule by bone marrow stromal cells. Moreover, DSF diminished bone regeneration at the fracture site. In growing rats, DSF diminished growth plate height, primary and secondary spongiosa, mineralized osteoid and trabecular strength. Substantial decreased bone formation was also observed in the cortical site of these rats. We conclude that DSF has a strong osteopenia inducing effect by impairing osteoblast survival and differentiation due to the inhibition of ALDH2 function. PMID:24496638

  9. 乙醇脱氢制备乙醛适宜温度的选择%Discussion on Optimum Temperature for Dehydrogenation of Ethanol to Acetaldehyde

    Institute of Scientific and Technical Information of China (English)

    丁爱军; 王金龙

    2011-01-01

    从化学热力学角度探讨乙醇直接脱氢和氧化脱氢的反应属性,认为直接脱氢的反应温度应高于322.5℃.说明决定反应温度的相关要素,对化学教学中相应的反应温度提出建议.

  10. Study on Aldol Condensation of Acetaldehyde and Formaldehyde%甲醛、乙醛气相缩合生成丙烯醛的研究

    Institute of Scientific and Technical Information of China (English)

    杨菊群

    2008-01-01

    对SiO2及其用碱土金属、稀土金属修饰的混合氧化物催化剂进行了表征,并研究了其对甲醛、乙醛缩合生成丙烯醛的催化性能,详细考察了甲醛、乙醛的摩尔比;反应温度;投料速度对乙醛的转化率和生成丙烯醛的选择性等的影响.

  11. IGHV1-69-Encoded Antibodies Expressed in Chronic Lymphocytic Leukemia React with Malondialdehyde-Acetaldehyde Adduct, an Immunodominant Oxidation-Specific Epitope

    DEFF Research Database (Denmark)

    Que, Xuchu; Widhopf Ii, George F; Amir, Shahzada;

    2013-01-01

    The immunoglobulins expressed by chronic lymphocytic leukemia (CLL) B cells are highly restricted, suggesting they are selected for binding either self or foreign antigen. Of the immunoglobulin heavy-chain variable (IGHV) genes expressed in CLL, IGHV1-69 is the most common, and often is expressed...

  12. Poor Metabolizing of Ethanol and Acetaldehyde with alcohol-related Traffic Accident%乙醇、乙醛慢代谢与酒后驾车肇事

    Institute of Scientific and Technical Information of China (English)

    李莉; 李成涛; 赵书民; 张素华; 向平

    2010-01-01

    在体内乙醇代谢过程中起重要作用的酶有乙醇脱氢酶(ADH)、乙醛脱氢酶(ALDH)和细胞色素P4502E1酶(CYP2E1),它们均具有基因多态性,不同基因型个体对乙醇的耐受性存在差别,表现为酒后的行为反应能力不同.司机若为慢代谢型,乙醇、乙醛代谢速率低下,即使少量饮酒,酒后开车也可造成交通肇事.通过对ADH、ALDH和CYP2E1基因多态性与乙醇、乙醛代谢能力的关系进行综述.

  13. 高效液相色谱法测定指甲油中甲醛、乙醛和丙酮%HPLC Determination of Formaldehyde, Acetaldehyde and Acetone in Nail Polish

    Institute of Scientific and Technical Information of China (English)

    吴飞; 夏俊鹏

    2015-01-01

    采用高效液相色谱法测定指甲油中甲醛、乙醛和丙酮的含量.样品用乙腈和水提取,2,4-二硝基苯肼为衍生剂,采用Kromasil-C18色谱柱为分离柱,以乙腈-水(65+35)溶液为流动相,在检测波长364 nm处进行测定.甲醛、乙醛和丙酮的质量浓度均在0.01~20.0 mg·L-1范围内与其峰面积呈线性关系,方法的检出限(3S/N)在0.001 5~0.003 5 mg·L-1之间.加标回收率在88.6%~110%之间,相对标准偏差(n=6)在1.2%~9.7%之间.

  14. Sequence Classification: 390200 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|31794711|ref|NP_857204.1| PROBABLE ACETA...LDEHYDE DEHYDROGENASE (ACETALDEHYDE DEHYDROGENASE || http://www.ncbi.nlm.nih.gov/protein/31794711 ...

  15. Sequence Classification: 399976 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|15610671|ref|NP_218052.1| PROBABLE ACETA...LDEHYDE DEHYDROGENASE (ACETALDEHYDE DEHYDROGENASE || http://www.ncbi.nlm.nih.gov/protein/15610671 ...

  16. Biotransformation of Benzaldehyde to L-Phenylacetylcarbinol (L-PAC by Free Cells of Torulaspora delbrueckii in presence of Beta-Cyclodextrin

    Directory of Open Access Journals (Sweden)

    Vilas. B. Shukla

    2002-09-01

    Full Text Available Studies were carried out to explore the possibility of decreasing the toxic and inhibitory effects of the substrate benzaldehyde during its biotransformation to L-PAC by free cells of Torulaspora delbrueckii using beta -cyclodextrin (beta -CD. Use of various levels of benzaldehyde and acetaldehyde in presence of 2% of beta -CD showed that, in presence of beta -CD, the organism could tolerate higher levels of benzaldehyde and acetaldehyde. Semi-continuous feeding of benzaldehyde and acetaldehyde was found to increase the yield of L-PAC in comparison with one time feeding.

  17. Cyanohydrin reactions enhance glycolytic oscillations in yeast

    DEFF Research Database (Denmark)

    Hald, Bjørn Olav; Nielsen, Astrid Gram; Tortzen, Christian;

    2015-01-01

    Synchronous metabolic oscillations can be induced in yeast by addition of glucose and removal of extracellular acetaldehyde (ACAx). Compared to other means of ACAx removal, cyanide robustly induces oscillations, indicating additional cyanide reactions besides ACA to lactonitrile conversion. Here...

  18. Electrocatalytic Activity of Pt/C Electrodes for Ethanol Oxidation in Vapor Phase

    Institute of Scientific and Technical Information of China (English)

    LIANG Hong; YE Dai-qi; LIN Wei-ming

    2005-01-01

    High performance platinized-carbon electrodes have been developed for the electrocatalytic oxidation of ethanol to acetaldehyde in electrogenerative processes. A load current density of the electrode can be achieved as high as 600 mA per square centimeter for oxygen reducing in 3 mol/L sulfuric acid with a good stability. With these electrodes and sulfuric acid as an electrolyte in fuel cells, ethanol vapor carried by nitrogen gas can be oxidized selectively to acetaldehyde. Selectivity of acetaldehyde depends on the potential of the cell and the feed rate of ethanol vapor and it can be more than 80% under optimized conditions. The initial product of ethanol oxidized on a platinized-carbon electrode is acetaldehyde and the ethanol oxidation mechanism is discussed.

  19. 21 CFR 177.2410 - Phenolic resins in molded articles.

    Science.gov (United States)

    2010-04-01

    ... produced when phenol is made to react with styrene in the presence of sulfuric acid catalyst. (2) Aldehydes: Acetaldehyde. Formaldehyde. Paraldehyde. (b) Optional adjuvant substances employed in the production of...

  20. Isolation of methylglyoxal from liver.

    Science.gov (United States)

    Fodor, G; Mujumdar, R; Szent-Gyorgyi, A

    1978-01-01

    Acetaldehyde and methylglyoxal were shown to be present in liver bound to protein. They were isolated in the form of 2,4-dinitrophenylhydrazones and osazones, respectively. The NMR spectrum of pure methylglyoxal was recorded. PMID:279916

  1. 21 CFR 172.712 - 1,3-Butylene glycol.

    Science.gov (United States)

    2010-04-01

    ...: (a) It is prepared by the aldol condensation of acetaldehyde followed by catalytic hydrogenation. (b... reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are available from the Office...

  2. Production of methanol from heat-stressed pepper and corn leaf disks

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, J.A. (Oklahoma State Univ., Stillwater, OK (United States). Dept. of Horticulture and Landscape Architecture)

    1994-05-01

    Early Calwonder'' pepper (Capsicum annuum L.) and Jubilee'' corn (Zea mays L.) leaf disks exposed to high temperature stress produced ethylene, ethane, methanol, acetaldehyde, and ethanol based on comparison of retention times during gas chromatography to authentic standards. Methanol, ethanol, and acetaldehyde were also identified by mass spectroscopy. Corn leaf disks produced lower levels of ethylene, ethane, and methanol, but more acetaldehyde and ethanol than pepper. Production of ethane, a by-product of lipid peroxidation, coincided with an increase in electrolyte leakage (EL) in pepper but not in corn. Compared with controls, pepper leaf disks infiltrated with linolenic acid evolved significantly greater amounts of ethane, acetaldehyde, and methanol and similar levels of ethanol. EL and volatile hydrocarbon production were not affected by fatty acid infiltration in corn. Infiltration of pepper leaves with buffers increasing in pH from 5.5 to 9.5 increased methanol production.

  3. A novel, inducible, citral lyase purified from spores of Penicillium digitatum

    NARCIS (Netherlands)

    Wolken, W.A.M.; Loo, W.J.V. van; Tramper, J.; Werf, M.J. van der

    2002-01-01

    A novel lyase, combining hydratase and aldolase activity, that converts citral into methylheptenone and acetaldehyde, was purified from spores of Penicillium digitatum. Remarkably, citral lyase activity was induced 118-fold by incubating nongerminating spores with the substrate, citral. This cofacto

  4. Influence of Distillation System, Oak Wood Type, and Aging Time on Volatile Compounds of Cider Brandy

    OpenAIRE

    Rodríguez, Roberto; Blanco-Gomis, Domingo; Mangas, J.J. (Juan)

    2012-01-01

    A study of the influence of distillation system, oak wood type, and aging time on volatile compounds of cider brandy was carried out. Acetaldehyde and acetaldehyde diethyl acetal were influenced by distillation technology, oak wood type, and maturation time. The majority ester, ethyl ethanoate, increased during aging, the highest level of this ester being detected in spirits distilled by double distillation. The alcohols of higher molecular weight were better recovered in the rectification co...

  5. A Kinetic Study of Selective Hydrogenation of Carbon Monoxide to C2 Oxygenates on Rh-Mn-Li-Fe/SiO2 Catalyst

    Institute of Scientific and Technical Information of China (English)

    Hongmei Yin; Yunjie Ding; Hongyuan Luo; Daiping He; Weimiao Chen; Zhiyong Ao; Liwu Lin

    2003-01-01

    The kinetics of CO hydrogenation for the synthesis of C2 oxygenates over Rh-Mn-Li-Fe/SiO2was investigated. Kinetic parameters for the formation of ethanol, acetaldehyde, C2 oxygenates, methanol and methane were obtained. The activation energy, H2 and CO dependence orders for ethanol and acetaldehyde formation differed greatly, the large difference seemed to imply that they were formed through different intermediates.

  6. Effects of 20 Selected Fruits on Ethanol Metabolism: Potential Health Benefits and Harmful Impacts

    OpenAIRE

    Zhang, Yu-Jie; Wang, Fang; Zhou, Yue; Li, Ya; Zhou, Tong; Zheng, Jie; Zhang, Jiao-jiao; Li, Sha; Xu, Dong-Ping; Li, Hua-Bin

    2016-01-01

    The consumption of alcohol is often accompanied by other foods, such as fruits and vegetables. This study is aimed to investigate the effects of 20 selected fruits on ethanol metabolism to find out their potential health benefits and harmful impacts. The effects of the fruits on ethanol metabolism were characterized by the concentrations of ethanol and acetaldehyde in blood, as well as activities of alcohol dehydrogenase and acetaldehyde dehydrogenase in liver of mice. Furthermore, potential ...

  7. Quantitative DEMS study of ethanol oxidation: effect of surface structure and Sn surface modification.

    Science.gov (United States)

    Mostafa, Ehab; Abd-El-Latif, Abd-El-Aziz A; Ilsley, Richard; Attard, Gary; Baltruschat, Helmut

    2012-12-14

    Using the dual thin layer flow through cell, a semi-quantitative analysis of the volatile products during the electrooxidation of adsorbed and bulk solution of 0.01 M ethanol at polycrystalline platinum, smooth, roughened and Sn modified Pt(11,1,1), Pt(311) electrodes has been done by on-line differential electrochemical mass spectroscopy (DEMS). In addition to the current efficiency of CO(2), that of acetaldehyde was determined as a function of the flow rate. At polycrystalline platinum, ethanol oxidation produces only acetaldehyde; the amount of acetaldehyde further oxidized to acetic acid is negligible due to convection conditions. For comparison and for calibration purposes, i-propanol oxidation was examined for which acetone is the only oxidation product. At Pt(11,1,1), the main oxidation product is acetaldehyde. At Pt(311), in addition to acetaldehyde, acetic acid was also formed. Surface modification with Sn did not increase the reactivity of Pt(11,1,1) instead it led to inhibition of the ethanol oxidation. In the case of Pt(311), the onset potential of oxidation was shifted negatively by 0.2 V in the presence of Sn. The results of the potentiostatic measurements showed that this shift is not associated with the production of CO(2); rather acetic acid and acetaldehyde are the main oxidation products. PMID:23108295

  8. Hypothesis of demodicidosis rosacea flushing etiopathogenesis.

    Science.gov (United States)

    Robledo, Mary Ann; Orduz, Mariana

    2015-04-01

    Most of the patients with erythematotelangiectatic rosacea are characterized by flushing, oedema and telangiectasia. The etiopathogenesis of the flushing in rosacea patients is unknown. Clinically the flushing in rosacea is similar to the "Asian flushing syndrome". Most Asians have an overactive alcohol dehydrogenase (ADH) that tends to break down alcohol into acetaldehyde faster. People with "Asians flushing syndrome" have a genetic disorder with the Aldehyde Dehydrogenase 2(∗)2 (ALDH2(∗)2) allele. This is the reason why they do not metabolize very well the acetaldehyde that comes from the alcohol, which means that acetaldehyde takes much longer to clear from their blood. ALDH2 enzyme is primarily responsible for oxidation of acetaldehyde derived from ethanol metabolism, as well as oxidation of various other endogenous and exogenous aldehydes. Acetaldehyde produces the vasodilatation in the "Asian flushing syndrome". The antibodies against the GroEl chaperonin protein, a 62-kDa heat shock protein were found in the Bacillus oleronius isolated from Demodex mites, in rosacea patients. The GroEl chaperonin protein is a protein that plays a key role in normal folding of ALDH2. If the GroEl chaperonin antibodies found in patients with rosacea, cross react with the human GroEl chaperonin protein, they will not fold normally the ALDH2, and then the enzyme will not metabolize the acetaldehyde. Many of the patients with rosacea have a concomitant infection with Helicobacter pylori in their stomach. The H.pylori produces high amounts of acetaldehyde, which comes from their metabolism of ethanol or carbohydrates. As a result, high amounts of acetaldehyde will circulate for longer time in the blood, until the liver CYP2E1(p450) enzyme system finally metabilizes the acetaldehyde, during that period of time the patients will experience a flushing as well as the people with the "Asian flushing syndrome" suffer when they drink ethanol. To prove the hypothesis it is necessary

  9. Deuterium D(V/K) isotope effects on ethanol oxidation in hepatocytes; Importance of the reverse ADH-reaction

    Energy Technology Data Exchange (ETDEWEB)

    Lundquist, F.; Iversen, H.L.; Hansen, L.L. (Department of Biochemistry A, The Panum Institute, University of Copenhagen (Denmark))

    1990-01-01

    The kinetic deuterium isotope effect, D(V/K), on ethanol oxidation was measured on hepatocytes from rat and pig by the radiometric competitive method using {sup 14}C-labelled ethanol containing deuterium in the (a-R)-position. The corrected D(V/K) values of 2.68 and 2.80 for rat and pig hepatocytes respectively were significantly different, suggesting differences in the amount of non-ADH ethanol oxidizing activity. The apparent isotope effects declined repidly with time when acetaldehyde was present in the medium as a result of the reduction to ethanol of the ({sup 14}C)-acetaldehyde formed from the double labelled ethanol by alcohol dehydrogenase (ADH). Fructose and cynamide caused the acetaldehyde concentration during ethanol oxidation to increase by entirely different mechanisms, and the isotope effect to decrease with time, as did also the addition of acetaldehyde. The apparent first order rate constant for the reverse ADH reaction, assuming the reactants to be acetaldehyde and the ADH-NADH complex, was determined by two metohods giving comparable results. In the presence of semicarbazide, which removes acetaldehyde, the isotope effect was nearly constant. This was the case also when the acetaldehyde concentration was very low (<1 {mu}M) for other reasons, as in hepatocytes from starved animals. A mathematical formula describing the expected decrease of the apparent isotope effect with time was derived. The different response of pig and rat hepatocytes to addition of fructose (the 'fructose effect') is suggested to be caused by differences in activity of aldehyde dehydrogenases in the two species. (author).

  10. Ambient concentrations of aldehydes in relation to Beijing Olympic air pollution control measures

    Science.gov (United States)

    Gong, J. C.; Zhu, T.; Hu, M.; Zhang, L. W.; Cheng, H.; Zhang, L.; Tong, J.; Zhang, J.

    2010-08-01

    Aldehydes are ubiquitous constituents of the atmosphere. Their concentrations are elevated in polluted urban atmospheres. The present study was carried out to characterize three aldehydes of most health concern (formaldehyde, acetaldehyde, and acrolein) in a central Beijing site in the summer and early fall of 2008 (from June to October). Measurements were made before, during, and after the Beijing Olympics to examine whether the air pollution control measures implemented to improve Beijing's air quality during the Olympics had any impact on concentrations of the three aldehydes. Average concentrations of formaldehyde, acetaldehyde and acrolein were 29.34 ± 15.12 μg/m3, 27.09 ± 15.74 μg/m3 and 2.32 ± 0.95 μg/m3, respectively, for the entire period of measurements, all being the highest among the levels measured in cities around the world in photochemical smog seasons. Among the three measured aldehydes, only acetaldehyde had a substantially reduced mean concentration during the Olympic air pollution control period compared to the pre-Olympic period. Formaldehyde and acrolein followed the changing pattern of temperature and were each significantly correlated with ozone (a secondary product of photochemical reactions). In contrast, acetaldehyde was significantly correlated with several pollutants emitted mainly from local emission sources (e.g., NO2, CO, and PM2.5). These findings suggest that local direct emissions had a larger impact on acetaldehyde than formaldehyde and acrolein.

  11. Alternate fuels and chemicals from synthesis gas: Vinyl acetate monomer. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Richard D. Colberg; Nick A. Collins; Edwin F. Holcombe; Gerald C. Tustin; Joseph R. Zoeller

    1999-01-01

    There has been a long-standing desire on the part of industry and the U.S. Department of Energy to replace the existing ethylene-based vinyl acetate monomer (VAM) process with an entirely synthesis gas-based process. Although there are a large number of process options for the conversion of synthesis gas to VAM, Eastman Chemical Company undertook an analytical approach, based on known chemical and economic principles, to reduce the potential candidate processes to a select group of eight processes. The critical technologies that would be required for these routes were: (1) the esterification of acetaldehyde (AcH) with ketene to generate VAM, (2) the hydrogenation of ketene to acetaldehyde, (3) the hydrogenation of acetic acid to acetaldehyde, and (4) the reductive carbonylation of methanol to acetaldehyde. This report describes the selection process for the candidate processes, the successful development of the key technologies, and the economic assessments for the preferred routes. In addition, improvements in the conversion of acetic anhydride and acetaldehyde to VAM are discussed. The conclusion from this study is that, with the technology developed in this study, VAM may be produced from synthesis gas, but the cost of production is about 15% higher than the conventional oxidative acetoxylation of ethylene, primarily due to higher capital associated with the synthesis gas-based processes.

  12. Evidence for the formation of an enamine species during aldol and Michael-type addition reactions promiscuously catalyzed by 4-oxalocrotonate tautomerase.

    Science.gov (United States)

    Poddar, Harshwardhan; Rahimi, Mehran; Geertsema, Edzard M; Thunnissen, Andy-Mark W H; Poelarends, Gerrit J

    2015-03-23

    The enzyme 4-oxalocrotonate tautomerase (4-OT), which has a catalytic N-terminal proline residue (Pro1), can promiscuously catalyze various carbon-carbon bond-forming reactions, including aldol condensation of acetaldehyde with benzaldehyde to yield cinnamaldehyde, and Michael-type addition of acetaldehyde to a wide variety of nitroalkenes to yield valuable γ-nitroaldehydes. To gain insight into how 4-OT catalyzes these unnatural reactions, we carried out exchange studies in D2 O, and X-ray crystallography studies. The former established that H-D exchange within acetaldehyde is catalyzed by 4-OT and that the Pro1 residue is crucial for this activity. The latter showed that Pro1 of 4-OT had reacted with acetaldehyde to give an enamine species. These results provide evidence of the mechanism of the 4-OT-catalyzed aldol and Michael-type addition reactions in which acetaldehyde is activated for nucleophilic addition by Pro1-dependent formation of an enamine intermediate. PMID:25728471

  13. Gas sensing properties of graphene–WO{sub 3} composites prepared by hydrothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Xiangfeng, E-mail: xfchu99@ahut.edu.cn [School of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan 243002 (China); Hu, Tao [School of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan 243002 (China); Gao, Feng [Department of Materials Science and Engineering, Nanjing University, Nanjing 210093 (China); Dong, Yongping; Sun, Wenqi; Bai, Linshan [School of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan 243002 (China)

    2015-03-15

    Graphical abstract: - Highlights: • The amount of graphene had an effect on the morphology of graphene–WO{sub 3} composites. • The optimum temperature of 0.1 wt% graphene–WO{sub 3} sensor to acetaldehyde was 100 °C. • 0.1 wt% graphene–WO{sub 3} sensor exhibited good selectivity to acetaldehyde at 100 °C. - Abstract: Graphene–WO{sub 3} composites mixed with different amounts of graphene (0, 0.1, 0.5, 1 and 3 wt%) were prepared by hydrothermal method at 180 °C for 24 h. The as-prepared graphite oxide, graphene and graphene–WO{sub 3} composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectra (FT-IR) and Raman spectroscopy, respectively. The effect of the amount of graphene in the composites on the gas-sensing responses and the gas-sensing selectivity of the materials was investigated. The experimental results revealed that the sensor based on 0.1 wt% graphene–WO{sub 3} composite exhibited high response and good selectivity to acetaldehyde vapor at 100 °C, the optimum operating temperature of this sensor to 1000 ppm acetaldehyde vapor decreased from 180 °C to 100 °C comparing with that of pure WO{sub 3}. The response time and the recovery time for 100 ppm acetaldehyde vapor were 250 s and 225 s, respectively.

  14. Modulation of ethanol-induced conditioned place preference in mice by 3-amino-1,2,4-triazole and D-penicillamine depends on ethanol dose and number of conditioning trials.

    Science.gov (United States)

    Ledesma, Juan Carlos; Font, Laura; Baliño, Pablo; Aragon, Carlos M G

    2013-12-01

    Previous studies have shown that both 3-amino-1,2,4-triazole (AT), which inhibits metabolism of ethanol (EtOH) to acetaldehyde by inhibiting catalase, and D-penicillamine (D-P), an acetaldehyde-sequestering agent, modulate EtOH-conditioned place preference (CPP) in male albino Swiss (IOPS Orl) mice. These studies followed a reference-dose-like procedure, which involves comparing cues that have both been paired with EtOH. However, the role of EtOH-derived acetaldehyde has not been examined using a standard CPP method, and efficacy of these treatments could be different under the two circumstances. In the present investigation, we manipulated the strength of CPP across five separate studies and evaluated the effect of D-P and AT on EtOH-induced CPP following a standard unbiased CPP procedure. Mice received pairings with vehicle-saline injections with one cue and, alternatively, with AT- and D-P-EtOH with another cue. Our studies indicate that AT and D-P only disrupt CPP induced by EtOH in mice when the number of conditioning sessions and the dose of EtOH are low. These findings suggest that acquisition of EtOH-induced CPP may depend on the levels of acetaldehyde available during memory acquisition and the strength of the memory. Therefore, we propose that, at least when the memory processes are labile, brain acetaldehyde could participate in the formation of Pavlovian learning elicited by EtOH.

  15. Temporal variation of carbonyl compound concentrations at a semi-rural site in Denmark

    DEFF Research Database (Denmark)

    Christensen, C.S.; Skov, H.; Nielsen, T.;

    2000-01-01

    The atmospheric concentrations of formaldehyde, acetaldehyde and acetone were measured by the DNPH-technique at the semi-rural site Lille Valby, Denmark (55 degrees N) between May-July 1995, The average concentrations were observed to be 1.2 ppbv for formaldehyde, 0.8 ppbv for acetaldehyde and 1.......9 ppbv for acetone, For the set of carbonyl compounds, concentrations were found to be highly correlated, though only during daytime, The weak correlations observed during nighttime are believed to be caused by the dry deposition of especially formaldehyde, During periods with low photochemical activity...... of hydrocarbons during long-range transport. Especially, the concentration levels of acetone showed a pronounced seasonal-variation with the highest levels observed during summertime and lowest in winter and spring. The seasonal variation in the concentration levels of formaldehyde and acetaldehyde were small...

  16. On-road emissions of carbonyls from vehicles powered by biofuel blends in traffic tunnels in the Metropolitan Area of Sao Paulo, Brazil

    Science.gov (United States)

    Nogueira, Thiago; Souza, Kely Ferreira de; Fornaro, Adalgiza; Andrade, Maria de Fatima; Carvalho, Lilian Rothschild Franco de

    2015-05-01

    On-road emissions of carbonyls from the current vehicle fleet of Brazil were determined in two experimental campaigns, conducted in traffic tunnels located in the Metropolitan Area of São Paulo (MASP), in southeastern Brazil. Among carbonyl species, formaldehyde and acetaldehyde were the most abundant in all sampling periods. In Brazil, heavy-duty vehicles (HDVs) run on a blend of 95% regular diesel/5% biodiesel from soy, whereas light-duty vehicles (LDVs) run on gasohol (75-80% gasoline/20-25% ethanol) or hydrous ethanol. We found that HDVs showed the highest overall carbonyl emissions, although LDVs were responsible for high emissions of acetaldehyde. In comparison with LDVs in California, which are powered by 90% gasoline/10% ethanol, LDVs in Brazil were found to emit 352% and 263% more formaldehyde and acetaldehyde.

  17. Endogenous ethanol--its metabolic, behavioral and biomedical significance.

    Science.gov (United States)

    Ostrovsky YuM

    1986-01-01

    Ethanol is constantly formed endogenously from acetaldehyde, and level of the former can be measured in both human beings and animals. Acetaldehyde can be generated in situ from the metabolism of pyruvate, threonine, deoxyribose-5-phosphate, phosphoethanolamine, alanine and presumably from other substrates. The levels of blood and tissue endogenous ethanol change as a function of various physiologic and experimental conditions such as starvation, aging, stress, cooling, adrenalectomy, etc. and are regulated by many exogenous compounds such as antimetabolites, derivatives of amino acids, lithium salts, disulfiram, cyanamide, etc. Under free choice alcohol selection situations, the levels of endogenous ethanol in rat blood and alcohol preference by the animals are negatively correlated. Similar negative correlations have been found between the levels of blood endogenous ethanol and the frequency of delirium in alcoholic patients undergoing alcohol withdrawal. Endogenous ethanol and acetaldehyde can therefore be regarded as compounds which fulfil substrate, regulatory and modulator functions.

  18. Kinetic modeling of aldehyde adsorption rates on bare and aminopropylsilyl-modified silica gels by ultra-rapid-scanning fourier transform infrared spectrometry.

    Science.gov (United States)

    Yang, Husheng; Weinstock, Benjamin A; Hirsche, Blayne L; Griffiths, Peter R

    2005-04-26

    Enhancements of a model capable of precisely defining rates of adsorption in terms of a Langmuir isotherm and determined from infrared and pressure data collected in the millisecond time regime are described in detail. Rates of adsorption are determined for formaldehyde and acetaldehyde exposed to bare and aminopropylsilyl-derivatized silica gel. The model fits the collected data by varying the number of adsorption sites and the adsorption and desorption rate constants and determines the best fit based on the measured IR absorbance, partial pressure, exposure backpressure, number of adsorption sites, and time. The rate of adsorption onto irregular-shaped silica gel was faster than the rate onto the corresponding spherical silica gel. Formaldehyde was adsorbed more efficiently than acetaldehyde on APS silica gel than on bare silica gel, whereas acetaldehyde was adsorbed more efficiently than formaldehyde on underivatized silica, indicating the possibility that formaldehyde is adsorbed through the formation of a Schiff base.

  19. Alcohol metabolism by oral streptococci and interaction with human papillomavirus leads to malignant transformation of oral keratinocytes.

    Science.gov (United States)

    Tao, Lin; Pavlova, Sylvia I; Gasparovich, Stephen R; Jin, Ling; Schwartz, Joel

    2015-01-01

    Poor oral hygiene, ethanol consumption, and human papillomavirus (HPV) are associated with oral and esophageal cancers. However, the mechanism is not fully known. This study examines alcohol metabolism in Streptococcus and its interaction with HPV-16 in the malignant transformation of oral keratinocytes. The acetaldehyde-producing strain Streptococcus gordonii V2016 was analyzed for adh genes and activities of alcohol and aldehyde dehydrogenases. Streptococcus attachment to immortalized HPV-16 infected human oral keratinocytes, HOK (HPV/HOK-16B), human oral buccal keratinocytes, and foreskin keratinocytes was studied. Acetaldehyde, malondialdehyde, DNA damage, and abnormal proliferation among keratinocytes were also quantified. We found that S. gordonii V2016 expressed three primary alcohol dehydrogenases, AdhA, AdhB, and AdhE, which all oxidize ethanol to acetaldehyde, but their preferred substrates were 1-propanol, 1-butanol, and ethanol, respectively. S. gordonii V2016 did not show a detectable aldehyde dehydrogenase. AdhE is the major alcohol dehydrogenase in S. gordonii. Acetaldehyde and malondialdehyde production from permissible Streptococcus species significantly increased the bacterial attachment to keratinocytes, which was associated with an enhanced expression of furin to facilitate HPV infection and several malignant phenotypes including acetaldehyde adduct formation, abnormal proliferation, and enhanced migration through integrin-coated basement membrane by HPV-infected oral keratinocytes. Therefore, expression of multiple alcohol dehydrogenases with no functional aldehyde dehydrogenase contributes to excessive production of acetaldehyde from ethanol by oral streptococci. Oral Streptococcus species and HPV may cooperate to transform oral keratinocytes after ethanol exposure. These results suggest a significant clinical interaction, but further validation is warranted.

  20. Nickel and cobalt as active phase on supported zirconia catalysts for bio-ethanol reforming: Influence of the reaction mechanism on catalysts performance

    Energy Technology Data Exchange (ETDEWEB)

    Padilla, R.; Rodriguez, L.; Serrano, A.; Munoz, G. [Instituto de Catalisis y Petroleoquimica (CSIC), C/ Marie Curie 2, Campus Cantoblanco, 28049 Madrid (Spain); Benito, M.; Daza, L. [Instituto de Catalisis y Petroleoquimica (CSIC), C/ Marie Curie 2, Campus Cantoblanco, 28049 Madrid (Spain); Centro de Investigaciones Energeticas Medioambientales y Tecnologicas (CIEMAT), Av. Complutense 22, 28040 Madrid (Spain)

    2010-09-15

    Steam reforming of ethanol for hydrogen production was investigated on Co/ZrO{sub 2} and Ni/ZrO{sub 2} catalysts promoted with lanthana. Catalysts were prepared by impregnation method and characterized by XRD and TPR. TPD-R experiments were also carried out to determine the role of active phase on reaction mechanism. The results suggest that adsorbed ethanol is dehydrogenated to acetaldehyde producing hydrogen. Then, the adsorbed acetaldehyde may evolve by different mechanisms, depending on the nature of active phase. On one hand, in cobalt-based catalyst, acetaldehyde could be reformed directly. By acetaldehyde thermal decomposition, methyl and formaldehyde groups are obtained. By coupling of methyl groups, ethane can be obtained. At medium temperature range, WGS reaction contribution is noteworthy. On the other hand, in nickel-based catalyst, acetone was detected in a higher temperature range as the main intermediate reaction product, which indicates that acetaldehyde is transformed into acetone by decarbonylation of acetaldehyde leading to H{sub 2} and CO{sub 2} formation. In addition, acetone can also be reformed to give both H{sub 2} and CO{sub 2}. Contrary to cobalt-based catalyst, ethylene was detected at intermediate range temperature which suggests that it was formed by ethanol dehydration reaction. Ethylene polymerization could easily explain coke formation, which must be avoided. Steam reforming reaction was studied at S/C ratio of 4.84 and 700 C, to verify the activity, selectivity and stability of the catalysts. Ethanol conversion reached 100% and catalysts were very stable for almost 50 h on stream. No significant differences were detected in both catalysts. Nevertheless, TPO experiments performed on used samples demonstrate a higher carbon production on nickel based catalyst that can be correlated to ethanol dehydration contribution on it reaction pathway. (author)

  1. Alcohol metabolism in human cells causes DNA damage and activates the Fanconi anemia – breast cancer susceptibility (FA-BRCA) DNA damage response network

    Science.gov (United States)

    Abraham, Jessy; Balbo, Silvia; Crabb, David; Brooks, P.J.

    2011-01-01

    Background We recently reported that exposure of human cells in vitro to acetaldehyde resulted in activation of the Fanconi anemia-breast cancer associated (FA-BRCA) DNA damage response network. Methods To determine whether intracellular generation of acetaldehyde from ethanol metabolism can cause DNA damage and activate the FA-BRCA network, we engineered HeLa cells to metabolize alcohol by expression of human alcohol dehydrogenase 1B. Results Incubation of HeLa-ADH1B cells with ethanol (20 mM) resulted in acetaldehyde accumulation in the media which was prevented by co-incubation with 4-methyl pyrazole (4-MP), a specific inhibitor of ADH. Ethanol treatment of HeLa-ADH1B cells produced a 4-fold increase in the acetaldehyde-DNA adduct, N2-ethylidene-dGuo, and also resulted in activation of the Fanconi anemia -breast cancer susceptibility (FA-BRCA) DNA damage response network, as indicated by a monoubiquitination of FANCD2, and phosphorylation of BRCA1. Ser 1524 was identified as one site of BRCA1 phosphorylation. The increased levels of DNA adducts, FANCD2 monoubiquitination, and BRCA1 phosphorylation were all blocked by 4-MP, indicating that acetaldehyde, rather than ethanol itself, was responsible for all three responses. Importantly, the ethanol concentration we used is within the range that can be attained in the human body during social drinking. Conclusions Our results indicate that intracellular metabolism of ethanol to acetaldehyde results in DNA damage which activates the FA-BRCA DNA damage response network. PMID:21919919

  2. Isolated tumoral pyruvate dehydrogenase can synthesize acetoin which inhibits pyruvate oxidation as well as other aldehydes.

    Science.gov (United States)

    Baggetto, L G; Lehninger, A L

    1987-05-29

    Oxidation of 1 mM pyruvate by Ehrlich and AS30-D tumor mitochondria is inhibited by acetoin, an unusual and important metabolite of pyruvate utilization by cancer cells, by acetaldehyde, methylglyoxal and excess pyruvate. The respiratory inhibition is reversed by other substrates added to pyruvate and also by 0.5 mM ATP. Kinetic properties of pyruvate dehydrogenase complex isolated from these tumor mitochondria have been studied. This complex appears to be able to synthesize acetoin from acetaldehyde plus pyruvate and is competitively inhibited by acetoin. The role of a new regulatory pattern for tumoral pyruvate dehydrogenase is presented.

  3. Computational fluid dynamics simulation of ethanol steam reforming in catalytic wall microchannels

    OpenAIRE

    Uriz, I.; Arzamendi, G.; López, E.; Llorca Piqué, Jordi; Gandía, L.M.

    2011-01-01

    A three-dimensional computational fluid dynamics (CFD) simulation study of the ethanol steam reforming (ESR) in microreactors with square channels has been carried out. A phenomenological kinetic model describing the ESR on a Co3O4–ZnO catalyst has been established and implemented in the CFD codes. This model includes the ethanol dehydrogenation to acetaldehyde, ethanol decomposition to CO and CH4, acetaldehyde steam reforming to H2 and CO2 and water–gas shift as the reactions des...

  4. Dynamic modeling of a three-stage low-temperature ethanol reformer for fuel cell application

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Vanesa M.; Serra, Maria [Institut de Robotica i Informatica Industrial (CSIC-UPC), Llorens i Artigas 4-6, 08028 Barcelona (Spain); Lopez, Eduardo; Llorca, Jordi [Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, ed. ETSEIB, 08028 Barcelona (Spain)

    2009-07-01

    A low-temperature ethanol reformer based on a cobalt catalyst for the production of hydrogen has been designed aiming the feed of a fuel cell for an autonomous low-scale power production unit. The reformer comprises three stages: ethanol dehydrogenation to acetaldehyde and hydrogen over SnO{sub 2} followed by acetaldehyde steam reforming over Co(Fe)/ZnO catalyst and water gas shift reaction. Kinetic data have been obtained under different experimental conditions and a dynamic model has been developed for a tubular reformer loaded with catalytic monoliths for the production of the hydrogen required to feed a 1 kW PEMFC. (author)

  5. Thermal decomposition of ethylene oxide on Pd(111). Comparison of the pathways for the selective oxidation of ethylene and olefin metathesis

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, R.M. (Univ. of Cambridge (United Kingdom)); Ormerod, R.M. (Univ. of Keele (United Kingdom)); Tysoe, W.T. (Univ. of Wisconsin, Milwaukee, WI (United States))

    1994-03-01

    The product distribution detected in the multimass temperature-programmed desorption of a saturated overlayer of ethylene oxide adsorbed on Pd(111) at [approximately] 180 K indicates that it decomposes to yield ethylene and acetaldehyde. These observations are interpreted by postulating that ethylene oxide reacts to form an oxymetallocycle. This is proposed to thermally decompose in a manner analogous to carbometallocycles that form during olefin metathesis catalysis by the reaction between an alkene and a surface carbene. Thus, the metallocycle can decompose to yield ethylene and deposit adsorbed atomic oxygen or undergo a [beta]-hydrogen transfer to form acetaldehyde. 25 refs., 2 figs., 1 tab.

  6. Isolated tumoral pyruvate dehydrogenase can synthesize acetoin which inhibits pyruvate oxidation as well as other aldehydes.

    Science.gov (United States)

    Baggetto, L G; Lehninger, A L

    1987-05-29

    Oxidation of 1 mM pyruvate by Ehrlich and AS30-D tumor mitochondria is inhibited by acetoin, an unusual and important metabolite of pyruvate utilization by cancer cells, by acetaldehyde, methylglyoxal and excess pyruvate. The respiratory inhibition is reversed by other substrates added to pyruvate and also by 0.5 mM ATP. Kinetic properties of pyruvate dehydrogenase complex isolated from these tumor mitochondria have been studied. This complex appears to be able to synthesize acetoin from acetaldehyde plus pyruvate and is competitively inhibited by acetoin. The role of a new regulatory pattern for tumoral pyruvate dehydrogenase is presented. PMID:3593337

  7. Vapor-liquid equilibria of trace isobutyraldehyde, ethyl acetate and isoamyl acetate in aqueous ethanol solution under reduced pressure; Ethanol suiyoekichu no biryo no isobutyraldehyde, sakusan ethyl, sakusan isoamyl no gen`atsu kieki heiko

    Energy Technology Data Exchange (ETDEWEB)

    Ikari, A.; Hatate, Y.; Aiko, R. [Kagoshima University, Kagoshima (Japan)

    1997-07-10

    Vapor-liquid equilibria of aqueous ethanol solutions containing a minute amount of acetaldehyde, isobutyraldehyde, ethyl acetate and isoamyl acetate were measured by use of an Othmer-type still at 12.7, 25.3 and 101.3 kPa. The equilibrium ratio curves of the minor components (isobutyraldehyde, ethyl acetate and isoamyl acetate) at each pressure are presented by a function of the concentration of ethanol. However, the equilibrium ratio curves of the minor component (acetaldehyde) could not be obtained, because the data is slightly scatted. 5 refs., 3 figs., 2 tabs.

  8. Multi-enzyme catalyzed rapid ethanol lowering in vitro.

    Science.gov (United States)

    Whitmire, D R; Chambers, R P; Dillon, A R

    1991-10-01

    Ethanol was oxidized to acetate by an enzyme system using yeast alcohol dehydrogenase (YADH), yeast aldehyde dehydrogenase (YALDH), and lactic dehydrogenase (LDH) recycling NAD in two model duodenal fluids and in canine duodenal aspirate in vitro. Sufficient enzyme activities were maintained to convert as much as 34% of the original ethanol to acetate with negligible acetaldehyde accumulation.

  9. Emissions and photochemistry of oxygenated VOCs in urban plumes in the Northeastern United States

    Directory of Open Access Journals (Sweden)

    R. Sommariva

    2011-07-01

    Full Text Available Photochemical processes inside urban plumes in the Northeast of the United States have been studied using a highly detailed chemical model, based upon the Master Chemical Mechanism (MCM. The model results have been compared to measurements of oxygenated VOCs (acetone, methyl ethyl ketone, acetaldehyde, acetic acid and methanol obtained during several flights of the NOAA WP-3D aircraft, which sampled plumes from the New York City area during the ICARTT campaign in 2004. The agreement between the model and the measurements was within 40–60 % for all species, except acetic acid.

    The model results have been used to study the formation and photochemical evolution of acetone, methyl ethyl ketone and acetaldehyde. Under the conditions encountered during the ICARTT campaign, acetone is produced from the oxidation of propane (24–28 % and i-propanol (<15 % and from a number of products of i-pentane oxidation. Methyl ethyl ketone (MEK is mostly produced from the oxidation of n-butane (20–30 % and 3-methylpentane (<40 %. Acetaldehyde is formed from several precursors, mostly small alkenes, >C5 alkanes, propanal and MEK. Ethane and ethanol oxidation account, respectively, for 6–23 % and 5–25 % of acetaldehyde photochemical formation. The results highlight the importance of alkanes for the photochemical production of ketones and the role of hydroperoxides in sustaining their formation far from the emission sources.

  10. Gas-Phase Oxidation of Aqueous Ethanol by Nanoparticle Vanadia/Anatase Catalysts

    DEFF Research Database (Denmark)

    Jørgensen, Betina; Kristensen, Steffen Buus; Kunov-Kruse, Andreas Jonas;

    2009-01-01

    The gas-phase oxidation of aqueous ethanol with dioxygen has been examined with a new nanoparticle V2O5/TiO2 catalyst. Product selectivity could to a large extent be controlled by small alterations of reaction parameters, allowing production of acetaldehyde at a selectivity higher than 90%, near...

  11. Guide On Analysis Of Dangerous And Harmful Object

    International Nuclear Information System (INIS)

    This book lists the dangerous and harmful object, which are Acetaldehyde, Acetic acid, Acetone, Acrolein, Aldrin Ammonia, Arsenic, Asphalt, Barium, Benzene, Benzyl chloride, Butane, Butylamine, Butyl mercaptan, Cadmium, Cadmium chloride, Cadmium nitrate, Cadmium sulfate, Calcium, Calcium carbonate, Calcium chloride, Calcium cyanamide, Calcium oxide, Captan, Carbon black, Carbon dioxide, Carbon disulfide, Catechol, Chlordane, Chlorine, Chlorine dioxide, Chlorine trifluoride and Chloroacetic acid.

  12. 40 CFR 261.32 - Hazardous wastes from specific sources.

    Science.gov (United States)

    2010-07-01

    ... residues from coal tar refining (T) K148 Residues from coal tar distillation, including but not limited to...) K004 Wastewater treatment sludge from the production of zinc yellow pigments (T) K005 Wastewater... pigments (T) Organic chemicals: K009 Distillation bottoms from the production of acetaldehyde from...

  13. Principal component analysis of UV-VIS-NIR transmission spectra of Moldavian matured wine distillates

    Science.gov (United States)

    Khodasevich, Mikhail A.; Trofimova, Darya V.; Nezalzova, Elena I.

    2011-02-01

    Principal component analysis of UV-VIS-NIR transmission spectra of matured wine distillates (1-40 years aged) produced by three Moldavian manufacturers allows to characterize with sufficient certainty the eleven chemical parameters of considered alcoholic beverages: contents of acetaldehyde, ethyl acetate, furfural, vanillin, syringic aldehyde and acid, etc.

  14. Alcohol intake and ovarian cancer risk : A pooled analysis of 10 cohort studies

    NARCIS (Netherlands)

    Genkinger, J.M.; Hunter, D.J.; Spiegelman, D.; Anderson, K.E.; Buring, J.E.; Freudenheim, J.L.; Goldbohm, R.A.; Harnack, L.; Hankinson, S.E.; Larsson, S.C.; Leitzmann, M.; McCullough, M.L.; Marshall, J.; Miller, A.B.; Rodriguez, C.; Rohan, T.E.; Schatzkin, A.; Schouten, L.J.; Wolk, A.; Zhang, S.M.; Smith-Warner, S.A.

    2006-01-01

    Alcohol has been hypothesized to promote ovarian carcinogenesis by its potential to increase circulating levels of estrogen and other hormones; through its oxidation byproduct, acetaldehyde, which may act as a cocarcinogen; and by depletion of folate and other nutrients. Case-control and cohort stud

  15. Oxidation of Bioethanol using Zeolite-Encapsulated Gold Nanoparticles

    DEFF Research Database (Denmark)

    Mielby, Jerrik Jørgen; Abildstrøm, Jacob Oskar; Wang, Feng;

    2014-01-01

    With the ongoing developments in biomass conversion, the oxidation of bioethanol to acetaldehyde may become a favorable and green alternative to the preparation from ethylene. Here, a simple and effective method to encapsulate gold nanoparticles in zeolite silicalite-1 is reported and their high...

  16. Oxidation of Bioethanol using Zeolite-Encapsulated Gold Nanoparticles

    DEFF Research Database (Denmark)

    Mielby, Jerrik Jørgen; Abildstrøm, Jacob Oskar; Wang, Feng;

    2014-01-01

    With the ongoing developments in biomass conversion, the oxidation of bioethanol to acetaldehyde may become a favorable and green alternative to the preparation from ethylene. Here, a simple and effective method to encapsulate gold nanoparticles in zeolite silicalite‐1 is reported and their high...

  17. Reflections on the aerobic fermentation stoichiometry of crabtree positive yeasts

    DEFF Research Database (Denmark)

    Villadsen, John; Jørgensen, Sten Bay

    2014-01-01

    in the model of Sonnleitner and Käppeli, 1986 shrinks abruptly at Dcrit and continues to decrease with increasing dilution rate. A black box stoichiometric analysis of experiments reported in literature indicates that production of acetaldehyde might account for the abrupt shrinkage through a severe poisoning...

  18. 40 CFR 80.90 - Conventional gasoline baseline emissions determination.

    Science.gov (United States)

    2010-07-01

    ... benzene, formaldehyde, acetaldehyde, 1,3-butadiene, and polycyclic organic matter shall be determined... benzene emissions, exhaust toxics emissions, NOX emissions, sulfur, olefins and T90 shall be determined... determined to four (4) significant figures. Sulfur, olefin and T90 values calculated per the requirements...

  19. 40 CFR Table 8 to Subpart Ggg of... - Fraction Measured (Fm) for HAP Compounds in Wastewater Streams

    Science.gov (United States)

    2010-07-01

    ... Compounds in Wastewater Streams 8 Table 8 to Subpart GGG of Part 63 Protection of Environment ENVIRONMENTAL... Streams Chemical name CAS No. a Fm Acetaldehyde 75070 1.00 Acetonitrile 75058 0.99 Acetophenone 98862 0.31 Acrolein 107028 1.00 Acrylonitrile 107131 1.00 Allyl chloride 107051 1.00 Benzene 71432 1.00...

  20. 46 CFR 154.1720 - Indirect refrigeration.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Indirect refrigeration. 154.1720 Section 154.1720... § 154.1720 Indirect refrigeration. A refrigeration system that is used to cool acetaldehyde, ethylene oxide, or methyl bromide, must be an indirect refrigeration system that does not use vapor compression....

  1. Asymmetric catalytic synthesis of the proposed structure of trocheliophorolide B.

    Science.gov (United States)

    Trost, Barry M; Quintard, Adrien

    2012-09-01

    A concise catalytic asymmetric synthesis of the proposed structure of trocheliophorolide B is reported. The synthetic sequence notably features an asymmetric acetaldehyde alkynylation, a Ru-catalyzed alder-ene reaction, and a Zn-ProPhenol ynone aldol condensation. Comparison with the reported data suggests a misassignment of the natural product structure.

  2. Mass balance evaluation of alcohol emission from cattle feed

    Science.gov (United States)

    Silage on dairy farms has been recognized as an important source of volatile organic compounds (VOCs) to the atmosphere, and therefore a contributor to tropospheric ozone. Considering reactivity and likely emission rates, ethanol, 1-propanol, and acetaldehyde probably make the largest contribution t...

  3. (S)-1-[(S)-4-Benzyl-2-thioxothia­zolidin-3-yl]-3-hydroxy­butan-1-one

    OpenAIRE

    Jian-hong Yang; Cui-fen Lu; Zu-xing Chen; Gui-chun Yang

    2007-01-01

    The title compound, C14H17NO2S2, was synthesized by asymmetric aldol condensation of N-acylthiazolidinethione with acetaldehyde. In the molecule, the thiazolidine five-membered ring assumes an envelope conformation. Intermolecular C—H...O and intramolecular O—H...O and C—H...S hydrogen bonding helps to stabilize the structure.

  4. (S-1-[(S-4-Benzyl-2-thioxothiazolidin-3-yl]-3-hydroxybutan-1-one

    Directory of Open Access Journals (Sweden)

    Jian-hong Yang

    2008-01-01

    Full Text Available The title compound, C14H17NO2S2, was synthesized by asymmetric aldol condensation of N-acylthiazolidinethione with acetaldehyde. In the molecule, the thiazolidine five-membered ring assumes an envelope conformation. Intermolecular C—H...O and intramolecular O—H...O and C—H...S hydrogen bonding helps to stabilize the structure.

  5. Asymmetric catalytic synthesis of the proposed structure of trocheliophorolide B

    OpenAIRE

    Trost, Barry M.; Quintard, Adrien

    2012-01-01

    A concise catalytic asymmetric synthesis of the proposed structure of Trocheliophorolide B is reported. The synthetic sequence notably features an asymmetric acetaldehyde alkynylation, Ru-catalyzed alder-ene reaction and Zn-ProPhenol ynone aldol condensation. Comparison with the reported data suggests a miss-assignment of the natural product structure.

  6. Evidence for the Formation of an Enamine Species during Aldol and Michael-type Addition Reactions Promiscuously Catalyzed by 4-Oxalocrotonate Tautomerase

    NARCIS (Netherlands)

    Poddar, Harshwardhan; Rahimi, Mehran; Geertsema, Edzard; Thunnissen, Andy; Poelarends, Gerrit

    2015-01-01

    The enzyme 4-oxalocrotonate tautomerase (4-OT), which has a catalytic N-terminal proline residue (Pro1), can promiscuously catalyze various carbon–carbon bond-forming reactions, including aldol condensation of acetaldehyde with benzaldehyde to yield cinnamaldehyde, and Michael-type addition of aceta

  7. 77 FR 20817 - Integrated Risk Information System (IRIS); Announcement of Availability of Literature Searches...

    Science.gov (United States)

    2012-04-06

    ... AGENCY Integrated Risk Information System (IRIS); Announcement of Availability of Literature Searches for... literature searches for IRIS assessments; request for information. SUMMARY: The U.S. Environmental Protection Agency (EPA) is announcing the availability of literature searches for acetaldehyde (75-07-0) and...

  8. Color test for selective detection of secondary amines on resin and in solution

    DEFF Research Database (Denmark)

    Boas, Ulrik; Mirsharghi, Sahar

    2014-01-01

    Resins for solid-phase synthesis give orange to red-brown resin beads selectively when secondary amines are present on the resin when treated with a solution of acetaldehyde and an Fmoc-amino acid in NMP. The method shows good specificity and gives colorless beads when exposed to a variety of other...

  9. One-pot synthesis of quinaldine derivatives by using microwave irradiation without any solvent - A green chemistry approach

    Indian Academy of Sciences (India)

    Javad Safari; Sayed Hossein Banitaba; Sepehr Sadegh Samiei

    2009-07-01

    A convenient and efficient procedure for synthesis of quinaldine derivatives has been developed by a simple one-pot reaction of aniline derivatives and acetaldehyde on the surface of neutral alumina impregnated with hydrochloric acid under microwave irradiation without any solvent according to green chemistry.

  10. Emissions and photochemistry of oxygenated VOCs in urban plumes in the Northeastern United States

    Directory of Open Access Journals (Sweden)

    R. Sommariva

    2008-06-01

    Full Text Available Photochemical processes inside urban plumes in the Northeast of the United States have been studied using a highly detailed chemical model, based upon the Master Chemical Mechanism (MCM. The model results have been compared to measurements of oxygenated VOCs (acetone, methyl ethyl ketone, acetaldehyde, acetic acid and methanol obtained during several flights of the NOAA WP-3D aircraft, which sampled plumes from the New York City area during the ICARTT campaign in 2004. The agreement between the model and the measurements was within 40–60% for all species, except acetic acid.

    The model results have been used to study the formation and photochemical evolution of acetone, methyl ethyl ketone and acetaldehyde. Under the conditions encountered during the ICARTT campaign, acetone is produced from the oxidation of propane (24–28% and i-propanol (<15% and from a number of products of i-pentane oxidation. Methyl ethyl ketone (MEK is mostly produced from the oxidation of n-butane (20–30% and 3-methylpentane (<40%. Acetaldehyde is formed from several precursors, mostly small alkenes, >C5 alkanes, propanal and MEK. Ethane and ethanol oxidation account, respectively, for 6–23% and 5–25% of acetaldehyde photochemical formation. The results highlight the importance of long-chain alkanes for the photochemical production of ketones and the role of hydroperoxides in sustaining their formation far from the emission sources.

  11. [Effect of cyanamide on the level of endogenous ethanol in the liver of normal rats and in hypocorticism].

    Science.gov (United States)

    Tarasov, Iu A; Satanovskaia, V I; Shishkin, S N; Ostrovskiĭ, Iu M

    1988-01-01

    The rat liver endogenous ethanol level was found to increase under inhibition of aldehyde dehydrogenases by cyanamide. Adrenalectomy results in a decrease of the liver endogenous ethanol content and abolishes cyanamide effect on this index. One of the mechanisms of cyanamide toxic effect may be accumulation of different aldehydes including acetaldehyde.

  12. Alcohol consumption, alcohol dehydrogenase 3 polymorphism, and colorectal adenomas

    NARCIS (Netherlands)

    Tiemersma, E.W.; Wark, P.A.; Ocké, M.C.; Bunschoten, A.; Otten, M.H.; Kok, F.J.; Kampman, E.

    2003-01-01

    Alcohol is a probable risk factor with regard to colorectal neoplasm and is metabolized to the carcinogen acetaldehyde by the genetically polymorphic alcohol dehydrogenase 3 (ADH3) enzyme. We evaluated whether the association between alcohol and colorectal adenomas is modified by ADH3 polymorphism.

  13. Genes Encoding Enzymes Involved in Ethanol Metabolism

    Science.gov (United States)

    Hurley, Thomas D.; Edenberg, Howard J.

    2012-01-01

    The effects of beverage alcohol (ethanol) on the body are determined largely by the rate at which it and its main breakdown product, acetaldehyde, are metabolized after consumption. The main metabolic pathway for ethanol involves the enzymes alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). Seven different ADHs and three different ALDHs that metabolize ethanol have been identified. The genes encoding these enzymes exist in different variants (i.e., alleles), many of which differ by a single DNA building block (i.e., single nucleotide polymorphisms [SNPs]). Some of these SNPs result in enzymes with altered kinetic properties. For example, certain ADH1B and ADH1C variants that are commonly found in East Asian populations lead to more rapid ethanol breakdown and acetaldehyde accumulation in the body. Because acetaldehyde has harmful effects on the body, people carrying these alleles are less likely to drink and have a lower risk of alcohol dependence. Likewise, an ALDH2 variant with reduced activity results in acetaldehyde buildup and also has a protective effect against alcoholism. In addition to affecting drinking behaviors and risk for alcoholism, ADH and ALDH alleles impact the risk for esophageal cancer. PMID:23134050

  14. EFFECTS OF TUNGSTATE ON THE GROWTH OF DESULFOVIBRIO-GIGAS NCIMB-9332 AND OTHER SULFATE-REDUCING BACTERIA WITH ETHANOL AS A SUBSTRATE

    NARCIS (Netherlands)

    HENSGENS, CMH; NIENHUISKUIPER, ME; HANSEN, TA

    1994-01-01

    Growth of Desulfovibrio gigas NCIMB 9332 in mineral, vitamin-supplemented media with ethanol as substrate was strongly stimulated by the addition of tungstate (optimal level approximately 10(-7) M). At suboptimal tungstate concentrations, up to 1.0 mM acetaldehyde was detected in the culture superna

  15. Kinetics of acetic acid synthesis from ethanol over a Cu/SiO2 catalyst

    DEFF Research Database (Denmark)

    Voss, Bodil; Schjødt, Niels Christian; Grunwaldt, Jan-Dierk;

    2011-01-01

    . The dehydrogenation experiments were carried out in a flow through lab scale tubular reactor. Based on 71 data sets a power law kinetic expression has been derived for the description of the dehydrogenation of acetaldehyde to acetic acid. The apparent reaction order was 0.89 with respect to water and 0...

  16. Contribution of carbonyl photochemistry to aging of atmospheric secondary organic aerosol

    DEFF Research Database (Denmark)

    Mang, Stephen A.; Henricksen, Dana K.; Bateman, Adam P.;

    2008-01-01

    in situ by infrared cavity ring-down spectroscopy. A number of additional gas-phase products of SOA photodegradation were observed by gas chromatography, including methane, ethene, acetaldehyde, acetone, methanol, and I-butene. The absorption spectrum of SOA material collected onto CaF, windows was...

  17. 46 CFR Table I to Part 150 - Alphabetical List of Cargoes

    Science.gov (United States)

    2010-10-01

    ... solution 7 Glycol diacetate, see Ethylene glycol diacetate EGY Glycolic acid solution 4 GLC Glyoxal... No. Foot-note CHRIS Code Related CHRIS Codes Acetaldehyde 19 AAD Acetic acid 4 2 AAC Acetic anhydride... Acetophenone 18 ACP Acrolein 19 2 ARL Acrylamide solution 10 AAM Acrylic acid 4 2 ACR Acrylonitrile 15 2...

  18. Atmospheric ethanol in London and the potential impacts of future fuel formulations.

    Science.gov (United States)

    Dunmore, Rachel E; Whalley, Lisa K; Sherwen, Tomás; Evans, Mathew J; Heard, Dwayne E; Hopkins, James R; Lee, James D; Lewis, Alastair C; Lidster, Richard T; Rickard, Andrew R; Hamilton, Jacqueline F

    2016-07-18

    There is growing global consumption of non-fossil fuels such as ethanol made from renewable biomass. Previous studies have shown that one of the main air quality disadvantages of using ethanol blended fuels is a significant increase in the production of acetaldehyde, an unregulated and toxic pollutant. Most studies on the impacts of ethanol blended gasoline have been carried out in the US and Brazil, with much less focus on the UK and Europe. We report time resolved measurements of ethanol in London during the winter and summer of 2012. In both seasons the mean mixing ratio of ethanol was around 5 ppb, with maximum values over 30 ppb, making ethanol currently the most abundant VOC in London air. We identify a road transport related source, with 'rush-hour' peaks observed. Ethanol is strongly correlated with other road transport-related emissions, such as small aromatics and light alkanes, and has no relationship to summer biogenic emissions. To determine the impact of road transport-related ethanol emission on secondary species (i.e. acetaldehyde and ozone), we use both a chemically detailed box model (incorporating the Master Chemical Mechanism, MCM) and a global and nested regional scale chemical transport model (GEOS-Chem), on various processing time scales. Using the MCM model, only 16% of the modelled acetaldehyde was formed from ethanol oxidation. However, the model significantly underpredicts the total levels of acetaldehyde, indicating a missing primary emission source, that appears to be traffic-related. Further support for a primary emission source comes from the regional scale model simulations, where the observed concentrations of ethanol and acetaldehyde can only be reconciled with the inclusion of large primary emissions. Although only constrained by one set of observations, the regional modelling suggests a European ethanol source similar in magnitude to that of ethane (∼60 Gg per year) and greater than that of acetaldehyde (∼10 Gg per year). The

  19. Atmospheric ethanol in London and the potential impacts of future fuel formulations.

    Science.gov (United States)

    Dunmore, Rachel E; Whalley, Lisa K; Sherwen, Tomás; Evans, Mathew J; Heard, Dwayne E; Hopkins, James R; Lee, James D; Lewis, Alastair C; Lidster, Richard T; Rickard, Andrew R; Hamilton, Jacqueline F

    2016-07-18

    There is growing global consumption of non-fossil fuels such as ethanol made from renewable biomass. Previous studies have shown that one of the main air quality disadvantages of using ethanol blended fuels is a significant increase in the production of acetaldehyde, an unregulated and toxic pollutant. Most studies on the impacts of ethanol blended gasoline have been carried out in the US and Brazil, with much less focus on the UK and Europe. We report time resolved measurements of ethanol in London during the winter and summer of 2012. In both seasons the mean mixing ratio of ethanol was around 5 ppb, with maximum values over 30 ppb, making ethanol currently the most abundant VOC in London air. We identify a road transport related source, with 'rush-hour' peaks observed. Ethanol is strongly correlated with other road transport-related emissions, such as small aromatics and light alkanes, and has no relationship to summer biogenic emissions. To determine the impact of road transport-related ethanol emission on secondary species (i.e. acetaldehyde and ozone), we use both a chemically detailed box model (incorporating the Master Chemical Mechanism, MCM) and a global and nested regional scale chemical transport model (GEOS-Chem), on various processing time scales. Using the MCM model, only 16% of the modelled acetaldehyde was formed from ethanol oxidation. However, the model significantly underpredicts the total levels of acetaldehyde, indicating a missing primary emission source, that appears to be traffic-related. Further support for a primary emission source comes from the regional scale model simulations, where the observed concentrations of ethanol and acetaldehyde can only be reconciled with the inclusion of large primary emissions. Although only constrained by one set of observations, the regional modelling suggests a European ethanol source similar in magnitude to that of ethane (∼60 Gg per year) and greater than that of acetaldehyde (∼10 Gg per year). The

  20. An experimental study of extracellular signal-regulated kinase and its inter ventional treatments in hepatic ifbrosis

    Institute of Scientific and Technical Information of China (English)

    Ming-De Jiang; Shu-Mei Zheng; Hui Xu; Wei-Zheng Zeng; Yong Zhang; Hao-Ping Sun; Yun-Xia Wang; Jian-Ping Qin; Xiao-Ling Wu

    2008-01-01

    BACKGROUND:The pathogenesis of hepatic ifbrosis and cirrhosis is still not fully understood. The extracellular signal-regulated kinase (ERK) pathway is involved in the regulation of cell proliferation and differentiation. The aim of this study was to investigate the effects of PD98059, a speciifc inhibitor of ERK, on the cell cycle, cell proliferation, secretion of typeⅠcollagen and expression of cyclin D1 mRNA, CDK4 mRNA and transforming growth factor-β1 (TGF-β1) mRNA in rat hepatic stellate cells (HSCs) stimulated by acetaldehyde. METHODS:Rat HSCs stimulated by acetaldehyde were incubated with PD98059 at different concentrations. The cell cycle was analysed by lfow cytometry. Cell proliferation was assessed by the methyl thiazolyl tetrazolium colorimetric assay. The mRNA expression of cyclin D1, CDK4 and TGF-β1 was examined using the reverse transcriptase-polymerase chain reaction. Type Ⅰcollagen in the culture medium was detected by enzyme-linked immunosorbent assay. RESULTS: 20, 50 and 100 μmol/L PD98059 signiifcantly inhibited the proliferation and provoked a G0/G1-phase arrest of acetaldehyde-induced HSCs in a dose-dependent manner. The secretion of typeⅠ collagen and the expression of cyclin D1, CDK4 and TGF-β1 mRNA in acetaldehyde-induced HSCs were markedly inhibited by 50 and 100μmol/L PD98059, respectively. CONCLUSIONS:The ERK pathway regulates the cell proliferation, secretion of type Ⅰ collagen and the expression of TGF-β1 mRNA in rat HSCs stimulated by acetaldehyde, which is likely related to its regulative effect on the cell cycle.

  1. Ambient concentrations of aldehydes in relation to Beijing Olympic air pollution control measures

    Directory of Open Access Journals (Sweden)

    J. C. Gong

    2010-08-01

    Full Text Available Aldehydes are ubiquitous constituents of the atmosphere. Their concentrations are elevated in polluted urban atmospheres. The present study was carried out to characterize three aldehydes of most health concern (formaldehyde, acetaldehyde, and acrolein in a central Beijing site in the summer and early fall of 2008 (from June to October. Measurements were made before, during, and after the Beijing Olympics to examine whether the air pollution control measures implemented to improve Beijing's air quality during the Olympics had any impact on concentrations of the three aldehydes. Average concentrations of formaldehyde, acetaldehyde and acrolein were 29.34 ± 15.12 μg/m3, 27.09 ± 15.74 μg/m3 and 2.32 ± 0.95 μg/m3, respectively, for the entire period of measurements, all being the highest among the levels measured in cities around the world in photochemical smog seasons. Among the three measured aldehydes, only acetaldehyde had a substantially reduced mean concentration during the Olympic air pollution control period compared to the pre-Olympic period. Formaldehyde and acrolein followed the changing pattern of temperature and were each significantly correlated with ozone (a secondary product of photochemical reactions. In contrast, acetaldehyde was significantly correlated with several pollutants emitted mainly from local emission sources (e.g., NO2, CO, and PM2.5. These findings suggest that local direct emissions had a larger impact on acetaldehyde than formaldehyde and acrolein.

  2. Synthesis of nanoporous carbohydrate metal-organic framework and encapsulation of selected organic compounds

    Science.gov (United States)

    Al-Ghamdi, Saleh

    Cyclodextrin metal organic frameworks (CDMOFs) with different types of cyclodextrins (CDs) (i.e., Alpha, Beta and Gamma-CD) and coordination potassium ion sources (KOH) CDMOF-a and (C7H5KO2) CDMOF-b were synthesized and fully characterized. The physical and thermal properties of the successfully produced CDMOFs were evaluated using N2 gas sorption, thermal gravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The N2 gas sorption isotherm revealed high uptake into the micropores (330 cm3.g -1 for Gamma-CDMOF-a) to macropore (125 cm3.g -1 for Gamma-CDMOF-b) structures with isotherm types I and II for Gamma-CDMOFs and Alpha-CDMOFs, respectively. The Langmuir specific surface area (SSA) of Gamma-CDMOF-a (1376 m2.g-1) was significantly higher than the SSA of Alpha-CDMOF-a (289 m2.g -1) and Beta-CDMOF-a (54 m2.g-1). The TGA of dehydrated CDMOF crystals showed the structures were thermally stable up to 300 °C. The XRD of the Gamma-CDMOFs and Alpha-CDMOFs showed a highly face-centered-cubic symmetrical structure. An Aldol condensation reaction occurred during the encapsulation of acetaldehyde, hexanal, trans-2-hexenal, and ethanol into Gamma-CDMOF-a, with a SSA of 1416 m2.g -1. However, Gamma-CDMOF-b with a SSA of 499 m2.g -1 was successfully used to encapsulate acetaldehyde. The maximum release of acetaldehyde from CDMOF-b was 53 mug of acetaldehyde per g of CDMOF, which is greater than previously reported acetaldehyde encapsulation on Beta-CD inclusion complexes.

  3. Red ginseng relieves the effects of alcohol consumption and hangover symptoms in healthy men: a randomized crossover study.

    Science.gov (United States)

    Lee, Mi-Hyang; Kwak, Jung Hyun; Jeon, Gayoung; Lee, Jong-Won; Seo, Jang-Ho; Lee, Hoon-Sang; Lee, Jong Ho

    2014-03-01

    Heavy drinking causes hangover symptoms, because the action of alcohol dehydrogenase forms acetaldehyde, which is metabolized by acetaldehyde dehydrogenase into acetate. Red ginseng shows positive effects on alcohol metabolism in animal studies. We investigated the effects of red ginseng on relieving alcohol and hangover symptoms in 25 healthy men in a randomized crossover study. At each visit (0, 1, and 2 weeks), the subjects drank 100 mL whiskey (40% alcohol) and either 100 mL water or 100 mL of a 0.321 mg mL(-1) red ginseng anti-hangover drink (RGD). We took blood samples periodically until 240 min after alcohol consumption, and we investigated the blood profiles, alcohol levels, and acetaldehyde levels. We also measured anthropometric parameters, expiratory air-alcohol levels, and hangover symptoms. The plasma alcohol concentrations within the RGD group were significantly lower than those within the placebo group after 30 min (p = 0.002), 45 min (p = 0.016), and 60 min (p = 0.009); the areas under the response curves revealed a positive effect of RGD (p = 0.051). Furthermore, the expiratory alcohol concentration was significantly lower after 30 min (p = 0.005) and 60 min (p = 0.065), and the areas under the response curves (p = 0.058) likewise revealed a positive effect of RGD. The plasma acetaldehyde level was significantly elevated at 120 min (p = 0.020), but the areas under the response curves showed a similar trend (p = 0.054). While the plasma acetaldehyde concentration slightly increased, the RGD showed positive effects on hangover symptoms. Considering the reduction of plasma alcohol levels, expiratory concentrations, and hangover severity, we conclude that red ginseng relieves the symptoms of alcohol hangover. PMID:24458173

  4. Facilitated ethanol metabolism promotes cardiomyocyte contractile dysfunction through autophagy in murine hearts

    Science.gov (United States)

    Guo, Rui; Hu, Nan; Kandadi, Machender R.; Ren, Jun

    2012-01-01

    Chronic drinking leads to myocardial contractile dysfunction where ethanol metabolism plays an essential role. Acetaldehyde, the main ethanol metabolite, mediates alcohol-induced cell injury although the underlying mechanism is still elusive. This study was designed to examine the mechanism involved in accelerated ethanol metabolism-induced cardiac defect with a focus on autophagy. Wild-type FVB and cardiac-specific overexpression of alcohol dehydrogenase mice were placed on a 4% nutrition-balanced alcohol diet for 8 weeks. Myocardial histology, immunohistochemistry, autophagy markers and signal molecules were examined. Expression of micro RNA miR-30a, a potential target of Beclin 1, was evaluated by real-time PCR. Chronic alcohol intake led to cardiac acetaldehyde accumulation, hypertrophy and overt autophagosome accumulation (LC3-II and Atg7), the effect of which was accentuated by ADH. Signaling molecules governing autophagy initiation including class III PtdIns3K, phosphorylation of mTOR and p70S6K were enhanced and dampened, respectively, following alcohol intake. These alcohol-induced signaling responses were augmented by ADH. ADH accentuated or unmasked alcohol-induced downregulation of Bcl-2, Bcl-xL and MiR-30a. Interestingly, ADH aggravated alcohol-induced p62 accumulation. Autophagy inhibition using 3-MA abolished alcohol-induced cardiomyocyte contractile anomalies. Moreover, acetaldehyde led to cardiomyocyte contractile dysfunction and autophagy induction, which was ablated by 3-MA. Ethanol or acetaldehyde increased GFP-LC3 puncta in H9c2 cells, the effect of which was ablated by 3-MA but unaffected by lysosomal inhibition using bafilomycin A1, E64D and pepstatin A. In summary, these data suggested that facilitated acetaldehyde production via ADH following alcohol intake triggered cardiac autophagosome formation along with impaired lysosomal degradation, en route to myocardial defect. PMID:22441020

  5. Evaluation of a Combined Ultraviolet Photocatalytic Oxidation(UVPCO)/Chemisorbent Air Cleaner for Indoor Air Applications

    Energy Technology Data Exchange (ETDEWEB)

    Hodgson, Alfred T.; Destaillats, Hugo; Hotchi, Toshifumi; Fisk,William J.

    2007-02-01

    We previously reported that gas-phase byproducts of incomplete oxidation were generated when a prototype ultraviolet photocatalytic oxidation (UVPCO) air cleaner was operated in the laboratory with indoor-relevant mixtures of VOCs at realistic concentrations. Under these conditions, there was net production of formaldehyde and acetaldehyde, two important indoor air toxicants. Here, we further explore the issue of byproduct generation. Using the same UVPCO air cleaner, we conducted experiments to identify common VOCs that lead to the production of formaldehyde and acetaldehyde and to quantify their production rates. We sought to reduce the production of formaldehyde and acetaldehyde to acceptable levels by employing different chemisorbent scrubbers downstream of the UVPCO device. Additionally, we made preliminary measurements to estimate the capacity and expected lifetime of the chemisorbent media. For most experiments, the system was operated at 680-780 m{sup 3}/h (400-460 cfm). A set of experiments was conducted with common VOCs introduced into the UVPCO device individually and in mixture. Compound conversion efficiencies and the production of formaldehyde and acetaldehyde were determined by comparison of compound concentrations upstream and downstream of the reactor. There was general agreement between compound conversions efficiencies determined individually and in the mixture. This suggests that competition among compounds for active sites on the photocatalyst surface will not limit the performance of the UVPCO device when the total VOC concentration is low. A possible exception was the very volatile alcohols, for which there were some indications of competitive adsorption. The results also showed that formaldehyde was produced from many commonly encountered VOCs, while acetaldehyde was generated by specific VOCs, particularly ethanol. The implication is that formaldehyde concentrations are likely to increase when an effective UVPCO air cleaner is used in

  6. Effects of whisky on plasma gastrin and cholecystokinin in young adult men.

    Science.gov (United States)

    Manabe, T; Sawai, H; Okada, Y; Funahashi, H; Yamamoto, M; Sato, M; Hayakawa, T; Yamaki, K

    2003-01-01

    Whisky (1 g/kg, 21.5% alcohol) was administered orally to healthy young adult male volunteers, and changes in the plasma concentrations of alcohol, acetaldehyde, gastrin, cholecystokinin (CCK) and serum amylase were measured over time. Values for alcohol and acetaldehyde rapidly reached a peak at 30-45 min after alcohol intake, followed by a gradual decline. The plasma gastrin concentration showed a rapid elevation, while the plasma CCK concentration did not exhibit any significant changes in the early phase after alcohol intake. Elevation of CCK was observed after 75 min, however. These results show that intake of whisky stimulates the secretion of gastrin and is associated with a later increase in CCK.

  7. Peptide bond formation through gas-phase reactions in the interstellar medium: formamide and acetamide as prototypes

    Energy Technology Data Exchange (ETDEWEB)

    Redondo, Pilar; Barrientos, Carmen; Largo, Antonio, E-mail: predondo@qf.uva.es [Computational Chemistry Group, Departamento de Química Física, Facultad de Ciencias, Universidad de Valladolid, E-47011 Valladolid (Spain)

    2014-09-20

    A theoretical study of the reactions of NH{sub 4}{sup +} with formaldehyde and CH{sub 5}{sup +} with formamide is carried out. The viability of these gas-phase ion-molecule reactions as possible sources of formamide and acetamide under the conditions of interstellar medium is evaluated. We report a theoretical estimation of the reaction enthalpies and an analysis of their potential energy surfaces. Formation of protonated formamide from the reaction between ammonium cation and formaldehyde is an exothermic process, but all the channels located on the potential energy surface leading to this product present net activation energies. For the reaction between methanium and formamide, different products are possible from a thermodynamic point of view. An analysis of its potential energy surface showed that formation of protonated acetamide and amino acetaldehyde takes place through barrier-free paths. Therefore, this reaction could be a feasible source of acetamide and amino acetaldehyde in space.

  8. Torsional symmetry dependence of S1 dynamics in molecules that under methyl internal rotation

    International Nuclear Information System (INIS)

    the single-rovibronic-level fluorescence of intermediate-case molecules that undergo methyl internal rotation is strongly influenced by the torsional symmetry of the lowest excited singlet state (S1). The most dramatic example of such symmetry dependence comes from the recent finding that the intensities of the e-e transitions in the high-resolution S1 left-arrow S0 fluorescence excitation spectra of jet-cooled acetaldehyde become very weak relative to the a-a transitions at higher beam temperatures. In this study, they rationalize this remarkable torsional symmetry dependence of electronic relaxation in acetaldehyde on the basis of internal-overall rotation coupling that leads to symmetry-selective increase in the density of states for singlet-triplet coupling. Related observations by others on aliphatic carbonyls and diazabenzenes are also discussed within the context of the coupling between the internal and overall rotation

  9. A coniferyl aldehyde dehydrogenase gene from Pseudomonas sp. strain HR199 enhances the conversion of coniferyl aldehyde by Saccharomyces cerevisiae.

    Science.gov (United States)

    Adeboye, Peter Temitope; Olsson, Lisbeth; Bettiga, Maurizio

    2016-07-01

    The conversion of coniferyl aldehyde to cinnamic acids by Saccharomyces cerevisiae under aerobic growth conditions was previously observed. Bacteria such as Pseudomonas have been shown to harbor specialized enzymes for converting coniferyl aldehyde but no comparable enzymes have been identified in S. cerevisiae. CALDH from Pseudomonas was expressed in S. cerevisiae. An acetaldehyde dehydrogenase (Ald5) was also hypothesized to be actively involved in the conversion of coniferyl aldehyde under aerobic growth conditions in S. cerevisiae. In a second S. cerevisiae strain, the acetaldehyde dehydrogenase (ALD5) was deleted. A prototrophic control strain was also engineered. The engineered S. cerevisiae strains were cultivated in the presence of 1.1mM coniferyl aldehyde under aerobic condition in bioreactors. The results confirmed that expression of CALDH increased endogenous conversion of coniferyl aldehyde in S. cerevisiae and ALD5 is actively involved with the conversion of coniferyl aldehyde in S. cerevisiae. PMID:27070284

  10. Development of hierarchically porous cobalt oxide for enhanced photo-oxidation of indoor pollutants

    International Nuclear Information System (INIS)

    Porous cobalt oxide was successfully prepared by precipitation of cobalt hydroxide followed by low temperature thermal decomposition. The morphologies of the resultant oxides remained as the corresponding hydroxides, although the morphology of cobalt hydroxides was greatly influenced by the precursor salts. The cobalt oxides with average crystal size less than 20 nm were characterized by X-ray diffraction, scanning electron microscope, BET surface area, and XPS analysis. The photocatalytic activities of the various cobalt oxides morphologies were investigated by comparing the photo-degradation of acetaldehyde under simulated solar illumination. Relative to their low order structures and reference titania samples, the hierarchical nanostructures of cobalt oxide showed excellent abilities to rapidly degrade acetaldehyde, a model air pollutant. This was attributed to the unique nature of these hierarchical cobalt oxide nanoassemblies, which contained many catalytically active reaction sites and open pores

  11. Dynamic modeling and controllability analysis of an ethanol reformer for fuel cell application

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Vanesa M.; Serra, Maria; Riera, Jordi [Institut de Robotica i Informatica Industrial (CSIC-UPC), Llorens i Artigas 4-6, 08028 Barcelona (Spain); Lopez, Eduardo [Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, ed. ETSEIB, 08028 Barcelona (Spain); Planta Piloto de Ingenieria Quimica (CONICET-UNS), Camino de la Carrindanga km7, 8000 Bahia Blanca (Argentina); Llorca, Jordi [Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, ed. ETSEIB, 08028 Barcelona (Spain)

    2010-09-15

    This work presents a controllability analysis of a low temperature ethanol reformer based on a cobalt catalyst for fuel cell application. The study is based on a non-linear dynamic model of a reformer which operates in three separate stages: ethanol dehydrogenation to acetaldehyde and hydrogen, acetaldehyde steam reforming, and water-gas-shift reaction. The controllability analysis is focused on the rapid dynamics due to mass balances and is based on a linearization of the complex non-linear model of the reformer. RGA, CN and MRI analysis tools are applied to the linear model suggesting that a good performance can be obtained with decentralized control for frequencies up to 0.1 rad s{sup -1}. (author)

  12. Study of the electrooxidation of ethanol on hydrophobic electrodes by DEMS and HPLC

    International Nuclear Information System (INIS)

    The electrochemical oxidation of ethanol in alkaline solution has been studied on Cu-PVC electrode and Ni/Cu-PVC composite electrodes modified by ruthenium nanoparticles. The techniques used were cyclic voltammetry (CV), steady-state potentiostatic method, on line differential electrochemical mass spectrometry (DEMS), and high-performance liquid chromatography (HPLC). The chemical products: acetaldehyde and acetic acid were detected measuring the proper mass charge (m/z) ratios. These products were also confirmed by HPLC. The surface modification of composite electrodes by ruthenium nanoparticles promotes the formation of acetaldehyde. As shown by DEMS, the surface modification shifts the onset potential for oxygen evolution reaction on the Cu-PVC composite electrode towards more anodic values

  13. Recent observations of organic molecules in nearby cold, dark interstellar clouds

    Science.gov (United States)

    Suzuki, H.; Ohishi, M.; Morimoto, M.; Kaifu, N.; Friberg, P.

    1985-01-01

    Recent investigations of the organic chemistry of relatively nearby cold, dark interstellar clouds are reported. Specifically, the presence of interstellar tricarbon monoxide (C3O) in Taurus Molecular Cloud 1 (TMC-1) is confirmed. The first detection in such regions of acetaldehyde (CH3CHO), the most complex oxygen-containing organic molecule yet found in dark clouds is reported, as well as the first astronomical detection of several molecular rotational transitions, including the J = 18-17 and 14-13 transitions of cyanodiacetylene (HC5N), the 1(01)-0(00) transition of acetaldehyde, and the J = 5-4 transition of C3O. A significant upper limit is set on the abundance of cyanocarbene (HCCN) as a result of the first reported interstellar search for this molecule.

  14. A theoretical study for one-dimensional modeling for VOC in a catalytic converter

    Science.gov (United States)

    Chauhan, S.; Sharma, L.; Srivastava, V. K.

    2010-07-01

    Modeling for catalytic oxidation of a volatile organic compound, acetaldehyde for the purpose of controlling tail-pipe emissions from vehicular exhaust was carried out. The model developed was one-dimensional unsteady state model, using mass and energy balance equations to predict results for acetaldehyde conversion in an adiabatic monolith operating under warm-up conditions. The equations consisted of a set of partial differential equations that are coupled and solved using Backward Implicit Scheme. Analysis of the behavior of the converter during warm up period was carried out and it was observed that the warm up was faster for a fresh catalyst and this warm up period could be reduced by introducing hot incoming exhaust gas at higher temperature.

  15. Effect of glutathione during bottle storage of sparkling wine.

    Science.gov (United States)

    Webber, Vanessa; Dutra, Sandra Valduga; Spinelli, Fernanda Rodrigues; Carnieli, Gilberto João; Cardozo, Alejandro; Vanderlinde, Regina

    2017-02-01

    Reduced glutathione (GSH) is an efficient antioxidant on limiting browning, losing varietal aromas and off-flavor formation. Therefore, this study aims to evaluate the effect of GSH addition (10, 20 and 30mgL(-1)) after the disgorging of the sparkling wine during storage. The sparkling wines were analyzed at 1, 6, 12 and 18months of storage according to the color index, concentration of the free SO2, phenolic compounds, catechin, epicatechin, caffeic acid, coumaric acid, acetaldehyde, total and reduced glutathione. The results show that GSH concentration decreased to the level of the control sparkling wine during the first 6months, and the total glutathione gradually declined up to 12months. The GSH reduces browning and acetaldehyde formation for up to 12months. However, the presence of glutathione had low or no influence on the concentration of free SO2, total phenolics, catechin, epicatechin, caffeic and coumaric acids. PMID:27596417

  16. Metabolic activities of Lactobacillus spp. strains isolated from kefir.

    Science.gov (United States)

    Yüksekdag, Zehra Nur; Beyath, Yavuz; Aslim, Belma

    2004-06-01

    A total of 21 strains of Lactobacillus species were isolated from Turkish kefir samples, in order to select the most suitable strains according to their metabolic activities including probiotic properties. As a result of the identification tests, 21 Lactobacillus isolates were identified as L. acidophilus (4%), L. helveticus (9%), L. brevis (9%), L. bulgaricus (14%), L. plantarum (14%), L. casei (19%) and L. lactis (28%). The amount of produced lactic acid, hydrogen peroxide, proteolytic activity, and acetaldehyde productions of Lactobacillus spp. were determined. Different amounts of lactic acid were produced by strains studies; however, lactic acid levels were 1.7-11.4 mg/mL. All strains produced hydrogen peroxide. L. bulgaricus Z14L strain showed no proteolytic activity, L. casei Z6L strain produced the maximum amount (0.16 mg/mL) of proteolytic activity. Acetaldehyde concentration produced in Lactobacillus strains ranged between 0.88-3.52 microg/mL.

  17. Biosynthesis of l-phenylacetyl carbinol from locally isolated yeasts

    International Nuclear Information System (INIS)

    In the present study, 250 yeast strains were isolated from samples of different natural sources as cane-molasses, decaying vegetables and bagasse using glucose enriched medium. Among these, 106 strains showed no growth in acetaldehyde (1 g/l) supplemented yeast extract-peptone dextrose plates during qualitative screening. In the course of quantitative screening, 64 acetaldehyde tolerants gave almost negligible L-PAC production (=0.5 g/l) using glucose-peptone medium in shake flasks. A comparatively better L-PAC production was observed with the rest of strains. The isolate Saccharomyces cerevisiae GCU-36 exhibited higher L-PAC production (2.58 g/l). However, lower sugar consumption and subsequent biomass formation was noted. Therefore, yeast GCU-36 was selected as a hyper producer of L-PAC in batch culture. (author)

  18. Development of hierarchically porous cobalt oxide for enhanced photo-oxidation of indoor pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, J. P., E-mail: chengjp@zju.edu.cn [Zhejiang University, State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering (China); Shereef, Anas; Gray, Kimberly A., E-mail: k-gray@northwestern.edu [Northwestern University, Center for Catalysis and Surface Science (United States); Wu, Jinsong [Northwestern University, Department of Materials Science and Engineering (United States)

    2015-03-15

    Porous cobalt oxide was successfully prepared by precipitation of cobalt hydroxide followed by low temperature thermal decomposition. The morphologies of the resultant oxides remained as the corresponding hydroxides, although the morphology of cobalt hydroxides was greatly influenced by the precursor salts. The cobalt oxides with average crystal size less than 20 nm were characterized by X-ray diffraction, scanning electron microscope, BET surface area, and XPS analysis. The photocatalytic activities of the various cobalt oxides morphologies were investigated by comparing the photo-degradation of acetaldehyde under simulated solar illumination. Relative to their low order structures and reference titania samples, the hierarchical nanostructures of cobalt oxide showed excellent abilities to rapidly degrade acetaldehyde, a model air pollutant. This was attributed to the unique nature of these hierarchical cobalt oxide nanoassemblies, which contained many catalytically active reaction sites and open pores.

  19. Infrared Absorption Spectroscopy and Chemical Kinetics of Free Radicals, Final Technical Report

    Science.gov (United States)

    Curl, Robert F.; Glass, Graham P.

    2004-11-01

    This research was directed at the detection, monitoring, and study of the chemical kinetic behavior by infrared absorption spectroscopy of small free radical species thought to be important intermediates in combustion. Work on the reaction of OH with acetaldehyde has been completed and published and work on the reaction of O({sup 1}D) with CH{sub 4} has been completed and submitted for publication. In the course of our investigation of branching ratios of the reactions of O({sup 1}D) with acetaldehyde and methane, we discovered that hot atom chemistry effects are not negligible at the gas pressures (13 Torr) initially used. Branching ratios of the reaction of O({sup 1}D) with CH{sub 4} have been measured at a tenfold higher He flow and fivefold higher pressure.

  20. Prebiotic synthesis of histidine

    Science.gov (United States)

    Shen, C.; Yang, L.; Miller, S. L.; Oro, J.

    1990-01-01

    The prebiotic formation of histidine (His) has been accomplished experimentally by the reaction of erythrose with formamidine followed by a Strecker synthesis. In the first step of this reaction sequence, the formation of imidazole-4-acetaldehyde took place by the condensation of erythrose and formamidine, two compounds that are known to be formed under prebiotic conditions. In a second step, the imidazole-4-acetaldehyde was converted to His, without isolation of the reaction products by adding HCN and ammonia to the reaction mixture. LC, HPLC, thermospray liquid chromatography-mass spectrometry, and tandem mass spectrometry were used to identify the product, which was obtained in a yield of 3.5% based on the ratio of His/erythrose. This is a new chemical synthesis of one of the basic amino acids which had not been synthesized prebiotically until now.

  1. The Role of CYP2E1 in Alcohol Metabolism and Sensitivity in the Central Nervous System

    Science.gov (United States)

    Heit, Claire; Dong, Hongbin; Chen, Ying; Thompson, David C.; Deitrich, Richard A.; Vasiliou, Vasilis

    2015-01-01

    Ethanol consumption has effects on the central nervous system (CNS), manifesting as motor incoordination, sleep induction (hypnosis), anxiety, amnesia, and the reinforcement or aversion of alcohol consumption. Acetaldehyde (the direct metabolite of ethanol oxidation) contributes to many aspects of the behavioral effects of ethanol. Given acetaldehyde cannot pass through the blood brain barrier, its concentration in the CNS is primarily determined by local production from ethanol. Catalase and cytochrome P450 2E1(CYP2E1) represent the major enzymes in the CNS that catalyze ethanol oxidation. CYP2E1 is expressed abundantly within the microsomes of certain brain cells and is localized to particular brain regions. This chapter focuses on the discussion of CYP2E1 in ethanol metabolism in the CNS, covering topics including how it is regulated, where it is expressed and how it influences sensitivity to ethanol in the brain. PMID:23400924

  2. Declinol, a Complex Containing Kudzu, Bitter Herbs (Gentian, Tangerine Peel) and Bupleurum, Significantly Reduced Alcohol Use Disorders Identification Test (AUDIT) Scores in Moderate to Heavy Drinkers: A Pilot Study

    OpenAIRE

    Kushner, Steven; HAN, DAVID; Oscar-Berman, Marlene; B. William Downs; Margaret A. Madigan; Giordano, John; Beley, Thomas; Jones, Scott; Barh, Debmayla; Simpatico, Thomas; Dushaj, Kristina; Lohmann, Raquel; Braverman, Eric R; Schoenthaler, Stephen; Ellison, David

    2013-01-01

    It is well established that inherited human aldehyde dehydrogenase 2 (ALDH-2) deficiency reduces the risk for alcoholism. Kudzu plants and extracts have been used for 1,000 years in traditional Chinese medicine to treat alcoholism. Kudzu contains daidzin, which inhibits ALDH-2 and suppresses heavy drinking in rodents. Decreased drinking due to ALDH-2 inhibition is attributed to aversive properties of acetaldehyde accumulated during alcohol consumption. However not all of the anti-alcohol prop...

  3. Ethanolamine utilization in Vibrio alginolyticus

    OpenAIRE

    Khatri Neelam; Khatri Indu; Subramanian Srikrishna; Raychaudhuri Saumya

    2012-01-01

    Abstract Ethanolamine is used as an energy source by phylogenetically diverse bacteria including pathogens, by the concerted action of proteins from the eut-operon. Previous studies have revealed the presence of eutBC genes encoding ethanolamine-ammonia lyase, a key enzyme that breaks ethanolamine into acetaldehyde and ammonia, in about 100 bacterial genomes including members of gamma-proteobacteria. However, ethanolamine utilization has not been reported for any member of the Vibrio genus. O...

  4. Comparative Genomics of Ethanolamine Utilization▿ † ‡

    OpenAIRE

    Tsoy, Olga; Ravcheev, Dmitry; Mushegian, Arcady

    2009-01-01

    Ethanolamine can be used as a source of carbon and nitrogen by phylogenetically diverse bacteria. Ethanolamine-ammonia lyase, the enzyme that breaks ethanolamine into acetaldehyde and ammonia, is encoded by the gene tandem eutBC. Despite extensive studies of ethanolamine utilization in Salmonella enterica serovar Typhimurium, much remains to be learned about EutBC structure and catalytic mechanism, about the evolutionary origin of ethanolamine utilization, and about regulatory links between t...

  5. Comparative genomics of ethanolamine utilization

    OpenAIRE

    Tsoy, Olga; Ravcheev, Dmitry; Mushegian, Arcady

    2009-01-01

    Ethanolamine can be used as a source of carbon and nitrogen by phylogenetically diverse bacteria. Ethanolamine-ammonia lyase, the enzyme that breaks ethanolamine into acetaldehyde and ammonia, is encoded by the gene tandem eutBC. Despite extensive studies of ethanolamine utilization in Salmonella enterica serovar Typhimurium, much remains to be learned about EutBC structure and catalytic mechanism, about the evolutionary origin of ethanolamine utilization, and about regulatory links between t...

  6. Effects of Hypobaric Storage on Physiological and Biochemical Changes in Postharvest Dong Jujube Fruit During Cold Storage

    Institute of Scientific and Technical Information of China (English)

    XUE Meng-lin; ZHANG Ping; ZHANG Ji-shu; WANG Li

    2003-01-01

    Effects of hypobaric storage on physiological and biochemical changes in Dong jujube fruit wereinvestigated. Hypobaric storage significantly delayed the decrease in firmness and maintained content of ascor-bic acid, reduced accumulation of ethanol and acetaldehyde in pulp and respiration, inhibited activities of as-corbic acid oxidase and alcohol dehydrogenase and slowed down the rate of ethylene production, but had littleeffect on flesh browning of the fruit.

  7. Photolysis of oxygen saturated ethers in the presence of Sn (Ⅱ) or Cu (Ⅱ) salts

    Institute of Scientific and Technical Information of China (English)

    施敏

    2000-01-01

    Photolysis of diethyl ether-oxygen charge transfer complex the presence of Sn(Ⅱ) or Cu(Ⅱ) salts gave higher yields of the oxiation products, ethyl acetate, acetaldehyde, ethanol,ethyl formate and methanol compared with those without the salts. In addition, the photolysis of an oxygen saturated tetrahydrofuran (THF) or dibutyl lether solution gave γ-butyro-Their yields were also affected by the addition of Cu(Ⅱ) or Sn(Ⅱ) salts.

  8. Alcohol-Induced Alterations in Hepatic Microtubule Dynamics Can Be Explained by Impaired Histone Deacetylase 6 Function

    OpenAIRE

    Shepard, Blythe D.; Joseph, Rohan A.; Kannarkat, George T.; Rutledge, Tara M.; Dean J. Tuma; Tuma, Pamela L.

    2008-01-01

    We have been using polarized, hepatic WIF-B cells to examine ethanol-induced liver injury. These cells polarize in culture and maintain numerous liver-specific activities including the ability to metabolize alcohol. Previously, we found that microtubules were more highly acetylated and more stable in ethanol-treated WIF-B cells and that increased microtubule acetylation required ethanol metabolism and was likely mediated by acetaldehyde. This study was aimed at identifying the mechanism respo...

  9. Deactivation Studies of Rh/Ce0.8Zr0.2O2 Catalysts in Low Temperature Ethanol Steam Reforming

    Energy Technology Data Exchange (ETDEWEB)

    Platon, Alex; Roh, Hyun-Seog; King, David L.; Wang, Yong

    2007-10-30

    Rapid deactivation of Rh/Ce0.8Zr0.2O2 catalysts in low temperature ethanol steam reforming was studied. A significant build-up of carbonaceous intermediate, instead of carbon deposit, was observed at a lower reaction temperature which was attributed to the rapid catalyst deactivation. Co-feed experiments indicated that acetone and ethylene caused more severe catalyst deactivation than other oxygenates such as acidic acid and acetaldehyde.

  10. Nucleic acid molecules conferring enhanced ethanol tolerance and microorganisms having enhanced tolerance to ethanol

    Science.gov (United States)

    Brown, Steven; Guss, Adam; Yang, Shihui; Karpinets, Tatiana; Lynd, Lee; Shao, Xiongjun

    2014-01-14

    The present invention provides isolated nucleic acid molecules which encode a mutant acetaldehyde-CoA/alcohol dehydrogenase or mutant alcohol dehydrogenase and confer enhanced tolerance to ethanol. The invention also provides related expression vectors, genetically engineered microorganisms having enhanced tolerance to ethanol, as well as methods of making and using such genetically modified microorganisms for production of biofuels based on fermentation of biomass materials.

  11. Research advances in the catalysts for the selective oxidation of ethane to aldehydes

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhe; ZHAO Zhen; XU Chunming

    2005-01-01

    Selective oxidation of ethane to aldehydes is one of the most difficult processes in the catalysis researches of low alkanes. The development of selective oxidation of ethane to aldehydes (formaldehyde, acetaldehyde and acrolein) is discussed. The latest progress of the catalysts, including bulk or supported metal oxide catalysts, highly dispersed and isolated active sites catalysts, and the photo-catalytic ethane oxidation catalysts, partial oxidation of ethane in the gas phase, and the proposed reaction pathways from ethane to aldehydes are involved.

  12. Real-world driving speciated VOC hot start missions of the 2001 French passenger car fleet

    OpenAIRE

    FLANDRIN, Y; Vidon, R; Cazier, F.; Hue, S.; DECHAUX, JC; Nollet, V.

    2001-01-01

    A 25 passenger cars sample was selected on the basis of a 2001 year French fleet prediction. Various types of vehicle technologies, i.e. diesel and petrol cars both equipped with or without catalyst, were tested on a chassis dynamometer with constant volume sampling for regulated emissions and individual Volatile Organic Compounds determination. A particular emphasis has been placed on toxic and/or photochemically reactive compounds such as benzene, formaldehyde, acetaldehyde and 1,3-b...

  13. Evaluation of Volatile Organic Compounds and Carbonyl Compounds Present in the Cabins of Newly Produced, Medium- and Large-Size Coaches in China

    OpenAIRE

    Yan-Yang Lu; Yi Lin; Han Zhang; Dongxiao Ding; Xia Sun; Qiansheng Huang; Lifeng Lin; Ya-Jie Chen; Yu-Lang Chi; Sijun Dong

    2016-01-01

    An air-conditioned coach is an important form of transportation in modern motorized society; as a result, there is an increasing concern of in-vehicle air pollution. In this study, we aimed to identify and quantify the levels of volatile organic compounds (VOCs) and carbonyl compounds (CCs) in air samples collected from the cabins of newly produced, medium- and large-size coaches. Among the identified VOCs and CCs, toluene, ethylbenzene, xylene, formaldehyde, acetaldehyde, acrolein/acetone, a...

  14. Emissions of aldehydes and ketones from a two-stroke engine using ethanol and ethanol-blended gasoline as fuel.

    Science.gov (United States)

    Magnusson, Roger; Nilsson, Calle; Andersson, Barbro

    2002-04-15

    Besides aliphatic gasoline, ethanol-blended gasoline intended for use in small utility engines was recently introduced on the Swedish market. For small utility engines, little data is available showing the effects of these fuels on exhaust emissions, especially concerning aldehydes and ketones (carbonyls). The objective of the present investigation was to study carbonyl emissions and regulated emissions from a two-stroke chain saw engine using ethanol, gasoline, and ethanol-blended gasoline as fuel (0%, 15%, 50%, 85%, and 100% ethanol). The effects of the ethanol-blending level and mechanical changes of the relative air/fuel ratio, lambda, on exhaust emissions was investigated, both for aliphatic and regular gasoline. Formaldehyde, acetaldehyde, and aromatic aldehydes were the most abundant carbonyls in the exhaust. Acetaldehyde dominated for all ethanol-blended fuels (1.2-12 g/kWh, depending on the fuel and lambda), and formaldehyde dominated for gasoline (0.74-2.3 g/kWh, depending on the type of gasoline and lambda). The main effects of ethanol blending were increased acetaldehyde emissions (30-44 times for pure ethanol), reduced emissions of all other carbonyls exceptformaldehyde and acrolein (which showed a more complex relation to the ethanol content), reduced carbon monoxide (CO) and ntirogen oxide (NO) emissions, and increased hydrocarbon (HC) and nitrogen dixodie (NO2) emissions. The main effects of increasing lambda were increased emissions of carbonyls and nitrogen oxides (NOx) and reduced CO and HC emissions. When the two types of gasoline are considered, benzaldehyde and tolualdehyde could be directly related to the gasoline content of aromatics or olefins, but also acrolein, propanal, crotonaldehyde, and methyl ethyl ketone mainly originated from aromatics or olefins, while the main source for formaldehyde, acetaldehyde, acetone, methacrolein, and butanal was saturated aliphatic hydrocarbons.

  15. Radical cation salts induced domino reaction of anilines with enol ethers: Synthesis of 1,2,3,4-tetrahydroquinoline derivatives

    Institute of Scientific and Technical Information of China (English)

    Xiao Dong Jia; Yan Ren; Cong Dde Huo; Wen Juan Wang; Xiang Ning Chen; Qiong Fu; Xi Cun Wang

    2011-01-01

    A domino reaction of anilines with cyclic and acyclic enol ethers induced by catalytic amounts of TBPA+ (5 mol%) was investigated and a series of 2,4-disubstituted-1,2,3,4-tetrahydroquinolines were synthesized. Different from cyclic enol ethers, when acyclic enol ethers were used in the reaction, they serve as surrogates of acetaldehyde, producing a series of 2-methyl-4-anilino-1,2,3,4-tetrahydroquinolines. A single electron transfer mechanism was proposed to rationalize the products formation.

  16. Teores de compostos orgânicos em cachaças produzidas na região norte fluminense - Rio de Janeiro Organic compounds contents in cachaças produced in the northern Rio de Janeiro State - RJ

    OpenAIRE

    Leandro Marelli de Souza; Karla Silva Ferreira; Luís César Passoni; Alice Barreto Bevitori; Karen Vieira Melo; Arivaldo Ribeiro Viana

    2009-01-01

    This work aimed to quantify some organic compounds in "cachaças" (sugar cane spirit). The ethyl alcohol was quantified by densimetry, after distillation. The acetic acid, methyl alcohol, n-propyl alcohol, n-butyl alcohol, isobutyl alcohol, isoamyl alcohol (mixture of 2-methyl-butyl and 3-methyl-butyl), ethyl acetate and acetaldehyde were determined by gas chromatography; and the furfural, 5-hydroxy-methylfurfural and acrolein by high efficiency liquid chromatography. From the 30 samples analy...

  17. Silica-Titania Composite (STC)'s Performance in the Photocatalytic Oxidation of Polar VOCs

    Science.gov (United States)

    Levine, Lanfang H.; Coutts, Janelle; Richards, Jeffrey; Mazyck, David; Mazyck, David

    2011-01-01

    The objective of this paper is to determine the performance of a Silica-Titania Composite (STC) in the photocatalytic oxidation (PCO) of polar VOCs for potential applications in trace contaminant control within space habitats such as the ISS and CEV Orion. Tests were carried out in a bench scale STC-packed annular reactor under continuous illumination by either a UV-C germicidal lamp(lambda (sub max) = 254 nm) or UV-A fluorescent BLB (lambda(sub max) = 365 nm) for the removal of ethanol (a predominant polar VOC in the ISS cabin). The STC's performance was evaluated in terms of the ethanol mineralization rate, mineralization efficiency, and the extent of its oxidation intermediate (acetaldehyde) formation in response to the type of light source (photon energy and photon flux) and relative humidity (RH) implemented. Results demonstrated that acetaldehyde was the only quantifiable intermediate in the effluent under UV illumination, but was not found in the dark adsorption experiments. The mineralization rate increased with an increase in photon energy (UV-C greater than UV-A), even though both lamps were adjusted to emit the same incident photon flux, and also increased with increasing photon flux. However, photonic efficiency decreased as the photon flux increased. More importantly, a higher photon flux gave rise to a lower effluent acetaldehyde concentration. The effect of RH on PCO was complex and intriguing because it affected both physical adsorption and photocatalytic oxidation. In general, increasing RH caused a decrease in adsorption capacity for ethanol and reduced the mineralization efficiency with a concomitant higher acetaldehyde evolution rate. The effect of RH was less profound than that of photon flux.

  18. Rapid Monitoring of Mercury in Air from an Organic Chemical Factory in China Using a Portable Mercury Analyzer

    OpenAIRE

    Akira Yasutake; Jin Ping Cheng; Masako Kiyono; Shimpei Uraguchi; Xiaojie Liu; Kyoko Miura; Yoshiaki Yasuda; Nikolay Mashyanov

    2011-01-01

    A chemical factory, using a production technology of acetaldehyde with mercury catalysis, was located southeast of Qingzhen City in Guizhou Province, China. Previous research showed heavy mercury pollution through an extensive downstream area. A current investigation of the mercury distribution in ambient air, soils, and plants suggests that mobile mercury species in soils created elevated mercury concentrations in ambient air and vegetation. Mercury concentrations of up to 600 ng/m3 in air o...

  19. Analysis of alcohol dehydrogenase inhibitors from Desmodium styracifolium using centrifugal ultrafiltration coupled with HPLC-MS

    OpenAIRE

    Liu Liangliang; Chen Miao; Chen Xiaoqing

    2015-01-01

    Alcohol dehydrogenase (ADH) inhibitors play an important role in the treatment of human methanol or ethylene glycol poisoning and the suppression of acetaldehyde accumulation in alcoholics. In this study, centrifugal ultrafiltration coupled with high performance liquid chromatography-mass spectrometry (HPLC-MS) was utilized to screen and identify ADH inhibitors from ethyl acetate extract of Desmosium styracifolium (Osb.) Merr. The experiment conditions of c...

  20. Carbonyl compound emissions from a heavy-duty diesel engine fueled with diesel fuel and ethanol-diesel blend.

    Science.gov (United States)

    Song, Chonglin; Zhao, Zhuang; Lv, Gang; Song, Jinou; Liu, Lidong; Zhao, Ruifen

    2010-05-01

    This paper presents an investigation of the carbonyl emissions from a direct injection heavy-duty diesel engine fueled with pure diesel fuel (DF) and blended fuel containing 15% by volume of ethanol (E/DF). The tests have been conducted under steady-state operating conditions at 1200, 1800, 2600 rpm and idle speed. The experimental results show that acetaldehyde is the most predominant carbonyl, followed by formaldehyde, acrolein, acetone, propionaldehyde and crotonaldehyde, produced from both fuels. The emission factors of total carbonyls vary in the range 13.8-295.9 mg(kWh)(-1) for DF and 17.8-380.2mg(kWh)(-1) for E/DF, respectively. The introduction of ethanol into diesel fuel results in a decrease in acrolein emissions, while the other carbonyls show general increases: at low engine speed (1200 rpm), 0-55% for formaldehyde, 4-44% for acetaldehyde, 38-224% for acetone, and 5-52% for crotonaldehyde; at medium engine speed (1800 rpm), 106-413% for formaldehyde, 4-143% for acetaldehyde, 74-113% for acetone, 114-1216% for propionaldehyde, and 15-163% for crotonaldehyde; at high engine speed (2600 rpm), 36-431% for formaldehyde, 18-61% for acetaldehyde, 22-241% for acetone, and 6-61% for propionaldehyde. A gradual reduction in the brake specific emissions of each carbonyl compound from both fuels is observed with increase in engine load. Among three levels of engine speed employed, both DF and E/DF emit most CBC emissions at high engine speed. On the whole, the presence of ethanol in diesel fuel leads to an increase in aldehyde emissions.

  1. Disulfiram Attenuates Drug-Primed Reinstatement of Cocaine Seeking via Inhibition of Dopamine β-Hydroxylase

    OpenAIRE

    Schroeder, Jason P; Cooper, Debra A.; Schank, Jesse R.; Lyle, Megan A.; Gaval-Cruz, Meriem; Ogbonmwan, Yvonne E.; Pozdeyev, Nikita; Freeman, Kimberly G; Iuvone, P. Michael; Edwards, Gaylen L.; Holmes, Philip V.; Weinshenker, David

    2010-01-01

    The antialcoholism medication disulfiram (Antabuse) inhibits aldehyde dehydrogenase (ALDH), which results in the accumulation of acetaldehyde upon ethanol ingestion and produces the aversive ‘Antabuse reaction' that deters alcohol consumption. Disulfiram has also been shown to deter cocaine use, even in the absence of an interaction with alcohol, indicating the existence of an ALDH-independent therapeutic mechanism. We hypothesized that disulfiram's inhibition of dopamine β-hydroxylase (DBH),...

  2. First-pass gastric mucosal metabolism of ethanol is negligible in the rat.

    OpenAIRE

    SMITH, T; DeMaster, E G; Furne, J K; Springfield, J; Levitt, M D

    1992-01-01

    Ethanol metabolism by gastric alcohol dehydrogenase (ADH) is thought to be an important determinant of peripheral ethanol time-concentration curves (AUCs) in rats and humans. We quantitated this metabolism in rats by measuring the gastric absorption of oral ethanol (0.25 g/kg) and the gastric venous-arterial (V-A) difference of ethanol versus ethanol metabolites (acetate, acetaldehyde, and bicarbonate). Over 1 h, approximately 20% of the ethanol was absorbed from the stomach and 70% was empti...

  3. Eletroxidação do etanol em eletrodos de Ti/IrO2 Electro-oxidation of ethanol in Ti/IrO2

    OpenAIRE

    CARLOS H. V. FIDELIS; Paulo M. Donate; Adalgisa R. de Andrade

    2001-01-01

    It has been carried out an investigation of ethanol electro-oxidation on Ti/IrO2 electrodes. The experimental results show a high selectivity towards acetaldehyde formation thus, offering potential advantages in cost and availability of raw material. It has been observed that the electrode is partially blocked by a film formed after the oxidation of the starting material which can be removed by pulse technique between RDO and RDH onset. The mechanism and the selectivity of the product formed ...

  4. Eletroxidação do etanol em eletrodos de Ti/IrO2

    OpenAIRE

    Fidelis Carlos H.V.; Donate Paulo M.; Andrade Adalgisa R. de

    2001-01-01

    It has been carried out an investigation of ethanol electro-oxidation on Ti/IrO2 electrodes. The experimental results show a high selectivity towards acetaldehyde formation thus, offering potential advantages in cost and availability of raw material. It has been observed that the electrode is partially blocked by a film formed after the oxidation of the starting material which can be removed by pulse technique between RDO and RDH onset. The mechanism and the selectivity of the product formed ...

  5. Aldehydes in relation to air pollution sources: A case study around the Beijing Olympics

    Science.gov (United States)

    Altemose, Brent; Gong, Jicheng; Zhu, Tong; Hu, Min; Zhang, Liwen; Cheng, Hong; Zhang, Lin; Tong, Jian; Kipen, Howard M.; Ohman-Strickland, Pamela; Meng, Qingyu; Robson, Mark G.; Zhang, Junfeng

    2015-05-01

    This study was carried out to characterize three aldehydes of health concern (formaldehyde, acetaldehyde, and acrolein) at a central Beijing site in the summer and early fall of 2008 (from June to October). Aldehydes in polluted atmospheres come from both primary and secondary sources, which limits the control strategies for these reactive compounds. Measurements were made before, during, and after the Beijing Olympics to examine whether the dramatic air pollution control measures implemented during the Olympics had an impact on concentrations of the three aldehydes and their underlying primary and secondary sources. Average concentrations of formaldehyde, acetaldehyde and acrolein were 29.3 ± 15.1 μg/m3, 27.1 ± 15.7 μg/m3 and 2.3 ± 1.0 μg/m3, respectively, for the entire period of measurements, all being at the high end of concentration ranges measured in cities around the world in photochemical smog seasons. Formaldehyde and acrolein increased during the pollution control period compared to the pre-Olympic Games, followed the changing pattern of temperature, and were significantly correlated with ozone and with a secondary formation factor identified by principal component analysis (PCA). In contrast, acetaldehyde had a reduction in mean concentration during the Olympic air pollution control period compared to the pre-Olympic period and was significantly correlated with several pollutants emitted from local emission sources (e.g., NO2, CO, and PM2.5). Acetaldehyde was also more strongly associated with primary emission sources including vegetative burning and oil combustion factors identified through the PCA. All three aldehydes were lower during the post-Olympic sampling period compared to the before and during Olympic periods, likely due to seasonal and regional effects. Our findings point to the complexity of source control strategies for secondary pollutants.

  6. Cloning and characterization of a locus encoding an indolepyruvate decarboxylase involved in indole-3-acetic acid synthesis in Erwinia herbicola.

    OpenAIRE

    Brandl, M. T.; Lindow, S E

    1996-01-01

    Erwinia herbicola 299R synthesizes indole-3-acetic acid (IAA) primarily by the indole-3-pyruvic acid pathway. A gene involved in the biosynthesis of IAA was cloned from strain 299R. This gene (ipdC) conferred the synthesis of indole-3-acetaldehyde and tryptophol upon Escherichia coli DH5 alpha in cultures supplemented with L-tryptophan. The deduced amino acid sequence of the gene product has high similarity to that of the indolepyruvate decarboxylase of Enterobacter cloacae. Regions within py...

  7. Nutraceutical strategies for ameliorating the toxic effects of alcohol.

    Science.gov (United States)

    McCarty, Mark F

    2013-04-01

    Rodent studies reveal that oxidative stress, much of it generated via induction/activation of NADPH oxidase, is a key mediator of a number of the pathogenic effects of chronic ethanol overconsumption. The highly reactive ethanol metabolite acetaldehyde is a key driver of this oxidative stress, and doubtless works in other ways to promote alcohol-induced pathology. Effective antioxidant measure may therefore be useful for mitigating the adverse health consequences of alcohol consumption; spirulina may have particular utility in this regard, as its chief phycochemical phycocyanobilin has recently been shown to function as an inhibitor of certain NADPH oxidase complexes, mimicking the physiological role of its chemical relatives biliverdin/bilirubin in this respect. Moreover, certain nutraceuticals, including taurine, pantethine, and lipoic acid, may have the potential to boost the activity of the mitochondrial isoform of aldehyde dehydrogenase, ALDH-2, accelerating conversion of acetaldehyde to acetate (which arguably has protective health effects). Little noticed clinical studies conducted nearly three decades ago reported that pre-ingestion of either taurine or pantethine could blunt the rise in blood acetaldehyde following ethanol consumption. Other evidence suggests that lipoic acid may function within mitochondria to maintain aldehyde dehydrogenase in a reduced active conformation; the impact of this agent on ethanol metabolism has however received little or no study. Studies evaluating the impact of nutracetical strategies on prevention of hangovers - which likely are mediated by acetaldehyde - may represent a quick, low-cost way to identify nutraceutical regimens that merit further attention for their potential impact on alcohol-induced pathology. Measures which boost or preserve ALDH-2 activity may also have important antioxidant potential, as this enzyme functions physiologically to protect cells from toxic aldehydes generated by oxidant stress. PMID

  8. Induction of brain cytochrome P450 2E1 boosts the locomotor-stimulating effects of ethanol in mice.

    Science.gov (United States)

    Ledesma, Juan Carlos; Miquel, Marta; Pascual, María; Guerri, Consuelo; Aragon, Carlos M G

    2014-10-01

    In the central nervous system ethanol (EtOH) is metabolized into acetaldehyde by different enzymes. Brain catalase accounts for 60% of the total production of EtOH-derived acetaldehyde, whereas cerebral cytochrome P450 2E1 (CYP 2E1) produces 20% of this metabolite. Acetaldehyde formed by the activity of central catalase has been implicated in some of the neurobehavioral properties of EtOH, yet the contribution of CYP 2E1 to the pharmacological actions of this drug has not been investigated. Here we assessed the possible participation of CYP 2E1 in the behavioral effects of EtOH. Thus, we induced CYP 2E1 activity and expression by exposing mice to chronic acetone intake (1% v/v for 10 days) and examined its consequences on the stimulating and uncoordinating effects of EtOH (0-3.2 g/kg) injected intraperitoneally. Our data showed that 24 h after withdrawal of acetone brain expression and activity of CYP 2E1 was induced. Furthermore, the locomotion produced by EtOH was boosted over the same interval of time. Locomotor stimulation produced by amphetamine or tert-butanol was unchanged by previous treatment with acetone. EtOH-induced motor impairment as evaluated in a Rota-Rod apparatus was unaffected by the preceding exposure to acetone. These results indicate that cerebral CYP 2E1 activity could contribute to the locomotor-stimulating effects of EtOH, and therefore we suggest that centrally produced acetaldehyde might be a possible mediator of some EtOH-induced pharmacological effects.

  9. Acetate Causes Alcohol Hangover Headache in Rats

    OpenAIRE

    Maxwell, Christina R.; Rebecca Jay Spangenberg; Hoek, Jan B.; Silberstein, Stephen D.; Oshinsky, Michael L.

    2010-01-01

    BACKGROUND: The mechanism of veisalgia cephalgia or hangover headache is unknown. Despite a lack of mechanistic studies, there are a number of theories positing congeners, dehydration, or the ethanol metabolite acetaldehyde as causes of hangover headache. METHODS: We used a chronic headache model to examine how pure ethanol produces increased sensitivity for nociceptive behaviors in normally hydrated rats. RESULTS: Ethanol initially decreased sensitivity to mechanical stimuli on the face (ana...

  10. Natural Products for the Prevention and Treatment of Hangover and Alcohol Use Disorder

    OpenAIRE

    Fang Wang; Ya Li; Yu-Jie Zhang; Yue Zhou; Sha Li; Hua-Bin Li

    2016-01-01

    Alcoholic beverages such as beer, wine and spirits are widely consumed around the world. However, alcohol and its metabolite acetaldehyde are toxic and harmful to human beings. Chronic alcohol use disorder or occasional binge drinking can cause a wide range of health problems, such as hangover, liver damage and cancer. Some natural products such as traditional herbs, fruits, and vegetables might be potential dietary supplements or medicinal products for the prevention and treatment of the pro...

  11. Assessment of Pollutant Spread from a Building Basement with three Ventilation Systems

    OpenAIRE

    Koffi, Juslin

    2009-01-01

    International audience Ventilation aims at providing a sufficient air renewal for ensuring a good indoor air quality (IAQ), yet building energy policies are leading to adapting various ventilation strategies minimising energy losses through air renewal. A recent IAQ evaluation campaign in French dwellings shows important pollution of living spaces by VOCs such as formaldehyde, acetaldehyde or hexanal, particularly in buildings equipped with a garage. Besides, radon emission from soil is a ...

  12. Characterization of volatile compounds of “Drenja”, an alcoholic beverage obtained from the fruits of cornelian cherry

    OpenAIRE

    VELE TEŠEVIĆ; NINOSLAV NIKIĆEVIĆ; SLOBODAN MILOSAVLJEVIĆ; DANICA BAJIĆ; VLATKA VAJS; IVAN VUČKOVIĆ; LJUBODRAG VUJISIĆ; IRIS ĐORĐEVIĆ; MIROSLAVA STANKOVIĆ; MILOVAN VELIČKOVIĆ

    2009-01-01

    In this study, volatile compounds were analyzed in five samples of home-made spirit beverage made by the distillation of fermented fruits of cornelian cherry (Cornus mas L.). The major volatile compounds, besides ethanol, identified and quantified were: methanol, acetaldehyde, 1-propanol, ethyl acetate, 2-methyl-1-propanol, 1-butanol, amyl alcohols, 1-hexanol and 2-phenylethanol. The minor volatiles were submitted to liquid–liquid extraction with dichloromethane and analyzed by gas chromatogr...

  13. Mechanisms involved in the induction of aneuploidy: the significance of chromosome loss

    OpenAIRE

    A.I. Seoane; Güerci, A.M; F.N. Dulout

    2000-01-01

    The induction of aneuploidy by physical and chemical agents using different test systems was evaluated. The effect of X-rays, caffeine, acetaldehyde, ethanol, diethylstilbestrol, propionaldehyde, and chloral hydrate was studied by chromosome counting in Chinese hamster embryonic diploid cells. Aneugenic ability of cadmium chloride, cadmium sulfate, potassium dichromate, chromium chloride, nickel chloride, and nickel sulfate was assessed by means of anaphase-telophase analysis in Chinese hamst...

  14. Emissions of volatile organic compounds from Quercus ilex L. measured by Proton Transfer Reaction Mass Spectrometry under different environmental conditions

    Science.gov (United States)

    Holzinger, R.; Sandoval-Soto, L.; Rottenberger, S.; Crutzen, P. J.; Kesselmeier, J.

    2000-08-01

    Volatile organic compound (VOC) emissions of the Mediterranean holm oak (Quercus ilex L.) were investigated using a fast Proton Transfer Reaction Mass Spectrometry (PTR-MS) instrument for analysis. This technique is able to measure compounds with a proton affinity higher than water with a high time resolution of 1 s per compound. Hence nearly all VOCs can be detected on-line. We could clearly identify the emission of methanol, acetaldehyde, ethanol, acetone, acetic acid, isoprene, monoterpenes, toluene, and C10-benzenes. Some other species could be tentatively denominated. Among these are the masses 67 (cyclo pentadiene), mass 71 (tentatively attributed to methyl vinyl ketone (MVK) and metacrolein (MACR)), 73 (attributed to methyl ethyl ketone (MEK)), 85 (C6H12 or hexanol), and 95 (vinylfuran or phenol). The emissions of all these compounds (identified as well as nonidentified) together represent 99% of all masses detected and account for a carbon loss of 0.7-2.9% of the net photosynthesis. Of special interest was a change in the emission behavior under changing environmental conditions such as flooding or fast light/dark changes. Flooding of the root system caused an increase of several VOCs between 60 and 2000%, dominated by the emission of ethanol and acetaldehyde, which can be explained by the well described production of ethanol under anoxic conditions of the root system and the recently described subsequent transport and partial oxidation to acetaldehyde within the green leaves. However, ethanol emissions were dominant. Additionally, bursts of acetaldehyde with lower ethanol emission were also found under fast light/dark changes. These bursts are not understood.

  15. Alcohol intake and ovarian cancer risk : A pooled analysis of 10 cohort studies

    OpenAIRE

    Genkinger, J.M.; Hunter, D. J.; Spiegelman, D; Anderson, K. E.; Buring, J. E.; Freudenheim, J. L.; Goldbohm, R. A.; Harnack, L.; Hankinson, S E; Larsson, S C; Leitzmann, M; McCullough, M.L.; Marshall, J.; Miller, A.B.; Rodriguez, C.

    2006-01-01

    Alcohol has been hypothesized to promote ovarian carcinogenesis by its potential to increase circulating levels of estrogen and other hormones; through its oxidation byproduct, acetaldehyde, which may act as a cocarcinogen; and by depletion of folate and other nutrients. Case-control and cohort studies have reported conflicting results relating alcohol intake to ovarian cancer risk. We conducted a pooled analysis of the primary data from ten prospective cohort studies. The analysis included 5...

  16. TiO2 Nanotubes with Open Channels as Deactivation-Resistant Photocatalyst for the Degradation of Volatile Organic Compounds.

    Science.gov (United States)

    Weon, Seunghyun; Choi, Wonyong

    2016-03-01

    We synthesized ordered TiO2 nanotubes (TNT) and compared their photocatalytic activity with that of TiO2 nanoparticles (TNP) film during the repeated cycles of photocatalytic degradation of gaseous toluene and acetaldehyde to test the durability of TNT as an air-purifying photocatalyst. The photocatalytic activity of TNT showed only moderate reduction after the five cycles of toluene degradation, whereas TNP underwent rapid deactivation as the photocatalysis cycles were repeated. Dynamic SIMS analysis showed that carbonaceous deposits were formed on the surface of TNP during the photocatalytic degradation of toluene, which implies that the photocatalyst deactivation should be ascribed to the accumulation of recalcitrant degradation intermediates (carbonaceous residues). In more oxidizing atmosphere (100% O2 under which less carbonaceous residues should form), the photocatalytic activity of TNP still decreased with repeating cycles of toluene degradation, whereas TNT showed no sign of deactivation. Because TNT has a highly ordered open channel structure, O2 molecules can be more easily supplied to the active sites with less mass transfer limitation, which subsequently hinders the accumulation of carbonaceous residues on TNT surface. Contrary to the case of toluene degradation, both TNT and TNP did not exhibit any significant deactivation during the photocatalytic degradation of acetaldehyde, because the generation of recalcitrant intermediates from acetaldehyde degradation is insignificant. The structural characteristics of TNT is highly advantageous in preventing the catalyst deactivation during the photocatalytic degradation of aromatic compounds. PMID:26854616

  17. The aroma of the probiotic yogurts with and without supplements

    Directory of Open Access Journals (Sweden)

    Mirjana Hruškar

    2003-07-01

    Full Text Available The purpose of this study was to establish the changes in aromacompounds of fermented milks with probiotics during storage as a function of time and temperature. The aroma compounds concentration in probiotic yogurt samples, during storage at + 4 and +20°C were studied. Acetaldehyde, diacetyl, ethanol and organic acids (lactate, acetate, citrate content were determined during 20 days, every fifth day from the beginning of storage. Acetaldehyde, ethanol, lactic, citric and acetic acid concentration were determined using an enzymatic method, while diacetyl concentration was determined using colorimetric method. The results showed that the acetaldehyde decreased during storage. The decrease was higher at elevated temperature. On the other hand, diacetyl, ethanol and acetic acid increased during storage at both temperatures. The concentration of lactic acid increased during storage at both temperature and at the end of storage it was doubled. The amount of citric acid increased in the same manner. The increase of all organic acids during storage was higher at elevated temperature.

  18. Applicability of gasoline containing ethanol as Thailand's alternative fuel to curb toxic VOC pollutants from automobile emission

    Science.gov (United States)

    Leong, Shing Tet; Muttamara, S.; Laortanakul, Preecha

    Emission rates of benzene, toluene, m-xylene, formaldehyde and acetaldehyde were measured in a fleet of 16 in-use vehicles. The test was performed on a chassis dynamometer incorporated with Bangkok Driving Cycle test mode. Three different test fuels: unleaded gasoline, gasoline blended with 10% ethanol (E10) and gasoline blended with 15% ethanol (E15) were used to determine the different compositions of exhaust emissions from various vehicles. The effects of ethanol content fuels on emissions were tested by three types of vehicles: cars with no catalytic converter installation, cars with three-way catalytic converter and cars with dual-bed catalytic converter. The test result showed wide variations in the average emission rates with different mileages, fuel types and catalytic converters (benzene: 3.33-56.48 mg/km, toluene: 8.62-124.66 mg/km, m-xylene: 2.97-51.65 mg/km, formaldehyde: 20.82-477.57 mg/km and acetaldehyde: 9.46-219.86 mg/km). There was a modest reduction in emission rate of benzene, toluene and m-xylene in cars using E10 and E15 fuels. Use of ethanol fuels, however, leads to increased formaldehyde and acetaldehyde emission rates. Our analysis revealed that alternative fuels and technologies give significant reduction in toxic VOC pollutants from automobile emission—particularly car with dual-bed catalytic converter using E10 fuel.

  19. Deodorisation effect of diamond-like carbon/titanium dioxide multilayer thin films deposited onto polypropylene

    Energy Technology Data Exchange (ETDEWEB)

    Ozeki, K., E-mail: ozeki@mx.ibaraki.ac.jp [Department of Mechanical Engineering, Ibaraki University, 4-12-1, Nakanarusawa, Hitachi, Ibaraki 316-8511 (Japan); Frontier Research Center for Applied Atomic Sciences, 162-1 Shirakata, Toukai, Ibaraki 319-1106 (Japan); Hirakuri, K.K. [Applied Systems Engineering, Graduate School of Science and Engineering, Tokyo Denki University, Ishizaka, Hatoyama, Hiki, Saitama 350-0394 (Japan); Masuzawa, T. [Department of Mechanical Engineering, Ibaraki University, 4-12-1, Nakanarusawa, Hitachi, Ibaraki 316-8511 (Japan)

    2011-04-15

    Many types of plastic containers have been used for the storage of food. In the present study, diamond-like carbon (DLC)/titanium oxide (TiO{sub 2}) multilayer thin films were deposited on polypropylene (PP) to prevent flavour retention and to remove flavour in plastic containers. For the flavour removal test, two types of multilayer films were prepared, DLC/TiO{sub 2} films and DLC/TiO{sub 2}/DLC films. The residual gas concentration of acetaldehyde, ethylene, and turmeric compounds in bottle including the DLC/TiO{sub 2}-coated and the DLC/TiO{sub 2}/DLC-coated PP plates were measured after UV radiation, and the amount of adsorbed compounds to the plates was determined. The percentages of residual gas for acetaldehyde, ethylene, and turmeric with the DLC/TiO{sub 2} coated plates were 0.8%, 65.2% and 75.0% after 40 h of UV radiation, respectively. For the DLC/TiO{sub 2}/DLC film, the percentages of residual gas for acetaldehyde, ethylene and turmeric decreased to 34.9%, 76.0% and 85.3% after 40 h of UV radiation, respectively. The DLC/TiO{sub 2}/DLC film had a photocatalytic effect even though the TiO{sub 2} film was covered with the DLC film.

  20. Variation of ambient carbonyl levels in urban Beijing between 2005 and 2012

    Science.gov (United States)

    Chen, Wentai; Shao, Min; Wang, Ming; Lu, Sihua; Liu, Ying; Yuan, Bin; Yang, Yudong; Zeng, Limin; Chen, Zhongming; Chang, Chih-Chung; Zhang, Qian; Hu, Min

    2016-03-01

    Carbonyl compounds are important precursors of secondary air pollutants. With the rapid economic development and the implementation of stricter control measures in Beijing, the sources of carbonyls possibly changed. Based on measurement data obtained at an urban site in Beijing between 2005 and 2012, we investigated annual variations in carbonyl levels and sources during these years. In summer, formaldehyde and acetaldehyde levels decreased significantly at a rate of 9.1%/year and 7.2%/year, respectively, while acetone levels increased at a rate of 4.3%/year. In winter, formaldehyde levels increased and acetaldehyde levels decreased. We also investigated the factors driving the variation in carbonyls levels during summer by determination of emission ratios for carbonyls and their precursors, and calculation of photochemical formation of carbonyls. The relative declines for primary formaldehyde and acetaldehyde levels were larger than those for secondary formation. This is possibly due to the increasing usage of natural gas and liquefied petroleum gas which could result in the rise of carbonyl precursor emission ratios. The increase in acetone levels might be related to the rising solvent usage in Beijing during these years. The influences of these sources should be paid more attention in future research.

  1. EAG and behavioral responses of Helicoverpa armigera males to volatiles from poplar leaves and their combinations with sex pheromone

    Institute of Scientific and Technical Information of China (English)

    邓建宇; 黄永平; 魏洪义; 杜家纬

    2004-01-01

    Electroantennogram (EAG) evaluation of selected compounds from wilted leaves ofblack poplar,Populus nigra,showed that phenyl acetaldehyde, methyl salicylate, (E)-2-hexenal elicited strong responses from male antennae of Helicoverpa armigera. When mixed with sex pheromone (Ph), some volatiles, e.g. phenyl acetaldehyde, benzyl alcohol,phenylethanol, methylsalicylate, linalool, benzaldehyde, (Z)-3-hexenol, (Z)-3-hexenylacetate, (Z)-6-nonenol, cineole, (E)-2-hexenal, and geraniol elicited stronger responses from male antennae than Ph alone. Wind tunnel bioassay demonstrated that various volatiles could either enhance or inhibit the effect of synthetic sex pheromone. (E)-2-hexenal, (Z)-3-hexenol and linalool in combination with Ph could not induce any male to land on source at all, whereas phenyl acetaldehyde, benzaldehyde, (Z)-6-nonenol and salicylaldehyde combined with Ph enhanced male response rates by 58.63%,50.33%, 51.85% and 127.78%, respectively, compared to Ph alone. These results suggested that some volatiles should modify sex pheromone caused behavior and that some of them could possibly be used as a tool for disrupting mating or for enhancing the effect of synthetic sex pheromone in the field.

  2. EAG and behavioral responses of Helicoverpa armigera males to volatiles from poplar leaves and their combinations with sex pheromone

    Institute of Scientific and Technical Information of China (English)

    邓建宇; 黄永平; 魏洪义

    2004-01-01

    Electroantennogram (EAG) evaluation of selected compounds from wilted leaves of black poplar, Populus nigra, showed that phenyl acetaldehyde, methyl salicylate, (E)-2-hexenal elicited strong responses from male antennae of Helicoverpa armigera. When mixed with sex pheromone (Ph), some volatiles, e.g. phenyl acetaldehyde, benzyl alcohol, phenylethanol, methylsalicylate, linalool, benzaldehyde, (Z)-3-hexenol, (Z)-3-hexenylacetate, (Z)-6-nonenol, cineole, (E)-2-hexenal, and geraniol elicited stronger responses from male antennae than Ph alone. Wind tunnel bioassay demonstrated that various volatiles could either enhance or inhibit the effect of synthetic sex pheromone. (E)-2-hexenal, (Z)-3-hexenol and linalool in combination with Ph could not induce any male to land on source at all, whereas phenyl acetaldehyde, benzaldehyde, (Z)-6-nonenol and salicylaldehyde combined with Ph enhanced male response rates by 58.63%, 50.33%, 51.85% and 127.78%, respectively, compared to Ph alone. These results suggested that some volatiles shouldmodify sex pheromone caused behavior and that some of them could possibly be used as a tool for disrupting mating or for enhancing the effect of synthetic sex pheromone in the field.

  3. Isobutanol-methanol mixtures from synthesis gas. Quarterly technical progress report, 1 January--31 March 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-20

    A series of CuMgCeO{sub x} catalysts have been prepared. Range of Cu dispersion, determined by N{sub 2}O titration, was 19-48% and are among the highest reported in the literature for Cu-based methanol and higher alcohol synthesis catalysts. Kinetics of MeOH and EtOH coupling reactions on Cu/ZnO and K-Cu/MgO/CeO{sub 2} catalysts indicate that Cu promotes alcohol dehydrogenation. Acetaldehyde is a reactive intermediate. High-pressure isobutanol synthesis studies have been carried out on K- and Cs-promoted Cu/MgO/CeO{sub 2} catalysts. The K promoter is more active than Cs for CO conversion, but the Cs promoter activates the C{sub 1} to C{sub 2} step more effectively. Catalysts with high alkali loading resulted in low conversions. Temperature programmed surface reaction studies of MeOH, EtOH, and acetaldehyde on MgO/CeO{sub 2}-based Cu catalysts show evolution of acetone, crotonaldehyde, methyl ethyl ketone, H2, carbon oxides. Neither EtOH nor acetaldehyde produces propionaldehyde or 1- propanol, suggesting that these C{sub 3} species can only form via reactions involving C{sub 1} and C{sub 2} oxygenate species.

  4. Pulse radiolysis study of the formation and the reactivity of baicalin radical anion, and in comparison with rutin, quercetin and acyrlate ester radical anions in ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Sun Gang [Department of Applied Chemistry, College of Chemical and Molecular Engineering, Peking University, Beijing 100871 (China) and Department of Internal Medicine, Division of Bioorganic Chemistry and Molecular Pharmacology, Washington University School of Medicine, St Louis, MO 63110 (United States)]. E-mail: gangsun@wustl.edu; Wang Wenfeng [Shanghai Institute of Applied Physics, Academic Sinica, P.O. Box 800-204, Shanghai 201800 (China); Wu Jilan [Department of Applied Chemistry, College of Chemical and Molecular Engineering, Peking University, Beijing 100871 (China)]. E-mail: wangwqchem@pku.edu.cn

    2007-06-15

    The reaction of solvated electrons with baicalin in N{sub 2}-saturated ethanol has been studied by pulse radiolysis. The results show that a solvated electron can add to baicalin and generate a baicalin radical anion with a maximum UV absorbance peak at 360 nm. Its molar extinction coefficient at this wavelength is 1.3x10{sup 4} M{sup -1} cm{sup -1}. The rate constant for the build-up of the baicalin radical anion is 1.3({+-}0.4)x10{sup 10} M{sup -1} s{sup -1}. Decay of the radical anion is induced by a proton transfer reaction and a recombination reaction, which involves a pseudo-first-order reaction with rate constant 2.6({+-}0.4)x10{sup 3} s{sup -1} and a second-order reaction with rate constant 1.3({+-}0.2)x10{sup 9} M{sup -1} s{sup -1}. The effect of acetaldehyde on the decay of the baicalin radical anion was also investigated. Electron transfer between the baicalin radical anion and acetaldehyde was not observed, probably due to the low rate of electron transfer between the baicalin radical anion and acetaldehyde. Reactivity of the rutin, quercetin, baicalin and ethyl acrylate radical anions are also compared.

  5. Carcinogenic compounds in alcoholic beverages: an update.

    Science.gov (United States)

    Pflaum, Tabea; Hausler, Thomas; Baumung, Claudia; Ackermann, Svenja; Kuballa, Thomas; Rehm, Jürgen; Lachenmeier, Dirk W

    2016-10-01

    The consumption of alcoholic beverages has been classified as carcinogenic to humans by the International Agency for Research on Cancer (IARC) since 1988. More recently, in 2010, ethanol as the major constituent of alcoholic beverages and its metabolite acetaldehyde were also classified as carcinogenic to humans. Alcoholic beverages as multi-component mixtures may additionally contain further known or suspected human carcinogens as constituent or contaminant. This review will discuss the occurrence and toxicology of eighteen carcinogenic compounds (acetaldehyde, acrylamide, aflatoxins, arsenic, benzene, cadmium, ethanol, ethyl carbamate, formaldehyde, furan, glyphosate, lead, 3-MCPD, 4-methylimidazole, N-nitrosodimethylamine, pulegone, ochratoxin A, safrole) occurring in alcoholic beverages as identified based on monograph reviews by the IARC. For most of the compounds of alcoholic beverages, quantitative risk assessment provided evidence for only a very low risk (such as margins of exposure above 10,000). The highest risk was found for ethanol, which may reach exposures in ranges known to increase the cancer risk even at moderate drinking (margin of exposure around 1). Other constituents that could pose a risk to the drinker were inorganic lead, arsenic, acetaldehyde, cadmium and ethyl carbamate, for most of which mitigation by good manufacturing practices is possible. Nevertheless, due to the major effect of ethanol, the cancer burden due to alcohol consumption can only be reduced by reducing alcohol consumption in general or by lowering the alcoholic strength of beverages.

  6. Exposure and inequality for select urban air pollutants in the Tampa Bay area.

    Science.gov (United States)

    Yu, Haofei; Stuart, Amy L

    2016-05-01

    Air pollution exposure has been linked to numerous adverse health effects, with some disadvantaged subgroups disproportionately burdened. The objective of this work was to characterize distributions of emissions and concentrations of a few important urban air toxics at high spatiotemporal resolution in order to assess exposure and inequality. Benzene, 1,3-butadiene, formaldehyde, and acetaldehyde were the focus pollutants, with oxides of nitrogen (NOx) estimated for comparisons. Primary pollutant emissions were estimated for the full spectrum of source types in the Tampa area using a hybrid approach that is most detailed for major roadways and includes hourly variations in vehicle speed. Resultant pollutant concentrations were calculated using the CALPUFF dispersion model, and combined with CMAQ model output to account for secondary formation of formaldehyde and acetaldehyde. Census demographic data were applied to estimate residential pollution exposures and inequality among population subgroups. Estimated concentrations of benzene, 1,3-butadiene, and NOx were generally higher in urban areas and lower in rural areas. Exposures to these pollutants were disproportionately high for subgroups characterized as black, Hispanic and low income (annual household income less than $20,000). For formaldehyde and acetaldehyde, the patterns of concentration and exposure were largely reversed. Results suggest that disparities in exposure depend on pollutant type. PMID:26895157

  7. [FTIR detection of unregulated emissions from a diesel engine with biodiesel fuel].

    Science.gov (United States)

    Tan, Pi-qiang; Hu, Zhi-yuan; Lou, Di-ming

    2012-02-01

    Biodiesel, as one of the most promising alternative fuels, has received more attention because of limited fossil fuels. A comparison of biodiesel and petroleum diesel fuel is discussed as regards engine unregulated exhaust emissions. A diesel fuel, a pure biodiesel fuel, and fuel with 20% V/V biodiesel blend ratio were tested without engine modification The present study examines six typical unregulated emissions by Fourier transform infrared spectroscopy (FTIR) method: formaldehyde (HCHO), acetaldehyde (C2 H4 O), acetone (C3 H6 O), toluene (C7 H8), sulfur dioxide (SO2), and carbon dioxide (CO2). The results show addition of biodiesel fuel increases the formaldehyde emission, and B20 fuel has little change, but the formaldehyde emission of pure biodiesel shows a clear trend of addition. Compared with the pure diesel fuel, the acetaldehyde of B20 fuel has a distinct decrease, and the acetaldehyde emission of pure biodiesel is lower than that of the pure diesel fuel at low and middle engine loads, but higher at high engine load. The acetone emission is very low, and increases for B20 and pure biodiesel fuels as compared to diesel fuel. Compared with the diesel fuel, the toluene and sulfur dioxide values of the engine show a distinct decrease with biodiesel blend ratio increasing. It is clear that the biodiesel could reduce aromatic compounds and emissions of diesel engines. The carbon dioxide emission of pure biodiesel has a little lower value than diesel, showing that the biodiesel benefits control of greenhouse gas.

  8. Improved reaction kinetics and selectivity by the TiO2-embedded carbon nanofiber support for electro-oxidation of ethanol on PtRu nanoparticles

    Science.gov (United States)

    Nakagawa, Nobuyoshi; Ito, Yudai; Tsujiguchi, Takuya; Ishitobi, Hirokazu

    2014-02-01

    The electro-oxidation of ethanol by the catalyst of PtRu nanoparticles supported on a TiO2-embedded carbon nanofiber (PtRu/TECNF), which has recently been proposed by the authors as a highly active catalyst for methanol oxidation, is investigated by cyclic voltammetry using a glassy carbon electrode and by operating a direct ethanol fuel cell (DEFC) with the catalyst. The mass activity obtained from the cyclic voltammogram for the ethanol oxidation is compared to that for the methanol oxidation reported in our recent paper. The mass activity for the ethanol oxidation is comparable or slightly higher than that for the methanol oxidation, and the relationship between the TECNF composition, i.e., the Ti/C mass ratio, and the activity are also similar to that for the methanol oxidation. A DEFC fabricated with the PtRu/TECNF shows a higher power output compared to that with the commercial PtRu/C catalyst. An analysis of the reaction products by a simple two-step reaction model reveals that the PtRu/TECNF increases the rate constant for the reaction steps from ethanol to acetaldehyde and subsequently to CO2, but decreases that from acetaldehyde to acetic acid. This means that the PtRu/TECNF improves not only the kinetics, but also the selectivity to acetaldehyde.

  9. The role of surface reactions on the active and selective catalyst design for bioethanol steam reforming

    Energy Technology Data Exchange (ETDEWEB)

    Benito, M. [Instituto de Catalisis y Petroleoquimica (CSIC), C/Marie Curie 2, Campus Cantoblanco, 28049 Madrid (Spain); Ciemat, Av. Complutense 22, 28040 Madrid (Spain); Padilla, R.; Serrano-Lotina, A.; Rodriguez, L.; Daza, L. [Instituto de Catalisis y Petroleoquimica (CSIC), C/Marie Curie 2, Campus Cantoblanco, 28049 Madrid (Spain); Brey, J.J. [Hynergreen Technologies, Av. Buhaira 2, 41018 Sevilla (Spain)

    2009-07-01

    In order to study the role of surface reactions involved in bioethanol steam reforming mechanism, a very active and selective catalyst for hydrogen production was analysed. The highest activity was obtained at 700 C, temperature at which the catalyst achieved an ethanol conversion of 100% and a selectivity to hydrogen close to 70%. It also exhibited a very high hydrogen production efficiency, higher than 4.5 mol H{sub 2} per mol of EtOH fed. The catalyst was operated at a steam to carbon ratio (S/C) of 4.8, at 700 C and atmospheric pressure. No by-products, such as ethylene or acetaldehyde were observed. In order to consider a further application in an ethanol processor, a long-term stability test was performed under the conditions previously reported. After 750 h, the catalyst still exhibited a high stability and selectivity to hydrogen production. Based on the intermediate products detected by temperature programmed desorption and reaction (TPD and TPR) experiments, a reaction pathway was proposed. Firstly, the adsorbed ethanol is dehydrogenated to acetaldehyde producing hydrogen. Secondly, the adsorbed acetaldehyde is transformed into acetone via acetic acid formation. Finally, acetone is reformed to produce hydrogen and carbon dioxide, which were the final reaction products. The promotion of such reaction sequence is the key to develop an active, selective and stable catalyst, which is the technical barrier for hydrogen production by ethanol reforming. (author)

  10. Hairpin Ribozyme Genes Curtail Alcohol Drinking: from Rational Design to in vivo Effects in the Rat.

    Science.gov (United States)

    Sapag, Amalia; Irrazábal, Thergiory; Lobos-González, Lorena; Muñoz-Brauning, Carlos R; Quintanilla, María Elena; Tampier, Lutske

    2016-07-12

    Ribozyme genes were designed to reduce voluntary alcohol drinking in a rat model of alcohol dependence. Acetaldehyde generated from alcohol in the liver is metabolized by the mitochondrial aldehyde dehydrogenase (ALDH2) such that diminishing ALDH2 activity leads to the aversive effects of blood acetaldehyde upon alcohol intake. A stepwise approach was followed to design genes encoding ribozymes targeted to the rat ALDH2 mRNA. In vitro studies of accessibility to oligonucleotides identified suitable target sites in the mRNA, one of which fulfilled hammerhead and hairpin ribozyme requirements (CGGUC). Ribozyme genes delivered in plasmid constructs were tested in rat cells in culture. While the hairpin ribozyme reduced ALDH2 activity 56% by cleavage and blockade (P < 0.0001), the hammerhead ribozyme elicited minor effects by blockade. The hairpin ribozyme was tested in vivo by adenoviral gene delivery to UChB alcohol drinker rats. Ethanol intake was curtailed 47% for 34 days (P < 0.0001), while blood acetaldehyde more than doubled upon ethanol administration and ALDH2 activity dropped 25% in liver homogenates, not affecting other ALDH isoforms. Thus, hairpin ribozymes targeted to 16 nt in the ALDH2 mRNA provide durable and specific effects in vivo, representing an improvement on previous work and encouraging development of gene therapy for alcoholism.

  11. The role of surface reactions on the active and selective catalyst design for bioethanol steam reforming

    Science.gov (United States)

    Benito, M.; Padilla, R.; Serrano-Lotina, A.; Rodríguez, L.; Brey, J. J.; Daza, L.

    In order to study the role of surface reactions involved in bioethanol steam reforming mechanism, a very active and selective catalyst for hydrogen production was analysed. The highest activity was obtained at 700 °C, temperature at which the catalyst achieved an ethanol conversion of 100% and a selectivity to hydrogen close to 70%. It also exhibited a very high hydrogen production efficiency, higher than 4.5 mol H 2 per mol of EtOH fed. The catalyst was operated at a steam to carbon ratio (S/C) of 4.8, at 700 °C and atmospheric pressure. No by-products, such as ethylene or acetaldehyde were observed. In order to consider a further application in an ethanol processor, a long-term stability test was performed under the conditions previously reported. After 750 h, the catalyst still exhibited a high stability and selectivity to hydrogen production. Based on the intermediate products detected by temperature programmed desorption and reaction (TPD and TPR) experiments, a reaction pathway was proposed. Firstly, the adsorbed ethanol is dehydrogenated to acetaldehyde producing hydrogen. Secondly, the adsorbed acetaldehyde is transformed into acetone via acetic acid formation. Finally, acetone is reformed to produce hydrogen and carbon dioxide, which were the final reaction products. The promotion of such reaction sequence is the key to develop an active, selective and stable catalyst, which is the technical barrier for hydrogen production by ethanol reforming.

  12. Structural and spectral characteristics of the cross-linked dimer derived from electrooxidation of cyclic 1,N2-propanoguanosine.

    Science.gov (United States)

    Murakami, Hiroya; Esaka, Yukihiro; Uno, Bunji

    2011-01-01

    The acetaldehyde-derived cyclic propano adduct of 2'-deoxyguanosine was easily oxidized electrochemically into the cross-linked dimer as an oxidative product. The structural and spectroscopic characteristics of the dimer were investigated by MS, (1)H and (13)C-NMR, UV, and DFT calculations. The dimer formation was inferred from a molecular ionic peak of m/z 705 ([(2M-2H)+H](+), M being the molecular weight of the monomer) on the ESI-MS spectra and the chemical formula as C(28)H(36)N(10)O(12) provided by the high-resolution ESI-MS results. The C2-N5 linkage between the two monomers in the dimer was deduced from the (1)H- and (13)C-NMR spectral results. In addition, the correlations in the 2-dimensional NMR spectra (DQF-COSY and HMBC) were consistently explained by the structure of the C2-N5 cross-linked dimer. UV spectral measurements also support the C2-N5 linking in the dimer formation. The formation of the cross-link dimer as an oxidative lesion of the acetaldehyde-derived cyclic propano adduct of guanosine is expected to interfere with DNA replication and to contribute to acetaldehyde-mediated genotoxicity.

  13. Regulation of Mitochondrial Function by Voltage Dependent Anion Channels in Ethanol Metabolism and the Warburg Effect

    Science.gov (United States)

    Lemasters, John J.; Holmuhamedov, Ekhson L.; Czerny, Christoph; Zhong, Zhi; Maldonado, Eduardo N.

    2012-01-01

    Voltage dependent anion channels (VDAC) are highly conserved proteins that are responsible for permeability of the mitochondrial outer membrane to hydrophilic metabolites like ATP, ADP and respiratory substrates. Although previously assumed to remain open, VDAC closure is emerging as an important mechanism for regulation of global mitochondrial metabolism in apoptotic cells and also in cells that are not dying. During hepatic ethanol oxidation to acetaldehyde, VDAC closure suppresses exchange of mitochondrial metabolites, resulting in inhibition of ureagenesis. In vivo, VDAC closure after ethanol occurs coordinately with mitochondrial uncoupling. Since acetaldehyde passes through membranes independently of channels and transporters, VDAC closure and uncoupling together foster selective and more rapid oxidative metabolism of toxic acetaldehyde to nontoxic acetate by mitochondrial aldehyde dehydrogenase. In single reconstituted VDAC, tubulin decreases VDAC conductance, and in HepG2 hepatoma cells, free tubulin negatively modulates mitochondrial membrane potential, an effect enhanced by protein kinase A. Tubulin-dependent closure of VDAC in cancer cells contributes to suppression of mitochondrial metabolism and may underlie the Warburg phenomenon of aerobic glycolysis. PMID:22172804

  14. Temperature and water loss affect ADH activity and gene expression in grape berry during postharvest dehydration.

    Science.gov (United States)

    Cirilli, Marco; Bellincontro, Andrea; De Santis, Diana; Botondi, Rinaldo; Colao, Maria Chiara; Muleo, Rosario; Mencarelli, Fabio

    2012-05-01

    Clusters of Aleatico wine grape were picked at 18°Brix and placed at 10, 20, or 30°C, 45% relative humidity (RH) and 1.5m/s of air flow to dehydrate the berries up to 40% of loss of initial fresh weight. Sampling was done at 0%, 10%, 20%, 30%, and 40% weight loss (wl). ADH (alcohol dehydrogenase) gene expression, enzyme activity, and related metabolites were analysed. At 10°C, acetaldehyde increased rapidly and then declined, while ethanol continued to rise. At 20°C, acetaldehyde and ethanol increased significantly with the same pattern and declined at 40%wl. At 30°C, acetaldehyde did not increase but ethanol increased rapidly already at 10%wl. At the latter temperature, a significant increase in acetic acid and ethyl acetate occurred, while at 10°C their values were low. At 30°C, the ADH activity (ethanol to acetaldehyde direction), increased rapidly but acetaldehyde did not rise because of its oxidation to acetic acid, which increased together with ethyl acetate. At 10°C, the ADH activity increased at 20%wl and continued to rise even at 40%wl, meaning that ethanol oxidation was delayed. At 20°C, the behaviour was intermediate to the other temperatures. The relative expression of the VvAdh2 gene was the highest at 10°C already at 10%wl in a synchrony with the ADH activity, indicating a rapid response likely due to low temperature. The expression subsequently declined. At 20 and 30°C, the expression was lower and increased slightly during dehydration in combination with the ADH activity. This imbalance between gene expression and ADH activity at 10°C, as well as the unexpected expression of the carotenoid cleavage dioxygenase 1 (CCD1) gene, opens the discussion on the stress sensitivity and transcription event during postharvest dehydration, and the importance of carefully monitoring temperature during dehydration.

  15. Air pollution source apportionment before, during, and after the 2008 Beijing Olympics and association of sources to aldehydes and biomarkers of blood coagulation, pulmonary and systemic inflammation, and oxidative stress in healthy young adults

    Science.gov (United States)

    Altemose, Brent A.

    Based on principal component analysis (PCA) of air pollution data collected during the Summer Olympic Games held in Beijing, China during 2008, the five source types of air pollution identified -- natural soil/road dust, vehicle and industrial combustion, vegetative burning, oil combustion, and secondary formation, were all distinctly lower during the Olympics. This was particularly true for vehicle and industrial combustion and oil combustion, and during the main games period between the opening and closing ceremonies. The reduction in secondary formation was reflective of a reduction in nitrogen oxides, but this also contributed to increased ozone concentrations during the Olympic period. Among three toxic aldehydes measured in Beijing during the same time period, only acetaldehyde had a reduction in mean concentration during the Olympic air pollution control period compared to the pre-Olympic period. Accordingly, acetaldehyde was significantly correlated with primary emission sources including vegetative burning and oil combustion, and with several pollutants emitted mainly from primary sources. In contrast, formaldehyde and acrolein increased during the Olympic air pollution control period; accordingly both were significantly correlated with ozone and with the secondary formation source type. These findings indicate primary sources may dominate for acetaldehyde while secondary sources may dominate for formaldehyde and acrolein. Biomarkers for pulmonary inflammation (exhaled breath condensate (EBC) pH, exhaled nitric oxide, and EBC nitrite) and hemostasis and blood coagulation (vWF and sCD62p) were most consistently associated with vehicle and industrial combustion, oil combustion, and vegetative burning. The systemic inflammation biomarker 8-OHdG was most consistently associated with vehicle and industrial combustion. In contrast, the associations between the biomarkers and the aldehydes were generally not significant or in the hypothesized direction, although

  16. Characterizing non-methane volatile organic compounds emissions from a swine concentrated animal feeding operation

    Science.gov (United States)

    Rumsey, Ian C.; Aneja, Viney P.; Lonneman, William A.

    2012-02-01

    Emissions of non-methane volatile organic compounds (NMVOCs) were determined from a swine concentrated animal feeding operation (CAFO) in North Carolina. NMVOCs were measured in air samples collected in SUMMA and fused-silica lined (FSL) canisters and were analyzed using a gas chromatography flame ionization detection (GC-FID) system. Measurements were made from both an anaerobic lagoon and barn in each of the four seasonal sampling periods during the period June 2007 through April 2008. In each sampling period, nine to eleven canister samples were taken from both the anaerobic lagoon and barn over a minimum of four different days during a period of ˜1 week. Measurements of meteorological and physiochemical parameters were also made during the sampling period. In lagoon samples, six NMVOCs were identified that had significantly larger emissions in comparison to other NMVOCs. This included three alcohols (ethanol, 2-ethyl-1-hexanol, and methanol), two ketones (acetone and methyl ethyl ketone (MEK)) and an aldehyde (acetaldehyde). The overall average fluxes for these NMVOCs, ranged from 0.18 μg m -2 min -1 for 2-ethyl-1-hexanol to 2.11 μg m -2 min -1 for acetone, with seasonal fluxes highest in the summer for four (acetone, acetaldehyde, 2-ethyl-1-hexanol and MEK) of the six compounds In barn samples, there were six NMVOCs that had significantly larger concentrations and emissions in comparison to other NMVOCs. These consisted of two alcohols (methanol and ethanol), an aldehyde (acetaldehyde), two ketones (acetone and 2,3-butanedione), and a phenol (4-methylphenol). Overall average barn concentration ranged from 2.87 ppb for 4-methylphenol to 16.12 ppb for ethanol. Overall average normalized barn emission rates ranged from 0.10 g day -1 AU -1 (1 AU (animal unit) = 500 kg of live animal weight) for acetaldehyde to 0.45 g day -1 AU -1 for ethanol. The NMVOCs, 4-methylphenol and 2,3-butanedione, which have low odor thresholds (odor thresholds = 1.86 ppb and 0

  17. Comparison of the impact of the Tobacco Heating System 2.2 and a cigarette on indoor air quality.

    Science.gov (United States)

    Mitova, Maya I; Campelos, Pedro B; Goujon-Ginglinger, Catherine G; Maeder, Serge; Mottier, Nicolas; Rouget, Emmanuel G R; Tharin, Manuel; Tricker, Anthony R

    2016-10-01

    The impact of the Tobacco Heating System 2.2 (THS 2.2) on indoor air quality was evaluated in an environmentally controlled room using ventilation conditions recommended for simulating "Office", "Residential" and "Hospitality" environments and was compared with smoking a lit-end cigarette (Marlboro Gold) under identical experimental conditions. The concentrations of eighteen indoor air constituents (respirable suspended particles (RSP) < 2.5 μm in diameter), ultraviolet particulate matter (UVPM), fluorescent particulate matter (FPM), solanesol, 3-ethenylpyridine, nicotine, 1,3-butadiene, acrylonitrile, benzene, isoprene, toluene, acetaldehyde, acrolein, crotonaldehyde, formaldehyde, carbon monoxide, nitrogen oxide, and combined oxides of nitrogen) were measured. In simulations evaluating THS 2.2, the concentrations of most studied analytes did not exceed the background concentrations determined when non-smoking panelists were present in the environmentally controlled room under equivalent conditions. Only acetaldehyde and nicotine concentrations were increased above background concentrations in the "Office" (3.65 and 1.10 μg/m(3)), "Residential" (5.09 and 1.81 μg/m(3)) and "Hospitality" (1.40 and 0.66 μg/m(3)) simulations, respectively. Smoking Marlboro Gold resulted in greater increases in the concentrations of acetaldehyde (58.8, 83.8 and 33.1 μg/m(3)) and nicotine (34.7, 29.1 and 34.6 μg/m(3)) as well as all other measured indoor air constituents in the "Office", "Residential" and "Hospitality" simulations, respectively.

  18. Concentrations and fluxes of biogenic volatile organic compounds above a Mediterranean macchia ecosystem in Western Italy

    Directory of Open Access Journals (Sweden)

    B. Davison

    2009-02-01

    Full Text Available Emission rates and concentrations of biogenic volatile organic compounds (BVOCs were measured at a Mediterranean coastal site at Castelporziano, approximately 25 km south-west of Rome, between 7 May and 3 June 2007, as part of the ACCENT-VOCBAS field campaign on biosphere-atmosphere interactions. Concentrations and emission rates were measured using the disjunct eddy covariance method utilizing three different proton transfer reaction mass spectrometers (PTR-MS for BVOC mixing ratio measurements and sonic anemometers for three-dimensional high-frequency wind measurements. Depending on the measurement period and the instrument, the median volume mixing ratios were 1.6–3.5 ppbv for methanol, 0.4–1.5 ppbv for acetaldehyde, 1.0–2.5 ppbv for acetone, 0.10–0.17 ppbv for isoprene, and 0.18–0.30 ppbv for monoterpenes. A diurnal cycle in mixing ratios was apparent with daytime maxima for methanol, acetaldehyde, acetone, and isoprene. The median fluxes were 370–440 μg m−2 h−1 for methanol, 180–360 μg m−2 h−1 for acetaldehyde, 180–450 μg m−2 h−1 for acetone, 71–290 μg m−2 h−1 for isoprene, and 240–860 μg m−2 h−1 for monoterpenes.

  19. Spatial distributions of and diurnal variations in low molecular weight carbonyl compounds in coastal seawater, and the controlling factors

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Kazuhiko, E-mail: takedaq@hiroshima-u.ac.jp [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan); Katoh, Shinya; Mitsui, Yumi; Nakano, Shinichi [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan); Nakatani, Nobutake [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan); Department of Environmental and Symbiotic Sciences, Rakuno Gakuen University, 582 Bunkyodai-Midorimachi, Ebetsu, Hokkaido 069-8501 (Japan); Sakugawa, Hiroshi [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan)

    2014-09-15

    We studied the spatial distributions of and the diurnal variations in four low molecular weight (LMW) carbonyl compounds, formaldehyde, acetaldehyde, propionaldehyde, and glyoxal, in coastal seawater. The samples were taken from the coastal areas of Hiroshima Bay, the Iyo Nada, and the Bungo Channel, western Japan. The formaldehyde, acetaldehyde, and glyoxal concentrations were higher in the northern part of Hiroshima Bay than at offshore sampling points in the Iyo Nada and the Bungo Channel. These three compounds were found at much higher concentrations in the surface water than in deeper water layers in Hiroshima Bay. It is noteworthy that propionaldehyde was not detected in any of the seawater samples, the concentrations present being lower than the detection limit (1 nanomole per liter (nM)) of the high performance liquid chromatography (HPLC) system we used. Photochemical and biological experiments were performed in the laboratory to help understand the characteristic distributions and fates of the LMW carbonyl compounds. The primary process controlling their fate in the coastal environment appears to be their biological consumption. The direct photo degradation of propionaldehyde, initiated by ultraviolet (UV) absorption, was observed, although formaldehyde and acetaldehyde were not degraded by UV irradiation. Our results suggest that the degradation of the LMW carbonyl compounds by photochemically formed hydroxyl radicals is relatively insignificant in the study area. Atmospheric deposition is a possible source of soluble carbonyl compounds in coastal surface seawater, but it may not influence the carbonyl concentrations in offshore waters. - Highlights: • Low molecular weight (LMW) carbonyl compounds in coastal seawater were determined. • Photochemical productions of LMW carbonyl compounds in seawater were observed. • LMW carbonyl compounds were largely consumed biologically. • Photochemical degradation was relatively insignificant in the study area.

  20. Catalysis of acetoin formation by brewers' yeast pyruvate decarboxylase isozymes.

    Science.gov (United States)

    Stivers, J T; Washabaugh, M W

    1993-12-14

    Catalysis of C(alpha)-proton transfer from 2-(1-hydroxyethyl)thiamin diphosphate (HETDP) by pyruvate decarboxylase isozymes (PDC; EC 4.1.1.1) from Saccharomyces carlsbergensis was investigated by determining the steady-state kinetics of the reaction of [1-L]acetaldehyde (L = H, D, or T) to form acetoin and the primary kinetic isotope effects on the reaction. The PDC isozyme mixture and alpha 4 isozyme (alpha 4-PDC) have different steady-state kinetic parameters and isotope effects for acetoin formation in the presence and absence of the nonsubstrate allosteric effector pyruvamide: pyruvamide activation occurs by stabilization of the acetaldehyde/PDC ternary complex. The magnitudes of primary L(V/K)-type (L = D or T) isotope effects on C(alpha)-proton transfer from alpha 4-PDC-bound HETDP provide no evidence for significant breakdown of the Swain-Schaad relationship that would indicate partitioning of the putative C(alpha)-carbanion/enamine intermediate between HETDP and products. The substrate concentration dependence of the deuterium primary kinetic isotope effects provides evidence for an intrinsic isotope effect of 4.1 for C(alpha)-proton transfer from alpha 4-PDC-bound HETDP. A 1.10 +/- 0.02-fold 14C isotope discrimination against [1,2-14C]acetaldehyde in acetoin formation is inconsistent with a stepwise mechanism, in which the addition step occurs after rate-limiting formation of the C(alpha)-carbanion/enamine as a discrete enzyme-bound intermediate, and provides evidence for a concerted reaction mechanism with an important component of carbon-carbon bond formation in the transition state.

  1. Comparison of Carbonyls and BTEX Emissions from a Light Duty Vehicle Fuelled with Gasoline and Ethanol-Gasoline Blend, and Operated without 3-Way Catalytic Converter

    Directory of Open Access Journals (Sweden)

    Asad Naeem Shah

    2011-10-01

    Full Text Available This paper presents the comparison of unregulated emissions such as carbonyls and BTEX (Benzene, Toluene, Ethyl Benzene, and Xylenes species emanated from a light duty SI (Spark Ignition vehicle E-0 (fuelled on gasoline and E-10 (ethanol-gasoline blend. Meanwhile, the ozone forming potential of these pollutants based on their ozone SR (Specific Reactivity has also been addressed in this study. The experiments were performed on transient as well as steady-state modes in accordance with the standard protocols recommended for light duty vehicle emissions. Carbonyls and BTEX were analyzed by HPLC (High Performance Liquid Chromatography with UV detector and GC/MS (Gas Chromatography/Mass Spectroscopy, respectively. Formaldehyde and acetaldehyde were the predominant components of the carbonyls for E-0 and E-10, respectively. During transient mode, formaldehyde, acrolein + acetone, and tolualdehyde pollutants were decreased but, acetaldehyde emissions increased with E-10 as compared to E-0. The BTEX emissions were also decreased with E-10, relative to E-0. During the steady-state modes, formaldehyde, acrolein + acetone and propionaldehyde were lower, aromatic aldehydes were absent, but acetaldehyde pollutants were higher with E-10 compared to E-0. The BTEX emissions were decreased at medium and higher speed modes however, increased at lower speed mode with E-10 as compared to E-0. Total BTEX emissions were maximal at lower speed mode but, least at medium speed mode for both the fuels. SR of the pollutants was higher over transient cycle of operation, compared with steady-state mode. Relative to E-0, E-10 displayed lower SR during both transient as well as steady-state mode.

  2. Light-absorbing aldol condensation products in acidic aerosols: Spectra, kinetics, and contribution to the absorption index

    Science.gov (United States)

    Nozière, Barbara; Esteve, William

    The radiative properties of aerosols that are transparent to light in the near-UV and visible, such as sulfate aerosols, can be dramatically modified when mixed with absorbing material such as soot. In a previous work we had shown that the aldol condensation of carbonyl compounds produces light-absorbing compounds in sulfuric acid solutions. In this work we report the spectroscopic and kinetic parameters necessary to estimate the effects of these reactions on the absorption index of sulfuric acid aerosols in the atmosphere. The absorption spectra obtained from the reactions of six different carbonyl compounds (acetaldehyde, acetone, propanal, butanal, 2-butanone, and trifluoroacetone) and their mixtures were compared over 190-1100 nm. The results indicated that most carbonyl compounds should be able to undergo aldol condensation. The products are oligomers absorbing light in the 300-500 nm region where few other compounds absorb, making them important for the radiative properties of aerosols. Kinetic experiments in 96-75 wt% H 2SO 4 solutions and between 273 and 314 K gave an activation energy for the rate constant of formation of the aldol products of acetaldehyde of -(70±15) kJ mol -1 in 96 wt% solution and showed that the effect of acid concentration was exponential. A complete expression for this rate constant is proposed where the absolute value in 96 wt% H 2SO 4 and at 298 K is scaled to the Henry's law coefficient for acetaldehyde and the absorption cross-section for the aldol products assumed in this work. The absorption index of stratospheric sulfuric acid aerosols after a 2-year residence time was estimated to 2×10 -4, optically equivalent to a content of 0.5% of soot and potentially significant for the radiative forcing of these aerosols and for satellite observations in channels where the aldol products absorb.

  3. Intrinsic Selectivity and Structure Sensitivity of Rhodium Catalysts for C(2+) Oxygenate Production.

    Science.gov (United States)

    Yang, Nuoya; Medford, Andrew J; Liu, Xinyan; Studt, Felix; Bligaard, Thomas; Bent, Stacey F; Nørskov, Jens K

    2016-03-23

    Synthesis gas (CO + H2) conversion is a promising route to converting coal, natural gas, or biomass into synthetic liquid fuels. Rhodium has long been studied as it is the only elemental catalyst that has demonstrated selectivity to ethanol and other C2+ oxygenates. However, the fundamentals of syngas conversion over rhodium are still debated. In this work a microkinetic model is developed for conversion of CO and H2 into methane, ethanol, and acetaldehyde on the Rh (211) and (111) surfaces, chosen to describe steps and close-packed facets on catalyst particles. The model is based on DFT calculations using the BEEF-vdW functional. The mean-field kinetic model includes lateral adsorbate-adsorbate interactions, and the BEEF-vdW error estimation ensemble is used to propagate error from the DFT calculations to the predicted rates. The model shows the Rh(211) surface to be ∼6 orders of magnitude more active than the Rh(111) surface, but highly selective toward methane, while the Rh(111) surface is intrinsically selective toward acetaldehyde. A variety of Rh/SiO2 catalysts are synthesized, tested for catalytic oxygenate production, and characterized using TEM. The experimental results indicate that the Rh(111) surface is intrinsically selective toward acetaldehyde, and a strong inverse correlation between catalytic activity and oxygenate selectivity is observed. Furthermore, iron impurities are shown to play a key role in modulating the selectivity of Rh/SiO2 catalysts toward ethanol. The experimental observations are consistent with the structure-sensitivity predicted from theory. This work provides an improved atomic-scale understanding and new insight into the mechanism, active site, and intrinsic selectivity of syngas conversion over rhodium catalysts and may also guide rational design of alloy catalysts made from more abundant elements. PMID:26958997

  4. Exploratory study on the pyrolysis and PAH emissions of polylactic acid

    Science.gov (United States)

    Chien, Yi-Chi; Liang, Chenju; Yang, Shu-hua

    2011-01-01

    The emission factors for 16 U.S. EPA priority polycyclic aromatic hydrocarbons (PAHs) from the polylactic acid (PLA) pyrolysis and the decomposition mechanism were investigated in this study. The fragments and gas compositions using on-line thermogravimetry-mass spectrometry (TG-MS) were determined. A temperature series of 7 fragments was analyzed in helium, and was found to include: m/z = 16, which may represent methane; 28, which may be carbon monoxide; 44, which may be acetaldehyde; 56, which may be methylketene, 144, which may be oligomers of lactide. In addition, there are little amount of 100, and 200 which are oligomers of lactides observed in the pyrolysis of PLA. The pyrolysis of PLA is a non-radical, backbiting ester interchange reaction involving the OH chain ends. Depending on the size of the cyclic transition state, the product can be a lactide molecule, an oligomeric ring with more than two repeat units, methylketene, or acetaldehyde. Carbon monoxide and methane are contributions from the decomposition of acetaldehyde. Experimentally, not detected (n.d.)-40.47 μg of 16 PAH emissions were determined from per gram of PLA pyrolysis. The PAH profiles showed a predominance of naphthalene (58.9%), phenanthrene (12.5%), and fluoranthene (5.9%). The total PAH emissions for PLA pyrolysis is significantly lower than the values associated with PLA combustion. From the viewpoint of air pollution control, this result suggests that pyrolysis seems a better alternative than combustion for the disposal of waste PLA. Also, since pyrolysis is the first step for an incineration process, these results can provide important information on the control of PAHs formation for a commercialized incinerator.

  5. Ethanol Enhances Hepatitis C Virus Replication through Lipid Metabolism and Elevated NADH/NAD+*

    Science.gov (United States)

    Seronello, Scott; Ito, Chieri; Wakita, Takaji; Choi, Jinah

    2010-01-01

    Ethanol has been suggested to elevate HCV titer in patients and to increase HCV RNA in replicon cells, suggesting that HCV replication is increased in the presence and absence of the complete viral replication cycle, but the mechanisms remain unclear. In this study, we use Huh7 human hepatoma cells that naturally express comparable levels of CYP2E1 as human liver to demonstrate that ethanol, at subtoxic and physiologically relevant concentrations, enhances complete HCV replication. The viral RNA genome replication is affected for both genotypes 2a and 1b. Acetaldehyde, a major product of ethanol metabolism, likewise enhances HCV replication at physiological concentrations. The potentiation of HCV replication by ethanol is suppressed by inhibiting CYP2E1 or aldehyde dehydrogenase and requires an elevated NADH/NAD+ ratio. In addition, acetate, isopropyl alcohol, and concentrations of acetone that occur in diabetics enhance HCV replication with corresponding increases in the NADH/NAD+. Furthermore, inhibiting the host mevalonate pathway with lovastatin or fluvastatin and fatty acid synthesis with 5-(tetradecyloxy)-2-furoic acid or cerulenin significantly attenuates the enhancement of HCV replication by ethanol, acetaldehyde, acetone, as well as acetate, whereas inhibiting β-oxidation with β-mercaptopropionic acid increases HCV replication. Ethanol, acetaldehyde, acetone, and acetate increase the total intracellular cholesterol content, which is attenuated with lovastatin. In contrast, both endogenous and exogenous ROS suppress the replication of HCV genotype 2a, as previously shown with genotype 1b. Conclusion: Therefore, lipid metabolism and alteration of cellular NADH/NAD+ ratio are likely to play a critical role in the potentiation of HCV replication by ethanol rather than oxidative stress. PMID:19910460

  6. Ethanol as a Prodrug: Brain Metabolism of Ethanol Mediates its Reinforcing effects

    Science.gov (United States)

    Karahanian, Eduardo; Quintanilla, María Elena; Tampier, Lutske; Rivera-Meza, Mario; Bustamante, Diego; Gonzalez-Lira, Víctor; Morales, Paola; Herrera-Marschitz, Mario; Israel, Yedy

    2011-01-01

    Backround While the molecular entity responsible for the rewarding effects of virtually all drugs of abuse is known; that for ethanol remains uncertain. Some lines of evidence suggest that the rewarding effects of alcohol are mediated not by ethanol per se but by acetaldehyde generated by catalase in the brain. However, the lack of specific inhibitors of catalase has not allowed strong conclusions to be drawn about its role on the rewarding properties of ethanol. The present studies determined the effect on voluntary alcohol consumption of two gene vectors; one designed to inhibit catalase synthesis and one designed to synthesize alcohol dehydrogenase, to respectively inhibit or increase brain acetaldehyde synthesis. Methods The lentiviral vectors, which incorporate the genes they carry into the cell genome, were: (i) one encoding a shRNA anticatalase synthesis and (ii) one encoding alcohol dehydrogenase (rADH1). These were stereotaxically microinjected into the brain ventral tegmental area (VTA) of Wistar-derived rats bred for generations for their high alcohol preference (UChB), which were allowed access to an ethanol solution and water. Results Microinjection into the VTA of the lentiviral vector encoding the anticatalase shRNA virtually abolished (-94% p<0.001) the voluntary consumption of alcohol by the rats. Conversely, injection into the VTA of the lentiviral vector coding for alcohol dehydrogenase greatly stimulated (2-3 fold p<0.001) their voluntary ethanol consumption. Conclusions The study strongly suggests that to generate reward and reinforcement, ethanol must be metabolized into acetaldehyde in the brain. Data suggest novel targets for interventions aimed at reducing chronic alcohol intake. PMID:21332529

  7. Overexpression of stress-related genes enhances cell viability and velum formation in Sherry wine yeasts.

    Science.gov (United States)

    Fierro-Risco, Jesús; Rincón, Ana María; Benítez, Tahía; Codón, Antonio C

    2013-08-01

    Flor formation and flor endurance have been related to ability by Saccharomyces cerevisiae flor yeasts to resist hostile conditions such as oxidative stress and the presence of acetaldehyde and ethanol. Ethanol and acetaldehyde toxicity give rise to formation of reactive oxygen species (ROS) and loss of cell viability. Superoxide dismutases Sod1p and Sod2p and other proteins such as Hsp12p are involved in oxidative stress tolerance. In this study, genes SOD1, SOD2, and HSP12 were overexpressed in flor yeast strains FJF206, FJF414 and B16. In the SOD1 and SOD2 transformant strains superoxide dismutases encoded by genes SOD1 and SOD2 increased their specific activity considerably as a direct result of overexpression of genes SOD1 and SOD2, indirectly, catalase, glutathione reductase, and glutathione peroxidase activities increased too. The HSP12 transformant strains showed higher levels of glutathione peroxidase and reductase activities. These transformant strains showed an increase in intracellular glutathione content, a reduction in peroxidized lipid concentration, and higher resistance to oxidative stress conditions. As a result, flor formation by these strains took place more rapidly than by their parental strains, velum being thicker and with higher percentages of viable cells. In addition, a slight decrease in ethanol and glycerol concentrations, and an increase in acetaldehyde were detected in wines matured under velum formed by transformant strains, as compared to their parental strains. In the industry, velum formed by transformant strains with increased viability may result in acceleration of both metabolism and wine aging, thus reducing time needed for wine maturation. PMID:23553032

  8. Closing the peroxy acetyl (PA radical budget: observations of acyl peroxy nitrates (PAN, PPN, and MPAN during BEARPEX 2007

    Directory of Open Access Journals (Sweden)

    B. W. LaFranchi

    2009-04-01

    Full Text Available Acyl peroxy nitrates (APNs, also known as PANs are formed from the oxidation of aldehydes and other oxygenated VOC (oVOC in the presence of NO2. Formation of APNs suppresses NOx (NOx≡NO+NO2 in urban areas and enhances NOx downwind in urban plumes, increasing the rate of ozone production throughout an urban plume. APNs also redistribute NOx on global scales, enhancing NOx and thus ozone production. There are both anthropogenic and biogenic oVOC precursors to APNs, but a detailed evaluation of their chemistry against observations has proven elusive. Here we describe measurements of PAN, PPN, and MPAN along with the majority of chemicals that participate in their production and loss, including OH, HO2, numerous oVOC, and NO2. Observations were made during the Biosphere Effects on AeRosols and Photochemistry Experiment (BEARPEX 2007 in the outflow of the Sacramento urban plume. These observations are used to evaluate a detailed chemical model of APN ratios and concentrations. We find the ratios of APNs are nearly independent of the loss mechanisms and thus an especially good test of our understanding of their sources. We show that oxidation of methylvinyl ketone, methacrolein, methyl glyoxal, biacetyl and acetaldehyde are all significant sources of the PAN+peroxy acetyl (PA radical reservoir, with methylvinyl ketone (MVK often being the primary non-acetaldehyde source. At high temperatures, oxidation of non-acetaldehyde PA radical sources contributes over 60% to the total PA production rate. An analysis of absolute APN concentrations reveals a missing APN sink that can be resolved by increasing the PA+∑RO2 rate constant by a factor of 3.

  9. Genes that modulate susceptibility for alcohol dependence

    OpenAIRE

    Caio Cesar Silva de Cerqueira; Domingos Lázaro Souza Rios

    2008-01-01

    The pathways for the metabolism of the alcohol are complex and modulated by some genes that promote response to this substance. The genes that codify the enzyme alcohol dehydrogenase (os genes ADH1B or ADH2) act in the conversion of ethanol in acetaldehyde; the enzyme aldehyde dehydrogenase (ALDH2) that converts the aldehyde into ascetic acid, and the gene that codifies the enzyme cytochrome P450, isoform 2E1 (CYP2E1), that acts generating free radicals of great importance in the induced hepa...

  10. 1,3-Butanediol Dibenzoate

    Directory of Open Access Journals (Sweden)

    Wataru Hakamata

    2016-08-01

    Full Text Available Environmentally friendly and straightforward methods for creating biofuels are required to promote biofuel use. Therefore, we present here a convenient and environmentally friendly direct self-aldol reaction of acetaldehyde in 100 mM borate buffer (pH 10 affording the dimer of 3-hydroxybutanal with a good yield. The product can be easily converted into 1,3-butanediol and its benzoate; therefore, our results will have a positive impact in the field of biochemical production from ethanol.

  11. Desidratação de etanol sobre material nanoestruturado do tipo LaSBA-15 Ethanol dehydration over LaSBA-15 nanostrutured material

    Directory of Open Access Journals (Sweden)

    Geraldo E. Luz Jr

    2010-01-01

    Full Text Available La-incorporated SBA-15 mesopourous molecular sieves (LaSBA-15 were directly synthesized with aim to convert ethanol to ethylene. The samples were characterized by XRD, XRF, nitrogen sorption and acidity, by thermodesorption of n-buthylamine. The results have indicated that all the samples have showed high ordered mesostructure with a large average pore size, and that the lanthanum incorporation has caused an increase in the acidity of the SBA-15. The LaSBA-15 samples have improved, with low deactivation rate, the conversion of the ethanol to water, ether, acetaldehyde and ethylene. In addition, they have increased the ethylene selectivity.

  12. Recent Advances in Catalytic Conversion of Ethanol to Chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Junming; Wang, Yong

    2014-04-30

    With increased availability and decreased cost, ethanol is potentially a promising platform molecule for the production of a variety of value-added chemicals. In this review, we provide a detailed summary of recent advances in catalytic conversion of ethanol to a wide range of chemicals and fuels. We particularly focus on catalyst advances and fundamental understanding of reaction mechanisms involved in ethanol steam reforming (ESR) to produce hydrogen, ethanol conversion to hydrocarbons ranging from light olefins to longer chain alkenes/alkanes and aromatics, and ethanol conversion to other oxygenates including 1-butanol, acetaldehyde, acetone, diethyl ether, and ethyl acetate.

  13. Unimolecular Gas-Phase Thermolysis of Ethyl Acetate

    DEFF Research Database (Denmark)

    Egsgaard, Helge; Carlsen, Lars

    1983-01-01

    The unimolecular gas-phase thermolysis of ethyl acetate has been investigated by the Flash-Vacuum-Thermolysis/Field-Ionization Mass Spectrometry (FVT/FI-MS) method in combination with Collision Activation (CA) mass spectrometry at 1253K. Two predominant reactions are observed: elimination...... of ethylene affording acetic acid, the latter to some extent consecutively yielding ketene, and intramolecular oxygen to oxygen ethyl group migration. Additionally minor amounts of acetaldehyde is formed. The mechanistic aspects are discussed based on 18O and 18O/ 13C labelling....

  14. Catalytic selective oxidation or oxidative functionalization of methane and ethane to organic oxygenates

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Selective oxidation or oxidative functionalization of methane and ethane by both homogeneous and heterogeneous catalysis is presented concerning: (1) selective oxidation of methane and ethane to organic oxygenates by hydrogen peroxide in a water medium in the presence of homogeneous osmium catalysts, (2) selective oxidation of methane to formaldehyde over highly dispersed iron and copper heterogeneous catalysts, (3) selective oxidation of ethane to acetaldehyde and formaldehyde over supported molybdenum catalysts, and (4) oxidative carbonylation of methane to methyl acetate over heterogeneous catalysts containing dual sites of rhodium and iron.

  15. Determination of carbonyl compounds in air by HPLC; Determinacion de compuestos carbonilicos en aire por HPLC

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, S.; Perez, R.M.; Campos, A.; Gonzalez, D.

    1995-07-01

    A method for the determination of seven carbonyl compounds in air is presented. The procedure involve sampling of air by a Sep-Pak Cartridge impregnated with 2,4-dinitrophenylhydrazine. Elution was done with 3 mL of acetonitrile and the eluate was diluted to 5 mL. The analysis was done by HPLC with UV detection and external standard method quantification. It has been achieved relative standard deviations about 5% and detection limits of 80 ng/cartridge for formaldehyde, acetaldehyde and acetoacetonitrile. Three different types of samples (rural, urban, petrol emission) were successfully analyzed. (Author) 12 refs.

  16. Physical and toxic properties of hazardous chemicals regularly stored and transported in the vicinity of nuclear installations

    International Nuclear Information System (INIS)

    This report gives a compilation of data based on information assembled by the US Nuclear Regulatory Commission and completed by the Safety and Reliability Directorate of the UK AEA, the Dutch Reactor Safety Commission, the French Atomic Energy Commission, and the CSNI Secretariat. Data sheets for a large number of hazardous chemicals are presented (from acetaldehyde to xylene), giving details of their physical and toxic properties such as: molecular weight, boiling point, vapor density, heat of vaporization, toxic concentration in air, flammability limits, toxic effects, vapor pressure data, etc.

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

    Science.gov (United States)

    Dianzani, M U

    1985-01-01

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

  18. Enhanced Acid/Base Catalysis in High Temperature Liquid Water

    Institute of Scientific and Technical Information of China (English)

    Xiu Yang LU; Qi JING; Zhun LI; Lei YUAN; Fei GAO; Xin LIU

    2006-01-01

    Two novel and environmentally benign solvent systems, organic acids-enriched high temperature liquid water (HTLW) and NH3-enriched HTLW, were developed, which can enhance the reaction rate of acid/base-catalyzed organic reactions in HTLW. We investigated the decomposition of fructose in organic acids-enriched HTLW, hydrolysis of cinnamaldehyde and aldol condensation of phenylaldehyde with acetaldehyde in NH3-enriched HTLW. The experimental results demonstrated that organic acids-enriched or NH3-enriched HTLW can greatly accelerate acid/base-catalyzed organic reactions in HTLW.

  19. Interaction between ADH1C Arg272Gln and alcohol intake in relation to breast cancer risk suggests that ethanol is the causal factor in alcohol related breast cancer

    DEFF Research Database (Denmark)

    Benzon Larsen, Signe; Vogel, Ulla Birgitte; Christensen, Jane;

    2010-01-01

    Alcohol is a risk factor for breast cancer. We wanted to determine if ADH polymorphisms which modify the rate of ethanol oxidation to acetaldehyde, were associated with breast cancer risk. We matched 809 postmenopausal breast cancer cases with 809 controls, nested within the prospective Diet......, Cancer and Health study. Among variant allele carriers of ADH1C Arg(272)Gln, alcohol intake increased the risk of breast cancer with 14% (95% CI: 1.04-1.24) per 10g alcohol/day, but not among homozygous wild type carriers (p for interaction=0.06). Thus, slow oxidation of ethanol seemed to be associated...

  20. Biomass process handbook

    Energy Technology Data Exchange (ETDEWEB)

    1983-01-01

    Descriptions are given of 42 processes which use biomass to produce chemical products. Marketing and economic background, process description, flow sheets, costs, major equipment, and availability of technology are given for each of the 42 processes. Some of the chemicals discussed are: ethanol, ethylene, acetaldehyde, butanol, butadiene, acetone, citric acid, gluconates, itaconic acid, lactic acid, xanthan gum, sorbitol, starch polymers, fatty acids, fatty alcohols, glycerol, soap, azelaic acid, perlargonic acid, nylon-11, jojoba oil, furfural, furfural alcohol, tetrahydrofuran, cellulose polymers, products from pulping wastes, and methane. Processes include acid hydrolysis, enzymatic hydrolysis, fermentation, distillation, Purox process, and anaerobic digestion.

  1. Role of Transcription Factors in Steatohepatitis and Hypertension after Ethanol: The Epicenter of Metabolism

    Directory of Open Access Journals (Sweden)

    Rais A. Ansari

    2016-06-01

    Full Text Available Chronic alcohol consumption induces multi-organ damage, including alcoholic liver disease (ALD, pancreatitis and hypertension. Ethanol and ethanol metabolic products play a significant role in the manifestation of its toxicity. Ethanol metabolizes to acetaldehyde and produces reduced nicotinamide adenine dinucleotide (NADH by cytosolic alcohol dehydrogenase. Ethanol metabolism mediated by cytochrome-P450 2E1 causes oxidative stress due to increased production of reactive oxygen species (ROS. Acetaldehyde, increased redox cellular state and ROS activate transcription factors, which in turn activate genes for lipid biosynthesis and offer protection of hepatocytes from alcohol toxicity. Sterol regulatory element binding proteins (SREBPs and peroxisome proliferator activated-receptors (PPARs are two key lipogenic transcription factors implicated in the development of fatty liver in alcoholic and non-alcoholic steatohepatitis. SREBP-1 is activated in the livers of chronic ethanol abusers. An increase in ROS activates nuclear factor erythroid-2-related factor-2 (Nrf2 and hypoxia inducible factor (HIF to provide protection to hepatocytes from ethanol toxicity. Under ethanol exposure, due to increased gut permeability, there is release of gram-negative bacteria-derived lipopolysaccharide (LPS from intestine causing activation of immune response. In addition, the metabolic product, acetaldehyde, modifies the proteins in hepatocyte, which become antigens inviting auto-immune response. LPS activates macrophages, especially the liver resident macrophages, Kupffer cells. These Kupffer cells and circulating macrophages secrete various cytokines. The level of tumor necrosis factor-α (TNFα, interleukin-1beta (IL-1β, IL-6, IL-8 and IL-12 have been found elevated among chronic alcoholics. In addition to elevation of these cytokines, the peripheral iron (Fe2+ is also mobilized. An increased level of hepatic iron has been observed among alcoholics. Increased ROS

  2. CO-laser-based photoacoustic trace-gas detection: applications in postharvest physiology

    Science.gov (United States)

    Oomens, J.; Zuckermann, H.; Persijn, S.; Parker, D. H.; Harren, F. J. M.

    1998-10-01

    A sensitive CO-laser-based photoacoustic trace-gas detector has been applied to study physiological processes in biological samples. A continuous flow-through system at atmospheric pressure leads the released trace gases from the sample to the photoacoustic resonator cells at flow rates where these processes can be studied with high time resolution. We focus here on transient effects that were found during fermentation of red bell peppers and apples, yielding in particular ethanol and acetaldehyde. Results are discussed also in the light of simultaneous O2 measurements using polarographic oxygen sensors.

  3. Teores de compostos orgânicos em cachaças produzidas na região norte fluminense - Rio de Janeiro Organic compounds contents in cachaças produced in the northern Rio de Janeiro State - RJ

    Directory of Open Access Journals (Sweden)

    Leandro Marelli de Souza

    2009-01-01

    Full Text Available This work aimed to quantify some organic compounds in "cachaças" (sugar cane spirit. The ethyl alcohol was quantified by densimetry, after distillation. The acetic acid, methyl alcohol, n-propyl alcohol, n-butyl alcohol, isobutyl alcohol, isoamyl alcohol (mixture of 2-methyl-butyl and 3-methyl-butyl, ethyl acetate and acetaldehyde were determined by gas chromatography; and the furfural, 5-hydroxy-methylfurfural and acrolein by high efficiency liquid chromatography. From the 30 samples analyzed, 63.3% showed non-conformity with national legislation regarding at least one of the analyzed components.

  4. Effects of gamma irradiation on chemical and sensory evaluation of Cabernet Sauvignon wine

    International Nuclear Information System (INIS)

    Cabernet Sauvignon wines received gamma irradiation doses of 0, 0.6, 1.2 or 2.4 KGy and were stored at 21°C for up to 18 months. As radiation dose and storage time increased, total anthocyanin concentration decreased, while color density, hue and color age increased. Acetaldehyde concentration increased with increasing radiation dose and decreased as storage time increased. Sensory evaluation indicated no difference in color or astringency, but off-flavors were detected in wines given a 2.4 KGy dose. Use of gamma irradiation to rapid age Cabernet Sauvignon wines did not appear to be feasible

  5. Micro-aerobics: when rice plants lose their resistance against oxygen

    Science.gov (United States)

    Reuss, J.; Harren, F. J. M.

    2008-10-01

    Photoacoustic determination of ethane, ethanol and acetaldehyde releases from 14 d old rice seedlings leads to the conclusion that rice seedlings start suffering significant lipid peroxidation under micro-aerobic conditions. To produce micro-aerobic conditions in otherwise normal atmospheres, the oxygen concentration has been reduced to a value between 0.3 and 0.05% (v/v). The defense of the rice seedlings against oxygenic radicals becomes insufficient under these almost anaerobic conditions. The findings presented here are relevant for the clarification of what causes non-survival of rice seedlings under prolonged submergence. Dedicated to Professor Anna Giardini, University of Rome, at her retirement.

  6. Micro-aerobics: when rice plants lose their resistance against oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Reuss, J; Harren, F J M [Life Science Trace Gas Exchange Facility, Department of Molecular and Laser Physics, University of Nijmegen, Toernooiveld I, 6525 ED Nijmegen (Netherlands)], E-mail: J.Reuss@science.ru.nl

    2008-10-15

    Photoacoustic determination of ethane, ethanol and acetaldehyde releases from 14 d old rice seedlings leads to the conclusion that rice seedlings start suffering significant lipid peroxidation under micro-aerobic conditions. To produce micro-aerobic conditions in otherwise normal atmospheres, the oxygen concentration has been reduced to a value between 0.3 and 0.05% (v/v). The defense of the rice seedlings against oxygenic radicals becomes insufficient under these almost anaerobic conditions. The findings presented here are relevant for the clarification of what causes non-survival of rice seedlings under prolonged submergence.

  7. Structural and physical effects of aroma compound binding to native starch granules

    DEFF Research Database (Denmark)

    Jørgensen, Anders Dysted; Jensen, Susanne L.; Ziegler, Gregory;

    2012-01-01

    The interaction and physical/structural effects of aroma compounds, at high concentrations on dry native starch granules were studied using eight selected model compounds: acetaldehyde, dimethyl sulphide, diacetyl, allyl isothiocyanate, ethyl butyrate, citral, octanol and butyric acid. The maize...... type. As deduced from DSC, powder XRD and SEM analyses, citral, butyric acid and octanol exerted specific effects on the starch granules manifested in local melting of crystalline layers and partial disruption of the granular meso structure. The most prominent effect was obtained with citral...

  8. Cloning and sequencing of pyruvate decarboxylase (PDC) genes from bacteria and uses therefor

    Science.gov (United States)

    Maupin-Furlow, Julie A [Gainesville, FL; Talarico, Lee Ann [Gainesville, FL; Raj, Krishnan Chandra [Tamil Nadu, IN; Ingram, Lonnie O [Gainesville, FL

    2008-02-05

    The invention provides isolated nucleic acids molecules which encode pyruvate decarboxylase enzymes having improved decarboxylase activity, substrate affinity, thermostability, and activity at different pH. The nucleic acids of the invention also have a codon usage which allows for high expression in a variety of host cells. Accordingly, the invention provides recombinant expression vectors containing such nucleic acid molecules, recombinant host cells comprising the expression vectors, host cells further comprising other ethanologenic enzymes, and methods for producing useful substances, e.g., acetaldehyde and ethanol, using such host cells.

  9. A DFT study on the Cu (1 1 1) surface for ethyl acetate synthesis from ethanol dehydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Li Ruzhen; Zhang Minhua [Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University R and D Center for Petrochemical Technology, Tianjin (China); Yu Yingzhe, E-mail: lrz1699@126.com [Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University R and D Center for Petrochemical Technology, Tianjin (China)

    2012-07-01

    Copper-based catalysts have shown excellent catalytic performances. Despite extensive studies in the field, the microscopic mechanism of ethanol dehydrogenation to ethyl acetate (EA) on Cu-based catalysts remains controversial. Aiming to provide insight into the catalytic roles of Cu, density functional theory (DFT) calculations have been performed to study the elementary reactions involved in ethanol dehydrogenation to EA on Cu surfaces. In this work, the adsorption properties of ethanol, ethoxy, acetaldehyde, acetyl and EA on the Cu (1 1 1) catalyst surface were investigated. Based on two pathways, many transition states involved are located. The results show that the route proposed by Colley is more likely to happen.

  10. 高产胞外多糖嗜热链球菌混菌培养特性研究%Study on the mixed cultivated properties of high exopolysacchride-producing Streotococcus thermophillus

    Institute of Scientific and Technical Information of China (English)

    马艳; 陈历俊; 王昌禄; 牟光庆; 陈晓璇

    2011-01-01

    探讨高产胞外多糖嗜热链球菌混菌培养的产酸、产香、产黏特性.以发酵酸度、乙醛质量浓度和黏度为综合指标,确定高产胞外多糖的嗜热链球菌(S.t.)、保加利亚乳杆菌(L.b.)、嗜酸乳杆菌(L.a.)混菌最佳培养条件为培养温度42℃,总接菌量体积分数4%,V(S.t.):V(L.b.):V(L.a.)=3:2:1.在此条件下,混菌培养可以显著地提高酸度、乙醛质量浓度、黏度、胞外多糖质量浓度、β-半乳糖苷酶酶活、蛋白酶水解能力(p<0.01).发酵过程中,胞外多糖质量浓度与黏度,β-半乳糖苷酶酶活与酸度.蛋白酶酶活与酸度、乙醛质量浓度的相关性系数很高.%The aim of this research is to study the acidity,acetaldehyde and viscosity of mixed cultivation with high exopolysaccharides-producing Streptococcus thermophilus. The optimal fermentation conditions with mixed cultivation are:42 ℃, inoculation size 4%(v/v), the strains matching ratio of high exopolysaccharides-producing Streptococcus thermophilus, Lactobacillus bulgaricus and Lactobacillus acidophilus is 3:2:1 according to acidity, content of acetaldehyde and viscosity. On this condition, mixed cultivation of Lactic acid bacteria significantly improve acidity,acetaldehyde content,viscosity, exopolysaccharide (EPS), the activity of β-galactosidase and protease (P<0.01).The correlative modulus of EPS and viscosity, the activity of β-galactosidase and acidity, the activity of protease and acidity, acetaldehyde content is high.

  11. DNA adducts-chemical addons

    OpenAIRE

    T. R. Rajalakshmi; N AravindhaBabu; Shanmugam, K. T.; Masthan, K. M. K.

    2015-01-01

    DNA adduct is a piece of DNA covalently bond to a chemical (safrole, benzopyrenediol epoxide, acetaldehyde). This process could be the start of a cancerous cell. When a chemical binds to DNA, it gets damaged resulting in abnormal replication. This could be the start of a mutation and without proper DNA repair, this can lead to cancer. It is this chemical that binds with the DNA is our prime area of concern. Instead of performing the whole body analysis for diagnosing cancer, this test could b...

  12. Levels and sources of volatile organic compounds including carbonyls in indoor air of homes of Puertollano, the most industrialized city in central Iberian Peninsula. Estimation of health risk.

    Science.gov (United States)

    Villanueva, Florentina; Tapia, Araceli; Amo-Salas, Mariano; Notario, Alberto; Cabañas, Beatriz; Martínez, Ernesto

    2015-08-01

    Twenty nine organic air pollutants including carbonyl compounds, alkanes, aromatic hydrocarbons and terpenes were measured in the indoor environment of different houses together with the corresponding outdoor measurements in Puertollano, the most industrialized city in central Iberian Peninsula. VOCs were sampled during 8 weeks using Radiello(®) passive samplers, and a questionnaire on potential VOCs sources was filled out by the occupants. The results show that formaldehyde and hexanal was the most abundant VOCs measured in indoor air, with a median concentration of 55.5 and 46.4μgm(-3), respectively followed by butanal (29.1μgm(-3)), acetone (28.4μgm(-3)) and acetaldehyde (21.4μgm(-3)). After carbonyls, n-dodecane (13.1μgm(-3)) and terpenes (α-pinene, 13.4μgm(-3) and limonene, 13.4μgm(-3)) were the compounds with higher median concentrations. The indoor/outdoor (I/O) ratios demonstrated that sources in the indoor environment are prevailing for most of the investigated VOCs especially for limonene, α-pinene, hexanal, formaldehyde, pentanal, acetaldehyde, o-xylene, n-dodecane and acetone with I/O ratio >6. Multiple linear regressions were applied to investigate the indoor VOC determinants and Spearman correlation coefficients were used to establish common sources between VOCs. Finally, the lifetime cancer risk associated to formaldehyde, acetaldehyde and benzene exposure was estimated and they varied from 7.8×10(-5) to 4.1×10(-4) for formaldehyde, from 8.6×10(-6) to 3.5×10(-5) for acetaldehyde and from 2.0×10(-6) to 1.5×10(-5) for benzene. For formaldehyde, the attributed risk in most sampled homes was two orders of magnitude higher than the one (10(-6)) proposed as acceptable by risk management bodies. PMID:26025206

  13. Eletroxidação do etanol em eletrodos de Ti/IrO2

    Directory of Open Access Journals (Sweden)

    Fidelis Carlos H.V.

    2001-01-01

    Full Text Available It has been carried out an investigation of ethanol electro-oxidation on Ti/IrO2 electrodes. The experimental results show a high selectivity towards acetaldehyde formation thus, offering potential advantages in cost and availability of raw material. It has been observed that the electrode is partially blocked by a film formed after the oxidation of the starting material which can be removed by pulse technique between RDO and RDH onset. The mechanism and the selectivity of the product formed is presented.

  14. Isolation of an Aldehyde Dehydrogenase Involved in the Oxidation of Fluoroacetaldehyde to Fluoroacetate in Streptomyces cattleya

    Science.gov (United States)

    Murphy, Cormac D.; Moss, Steven J.; O'Hagan, David

    2001-01-01

    Streptomyces cattleya is unusual in that it produces fluoroacetate and 4-fluorothreonine as secondary metabolites. We now report the isolation of an NAD+-dependent fluoroacetaldehyde dehydrogenase from S. cattleya that mediates the oxidation of fluoroacetaldehyde to fluoroacetate. This is the first enzyme to be identified that is directly involved in fluorometabolite biosynthesis. Production of the enzyme begins in late exponential growth and continues into the stationary phase. Measurement of kinetic parameters shows that the enzyme has a high affinity for fluoroacetaldehyde and glycoaldehyde, but not acetaldehyde. PMID:11571203

  15. Estimation of the Accuracy of Method for Quantitative Determination of Volatile Compounds in Alcohol Products

    CERN Document Server

    Charepitsa, S V; Zadreyko, Y V; Sytova, S N

    2016-01-01

    Results of the estimation of the precision for determination volatile compounds in alcohol-containing products by gas chromatography: acetaldehyde, methyl acetate, ethyl acetate, methanol, isopropyl alcohol, propyl alcohol, isobutyl alcohol, butyl alcohol, isoamyl alcohol are presented. To determine the accuracy, measurements were planned in accordance with ISO 5725 and held at the gas chromatograph Crystal-5000. Standard deviation of repeatability, intermediate precision and their limits are derived from obtained experimental data. The uncertainty of the measurements was calculated on the base of an "empirical" method. The obtained values of accuracy indicate that the developed method allows measurement uncertainty extended from 2 to 20% depending on the analyzed compound and measured concentration.

  16. R\\'eduction de la nuisance olfactive par oxydation photocatalytique

    CERN Document Server

    Vincent, Guillaume

    2009-01-01

    Heterogeneous photocatalysis is an interesting alternative for the purification, decontamination and smell abatment of air. In the present work, the photocatalytic oxidation of 2-butanone (MEK : methyl ethyle ketone) is investigated, this low molecular mass product being the source of serious smell pollution. The influence of light and of the pollutant concentration were investigated in an annular photoreactor. As most VOC's, the degradation rate of MEK follows a Langmuir-Hinshelwood type law. Intermediate products were analysed by GC-MD ; acetaldehyde is the dominant byproduct of the photocatalytic oxidation.

  17. The MAO-A inhibitor clorgyline reduces ethanol-induced locomotion and its volitional intake in mice.

    Science.gov (United States)

    Ledesma, Juan Carlos; Escrig, Miguel Angel; Pastor, Raúl; Aragon, Carlos M G

    2014-01-01

    Hydrogen peroxide is the co-substrate used by the enzyme catalase to form Compound I (the catalase-H2O2 system), which is the major pathway for the conversion of ethanol (EtOH) into acetaldehyde in the brain. This acetaldehyde has been involved in many of the effects of EtOH. Previous research demonstrated that treatments that change the levels of cerebral H2O2 available to catalase modulate the locomotor-stimulating effects of EtOH and its volitional intake in rodents. However, the source of H2O2 which is used by catalase to form Compound I and mediates the psychoactive actions of EtOH is unknown. One cause of the generation of H2O2 in the brain comes from the deamination of biogenic amines by the activity of MAO-A. Here we explore the consequences of the administration of the MAO-A inhibitor clorgyline on EtOH-induced locomotion and voluntary EtOH drinking. For the locomotor activity tests, we injected Swiss (RjOrl) mice intraperitoneally (IP) with clorgyline (0-10mg/kg) and later (0.5-8h) with EtOH (0-3.75 g/kg; IP). Following these treatments, mice were placed in locomotor activity chambers to measure their locomotion. For the drinking experiments, mice of the C57BL/6J strain were injected IP with clorgyline prior to offering them an EtOH (20%) solution following a drinking-in-the-dark procedure. Additional experiments were performed to assess the selectivity of this compound in altering EtOH-stimulated locomotion and EtOH intake. Moreover, we indirectly tested the ability of clorgyline to reduce brain H2O2 levels. We showed that this treatment selectively reduced EtOH-induced locomotion and its self-administration. Moreover, this compound decreased central H2O2 levels available to catalase. We suggest that H2O2 derived from the deamination of biogenic amines by the activity of MAO-A could determine the formation of brain EtOH-derived acetaldehyde. This centrally-formed acetaldehyde within the neurons of the aminergic system could play a role in the

  18. Development of metal cation compound-loaded S-doped TiO2 photocatalysts having a rutile phase under visible light

    OpenAIRE

    Ohno, T; Murakami, N.; Tsubota, T.; Nishimura, H.

    2008-01-01

    We have synthesized S (S4+)-doped TiO2 photocatalysts having a rutile phase. Rutile S-doped TiO2 photocatalysts loaded with metal ion compounds (Fe3+, Rh3+, Cu2+, Co3+, Ni2+, Cr3+) have also been prepared (S-doped TiO2-Mn+). The metal ions were adsorbed on the surfaces of S-doped TiO2 nanoparticles by impregnation methods (IM) or photodeposition methods (PH). The photocatalytic activities of S-doped TiO2 for oxidation of acetaldehyde in gas phase were drastically improved after adsorbing trea...

  19. CHANGES IN VOLATILE COMPOSITION OF KRALJEVINA WINES BY CONTROLLED MALOLACTIC FERMENTATION

    Directory of Open Access Journals (Sweden)

    Ana JEROMEL

    2008-11-01

    Full Text Available The effect of malolactic fermentation (MLF on the volatile composition of white wines made from autochtonous grape variety Kraljevina was studied by inoculation with selected lactic acid bacteria. At the end of malolactic fermentation, after the decomposition of the malic acid present in wine the non volatile compounds were analyzed by HPLC, while volatile compounds were analyzed by gas chromatography. All wines were also sensory analyzed. Results showed changes in acetaldehyde, some higher alcohols, ethyl esters, free and bound monoterpenes and some organic acids that contribute to enhance the sensory properties and quality of Kraljevina wines that underwent malolactic fermentation.

  20. [Endogenous ethanol and its possible participation in the activity of the central nervous system in healthy subjects and alcoholics].

    Science.gov (United States)

    Kudriavtsev, R V; Ushakova, M M; Nebarakova, T P; Valentik, Iu V; Ionova, K P

    1987-01-01

    Blood concentrations of endogenous ethanol (EE) reflects the effects of various psychic and medicinal impacts. EE levels in alcoholic patients depend on the severity of alcoholism, emotional status and efficacy of treatment. Actualization of the pathologic craving for alcohol and other types of emotional excitement are attended by reduced EE concentrations whereas the disactualization of the pathological craving for alcohol and relaxation increase the EE levels. Stabilization of alcoholic patients' clinical status is attended by stabilization of EE values. It is suggested that acetaldehyde acts as a modulator of catecholamine levels both in normal subjects and alcoholics ensuring connection between EE levels and the status of the central nervous system.

  1. [Endogenous ethanol in the blood and tissues of rats with hypobaric hypoxia].

    Science.gov (United States)

    Tarasov, Iu A; Ostrovskiĭ, Iu M; Satanovskaia, V I; Liopo, A V; Velichko, M G; Abakumov, G Z

    1989-01-01

    Albino male rats weighing 160-180 g were used to study the effect of short-term hypobaric hypoxia (ascent in an altitude chamber to 2500 m and 5000 m for 1 hr) on endogenous ethanol measured in blood, brain and liver; simultaneously enzymes responsible for ethanol and acetaldehyde metabolism were determined. Endogenous ethanol in blood and tissues was found to be a very sensitive marker of hypoxia which was not correlated with lactate, pyruvate, lipid peroxidation or 11-hydroxycorticosteroids. The latter parameters varied in response to severe hypoxia.

  2. Role of Transcription Factors in Steatohepatitis and Hypertension after Ethanol: The Epicenter of Metabolism

    Science.gov (United States)

    Ansari, Rais A.; Husain, Kazim; Rizvi, Syed A. A.

    2016-01-01

    Chronic alcohol consumption induces multi-organ damage, including alcoholic liver disease (ALD), pancreatitis and hypertension. Ethanol and ethanol metabolic products play a significant role in the manifestation of its toxicity. Ethanol metabolizes to acetaldehyde and produces reduced nicotinamide adenine dinucleotide (NADH) by cytosolic alcohol dehydrogenase. Ethanol metabolism mediated by cytochrome-P450 2E1 causes oxidative stress due to increased production of reactive oxygen species (ROS). Acetaldehyde, increased redox cellular state and ROS activate transcription factors, which in turn activate genes for lipid biosynthesis and offer protection of hepatocytes from alcohol toxicity. Sterol regulatory element binding proteins (SREBPs) and peroxisome proliferator activated-receptors (PPARs) are two key lipogenic transcription factors implicated in the development of fatty liver in alcoholic and non-alcoholic steatohepatitis. SREBP-1 is activated in the livers of chronic ethanol abusers. An increase in ROS activates nuclear factor erythroid-2-related factor-2 (Nrf2) and hypoxia inducible factor (HIF) to provide protection to hepatocytes from ethanol toxicity. Under ethanol exposure, due to increased gut permeability, there is release of gram-negative bacteria-derived lipopolysaccharide (LPS) from intestine causing activation of immune response. In addition, the metabolic product, acetaldehyde, modifies the proteins in hepatocyte, which become antigens inviting auto-immune response. LPS activates macrophages, especially the liver resident macrophages, Kupffer cells. These Kupffer cells and circulating macrophages secrete various cytokines. The level of tumor necrosis factor-α (TNFα), interleukin-1beta (IL-1β), IL-6, IL-8 and IL-12 have been found elevated among chronic alcoholics. In addition to elevation of these cytokines, the peripheral iron (Fe2+) is also mobilized. An increased level of hepatic iron has been observed among alcoholics. Increased ROS, IL-1

  3. Reduction of aldehydes and hydrogen cyanide yields in mainstream cigarette smoke using an amine functionalised ion exchange resin

    Directory of Open Access Journals (Sweden)

    Duke Martin G

    2011-04-01

    Full Text Available Abstract Background Cigarette smoking is a well recognized cause of diseases such as lung cancer, chronic obstructive pulmonary disease and cardiovascular disease. Of the more than 5000 identified species in cigarette smoke, at least 150 have toxicological activity. For example, formaldehyde and acetaldehyde have been assigned as Group 1 and Group 2B carcinogens by IARC, and hydrogen cyanide has been identified as a respiratory and cardiovascular toxicant. Active carbon has been shown to be an effective material for the physical adsorption of many of the smoke volatile species. However, physical adsorption of acetaldehyde, formaldehyde and also hydrogen cyanide from smoke is less effective using carbon. Alternative methods for the removal of these species from cigarette smoke are therefore of interest. A macroporous, polystyrene based ion-exchange resin (Diaion®CR20 with surface amine group functionality has been investigated for its ability to react with aldehydes and HCN in an aerosol stream, and thus selectively reduce the yields of these compounds (in particular formaldehyde in mainstream cigarette smoke. Results Resin surface chemistry was characterized using vapour sorption, XPS, TOF-SIMS and 15N NMR. Diaion®CR20 was found to have structural characteristics indicating weak physisorption properties, but sufficient surface functionalities to selectively remove aldehydes and HCN from cigarette smoke. Using 60 mg of Diaion®CR20 in a cigarette cavity filter gave reductions in smoke formaldehyde greater than 50% (estimated to be equivalent to >80% of the formaldehyde present in the smoke vapour phase independent of a range of flow rates. Substantial removal of HCN (>80% and acetaldehyde (>60% was also observed. The performance of Diaion®CR20 was found to be consistent over a test period of 6 months. The overall adsorption for the majority of smoke compounds measured appeared to follow a pseudo-first order approximation to second order

  4. Selected ion flow tube-MS analysis of headspace vapor from gastric content for the diagnosis of gastro-esophageal cancer.

    Science.gov (United States)

    Kumar, Sacheen; Huang, Juzheng; Cushnir, Julia R; Španěl, Patrik; Smith, David; Hanna, George B

    2012-11-01

    Gastric content is a complex biofluid within the human stomach which has an important role in digestive processes. It is believed that gastric content may be a contributory factor in the development of upper gastro-intestinal diseases. In this work, selected ion flow tube mass spectrometry (SIFT-MS) has been applied to the quantification of volatile organic compounds (VOCs) in the headspace vapor of gastric content samples, which were retrieved from three groups of patients, including those with gastro-esophageal cancer, noncancer diseases of the upper gastro-intestinal tract, and a healthy cohort. Twelve VOCs have been investigated in this study; the following 7 VOCs, acetone, formaldehyde, acetaldehyde, hexanoic acid, hydrogen sulphide, hydrogen cyanide, and methyl phenol, were found to be significantly different between cancer and healthy groups by the Mann-Whitney U test. Receiver operating characteristics (ROC) analysis was applied for the combined VOCs of acetaldehyde, formaldehyde, hydrogen sulphide, and methyl phenol to discriminate cancer patients from healthy controls. The area under the curve (AUC) was 0.9. This result raises the prospect that a VOC profile rather than a single biomarker may be preferable in the molecular-orientated diagnosis of gastro-oseophageal cancer, and this warrants further investigation to assess its potential application as a new diagnostic test.

  5. The sugar model: catalysis by amines and amino acid products

    Science.gov (United States)

    Weber, A. L.

    2001-01-01

    Ammonia and amines (including amino acids) were shown to catalyze the formation of sugars from formaldehyde and glycolaldehyde, and the subsequent conversion of sugars to carbonylcontaining products under the conditions studied (pH 5.5 and 50 degrees C). Sterically unhindered primary amines were better catalysts than ammonia, secondary amines, and sterically hindered primary amines (i.e. alpha-aminoisobutyric acid). Reactions catalyzed by primary amines initially consumed formaldehyde and glycolaldehyde about 15-20 times faster than an uncatalyzed control reaction. The amine-catalyzed reactions yielded aldotriose (glyceraldehyde), ketotriose (dihydroxyacetone), aldotetroses (erythrose and threose), ketotetrose (erythrulose), pyruvaldehyde, acetaldehyde, glyoxal, pyruvate, glyoxylate, and several unindentified carbonyl products. The concentrations of the carbonyl products, except pyruvate and ketotetrose, initially increased and then declined during the reaction, indicating their ultimate conversion to other products (like larger sugars or pyruvate). The uncatalyzed control reaction yielded no pyruvate or glyoxylate, and only trace amounts of pyruvaldehyde, acetaldehyde and glyoxal. In the presence of 15 mM catalytic primary amine, such as alanine, the rates of triose and pyruvaldehyde of synthesis were about 15-times and 1200-times faster, respectively, than the uncatalyzed reaction. Since previous studies established that alanine is synthesized from glycolaldehyde and formaldehyde via pyruvaldehyde as its direct precursor, the demonstration that the alanine catalyzes the conversion of glycolaldehyde and formaldehyde to pyruvaldehyde indicates that this synthetic pathway is capable of autocatalysis. The relevance of this synthetic process, named the Sugar Model, to the origin of life is discussed.

  6. Effect of calcination temperature on the photocatalytic reduction and oxidation processes of hydrothermally synthesized titania nanotubes.

    Energy Technology Data Exchange (ETDEWEB)

    Viayan, B.; Dimitrijevic, N. M.; Rajh, T.; Gray, K.; Northwestern Univ.

    2010-08-05

    Titania nanotubes having diameters 8 to 12 nm and lengths of 50-300 nm were prepared using a hydrothermal method. Further, the titania nanotubes were calcined over the temperature range 200-800 C in order to enhance their photocatalytic properties by altering their morphology. The calcined titania nanotubes were characterized by using X-ray diffraction and surface area analysis and their morphological features were studied by scanning and transmission electron microscopy. Nanotubes calcined at 400 C showed the maximum extent of photocatalyitc reduction of carbon dioxide to methane, whereas samples calcined at 600 C produced maximum photocatalytic oxidation of acetaldehyde. Electron paramagnetic resonance (EPR) spectroscopy was used to interrogate the effects of nanotube structure on the charge separation and trapping as a function of calcination temperature. EPR results indicated that undercoordinated titania sites are associated with maximum CO{sub 2} reduction occurring in nanotubes calcined at 400 C. Despite the collapse of the nantube structure to form nanorods and the concomitant loss of surface area, the enhanced charge separation associated with increased crystallinity promoted high rates of oxidation of acetaldehyde in titania materials calcined at 600 C. These results illustrate that calcination temperature allows us to tune the morphological and surface features of the titania nanostructures for particular photocatalytic reactions.

  7. Comparing the catalytic oxidation of ethanol at the solid-gas and solid-liquid interfaces over size-controlled Pt nanoparticles: striking differences in kinetics and mechanism.

    Science.gov (United States)

    Sapi, Andras; Liu, Fudong; Cai, Xiaojun; Thompson, Christopher M; Wang, Hailiang; An, Kwangjin; Krier, James M; Somorjai, Gabor A

    2014-11-12

    Pt nanoparticles with controlled size (2, 4, and 6 nm) are synthesized and tested in ethanol oxidation by molecular oxygen at 60 °C to acetaldehyde and carbon dioxide both in the gas and liquid phases. The turnover frequency of the reaction is ∼80 times faster, and the activation energy is ∼5 times higher at the gas-solid interface compared to the liquid-solid interface. The catalytic activity is highly dependent on the size of the Pt nanoparticles; however, the selectivity is not size sensitive. Acetaldehyde is the main product in both media, while twice as much carbon dioxide was observed in the gas phase compared to the liquid phase. Added water boosts the reaction in the liquid phase; however, it acts as an inhibitor in the gas phase. The more water vapor was added, the more carbon dioxide was formed in the gas phase, while the selectivity was not affected by the concentration of the water in the liquid phase. The differences in the reaction kinetics of the solid-gas and solid-liquid interfaces can be attributed to the molecular orientation deviation of the ethanol molecules on the Pt surface in the gas and liquid phases as evidenced by sum frequency generation vibrational spectroscopy.

  8. Quantification of aldehydes emissions from alternative and renewable aviation fuels using a gas turbine engine

    Science.gov (United States)

    Li, Hu; Altaher, Mohamed A.; Wilson, Chris W.; Blakey, Simon; Chung, Winson; Rye, Lucas

    2014-02-01

    In this research three renewable aviation fuel blends including two HEFA (Hydrotreated Ester and Fatty Acid) blends and one FAE (Fatty Acids Ethyl Ester) blend with conventional Jet A-1 along with a GTL (Gas To Liquid) fuel have been tested for their aldehydes emissions on a small gas turbine engine. Three strong ozone formation precursors: formaldehyde, acetaldehyde and acrolein were measured in the exhaust at different operational modes and compared to neat Jet A-1. The aim is to assess the impact of renewable and alternative aviation fuels on aldehydes emissions from aircraft gas turbine engines so as to provide informed knowledge for the future deployment of new fuels in aviation. The results show that formaldehyde was a major aldehyde species emitted with a fraction of around 60% of total measured aldehydes emissions for all fuels. Acrolein was the second major emitted aldehyde species with a fraction of ˜30%. Acetaldehyde emissions were very low for all the fuels and below the detention limit of the instrument. The formaldehyde emissions at cold idle were up to two to threefold higher than that at full power. The fractions of formaldehyde were 6-10% and 20% of total hydrocarbon emissions in ppm at idle and full power respectively and doubled on a g kg-1-fuel basis.

  9. Acetylene as Fast Food: Implications for Development of Life on Anoxic Primordial Earth and in the Outer Solar System

    Science.gov (United States)

    Oremland, Ronald S.; Voytek, Mary A.

    2008-02-01

    Acetylene occurs, by photolysis of methane, in the atmospheres of jovian planets and Titan. In contrast, acetylene is only a trace component of Earth's current atmosphere. Nonetheless, a methane-rich atmosphere has been hypothesized for early Earth; this atmosphere would also have been rich in acetylene. This poses a paradox, because acetylene is a potent inhibitor of many key anaerobic microbial processes, including methanogenesis, anaerobic methane oxidation, nitrogen fixation, and hydrogen oxidation. Fermentation of acetylene was discovered 25 years ago, and Pelobacter acetylenicus was shown to grow on acetylene by virtue of acetylene hydratase, which results in the formation of acetaldehyde. Acetaldehyde subsequently dismutates to ethanol and acetate (plus some hydrogen). However, acetylene hydratase is specific for acetylene and does not react with any analogous compounds. We hypothesize that microbes with acetylene hydratase played a key role in the evolution of Earth's early biosphere by exploiting an available source of carbon from the atmosphere and in so doing formed protective niches that allowed for other microbial processes to flourish. Furthermore, the presence of acetylene in the atmosphere of a planet or planetoid could possibly represent evidence for an extraterrestrial anaerobic ecosystem.

  10. The fermentation stress response protein Aaf1p/Yml081Wp regulates acetate production in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Christopher J Walkey

    Full Text Available The production of acetic acid during wine fermentation is a critical issue for wineries since the sensory quality of a wine can be affected by the amount of acetic acid it contains. We found that the C2H2-type zinc-finger transcription factor YML081Wp regulated the mRNA levels of ALD4 and ALD6, which encode a cytosolic acetaldehyde dehydrogenase (ACDH and a mitochondrial ACDH, respectively. These enzymes produce acetate from acetaldehyde as part of the pyruvate dehydrogenase bypass. This regulation was also reflected in the protein levels of Ald4p and Ald6p, as well as total ACDH activity. In the absence of ALD6, YML081W had no effect on acetic acid levels, suggesting that this transcription factor's effects are mediated primarily through this gene. lacZ reporter assays revealed that Yml081wp stimulates ALD6 transcription, in large part from a GAGGGG element 590 base pairs upstream of the translation start site. The non-annotated ORF YML081W therefore encodes a transcription factor that regulates acetate production in Saccharomyces cerevisiae. We propose AAF1 as a gene name for the YML081W ORF.

  11. Oxidation of rapeseed oil in waste activated bleaching earth and its effect on riboflavin production in culture of Ashbya gossypii.

    Science.gov (United States)

    Park, Enoch Y; Ming, Hwa

    2004-01-01

    Long-term behavior of rapeseed oil in waste activated bleaching earth (ABE) and the effect of this oil on riboflavin production in the culture of Ashbya gossypii were investigated. Waste ABE with 40% (w/w) rapeseed oil was stored for 80 d, and the extent of oxidation of rapeseed oil was measured by several analytical methods to determine the chemical properties of the oil at different stages of the oil deterioration process:peroxide value, acid value, concentrations of organic acids, acetaldehyde and unsaturated fatty acid, and content of polymerized triglycerides. Peroxide value, acid value, and concentrations of organic acids and acetaldehyde did not affect riboflavin production. However, the content of polymerized triglycerides markedly increased the viscosity of rapeseed oil and was the main reason for the exponential decrease in riboflavin production. A good correlation between the polymerized triglyceride content or viscosity and riboflavin production in the culture of A. gossypii using rapeseed oil as the sole carbon source was found. PMID:16233590

  12. The structure of retinal dehydrogenase type II at 2.7 A resolution: implications for retinal specificity.

    Science.gov (United States)

    Lamb, A L; Newcomer, M E

    1999-05-11

    Retinoic acid, a hormonally active form of vitamin A, is produced in vivo in a two step process: retinol is oxidized to retinal and retinal is oxidized to retinoic acid. Retinal dehydrogenase type II (RalDH2) catalyzes this last step in the production of retinoic acid in the early embryo, possibly producing this putative morphogen to initiate pattern formation. The enzyme is also found in the adult animal, where it is expressed in the testis, lung, and brain among other tissues. The crystal structure of retinal dehydrogenase type II cocrystallized with nicotinamide adenine dinucleotide (NAD) has been determined at 2.7 A resolution. The structure was solved by molecular replacement using the crystal structure of a mitochondrial aldehyde dehydrogenase (ALDH2) as a model. Unlike what has been described for the structures of two aldehyde dehydrogenases involved in the metabolism of acetaldehyde, the substrate access channel is not a preformed cavity into which acetaldehyde can readily diffuse. Retinal dehydrogenase appears to utilize a disordered loop in the substrate access channel to discriminate between retinaldehyde and short-chain aldehydes.

  13. Study of the emission of low molecular weight organic compounds of various plants

    International Nuclear Information System (INIS)

    Biogenic hydrocarbons are known to act as important precursors in tropospheric photochemical ozone formation. Large uncertainties exist about the composition of the mix of volatile organic compounds, emitted by various plant species and the respective emission rates. The emission and deposition behavior of wheat plants, as far as C2 to C9 hydrocarbons (NMHC), formaldehyde, and acetaldehyde are concerned, was studied both in the field (BIATEX experimental site, Manndorf, Bavaria) and in the laboratory. Vertical flux rates of the different compounds ranged from -4 to +4 nmol C m-2 surface area s-1. Aldehydeemission showed a seasonal trend with high rates in spring and lower towards the end of the vegetation period. Ambient temperature appears to control only the flux of ethane, ethene, propane and propene, whereas acetaldehyde emission by wheat plants as well as by Norway spruce is controlled by light. Over a spruce canopy (BIATEX experimental site Schachtenau, Bayerischer Wald, national park, FRG) the 12 most abundant NMHC exhibited no distinct diurnal cycle, and only small differences in mixing ratios were detected between two heights (31 and 51 m) revealing that the impact of the canopy on the abundances of the non-terpenoid NMHCs present in the air above the canopy was small. Aldehyde mixing ratios above a spruce canopy, however, may significantly be influenced either by direct emission of aldehydes from spruce or by production of aldehydes during photochemical degradation of precursors. (orig.). 87 refs., 4 tabs., 25 figs

  14. Effects of 20 Selected Fruits on Ethanol Metabolism: Potential Health Benefits and Harmful Impacts.

    Science.gov (United States)

    Zhang, Yu-Jie; Wang, Fang; Zhou, Yue; Li, Ya; Zhou, Tong; Zheng, Jie; Zhang, Jiao-Jiao; Li, Sha; Xu, Dong-Ping; Li, Hua-Bin

    2016-04-01

    The consumption of alcohol is often accompanied by other foods, such as fruits and vegetables. This study is aimed to investigate the effects of 20 selected fruits on ethanol metabolism to find out their potential health benefits and harmful impacts. The effects of the fruits on ethanol metabolism were characterized by the concentrations of ethanol and acetaldehyde in blood, as well as activities of alcohol dehydrogenase and acetaldehyde dehydrogenase in liver of mice. Furthermore, potential health benefits and harmful impacts of the fruits were evaluated by biochemical parameters including aspartate transaminase (AST), alanine transferase (ALT), malondialdehyde, and superoxide dismutase. Generally, effects of these fruits on ethanol metabolism were very different. Some fruits (such as Citrus limon (yellow), Averrhoa carambola, Pyrus spp., and Syzygium samarangense) could decrease the concentration of ethanol in blood. In addition, several fruits (such as Cucumis melo) showed hepatoprotective effects by significantly decreasing AST or ALT level in blood, while some fruits (such as Averrhoa carambola) showed adverse effects. The results suggested that the consumption of alcohol should not be accompanied by some fruits, and several fruits could be developed as functional foods for the prevention and treatment of hangover and alcohol use disorder. PMID:27043608

  15. Alcohol, Aldehydes, Adducts and Airways.

    Science.gov (United States)

    Sapkota, Muna; Wyatt, Todd A

    2015-11-05

    Drinking alcohol and smoking cigarettes results in the formation of reactive aldehydes in the lung, which are capable of forming adducts with several proteins and DNA. Acetaldehyde and malondialdehyde are the major aldehydes generated in high levels in the lung of subjects with alcohol use disorder who smoke cigarettes. In addition to the above aldehydes, several other aldehydes like 4-hydroxynonenal, formaldehyde and acrolein are also detected in the lung due to exposure to toxic gases, vapors and chemicals. These aldehydes react with nucleophilic targets in cells such as DNA, lipids and proteins to form both stable and unstable adducts. This adduction may disturb cellular functions as well as damage proteins, nucleic acids and lipids. Among several adducts formed in the lung, malondialdehyde DNA (MDA-DNA) adduct and hybrid malondialdehyde-acetaldehyde (MAA) protein adducts have been shown to initiate several pathological conditions in the lung. MDA-DNA adducts are pre-mutagenic in mammalian cells and induce frame shift and base-pair substitution mutations, whereas MAA protein adducts have been shown to induce inflammation and inhibit wound healing. This review provides an insight into different reactive aldehyde adducts and their role in the pathogenesis of lung disease.

  16. Low Temperature and H2 Selective Catalysts for Ethanol Steam Reforming

    Energy Technology Data Exchange (ETDEWEB)

    Roh, Hyun-Seog; Wang, Yong; King, David L.; Platon, Alex; Chin, Ya-Huei

    2006-04-01

    Supported Rh catalysts have been developed for selective H2 production at low temperatures. Ethanol dehydration is favorable over either acidic or basic supports such as γ-Al2O3 and MgAl2O4, while ethanol dehydrogenation is more favorable over neutral supports. A series of CeO2-ZrO2 supports with various CeO2/ZrO2 ratios were prepared by a co-precipitation method and Rh was impregnated on the as-synthesized support to achieve a strong metal to support interaction (SMSI). 2%Rh/Ce0.8Zr0.2O2 catalyst exhibited the highest H2 yield at 450oC among the various supported Rh catalysts evaluated in this study. This is mainly due to a favored reaction pathway via ethanol dehydrogenation to form the acetaldehyde intermediate, and both the strong interaction between Rh and Ce0.8Zr0.2O2 and the high oxygen storage capacity of Ce0.8Zr0.2O2 which favors oxidation of acetaldehyde decomposition products

  17. Glu504Lys Single Nucleotide Polymorphism of Aldehyde Dehydrogenase 2 Gene and the Risk of Human Diseases

    Directory of Open Access Journals (Sweden)

    Yan Zhao

    2015-01-01

    Full Text Available Aldehyde dehydrogenase (ALDH 2 is a mitochondrial enzyme that is known for its important role in oxidation and detoxification of ethanol metabolite acetaldehyde. ALDH2 also metabolizes other reactive aldehydes such as 4-hydroxy-2-nonenal and acrolein. The Glu504Lys single nucleotide polymorphism (SNP of ALDH2 gene, which is found in approximately 40% of the East Asian populations, causes defect in the enzyme activity of ALDH2, leading to alterations in acetaldehyde metabolism and alcohol-induced “flushing” syndrome. Evidence suggests that ALDH2 Glu504Lys SNP is a potential candidate genetic risk factor for a variety of chronic diseases such as cardiovascular disease, cancer, and late-onset Alzheimer’s disease. In addition, the association between ALDH2 Glu504Lys SNP and the development of these chronic diseases appears to be affected by the interaction between the SNP and lifestyle factors such as alcohol consumption as well as by the presence of other genetic variations.

  18. Effect of variable power levels on the yield of total aerosol mass and formation of aldehydes in e-cigarette aerosols.

    Science.gov (United States)

    Gillman, I G; Kistler, K A; Stewart, E W; Paolantonio, A R

    2016-03-01

    The study objective was to determine the effect of variable power applied to the atomizer of refillable tank based e-cigarette (EC) devices. Five different devices were evaluated, each at four power levels. Aerosol yield results are reported for each set of 25 EC puffs, as mass/puff, and normalized for the power applied to the coil, in mass/watt. The range of aerosol produced on a per puff basis ranged from 1.5 to 28 mg, and, normalized for power applied to the coil, ranged from 0.27 to 1.1 mg/watt. Aerosol samples were also analyzed for the production of formaldehyde, acetaldehyde, and acrolein, as DNPH derivatives, at each power level. When reported on mass basis, three of the devices showed an increase in total aldehyde yield with increasing power applied to the coil, while two of the devices showed the opposite trend. The mass of formaldehyde, acetaldehyde, and acrolein produced per gram of total aerosol produced ranged from 0.01 to 7.3 mg/g, 0.006 to 5.8 mg/g, and aerosols from specific devices, and were compared to estimated exposure from consumption of cigarettes, to occupational and workplace limits, and to previously reported results from other researchers. PMID:26743740

  19. Influence of ethanol-gasoline blended fuel on emission characteristics from a four-stroke motorcycle engine.

    Science.gov (United States)

    Jia, Li-Wei; Shen, Mei-Qing; Wang, Jun; Lin, Man-Qun

    2005-08-31

    Emission characteristics from a four-stroke motorcycle engine using 10% (v/v) ethanol-gasoline blended fuel (E10) were investigated at different driving modes on the chassis dynamometers. The results indicate that CO and HC emissions in the engine exhaust are lower with the operation of E10 as compared to the use of unleaded gasoline, whereas the effect of ethanol on NO(X) emission is not significant. Furthermore, species of both unburned hydrocarbons and their ramifications were analyzed by the combination of gas chromatography/mass spectrometry (GC/MS) and gas chromatography/flame ionization detection (GC/FID). This analysis shows that aromatic compounds (benzene, toluene, xylene isomers (o-xylene, m-xylene and p-xylene), ethyltoluene isomers (o-ethyltoluene, m-ethyltoluene and p-ethyltoluene) and trimethylbenzene isomers (1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene and 1,3,5-trimethylbenzene)) and fatty group ones (ethylene, methane, acetaldehyde, ethanol, butene, pentane and hexane) are major compounds in motorcycle engine exhaust. It is found that the E10-fueled motorcycle engine produces more ethylene, acetaldehyde and ethanol emissions than unleaded gasoline engine does. The no significant reduction of aromatics is observed in the case of ethanol-gasoline blended fuel. The ethanol-gasoline blended fuel can somewhat improve emissions of the rest species. PMID:15923082

  20. Ambient measurements of aromatic and oxidized VOCs by PTR-MS and GC-MS: intercomparison between four instruments in a boreal forest in Finland

    Directory of Open Access Journals (Sweden)

    M. K. Kajos

    2015-04-01

    Full Text Available Proton transfer reaction mass spectrometry (PTR-MS and gas chromatography mass spectrometry GC-MS allow real-time measurements of various atmospheric volatile organic compounds (VOC. By taking parallel measurements in ambient conditions, two PTR-MSs and two GC-MSs were studied for their ability to measure methanol, acetaldehyde, acetone, benzene and toluene. The measurements were conducted at a rural boreal forest site in southern Finland between 13 April and 14 May 2012. This paper presents correlations and possible biases between the concentrations measured using the four instruments. This paper presents correlations and possible biases between the concentrations measured using the four instruments. A very good correlation was found for benzene and acetone measurements between all instruments (the mean R value was 0.88 for both compounds, while for acetaldehyde and toluene the correlation was weaker (with a mean R value of 0.50 and 0.62, respectively. For some compounds, notably for methane, there were considerable systematic differences in the mixing ratios measured by the different instruments, despite the very good correlation between the instruments (mean R = 0.90. The systematic difference arises as a difference in the linear regression slope between measurements conducted between instruments, rather than as an offset. This mismatch indicates that the systematic uncertainty in the sensitivity of a given instrument can lead to an uncertainty of 50–100% in the methanol emissions measured by commonly used methods.

  1. Homogeneous catalytic hydrogenation of bio-oil and related model aldehydes with RuCl{sub 2}(PPh{sub 3}){sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Huang, F.; Li, W.; Lu, Q.; Zhu, X. [Anhui Province Key Laboratory of Biomass Clean Energy, University of Science and Technology of China, Hefei (China)

    2010-12-15

    A homogeneous RuCl{sub 2}(PPh{sub 3}){sub 3} catalyst was prepared for the hydrogenation of bio-oil to improve its stability and fuel quality. Experiments were first performed on three model aldehydes of acetaldehyde, furfural and vanillin selected to represent the linear aldehydes, oxygen heterocyclic aldehydes and aromatic aldehydes in bio-oil. The results demonstrated the high hydrogenation capability of this homogeneous catalyst under mild conditions (55-90 C, 1.3-3.3 MPa). The highest conversion of the three model aldehydes was over 90 %. Furfural and acetaldehyde were singly converted to furfuryl alcohol and ethanol after hydrogenation, while vanillin was mainly converted to vanillin alcohol, together with a small amount of 2-methoxy-4-methylphenol and 2-methoxyphenol. Further experiments were conducted on a bio-oil fraction extracted by ethyl acetate and on the whole bio-oil at 70 C and 3.3 MPa. Most of the aldehydes were transformed to the corresponding alcohols, and some ketones and compounds with C-C double bond were converted to more stable compounds. (Copyright copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. HPLC-MS determination of the oxidation products of the reaction between alpha- and beta-pinene and OH radicals.

    Science.gov (United States)

    Van den Bergh, V; Coeckelberghs, H; Vanhees, I; De Boer, R; Compernolle, F; Vinckier, C

    2002-03-01

    Biogenic non-methane hydrocarbons such as isoprene, alpha-pinene, and beta-pinene, are emitted by forests in very large quantities. To evaluate the role of alpha- and beta-pinene and their contribution to the global production of trace gases and especially aerosol precursors, a study of the oxidation mechanism of alpha- and beta-pinene with hydroxyl radicals must be conducted. The degradation products of both monoterpenes with hydroxyl radicals were identified and quantified in a fast-flow reactor. The products were collected on a liquid-nitrogen trap coated with a 2,4-DNPH solution to which two internal standards (benzaldehyde-2,4-DNPH and tolualdehyde-2,4-DNPH) had been added. The collection method was based on the in situ conversion of aldehyde and/or ketone compounds to their 2,4-dinitrophenylhydrazone derivatives. The derivatives were analyzed by HPLC-MS using APCI(-). TIC chromatograms and mass spectral data for the various oxidation products are presented. For alpha-pinene, pinonaldehyde is the most important degradation product, with smaller amounts of acetone, formaldehyde, campholenealdehyde, and acetaldehyde. For beta-pinene, nopinone and formaldehyde are the most abundant products, of almost equal importance, whereas acetone and acetaldehyde are minor compounds.

  3. The activity of class I, II, III and IV of alcohol dehydrogenase (ADH) isoenzymes and aldehyde dehydrogenase (ALDH) in brain cancer.

    Science.gov (United States)

    Laniewska-Dunaj, Magdalena; Jelski, Wojciech; Orywal, Karolina; Kochanowicz, Jan; Rutkowski, Robert; Szmitkowski, Maciej

    2013-07-01

    The brain being highly sensitive to the action of alcohol is potentially susceptible to its carcinogenic effects. Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) are the main enzymes involved in ethanol metabolism, which leads to the generation of carcinogenic acetaldehyde. Human brain tissue contains various ADH isoenzymes and possess also ALDH activity. The purpose of this study was to compare the capacity for ethanol metabolism measured by ADH isoenzymes and ALDH activity in cancer tissues and healthy brain cells. The samples were taken from 62 brain cancer patients (36 glioblastoma, 26 meningioma). For the measurement of the activity of class I and II ADH isoenzymes and ALDH activity, the fluorometric methods were used. The total ADH activity and activity of class III and IV isoenzymes were measured by the photometric method. The total activity of ADH, and activity of class I ADH were significantly higher in cancer cells than in healthy tissues. The other tested classes of ADH and ALDH did not show statistically significant differences of activity in cancer and in normal cells. Analysis of the enzymes activity did not show significant differences depending on the location of the tumor. The differences in the activity of total alcohol dehydrogenase, and class I isoenzyme between cancer tissues and healthy brain cells might be a factor for metabolic changes and disturbances in low mature cancer cells and additionally might be a reason for higher level of acetaldehyde which can intensify the carcinogenesis.

  4. Ethylene-responsive transcription factors interact with promoters of ADH and PDC involved in persimmon (Diospyros kaki) fruit de-astringency.

    Science.gov (United States)

    Min, Ting; Yin, Xue-ren; Shi, Yan-na; Luo, Zheng-rong; Yao, Yun-cong; Grierson, Donald; Ferguson, Ian B; Chen, Kun-song

    2012-11-01

    The persimmon fruit is a particularly good model for studying fruit response to hypoxia, in particular, the hypoxia-response ERF (HRE) genes. An anaerobic environment reduces fruit astringency by converting soluble condensed tannins (SCTs) into an insoluble form. Although the physiology of de-astringency has been widely studied, its molecular control is poorly understood. Both CO(2) and ethylene treatments efficiently removed the astringency from 'Mopan' persimmon fruit, as indicated by a decrease in SCTs. Acetaldehyde, the putative agent for causing de-astringency, accumulated during these treatments, as did activities of the key enzymes of acetaldehyde synthesis, alcohol dehydrogenase (ADH), and pyruvate decarboxylase (PDC). Eight DkADH and DkPDC genes were isolated, and three candidates for a role in de-astringency, DkADH1, DkPDC1, and DkPDC2, were characterized by transcriptional analysis in different tissues. The significance of these specific isoforms was confirmed by principal component analysis. Transient expression in leaf tissue showed that DkPDC2 decreased SCTs. Interactions of six hypoxia-responsive ERF genes and target promoters were tested in transient assays. The results indicated that two hypoxia-responsive ERF genes, DkERF9 and DkERF10, were involved in separately regulating the DkPDC2 and DkADH1 promoters. It is proposed that a DkERF-DkADH/DkPDC cascade is involved in regulating persimmon de-astringency.

  5. VAPOR-PHASE CATALYTIC CONVERSION OF ETHANOL INTO 1,3-BUTADIENE ON Cr-Ba/MCM-41 CATALYSTS

    Directory of Open Access Journals (Sweden)

    N. La-Salvia

    2015-06-01

    Full Text Available AbstractAl-MCM-41, 16%Ba/Al-MCM-41 and 1.4%Cr-16%Ba/Al-MCM-41 were used as catalysts in the vapor-phase catalytic conversion of ethanol. Physical-chemical properties of the catalysts and the effect of barium and chromium on the Al-MCM-41 activity and 1,3-butadiene yield were studied. The catalysts were characterized by X-ray diffraction (XRD, N2 physisorption (BET method, CO2chemisorption and Fourier transform infrared spectroscopy (FT-IR. When ethanol was completely converted on Al-MCM-41 and 16%Ba/Al-MCM-41, the reaction products showed a high selectivity for ethylene (90-98%. However, on the 1.4%Cr-16%Ba/Al-MCM-41 catalyst, a greater number of reaction products were obtained such as ethylene, acetaldehyde, diethyl ether and 1,3-butadiene. The maximum 1,3-butadiene yield obtained from ethanol reaction was 25% at 723 K and W/FEtOH = 15 g h mol-1. The latter result was obtained in a single step and without addition of reaction promoters (e.g., acetaldehyde, crotonaldehyde, hydrogen in the feed stream to the reactor.

  6. Effect of Nitric Oxide on Alcoholic Fermentation and Qualities of Chinese Winter Jujube During Storage

    Institute of Scientific and Technical Information of China (English)

    SUN Li-na; LIU Meng-chen; ZHU Shu-hua; ZHOU Jie; WANG Ming-lin

    2007-01-01

    This article investigates the effects of nitric oxide (NO) on alcoholic fermentation and the qualities of Chinese Winter Jujube during storage, and explores the action mechanisms of browning and softening of fruits to provide theoretical proofs for using NO in the storage of Chinese Winter Jujube. Chinese Winter Jujube fruits were fumigated with different concentrations of NO gas (0, 10, 20, 30 μL L-1) under anaerobic conditions and stored at 22 ± 1 ℃ and 4 ± 1 ℃. The changes in appearance qualities, the contents of pyruvate, ethanol, acetaldehyde, and the activities of alcohol dehydrogenase (ADH) and lactate dehydrogenase (LDH) were investigated. The contents of pyruvate, ethanol, and acetaldehyde were significantly reduced, and the peak of pyruvate content was delayed by 20 μL L-1 NO. The activities of ADH and LDH in 20 μL L-1 NO treated fruits were also significantly inhibited. However, the alcoholic fermentation and softening of Chinese Winter Jujube fruits were promoted by 30 μL L-1 NO during storage. The results indicated that 20 μL L-1 NO could mitigate the injury of ethanol on Chinese Winter Jujube and effectively delay the browning and softening of fruits during storage.

  7. Homolytic cleavage C-C bond in the electrooxidation of ethanol and bioethanol

    Science.gov (United States)

    Barroso, J.; Pierna, A. R.; Blanco, T. C.; Morallón, E.; Huerta, F.

    Nowadays, the studies are focused on the search of better electrocatalysts that promote the complete oxidation of ethanol/bioethanol to CO 2. To that end, amorphous bi-catalytic catalysts of composition Ni 59Nb 40Pt 1- xY x (Y = Cu, Ru, x = 0.4% at.) have been developed, obtained by mechanical alloying, resulting in higher current densities and an improvement in tolerance to adsorbed CO vs. Ni 59Nb 40Pt 1 catalyst. By using voltammetric techniques, the appearance of three oxidation peaks can be observed. The first peak could be associated with the electrooxidative process of ethanol/bioethanol to acetaldehyde, the second peak could be the oxidation of acetaldehyde to acetic acid, and the last peak might be the final oxidation to CO 2. Chrono-amperometric experiments show qualitative poisoning of catalytic surfaces. However, the in situ Fourier Transformed Infrared Spectroscopy, FTIR, is used for the quasi-quantitative determination with which can be observed the appearance and evolution of different vibrational bands of carbonyl and carboxylic groups of different species, as it moves towards anodic potential in the electrooxidative process.

  8. Solvent-derived protons in catalysis by brewers' yeast pyruvate decarboxylase.

    Science.gov (United States)

    Harris, T K; Washabaugh, M W

    1995-10-31

    Catalysis of proton transfer to thiamin diphosphate (TDP) and 2-(1-hydroxyethyl)thiamin diphosphate (HETDP) by pyruvate decarboxylase isozymes (PDC; EC 4.1.1.1) from Saccharomyces carlsbergensis was investigated by determining the solvent discrimination tritium isotope effect, (kH/kT)disc, on the reaction of pyruvate to form acetaldehyde in the presence of the nonsubstrate allosteric effector pyruvamide. The fractionation factors for TDP C(2)-L (phi C(2) = 0.98 +/- 0.06) and HETDP C(alpha)-L (phi C(alpha) = 1.01 +/- 0.07) (L = H or D) do not contribute significantly to observed enzymic isotopic discrimination. The value of (kH/kT)disc = 1.0 for reprotonation of TDP C(2)-L under single-turnover conditions ([E] > [S]) is consistent with C(2)-hydron transfer via a catalytic group (phi = 1) equilibrated with solvent. [1-L]Acetaldehyde formation under transient steady-state ([E] or = 1.2) provides significant intramolecular catalysis in the enzyme-bound coenzyme.

  9. Carbonyl species characteristics during the evaporation of essential oils

    Science.gov (United States)

    Chiang, Hsiu-Mei; Chiu, Hua-Hsien; Lai, Yen-Ming; Chen, Ching-Yen; Chiang, Hung-Lung

    2010-06-01

    Carbonyls emitted from essential oils can affect the air quality when they are used in indoors, especially under poor ventilation conditions. Lavender, lemon, rose, rosemary, and tea tree oils were selected as typical and popular essential oils to investigate in terms of composition, thermal characteristics and fifteen carbonyl constituents. Based on thermogravimetric (TG) analysis, the activation energy was 7.6-8.3 kcal mol -1, the reaction order was in the range of 0.6-0.7 and the frequency factor was 360-2838 min -1. Formaldehyde, acetaldehyde, acetone, and propionaldehyde were the dominant carbonyl compounds, and their concentrations were 0.034-0.170 ppm. The emission factors of carbonyl compounds were 2.10-3.70 mg g -1, and acetone, propionaldehyde, acetaldehyde, and formaldehyde accounted for a high portion of the emission factor of carbonyl compounds in essential oil exhaust. Some unhealthy carbonyl species such as formaldehyde and valeraldehyde, were measured at low-temperature during the vaporization of essential oils, indicating a potential effect on indoor air quality and human health.

  10. Fermented probiotic beverages based on acid whey

    Directory of Open Access Journals (Sweden)

    Katarzyna Skryplonek

    2015-12-01

    Full Text Available Background. Production of fermented probiotic beverages can be a good method for acid whey usage. The obtained products combine a high nutritional value of whey with health benefits claimed for probiotic bac- teria. The aim of the study was to define quality properties of beverages based on fresh acid whey and milk with addition of buttermilk powder or sweet whey powder. Material and methods. Samples were inoculated with two strains of commercial probiotic cultures: Lac- tobacillus acidophilus La-5 or Bifidobacterium animalis Bb-12. After fermentation, samples were stored at refrigerated conditions. After 1, 4, 7, 14 and 21 days sensory characteristics, hardness, acetaldehyde content, titratable acidity, pH acidity and count of bacteria cells were evaluated. Results. Throughout all storage period, the number of bacteria was higher than 8 log cfu/ml in the all sam- ples. Beverages with La-5 strain had higher hardness and acidity, whilst samples with Bb-12 contained more acetaldehyde. Samples with buttermilk powder had better sensory properties than with sweet whey powder. Conclusions. Obtained products made of acid whey combined with milk and fortified with buttermilk pow- der or sweet whey powder, are good medium for growth and survival of examined probiotic bacteria strains. The level of bacteria was sufficient to provide health benefits to consumers.

  11. Bioethanol/gasoline blends for fuelling conventional and hybrid scooter. Regulated and unregulated exhaust emissions

    Science.gov (United States)

    Costagliola, Maria Antonietta; Prati, Maria Vittoria; Murena, Fabio

    2016-05-01

    The aim of this experimental activity was to evaluate the influence of ethanol fuel on the pollutant emissions measured at the exhaust of a conventional and a hybrid scooter. Both scooters are 4-stroke, 125 cm3 of engine capacity and Euro 3 compliant. They were tested on chassis dynamometer for measuring gaseous emissions of CO, HC, NOx, CO2 and some toxic micro organic pollutants, such as benzene, 1,3-butadiene, formaldehyde and acetaldehyde. The fuel consumption was estimated throughout a carbon balance on the exhaust species. Moreover, total particles number with diameter between 20 nm up to 1 μm was measured. Worldwide and European test cycles were carried out with both scooters fuelled with gasoline and ethanol/gasoline blends (10/90, 20/80 and 30/70% vol). According to the experimental results relative to both scooter technologies, the addiction of ethanol in gasoline reduces CO and particles number emissions. The combustion of conventional scooter becomes unstable when a percentage of 30%v of bioethanol is fed; as consequence a strong increasing of hydrocarbon is monitored, including carcinogenic species. The negative effects of ethanol fuel are related to the increasing of fuel consumption due to the less carbon content for volume unit and to the increasing of formaldehyde and acetaldehyde due to the higher oxygen availability. Almost 70% of Ozone Formation Potential is covered by alkenes and aromatics.

  12. Unregulated emissions from light-duty hybrid electric vehicles

    Science.gov (United States)

    Suarez-Bertoa, R.; Astorga, C.

    2016-07-01

    The number of registrations of light duty hybrid electric vehicles has systematically increased over the last years and it is expected to keep growing. Hence, evaluation of their emissions becomes very important in order to be able to anticipate their impact and share in the total emissions from the transport sector. For that reason the emissions from a Euro 5 compliant hybrid electric vehicle (HV2) and a Euro 5 plug-in hybrid electric vehicle (PHV1) were investigated with special interest on exhaust emissions of ammonia, acetaldehyde and ethanol. Vehicles were tested over the World harmonized Light-duty Test Cycle (WLTC) at 23 and -7 °C using two different commercial fuels E5 and E10 (gasoline containing 5% and 10% vol/vol of ethanol, respectively). PHV1 resulted in lower emissions than HV2 due to the pure electric strategy used by the former. PHV1 and HV2 showed lower regulated emissions than conventional Euro 5 gasoline light duty vehicles. However, emissions of ammonia (2-8 and 6-15 mg km-1 at 22 and -7 °C, respectively), ethanol (0.3-0.8 and 2.6-7.2 mg km-1 at 22 and -7 °C, respectively) and acetaldehyde (∼0.2 and 0.8-2.7 mg km-1 at 22 and -7 °C, respectively) were in the same range of those recently reported for conventional gasoline light duty vehicles.

  13. Does acute exposure to aldehydes impair pulmonary function and structure?

    Science.gov (United States)

    Abreu, Mariana de; Neto, Alcendino Cândido; Carvalho, Giovanna; Casquillo, Natalia Vasconcelos; Carvalho, Niedja; Okuro, Renata; Ribeiro, Gabriel C Motta; Machado, Mariana; Cardozo, Aléxia; Silva, Aline Santos E; Barboza, Thiago; Vasconcellos, Luiz Ricardo; Rodrigues, Danielle Araujo; Camilo, Luciana; Carneiro, Leticia de A M; Jandre, Frederico; Pino, Alexandre V; Giannella-Neto, Antonio; Zin, Walter A; Corrêa, Leonardo Holanda Travassos; Souza, Marcio Nogueira de; Carvalho, Alysson R

    2016-07-15

    Mixtures of anhydrous ethyl alcohol and gasoline substituted for pure gasoline as a fuel in many Brazilian vehicles. Consequently, the concentrations of volatile organic compounds (VOCs) such as ketones, other organic compounds, and particularly aldehydes increased in many Brazilian cities. The current study aims to investigate whether formaldehyde, acetaldehyde, or mixtures of both impair lung function, morphology, inflammatory and redox responses at environmentally relevant concentrations. For such purpose, C57BL/6 mice were exposed to either medical compressed air or to 4 different mixtures of formaldehyde and acetaldehyde. Eight hours later animals were anesthetized, paralyzed and lung mechanics and morphology, inflammatory cells and IL-1β, KC, TNF-α, IL-6, CCL2, MCP-1 contents, superoxide dismutase and catalalase activities were determined. The extra pulmonary respiratory tract was also analyzed. No differences could be detected between any exposed and control groups. In conclusion, no morpho-functional alterations were detected in exposed mice in relation to the control group. PMID:27102012

  14. Dehydration and Dehydrogenation of Ethylene Glycol on Rutile TiO2(110)

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhenjun; Kay, Bruce D.; Dohnalek, Zdenek

    2013-08-07

    The interactions of ethylene glycol (EG) with partially reduced rutile TiO2(110) surface have been studied using temperature programmed desorption (TPD). The saturation coverage on the surface Ti rows is determined to be 0.43 monolayer (ML), slightly less than one EG per two Ti sites. Most of the adsorbed ethanol (~80%) undergoes further reactions to other products. Two major channels are observed, dehydration yielding ethylene and water and dehydrogenation yielding acetaldehyde and hydrogen. Hydrogen formation is rather surprising as it has not been observed previously on TiO2(110) from simple organic molecules. The coverage dependent yields of ethylene and acetaldehyde correlate well with that of water and hydrogen, respectively. Dehydration dominates at lower EG coverages (< 0.2 ML) and plateaus as the coverage is increased to saturation. Dehydrogenation is observed primarily at higher EG coverages (>0.2 ML). Our results suggest that the observed dehydration and dehydrogenation reactions proceed via different surface intermediates.

  15. 顶空-GC/FID测定水中乙醛丙烯腈吡啶

    Institute of Scientific and Technical Information of China (English)

    张琢; 谷宇

    2015-01-01

    We successfully build a standard analytical method for the detection of acetaldehyde, acrylonitrile, and pyridine in water using gas chromatography-flame ionization detector (GC-FID).Three samples with concentration of 0.005 mg/L, 0.05 mg/L and 0.50mg/L were analyzed and showed a high recovery rate between 82%and 98%and a low relative standard deviation from 2.4%to 5.0%. These results confirm that this method has high accuracy, high precision and high reproducibility, which, consequently, is appropriate for detecting and analyzing acetaldehyde, acrylonitrile, and pyridine in water.%建立了顶空-气相色谱-氢火焰离子化检测器(GC-FID)检测水中乙醛丙烯腈吡啶的方法。根据加标浓度为0.005mg/L、0.05mg/L和0.50mg/L,回收率在82-98%之间,相对标准偏差为2.4-5.0%之间的测定结果,说明该方法准确度高、精确性高、重现性良好,符合水质测定乙醛丙烯腈吡啶的分析。

  16. Analysis of the Volatile Constituents of Irradiated Apple Juice

    International Nuclear Information System (INIS)

    The organoleptic studies and wholesomeness tests that are being carried out as part of the International Programme on the Irradiation of Fruit and Fruit Juices (Seibersdorf Project) entail analysis of the aromatic substances present in irradiated and non-irradiated juice. The volatile substances present in irradiated fruit juices were analysed by gas chromatography, with direct injection of the emitted vapours at ambient temperature and at 60°C (Weurman's Head Space Technique). The volatile constituents were identified by comparing the amounts retained in the column with those for pure substances and by removing certain constituents from the vapour with the help of chemical reagents. To simplify the analyses, the first tests were carried out on concentrated apple juice from which the volatile substances had been removed before irradiation. Irradiation gave rise to five aldehydes in the normal apple juice (acetaldehyde, isobutyraldehyde, butyraldehyde, isovaldehyde and capronaldehyde), but only three in the concentrated juice (acetaldehyde, isobutyraldehyde and isovaleraldehyde). In addition, 2-butanone appeared in the concentrated juice; however, the peak corresponding to it on the chromatogram was completely masked by the ethanol peak in the case of non-concentrated juice. Furan was also detected, together with traces of two compounds that have not yet been identified. Similar results have been obtained by pasteurization, such as in bottling by heat. (author)

  17. Relationships between functional genes in Lactobacillus delbrueckii ssp. bulgaricus isolates and phenotypic characteristics associated with fermentation time and flavor production in yogurt elucidated using multilocus sequence typing.

    Science.gov (United States)

    Liu, Wenjun; Yu, Jie; Sun, Zhihong; Song, Yuqin; Wang, Xueni; Wang, Hongmei; Wuren, Tuoya; Zha, Musu; Menghe, Bilige; Heping, Zhang

    2016-01-01

    Lactobacillus delbrueckii ssp. bulgaricus (L. bulgaricus) is well known for its worldwide application in yogurt production. Flavor production and acid producing are considered as the most important characteristics for starter culture screening. To our knowledge this is the first study applying functional gene sequence multilocus sequence typing technology to predict the fermentation and flavor-producing characteristics of yogurt-producing bacteria. In the present study, phenotypic characteristics of 35 L. bulgaricus strains were quantified during the fermentation of milk to yogurt and during its subsequent storage; these included fermentation time, acidification rate, pH, titratable acidity, and flavor characteristics (acetaldehyde concentration). Furthermore, multilocus sequence typing analysis of 7 functional genes associated with fermentation time, acid production, and flavor formation was done to elucidate the phylogeny and genetic evolution of the same L. bulgaricus isolates. The results showed that strains significantly differed in fermentation time, acidification rate, and acetaldehyde production. Combining functional gene sequence analysis with phenotypic characteristics demonstrated that groups of strains established using genotype data were consistent with groups identified based on their phenotypic traits. This study has established an efficient and rapid molecular genotyping method to identify strains with good fermentation traits; this has the potential to replace time-consuming conventional methods based on direct measurement of phenotypic traits.

  18. Efficient photocatalytic degradation of organics present in gas and liquid phases using Pt-TiO2/Zeolite (H-ZSM).

    Science.gov (United States)

    Neppolian, B; Mine, Shinya; Horiuchi, Yu; Bianchi, C L; Matsuoka, M; Dionysiou, D D; Anpo, M

    2016-06-01

    TiO2-encapsulated H-ZSM photocatalysts were prepared by physical mixing of TiO2 and zeolites. Pt was immobilized on the surface of the TiO2-encapsulated zeolite (H-ZSM) catalysts by a simple photochemical reduction method. Different weight ratios of both TiO2 and Pt were hybridized with H-ZSM and the catalytic performance of the prepared catalysts was investigated for 2-propanol oxidation in liquid phase and acetaldehyde in gas phase reaction. Around 5-10 wt% TiO2-encapsulated H-ZSM catalysts was found to be optimal amount for the effective oxidation of the organics. Prior to light irradiation, Pt-TiO2-H-ZSM showed considerable amount of catalytic degradation of 2-propanol in the dark, forming acetone as an intermediate. In this study, Pt has played a major and important role on the total oxidation of 2-propanol as well as acetaldehyde. As a result, no residual organics were present in the pores of the zeolites. The catalysts could be reused more than three times without losing their catalytic activity in both phases. The Pt-TiO2-H-ZSM photocatalysts could overcome the problem of strong adsorption of organics in the zeolite pores (after the reaction). Thus, Pt-TiO2-H-ZSM can be used as a potential catalyst for both liquid and gas phase oxidation of organic pollutants.

  19. Influence of ethanol-gasoline blended fuel on emission characteristics from a four-stroke motorcycle engine.

    Science.gov (United States)

    Jia, Li-Wei; Shen, Mei-Qing; Wang, Jun; Lin, Man-Qun

    2005-08-31

    Emission characteristics from a four-stroke motorcycle engine using 10% (v/v) ethanol-gasoline blended fuel (E10) were investigated at different driving modes on the chassis dynamometers. The results indicate that CO and HC emissions in the engine exhaust are lower with the operation of E10 as compared to the use of unleaded gasoline, whereas the effect of ethanol on NO(X) emission is not significant. Furthermore, species of both unburned hydrocarbons and their ramifications were analyzed by the combination of gas chromatography/mass spectrometry (GC/MS) and gas chromatography/flame ionization detection (GC/FID). This analysis shows that aromatic compounds (benzene, toluene, xylene isomers (o-xylene, m-xylene and p-xylene), ethyltoluene isomers (o-ethyltoluene, m-ethyltoluene and p-ethyltoluene) and trimethylbenzene isomers (1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene and 1,3,5-trimethylbenzene)) and fatty group ones (ethylene, methane, acetaldehyde, ethanol, butene, pentane and hexane) are major compounds in motorcycle engine exhaust. It is found that the E10-fueled motorcycle engine produces more ethylene, acetaldehyde and ethanol emissions than unleaded gasoline engine does. The no significant reduction of aromatics is observed in the case of ethanol-gasoline blended fuel. The ethanol-gasoline blended fuel can somewhat improve emissions of the rest species.

  20. [Preparation of ethanol-diesel fuel blends and exhausts emission characteristics in diesel engine].

    Science.gov (United States)

    Zhang, Runduo; He, Hong; Zhang, Changbin; Shi, Xiaoyan

    2003-07-01

    The technology that diesel oil is partly substituted by ethanol can reduce diesel engine exhausts emission, especially fuel soot. This research is concentrated on preparation of ethanol-diesel blend fuel and exhausts emission characteristics using diesel engine bench. Absolute ethanol can dissolve into diesel fuel at an arbitrary ratio. However, a trace of water (0.2%) addition can lead to the phase separation of blends. Organic additive synthesized during this research can develop the ability of resistance to water and maintain the stability of ethanol-diesel-trace amounts of water system. The effects of 10%, 20%, and 30% ethanol-diesel fuel blends on exhausts emission, were compared with that of diesel fuel in direct injection (DI) diesel engine. The optimum ethanol percentage for ethanol-diesel fuel blends was 20%. Using 20% ethanol-diesel fuel blend with 2% additive of the total volume, bench diesel engine showed a large amount decrease of exhaust gas, e.g. 55% of Bosch smoke number, 70% of HC emission, and 45% of CO emission at 13 kW and 1540 r/min. Without the addition of additive, the blend of ethanol produced new organic compounds such as ethanol and acetaldehyde in tail gas. However, the addition of additive obviously reduced the emission of ethanol and acetaldehyde.

  1. Acetylene as fast food: Implications for development of life on anoxic primordial earth and in the outer solar system

    Science.gov (United States)

    Oremland, R.S.; Voytek, M.A.

    2008-01-01

    Acetylene occurs, by photolysis of methane, in the atmospheres of jovian planets and Titan. In contrast, acetylene is only a trace component of Earth's current atmosphere. Nonetheless, a methane-rich atmosphere has been hypothesized for early Earth; this atmosphere would also have been rich in acetylene. This poses a paradox, because acetylene is a potent inhibitor of many key anaerobic microbial processes, including methanogenesis, anaerobic methane oxidation, nitrogen fixation, and hydrogen oxidation. Fermentation of acetylene was discovered 25 years ago, and Pelobacter acetylenicus was shown to grow on acetylene by virtue of acetylene hydratase, which results in the formation of acetaldehyde. Acetaldehyde subsequently dismutates to ethanol and acetate (plus some hydrogen). However, acetylene hydratase is specific for acetylene and does not react with any analogous compounds. We hypothesize that microbes with acetylene hydratase played a key role in the evolution of Earth's early biosphere by exploiting an available source of carbon from the atmosphere and in so doing formed protective niches that allowed for other microbial processes to flourish. Furthermore, the presence of acetylene in the atmosphere of a planet or planetoid could possibly represent evidence for an extraterrestrial anaerobic ecosystem. ?? Mary Ann Liebert, Inc.

  2. Photoinduced catalytic synthesis of biologically important metabolites from formaldehyde and ammonia under plausible "prebiotic" conditions

    Science.gov (United States)

    Delidovich, I. V.; Taran, O. P.; Simonov, A. N.; Matvienko, L. G.; Parmon, V. N.

    2011-08-01

    The article analyzes new and previously reported data on several catalytic and photochemical processes yielding biologically important molecules. UV-irradiation of formaldehyde aqueous solution yields acetaldehyde, glyoxal, glycolaldehyde and glyceraldehyde, which can serve as precursors of more complex biochemically relevant compounds. Photolysis of aqueous solution of acetaldehyde and ammonium nitrate results in formation of alanine and pyruvic acid. Dehydration of glyceraldehyde catalyzed by zeolite HZSM-5-17 yields pyruvaldehyde. Monosaccharides are formed in the course of the phosphate-catalyzed aldol condensation reactions of glycolaldehyde, glyceraldehyde and formaldehyde. The possibility of the direct synthesis of tetroses, keto- and aldo-pentoses from pure formaldehyde due to the combination of the photochemical production of glycolahyde and phosphate-catalyzed carbohydrate chain growth is demonstrated. Erythrulose and 3-pentulose are the main products of such combined synthesis with selectivity up to 10%. Biologically relevant aldotetroses, aldo- and ketopentoses are more resistant to the photochemical destruction owing to the stabilization in hemiacetal cyclic forms. They are formed as products of isomerization of erythrulose and 3-pentulose. The conjugation of the concerned reactions results in a plausible route to the formation of sugars, amino and organic acids from formaldehyde and ammonia under presumed 'prebiotic' conditions.

  3. Proteins involved in wine aroma compounds metabolism by a Saccharomyces cerevisiae flor-velum yeast strain grown in two conditions.

    Science.gov (United States)

    Moreno-García, Jaime; García-Martínez, Teresa; Millán, M Carmen; Mauricio, Juan Carlos; Moreno, Juan

    2015-10-01

    A proteomic and exometabolomic study was conducted on Saccharomyces cerevisiae flor yeast strain growing under biofilm formation condition (BFC) with ethanol and glycerol as carbon sources and results were compared with those obtained under no biofilm formation condition (NBFC) containing glucose as carbon source. By using modern techniques, OFFGEL fractionator and LTQ-Orbitrap for proteome and SBSE-TD-GC-MS for metabolite analysis, we quantified 84 proteins including 33 directly involved in the metabolism of glycerol, ethanol and 17 aroma compounds. Contents in acetaldehyde, acetic acid, decanoic acid, 1,1-diethoxyethane, benzaldehyde and 2-phenethyl acetate, changed above their odor thresholds under BFC, and those of decanoic acid, ethyl octanoate, ethyl decanoate and isoamyl acetate under NBFC. Of the twenty proteins involved in the metabolism of ethanol, acetaldehyde, acetoin, 2,3-butanediol, 1,1-diethoxyethane, benzaldehyde, organic acids and ethyl esters, only Adh2p, Ald4p, Cys4p, Fas3p, Met2p and Plb1p were detected under BFC and as many Acs2p, Ald3p, Cem1p, Ilv2p, Ilv6p and Pox1p, only under NBFC. Of the eight proteins involved in glycerol metabolism, Gut2p was detected only under BFC while Pgs1p and Rhr2p were under NBFC. Finally, of the five proteins involved in the metabolism of higher alcohols, Thi3p was present under BFC, and Aro8p and Bat2p were under NBFC. PMID:26187821

  4. Molecular and biochemical characterization of bifunctional pyruvate decarboxylases and pyruvate ferredoxin oxidoreductases from Thermotoga maritima and Thermotoga hypogea.

    Science.gov (United States)

    Eram, Mohammad S; Wong, Alton; Oduaran, Erica; Ma, Kesen

    2015-12-01

    Hyperthermophilic bacteria Thermotoga maritima and Thermotoga hypogea produce ethanol as a metabolic end product, which is resulted from acetaldehyde reduction catalysed by an alcohol dehydrogenase (ADH). However, the enzyme that is involved in the production of acetaldehyde from pyruvate is not well characterized. An oxygen sensitive and coenzyme A-dependent pyruvate decarboxylase (PDC) activity was found to be present in cell free extracts of T. maritima and T. hypogea. Both enzymes were purified and found to have pyruvate ferredoxin oxidoreductase (POR) activity, indicating their bifunctionality. Both PDC and POR activities from each of the purified enzymes were characterized in regards to their optimal assay conditions including pH dependency, oxygen sensitivity, thermal stability, temperature dependency and kinetic parameters. The close relatedness of the PORs that was shown by sequence analysis could be an indication of the presence of such bifunctionality in other hyperthermophilic bacteria. This is the first report of a bifunctional PDC/POR enzyme in hyperthermophilic bacteria. The PDC and the previously reported ADHs are most likely the key enzymes catalysing the production of ethanol from pyruvate in bacterial hyperthermophiles.

  5. Proteins involved in wine aroma compounds metabolism by a Saccharomyces cerevisiae flor-velum yeast strain grown in two conditions.

    Science.gov (United States)

    Moreno-García, Jaime; García-Martínez, Teresa; Millán, M Carmen; Mauricio, Juan Carlos; Moreno, Juan

    2015-10-01

    A proteomic and exometabolomic study was conducted on Saccharomyces cerevisiae flor yeast strain growing under biofilm formation condition (BFC) with ethanol and glycerol as carbon sources and results were compared with those obtained under no biofilm formation condition (NBFC) containing glucose as carbon source. By using modern techniques, OFFGEL fractionator and LTQ-Orbitrap for proteome and SBSE-TD-GC-MS for metabolite analysis, we quantified 84 proteins including 33 directly involved in the metabolism of glycerol, ethanol and 17 aroma compounds. Contents in acetaldehyde, acetic acid, decanoic acid, 1,1-diethoxyethane, benzaldehyde and 2-phenethyl acetate, changed above their odor thresholds under BFC, and those of decanoic acid, ethyl octanoate, ethyl decanoate and isoamyl acetate under NBFC. Of the twenty proteins involved in the metabolism of ethanol, acetaldehyde, acetoin, 2,3-butanediol, 1,1-diethoxyethane, benzaldehyde, organic acids and ethyl esters, only Adh2p, Ald4p, Cys4p, Fas3p, Met2p and Plb1p were detected under BFC and as many Acs2p, Ald3p, Cem1p, Ilv2p, Ilv6p and Pox1p, only under NBFC. Of the eight proteins involved in glycerol metabolism, Gut2p was detected only under BFC while Pgs1p and Rhr2p were under NBFC. Finally, of the five proteins involved in the metabolism of higher alcohols, Thi3p was present under BFC, and Aro8p and Bat2p were under NBFC.

  6. FTIR-ATR spectroscopy applied to quality control of grape-derived spirits.

    Science.gov (United States)

    Anjos, Ofélia; Santos, António J A; Estevinho, Letícia M; Caldeira, Ilda

    2016-08-15

    The Fourier transform infrared (FTIR) spectroscopic method with attenuated total reflectance (ATR) was used for predicting the alcoholic strength, the methanol, acetaldehyde and fusel alcohols content of grape-derived spirits. FTIR-ATR spectrum in the mid-IR region (4000-400cm(-1)) was used for the quantitative estimation by applying partial least square (PLS) regression models and the results were correlated with those obtained from reference methods. In the developed method, a cross-validation with 50% of the samples was used for PLS analysis along with a validation test set with 50% of the remaining samples. Good correlation models with a great accuracy were obtained for methanol (r(2)=99.4; RPD=12.8), alcoholic strength (r(2)=97.2; RPD=6.0), acetaldehyde (r(2)=98.2; RPD=7.5) and fusel alcohols (r(2) from 97.4 to 94.1; RPD from 6.2 to 4.1). These results corroborate the hypothesis that FTIR-ATR is a useful technique for the quality control of grape-derived spirits, whose practical application may improve the efficiency and quickness of the current laboratory analysis. PMID:27006210

  7. Isolation and expression of NAC genes during persimmon fruit postharvest astringency removal.

    Science.gov (United States)

    Min, Ting; Wang, Miao-Miao; Wang, Hongxun; Liu, Xiaofen; Fang, Fang; Grierson, Donald; Yin, Xue-Ren; Chen, Kun-Song

    2015-01-01

    NAC genes have been characterized in numerous plants, where they are involved in responses to biotic and abiotic stress, including low oxygen stress. High concentration of CO2 is one of the most effective treatments to remove astringency of persimmon fruit owing to the action of the accumulated anoxia metabolite acetaldehyde. In model plants, NAC genes have been identified as being responsive to low oxygen. However, the possible relationship between NAC transcription factors and persimmon astringency removal remains unexplored. In the present research, treatment with a high concentration of CO2 (95%) effectively removed astringency of "Mopan" persimmon fruit by causing decreases in soluble tannin. Acetaldehyde content increased in response to CO2 treatment concomitantly with astringency removal. Using RNA-seq and Rapid amplification of cDNA ends (RACE), six DkNAC genes were isolated and studied. Transcriptional analysis indicated DkNAC genes responded differentially to CO2 treatment; DkNAC1, DkNAC3, DkNAC5 and DkNAC6 were transiently up-regulated, DkNAC2 was abundantly expressed 3 days after treatment, while the DkNAC4 was suppressed during astringency removal. It is proposed that DkNAC1/3/5/6 could be important candidates as regulators of persimmon astringency removal and the roles of other member are also discussed. PMID:25599529

  8. Effects of 20 Selected Fruits on Ethanol Metabolism: Potential Health Benefits and Harmful Impacts.

    Science.gov (United States)

    Zhang, Yu-Jie; Wang, Fang; Zhou, Yue; Li, Ya; Zhou, Tong; Zheng, Jie; Zhang, Jiao-Jiao; Li, Sha; Xu, Dong-Ping; Li, Hua-Bin

    2016-04-01

    The consumption of alcohol is often accompanied by other foods, such as fruits and vegetables. This study is aimed to investigate the effects of 20 selected fruits on ethanol metabolism to find out their potential health benefits and harmful impacts. The effects of the fruits on ethanol metabolism were characterized by the concentrations of ethanol and acetaldehyde in blood, as well as activities of alcohol dehydrogenase and acetaldehyde dehydrogenase in liver of mice. Furthermore, potential health benefits and harmful impacts of the fruits were evaluated by biochemical parameters including aspartate transaminase (AST), alanine transferase (ALT), malondialdehyde, and superoxide dismutase. Generally, effects of these fruits on ethanol metabolism were very different. Some fruits (such as Citrus limon (yellow), Averrhoa carambola, Pyrus spp., and Syzygium samarangense) could decrease the concentration of ethanol in blood. In addition, several fruits (such as Cucumis melo) showed hepatoprotective effects by significantly decreasing AST or ALT level in blood, while some fruits (such as Averrhoa carambola) showed adverse effects. The results suggested that the consumption of alcohol should not be accompanied by some fruits, and several fruits could be developed as functional foods for the prevention and treatment of hangover and alcohol use disorder.

  9. The roles of aldehyde dehydrogenases (ALDHs in the PDH bypass of Arabidopsis

    Directory of Open Access Journals (Sweden)

    Lin Ming

    2009-03-01

    Full Text Available Abstract Background Eukaryotic aldehyde dehydrogenases (ALDHs, EC 1.2.1, which oxidize aldehydes into carboxylic acids, have been classified into more than 20 families. In mammals, Family 2 ALDHs detoxify acetaldehyde. It has been hypothesized that plant Family 2 ALDHs oxidize acetaldehyde generated via ethanolic fermentation, producing acetate for acetyl-CoA biosynthesis via acetyl-CoA synthetase (ACS, similar to the yeast pathway termed the "pyruvate dehydrogenase (PDH bypass". Evidence for this pathway in plants has been obtained from pollen. Results To test for the presence of the PDH bypass in the sporophytic tissue of plants, Arabidopsis plants homozygous for mutant alleles of all three Family 2 ALDH genes were fed with 14C-ethanol along with wild type controls. Comparisons of the incorporation rates of 14C-ethanol into fatty acids in mutants and wild type controls provided direct evidence for the presence of the PDH bypass in sporophytic tissue. Among the three Family 2 ALDHs, one of the two mitochondrial ALDHs (ALDH2B4 appears to be the primary contributor to this pathway. Surprisingly, single, double and triple ALDH mutants of Arabidopsis did not exhibit detectable phenotypes, even though a Family 2 ALDH gene is required for normal anther development in maize. Conclusion The PDH bypass is active in sporophytic tissue of plants. Blocking this pathway via triple ALDH mutants does not uncover obvious visible phenotypes.

  10. Pollution survey of carbonyl compounds in train air

    Institute of Scientific and Technical Information of China (English)

    LU Hao; ZHU Lizhong

    2007-01-01

    The train iS an important vehicle in China,but its air quality has important impacts on passengers' health.In this work,pollution from carbonyl compounds was measured in the air of six trains.The obiectives of this work were to investigate carbonyl compound levels in selected air from trains,identify their emission sources,and assess the intake of carbonyl compounds for passengers.The methods for sampling and analyzing 10 carbonyl compounds such as formaldehyde,acetaldehyde,acrolein,acetone,propionalde hyde,crotonaldehyde,butyraldehyde,benzaldehyde,cyclo hexanone,and valeraldehyde in indoor air were proposed with the sampling efficiency,recovery,and detection limit being 92%-100%,91%-104%,and 0.26-0.82 ng/m3,respec tively.It was indicated that the total concentrations of carbonyl compounds were 0.159-0.2828 mg/m3 with the average concentration of 0.2330 mg/m3.The average concen trations of formaldehyde.acetaldehyde and acetone were 0.0922,0.0499,and 0.0580 mg/m3,accounting for 42.6%,21.4%.and 24.9% of the total concentrations of carbonyl compounds,respectively.The carbonyl compounds probably came from woodwork and cigarette smoking.The intake of carbonyl compounds for the passengers was approximately 0.043-0.076 mg/h.The carbonyl compounds in train air could be harmful to human health.

  11. The Products of the Thermal Decomposition of CH3CHO

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliou, AnGayle; Piech, Krzysztof M.; Zhang, Xu; Nimlos, Mark R.; Ahmed, Musahid; Golan, Amir; Kostko, Oleg; Osborn, David L.; Daily, John W.; Stanton, John F.; Ellison, G. Barney

    2011-04-06

    We have used a heated 2 cm x 1 mm SiC microtubular (mu tubular) reactor to decompose acetaldehyde: CH3CHO + DELTA --> products. Thermal decomposition is followed at pressures of 75 - 150 Torr and at temperatures up to 1700 K, conditions that correspond to residence times of roughly 50 - 100 mu sec in the mu tubular reactor. The acetaldehyde decomposition products are identified by two independent techniques: VUV photoionization mass spectroscopy (PIMS) and infrared (IR) absorption spectroscopy after isolation in a cryogenic matrix. Besides CH3CHO, we have studied three isotopologues, CH3CDO, CD3CHO, and CD3CDO. We have identified the thermal decomposition products CH3(PIMS), CO (IR, PIMS), H (PIMS), H2 (PIMS), CH2CO (IR, PIMS), CH2=CHOH (IR, PIMS), H2O (IR, PIMS), and HC=CH (IR, PIMS). Plausible evidence has been found to support the idea that there are at least three different thermal decomposition pathways for CH3CHO: Radical decomposition: CH3CHO + DELTA --> CH3 + [HCO] --> CH3 + H + CO Elimination: CH3CHO + DELTA --> H2 + CH2=C=O. Isomerization/elimination: CH3CHO + DELTA --> [CH2=CH-OH] --> HC=CH + H2O. Both PIMS and IR spectroscopy show compelling evidence for the participation of vinylidene, CH2=C:, as an intermediate in the decomposition of vinyl alchohol: CH2=CH-OH + DELTA --> [CH2=C:] + H2O --> HC=CH + H2O.

  12. Measurement of n-alkanals and hydroxyalkenals in biological samples.

    Science.gov (United States)

    Holley, A E; Walker, M K; Cheeseman, K H; Slater, T F

    1993-09-01

    A modified method was developed to measure nM levels of a range of n-alkanals and hydroxyalkenals in biological samples such as blood plasma and tissue homogenates and also in Folch lipid extracts of these samples. Butylated hydroxytoluene (BHT) and desferrioxamine (Desferal) were added to samples to prevent artifactual peroxidation. Aldehydes were reacted with 1,3-cyclohexanedione (CHD), cleaned up by solid-phase extraction on a Sep-Pak C18 cartridge and the fluorescent decahydroacridine derivatives resolved by reverse-phase high-performance liquid chromatography (HPLC) with gradient elution. A wider range of aldehydes was detected in lipid extracts of plasma and liver homogenate compared to whole (unextracted) samples. Human plasma contained nM levels of acetaldehyde, propanal, butanal, pentanal, hexanal, and heptanal. 4-Hydroxynonenal (0.93 nmol/g) and alkanals with two to six carbons (up to 7.36 nmol/g) were detected in rat liver. Recovery of aldehydes added to whole plasma or to lipid extracts of plasma was dependent on carbon chain length, varying from 95% for acetaldehyde to 8% for decanal. Recovery from biological samples was significantly less than that of standards taken through the Sep-Pak clean-up procedure, suggesting that aldehydes can bind to plasma protein and lipid components. PMID:8406128

  13. [Chemical Characteristics and Sources of Atmospheric Carbonyls During the 2014 Beijing APEC].

    Science.gov (United States)

    He, Xiao-lang; Tan, Ji-hua; Guo, Song-jun; Ma, Yong-liang; He, Ke-bin

    2016-03-15

    Pollution characteristic and variation trend of atmospheric carbonyls were investigated in November during the 2014 Beijing APEC. Formaldehyde, acetaldehyde and acetone were the dominant carbonyls, accounting for 82.66% of total carbonyls, and especially, formaldehyde accounted for 40.12% of total carbonyls. Atmospheric concentrations of total carbonyls decreased by around 64.10% after the clean air policy was carried out during the Beijing APEC, and the variation trend of carbonyls showed a similar pattern to those of other pollutants like PM₂.₅ during the APEC. Strong correlations (R² of 0.67-0.98) were observed among formaldehyde, acetaldehyde, acetone and total carbonyls during and after the APEC, indicating that they had similar sources; however, poor correlations (R² of -0.11-0.42 and 0.16-0.94, respectively) were observed before the APEC, implying different emission sources for ambient carbonyls. The calculated ratios of C1/C2, C2/C3 and OC/EC indicated that both vehicles and coal emissions were responsible for atmospheric carbonyls before the APEC, and emissions from coal burning were the major contributor to atmospheric carbonyls during and after the APEC, especially after the APEC. PMID:27337869

  14. Results of the California Healthy Homes Indoor Air Quality Study of 2011-2013: impact of natural gas appliances on air pollutant concentrations.

    Science.gov (United States)

    Mullen, N A; Li, J; Russell, M L; Spears, M; Less, B D; Singer, B C

    2016-04-01

    This study was conducted to assess the current impact of natural gas appliances on air quality in California homes. Data were collected via telephone interviews and measurements inside and outside of 352 homes. Passive samplers measured time-resolved CO and time-integrated NOX , NO2 , formaldehyde, and acetaldehyde over ~6-day periods in November 2011 - April 2012 and October 2012 - March 2013. The fraction of indoor NOX and NO2 attributable to indoor sources was estimated. NOX , NO2 , and highest 1-h CO were higher in homes that cooked with gas and increased with amount of gas cooking. NOX and NO2 were higher in homes with cooktop pilot burners, relative to gas cooking without pilots. Homes with a pilot burner on a floor or wall furnace had higher kitchen and bedroom NOX and NO2 compared to homes without a furnace pilot. When scaled to account for varying home size and mixing volume, indoor-attributed bedroom and kitchen NOX and kitchen NO2 were not higher in homes with wall or floor furnace pilot burners, although bedroom NO2 was higher. In homes that cooked 4 h or more with gas, self-reported use of kitchen exhaust was associated with lower NOX , NO2 , and highest 1-h CO. Gas appliances were not associated with higher concentrations of formaldehyde or acetaldehyde.

  15. Non-Catalytic and MgSO4 - Catalyst based Degradation of Glycerol in Subcritical and Supercritical Water Media

    Directory of Open Access Journals (Sweden)

    Mahfud Mahfud

    2011-02-01

    Full Text Available This research aims to study the glycerol degradation reaction in subcritical and supercritical water media. The degradation of glycerol into other products was performed both with sulphate salt catalysts and without catalyst. The reactant was made from glycerol and water with the mass ratio of 1:10. The experiments were carried out using a batch reactor at a constant pressure of 250 kgf/cm2, with the temperature range of 200-400oC, reaction time of 30 minutes, and catalyst mol ratio in glycerol of 1:10 and 1:8. The products of the non-catalytic glycerol degradation were acetaldehyde, methanol, and ethanol. The use of sulphate salt as catalyst has high selectivity to acetaldehyde and still allows the formation alcohol product in small quantities. The mechanism of ionic reaction and free radical reaction can occur at lower temperature in hydrothermal area or subcritical water. Conversion of glycerol on catalytic reaction showed a higher yield when compared with the reaction performed without catalyst

  16. Virtual disjunct eddy covariance measurements of organic compound fluxes from a subalpine forest using proton transfer reaction mass spectrometry

    Directory of Open Access Journals (Sweden)

    T. G. Karl

    2002-07-01

    Full Text Available A `virtual' disjunct eddy covariance (vDEC device was tested with field measurements of biogenic VOC fluxes at a subalpine forest site in the Rocky Mountains of the U.S.A. A PTR-MS instrument was used as the VOC sensor. Daily peak emission fluxes of 2-methyl-3-buten-2-ol (MBO, methanol, acetone and acetaldehyde were around 1.5, 1, 0.8 and 0.4 mg m-2 h-1, respectively. High pass filtering due to long sampling lines was investigated in laboratory experiments, and suggested that VOC losses in PTFA lines are generally governed by diffusion laws. Memory effects and surface reactions did not seem to play a dominant role. Model estimates of MBO fluxes compared well with measured fluxes. The results also suggest that latent heat and sensible heat fluxes are reasonably well correlated with VOC fluxes and could be used to predict variations in VOC emissions. The release of MBO, methanol, acetone and acetaldehyde resulted in significant change of tropospheric oxidant levels and a 10--40% increase in ozone levels, as inferred from a photochemical box model. We conclude that vDEC with a PTR-MS instrument is a versatile tool for simultaneous field analysis of multiple VOC fluxes.

  17. TiO2-Impregnated Porous Silica Tube and Its Application for Compact Air- and Water-Purification Units

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Ochiai

    2015-09-01

    Full Text Available A simple, convenient, reusable, and inexpensive air- and water-purification unit including a one-end sealed porous amorphous-silica (a-silica tube coated with TiO2 photocatalyst layers has been developed. The porous a-silica layers were formed through outside vapor deposition (OVD. TiO2 photocatalyst layers were formed through impregnation and calcination onto a-silica layers. The resulting porous TiO2-impregnated a-silica tubes were evaluated for air-purification capacity using an acetaldehyde gas decomposition test. The tube (8.5 mm e.d. × 150 mm demonstrated a 93% removal rate for high concentrations (ca. 300 ppm of acetaldehyde gas at a single-pass condition with a 250 mL/min flow rate under UV irradiation. The tube also demonstrated a water purification capacity at a rate 2.0 times higher than a-silica tube without TiO2 impregnation. Therefore, the tubes have a great potential for developing compact and in-line VOC removal and water-purification units.

  18. The oxidative fermentation of ethanol in Gluconacetobacter diazotrophicus is a two-step pathway catalyzed by a single enzyme: alcohol-aldehyde Dehydrogenase (ADHa).

    Science.gov (United States)

    Gómez-Manzo, Saúl; Escamilla, José E; González-Valdez, Abigail; López-Velázquez, Gabriel; Vanoye-Carlo, América; Marcial-Quino, Jaime; de la Mora-de la Mora, Ignacio; Garcia-Torres, Itzhel; Enríquez-Flores, Sergio; Contreras-Zentella, Martha Lucinda; Arreguín-Espinosa, Roberto; Kroneck, Peter M H; Sosa-Torres, Martha Elena

    2015-01-01

    Gluconacetobacter diazotrophicus is a N2-fixing bacterium endophyte from sugar cane. The oxidation of ethanol to acetic acid of this organism takes place in the periplasmic space, and this reaction is catalyzed by two membrane-bound enzymes complexes: the alcohol dehydrogenase (ADH) and the aldehyde dehydrogenase (ALDH). We present strong evidence showing that the well-known membrane-bound Alcohol dehydrogenase (ADHa) of Ga. diazotrophicus is indeed a double function enzyme, which is able to use primary alcohols (C2-C6) and its respective aldehydes as alternate substrates. Moreover, the enzyme utilizes ethanol as a substrate in a reaction mechanism where this is subjected to a two-step oxidation process to produce acetic acid without releasing the acetaldehyde intermediary to the media. Moreover, we propose a mechanism that, under physiological conditions, might permit a massive conversion of ethanol to acetic acid, as usually occurs in the acetic acid bacteria, but without the transient accumulation of the highly toxic acetaldehyde. PMID:25574602

  19. Photocatalytic Ethanol Oxidative Dehydrogenation over Pt/TiO2: Effect of the Addition of Blue Phosphors

    Directory of Open Access Journals (Sweden)

    J. J. Murcia

    2012-01-01

    Full Text Available Ethanol oxidative dehydrogenation over Pt/TiO2 photocatalyst, in the presence and absence of blue phosphors, was performed. The catalyst was prepared by photodeposition of Pt on sulphated TiO2. This material was tested in a gas-solid photocatalytic fluidized bed reactor at high illumination efficiency. The effect of the addition of blue phosphors into the fluidized bed has been evaluated. The synthesized catalysts were extensively characterized by different techniques. Pt/TiO2 with a loading of 0.5 wt% of Pt appeared to be an active photocatalyst in the selective partial oxidation of ethanol to acetaldehyde improving its activity and selectivity compared to pure TiO2. In the same way, a notable enhancement of ethanol conversion in the presence of the blue phosphors has been obtained. The blue phosphors produced an increase in the level of ethanol conversion over the Pt/TiO2 catalyst, keeping at the same time the high selectivity to acetaldehyde.

  20. Efeito da presença e concentração de compostos carbonílicos na qualidade de vinhos Effects of carbonylic compound presence and concentration on wine quality

    Directory of Open Access Journals (Sweden)

    Luciana C. de Azevêdo

    2007-01-01

    Full Text Available Studies on identification of compounds that make up the aroma and flavor in wines involve research evaluating mainly the influence of terpenes, esters, lactones and alcohols upon these sensory characteristics. However, carbonylic compounds (CC play an important role concerning the substances that impact aroma to these drinks. Their origin is reported to be linked to the grape's chemical composition, must fermentation or micro-oxidation occurring during storage in barrels. Some CCs, like E-ionone, E-damascenone, siryngaldehyde, can contribute a pleasant aroma and improve the wine quality whereas others are responsible for unpleasant characteristics (acetaldehyde, furfural, 5-hydroxy-methyl furfural, diacetil, E-non-2-enal, etc. A fraction of CCs present is associated with bisulfite ions in the form of hydroxyalkylsulfonic acids. Some of them are stable and play an important role in determining wine quality. The reaction involving the formation of this aduct commonly occurs with CCs of low molar mass, such as formaldehyde and acetaldehyde. The reaction involving CCs with more than three carbon atoms demands further studies.

  1. Safety Evaluation of the Grape Marc Spirit by GC-FID Analysis

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    Teodora Coldea

    2013-11-01

    Full Text Available There were investigated grape marc spirits regarding their safety on consumers. Major volatile compounds which present risk to human health (such as methanol, furfural, and acetaldehyde and ethyl alcohol content were compared to European Union Regulation and other values found in previous studies.  The aim of our study was to evaluate the safety of grape marc spirits considering their content in major volatile compounds by comparison with the requirements of European Union Regulation. We investigated the ethyl alcohol content by electronic densimetry and 10 major volatile compounds (acetaldehyde, ethyl acetate, methanol, 1-propanol, 1-butanol, 2-butanol, isobutyl alcohol, isoamyl alcohol, amyl active alcohol and furfural by Gas Chromatography coupled with Flame Ionization Detector. We used reference chemicals to identify these compounds and 3-pentanol as internal standard to quantify the volatiles. Results were compared with the requirements of European Union Regulation. All major volatile compounds registered values in accordance to EU Regulation and the grape pomace spirits samples do not present any kind of risk for consumption.

  2. Virtual disjunct eddy covariance measurements of organic compound fluxes from a subalpine forest using proton transfer reaction mass spectrometry

    Directory of Open Access Journals (Sweden)

    T. G. Karl

    2002-01-01

    Full Text Available A `virtual' disjunct eddy covariance (vDEC device was tested with field measurements of biogenic VOC fluxes at a subalpine forest site in the Rocky Mountains of the USA. A PTR-MS instrument was used as the VOC sensor. Daily peak emission fluxes of 2-methyl-3-buten-2-ol (MBO, methanol, acetone and acetaldehyde were around 1.5, 1, 0.8 and 0.4 mg m-2 h-1, respectively. High pass filtering due to long sampling lines was investigated in laboratory experiments, and suggested that VOC losses in PTFA lines are generally governed by diffusion laws. Memory effects and surface reactions did not seem to play a dominant role. Model estimates of MBO fluxes compared well with measured fluxes. The results also suggest that latent heat and sensible heat fluxes are reasonably well correlated with VOC fluxes and could be used to predict variations in VOC emissions. The release of MBO, methanol, acetone and acetaldehyde resulted in significant change of tropospheric oxidant levels and a 10--40% increase in ozone levels, as inferred from a photochemical box model. We conclude that vDEC with a PTR-MS instrument is a versatile tool for simultaneous field analysis of multiple VOC fluxes.

  3. Acetate causes alcohol hangover headache in rats.

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    Christina R Maxwell

    Full Text Available BACKGROUND: The mechanism of veisalgia cephalgia or hangover headache is unknown. Despite a lack of mechanistic studies, there are a number of theories positing congeners, dehydration, or the ethanol metabolite acetaldehyde as causes of hangover headache. METHODS: We used a chronic headache model to examine how pure ethanol produces increased sensitivity for nociceptive behaviors in normally hydrated rats. RESULTS: Ethanol initially decreased sensitivity to mechanical stimuli on the face (analgesia, followed 4 to 6 hours later by inflammatory pain. Inhibiting alcohol dehydrogenase extended the analgesia whereas inhibiting aldehyde dehydrogenase decreased analgesia. Neither treatment had nociceptive effects. Direct administration of acetate increased nociceptive behaviors suggesting that acetate, not acetaldehyde, accumulation results in hangover-like hypersensitivity in our model. Since adenosine accumulation is a result of acetate formation, we administered an adenosine antagonist that blocked hypersensitivity. DISCUSSION: Our study shows that acetate contributes to hangover headache. These findings provide insight into the mechanism of hangover headache and the mechanism of headache induction.

  4. Ginsenoside-free molecules from steam-dried ginseng berry promote ethanol metabolism: an alternative choice for an alcohol hangover.

    Science.gov (United States)

    Lee, Do Ik; Kim, Seung Tae; Lee, Dong Hoon; Yu, Jung Min; Jang, Su Kil; Joo, Seong Soo

    2014-07-01

    Ethanol metabolism produces harmful compounds that contribute to liver damage and cause an alcohol hangover. The intermediate metabolite acetaldehyde is responsible for alcohol hangover and CYP2E1-induced reactive oxygen species damage liver tissues. In this study, we examined whether ginsenoside-free molecules (GFMs) from steam-dried ginseng berries promote ethanol metabolism and scavenge free radicals by stimulating primary enzymes (alcohol dehydrogenase, aldehyde dehydrogenase, CYP2E1, and catalase) and antioxidant effects using in vitro and in vivo models. The results revealed that GFM effectively scavenged 2,2-diphenyl-1-picrylhydrazyl hydrate radicals and hydroxyl radicals. Notably, GFM significantly enhanced the expression of primary enzymes within 2 h in HepG2 cells. GFM clearly removed the consumed ethanol and significantly reduced the level of acetaldehyde as well as enhancement of primary gene expression in BALB/c mice. Moreover, GFM successfully protected HepG2 cells from ethanol attack. Of the major components identified in GFM, it was believed that linoleic acid was the most active ingredient. Based on these findings, we conclude that GFM holds promise for use as a new candidate for ethanol metabolism and as an antihangover agent. PMID:24962619

  5. The Oxidative Fermentation of Ethanol in Gluconacetobacter diazotrophicus Is a Two-Step Pathway Catalyzed by a Single Enzyme: Alcohol-Aldehyde Dehydrogenase (ADHa

    Directory of Open Access Journals (Sweden)

    Saúl Gómez-Manzo

    2015-01-01

    Full Text Available Gluconacetobacter diazotrophicus is a N2-fixing bacterium endophyte from sugar cane. The oxidation of ethanol to acetic acid of this organism takes place in the periplasmic space, and this reaction is catalyzed by two membrane-bound enzymes complexes: the alcohol dehydrogenase (ADH and the aldehyde dehydrogenase (ALDH. We present strong evidence showing that the well-known membrane-bound Alcohol dehydrogenase (ADHa of Ga. diazotrophicus is indeed a double function enzyme, which is able to use primary alcohols (C2–C6 and its respective aldehydes as alternate substrates. Moreover, the enzyme utilizes ethanol as a substrate in a reaction mechanism where this is subjected to a two-step oxidation process to produce acetic acid without releasing the acetaldehyde intermediary to the media. Moreover, we propose a mechanism that, under physiological conditions, might permit a massive conversion of ethanol to acetic acid, as usually occurs in the acetic acid bacteria, but without the transient accumulation of the highly toxic acetaldehyde.

  6. Effects of 20 Selected Fruits on Ethanol Metabolism: Potential Health Benefits and Harmful Impacts

    Science.gov (United States)

    Zhang, Yu-Jie; Wang, Fang; Zhou, Yue; Li, Ya; Zhou, Tong; Zheng, Jie; Zhang, Jiao-Jiao; Li, Sha; Xu, Dong-Ping; Li, Hua-Bin

    2016-01-01

    The consumption of alcohol is often accompanied by other foods, such as fruits and vegetables. This study is aimed to investigate the effects of 20 selected fruits on ethanol metabolism to find out their potential health benefits and harmful impacts. The effects of the fruits on ethanol metabolism were characterized by the concentrations of ethanol and acetaldehyde in blood, as well as activities of alcohol dehydrogenase and acetaldehyde dehydrogenase in liver of mice. Furthermore, potential health benefits and harmful impacts of the fruits were evaluated by biochemical parameters including aspartate transaminase (AST), alanine transferase (ALT), malondialdehyde, and superoxide dismutase. Generally, effects of these fruits on ethanol metabolism were very different. Some fruits (such as Citrus limon (yellow), Averrhoa carambola, Pyrus spp., and Syzygium samarangense) could decrease the concentration of ethanol in blood. In addition, several fruits (such as Cucumis melo) showed hepatoprotective effects by significantly decreasing AST or ALT level in blood, while some fruits (such as Averrhoa carambola) showed adverse effects. The results suggested that the consumption of alcohol should not be accompanied by some fruits, and several fruits could be developed as functional foods for the prevention and treatment of hangover and alcohol use disorder. PMID:27043608

  7. Design and development of a new generation of UV-visible-light-driven nanosized codoped titanium dioxide photocatalysts and biocides/sporocides, and environmental applications

    Science.gov (United States)

    Hamal, Dambar B.

    For solar environmental remediation, a new generation of nanosized (carbon and sulfur) is necessary to achieve high-activities for acetaldehyde degradation under visible light (wavelength > 420 nm). It was concluded that high visible-light-activities for acetaldehyde degradation over codoped titanium dioxide were attributed to an interplay of anatase crystallinity, high-surface area, reduced band-gap (doped metal ions, and suppressed recombination rate of photogenerated electronhole pairs. Moreover, the nature and amount of codoped metals play a significant role in visible-light-induced photocatalysis. Metals (Al, Ga, and In) doped/codoped titanium dioxide photocatalysts were prepared by the aero-gel method. The photocatalytic studies showed that activities of metal doped/codoped photocatalysts under UV light (wavelength carbon, and sulfur codoped titanium dioxide nanoparticles ( 8) and B. subtilis spores (logarithmic kill > 5) for 30 minute exposures in dark conditions compared with Degussa P25. It was believed that the carbon and sulfur codoped titanium dioxide support and Ag species acted synergistically during deactivation of both E. coli and B. subtilis spores. Thus, titanium dioxide codoped with silver, carbon, sulfur can serve as a multifunctional generic biocide and a visible-light-active photocatalyst.

  8. Amine-functionalized porous silicas as adsorbents for aldehyde abatement.

    Science.gov (United States)

    Nomura, Akihiro; Jones, Christopher W

    2013-06-26

    A series of aminopropyl-functionalized silicas containing of primary, secondary, or tertiary amines is fabricated via silane-grafting on mesoporous SBA-15 silica and the utility of each material in the adsorption of volatile aldehydes from air is systematically assessed. A particular emphasis is placed on low-molecular-weight aldehydes such as formaldehyde and acetaldehyde, which are highly problematic volatile organic compound (VOC) pollutants. The adsorption tests demonstrate that the aminosilica materials with primary amines most effectively adsorbed formaldehyde with an adsorption capacity of 1.4 mmolHCHO g(-1), whereas the aminosilica containing secondary amines showed lower adsorption capacity (0.80 mmolHCHO g(-1)) and the aminosilica containing tertiary amines adsorbed a negligible amount of formaldehyde. The primary amine containing silica also successfully abated higher aldehyde VOC pollutants, including acetaldehyde, hexanal, and benzaldehyde, by effectively adsorbing them. The adsorption mechanism is investigated by (13)C CP MAS solid-state NMR and FT-Raman spectroscopy, and it is demonstrated that the aldehydes are chemically attached to the surface of aminosilica in the form of imines and hemiaminals. The high aldehyde adsorption capacities of the primary aminosilicas in this study demonstrate the utility of amine-functionalized silica materials for reduction of gaseous aldehydes.

  9. Potential effects of using biodiesel in road-traffic on air quality over the Porto urban area, Portugal

    Science.gov (United States)

    Ribeiro, Isabel; Monteiro, Alexandra; Lopes, Myriam

    2016-01-01

    This work aims to assess the impacts of biodiesel blends use in road-traffic on air quality. In this frame, the air quality numerical modelling system WRF-EURAD was applied over Portugal and the Porto urban area, forced by two emission scenarios (including CO, NOx, PM10, PM2.5, NMVOC, formaldehyde, acetaldehyde, acrolein and benzene): a reference scenario, without biofuels, and a scenario where a B20 fuel (20% biodiesel/80% diesel, v/v) is used by the diesel vehicle fleet. Regarding carbonyl compounds, emission scenarios pointed out that B20 fuel can promote an increase of 20% on formaldehyde, acetaldehyde and acrolein emissions, leading to increments on equivalent ozone production. On the other hand, through the air quality modelling exercise, it was verified that the use of B20 helps in controlling air pollution, improving CO and NO2 concentrations in urban airshed in about 20% and 10%, respectively, taking into account a regional simulation grid. However, according to the urban scale simulation, NO2 levels can increase in about 1%, due to the use of B20, over the Porto urban area. For the remaining studied pollutants, namely PM10 and PM2.5, mean concentrations will be reduced all over the territory, however in a negligible amount of <1%.

  10. Ambient measurements of aromatic and oxidized VOCs by PTR-MS and GC-MS: intercomparison between four instruments in a boreal forest in Finland

    Science.gov (United States)

    Kajos, M. K.; Rantala, P.; Hill, M.; Hellén, H.; Aalto, J.; Patokoski, J.; Taipale, R.; Hoerger, C. C.; Reimann, S.; Ruuskanen, T. M.; Rinne, J.; Petäjä, T.

    2015-04-01

    Proton transfer reaction mass spectrometry (PTR-MS) and gas chromatography mass spectrometry GC-MS) allow real-time measurements of various atmospheric volatile organic compounds (VOC). By taking parallel measurements in ambient conditions, two PTR-MSs and two GC-MSs were studied for their ability to measure methanol, acetaldehyde, acetone, benzene and toluene. The measurements were conducted at a rural boreal forest site in southern Finland between 13 April and 14 May 2012. This paper presents correlations and possible biases between the concentrations measured using the four instruments. This paper presents correlations and possible biases between the concentrations measured using the four instruments. A very good correlation was found for benzene and acetone measurements between all instruments (the mean R value was 0.88 for both compounds), while for acetaldehyde and toluene the correlation was weaker (with a mean R value of 0.50 and 0.62, respectively). For some compounds, notably for methane, there were considerable systematic differences in the mixing ratios measured by the different instruments, despite the very good correlation between the instruments (mean R = 0.90). The systematic difference arises as a difference in the linear regression slope between measurements conducted between instruments, rather than as an offset. This mismatch indicates that the systematic uncertainty in the sensitivity of a given instrument can lead to an uncertainty of 50-100% in the methanol emissions measured by commonly used methods.

  11. Sources, Sinks and Cycling of Acetyl Radicals in Tobacco Smoke: A Model for Biomass Burning Chemistry

    Science.gov (United States)

    Hu, N.; Green, S. A.

    2012-12-01

    Smoke near the source of biomass burning contains high concentrations of reactive compounds, with NO and CH3CHO concentrations four to six orders of magnitude higher than those in the ambient atmosphere. Tobacco smoke represents a special case of biomass burning that is quite reproducible in the lab and may elucidate early processes in smoke from other sources. The origins, identities, and reactions of radical species in tobacco smoke are not well understood, despite decades of study on the concentrations and toxicities of the relatively stable compounds in smoke. We propose that reactions of NO2 and aldehydes are a primary source for transient free radicals in tobacco smoke, which contrasts with the long-surmised mechanism of reaction between NO2 and dienes. The objective of this study was to investigate the sources, sinks and cycling of acetyl radical in tobacco smoke. Experimentally, the production of acetyl radical was demonstrated both in tobacco smoke and in a simplified mixture of air combined with NO and acetaldehyde, both of which are significant components of smoke. Acetyl radicals were trapped from the gas phase using 3-amino-2, 2, 5, 5-tetramethyl-proxyl (3AP) on solid support to form stable 3AP adducts for later analysis by high performance liquid chromatography (HPLC), mass spectrometry/tandem mass spectrometry (MS-MS/MS) and liquid chromatography-mass spectrometry (LC-MS). The dynamic nature of radical cycling in smoke makes it impossible to define a fixed concentration of radical species; 2.15×e13-3.18×e14 molecules/cm3 of acetyl radicals were measured from different cigarette samples and smoking conditions. Matlab was employed to simulate reactions of NO, NO2, O2, and a simplified set of organic compounds known to be present in smoke, with a special emphasis on acetaldehyde and the acetyl radical. The NO2/acetaldehyde mechanism initiates a cascade of chain reactions, which accounts for the most prevalent known carbon-centered radicals found in

  12. Citric acid reduces the decline in P300 amplitude induced by acute alcohol consumption in healthy adults

    Institute of Scientific and Technical Information of China (English)

    Wei-xing CHEN; Chuan-qin XU; Shao-hua CHEN; Gen-yun XU; Huai-zhuang YE

    2012-01-01

    Event-related potential (ERP) is a reliable neuroelectric measure of brain activity that helps to confirm the assessment of mental status and cognitive impairment.Many studies have reported that alcoholics show a significantly lower ERP P300 amplitude than the norm.In the present study,ERP P300 waves were measured to evaluate the effect of citric acid on cognitive function during excessive alcohol consumption in healthy adults.Five volunteers were selected through clinical interview,physical examination,and psychiatric assessment for participation in this study.In a double-blind placebo-controlled before-after design,each subject was treated with 5 ml/kg body weight alcohol,5 ml/kg body weight alcohol and 1 mg citric acid,or a placebo on three separate occasions,one week apart.ERP P300,blood biochemical indicators,blood alcohol concentrations (BACs) and acetaldehyde concentrations were assessed.Repeated measure analysis of variance (ANOVA) with a within-subjects factor was used to evaluate differences in blood biochemical indicators,BACs,blood acetaldehyde concentrations,and ERP P300 in the three sessions of assessments.Several blood biochemical indicators showed significant differences between treatments,including the levels of cholinesterase (CHE),total bile acid (TBA),triglyceride (TG),total cholesterol (TC),high-density lipoprotein cholesterol (HDL-C),low-density lipoprotein cholesterol (LDL-C),very low-density lipoprotein cholesterol (VLDL-C),and glycylproline dipeptidyl aminopeptidase (GPDA).BACs after consumption of alcohol alone or citric acid with alcohol were significantly higher compared to those after placebo treatment (P<0.05).There were no significant differences in blood acetaldehyde concentrations between the treatments.The P300 amplitudes on the frontal (Fz),central (Cz),and parietal (Pz) regions of the scalp after consumption of alcohol were significantly lower than those after consumption of the placebo or citric acid with alcohol (P<0

  13. 番茄柚子梨混合果汁醒酒作用的研究%Research of the sobering up function of fruit juice mixed of tomato pomelo and pear

    Institute of Scientific and Technical Information of China (English)

    华景清; 黄超群; 王琪; 吴飞

    2013-01-01

    The garden stuff have polyphenol,various of organic acid,vitamin,and nutrients.All these made alcohol dehydrogenase and acetaldehyde dehydrogenase more active,and hasten the metabolism of alcohol.These also decomposed acetaldehyde which was produced by alcohol,and promoted it to translate into carbon dioxide and water that would be excreted from the body.Consequently it reduces or eliminates the injury caused by acetaldehyde,and relieved some untoward reaction such as dizziness,nausea,vomit and so on.With the study of the effect of drinking the mixed fruit juice including tomato pomelo and pear on sobering intoxicated person up,according to single factor experiment and orthogonal experiment that drinking mixed fruit juice (100mL) after drinking test alcohol(2ml/kg)half an hour later.It was found that the most effective combination was 25% tomato juice,20% pomelo juice and 25% pear juice.%果蔬中含有的多元酚成分,加上多种有机酸、维生素以及营养物质,使乙醇脱氢酶、乙醛脱氢酶活性大大提高,加速酒精的代谢,分解酒精在人体内产生的有害物质乙醛,加速其转化为乙酸、二氧化碳和水,最终排出体外.从而减轻或消除乙醛对人体的伤害,缓解酒后头晕、恶心、呕吐等不良反应.本文采用单因素实验、正交实验研究番茄汁、柚子汁与梨汁混合果汁对动物、人体醒酒效果,发现以2mL/kg的量服用实验用酒,30min后服用l00mL的混合果汁,其中番茄汁含量25%,柚子汁含量20%,梨汁含量25%时,混合果汁具有最优醒酒作用.

  14. In situ measurements and modeling of reactive trace gases in a small biomass burning plume

    Science.gov (United States)

    Müller, Markus; Anderson, Bruce E.; Beyersdorf, Andreas J.; Crawford, James H.; Diskin, Glenn S.; Eichler, Philipp; Fried, Alan; Keutsch, Frank N.; Mikoviny, Tomas; Thornhill, Kenneth L.; Walega, James G.; Weinheimer, Andrew J.; Yang, Melissa; Yokelson, Robert J.; Wisthaler, Armin

    2016-03-01

    An instrumented NASA P-3B aircraft was used for airborne sampling of trace gases in a plume that had emanated from a small forest understory fire in Georgia, USA. The plume was sampled at its origin to derive emission factors and followed ˜ 13.6 km downwind to observe chemical changes during the first hour of atmospheric aging. The P-3B payload included a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS), which measured non-methane organic gases (NMOGs) at unprecedented spatiotemporal resolution (10 m spatial/0.1 s temporal). Quantitative emission data are reported for CO2, CO, NO, NO2, HONO, NH3, and 16 NMOGs (formaldehyde, methanol, acetonitrile, propene, acetaldehyde, formic acid, acetone plus its isomer propanal, acetic acid plus its isomer glycolaldehyde, furan, isoprene plus isomeric pentadienes and cyclopentene, methyl vinyl ketone plus its isomers crotonaldehyde and methacrolein, methylglyoxal, hydroxy acetone plus its isomers methyl acetate and propionic acid, benzene, 2,3-butanedione, and 2-furfural) with molar emission ratios relative to CO larger than 1 ppbV ppmV-1. Formaldehyde, acetaldehyde, 2-furfural, and methanol dominated NMOG emissions. No NMOGs with more than 10 carbon atoms were observed at mixing ratios larger than 50 pptV ppmV-1 CO. Downwind plume chemistry was investigated using the observations and a 0-D photochemical box model simulation. The model was run on a nearly explicit chemical mechanism (MCM v3.3) and initialized with measured emission data. Ozone formation during the first hour of atmospheric aging was well captured by the model, with carbonyls (formaldehyde, acetaldehyde, 2,3-butanedione, methylglyoxal, 2-furfural) in addition to CO and CH4 being the main drivers of peroxy radical chemistry. The model also accurately reproduced the sequestration of NOx into peroxyacetyl nitrate (PAN) and the OH-initiated degradation of furan and 2-furfural at an average OH concentration of 7.45 ± 1.07 × 106 cm-3 in the

  15. Inhibition of human alcohol and aldehyde dehydrogenases by acetaminophen: Assessment of the effects on first-pass metabolism of ethanol.

    Science.gov (United States)

    Lee, Yung-Pin; Liao, Jian-Tong; Cheng, Ya-Wen; Wu, Ting-Lun; Lee, Shou-Lun; Liu, Jong-Kang; Yin, Shih-Jiun

    2013-11-01

    Acetaminophen is one of the most widely used over-the-counter analgesic, antipyretic medications. Use of acetaminophen and alcohol are commonly associated. Previous studies showed that acetaminophen might affect bioavailability of ethanol by inhibiting gastric alcohol dehydrogenase (ADH). However, potential inhibitions by acetaminophen of first-pass metabolism (FPM) of ethanol, catalyzed by the human ADH family and by relevant aldehyde dehydrogenase (ALDH) isozymes, remain undefined. ADH and ALDH both exhibit racially distinct allozymes and tissue-specific distribution of isozymes, and are principal enzymes responsible for ethanol metabolism in humans. In this study, we investigated acetaminophen inhibition of ethanol oxidation with recombinant human ADH1A, ADH1B1, ADH1B2, ADH1B3, ADH1C1, ADH1C2, ADH2, and ADH4, and inhibition of acetaldehyde oxidation with recombinant human ALDH1A1 and ALDH2. The investigations were done at near physiological pH 7.5 and with a cytoplasmic coenzyme concentration of 0.5 mM NAD(+). Acetaminophen acted as a noncompetitive inhibitor for ADH enzymes, with the slope inhibition constants (Kis) ranging from 0.90 mM (ADH2) to 20 mM (ADH1A), and the intercept inhibition constants (Kii) ranging from 1.4 mM (ADH1C allozymes) to 19 mM (ADH1A). Acetaminophen exhibited noncompetitive inhibition for ALDH2 (Kis = 3.0 mM and Kii = 2.2 mM), but competitive inhibition for ALDH1A1 (Kis = 0.96 mM). The metabolic interactions between acetaminophen and ethanol/acetaldehyde were assessed by computer simulation using inhibition equations and the determined kinetic constants. At therapeutic to subtoxic plasma levels of acetaminophen (i.e., 0.2-0.5 mM) and physiologically relevant concentrations of ethanol (10 mM) and acetaldehyde (10 μm) in target tissues, acetaminophen could inhibit ADH1C allozymes (12-26%) and ADH2 (14-28%) in the liver and small intestine, ADH4 (15-31%) in the stomach, and ALDH1A1 (16-33%) and ALDH2 (8.3-19%) in all 3 tissues. The

  16. Genetic polymorphisms of alcohol dehydrogense-1B and aldehyde dehydrogenase-2, alcohol flushing, mean corpuscular volume, and aerodigestive tract neoplasia in Japanese drinkers.

    Science.gov (United States)

    Yokoyama, Akira; Mizukami, Takeshi; Yokoyama, Tetsuji

    2015-01-01

    Genetic polymorphisms of alcohol dehydrogenase-1B (ADH1B) and aldehyde dehydrogenase-2 (ALDH2) modulate exposure levels to ethanol/acetaldehyde. Endoscopic screening of 6,014 Japanese alcoholics yielded high detection rates of esophageal squamous cell carcinoma (SCC; 4.1%) and head and neck SCC (1.0%). The risks of upper aerodigestive tract SCC/dysplasia, especially of multiple SCC/dysplasia, were increased in a multiplicative fashion by the presence of a combination of slow-metabolizing ADH1B*1/*1 and inactive heterozygous ALDH2*1/*2 because of prolonged exposure to higher concentrations of ethanol/acetaldehyde. A questionnaire asking about current and past facial flushing after drinking a glass (≈180 mL) of beer is a reliable tool for detecting the presence of inactive ALDH2. We invented a health-risk appraisal (HRA) model including the flushing questionnaire and drinking, smoking, and dietary habits. Esophageal SCC was detected at a high rate by endoscopic mass-screening in high HRA score persons. A total of 5.0% of 4,879 alcoholics had a history of (4.0%) or newly diagnosed (1.0%) gastric cancer. Their high frequency of a history of gastric cancer is partly explained by gastrectomy being a risk factor for alcoholism because of altered ethanol metabolism, e.g., by blood ethanol level overshooting. The combination of H. pylori-associated atrophic gastritis and ALDH2*1/*2 showed the greatest risk of gastric cancer in alcoholics. High detection rates of advanced colorectal adenoma/carcinoma were found in alcoholics, 15.7% of 744 immunochemical fecal occult blood test (IFOBT)-negative alcoholics and 31.5% of the 393 IFOBT-positive alcoholics. Macrocytosis with an MCV≥106 fl increased the risk of neoplasia in the entire aerodigestive tract of alcoholics, suggesting that poor nutrition as well as ethanol/acetaldehyde exposure plays an important role in neoplasia. PMID:25427912

  17. Safety evaluation of topical applications of ethanol on the skin and inside the oral cavity

    Directory of Open Access Journals (Sweden)

    Lachenmeier Dirk W

    2008-11-01

    Full Text Available Abstract Ethanol is widely used in all kinds of products with direct exposure to the human skin (e.g. medicinal products like hand disinfectants in occupational settings, cosmetics like hairsprays or mouthwashes, pharmaceutical preparations, and many household products. Contradictory evidence about the safety of such topical applications of the alcohol can be found in the scientific literature, yet an up-to-date risk assessment of ethanol application on the skin and inside the oral cavity is currently lacking. The first and foremost concerns of topical ethanol applications for public health are its carcinogenic effects, as there is unambiguous evidence for the carcinogenicity of ethanol orally consumed in the form of alcoholic beverages. So far there is a lack of evidence to associate topical ethanol use with an increased risk of skin cancer. Limited and conflicting epidemiological evidence is available on the link between the use of ethanol in the oral cavity in the form of mouthwashes or mouthrinses and oral cancer. Some studies pointed to an increased risk of oral cancer due to locally produced acetaldehyde, operating via a similar mechanism to that found after alcoholic beverage ingestion. In addition, topically applied ethanol acts as a skin penetration enhancer and may facilitate the transdermal absorption of xenobiotics (e.g. carcinogenic contaminants in cosmetic formulations. Ethanol use is associated with skin irritation or contact dermatitis, especially in humans with an aldehyde dehydrogenase (ALDH deficiency. After regular application of ethanol on the skin (e.g. in the form of hand disinfectants relatively low but measurable blood concentrations of ethanol and its metabolite acetaldehyde may occur, which are, however, below acute toxic levels. Only in children, especially through lacerated skin, can percutaneous toxicity occur. As there might be industry bias in many studies about the safety of topical ethanol applications, as well

  18. Acetylene Fermentation: Relevance to Primordial Biogeochemistry and the Search for Life in the Outer Solar System

    Science.gov (United States)

    Oremland, R. S.; Baesman, S. M.; Miller, L. G.

    2013-12-01

    Acetylene is a highly reactive component of planet(oid)s with anoxic, methane-rich atmospheres, such as Jupiter, Saturn, Titan, and perhaps the primordial Earth. Included in this group is Enceladus, although it is not clear if the acetylene detected within its jets by Cassini was formed by photolysis of methane, from thermo-catalysis of organic matter in the orb's interior, or a fragmentation artifact of the mass spectrum of a larger hydrocarbon. Acetylene inhibits many microbial processes (e.g., methanogenesis, methane oxidation, hydrogen metabolism, denitrification) yet a number of anaerobes can use it as a carbon and energy source to support growth. The best studied is Pelobacter acetylenicus, which carries out a two-step reaction involving the enzymes acetylene hydratase and acetaldehyde dismutase. The former, a low potential W-containing enzyme, forms acetaldehyde while the latter produces ethanol and acetate. Metabolism of acetylene by mixed microbial communities (sediments and/or enrichment cultures) produces these intermediates, and when coupled with sulfate-reduction or methanogenesis respectively forms CO2 or an equal mixtures of CO2 plus CH4. It is not inconceivable that such an anaerobic, microbial food chain could exist in the waters beneath the ice cap of Enceladus, Titan, or even in the mesothermal atmospheric regions of the gas giants. Detection of the identified intermediate products of acetylene fermentation, namely acetaldehyde, ethanol, acetate and formate in the atmospheres of these planet(oid)s would constitute evidence for a microbial life signature. This evidence would be strongly reinforced if a stable carbon isotope fractionation was identified as well, whereby the products of acetylene fermentation were enriched in 12C relative to 13C (i.e., had a lighter δ13C signal) when compared to that of the starting acetylene. The most practical target to test this hypothesis would be Enceladus (if the detected acetylene is shown to be a real

  19. Gas phase carbonyl compounds in ship emissions: Differences between diesel fuel and heavy fuel oil operation

    Science.gov (United States)

    Reda, Ahmed A.; Schnelle-Kreis, J.; Orasche, J.; Abbaszade, G.; Lintelmann, J.; Arteaga-Salas, J. M.; Stengel, B.; Rabe, R.; Harndorf, H.; Sippula, O.; Streibel, T.; Zimmermann, R.

    2014-09-01

    Gas phase emission samples of carbonyl compounds (CCs) were collected from a research ship diesel engine at Rostock University, Germany. The ship engine was operated using two different types of fuels, heavy fuel oil (HFO) and diesel fuel (DF). Sampling of CCs was performed from diluted exhaust using cartridges and impingers. Both sampling methods involved the derivatization of CCs with 2,4-Dinitrophenylhydrazine (DNPH). The CCs-hydrazone derivatives were analyzed by two analytical techniques: High Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD) and Gas Chromatography-Selective Ion Monitoring-Mass Spectrometry (GC-SIM-MS). Analysis of DNPH cartridges by GC-SIM-MS method has resulted in the identification of 19 CCs in both fuel operations. These CCs include ten aliphatic aldehydes (formaldehyde, acetaldehyde, propanal, isobutanal, butanal, isopentanal, pentanal, hexanal, octanal, nonanal), three unsaturated aldehydes (acrolein, methacrolein, crotonaldehyde), three aromatic aldehyde (benzaldehyde, p-tolualdehyde, m,o-molualdehyde), two ketones (acetone, butanone) and one heterocyclic aldehyde (furfural). In general, all CCs under investigation were detected with higher emission factors in HFO than DF. The total carbonyl emission factor was determined and found to be 6050 and 2300 μg MJ-1 for the operation with HFO and DF respectively. Formaldehyde and acetaldehyde were found to be the dominant carbonyls in the gas phase of ship engine emission. Formaldehyde emissions factor varied from 3500 μg MJ-1 in HFO operation to 1540 μg MJ-1 in DF operation, which is 4-30 times higher than those of other carbonyls. Emission profile contribution of CCs showed also a different pattern between HFO and DF operation. The contribution of formaldehyde was found to be 58% of the emission profile of HFO and about 67% of the emission profile of DF. Acetaldehyde showed opposite behavior with higher contribution of 16% in HFO compared to 11% for DF. Heavier carbonyls

  20. In situ measurements and modeling of reactive trace gases in a small biomass burning plume

    Science.gov (United States)

    Müller, M.; Anderson, B.; Beyersdorf, A.; Crawford, J. H.; Diskin, G.; Eichler, P.; Fried, A.; Keutsch, F. N.; Mikoviny, T.; Thornhill, K. L.; Walega, J. G.; Weinheimer, A. J.; Yang, M.; Yokelson, R.; Wisthaler, A.

    2015-11-01

    An instrumented NASA P-3B aircraft was used for airborne sampling of trace gases in a plume that had emanated from a small forest understory fire in Georgia, USA. The plume was sampled at its origin for deriving emission factors and followed ~ 13.6 km downwind for observing chemical changes during the first hour of atmospheric aging. The P-3B payload included a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS), which measured non-methane organic gases (NMOGs) at unprecedented spatio-temporal resolution (10 m/0.1 s). Quantitative emission data are reported for CO2, CO, NO, NO2, HONO, NH3 and 16 NMOGs (formaldehyde, methanol, acetonitrile, propene, acetaldehyde, formic acid, acetone plus its isomer propanal, acetic acid plus its isomer glycolaldehyde, furan, isoprene plus isomeric pentadienes and cyclopentene, methyl vinyl ketone plus its isomers crotonaldehyde and methacrolein, methylglyoxal, hydroxy acetone plus its isomers methyl acetate and propionic acid, benzene, 2,3-butandione and 2-furfural) with molar emission ratios relative to CO larger than 1 ppbV ppmV-1. Formaldehyde, acetaldehyde, 2-furfural and methanol dominated NMOG emissions. No NMOGs with more than 10 carbon atoms were observed at mixing ratios larger than 50 ppbV ppmV-1 CO emitted. Downwind plume chemistry was investigated using the observations and a 0-D photochemical box model simulation. The model was run on a near-explicit chemical mechanism (MCM v3.3) and initialized with measured emission data. Ozone formation during the first hour of atmospheric aging was well captured by the model, with carbonyls (formaldehyde, acetaldehyde, 2,3-butanedione, methylglyoxal, 2-furfural) in addition to CO and CH4 being the main drivers of peroxy radical chemistry. The model also accurately reproduced the sequestration of NOx into PAN and the OH-initiated degradation of furan and 2-furfural at an average OH concentration of 7.45 ± 1.07 × 106 cm-3 in the plume. Formaldehyde, acetone

  1. 乙醇溶剂中硝酸银与氢氧化钠的反应机理%The mechanism of reaction of silver nitrate with sodium hydroxide in ethanol

    Institute of Scientific and Technical Information of China (English)

    王雷雷; 赵苗芝; 薛永强

    2012-01-01

    在乙醇溶剂中制备纳米Ag2O时,发现有纳米Ag2O和纳米Ag2种产物,进而通过XRD对其反应机理进行了研究.实验结果和理论分析表明,溶剂对制备纳米氧化银有很大影响,在乙醇溶剂中不能制备出纯的纳米氧化银;其反应机理为该反应首先是银离子与氢氧根离子反应生成氧化银沉淀,氧化银在碱性条件下将溶剂乙醇氧化为乙醛,而自身被还原为单质银;生成的乙醛又将银离子和氧化银还原为单质银,从而导致产物既有纳米氧化银又有纳米银;其中碱性介质是氧化银将乙醇氧化为乙醛的催化剂.%Two kinds of products, nano-Ag2O and nano-Ag were found in preparing nano-Ag2O by ethanol solvent;and then the mechanism of this reaction was investigated by XRD. The experimental results and theoretical analysis showed that the solvent has a great influence on the preparation of nano-silver oxide, and pure nano-Ag2O can not be obtained in ethanol solvent. And that this reaction mechanism is that first, silver ion reacts with hydroxyl ion and the precipitation of silver oxide is produced; under alkaline condition,ethanol solvent is oxidated to acetaldehyde by the silver oxide,and itself is reduced to silver;the silver ions and silver oxide are reduced to silver by acetaldehyde, resulting in two products: nano-silver oxide and nano-silver;in the reaction,the alkaline medium is the catalyst for oxidating ethanol to acetaldehyde by silver oxide.

  2. Gas-Chromatographic Analysis of Major Volatile Compounds Found in Traditional Fruit Brandies from Transylvania, Romania

    Directory of Open Access Journals (Sweden)

    Teodora Emilia RUSU COLDEA

    2011-11-01

    Full Text Available In the current study, the major volatile compounds from three categories of traditional fruit brandies (plum, apple and pear were characterized by gas-chromatography (GC-FID. There were collected 26 samples from different locations of Transylvania (Romania, all made by traditional technologies involving fermentation in barrels and distillation in copper stills. The major volatile compounds, besides ethanol, identified and quantified were: acetaldehyde, ethyl acetate, methanol, 1-propanol, 2-butanol, iso-butylic alcohol, alcool amyl active, iso-amylic alcohol, 1-butanol and furfural. For each type of brandy, positive but no significant correlations between methanol and furfural concentrations in plum and apple brandy were noticed. To evaluate the differences in composition regarding the geographical origin of plum brandies and to analyze the composition of plum, apple and pear brandies it has been compared the mean values (MVP, MVA and MVPe obtained for each volatile. For plum brandies it has been observed differences among the mean values of each volatile, in samples originating from counties Cluj, Bistriţa-Năsăud and Maramureş. For methanol, acetaldehyde and 1-propanol the MVP Cluj values were significantly higher than MVP Bistriţa-Năsăud. For iso-butylic alcohol, amyl active alcohol, iso-amylic alcohol the MVP Cluj values were significantly higher than for Bistriţa-Năsăud and Maramureş, while for ethyl acetate and furfural the MVP Bistriţa-Năsăud were significantly higher than MVP Cluj and MVP Maramureş. When compared the mean values of volatiles in plum vs apple vs pear brandies, for ethyl acetate, methanol, 2-butanol, 1-propanol and 1-butanol, the MVPe values were significantly higher than MVA, for furfural, amyl active and iso-amylic alcohols, while for acetaldehyde the MVPe values were significantly higher than MVP. Methanol represented the major volatile component, characteristic to fruit brandies, released by enzymatic

  3. Safety evaluation of topical applications of ethanol on the skin and inside the oral cavity.

    Science.gov (United States)

    Lachenmeier, Dirk W

    2008-01-01

    Ethanol is widely used in all kinds of products with direct exposure to the human skin (e.g. medicinal products like hand disinfectants in occupational settings, cosmetics like hairsprays or mouthwashes, pharmaceutical preparations, and many household products). Contradictory evidence about the safety of such topical applications of the alcohol can be found in the scientific literature, yet an up-to-date risk assessment of ethanol application on the skin and inside the oral cavity is currently lacking.The first and foremost concerns of topical ethanol applications for public health are its carcinogenic effects, as there is unambiguous evidence for the carcinogenicity of ethanol orally consumed in the form of alcoholic beverages. So far there is a lack of evidence to associate topical ethanol use with an increased risk of skin cancer. Limited and conflicting epidemiological evidence is available on the link between the use of ethanol in the oral cavity in the form of mouthwashes or mouthrinses and oral cancer. Some studies pointed to an increased risk of oral cancer due to locally produced acetaldehyde, operating via a similar mechanism to that found after alcoholic beverage ingestion.In addition, topically applied ethanol acts as a skin penetration enhancer and may facilitate the transdermal absorption of xenobiotics (e.g. carcinogenic contaminants in cosmetic formulations). Ethanol use is associated with skin irritation or contact dermatitis, especially in humans with an aldehyde dehydrogenase (ALDH) deficiency.After regular application of ethanol on the skin (e.g. in the form of hand disinfectants) relatively low but measurable blood concentrations of ethanol and its metabolite acetaldehyde may occur, which are, however, below acute toxic levels. Only in children, especially through lacerated skin, can percutaneous toxicity occur.As there might be industry bias in many studies about the safety of topical ethanol applications, as well as a general lack of

  4. The {gamma} radiolysis at room temperature of liquid deaerated isopropanol; Radiolyse {gamma} a temperature ambiante de l'isopropanol liquide desaere

    Energy Technology Data Exchange (ETDEWEB)

    Gilles, L. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-02-01

    The main products formed in the room temperature {gamma} radiolysis of liquid isopropanol, and their respective yields, are: hydrogen 3.8, methane 1.6, acetone 3.4, acetaldehyde 1.1, and pinacol 0.3. These results give a material balance in good agreement with the formula of isopropanol and lead to a value for the yield of decomposition: 5, 3. The absence of butanediol 2.3 shows that the acetaldehyde cannot come from the dismutation of hydroxyethyl radicals. The variations of the hydrogen yield in the neutral medium with the concentration of added electron scavengers may be explained in terms of the model proposed by Freeman and FAYADH which supposes the existence of spurs. The yield of solvated electrons diffusing into the bulk of the solution and also the ratios of rate constants for the reactions of the scavengers with the electrons may likewise be obtained on the basis of this model. Certain effects not foreseen by this model may result from the capture of electrons solvated or not, whose mode of disappearance in pure alcohol remains unknown. One may distinguish a yield of excited molecules of at least 2, of which 80 per cent lead to the production of molecular hydrogen and 20 per cent to that of molecular methane, and an ionization yield of 2. 2. The discussion of the various mechanisms which may lead to the formation of the products indicates that these yields may be higher than the values quoted. (author) [French] Les principaux produits formes a temperature ambiante dans la radiolyse {gamma} de l'isopropanol liquide sont: l'hydrogene, le methane, l'acetone, l'acetaldehyde et le pinacol avec des rendements respectifs de 3,8 - 1,6 - 3,4 - 1,1 - 0,3. Le bilan de masse deduit de ces resultats est en bon accord avec la formule brute de l'isopropanol dont le rendement de decomposition est 5,3. L'absence de butanediol 2,3 montre que l'acetaldehyde ne peut provenir de la reaction de dismutation des radicaux hydroxyethyles. Le

  5. Electrocatalytic activity of surface adsorbed ruthenium-alizarin complexone toward the oxidation of benzyl alcohol

    International Nuclear Information System (INIS)

    The surface electrochemical behavior of an adsorbed alizarin complexone (abbreviated as AC) and its surface coordination with Ru(II) were studied in aqueous solution at a pH range of 0-6. The surface complex of ruthenium with AC displays strong electrocatalytic activities toward benzyl alcohol. Based on the rotating disk electrode measurement, it is believed that the electrocatalytic oxidation of benzyl alcohol is a two-electron and two-proton process with benzaldehyde as a major product. On the other hand, ruthenium-AC surface complex has also shown catalytic activities toward electro-oxidation of several small organic molecules such as methanol, formic acid, formaldehyde, ethanol, and acetaldehyde

  6. Research into aroma changes in irradiated foodstuffs. I.- Studies on Fish

    International Nuclear Information System (INIS)

    Radiolytic formation of volatile compounds have been investigated in fillets of hake, codfish and bonito gamma-irradiated at a dose range of 0.1-5 Mrads. Analytical methods have been developed by gas chromatography of functional group derivatives: carbonyls as 2,4,-dinitrophenyl hydrazones, primary and secondary amines as N-alkyl benzamides, and thiols as 2,4-dinitrophenyl alkyl thioethers. The main results are as follows: increasing with the integral dose of the whole carbonyls, the most significant components being acetaldehyde, propional dehyde and formaldehyde; no significant variations with the integral dose od the traces of ammonia, methylamine, trimethylamine, ethylamine, diethylamine, propylamine, butylamine and pentylamine found in unirradiated samples; and radiolytic formation of methanethiol and dimethyl disulfide. (Author) 98 refs

  7. Uma síntese alternativa para o (±-1,2,3,4-tetraidro-{9H-pirido-[3,4-b]}-indol An alternative synthesis of 1,2,3,4-tetrahydro-9H-pyrido-[3,4-b]-indole

    Directory of Open Access Journals (Sweden)

    Arildo José Braz de Oliveira

    2003-09-01

    Full Text Available O 1,2,3,4-tetraidro-9H-pirido-[3,4-b]-indol, um composto com propriedades tranqüilizantes, foi preparado a partir do 3-indol-acetaldeído e triptamina através de uma reação de condensação de Pictet-Spengler. Os dados físicos e espectrais do composto são apresentados.The 1,2,3,4-tetrahydro-9H-pyrido-[3,4-b]-indole, a compound with tranquillizing properties, was prepared in 16% overall yield from the 3-indole-acetaldehyde and tryptamine by applying the classical Pictet-Spengler condensation. Physical and spectroscopic data for such compound are presented.

  8. Application of high silica zeolite ZSM-5 in a hybrid treatment process based on sequential adsorption and ozonation for VOCs elimination.

    Science.gov (United States)

    Zaitan, Hicham; Manero, Marie Hélène; Valdés, Héctor

    2016-03-01

    In this study, a hydrophobic synthetic zeolite, namely ZSM-5 is chosen as an adsorbent/catalyst for toluene removal. Experimental results showed that toluene adsorption onto ZSM-5 was favourable, following a Langmuir adsorption isotherm model. ZSM-5 zeolite was regenerated using gaseous ozone at low temperature. Adsorbed toluene was oxidised, releasing mainly CO2 and H2O. Traces of oxidation by-products such as acetic acid and acetaldehyde were formed and remained adsorbed after the oxidativate regeneration with ozone. After four successive cycles of adsorption/ozonation, the adsorption efficiency was not affected (92%-99%). These results showed that volatile organic compound (VOC) removal by adsorption onto ZSM-5 zeolite followed by ozone regeneration could be used as a promising hybrid process for the control of VOC emissions in terms of efficiency.

  9. Yield optimization in a cycled trickle-bed reactor: ethanol catalytic oxidation as a case study

    Energy Technology Data Exchange (ETDEWEB)

    Ayude, A.; Haure, P. [INTEMA, CONICET, Mar del Plata (Argentina); Cassanello, M. [Universidad de Buenos Aires, PINMATE, Departamento de Industrias, FCEyN, Buenos Aires (Argentina); Martinez, O. [Departamento de Ingenieria Quimica, FI-UNLP-CINDECA, La Plata (Argentina)

    2012-05-15

    The effect of slow ON-OFF liquid flow modulation on the yield of consecutive reactions is investigated for oxidation of aqueous ethanol solutions using a 0.5 % Pd/Al{sub 2}O{sub 3} commercial catalyst in a laboratory trickle-bed reactor. Experiments with modulated liquid flow rate (MLFR) were performed under the same hydrodynamic conditions (degree of wetting, liquid holdup) as experiments with constant liquid flow rate (CLFR). Thus, the impact of the duration of wet and dry cycles as well as the period can be independently investigated. Depending on cycling conditions, acetaldehyde or acetic acid production is favored with MLFR compared to CLFR. Results suggest both the opportunity and challenge of finding a way to tune the cycling parameters for producing the most appropriate product. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Estimation of gaseous mercury emissions in Germany. Inverse modelling of source strengths at the contaminated industrial site BSL Werk Schkopau

    Energy Technology Data Exchange (ETDEWEB)

    Krueger, O.; Ebinghaus, R.; Kock, H.H.; Richter-Politz, I.; Geilhufe, C.

    1998-12-31

    Anthropogenic emission sources of gaseous mercury at the contaminated industrial site BSL Werk Schkopau have been determined by measurements and numerical modelling applying a local dispersion model. The investigations are based on measurements from several field campaigns in the period of time between December 1993 and June 1994. The estimation of the source strengths was performed by inverse modelling using measurements as constraints for the dispersion model. Model experiments confirmed the applicability of the inverse modelling procedure for the source strength estimation at BSL Werk Schkopau. At the factory premises investigated, the source strengths of four source areas, among them three closed chlor-alkali productions, one partly removed acetaldehyde factory and additionaly one still producing chlor-alkali factory have been identified with an approximate total gaseous mercury emission of lower than 2.5 kg/day. (orig.)

  11. Expression, crystallization and preliminary X-ray crystallographic study of ethanolamine ammonia-lyase from Escherichia coli

    International Nuclear Information System (INIS)

    Ethanolamine ammonia-lyase from E. coli has been overexpressed, purified and crystallized. The crystals diffracted to 2.2 Å resolution using synchrotron radiation. Ethanolamine ammonia-lyase (EAL) catalyzes the adenosylcobalamin-dependent conversion of ethanolamine to acetaldehyde and ammonia. The wild-type enzyme shows a very low solubility. N-terminal truncation of the Escherichia coli EAL β-subunit dramatically increases the solubility of the enzyme without altering its catalytic properties. Two deletion mutants of the enzyme [EAL(βΔ4–30) and EAL(βΔ4–43)] have been overexpressed, purified and crystallized using the sitting-drop vapour-diffusion method. Crystals of EAL(βΔ4–30) and EAL(βΔ4–43) diffracted to approximately 8.0 and 2.1 Å resolution, respectively

  12. Synthesis, characterization and catalytic properties of nanocrystaline Y2O3-coated TiO2 in the ethanol dehydration reaction

    International Nuclear Information System (INIS)

    In the present study, TiO2 nano powder was partially coated with Y2O3 precursors generated by a sol-gel modified route. The system of nanocoated particles formed an ultra thin structure on the TiO2 surfaces. The modified nanoparticles were characterized by high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD) analysis, Zeta potential and surface area through N2 physisorption measurements. Bioethanol dehydration was used as a probe reaction to investigate the modifications on the nanoparticles surface. The process led to the obtainment of nanoparticles with important surface characteristics and catalytic behavior in the bioethanol dehydration reaction, with improved activity and particular selectivity in comparison to their non-coated analogs. The ethylene production was disfavored and selectivity toward acetaldehyde, hydrogen and ethane increased over modified nanoparticles. (author)

  13. Aerobic oxidation of aqueous ethanol using heterogeneous gold catalysts: Efficient routes to acetic acid and ethyl acetate

    DEFF Research Database (Denmark)

    Jørgensen, Betina; Christiansen, Sofie Egholm; Thomsen, M.L.D.;

    2007-01-01

    The aerobic oxidation of aqueous ethanol to produce acetic acid and ethyl acetate was studied using heterogeneous gold catalysts. Comparing the performance of Au/MgAl2O4 and Au/TiO2 showed that these two catalysts exhibited similar performance in the reaction. By proper selection of the reaction...... conditions, yields of 90-95% of acetic acid could be achieved at moderate temperatures and pressures. Based on our findings, a reaction pathway for the catalytic oxidation of ethanol via acetaldehyde to acetic acid is proposed, and the rate-determining step (RDS) in the mechanism is found to be the (possibly......, the possibilities for producing ethyl acetate by the aerobic oxidation of ethanol is also studied. At low ethanol concentrations, the main product is acetic acid; at concentrations >60 wt%, it is ethyl acetate....

  14. Ethanol and neuronal metabolism.

    Science.gov (United States)

    Mandel, P; Ledig, M; M'Paria, J R

    1980-01-01

    The effect of ethanol on membrane enzymes (Na+, K+ and Mg2+ ATPases, 5'-nucleotidase, adenylate cyclase) alcohol dehydrogenase, aldehyde dehydrogenase and superoxide dismutase were studied in nerve cells (established cell lines, primary cultures of chick and rat brain) cultured in the presence of 100 mM ethanol, and in total rat brain, following various ethanol treatments of the rats (20% ethanol as the sole liquid source, intraperitoneal injection). The results show a difference between neuronal and glial cells. Most of the observed changes in enzymatic activities returned rapidly to control values when ethanol was withdrawn from the culture medium or from the diet. Alcohol dehydrogenase was more stimulated by ethanol than aldehyde dehydrogenase; therefore acetaldehyde may be accumulated. The inhibition of superoxide dismutase activity may allow an accumulation of cytotoxic O2- radicals in nervous tissue and may explain the polymorphism of lesions brought about by alcohol intoxication. PMID:6264495

  15. Photochemistry of CO and H2O - Analysis of laboratory experiments and applications to the prebiotic earth's atmosphere

    Science.gov (United States)

    Wen, Jun-Shan; Pinto, Joseph P.; Yung, Yuk L.

    1989-01-01

    The role photochemical reactions in the early earth's atmosphere played in the prebiotic synthesis of simple organic molecules was examined, extending an earlier calculation of formaldehyde production rates to more reduced carbon species, such as methanol, methane, and acetaldehyde. The experimental results of Bar-Nun and Chang (1983) are simulated as an aid in the construction of the photochemical scheme and as a way of validating the model. The results indicate that some fraction of CO2 and H2 present in the primitive atmosphere could have been converted to simple organic molecules. The exact amount is dependent on the partial pressure of CO2 and H2 in the atmosphere and on what assumptions are made concerning the shape of the absorption spectra of CO2 and H2O.

  16. Photoactivation Studies of Zinc Porphyrin-Myoglobin System and Its Application for Light-Chemical Energy Conversion

    Directory of Open Access Journals (Sweden)

    Chin-Hao Chang, Yi-Ting Hu, Chen-Fu Lo, Liyang Luo, Hung-Ming Lin, Cheng-Hsiang Chang, Ching-Yao Lin, Eric Wei-Guang Diau, Tung-Kung Wu

    2011-01-01

    Full Text Available An artificial zinc porphyrin-myoglobin-based photo-chemical energy conversion system, consisting of ZnPP-Mb or ZnPE1-Mb as a photosensitizer, NADP+ as an electron acceptor, and triethanolamine as an electron donor, has been constructed to mimic photosystem I. The photoirradiated product is able to reduce a single-electron acceptor protein cytochrome c, but cannot catalyze the two-electron reduction of acetaldehyde by alcohol dehydrogenase, thus demonstrating a single electron transfer mechanism. Furthermore, the artificial system can bifunctionally promote oxidoredox reactions, depending on the presence or absence of a sacrificial electron donor, thus suggesting its potential application in electrochemical regeneration steps involved in chemical transformation and/or energy conversion.

  17. Photoactivation Studies of Zinc Porphyrin-Myoglobin System and Its Application for Light-Chemical Energy Conversion

    Science.gov (United States)

    Chang, Chin-Hao; Hu, Yi-Ting; Lo, Chen-Fu; Luo, Liyang; Lin, Hung-Ming; Chang, Cheng-Hsiang; Lin, Ching-Yao; Diau, Eric Wei-Guang; Wu, Tung-Kung

    2011-01-01

    An artificial zinc porphyrin-myoglobin-based photo-chemical energy conversion system, consisting of ZnPP-Mb or ZnPE1-Mb as a photosensitizer, NADP+ as an electron acceptor, and triethanolamine as an electron donor, has been constructed to mimic photosystem I. The photoirradiated product is able to reduce a single-electron acceptor protein cytochrome c, but cannot catalyze the two-electron reduction of acetaldehyde by alcohol dehydrogenase, thus demonstrating a single electron transfer mechanism. Furthermore, the artificial system can bifunctionally promote oxidoredox reactions, depending on the presence or absence of a sacrificial electron donor, thus suggesting its potential application in electrochemical regeneration steps involved in chemical transformation and/or energy conversion. PMID:22043177

  18. Estudo da oxidação parcial do etanol em catalisadores de Rh por DRIFTS

    Directory of Open Access Journals (Sweden)

    Raquel Lima Oliveira

    2013-01-01

    Full Text Available The partial oxidation of ethanol on γ-Al2O3, CeO2, ZrO2 and Ce xZr1-xO2 supported rhodium catalysts was investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS. The catalysts were characterized by temperature-programmed reduction (TPR and cyclohexane dehydrogenation. DRIFTS studies on the partial oxidation of ethanol showed that ethanol is adsorbed dissociatively, through O-H bond breaking, with the formation of ethoxy species, followed by successive dehydrogenation to acetaldehyde and acetyl species. Further oxidation to acetate and carbonate species lead to the formation of CO, CH4 and H2 by decomposition. The presence of CeO2 in the catalysts favored the oxidation steps due to its oxygen storage capacity.

  19. Influence of Gold on Ce-Zr-Co Fluorite-Type Mixed Oxide Catalysts for Ethanol Steam Reforming

    Directory of Open Access Journals (Sweden)

    Véronique Pitchon

    2012-02-01

    Full Text Available The effect of gold presence on carbon monoxide oxidation and ethanol steam reforming catalytic behavior of two Ce-Zr-Co mixed oxides catalysts with a constant Co charge and different Ce/Zr ratios was investigated. The Ce-Zr-Co mixed oxides were obtained by the pseudo sol-gel like method, based on metallic propionates polymerization and thermal decomposition, whereas the gold-supported Ce-Zr-Co mixed oxides catalysts were prepared using the direct anionic exchange. The catalysts were characterized using XRD, TPR, and EDXS-TEM. The presence of Au in doped Ce-Zr-Co oxide catalyst decreases the temperature necessary to reduce the cobalt and the cerium loaded in the catalyst and favors a different reaction pathway, improving the acetaldehyde route by ethanol dehydrogenation, instead of the ethylene route by ethanol dehydration or methane re-adsorption, thus increasing the catalytic activity and selectivity into hydrogen.

  20. Estudo da oxidação parcial do etanol em catalisadores de Rh por DRIFTS A DRIFTS study of the partial oxidation of ethanol on Rh catalysts

    Directory of Open Access Journals (Sweden)

    Raquel Lima Oliveira

    2013-01-01

    Full Text Available The partial oxidation of ethanol on γ-Al2O3, CeO2, ZrO2 and Ce xZr1-xO2 supported rhodium catalysts was investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS. The catalysts were characterized by temperature-programmed reduction (TPR and cyclohexane dehydrogenation. DRIFTS studies on the partial oxidation of ethanol showed that ethanol is adsorbed dissociatively, through O-H bond breaking, with the formation of ethoxy species, followed by successive dehydrogenation to acetaldehyde and acetyl species. Further oxidation to acetate and carbonate species lead to the formation of CO, CH4 and H2 by decomposition. The presence of CeO2 in the catalysts favored the oxidation steps due to its oxygen storage capacity.

  1. Chemical constituents from red algae Bostrychia radicans (Rhodomelaceae): new amides and phenolic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Ana Ligia Leandrini de; Silva, Denise B. da; Lopes, Norberto P.; Debonsi, Hosana M. [Universidade de Sao Paulo (FCFRP/USP), Ribeirao Preto, SP (Brazil). Fac. de Ciencias Farmaceuticas de Ribeirao Preto. Dept. de Quimica e Fisica; Yokoya, Nair S., E-mail: hosana@fcfrp.usp.br [Instituto de Botanica, Sao Paulo, SP (Brazil). Secao de Ficologia

    2012-07-01

    This study describes the isolation and structural determination of two amides, isolated for the first time: N,4-dihydroxy-N-(2'-hydroxyethyl)-benzamide (0.019%) and N,4-dihydroxy-N-(2'-hydroxyethyl)-benzeneacetamide (0.023%). These amides, produced by the red macroalgae Bostrychia radicans, had their structures assigned by NMR spectral data and MS analyses. In addition, this chemical study led to the isolation of cholesterol, heptadecane, squalene, trans-phytol, neophytadiene, tetradecanoic and hexadecanoic acids, methyl hexadecanoate and methyl 9-octadecenoate, 4-(methoxymethyl)-phenol, 4-hydroxybenzaldehyde, methyl 4-hydroxybenzeneacetate, methyl 2-hydroxy-3-(4-hydroxyphenyl)-propanoate, hydroquinone, methyl 4-hydroxymandelate, methyl 4-hydroxybenzoate, 4-hydroxybenzeneacetic acid and (4-hydroxyphenyl)-oxo-acetaldehyde. This is the first report concerning these compounds in B. radicans, contributing by illustrating the chemical diversity within the Rhodomelaceae family. (author)

  2. DNA adducts-chemical addons

    Directory of Open Access Journals (Sweden)

    T R Rajalakshmi

    2015-01-01

    Full Text Available DNA adduct is a piece of DNA covalently bond to a chemical (safrole, benzopyrenediol epoxide, acetaldehyde. This process could be the start of a cancerous cell. When a chemical binds to DNA, it gets damaged resulting in abnormal replication. This could be the start of a mutation and without proper DNA repair, this can lead to cancer. It is this chemical that binds with the DNA is our prime area of concern. Instead of performing the whole body analysis for diagnosing cancer, this test could be carried out for early detection of cancer. When scanning tunneling microscope is used, the DNA results can be obtained earlier. DNA adducts in scientific experiments are used as biomarkers.

  3. DNA adducts-chemical addons

    Science.gov (United States)

    Rajalakshmi, T. R.; AravindhaBabu, N.; Shanmugam, K. T.; Masthan, K. M. K.

    2015-01-01

    DNA adduct is a piece of DNA covalently bond to a chemical (safrole, benzopyrenediol epoxide, acetaldehyde). This process could be the start of a cancerous cell. When a chemical binds to DNA, it gets damaged resulting in abnormal replication. This could be the start of a mutation and without proper DNA repair, this can lead to cancer. It is this chemical that binds with the DNA is our prime area of concern. Instead of performing the whole body analysis for diagnosing cancer, this test could be carried out for early detection of cancer. When scanning tunneling microscope is used, the DNA results can be obtained earlier. DNA adducts in scientific experiments are used as biomarkers. PMID:26015708

  4. Oxidative dehydration of glycerol to acrylic acid over vanadium-impregnated zeolite beta

    International Nuclear Information System (INIS)

    The oxidative dehydration of glycerol to acrylic acid was studied over vanadium-impregnated zeolite Beta. Catalysts were prepared by wet impregnation of ammonium metavanadate over ammonium-exchanged zeolite Beta, followed by air calcination at 823 K. Impregnation reduced the specific surface area, but did not significantly affected the acidity (Bronsted and Lewis) of the zeolites. The catalytic evaluation was carried out in a fixed bed flow reactor using air as the carrier and injecting glycerol by means of a syringe pump. Acrolein was the main product, with acetaldehyde and hydroxy-acetone (acetol) being also formed. Acrylic acid was formed with approximately 25% selectivity at 548 K over the impregnated zeolites. The result can be explained by XPS (X-ray photoelectron spectroscopy) measurements, which indicated a good dispersion of the vanadium inside the pores. (author)

  5. Blood viscosity: influence of erythrocyte deformation.

    Science.gov (United States)

    Chien, S; Usami, S; Dellenback, R J; Gregersen, M I

    1967-08-18

    Suspensions of canine and human erythocytes hardened with acetaldehyde differ from the suspensions of normal erythrocytes with respect to their rheological behavior. Normal erythrocytes can be packed by centrifugation so that the sediment volume is nearly 100 percent cells, but the hardened erythrocytes (RBC's) can be packed only to approximately 60 percent cells. At the same cell percentage the viscosity of the hardened RBC suspension is higher than that of the suspension of normal erythocytes. An increase in shear stress deforms the normal erythocytes and lowers the suspension viscosity, but has no influence on the viscosity of the hardened cell suspension. In blood with high cell percentages, the shear deformation of normal RBC's plays an important role in reducing viscosity and facilitating flow at high shear stresses. PMID:17842793

  6. TiO{sub 2} (B) nanosheets mediate phase selective synthesis of TiO{sub 2} nanostructured photocatalyst

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yuxi; Wang, Changhua; Zhang, Xintong, E-mail: xtzhang@nenu.edu.cn; Sun, Panpan; Kong, Lina; Wei, Yongan; Zheng, Han; Liu, Yichun

    2014-02-15

    Phase selective synthesis is particularly valuable in revealing performance of photocatalyst existing as several polymorphic phases. In this work, we develop a general soft chemical route that used a TiO{sub 2} (B) nanosheet as a precursor to synthesize TiO{sub 2} nanostructures of desired phase. Benefiting from the structural similarity and ultrathin thickness feature, TiO{sub 2} (B) nanosheet precursor can readily transform to pure phase of anatase, rutile and brookite as well as mixed phase of brookite/anatase. A possible dissolution-recrystallization mechanism is proposed for the phase transition of TiO{sub 2} (B) nanosheets to other phases. Photocatalytic activity tests demonstrated that the brookite/anatase mixture had the highest activity in degrading acetaldehyde under UV light irradiation, due to the synergistic effect of high crystallinity, large surface area and mixed phase structure.

  7. Heterologous expression of the Aspergillus nidulans alcR-alcA system in Aspergillus niger.

    Science.gov (United States)

    Nikolaev, I; Mathieu, M; van de Vondervoort, P; Visser, J; Felenbok, B

    2002-10-01

    The inducible and strongly expressed alcA gene encoding alcohol dehydrogenase I from Aspergillus nidulans was transferred together with the activator gene alcR, in the industrial fungus Aspergillus niger. This latter organism does not possess an inducible alc system but has an endogenously constitutive lowly expressed alcohol dehydrogenase activity. The overall induced expression of the alcA gene was of the same order in both fungi, as monitored by alcA transcription, alcohol dehydrogenase activity and heterologous expression of the reporter enzyme, beta-glucuronidase. However, important differences in the pattern of alcA regulation were observed between the two fungi. A high basal level of alcA transcription was observed in A. niger resulting in a lower ratio of alcA inducibility. This may be due to higher levels of the physiological inducer of the alc regulon, acetaldehyde, from general metabolism in A. niger which differs from that of A. nidulans.

  8. Elastic and total cross sections for simple biomolecules in the intermediate energy range

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Dhanoj; Naghma, Rahla; Antony, Bobby, E-mail: bka.ism@gmail.com [Atomic and Molecular Physics Lab, Department of Applied Physics, Indian School of Mines, Dhanbad 826004, JH (India)

    2015-09-15

    The elastic and total cross sections for formaldehyde, acetaldehyde, acetone, 2-butanone and formamide are calculated using the spherical complex optical potential formalism in the intermediate energy range from 50 eV to 10 keV. These cross sections find application to various fields like radiation damage and biological sciences. The present results are compared with the available experimental and theoretical data and are found to give excellent agreement. The elastic cross sections reported for most of the targets in the present energy range are done for the first time. The energy dependence of the contribution of ionization and elastic cross section with respect to the total cross section and the correlation of total cross section with polarizability of the molecules are also studied.

  9. Enhanced photocatalytic activity for degrading pollutants of g-C3N4 by promoting oxygen adsorption after H3BO3 modification

    Science.gov (United States)

    Li, Chengming; Raziq, Fazal; Liu, Chong; Li, Zhijun; Sun, Liqun; Jing, Liqiang

    2015-12-01

    The g-C3N4 has been modified by a hydrothermal post treatment with orthoboric acid. It is shown that the surface modification with an appropriate amount of orthoboric acid obviously enhances the surface photovoltage responses of g-C3N4, clearly indicating that the separation of photogenerated charges is greatly improved. This is well responsible for the enhanced photocatalytic activities for degrading representative gas-phase acetaldehyde, and liquid-phase phenol. Moreover, it is demonstrated that the amount of O2 adsorbed on the surfaces of g-C3N4 is greatly increased after H3BO3 modification based on the O2 temperature-programmed desorption curves. It is suggested that the orthoboric acid modification favors O2 adsorption to promote the photogenerated electrons captured for improved photocatalytic activities. This work would provide feasible routes to further improve the photocatalytic performance of semiconductors for degrading pollutants.

  10. Molecularly Imprinted Polymer Nanoparticles for Formaldehyde Sensing with QCM

    Science.gov (United States)

    Hussain, Munawar; Kotova, Kira; Lieberzeit, Peter A.

    2016-01-01

    Herein, we report on molecularly imprinted polymers (MIPs) for detecting formaldehyde vapors in air streams. A copolymer thin film consisting of styrene, methacrylic acid, and ethylene glycol dimethacrylate on quartz crystal microbalance (QCM) yielded a detection limit of 500 ppb formaldehyde in dry air. Surprisingly, these MIPs showed specific behavior when tested against a range of volatile organic compounds (VOCs), such as acetaldehyde, methanol, formic acid, and dichloromethane. Despite thus being a suitable receptor in principle, the MIPs were not useful for measurements at 50% humidity due to surface saturation by water. This was overcome by introducing primary amino groups into the polymer via allyl amine and by changing the coating morphology from thin film to nanoparticles. This led to the same limit of detection (500 ppb) and selectivity as before, but at the real-life conditions of 50% relative humidity. PMID:27376287

  11. Study of compounds emitted during thermo-oxidative decomposition of polyester fabrics

    Directory of Open Access Journals (Sweden)

    Dzięcioł Małgorzata

    2016-03-01

    Full Text Available Compounds emitted during thermo-oxidative decomposition of three commercial polyester fabrics for indoor outfit and decorations (upholstery, curtains were studied. The experiments were carried out in a flow tubular furnace at 600°C in an air atmosphere. During decomposition process the complex mixtures of volatile and solid compounds were emitted. The main volatile products were carbon oxides, benzene, acetaldehyde, vinyl benzoate and acetophe-none. The emitted solid compounds consisted mainly of aromatic carboxylic acids and its derivatives, among which the greatest part took terephthalic acid, monovinyl terephthalate and benzoic acid. The small amounts of polycyclic aromatic hydrocarbons were also emitted. The emission profiles of the tested polyester fabrics were similar. The presence of toxic compounds indicates the possibility of serious hazard for people during fire.

  12. Assessment of Pollutant Spread from a Building Basement with three Ventilation Systems

    CERN Document Server

    Koffi, Juslin

    2010-01-01

    Ventilation aims at providing a sufficient air renewal for ensuring a good indoor air quality (IAQ), yet building energy policies are leading to adapting various ventilation strategies minimising energy losses through air renewal. A recent IAQ evaluation campaign in French dwellings shows important pollution of living spaces by VOCs such as formaldehyde, acetaldehyde or hexanal, particularly in buildings equipped with a garage. Besides, radon emission from soil is a subject of concern in many countries. Several studies are done to understand its release mode and deal with the spread of this carcinogen gas. This paper aims to experimentally assess a contaminant spread from a house basement using mechanical exhaust and balanced ventilation systems, and natural ventilation.

  13. [Classification of alcohol metabolizing enzymes and polymorphisms--specificity in Japanese].

    Science.gov (United States)

    Harada, S

    2001-04-01

    Multiple forms and gene loci of human alcohol dehydrogenase (ADH EC: 1.2.1.3) and aldehyde dehydrogenase (ALDH, EC: 1.2.1.3) in the major pathway of alcohol metabolism have been found and characterized in the last two decades. With the coenzyme NAD, these enzymes catalyze the reversible conversion of organic alcohols to ketones or aldehydes, and aldehyde to acetic acid. The ADH genes are mapped to chromosome 4p21-25, but the ALDH genes are localized at different chromosomes. The cytochrome P450 2E1 (CYP2E1) gene, which is mapped to chromosome 10q24.3-qter contributes also the conversion of ethanol to acetaldehyde. Genetic polymorphisms have been reported in these alcohol metabolizing enzymes. The metabolisms of alcohol and acetaldehyde in liver and blood after drinking alcohol are thought to be influenced by the interactive action of these enzymes. Amongst the five major classes of the ADH subunits (alpha, beta, gamma, pi, chi, sigma), beta and gamma subunits show genetic polymorphisms. Recently a new nomenclature for ALDH genes has been recommend based on divergent evolution and chromosomal mapping. Two major isoforms designated as cytosolic ALDH1 and mitochondrial ALDH2 can be distinguished by their electrophoretic and kinetic properties as well as by their subcellular localization. Mitochondrial ALDH2 is a major enzyme in the oxidation of acetaldehyde derived from ethanol metabolism. The catalytic deficiency of ALDH2 isozyme is responsible for flushing and other vasomotor symptoms caused by higher acetaldehyde levels after alcohol intake. So far, frequencies of the two alleles of ALDH2 in Mongoloid have been reported in the different population groups. The catalytic deficiency of ALDH2 is caused by a structural point mutation at amino acid position 487, where a substitution of Glu to Lys resulting from a transition of G (C) to A (T) at 1510 nucleotide from the initiation codon has occurred. Individuals deficient in ALDH2 activity refrain from excessive drinking

  14. A DRIFTS study of the partial oxidation of ethanol on Rh catalysts; Estudo da oxidacao parcial do etanol em catalisadores de Rh por DRIFTS

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Raquel Lima; Passos, Fabio Barboza, E-mail: fbpassos@vm.uff.br [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Departamento de Engenharia Quimica e de Petroleo

    2013-09-01

    The partial oxidation of ethanol on {gamma}-Al{sub 2}O{sub 3}, CeO{sub 2}, ZrO{sub 2} and Ce{sub x}Zr{sub 1-x}O{sub 2} supported rhodium catalysts was investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). The catalysts were characterized by temperature-programmed reduction (TPR) and cyclohexane dehydrogenation. DRIFTS studies on the partial oxidation of ethanol showed that ethanol is adsorbed dissociatively, through O-H bond breaking, with the formation of ethoxy species, followed by successive dehydrogenation to acetaldehyde and acetyl species. Further oxidation to acetate and carbonate species lead to the formation of CO, CH{sub 4} and H{sub 2} by decomposition. The presence of CeO{sub 2} in the catalysts favored the oxidation steps due to its oxygen storage capacity. (author)

  15. Low-temperature steam-reforming of ethanol over ZnO-supported Ni and Cu catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Homs, Narcis; Llorca, Jordi; De la Piscina, Pilar Ramirez [Departament de Quimica Inorganica, Universitat de Barcelona, C/Marti i Franques 1-11, 08028 Barcelona (Spain)

    2006-08-15

    ZnO-supported Ni and Cu as well as bimetallic Co-Ni and Co-Cu catalysts containing ca. 0.7wt% sodium promoter and prepared by the co-precipitation method were tested in the ethanol steam-reforming reaction at low temperature (523-723K), using a bioethanol-like mixture diluted in Ar. Monometallic ZnO-supported Cu or Ni samples do not exhibit good catalytic performance in the steam-reforming of ethanol for hydrogen production. Copper catalyst mainly dehydrogenates ethanol to acetaldehyde, whereas nickel catalyst favours ethanol decomposition. However, the addition of Ni to ZnO-supported cobalt has a positive effect both on the production of hydrogen at low temperature (<573K), and on catalyst stability. Evidence for alloy formation as well as mixed oxides at the microstructural level was found in the bimetallic systems after running the ethanol steam-reforming reaction by HRTEM-EELS. (author)

  16. A Doubles Correction to Electronic Excited States from Configuration Interaction in the Space of Single Substitutions

    Science.gov (United States)

    Head-Gordon, Martin; Rico, Rudolph J.; Lee, Timothy J.; Oumi, Manabu

    1994-01-01

    A perturbative correction to the method of configuration interaction with single substitutions (CIS) is presented. This CIS(D) correction approximately introduces the effect of double substitutions which are absent in CIS excited states. CIS(D) is a second-order perturbation expansion of the coupled-cluster excited state method, restricted to single and double substitutions, in a series in which CIS is zeroth order, and the first-order correction vanishes. CIS (D) excitation energies are size consistent and the calculational complexity scales with the fifth power of molecular size, akin to second-order Moller-Plesset theory for the ground state. Calculations on singlet excited states of ethylene, formaldehyde, acetaldehyde, butadiene and benzene show that CIS (D) is a uniform improvement over CIS. CIS(D) appears to be a promising method for examining excited states of large molecules, where more accurate methods are not feasible.

  17. Alcoholic cirrhosis and hepatocellular carcinoma.

    Science.gov (United States)

    Stickel, Felix

    2015-01-01

    Hepatocellular carcinoma shows a rising incidence worldwide, and the largest burden of disease in Western countries derives from patients with alcoholic liver disease (ALD) and cirrhosis, the latter being the premier premalignant factor for HCC. The present chapter addresses key issues including the epidemiology of alcohol-associated HCC, and its link to other coexisting non-alcoholic liver diseases, and additional host and environmental risk factors including the underlying genetics. Also discussed are molecular mechanisms of alcohol-associated liver cancer evolution involving the mediators of alcohol toxicity and carcinogenicity, acetaldehyde and reactive oxygen species, as well as the recently described mutagenic adducts which these mediators form with DNA. Specifically, interference of alcohol with retinoids and cofactors of transmethylation processes are outlined. Information presented in this chapter illustrates that the development of HCC in the context of ALD is multifaceted and suggests several molecular targets for prevention and markers for the screening of risk groups. PMID:25427904

  18. Effect of calcination temperature on the photocatalytic properties of electrospun TiO2 nanofibers.

    Science.gov (United States)

    Lee, Young-In; Lee, Jong-Sik; Park, Eun-Sil; Jang, Dae-Hwan; Lee, Jae-Eun; Kim, Kahee; Myung, Nosang V; Choa, Yong-Ho

    2014-10-01

    In this study, TiO2 nanofibers with a high aspect ratio and a large specific surface area were synthesized using the electrospinning technique, and the effect of calcination temperature on their crystal structure, diameter, specific surface area and photocatalytic activity was systematically investigated. The electrospun, as-prepared PVP/TTIP nanofibers were several tens of micrometers in length with a diameter of 74 nm. TiO2 nanofibers with an average diameter of 50 nm were prepared after calcination at various temperatures. The calcination temperature significantly influenced the photocatalytic and material properties of TiO2 including grain size and specific surface area. When compared to other nanostructured TiO2 materials, such as commercial TiO2 nanoparticles (P25, Degussa), the TiO2 nanofibers exhibited greater photocatalytic activity for the degradation of acetaldehyde and ammonia. PMID:25942911

  19. Sublethal Concentrations of Antibiotics Cause Shift to Anaerobic Metabolism in Listeria monocytogenes and Induce Phenotypes Linked to Antibiotic Tolerance

    DEFF Research Database (Denmark)

    Knudsen, Gitte Maegaard; Fromberg, Arvid; Ng, Yin;

    2016-01-01

    antibiotic concentrations would affect the bacterial physiology and induce antibiotic tolerance. Transcriptomic analyses demonstrated that each of the four antibiotics tested caused an antibiotic-specific gene expression pattern related to mode-of-action of the particular antibiotic. All four antibiotics...... caused the same changes in expression of several metabolic genes indicating a shift from aerobic to anaerobic metabolism and higher ethanol production. A mutant in the bifunctional acetaldehyde-CoA/alcohol dehydrogenase encoded by Imo1634 did not have altered antibiotic tolerance. However, a mutant...... in Imo1179 (eutE) encoding an aldehyde oxidoreductase where rerouting caused increased ethanol production was tolerant to three of four antibiotics tested. This shift in metabolism could be a survival strategy in response to antibiotics to avoid generation of ROS production from respiration by oxidation...

  20. Mutations Closer to the Active Site Improve the Promiscuous Aldolase Activity of 4-Oxalocrotonate Tautomerase More Effectively than Distant Mutations.

    Science.gov (United States)

    Rahimi, Mehran; van der Meer, Jan-Ytzen; Geertsema, Edzard M; Poddar, Harshwardhan; Baas, Bert-Jan; Poelarends, Gerrit J

    2016-07-01

    The enzyme 4-oxalocrotonate tautomerase (4-OT), which catalyzes enol-keto tautomerization as part of a degradative pathway for aromatic hydrocarbons, promiscuously catalyzes various carbon-carbon bond-forming reactions. These include the aldol condensation of acetaldehyde with benzaldehyde to yield cinnamaldehyde. Here, we demonstrate that 4-OT can be engineered into a more efficient aldolase for this condensation reaction, with a >5000-fold improvement in catalytic efficiency (kcat /Km ) and a >10(7) -fold change in reaction specificity, by exploring small libraries in which only "hotspots" are varied. The hotspots were identified by systematic mutagenesis (covering each residue), followed by a screen for single mutations that give a strong improvement in the desired aldolase activity. All beneficial mutations were near the active site of 4-OT, thus underpinning the notion that new catalytic activities of a promiscuous enzyme are more effectively enhanced by mutations close to the active site. PMID:27238293

  1. Ethanol consumption as inductor of pancreatitis

    Institute of Scientific and Technical Information of China (English)

    José; A; Tapia; Ginés; M; Salido; Antonio; González

    2010-01-01

    Alcohol abuse is a major cause of pancreatitis, a condition that can manifest as both acute necroinflammation and chronic damage (acinar atrophy and f ibrosis). Pancreatic acinar cells can metabolize ethanol via the oxidative pathway, which generates acetaldehyde and involves the enzymes alcohol dehydrogenase and possibly cytochrome P4502E1. Additionally, ethanol can be metabolized via a nonoxidative pathway involving fatty acid ethyl ester synthases. Metabolism of ethanol by acinar and other pancreatic cells and the consequent generation of toxic metabolites, are postulated to play an important role in the development of alcohol-related acute and chronic pancreatic injury. This current work will review some recent advances in the knowledge about ethanol actions on the exocrine pancreas and its relationship to inflammatory disease and cancer.

  2. Use of a flor velum yeast for modulating colour, ethanol and major aroma compound contents in red wine.

    Science.gov (United States)

    Moreno, Juan; Moreno-García, Jaime; López-Muñoz, Beatriz; Mauricio, Juan Carlos; García-Martínez, Teresa

    2016-12-15

    The most important and negative effect of the global warming for winemakers in warm and sunny regions is the observed lag between industrial and phenolic grape ripeness, so only it is possible to obtain an acceptable colour when the ethanol content of wine is high. By contrast, the actual market trends are to low ethanol content wines. Flor yeast growing a short time under velum conditions, decreases the ethanol and volatile acidity contents, has a favorable effect on the colour and astringency and significantly changes the wine content in 1-propanol, isobutanol, acetaldehyde, 1,1-diethoxiethane and ethyl lactate. The Principal Component Analysis of six enological parameters or five aroma compounds allows to classify the wines subjected to different velum formation conditions. The obtained results in two tasting sessions suggest that the flor yeast helps to modulate the ethanol, astringency and colour and supports a new biotechnological perspective for red winemakers. PMID:27451159

  3. Natural Products for the Prevention and Treatment of Hangover and Alcohol Use Disorder.

    Science.gov (United States)

    Wang, Fang; Li, Ya; Zhang, Yu-Jie; Zhou, Yue; Li, Sha; Li, Hua-Bin

    2016-01-07

    Alcoholic beverages such as beer, wine and spirits are widely consumed around the world. However, alcohol and its metabolite acetaldehyde are toxic and harmful to human beings. Chronic alcohol use disorder or occasional binge drinking can cause a wide range of health problems, such as hangover, liver damage and cancer. Some natural products such as traditional herbs, fruits, and vegetables might be potential dietary supplements or medicinal products for the prevention and treatment of the problems caused by excessive alcohol consumption. The aim of this review is to provide an overview of effective natural products for the prevention and treatment of hangover and alcohol use disorder, and special emphasis is paid to the possible functional component(s) and related mechanism(s) of action.

  4. Coupling of Nanocrystalline Anatase TiO2 to Porous Nanosized LaFeO3 for Efficient Visible-Light Photocatalytic Degradation of Pollutants

    Directory of Open Access Journals (Sweden)

    Muhammad Humayun

    2016-01-01

    Full Text Available In this work we have successfully fabricated nanocrystalline anatase TiO2/perovskite-type porous nanosized LaFeO3 (T/P-LFO nanocomposites using a simple wet chemical method. It is clearly demonstrated by means of atmosphere-controlled steady-state surface photovoltage spectroscopy (SPS responses, photoluminescence spectra, and fluorescence spectra related to the formed OH− radical amount that the photogenerated charge carriers in the resultant T/P-LFO nanocomposites with a proper mole ratio percentage of TiO2 display much higher separation in comparison to the P-LFO alone. This is highly responsible for the improved visible-light activities of T/P-LFO nanocomposites for photocatalytic degradation of gas-phase acetaldehyde and liquid-phase phenol. This work will provide a feasible route to synthesize visible-light responsive nano-photocatalysts for efficient solar energy utilization.

  5. Rapid Monitoring of Mercury in Air from an Organic Chemical Factory in China Using a Portable Mercury Analyzer

    Directory of Open Access Journals (Sweden)

    Akira Yasutake

    2011-01-01

    Full Text Available A chemical factory, using a production technology of acetaldehyde with mercury catalysis, was located southeast of Qingzhen City in Guizhou Province, China. Previous research showed heavy mercury pollution through an extensive downstream area. A current investigation of the mercury distribution in ambient air, soils, and plants suggests that mobile mercury species in soils created elevated mercury concentrations in ambient air and vegetation. Mercury concentrations of up to 600 ng/m3 in air over the contaminated area provided evidence of the mercury transformation to volatile Hg(0. Mercury analysis of soil and plant samples demonstrated that the mercury concentrations in soil with vaporized and plant-absorbable forms were higher in the southern area, which was closer to the factory. Our results suggest that air monitoring using a portable mercury analyzer can be a convenient and useful method for the rapid detection and mapping of mercury pollution in advanced field surveys.

  6. Oxidative dehydration of glycerol to acrylic acid over vanadium-impregnated zeolite beta

    Energy Technology Data Exchange (ETDEWEB)

    Pestana, Carolina F.M.; Guerra, Antonio C.O.; Turci, Cassia C. [Universidade Federal do Rio de Janeiro, RJ (Brazil). Inst. de Quimica; Ferreira, Glaucio B. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Quimica; Mota, Claudio J.A., E-mail: cmota@iq.ufrj.br [INCT Energia e Ambiente, Universidade Federal do Rio de Janeiro, RJ (Brazil)

    2013-01-15

    The oxidative dehydration of glycerol to acrylic acid was studied over vanadium-impregnated zeolite Beta. Catalysts were prepared by wet impregnation of ammonium metavanadate over ammonium-exchanged zeolite Beta, followed by air calcination at 823 K. Impregnation reduced the specific surface area, but did not significantly affected the acidity (Bronsted and Lewis) of the zeolites. The catalytic evaluation was carried out in a fixed bed flow reactor using air as the carrier and injecting glycerol by means of a syringe pump. Acrolein was the main product, with acetaldehyde and hydroxy-acetone (acetol) being also formed. Acrylic acid was formed with approximately 25% selectivity at 548 K over the impregnated zeolites. The result can be explained by XPS (X-ray photoelectron spectroscopy) measurements, which indicated a good dispersion of the vanadium inside the pores. (author)

  7. Biosynthesis of indole-3-acetic acid via the indole-3-acetamide pathway in Streptomyces spp.

    Science.gov (United States)

    Manulis, S; Shafrir, H; Epstein, E; Lichter, A; Barash, I

    1994-05-01

    Various Streptomyces spp. including S. violaceus, S. scabies, S. griseus, S. exfoliatus, S. coelicolor and S. lividans secrete indole-3-acetic acid (IAA) when fed with L-tryptophan (Trp). Production of IAA was detected in Streptomyces strains causing potato scab as well as in non-pathogenic strains. The pathways for IAA synthesis from Trp were investigated in S. violaceus and S. exfoliatus. Indole-3-acetamide (IAM), indole-3-lactic acid (ILA), indole-3-ethanol (IEt) and IAA were identified by HPLC and GC-MS. Streptomyces cells were capable of catabolizing IAM, ILA, IEt and indole-3-acetaldehyde (IAAId) into IAA. Incorporation of radioactivity into IAM, IAA and ILA but not IEt was detected when cells were fed with L-[3-14C]tryptophan. Results indicate the presence of the IAM pathway (Trp-->IAM-->IAA) and the possible presence of additional pathways for IAA biosynthesis in Streptomyces. PMID:8025670

  8. Electrocatalytic activity of ZnS nanoparticles in direct ethanol fuel cells

    Science.gov (United States)

    Bredol, Michael; Kaczmarek, Michał; Wiemhöfer, Hans-Dieter

    2014-06-01

    Low temperature fuel cells consuming ethanol without reformation would be a major step toward the use of renewable energy sources from biomass. However, the necessary electrodes and electrocatalysts still are far from being perfect and suffer from various poisoning and deactivation processes. This work describes investigations on systems using carbon/ZnS-based electrocatalysts for ethanol oxidation in complete membrane electrode assemblies (MEAs). MEAs were built on Nafion membranes with active masses prepared from ZnS nanoparticles and Vulcan carbon support. Under operation, acetic acid and acetaldehyde were identified and quantified as soluble oxidation products, whereas the amount of CO2 generated could not be quantified directly. Overall conversion efficiencies of up to 25% were estimated from cells operated over prolonged time. From polarization curves, interrupt experiments and analysis of reaction products, mass transport problems (concentration polarization) and breakthrough losses were found to be the main deficiencies of the ethanol oxidation electrodes fabricated so far.

  9. Photodissociation of CH3CHO at 248 nm by time-resolved Fourier-transform infrared emission spectroscopy: Verification of roaming and triple fragmentation

    Science.gov (United States)

    Hung, Kai-Chan; Tsai, Po-Yu; Li, Hou-Kuan; Lin, King-Chuen

    2014-02-01

    By using time-resolved Fourier-transform infrared emission spectroscopy, the HCO fragment dissociated from acetaldehyde (CH3CHO) at 248 nm is found to partially decompose to H and CO. The fragment yields are enhanced by the Ar addition that facilitates the collision-induced internal conversion. The channels to CH2CO + H2 and CH3CO + H are not detected significantly. The rotational population distribution of CO, after removing the Ar collision effect, shows a bimodal feature comprising both low- and high-rotational (J) components, sharing a fraction of 19% and 81%, respectively, for the vibrational state v = 1. The low-J component is ascribed to both roaming pathway and triple fragmentation. They are determined to have a branching ratio of 0.06, respectively, relative to the whole v = 1 population. The CO roaming is accompanied by a highly vibrational population of CH4 that yields a vibrational bimodality.

  10. On a hypothetical generational relationship between HCN and constituents of the reductive citric acid cycle.

    Science.gov (United States)

    Eschenmoser, Albert

    2007-04-01

    Encouraged by observations made on the course of reactions the HCN-tetramer can undergo with acetaldehyde, I delineate a constitutional and potentially generational relationship between HCN and those constituents of the reductive citric acid cycle that are direct precursors of amino acids in contemporary metabolism. In this context, the robustness postulate of classical prebiotic chemistry is questioned, and, by an analysis of the (hypothetical) reaction-tree of a stepwise hydrolysis of the HCN-tetramer, it is shown how such a non-robust chemical reaction platform could harbor the potential for the emergence of autocatalytic cycles. It is concluded that the chemistry of HCN should be revisited by focussing on its non-robust parts in order to demonstrate its full potential as one of the possible roots of prebiotic self-organizing chemical processes.

  11. [Study of the effect of volatile metabolites of Trichoderma hamatum on the growth of phytopathogenic soilborne fungi.].

    Science.gov (United States)

    Dal Bello, G M; Mónaco, C I; Cháves, A R

    1997-09-01

    Volatile compounds produced by Trichoderma hamatum were tested for their capacity to suppress in vitro the growth of Alternaria citri, Bipolaris cynodontis, Bipolaris sorokiniana, Curvularia brachyspora, Curvularia lunata, Curvularia oryzae-sativae, Drechslera tritici-repentis, Rhizoctonia solani, Sclerotinia minor and Sclerotium rolfsii. The organisms were cultured in an apparatus made with two Erlenmeyer flasks assembled by their top parts. With the aid of the gas chromatographic technique the variation of carbon dioxide, oxygen and ethylene in the internal system was determined. Acetaldehyde and ethanol were not found. Due to the respiratory metabolism of T. hamatum the carbon dioxide level progressively increased while the oxygen content decreased. Ethylene production was low and after three days remained constant. Excepting C. oryzae-sativae and B. cynodontis the other species showed changes in the growth and development. These results suggest the inhibitory volatiles of T. hamatum as one possible mechanism of biological control.

  12. Spectral signatures for RDX-based explosives in the 3 micron region

    Science.gov (United States)

    Osborn, Tabetha; Kaimal, Sindhu; Reeve, Scott W.; Burns, William

    2008-04-01

    Explosive compounds such as RDX, and HMX present significant challenges to optically based sensors. This difficulty is due in part to the low vapor pressures these compounds possess. One approach for sensing explosives that circumvents the low explosive vapor pressure problem, involves focusing on the trace amounts of relatively high vapor pressure impurities that will be present in the vapor signature. In order to effectively detect these volatile impurities, the spectral signature databases must be readily available. One of our goals therefore, is the generation of a database of high resolution spectral signatures for these volatile organic impurities. Some rather formidable spectroscopic measurement challenges have been encountered while working to extend the spectral signature effort to the 3 micron region. Here we will outline progress to date, with a focus on the volatile organic compounds formaldehyde, acetaldehyde, nitromethane, acetone, isobutene, and cyclohexanone.

  13. Acidity-controlled selective oxidation of alpha-pinene, isolated from Indonesian pine's turpentine oils (pinus merkusii)

    Science.gov (United States)

    Masruri; Farid Rahman, Mohamad; Nurkam Ramadhan, Bagus

    2016-02-01

    Alpha-pinene was isolated in high purity from turpentine oil harvested from Pinus merkusii plantation. The recent investigation on selective oxidation of alpha-pinene using potassium permanganate was undertaken under acidic conditions. The result taught the selective oxidation of alpha-pinene in acidic using potassium permanganate lead to the formation of 2-(3-acetyl-2,2-dimethylcyclobutyl)acetaldehyde or pinon aldehyde. The study method applied reaction in various different buffer conditions i.e. pH 3, 4, 5, and 6, respectively, and each reaction product was monitored using TLC every hour. Product determination was undertaken on spectrometry basis such as infrared, ultra violet-visible, gas chromatography- and liquid chromatography-mass spectrometry.

  14. The census of complex organic molecules in the solar type protostar IRAS16293-2422

    CERN Document Server

    Jaber, Ali A; Kahane, C; Caux, E

    2014-01-01

    Complex Organic Molecules (COMs) are considered crucial molecules, since they are connected with organic chemistry, at the basis of the terrestrial life. More pragmatically, they are molecules in principle difficult to synthetize in the harsh interstellar environments and, therefore, a crucial test for astrochemical models. Current models assume that several COMs are synthesised on the lukewarm grain surfaces ($\\gtrsim$30-40 K), and released in the gas phase at dust temperatures $\\gtrsim$100 K. However, recent detections of COMs in $\\lesssim$20 K gas demonstrate that we still need important pieces to complete the puzzle of the COMs formation. We present here a complete census of the oxygen and nitrogen bearing COMs, previously detected in different ISM regions, towards the solar type protostar IRAS16293-2422. The census was obtained from the millimeter-submillimeter unbiased spectral survey TIMASSS. Six COMs, out of the 29 searched for, were detected: methyl cyanide, ketene, acetaldehyde, formamide, dimethyl ...

  15. Bioethanol Production Optimization: A Thermodynamic Analysis

    Science.gov (United States)

    Álvarez, Víctor H.; Rivera, Elmer Ccopa; Costa, Aline C.; Filho, Rubens Maciel; Maciel, Maria Regina Wolf; Aznar, Martín

    In this work, the phase equilibrium of binary mixtures for bioethanol production by continuous extractive process was studied. The process is composed of four interlinked units: fermentor, centrifuge, cell treatment unit, and flash vessel (ethanol-congener separation unit). A proposal for modeling the vapor-liquid equilibrium in binary mixtures found in the flash vessel has been considered. This approach uses the Predictive Soave-Redlich-Kwong equation of state, with original and modified molecular parameters. The congeners considered were acetic acid, acetaldehyde, furfural, methanol, and 1-pentanol. The results show that the introduction of new molecular parameters r and q in the UNIFAC model gives more accurate predictions for the concentration of the congener in the gas phase for binary and ternary systems.

  16. Fermentative capabilities and volatile compounds produced by Kloeckera/Hanseniaspora and Saccharomyces yeast strains in pure and mixed cultures during Agave tequilana juice fermentation.

    Science.gov (United States)

    González-Robles, Ivonne Wendolyne; Estarrón-Espinosa, Mirna; Díaz-Montaño, Dulce María

    2015-09-01

    The fermentative and aromatic capabilities of Kloeckera africana/Hanseniaspora vineae K1, K. apiculata/H. uvarum K2, and Saccharomyces cerevisiae S1 and S2 were studied in pure and mixed culture fermentations using Agave tequila juice as the culture medium. In pure and mixed cultures, Kloeckera/Hanseniaspora strains showed limited growth and sugar consumption, as well as low ethanol yield and productivity, compared to S. cerevisiae, which yielded more biomass, ethanol and viable cell concentrations. In pure and mixed cultures, S. cerevisiae presented a similar behaviour reaching high biomass production, completely consuming the sugar, leading to high ethanol production. Furthermore, the presence of S. cerevisiae strains in the mixed cultures promoted the production of higher alcohols, acetaldehyde and ethyl esters, whereas Kloeckera/Hanseniaspora strains stimulated the production of ethyl acetate and 2-phenyl ethyl acetate compounds. PMID:26108494

  17. Matrix isolation investigation of the ozonolysis of propene

    Science.gov (United States)

    Coleman, Bridgett E.; Ault, Bruce S.

    2010-07-01

    The matrix isolation technique, combined with infrared spectroscopy and merged jet deposition of ozone with propene led to the observation of "later", more stable products of this ozonolysis reaction. The observed products, specifically formaldehyde and acetaldehyde, are precisely the products predicted by the Criegee mechanism, formed by the two fragmentation pathways from the initial primary ozonide. Hence, the merged jet results strongly support the Criegee mechanism. In contrast, twin jet codeposition experiments followed by annealing led to no visible changes in the spectra. Subsequent irradiation of these twin jet matrices involving ozone with light of λ ⩾ 220 nm led to O atom production and subsequent reaction with propene. Multiple products were observed in these photochemical experiments. Extensive 18O isotopic labeling experiments, comparisons with literature spectra, and detailed theoretical calculations at the B3LYP/6-311++G(d,2p) level provided important supporting data.

  18. Research into aroma changes in irradiated foodstuffs. I.- Studies on Fish; Investigacion de Alteraciones de Aroma en alimentos irradiados. I Estudio sobre Pescado

    Energy Technology Data Exchange (ETDEWEB)

    Barreiro Pinero, R.; Gasco Sanchez, L.; Valverde Garcia, F.

    1972-07-01

    Radiolytic formation of volatile compounds have been investigated in fillets of hake, codfish and bonito gamma-irradiated at a dose range of 0.1-5 Mrads. Analytical methods have been developed by gas chromatography of functional group derivatives: carbonyls as 2,4,-dinitrophenyl hydrazones, primary and secondary amines as N-alkyl benzamides, and thiols as 2,4-dinitrophenyl alkyl thioethers. The main results are as follows: increasing with the integral dose of the whole carbonyls, the most significant components being acetaldehyde, propional dehyde and formaldehyde; no significant variations with the integral dose od the traces of ammonia, methylamine, trimethylamine, ethylamine, diethylamine, propylamine, butylamine and pentylamine found in unirradiated samples; and radiolytic formation of methanethiol and dimethyl disulfide. (Author) 98 refs.

  19. Comparison of the impact of the Tobacco Heating System 2.2 and a cigarette on indoor air quality.

    Science.gov (United States)

    Mitova, Maya I; Campelos, Pedro B; Goujon-Ginglinger, Catherine G; Maeder, Serge; Mottier, Nicolas; Rouget, Emmanuel G R; Tharin, Manuel; Tricker, Anthony R

    2016-10-01

    The impact of the Tobacco Heating System 2.2 (THS 2.2) on indoor air quality was evaluated in an environmentally controlled room using ventilation conditions recommended for simulating "Office", "Residential" and "Hospitality" environments and was compared with smoking a lit-end cigarette (Marlboro Gold) under identical experimental conditions. The concentrations of eighteen indoor air constituents (respirable suspended particles (RSP) Marlboro Gold resulted in greater increases in the concentrations of acetaldehyde (58.8, 83.8 and 33.1 μg/m(3)) and nicotine (34.7, 29.1 and 34.6 μg/m(3)) as well as all other measured indoor air constituents in the "Office", "Residential" and "Hospitality" simulations, respectively. PMID:27311683

  20. [Study of the effect of volatile metabolites of Trichoderma hamatum on the growth of phytopathogenic soilborne fungi.].

    Science.gov (United States)

    Dal Bello, G M; Mónaco, C I; Cháves, A R

    1997-09-01

    Volatile compounds produced by Trichoderma hamatum were tested for their capacity to suppress in vitro the growth of Alternaria citri, Bipolaris cynodontis, Bipolaris sorokiniana, Curvularia brachyspora, Curvularia lunata, Curvularia oryzae-sativae, Drechslera tritici-repentis, Rhizoctonia solani, Sclerotinia minor and Sclerotium rolfsii. The organisms were cultured in an apparatus made with two Erlenmeyer flasks assembled by their top parts. With the aid of the gas chromatographic technique the variation of carbon dioxide, oxygen and ethylene in the internal system was determined. Acetaldehyde and ethanol were not found. Due to the respiratory metabolism of T. hamatum the carbon dioxide level progressively increased while the oxygen content decreased. Ethylene production was low and after three days remained constant. Excepting C. oryzae-sativae and B. cynodontis the other species showed changes in the growth and development. These results suggest the inhibitory volatiles of T. hamatum as one possible mechanism of biological control. PMID:17655390