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Sample records for amyl acetate

  1. Kinetics Studies on Esterification Reaction of Acetic acid with Iso-amyl Alcohol over Ion Exchange Resin as Catalysts

    Directory of Open Access Journals (Sweden)

    Bhaskar D. Kulkarni

    2014-01-01

    Full Text Available The low molecular weight organic esters have pleasing smell and are found in applications in the food industry for synthetic essence and perfume. Esterification reactions are ubiquitous reactions especially in pharmaceutical, perfumery and polymer industries, wherein; both heterogeneous and homogeneous catalysts have been extensively used. Iso-amyl acetate (or Iso-pentyl acetate is often called as banana oil, since it has the recognizable odor of this fruit. Iso-amyl acetate is synthesized by esterification of acetic acid with iso-amyl alcohol. (Eq.1. Since the equilibrium does not help the formation of the ester, it must be shifted to the right, in favor of the product, by using a surplus of one of the starting materials. Iso-amyl acetate is a kind of flavor reagent with fruit taste. The use of H2SO4 often originates the problems such as corrosion for equipments and pollution for environment.

  2. Study on Extraction Performance of Tri-iso-amyl Phosphate

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The distribution performance of HNO3, Pu(Ⅲ ), Pu(Ⅳ) and Np(Ⅳ) in the two phase system of Tri-iso-Amyl Phosphate(TiAP) and aqueous, the influence of the concentration of extractant, nitric acid and Al(NO3)3 on the distribution ratio of Pu(Ⅲ ),

  3. 40 CFR 721.2920 - tert-Amyl peroxy alkylene ester (generic name).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false tert-Amyl peroxy alkylene ester... Specific Chemical Substances § 721.2920 tert-Amyl peroxy alkylene ester (generic name). (a) Chemical... alkylene ester (PMN P-85-1180) is subject to reporting under this section for the significant new...

  4. [Autochthonous yeasts isolated in Tenerife wines and their influence on ethyl acetate and higher alcohol concentrations analyzed by gas chromatography].

    Science.gov (United States)

    Salvadores, M P; Díaz, M E; Cardell, E

    1993-12-01

    A taxonomic study of yeasts present on Tenerife wines, (Tacoronte-Acentejo Specific Denomination) has been carried out. Nine species of the genera: Saccharomyces, Torulaspora, Brettanomyces, Kluyveromyces, Debaryomyces, Saccharomycodes, Hansenula, Pichia and Candida have been isolated. Parallely we analysed volatile compounds of the wines such as ethyl acetate, methanol, isobutanol and amylic alcohols by gas chromatography. Appreciable quantities of ethyl acetate were detected due to the low fermentative power of species such as Candida glabrata and Debaryomyces hansenii. The greatest concentration of amylic alcohols were found in wines containing yeast with high alcohol producing power like Saccharomyces cerevisiae.

  5. IRIS Toxicological Review and Summary Documents for Tertiary Amyl Ethyl Ether (Taee)

    Science.gov (United States)

    This is EPA's first assessment of the noncancer health effects and carcinogenic potential of tertiary amyl ethyl ether (TAEE). The IRIS program is preparing an assessment that will incorporate health effects information available for TAEE, and current risk assessment methods. T...

  6. Near-fatal methemoglobinemia after recreational inhalation of amyl nitrite aerosolized with a compressed gas blower.

    Science.gov (United States)

    Lin, Chih-Hao; Fang, Cheng-Chung; Lee, Chien-Chang; Ko, Patrick Chow-In; Chen, Wen-Jone

    2005-11-01

    Adverse effects associated with recreational inhalation of nitrites are usually mild and rarely life-threatening. We report a rare case of near-fatal methemoglobinemia after inhalation of amyl nitrite after aerosolizing the liquid using a compressed gas blower designed to clean photographic equipment that employed hydrofluoroalkane-134a as a propellant. A 31-year-old previously healthy male became dyspneic and fainted soon after the recreational inhalation of amyl nitrite aerosolized using a compressed gas blower. He was brought to the emergency department with severe cyanotic appearance and profound shock. Oxygen saturation was 82%, unresponsive to oxygen supply. His methemoglobin blood level was 52.2%. After 100 mg of methylene blue (2 mg/kg body weight) was administered intravenously, he recovered consciousness, and dyspnea and cyanosis subsided gradually. This case illustrates the extraordinary hazard of the use of a compressed gas blower in the recreational inhalation of nitrites. Prompt recognition and rapid antidotal treatment may adequately correct near-fatal overdose associated with recreational use of amyl nitrite.

  7. Separation of Acetic Acid from Aqueous Solution using Various Organic Solvents

    Directory of Open Access Journals (Sweden)

    Md. Zaved Hossain Khan

    2014-01-01

    Full Text Available 800x600 Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 In the study a model has been developed to separate the acetic acid from aqueous solution by liquid-liquid extraction and find out the proper solvent for this separation. Various solvents such as n-butanol, iso butanol, amyl alcohol and ethyl acetate are used for separation of acetic acid from water. The binodal curves (mutual solubility curves for acetic acid distributed between water and an organic solvent were obtained by titrating known mixtures of two components (water and solvents with the third component acetic acid to the point of first appearance of permanent turbidity. In order to determine the tie-lines, the absorbance of the coexisting phases, obtained by the separation of ternary mixtures within the binodal curve are needed to be determined. The absorbance of each point had been determined by a UV spectrophotometer. Distribution diagrams are obtained by plotting weight percent of acetic acid in solvent phase against the weight percent of acetic acid in water phase. Selectivity diagrams are also obtained by plotting (wt. % of acetic acid / (percent of acetic acid + percent of water in solvent phase against the same quantity in the diluent phase. The separation factor is determined numerically from the tie-line data.

  8. Screening for occupational vitiligo in workers exposed to hydroquinone monomethyl ether and to paratertiary-amyl-phenol

    Energy Technology Data Exchange (ETDEWEB)

    O' Sullivan, J.J.; Stevenson, C.J.

    1981-11-01

    Two men reported previously with vitiligo after occupational exposure to hydroquinone monomethyl ether (HMME) have been reviewed after eight years. Repigmentation of significant degree was found in one man and of limited degree in the other. One hundred and sixty-nine men in the same works have been screened with Wood's light for evidence of vitiligo. No cases were found in the 148 men exposed to HMME (colleagues who screened 100 men exposed to HMME in two other factories also found no case) or in the 129 who had been exposed to paratertiary-amyl-phenol. Loss of light reflection on Wood's light examination was observed in 13 men due to scars or to other skin disorders.

  9. ETBE (ethyl tert butyl ether) and TAME (tert amyl methyl ether) affect microbial community structure and function in soils.

    Science.gov (United States)

    Bartling, Johanna; Esperschütz, Jürgen; Wilke, Berndt-Michael; Schloter, Michael

    2011-03-15

    Ethyl tert butyl ether (ETBE) and tert amyl methyl ether (TAME) are oxygenates used in gasoline in order to reduce emissions from vehicles. The present study investigated their impact on a soil microflora that never was exposed to any contamination before. Therefore, soil was artificially contaminated and incubated over 6 weeks. Substrate induced respiration (SIR) measurements and phospholipid fatty acid (PLFA) analysis indicated shifts in both, microbial function and structure during incubation. The results showed an activation of microbial respiration in the presence of ETBE and TAME, suggesting biodegradation by the microflora. Furthermore, PLFA concentrations decreased in the presence of ETBE and TAME and Gram-positive bacteria became more dominant in the microbial community.

  10. Obtaining of inulin acetate

    OpenAIRE

    Khusenov, Arslonnazar; Rakhmanberdiev, Gappar; Rakhimov, Dilshod; Khalikov, Muzaffar

    2014-01-01

    In the article first obtained inulin ester inulin acetate, by etherification of inulin with acetic anhydride has been exposed. Obtained product has been studied using elementary analysis and IR spectroscopy.

  11. N-butyl-2-cyanoacrylate, iso-amyl-2-cyanoacrylate andhypertonic glucose with 72% chromated glycerin in gastricvarices

    Institute of Scientific and Technical Information of China (English)

    Reda Elwakil; Mohamed Fawzy Montasser; Sara M Abdelhakam; Wesam A Ibrahim

    2015-01-01

    cyanoacrylate and a mixture of 72% chromated glycerinwith hypertonic glucose solution in management ofgastric varices.METHODS: Ninety patients with gastric varicespresented to Endoscopy Unit of Ain Shams UniversityHospital were included. They were randomly allocatedinto three groups; each group included 30 patients treatedwith intravariceal sclerosant injections in biweeklysessions till complete obturation of gastric varices;Group I (n-butyl-2-cyanoacrylate; Histoacryl?), GroupII (iso-amyl-2-cyanoacrylate; Amcrylate?) and GroupIII (mixture of 72% chromated glycerin; Scleremo?with glucose solution 25%). All the procedures wereperformed electively without active bleeding. Recruitedpatients were followed up for 3 mo.RESULTS: 26% of Scleremo group had bleeding duringpuncture vs 3.3% in each of the other two groups withsignificant difference, (P 〈 0.05). None of Scleremogroup had needle obstruction vs 13.3% in each of theother two groups with no significant difference, (P 〉0.05). Rebleeding occurred in 13.3% of Histoacryl andAmcrylate groups vs 0% in Scleremo group with nosignificant difference. The in hospital mortality was 6.6%in both Histoacryl and Amcrylate groups, while it was0% in Scleremo group with no significant difference. Inthe first and second sessions, the amount of Scleremoneeded for obturation was significantly high, while the amount of Histoacryl was significantly low. Scleremo was the less costly of the two treatments. CONCLUSION: All used sclerosant substances showed efficacy and success in management of gastric varices with no significant differences except in total amount,cost and bleeding during puncture.

  12. TAME (tertiary-amyl-methyl ether) gasoline additive production process development; Desenvolvimento do processo de producao de TAME-aditivo para gasolina

    Energy Technology Data Exchange (ETDEWEB)

    Lovisi, Humberto [Petroflex Industria e Comercio S.A., Duqye de Caxias, RJ (Brazil); Piccoli, Ricardo [COPESUL, Companhia Petroquimica do Sul, Triunfo, RS (Brazil)

    1992-12-31

    PETROFLEX and COPESUL jointly developed a TAME production process. Tertiary-amyl-methyl ether (TAME) is obtained by the methoxylation of isoamylenes (2-methyl-1-butene and 2-methyl-2-butene) in a C{sub s} cut over a sulfonic acid resin. Process was developed on the basis of pilot plant and batch experiments. A simplified process flow-sheet and pilot plant data are presented. Isoamylenes conversions higher than 70% were achieved with low by-products formation. (author) 22 refs., 2 figs., 2 tabs.

  13. 硫酸钛催化合成丙酸异戊酯%A Study on Esterification of Propanoic Acid and iso-Amyl Alcohol Catalyzed by titanium sulphate

    Institute of Scientific and Technical Information of China (English)

    廖德仲; 何节玉

    2001-01-01

      采用Ti(SO4)2·4H2O作催化剂,探讨了丙酸和异戊醇反应的酯化条件,最佳条件下丙酸的转化率高达96%。%  Ti(SO4)2·4H2O was used as catalyst in the esterification of propanoic acid and iso-amyl alcohol. The conditions of esterification were discussed. In the optimun condition, the yield of iso-amyl propanoate was above 96%.

  14. Biodegradation of ethyl t-butyl ether (ETBE), methyl t-butyl ether (MTBE) and t-amyl methyl ether (TAME) by Gordonia terrae.

    Science.gov (United States)

    Hernandez-Perez, G; Fayolle, F; Vandecasteele, J P

    2001-01-01

    Gordonia terrae strain IFP 2001 was selected from activated sludge for its capacity to grow on ethyl t-butyl ether (ETBE) as sole carbon and energy source. ETBE was stoichiometrically degraded to t-butyl alcohol (TBA) and the activity was inducible. A constitutive strain, G. terrae IFP 2007, derived from strain IFP 2001, was also selected. Methyl t-butyl ether (MTBE) and t-amyl methyl ether (TAME) were not used as carbon and energy sources by the two strains, but cometabolic degradation of MTBE and TAME was demonstrated, to TBA and t-amyl alcohol (TAA) respectively, in the presence of a carbon source such as ethanol. No two-carbon compound was detected during growth on ETBE, but formate was produced during cometabolic degradation of MTBE or TAME. A monooxygenase was involved in the degradation of ethers, because no degradation of ETBE was observed under anaerobic conditions and the presence of a cytochrome P-450 was demonstrated in G. terrae IFP 2001 after induction by cultivation on ETBE.

  15. 水杨酸正戊酯的催化合成研究%Synthesis of n-Amyl Salicylate Catalyzed by Sodium Hydrogen Sulfate

    Institute of Scientific and Technical Information of China (English)

    杨华; 马荣萱

    2009-01-01

    n-Amyl salicylate was synthesized from salicylic acid and n-pentanol using sodium hydrogen sulfate as catalyst. Factors influencing the ether yield,such as molar ratio of alcohol to acid,catalyst dosage,reaction time,water carrier dosage were discussed. Experimental results showed that sodium hydrogen sulfate was an excellent catalyst. The optimum synthetic conditions were as follows: molar ratio of salicylic acid to n-pentanol was 1∶1.5,catalyst dosage was 4.7% of mass of the reactants,using 10 mL of cyclohexane as water carrier,reaction temperature was 120~140℃ and reaction time was 4.5 h.Under above conditions, the yield of n-amyl salicylate achieved 93.3%.%以水杨酸和正戊醇为原料,用一水合硫酸氢钠催化合成水杨酸正戊酯.研究了酸醇摩尔比、催化剂用量、反应时间及带水剂用量等因素对酯收率的影响.结果表明,一水合硫酸氢钠是合成水杨酸正戊酯的良好催化剂.最佳反应条件如下:酸醇摩尔比为1∶1.5,催化剂用量为反应物总质量的4.7%,带水剂环己烷用量为10 mL,反应时间为4.5 h,反应温度为120~140℃.在此条件下,水杨酸正戊酯的收率可达93.3%.

  16. Biodegradation of the gasoline oxygenates methyl tert-butyl ether, ethyl tert-butyl ether, and tert-amyl methyl ether by propane-oxidizing bacteria.

    Science.gov (United States)

    Steffan, R J; McClay, K; Vainberg, S; Condee, C W; Zhang, D

    1997-11-01

    Several propane-oxidizing bacteria were tested for their ability to degrade gasoline oxygenates, including methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), and tert-amyl methyl ether (TAME). Both a laboratory strain and natural isolates were able to degrade each compound after growth on propane. When propane-grown strain ENV425 was incubated with 20 mg of uniformly labeled [14C]MTBE per liter, the strain converted > 60% of the added MTBE to 14CO2 in production of nearly stoichiometric amounts of tert-butyl alcohol (TBA), while the initial oxidation of TAME resulted in the production of tert-amyl alcohol. The methoxy methyl group of MTBE was oxidized to formaldehyde and ultimately to CO2. TBA was further oxidized to 2-methyl-2-hydroxy-1-propanol and then 2-hydroxy isobutyric acid; however, neither of these degradation products was an effective growth substrate for the propane oxidizers. Analysis of cell extracts of ENV425 and experiments with enzyme inhibitors implicated a soluble P-450 enzyme in the oxidation of both MTBE and TBA. MTBE was oxidized to TBA by camphor-grown Pseudomonas putida CAM, which produces the well-characterized P-450cam, but not by Rhodococcus rhodochrous 116, which produces two P-450 enzymes. Rates of MTBE degradation by propane-oxidizing strains ranged from 3.9 to 9.2 nmol/min/mg of cell protein at 28 degrees C, whereas TBA was oxidized at a rate of only 1.8 to 2.4 nmol/min/mg of cell protein at the same temperature.

  17. Acetate Kinase Isozymes Confer Robustness in Acetate Metabolism

    DEFF Research Database (Denmark)

    Chan, Siu Hung Joshua; Nørregaard, Lasse; Solem, Christian;

    2014-01-01

    strains reveal that AckA1 has a higher capacity for acetate production which allows faster growth in an environment with high acetate concentration. Meanwhile, AckA2 is important for fast acetate-dependent growth at low concentration of acetate. The results demonstrate that the two ACKs have complementary...... physiological roles in L. lactis to maintain a robust acetate metabolism for fast growth at different extracellular acetate concentrations. The existence of ACK isozymes may reflect a common evolutionary strategy in bacteria in an environment with varying concentrations of acetate....

  18. 用于生产TAEE的反应精馏和全蒸发的混合过程%Hybrid Process of Reactive Distillation and Pervaporation for the Production of Tert-amyl Ethyl Ether

    Institute of Scientific and Technical Information of China (English)

    Amornchai Arpornwichanop; Ukrit Sahapatsombud; Yaneeporn Patcharavorachot; Suttichai Assabumrungrat

    2008-01-01

    In this study, a reactive distillation column in which chemical reaction and separation occur simultane-ously is applied for the synthesis of tert-amyl ethyl ether (TAEE) from ethanol (EtOH) and tert-amyl alcohol (TAA).Pervaporation, an efficient membrane separation technique, is integrated with the reactive distillation for enhancing the efficiency of TAEE production. A user-defined Fortran subroutine of a pervaporation unit is developed, allowing the design and simulation of the hybrid process of reactive distillation and pervaporation in Aspen Plus simulator.The performance of such a hybrid process is analyzed and the results indicate that the integration of the reactive distillation with the pervaporation increases the conversion of TAA and the purity of TAEE product, compared with the conventional reactive distiUation.

  19. Selection and identification of bacterial strains with methyl-tert-butyl ether, ethyl-tert-butyl ether, and tert-amyl methyl ether degrading capacities.

    Science.gov (United States)

    Purswani, Jessica; Pozo, Clementina; Rodríguez-Díaz, Marina; González-López, Jesús

    2008-11-01

    Nine bacterial strains isolated from two hydrocarbon-contaminated soils were selected because of their capacity for growth in culture media amended with 200 mg/L of one of the following gasoline oxygenates: Methyl-tert-butyl ether (MTBE), ethyl-tert-butyl ether (ETBE), and tert-amyl methyl ether (TAME). These strains were identified by amplification of their 16S rRNA gene, using fDl and rD1 primers, and were tested for their capacity to grow and biotransform these oxygenates in both mineral and cometabolic media. The isolates were classified as Bacillus simplex, Bacillus drentensis, Arthrobacter sp., Acinetobacter calcoaceticus, Acinetobacter sp., Gordonia amicalis (two strains), Nocardioides sp., and Rhodococcus ruber. Arthrobacter sp. (strain MG) and A. calcoaceticus (strain M10) consumed 100 (cometabolic medium) and 82 mg/L (mineral medium) of oxygenate TAME in 21 d, respectively, under aerobic conditions. Rhodococcus ruber (strain E10) was observed to use MTBE and ETBE as the sole carbon and energy source, whereas G. amicalis (strain T3) used TAME as the sole carbon and energy source for growth. All the bacterial strains transformed oxygenates better in the presence of an alternative carbon source (ethanol) with the exception of A. calcoaceticus (strain M10). The capacity of the selected strains to remove MTBE, ETBE, and TAME looks promising for application in bioremediation technologies.

  20. Preparing Process of Cerium Acetate and Rare Earth Acetate

    Institute of Scientific and Technical Information of China (English)

    Qiao Jun; Ma Ying; Xu Yanhui; Zhang Jun; Chang Shu; Hao Xianku

    2004-01-01

    Preparing process was presented and the influences of concentration of acetic acid, reaction temperature, the ratio of cerium carbonate and acetic acid, heat preservation time to the yield of cerium acetate were discussed.The crystalline cerium acetate and rare earth acetate such as ( La, Ce, Pr, Nd) (Ac) 3, ( Ce, Pr, Nd) (Ac) 3, ( Pr, Nd, Er,Y) (Ac) 3 and yttrium acetate were prepared under this condition.The shape, structure and composition of the crystals were determined by the methods of SEM, TG-DTA, X-ray diffraction and chemical analysis.The optimum prepared conditions of cerium acetate were described.This prepared process has characteristics such as simple process route, low cost, high yield, good quality, no pollution to environment, etc.

  1. 4-Carbamoylpiperidinium acetate monohydrate

    Directory of Open Access Journals (Sweden)

    Urs D. Wermuth

    2010-12-01

    Full Text Available In the structure of the title compound, C6H13N2O+·C2H3O2−·H2O, the amide H atoms of the cations form centrosymmetric cyclic hydrogen-bonding associations incorporating two water molecules [graph set R42(8], which are conjoint with cyclic water-bridged amide–amide associations [R44(12] and larger R44(20 associations involving the water molecule and the acetate anions, which bridge through the piperidinium H-bond donors, giving an overall three-dimensional framework structure.

  2. Threshold Acetate Concentrations for Acetate Catabolism by Aceticlastic Methanogenic Bacteria

    OpenAIRE

    Westermann, Peter; Ahring, Birgitte K.; Mah, Robert A.

    1989-01-01

    Marked differences were found for minimum threshold concentrations of acetate catabolism by Methanosarcina barkeri 227 (1.180 mM), Methanosarcina mazei S-6 (0.396 mM), and a Methanothrix sp. (0.069 mM). This indicates that the aceticlastic methanogens responsible for the conversion of acetate to methane in various ecosystems might be different, depending on the prevailing in situ acetate concentrations.

  3. Kallolide A acetate pyrazoline.

    Science.gov (United States)

    Rodríguez-Escudero, Idaliz; Marrero, Jeffrey; Rodríguez, Abimael D

    2012-01-01

    IN THE CRYSTAL STRUCTURE OF KALLOLIDE A ACETATE PYRAZOLINE [SYSTEMATIC NAME: 7-methyl-16-oxo-4,10-bis-(prop-1-en-2-yl)-17,18-dioxa-14,15-diaza-tetra-cyclo-[9.4.2.1(6,9).0(1,12)]octa-deca-6,8,14-trien-5-yl acetate], C(23)H(28)N(2)O(5), there is a 12-member-ed carbon macrocyclic structure. In addition, there is a tris-ubstituted furan ring, an approximately planar γ-lactone ring [maximum deviation of 0.057 (3) Å] and a pyraz-oline ring, the latter in an envelope conformation. The pyrazoline and the γ-lactone rings are fused in a cis configuration. In the crystal, mol-ecules are linked by weak C-H⋯O inter-actions, forming a two-dimensional network parallel to (001). An intra-molecular C-H⋯O hydrogen bond is also present.

  4. Liquid/air partition coefficients of methyl and ethyl T-butyl ethers, T-amyl methyl ether, and T-butyl alcohol.

    Science.gov (United States)

    Nihlen, A; Lof, A; Johanson, G

    1995-01-01

    Partition coefficients are essential to a description of the uptake and distribution of volatile substances in humans and in the development of physiologically based pharmacokinetic models. Liquid/air partition coefficients (lambda) of three ethers, methyl t-butyl ether (MTBE), ethyl t-butyl ether (ETBE), and t-amyl methyl ether (TAME) were determined in vitro by head space-gas chromatography. These ethers, and especially MTBE, are used in unleaded gasoline to enhance the oxygen and octane content, and to reduce the output of carbon monoxide during combustion. Partition coefficients of t-butyl alcohol (TBA), a metabolite of MTBE, were determined also. The liquids tested were fresh human blood, water (physiological saline), and olive oil. The (lambda)blood/air values were: 17.7 (95% confidence interval 17.0-18.4) for MTBE; 11.7 (11.3-12.1) for ETBE; and 17.9 (17.3-18.5) for TAME. Corresponding (lambda)water/air values were 15.2 (14.9-15.5), 8.39 (8.19-8.59), and 11.9 (11.7-12.1). The ethers have a higher affinity for oil, the values for (lambda)oil/air being 120 (114-125), 190 (183-197), and 337 (320-354), respectively. As expected, the (lambda)blood/air and (lambda)water/air for TBA were much higher than for the ethers, 462 (440-484) and 603 (590-617), respectively. The (lambda)oil/air was 168 (161-174) for TBA. The interindividual variability of the (lambda)blood/air (10 subjects) was calculated as the coefficient of variation, and estimated as: 14% for MTBE, 20% for ETBE, 20% for TAME, and 30% for TBA. No significant difference was seen in the (lambda)blood/air between the sexes.

  5. Antibiofilm Properties of Acetic Acid

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Alhede, Morten; Jensen, Peter Østrup;

    2014-01-01

    of the infected implant, tissue, or organ and thereby the biofilm. Acetic acid is known for its antimicrobial effect on bacteria in general, but has never been thoroughly tested for its efficacy against bacterial biofilms. In this article, we describe complete eradication of both Gram-positive and Gram......-negative biofilms using acetic acid both as a liquid and as a dry salt. In addition, we present our clinical experience of acetic acid treatment of chronic wounds. In conclusion, we here present the first comprehensive in vitro and in vivo testing of acetic acid against bacterial biofilms....

  6. ACETIC ACID AND A BUFFER

    DEFF Research Database (Denmark)

    2009-01-01

    The present invention relates to a composition comprising : a) 0.01-20% wt/wt acetic acid and b) a physiologically tolerable buffer capable of maintaining acetic acid at a pH in the range of 2-7; and use of such a composition as an antimicrobial agent.......The present invention relates to a composition comprising : a) 0.01-20% wt/wt acetic acid and b) a physiologically tolerable buffer capable of maintaining acetic acid at a pH in the range of 2-7; and use of such a composition as an antimicrobial agent....

  7. Acetate metabolism in Methanothrix soehngenii.

    NARCIS (Netherlands)

    Jetten, M.S.M.

    1991-01-01

    Acetate is quantitatively the most important intermediate in the anaerobic degradation of soluble organic matter. The conversion rate of acetate by methanogenic bacteria is proposed to be the rate limiting step in this degradation The study of acetoclastic methanogens, therefore is of relevance to o

  8. 过氧化叔戊醇对苯并噻吩类衍生物的氧化%Oxidation of benzothiophenes using tert-amyl hydroperoxide

    Institute of Scientific and Technical Information of China (English)

    周新锐; 盖洪涛; 王静; 张珊珊; 杨锦宗; 张淑芬

    2009-01-01

    Homogeneous oxidation using an oil-soluble oxidant,tert-amyl hydroperoxide(TAHP).for ultra-deep desulfurizmion was performed under mild conditions in the presence of molybdenum oxide catalysts.Dibenzothio phene(DBT),benzothiophcne(BT)and 4,6-dimethyl-dibenzothiophene(DMDBT),which are the refractory sulfur compounds for hydrodesulfurization(HDS),were employed as model substrates for a simulated diesel fuel.Activ ity of molybdenum oxide supported on a macroporous weak acidic resin was investigated.The mass conversion of DBT reached near 100%at 90°C and a TAHP,DBT molar ratio of 3 with 1% of molybdenum oxide supported on Amberlite IRC-748 resin for l h.It was further found that the activities of the model Substrates decreasca rin the order of DMDBT>DBT>B T.In the flow oxidation using TAHP as the oxidant,mass conversion of DBT increased remarkably from 61.3%to 98.5%when dropping the weight hourly space velocity(WHSV)from 40 h1 to 10 h-1.A series of experiments dealt with selectivity of this oxidation using TAHP revealed that the model unsaturated compounds,i.e.4,6,8-trimethyl-2-nonylene,and 2-methylnaphthaIene did not affect the oxidation of DBT.Carbazole had nearly no effect on the conversion of DBT using TAHP.but had some influence on the one using tert-butyl hydroperoxide(TBHP).The mass conversion of DBT decreased remarkably from 75.2%to 3.6%when the content of carbazole increased from 0 to 500 ug.g-1.In the flow oxidation using TAHP as the oxidant.the concentration of.DBT in model fuels was reduced from 500 ug.g-1 to 7.2 ug.g-1 at WHSV of 10 h-1,and then reduced to 3.8 ug.g-1 by adsorption of Al2O3.

  9. Zinc Acetate Immobilized on Mesoporous Materials by Acetate Ionic Liquids as Catalysts for Vinyl Acetate Synthesis

    Directory of Open Access Journals (Sweden)

    Hang Xu

    2015-01-01

    Full Text Available Ionic liquid containing active ingredient Zn(CH3COO2 was loaded in mesoporous silica gel to form supported ionic liquids catalyst (SILC which was used to synthesize vinyl acetate monomer (VAM. SILC was characterized by 1HNMR, FT-IR, TGA, BET, and N2 adsorption/desorption and the acetylene method was used to evaluate SILC catalytic activity and stability in fixed reactor. The result shows that 1-allyl-3-acetic ether imidazole acetate ionic liquid is successfully fixed within mesoporous channel of silica gel. The average thickness of ionic liquid catalyst layer is about 1.05 nm. When the catalytic temperature is 195°C, the acetic acid (HAc conversion is 10.9% with 1.1 g vinyl acetate yield and 98% vinyl acetate (VAc selectivity. The HAc conversion is increased by rise of catalytic temperature and molar ratio of C2H2 : HAc and decreased by mass space velocity (WHSV. The catalyst activity is not significantly reduced within 7 days and VAc selectivity has a slight decrease.

  10. Analysis of proteins responsive to acetic acid in Acetobacter: molecular mechanisms conferring acetic acid resistance in acetic acid bacteria.

    Science.gov (United States)

    Nakano, Shigeru; Fukaya, Masahiro

    2008-06-30

    Acetic acid bacteria are used for industrial vinegar production because of their remarkable ability to oxidize ethanol and high resistance to acetic acid. Although several molecular machineries responsible for acetic acid resistance in acetic acid bacteria have been reported, the entire mechanism that confers acetic acid resistance has not been completely understood. One of the promising methods to elucidate the entire mechanism is global analysis of proteins responsive to acetic acid by two-dimensional gel electrophoresis. Recently, two proteins whose production was greatly enhanced by acetic acid in Acetobacter aceti were identified to be aconitase and a putative ABC-transporter, respectively; furthermore, overexpression or disruption of the genes encoding these proteins affected acetic acid resistance in A. aceti, indicating that these proteins are involved in acetic acid resistance. Overexpression of each gene increased acetic acid resistance in Acetobacter, which resulted in an improvement in the productivity of acetic acid fermentation. Taken together, the results of the proteomic analysis and those of previous studies indicate that acetic acid resistance in acetic acid bacteria is conferred by several mechanisms. These findings also provide a clue to breed a strain having high resistance to acetic acid for vinegar fermentation.

  11. 5-(Chloromethylquinolin-8-yl acetate

    Directory of Open Access Journals (Sweden)

    Ling-Qian Kong

    2008-08-01

    Full Text Available The title compound, C12H10ClNO2, crystallizes with two independent molecules in the asymmetric unit; these are approximate mirror images of each other. In each molecule, the chloromethyl and acetate groups lie on the same side of the quinoline ring system, with dihedral angles between the ring plane and the plane of the acetate group of 82.0 (1 and −79.2 (1°. The C—C—C—Cl torsion angles for the chloromethyl groups of the two molecules are 80.9 (2 and −83.1 (2°.

  12. Desmopressin Acetate in Intracranial Haemorrhage

    Directory of Open Access Journals (Sweden)

    Thomas Kapapa

    2014-01-01

    Full Text Available Introduction. The secondary increase in the size of intracranial haematomas as a result of spontaneous haemorrhage or trauma is of particular relevance in the event of prior intake of platelet aggregation inhibitors. We describe the effect of desmopressin acetate as a means of temporarily stabilising the platelet function. Patients and Methods. The platelet function was analysed in 10 patients who had received single (N=4 or multiple (N=6 doses of acetylsalicylic acid and 3 patients (control group who had not taken acetylsalicylic acid. All subjects had suffered intracranial haemorrhage. Analysis was performed before, half an hour and three hours after administration of desmopressin acetate. Statistical analysis was performed by applying a level of significance of P≤0.05. Results. (1 Platelet function returned to normal 30 minutes after administration of desmopressin acetate. (2 The platelet function worsened again after three hours. (3 There were no complications related to electrolytes or fluid balance. Conclusion. Desmopressin acetate can stabilise the platelet function in neurosurgical patients who have received acetylsalicylic acid prior to surgery without causing transfusion-related side effects or a loss of time. The effect is, however, limited and influenced by the frequency of drug intake. Further controls are needed in neurosurgical patients.

  13. Carbon-isotopic analysis of dissolved acetate.

    Science.gov (United States)

    Gelwicks, J T; Hayes, J M

    1990-01-01

    Heating of dried, acetate-containing solids together with oxalic acid dihydrate conveniently releases acetic acid for purification by gas chromatography. For determination of the carbon-isotopic composition of total acetate, the acetate-containing zone of the chromatographic effluent can be routed directly to a combustion furnace coupled to a vacuum system allowing recovery, purification, and packaging of CO2 for mass-spectrometric analysis. For analysis of methyl carbon, acetic acid can be cryogenically trapped from the chromatographic effluent, then transferred to a tube containing excess NaOH. The tube is evacuated, sealed, and heated to 500 degrees C to produce methane by pyrolysis of sodium acetate. Subsequent combustion of the methane allows determination of the 13C content at the methyl position in the parent acetate. With typical blanks, the standard deviation of single analyses is less than 0.4% for acetate samples larger than 5 micromoles. A full treatment of uncertainties is outlined.

  14. Pallidol hexaacetate ethyl acetate monosolvate

    Directory of Open Access Journals (Sweden)

    Qinyong Mao

    2013-07-01

    Full Text Available The entire molecule of pallidol hexaacetate {systematic name: (±-(4bR,5R,9bR,10R-5,10-bis[4-(acetyloxyphenyl]-4b,5,9b,10-tetrahydroindeno[2,1-a]indene-1,3,6,8-tetrayl tetraacetate} is completed by the application of twofold rotational symmetry in the title ethyl acetate solvate, C40H34O12·C4H8O2. The ethyl acetate molecule was highly disordered and was treated with the SQUEEZE routine [Spek (2009. Acta Cryst. D65, 148–155]; the crystallographic data take into account the presence of the solvent. In pallidol hexaacetate, the dihedral angle between the fused five-membered rings (r.m.s. deviation = 0.100 Å is 54.73 (6°, indicating a significant fold in the molecule. Significant twists between residues are also evident as seen in the dihedral angle of 80.70 (5° between the five-membered ring and the pendent benzene ring to which it is attached. Similarly, the acetate residues are twisted with respect to the benzene ring to which they are attached [C—O(carboxy—C—C torsion angles = −70.24 (14, −114.43 (10 and −72.54 (13°]. In the crystal, a three-dimensional architecture is sustained by C—H...O interactions which encompass channels in which the disordered ethyl acetate molecules reside.

  15. 21 CFR 582.1005 - Acetic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acetic acid. 582.1005 Section 582.1005 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1005 Acetic acid. (a) Product. Acetic acid. (b) Conditions of use. This substance is...

  16. 21 CFR 522.2476 - Trenbolone acetate.

    Science.gov (United States)

    2010-04-01

    ... days. (A) 140 milligrams (mg) trenbolone acetate (one implant consisting of 7 pellets, each pellet containing 20 mg trenbolone acetate) per implant dose. (B) 140 mg trenbolone acetate (one implant consisting... 29 mg tylosin tartrate) per implant dose. (ii) Indications for use. For improved feed...

  17. Disruption of the acetate kinase (ack) gene of Clostridium acetobutylicum results in delayed acetate production

    NARCIS (Netherlands)

    Kuit, W.; Minton, N.P.; Lopez Contreras, A.M.; Eggink, G.

    2012-01-01

    In microorganisms, the enzyme acetate kinase (AK) catalyses the formation of ATP from ADP by de-phosphorylation of acetyl phosphate into acetic acid. A mutant strain of Clostridium acetobutylicum lacking acetate kinase activity is expected to have reduced acetate and acetone production compared to t

  18. Chemical and biologic characteristics of roxatidine acetate.

    Science.gov (United States)

    Bickel, M; Herling, A W; Schoelkens, B; Scholtholt, J

    1988-01-01

    Roxatidine acetate is a specific and competitive H2-receptor antagonist, as shown in isolated rabbit gastric glands or guinea pig atria preparations. The antisecretory effect of roxatidine acetate is mediated by its main metabolite, roxatidine. In the rat, roxatidine acetate was equipotent after intraduodenal and intraperitoneal administration, indicating excellent bioavailability. Roxatidine acetate and roxatidine were equipotent in the rat after intravenous administration. In the Heidenhain-pouch dog stimulated by food ingestion or maximal histamine dosing, roxatidine acetate and roxatidine proved to be 3-6 times more potent than cimetidine in inhibiting gastric acid secretion. From in vitro experiments it can be concluded that roxatidine acetate and ranitidine are equipotent. Roxatidine acetate has no antiandrogenic effects and does not influence drug-metabolizing enzymes in the liver.

  19. Crystal structure of the catalytic domain of PigE: a transaminase involved in the biosynthesis of 2-methyl-3-n-amyl-pyrrole (MAP) from Serratia sp. FS14.

    Science.gov (United States)

    Lou, Xiangdi; Ran, Tingting; Han, Ning; Gao, Yanyan; He, Jianhua; Tang, Lin; Xu, Dongqing; Wang, Weiwu

    2014-04-25

    Prodigiosin, a tripyrrole red pigment synthesized by Serratia and some other microbes through a bifurcated biosynthesis pathway, MBC (4-methoxy-2,2'-bipyrrole-5-carbaldehyde) and MAP (2-methyl-3-n-amyl-pyrrole) are synthesized separately and then condensed by PigC to form prodigiosin. MAP is synthesized sequentially by PigD, PigE and PigB. PigE catalyzes the transamination of an amino group to the aldehyde group of 3-acetyloctanal, resulting in an aminoketone, which spontaneously cyclizes to form H2MAP. Here we report the crystal structure of the catalytic domain of PigE which involved in the biosynthesis of prodigiosin precursor MAP for the first time to a resolution of 2.3Å with a homodimer in the asymmetric unit. The monomer of PigE catalytic domain is composed of three domains with PLP as cofactor: a small N-terminal domain connecting the catalytic domain with the front part of PigE, a large PLP-binding domain and a C-terminal domain. The residues from both monomers build the PLP binding site at the interface of the dimer which resembles the other PLP-dependent enzymes. Structural comparison of PigE with Thermus thermophilus AcOAT showed a higher hydrophobic and smaller active site of PigE, these differences may be the reason for substrate specificity.

  20. Co-extraction and co-stripping of U(VI) and Pu(IV) using tri-iso-amyl phosphate and tri-n-butyl phosphate in n-dodecane from nitric acid media under high loading conditions

    Energy Technology Data Exchange (ETDEWEB)

    Sreenivasulu, Balija; Suresh, Ammath; Sivaraman, Nagarajan; Rao, P.R. Vasudeva [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Chemistry Group

    2016-08-01

    The extraction of Pu(IV) using 1.1 M solution of tri-iso-amyl phosphate (TiAP)/n-dodecane (DD) from plutonium nitrate solutions in nitric acid media was examined as a function of equilibrium aqueous phase metal ion concentration and equilibrium aqueous phase acidity at 303 K. The nitric acid concentration in the organic phase was measured as a function of equilibrium organic phase plutonium concentration. The co-extraction of U(VI) and Pu(IV) was studied using 1.1 M TiAP/DD system as a function of their equilibrium aqueous phase metal ion concentration and compared with 1.1 M tri-n-butyl phosphate (TBP)/n-DD system under identical conditions. Co-extraction and co-stripping of U(VI) and Pu(IV) were studied using 1.1 M TiAP/DD and 1.1 M TBP/DD systems in cross current mode to evaluate the number of stages required for the extraction and stripping of heavy metal ions (uranium and plutonium). The extraction and stripping efficiencies were calculated for both the systems. The saturation limit of the organic phase was also established in these studies.

  1. Vapor intrusion risk of fuel ether oxygenates methyl tert-butyl ether (MTBE), tert-amyl methyl ether (TAME) and ethyl tert-butyl ether (ETBE): A modeling study.

    Science.gov (United States)

    Ma, Jie; Xiong, Desen; Li, Haiyan; Ding, Yi; Xia, Xiangcheng; Yang, Yongqi

    2017-06-15

    Vapor intrusion of synthetic fuel additives represents a critical yet still neglected problem at sites contaminated by petroleum fuel releases. This study used an advanced numerical model to investigate the vapor intrusion potential of fuel ether oxygenates methyl tert-butyl ether (MTBE), tert-amyl methyl ether (TAME), and ethyl tert-butyl ether (ETBE). Simulated indoor air concentration of these compounds can exceed USEPA indoor air screening level for MTBE (110μg/m(3)). Our results also reveal that MTBE has much higher chance to cause vapor intrusion problems than TAME and ETBE. This study supports the statements made by USEPA in the Petroleum Vapor Intrusion (PVI) Guidance that the vertical screening criteria for petroleum hydrocarbons may not provide sufficient protectiveness for fuel additives, and ether oxygenates in particular. In addition to adverse impacts on human health, ether oxygenate vapor intrusion may also cause aesthetic problems (i.e., odour and flavour). Overall, this study points out that ether oxygenates can cause vapor intrusion problems. We recommend that USEPA consider including the field measurement data of synthetic fuel additives in the existing PVI database and possibly revising the PVI Guidance as necessary.

  2. Determination of low level methyl tert-butyl ether, ethyl tert-butyl ether and methyl tert-amyl ether in human urine by HS-SPME gas chromatography/mass spectrometry.

    Science.gov (United States)

    Scibetta, Licia; Campo, Laura; Mercadante, Rosa; Foà, Vito; Fustinoni, Silvia

    2007-01-02

    Methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE) and tert-amyl methyl ether (TAME) are oxygenated compounds added to gasoline to enhance octane rating and to improve combustion. They may be found as pollutants of living and working environments. In this work a robotized method for the quantification of low level MTBE, ETBE and TAME in human urine was developed and validated. The analytes were sampled in the headspace of urine by SPME in the presence of MTBE-d12 as internal standard. Different fibers were compared for their linearity and extraction efficiency: carboxen/polydimethylsiloxane, polydimethylsiloxane/divinylbenzene, and polydimethylsiloxane. The first, although highly efficient, was discarded due to deviation of linearity for competitive displacement, and the polydimethylsiloxane/divinylbenzene fiber was chosen instead. The analysis was performed by GC/MS operating in the electron impact mode. The method is very specific, with range of linearity 30-4600 ng L(-1), within- and between-run precision, as coefficient of variation, ethers was evaluated analysing the specimens of seven traffic policemen exposed to autovehicular emissions: using the calibration curve and the method of standard additions comparable levels of MTBE (68-528 ng L(-1)), ETBE (<6 ng L(-1)), and TAME (<6 ng L(-1)) were obtained.

  3. Single-walled carbon nanotubes as an effective adsorbent in solid-phase microextraction of low level methyl tert-butyl ether, ethyl tert-butyl ether and methyl tert-amyl ether from human urine.

    Science.gov (United States)

    Rastkari, Noushin; Ahmadkhaniha, Reza; Yunesian, Masud

    2009-05-15

    Carbon nanotubes (CNTs) are a kind of new carbon-based nano-materials which have drawn great attention in many application fields. The potential single-walled carbon nanotubes (SWCNTs) as solid-phase microextraction (SPME) adsorbents for the preconcentration of environmental pollutants have been investigated in recent years. The goal of this work was to investigate the feasibility of SWCNTs used as adsorbents for solid-phase microextraction of methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE) and tert-amyl methyl ether (TAME) in human urine. SWCNTs were attached onto a stainless steel wire through organic binder. Potential factors affecting the extraction efficiency were optimized, including extraction time, extraction temperature, desorption time, desorption temperature, and salinity. The developed method showed good performance according to the ICH performance criteria for bioanalytical methods. The calibration curves of the ethers were linear (r(2)>or=0.992) in the range from 10 to 5000 ng L(-1). The limits of detection at a signal-to-noise (S/N) ratio of 3 were 10 ng L(-1) for all the analytes. In addition, compared with the commercial carboxen/polydimethylsiloxane (CAR/PDMS) fiber, the SWCNT fiber showed better thermal stability (over 350 degrees C) and longer life span (over 150 times). The developed method was applied successfully to determine trace level of the ethers in urine of 10 healthy male volunteers.

  4. Isobaric Vapor-Liquid Equilibrium of Binary Systems: p-Xylene + (Acetic Acid, Methyl Acetate and n-Propyl Acetate)and Methyl Acetate + n-Propyl Acetate in an Acetic Acid Dehydration Process

    Institute of Scientific and Technical Information of China (English)

    HUANG Xiuhui; ZHONG Weimin; PENG Changjun; QIAN Feng

    2013-01-01

    The vapor-liquid equilibrium data of four binary systems(acetic acid + p-xylene,methyl acetate + n-propyl acetate,n-propyl acetate + p-xylene and methyl acetate + p-xylene)are measured at 101.33 kPa with Ellis equilibrium still,and then both the NRTL and UNIQUAC models are used in combination with the HOC model for correlating and estimating the vapor-liquid equilibrium of these four binary systems.The estimated binary VLE results using correlated parameters agree well with the measured data except the methyl acetate + p-xylene system which easily causes bumping and liquid rushing out of the sampling tap due to their dramatically different boiling points.The correlation results by NRTL and UNIQUAC models have little difference on the average absolute deviations of temperature and composition of vapor phase,and the results by NRTL model are slightly better than those by UNIQUAC model except for the methyl acetate + n-propyl acetate system,for which the latter gives more accurate correlations.

  5. 21 CFR 184.1005 - Acetic acid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acetic acid. 184.1005 Section 184.1005 Food and... Substances Affirmed as GRAS § 184.1005 Acetic acid. (a) Acetic acid (C2H4O2, CAS Reg. No. 64-19-7) is known as ethanoic acid. It occurs naturally in plant and animal tissues. It is produced by fermentation...

  6. Extractive fermentation of acetic acid

    Energy Technology Data Exchange (ETDEWEB)

    Busche, R.M. [Bio En-Gene-Er Associates, Inc., Wilmington, DE (United States)

    1991-12-31

    In this technoeconomic evaluation of the manufacture of acetic acid by fermentation, the use of the bacterium: Acetobacter suboxydans from the old vinegar process was compared with expected performance of the newer Clostridium thermoaceticum bacterium. Both systems were projected to operate as immobilized cells in a continuous, fluidized bed bioreactor, using solvent extraction to recover the product. Acetobacter metabolizes ethanol aerobically to produce acid at 100 g/L in a low pH medium. This ensures that the product is in the form of a concentrated extractable free acid, rather than as an unextractable salt. Unfortunately, yields from glucose by way of the ethanol fermentation are poor, but near the biological limits of the organisms involved. Conversely, C. thermoaceticum is a thermophilic anaerobe that operates at high fermentation rates on glucose at neutral pH to produce acetate salts directly in substantially quantitative yields. However, it is severely inhibited by product, which restricts concentration to a dilute 20 g/L. An improved Acetobacter system operating with recycled cells at 50 g/L appears capable of producing acid at $0.38/lb, as compared with a $0.29/lb price for synthetic acid. However, this system has only a limited margin for process improvement. The present Clostridium system cannot compete, since the required selling price would be $0.42/lb. However, if the organism could be adapted to tolerate higher product concentrations at acid pH, selling price could be reduced to $0.22/lb, or about 80% of the price of synthetic acid.

  7. Optimization of coproduction of ethyl acetate and n-butyl acetate by reactive distillation☆

    Institute of Scientific and Technical Information of China (English)

    Hui Tian; Suying Zhao; Huidong Zheng; Zhixian Huang

    2015-01-01

    Based on a previous investigation, a simulation model was used for optimization of coproduction of ethyl acetate and n-butyl acetate by reactive distil ation. An experimental setup was established to verify the simulated results. The effects of various operating variables, such as ethanol feed location, acetic acid feed location, feed stage of reaction mixture of acetic acid and n-butanol, reflux ratio of ethyl acetate reactive distillation column, and distil-late to feed ratio of n-butyl acetate column, on the ethanol/n-butanol conversions, ethyl acetate/n-butyl acetate purity, and energy consumption were investigated. The optimal results in the simulation study are as follows:ethanol feed location, 15th stage;acetic acid feed location, eighth stage;feed location of reaction mixture of acetic acid and n-butanol, eighth stage;reflux ratio of ethyl acetate reactive distillation column, 2.0;and distillate to feed ratio of n-butyl acetate, 0.6.

  8. Manufacturing Ethyl Acetate From Fermentation Ethanol

    Science.gov (United States)

    Rohatgi, Naresh K.; Ingham, John D.

    1991-01-01

    Conceptual process uses dilute product of fermentation instead of concentrated ethanol. Low-concentration ethanol, extracted by vacuum from fermentation tank, and acetic acid constitutes feedstock for catalytic reaction. Product of reaction goes through steps that increases ethyl acetate content to 93 percent by weight. To conserve energy, heat exchangers recycle waste heat to preheat process streams at various points.

  9. Direct Oxidation of Ethene to Acetic Acid

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Direct oxidation of ethene to acetic acid over Pd-SiW12/SiO2 catalysts prepared by several methods was studied. A better method for reducing palladium composition of the catalysts was found. Acetic acid was obtained with selectivity of 82.7% and once-through space time yield (STY) of 257.4 g/h×L.

  10. Desvenlafaxinium chloranilate ethyl acetate solvate

    Directory of Open Access Journals (Sweden)

    Manpreet Kaur

    2013-10-01

    Full Text Available In the cation of the title compound, C16H26NO2+·C6HCl2O4−·C4H8O2, the 1-hydroxy-cyclohexyl ring adopts a slightly distorted chair conformation. The dihedral angle between the mean planes of the 1-hydroxycyclohexyl and 4-hydroxyphenyl rings is 84.0 (8°. In the anion, the hydroxyl H atom is twisted slightly out of the ring plane with a C—C—O—H torsion angle of −171.9°. Disorder was modeled for the methyl group of the acetate group in the solvate with an occupancy ratio of 0.583 (15: 0.417 (15. In the crystal, O—H...O hydrogen bonds are observed between cations and between cations and anions, while bifuricated N—H...(O,O cation–anion hydrogen bonds are also present, forming chains along [010] and [100]. In addition weak cation–anion and cation–solvate C—H...O interactions occur.

  11. Predominant contribution of syntrophic acetate oxidation to thermophilic methane formation at high acetate concentrations.

    Science.gov (United States)

    Hao, Li-Ping; Lü, Fan; He, Pin-Jing; Li, Lei; Shao, Li-Ming

    2011-01-15

    To quantify the contribution of syntrophic acetate oxidation to thermophilic anaerobic methanogenesis under the stressed condition induced by acidification, the methanogenic conversion process of 100 mmol/L acetate was monitored simultaneously by using isotopic tracing and selective inhibition techniques, supplemented with the analysis of unculturable microorganisms. Both quantitative methods demonstrated that, in the presence of aceticlastic and hydrogenotrophic methanogens, a large percentage of methane (up to 89%) was initially derived from CO(2) reduction, indicating the predominant contribution of the syntrophic acetate oxidation pathway to acetate degradation at high acid concentrations. A temporal decrease of the fraction of hydrogenotrophic methanogenesis from more than 60% to less than 40% reflected the gradual prevalence of the aceticlastic methanogenesis pathway along with the reduction of acetate. This apparent discrimination of acetate methanization pathways highlighted the importance of the syntrophic acetate-oxidizing bacteria to initialize methanogenesis from high organic loadings.

  12. Determination of low level methyl tert-butyl ether, ethyl tert-butyl ether and methyl tert-amyl ether in human urine by HS-SPME gas chromatography/mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Scibetta, Licia [Department of Occupational and Environmental Medicine, University of Milano and Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Via S. Barnaba, 8-20122 Milan (Italy); Campo, Laura [Department of Occupational and Environmental Medicine, University of Milano and Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Via S. Barnaba, 8-20122 Milan (Italy); Mercadante, Rosa [Department of Occupational and Environmental Medicine, University of Milano and Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Via S. Barnaba, 8-20122 Milan (Italy); Foa, Vito [Department of Occupational and Environmental Medicine, University of Milano and Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Via S. Barnaba, 8-20122 Milan (Italy); Fustinoni, Silvia [Department of Occupational and Environmental Medicine, University of Milano and Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Via S. Barnaba, 8-20122 Milan (Italy)]. E-mail: silvia.fustinoni@unimi.it

    2007-01-02

    Methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE) and tert-amyl methyl ether (TAME) are oxygenated compounds added to gasoline to enhance octane rating and to improve combustion. They may be found as pollutants of living and working environments. In this work a robotized method for the quantification of low level MTBE, ETBE and TAME in human urine was developed and validated. The analytes were sampled in the headspace of urine by SPME in the presence of MTBE-d12 as internal standard. Different fibers were compared for their linearity and extraction efficiency: carboxen/polydimethylsiloxane, polydimethylsiloxane/divinylbenzene, and polydimethylsiloxane. The first, although highly efficient, was discarded due to deviation of linearity for competitive displacement, and the polydimethylsiloxane/divinylbenzene fiber was chosen instead. The analysis was performed by GC/MS operating in the electron impact mode. The method is very specific, with range of linearity 30-4600 ng L{sup -1}, within- and between-run precision, as coefficient of variation, <22 and <16%, accuracy within 20% the theoretical level, and limit of detection of 6 ng L{sup -1} for all the analytes. The influence of the matrix on the quantification of these ethers was evaluated analysing the specimens of seven traffic policemen exposed to autovehicular emissions: using the calibration curve and the method of standard additions comparable levels of MTBE (68-528 ng L{sup -1}), ETBE (<6 ng L{sup -1}), and TAME (<6 ng L{sup -1}) were obtained.

  13. Bacterial degradation of tert-amyl alcohol proceeds via hemiterpene 2-methyl-3-buten-2-ol by employing the tertiary alcohol desaturase function of the Rieske nonheme mononuclear iron oxygenase MdpJ.

    Science.gov (United States)

    Schuster, Judith; Schäfer, Franziska; Hübler, Nora; Brandt, Anne; Rosell, Mònica; Härtig, Claus; Harms, Hauke; Müller, Roland H; Rohwerder, Thore

    2012-03-01

    Tertiary alcohols, such as tert-butyl alcohol (TBA) and tert-amyl alcohol (TAA) and higher homologues, are only slowly degraded microbially. The conversion of TBA seems to proceed via hydroxylation to 2-methylpropan-1,2-diol, which is further oxidized to 2-hydroxyisobutyric acid. By analogy, a branched pathway is expected for the degradation of TAA, as this molecule possesses several potential hydroxylation sites. In Aquincola tertiaricarbonis L108 and Methylibium petroleiphilum PM1, a likely candidate catalyst for hydroxylations is the putative tertiary alcohol monooxygenase MdpJ. However, by comparing metabolite accumulations in wild-type strains of L108 and PM1 and in two mdpJ knockout mutants of strain L108, we could clearly show that MdpJ is not hydroxylating TAA to diols but functions as a desaturase, resulting in the formation of the hemiterpene 2-methyl-3-buten-2-ol. The latter is further processed via the hemiterpenes prenol, prenal, and 3-methylcrotonic acid. Likewise, 3-methyl-3-pentanol is degraded via 3-methyl-1-penten-3-ol. Wild-type strain L108 and mdpJ knockout mutants formed isoamylene and isoprene from TAA and 2-methyl-3-buten-2-ol, respectively. It is likely that this dehydratase activity is catalyzed by a not-yet-characterized enzyme postulated for the isomerization of 2-methyl-3-buten-2-ol and prenol. The vitamin requirements of strain L108 growing on TAA and the occurrence of 3-methylcrotonic acid as a metabolite indicate that TAA and hemiterpene degradation are linked with the catabolic route of the amino acid leucine, including an involvement of the biotin-dependent 3-methylcrotonyl coenzyme A (3-methylcrotonyl-CoA) carboxylase LiuBD. Evolutionary aspects of favored desaturase versus hydroxylation pathways for TAA conversion and the possible role of MdpJ in the degradation of higher tertiary alcohols are discussed.

  14. Acetic acid fermentation of acetobacter pasteurianus: relationship between acetic acid resistance and pellicle polysaccharide formation.

    Science.gov (United States)

    Kanchanarach, Watchara; Theeragool, Gunjana; Inoue, Taketo; Yakushi, Toshiharu; Adachi, Osao; Matsushita, Kazunobu

    2010-01-01

    Acetobacter pasteurianus strains IFO3283, SKU1108, and MSU10 were grown under acetic acid fermentation conditions, and their growth behavior was examined together with their capacity for acetic acid resistance and pellicle formation. In the fermentation process, the cells became aggregated and covered by amorphous materials in the late-log and stationary phases, but dispersed again in the second growth phase (due to overoxidation). The morphological change in the cells was accompanied by changes in sugar contents, which might be related to pellicle polysaccharide formation. To determine the relationship between pellicle formation and acetic acid resistance, a pellicle-forming R strain and a non-forming S strain were isolated, and their fermentation ability and acetic acid diffusion activity were compared. The results suggest that pellicle formation is directly related to acetic acid resistance ability, and thus is important to acetic acid fermentation in these A. pasteurianus strains.

  15. Acetate intolerance and an inhibitor of acetate utilization in hemodialysis patients

    Energy Technology Data Exchange (ETDEWEB)

    Egan, J.D.; Wells, I.C.

    1979-03-01

    Diminished ability to utilize acetate (acetate intolerance) developed in a male patient on chronic hemodialysis after five years of maintenance dialysis. His ability to utilize lactate was also subnormal. We studied acetate metabolism in vitro by isolating lymphocytes from the patient's blood before dialysis and measuring their ability to convert (1-/sub 14/C)acetate to /sub 14/CO2. His cells metabolized acetate only 35% as well as did lymphocytes from normal adults. The inhibition appeared when the patient's lymphocytes were cultured, and the ability of normal lymphocytes to oxidize acetate decreased after they had been incubated in the patient's plasma. We conclude that an inhibitor of acetate utilization is present in the plasma and in (or on) the cells of this acetate-intolerant patient. The diminished ability of the patient to utilize lactate and the presence of normal concentrations of pyruvate, citrate, and ketone bodies in his blood suggest that the inhibitor functions at the cell surface to impede the entrance of acetate into the cells. The inhibitor appears to be dialyzable; its nature is unknown. Its accumulation in the plasma of chronic hemodialysis patients has not been thus far associated with any deleterious effects other than prolonging the metabolic acidosis of such patients.

  16. Clinical characteristics of roxatidine acetate: a review.

    Science.gov (United States)

    Dammann, H G; de Looze, S M; Bender, W; Labs, R

    1988-01-01

    Pharmacodynamic studies revealed that 150 mg of roxatidine acetate were optimal in suppressing gastric acid secretion, and that a single bedtime dose of 150 mg was more effective than a dose of 75 mg twice daily in terms of inhibiting nocturnal acid secretion. When administered orally as a capsule containing a granule formulation, the drug displayed modified-release properties, which led to a sustained suppression of gastric acid secretion. Clinical trials revealed that roxatidine acetate, 75 mg twice daily and 150 mg at night, was highly effective in healing duodenal and gastric ulcers and in reducing ulcer pain, over 4, 6, and 8 weeks of therapy. A steady reduction in diameter was observed in those ulcers not completely healed during therapy. The single bedtime dose regimen, while producing the same degree of healing as the divided daily dose during controlled clinical trials, may be of greater value in therapeutic use owing to improved patient compliance. In all efficacy criteria (cure, reduction in ulcer size, and pain relief) there was no significant difference between roxatidine acetate in a total daily dose of 150 mg, ranitidine in a total daily dose of 300 mg, and cimetidine in a total daily dose of 800 mg. Prevention of gastric and duodenal ulcer relapse was achieved by roxatidine acetate, 75 mg at night for 6 months, in about 70% of patients, as determined in open, pilot studies--a rate comparable to those reported for cimetidine and ranitidine. Roxatidine acetate shares with ranitidine an improved safety profile when compared with cimetidine. Human pharmacology studies and short-term and long-term clinical trials have all shown that roxatidine acetate is an exceptionally well tolerated compound, without the antiandrogenic activity and interference with hepatic drug metabolism which have characterized cimetidine treatment. A reason for the improved safety profile of roxatidine acetate may be its greater potency than cimetidine (six times less potent) and

  17. Acetic acid production from food wastes using yeast and acetic acid bacteria micro-aerobic fermentation.

    Science.gov (United States)

    Li, Yang; He, Dongwei; Niu, Dongjie; Zhao, Youcai

    2015-05-01

    In this study, yeast and acetic acid bacteria strains were adopted to enhance the ethanol-type fermentation resulting to a volatile fatty acids yield of 30.22 g/L, and improve acetic acid production to 25.88 g/L, with food wastes as substrate. In contrast, only 12.81 g/L acetic acid can be obtained in the absence of strains. The parameters such as pH, oxidation reduction potential and volatile fatty acids were tested and the microbial diversity of different strains and activity of hydrolytic ferment were investigated to reveal the mechanism. The optimum pH and oxidation reduction potential for the acetic acid production were determined to be at 3.0-3.5 and -500 mV, respectively. Yeast can convert organic matters into ethanol, which is used by acetic acid bacteria to convert the organic wastes into acetic acid. The acetic acid thus obtained from food wastes micro-aerobic fermentation liquid could be extracted by distillation to get high-pure acetic acid.

  18. Tested Demonstrations: Buffer Capacity of Various Acetic Acid-Sodium Acetate Systems: A Lecture Experiment.

    Science.gov (United States)

    Donahue, Craig J.; Panek, Mary G.

    1985-01-01

    Background information and procedures are provided for a lecture experiment which uses indicators to illustrate the concept of differing buffer capacities by titrating acetic acid/sodium acetate buffers with 1.0 molar hydrochloric acid and 1.0 molar sodium hydroxide. A table with data used to plot the titration curve is included. (JN)

  19. Acetylation of Starch with Vinyl Acetate in Imidazolium Ionic Liquids and Characterization of Acetate Distribution

    Science.gov (United States)

    Starch was acetylated with vinyl acetate in different 1-butyl-3-methylimidazolium (BMIM) salts as solvent in effort to produce starches with different acetylation patterns. Overall degree of substitution was much higher for basic anions such as acetate and dicyanimide (dca) than for neutral anions ...

  20. [Roxatidine acetate in therapy of reflux esophagitis].

    Science.gov (United States)

    Friedrich, P; Botzler, R; Mayershofer, R; Kriech, W

    1996-06-10

    A total of 3409 patients with gastro-oesophageal reflux disease were treated with roxatidine acetate. 60.7% of the patients received a daily dose of 2 x 75 mg roxatidine acetate, and the median duration of treatment was 5 weeks. Symptoms improved in about 90% of patients. For 1687 patients, endoscopic findings were available at the beginning and end of the treatment period. The overall endoscopic healing rate was 65.3%, and, depending on the initial finding (if), decreased from 92.9% (if: Savary-Miller stage I) to 67.5% (if: stage II), 40.7% (if: stage III), and to 22.5% (if: stage IV). Twenty-one patients experienced adverse events during the course of treatment, which, however, were either only minor or not related to the use of roxatidine acetate.

  1. Hydrolysis of Acetic Anhydride in a CSTR

    Directory of Open Access Journals (Sweden)

    Veronica N. Coraci

    2016-05-01

    Full Text Available To find the optimal reactor volume and temperature for the hydrolysis of acetic anhydride at the lowest possible cost with a 90% conversion of acetic anhydride, a formula for the total cost of the reaction was created. Then, the first derivative was taken to find a value for the temperature. This value was then inputted into the second derivative of the equation to find the sign of the value which would indicate whether that point was a minima or maxima value. The minima value would then be the lowest total cost for the optimum reaction to take place.

  2. Fierce Competition in China's Ethyl Acetate Market

    Institute of Scientific and Technical Information of China (English)

    Wang Zichang

    2007-01-01

    @@ Ethyl acetate is used extensively in the coatings, inks, pharmaceuticals,adhesives, cosmetics and organic synthesis sectors. With the sustained stable growth of China's national economy, the construction and automobile sectors are developing rapidly and environmental protection laws and regulations are becoming stricter.

  3. Megestrol acetate in cachexia and anorexia

    Science.gov (United States)

    Yeh, Shing-shing; Schuster, Michael W

    2006-01-01

    The aim is to review major clinical trials that have used megestrol acetate (MA) in the treatment of cachexia across several disease states. A review of general usage and potential side-effects are discussed. A theory that the newly approved nanocrystal formation of MA can better deliver this potent medication for treatment will also be reviewed. PMID:17722275

  4. Heat Bonding of Irradiated Ethylene Vinyl Acetate

    Science.gov (United States)

    Slack, D. H.

    1986-01-01

    Reliable method now available for joining parts of this difficult-tobond material. Heating fixture encircles ethylene vinyl acetate multiplesocket part, providing heat to it and to tubes inserted in it. Fixtures specially designed to match parts to be bonded. Tube-and-socket bonds made with this technique subjected to tensile tests. Bond strengths of 50 percent that of base material obtained consistently.

  5. Advanced Colloids Experiment (ACE-T1)

    Science.gov (United States)

    Meyer, William V.; Sicker, Ron; Brown, Dan; Eustace, John

    2015-01-01

    Increment 45 - 46 Science Symposium presentation of Advanced Colloids Experiment (ACE-T1) to RPO. The purpose of this event is for Principal Investigators to present their science objectives, testing approach, and measurement methods to agency scientists, managers, and other investigators.

  6. Phenyl Acetate Preparation from Phenol and Acetic Acid: Reassessment of a Common Textbook Misconception.

    Science.gov (United States)

    Hocking, M. B.

    1980-01-01

    Reassesses a common textbook misconception that "...phenols cannot be esterified directly." Results of experiments are discussed and data tables provided of an effective method for the direct preparation of phenyl acetate. (CS)

  7. Correlation of vapor - liquid equilibrium data for acetic acid - isopropanol - water - isopropyl acetate mixtures

    Directory of Open Access Journals (Sweden)

    B. A. Mandagarán

    2006-03-01

    Full Text Available A correlation procedure for the prediction of vapor - liquid equilibrium of acetic acid - isopropanol - water - isopropyl acetate mixtures has been developed. It is based on the NRTL model for predicting liquid activity coefficients, and on the Hayden-O'Connell second virial coefficients for predicting the vapor phase of systems containing association components. When compared with experimental data the correlation shows a good agreement for binary and ternary data. The correlation also shows good prediction for reactive quaternary data.

  8. Nasal pungency, odor, and eye irritation thresholds for homologous acetates.

    Science.gov (United States)

    Cometto-Muñiz, J E; Cain, W S

    1991-08-01

    We measured detection thresholds for nasal pungency (in anosmics), odor (in normosmics) and eye irritation employing a homologous series of acetates: methyl through octyl acetate, decyl and dodecyl acetate. All anosmics reliably detected the series up to heptyl acetate. Only the anosmics without smell since birth (congenital) reliably detected octyl acetate, and only one congenital anosmic detected decyl and dodecyl acetate. Anosmics who lost smell from head trauma proved to be selectively less sensitive. As expected, odor thresholds lay well below pungency thresholds. Eye irritation thresholds for selected acetates came close to nasal pungency thresholds. All three types of thresholds decreased logarithmically with carbon chain length, as previously seen with homologous alcohols and as seen in narcotic and toxic phenomena. Results imply that nasal pungency for these stimuli rests upon a physical, rather than chemical, interaction with susceptible mucosal structures. When expressed as thermodynamic activity, nasal pungency thresholds remain remarkably constant within and across the homologous series of acetates and alcohols.

  9. Expression of acetate permease-like (apl) genes in subsurface communities of Geobacter species under fluctuating acetate concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Elifantz, H.; N' Guessan, L.A.; Mouser, P.J.; Williams, K H.; Wilkins, M J.; Risso, C.; Holmes, D.E.; Long, P.E.; Lovley, D.R.

    2010-03-01

    The addition of acetate to uranium-contaminated aquifers in order to stimulate the growth and activity of Geobacter species that reduce uranium is a promising in situ bioremediation option. Optimizing this bioremediation strategy requires that sufficient acetate be added to promote Geobacter species growth. We hypothesized that under acetate-limiting conditions, subsurface Geobacter species would increase the expression of either putative acetate symporters genes (aplI and aplII). Acetate was added to a uranium-contaminated aquifer (Rifle, CO) in two continuous amendments separated by 5 days of groundwater flush to create changing acetate concentrations. While the expression of aplI in monitoring well D04 (high acetate) weakly correlated with the acetate concentration over time, the transcript levels for this gene were relatively constant in well D08 (low acetate). At the lowest acetate concentrations during the groundwater flush, the transcript levels of aplII were the highest. The expression of aplII decreased 2-10-fold upon acetate reintroduction. However, the overall instability of acetate concentrations throughout the experiment could not support a robust conclusion regarding the role of apl genes in response to acetate limitation under field conditions, in contrast to previous chemostat studies, suggesting that the function of a microbial community cannot be inferred based on lab experiments alone.

  10. PHOTOCOPOLYMERIZATION OF MALEIC ANHYDRIDE AND VINYL ACETATE

    Institute of Scientific and Technical Information of China (English)

    LI Xiaofang; LI Shanjun; QIN Anwei; YU Tongyin

    1990-01-01

    The charge-transfer complex of maleic anhydride and vinyl acetate was copolymerized under UV light. The chain composition and structure of the copolymer were analyzed with conductometry and NMR, and the chain sequence was determined as alternating. The copolymerization rates at different feed ratios, temperatures and in different solvents were investigated, giving evidence to the very active involvement of the CT complexes in the copolymerization. Terpolymerization with acrylonitrile also showed that the complex mechanism was a proper one for this system.

  11. Acetate in Oz: Some Strategic Moves

    Directory of Open Access Journals (Sweden)

    Colin Webb

    2005-08-01

    Full Text Available I would like to add my voice to the words of congratulations and thanks to the British Library for organising this forum, and for their generosity in making it possible for me to come across the world to be part of it. The issues we are discussing today have an importance extending beyond cellulose acetate, as they reflect our ability as custodians to deal with common threats to the documentary heritage we are charged with preserving. As I will argue later, we need to see this situation in the context of the full range of preservation management issues that face our institutions. While it imposes a burden and a challenge on us as preservation managers, it also presents opportunities to sort out some things that have needed attention for some time. I have been asked to talk about problems with cellulose acetate microfilm collections in Australia, and specifically the strategies – both national and local – that have been adopted or at least explored in response to those problems. In the time I have I will not be going into any of these in great detail, but I hope I can give you some sense of the situation down under, and perhaps draw out a few issues that might make this more than just an ‘us too’ session! One thing to emphasise from the start is that we have had a number of goes at dealing with acetate microfilm collections: it is not a newly discovered problem in Australia. One significant context in which we have been working is that of a national strategy for all kinds of cellulose acetate collection materials. Explaining this national strategy will form a major part of my presentation, with issues and approaches specific to microfilm discussed towards the end.

  12. Microbial acetate oxidation in horizontal rotating tubular bioreactor

    Indian Academy of Sciences (India)

    A Slavica; B Šantek; S Novak; V Marić

    2004-06-01

    The aim of this work was to investigate the possibility of conducting a continuous aerobic bioprocess in a horizontal rotating tubular bioreactor (HRTB). Aerobic oxidation of acetate by the action of a mixed microbial culture was chosen as a model process. The microbial culture was not only grown in a suspension but also in the form of a biofilm on the interior surface of HRTB. Efficiency of the bioprocess was monitored by determination of the acetate concentration and chemical oxygen demand (COD). While acetate inlet concentration and feeding rate influenced efficiency of acetate oxidation, the bioreactor rotation speed did not influence the bioprocess dynamics significantly. Gradients of acetate concentration and pH along HRTB were more pronounced at lower feeding rates. Volumetric load of acetate was proved to be the most significant parameter. High volumetric loads (above 2 g acetate l–1 h–1) gave poor acetate oxidation efficiency (only 17 to 50%). When the volumetric load was in the range of 0.60–1.75 g acetate l–1 h–1, acetate oxidation efficiency was 50–75%. At lower volumetric loads (0.14–0.58 g acetate l–1 h–1), complete acetate consumption was achieved. On the basis of the obtained results, it can be concluded that HRTB is suitable for conducting aerobic continuous bioprocesses.

  13. Kinetics of Ethyl Acetate Synthesis Catalyzed by Acidic Resins

    Science.gov (United States)

    Antunes, Bruno M.; Cardoso, Simao P.; Silva, Carlos M.; Portugal, Ines

    2011-01-01

    A low-cost experiment to carry out the second-order reversible reaction of acetic acid esterification with ethanol to produce ethyl acetate is presented to illustrate concepts of kinetics and reactor modeling. The reaction is performed in a batch reactor, and the acetic acid concentration is measured by acid-base titration versus time. The…

  14. 21 CFR 582.5933 - Vitamin A acetate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Vitamin A acetate. 582.5933 Section 582.5933 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5933 Vitamin A acetate. (a) Product. Vitamin A acetate. (b) Conditions of use....

  15. 21 CFR 177.1350 - Ethylene-vinyl acetate copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-vinyl acetate copolymers. 177.1350 Section... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1350 Ethylene-vinyl acetate copolymers. Ethylene-vinyl acetate copolymers may be safely used as articles or components of...

  16. Acetic acid extraction from aqueous solutions using fatty acids

    NARCIS (Netherlands)

    IJmker, H.M.; Gramblicka, M.; Kersten, S.R.A.; Ham, van der A.G.J.; Schuur, B.

    2014-01-01

    A major challenge for production of acetic acid via bio-based routes is cost-effective concentration and purification of the acetic acid from the aqueous solutions, for which liquid–liquid extraction is a possible method. A main challenge in extraction of acetic acid from dilute aqueous solutions is

  17. Co-fermentation of acetate and sugars facilitating microbial lipid production on acetate-rich biomass hydrolysates.

    Science.gov (United States)

    Gong, Zhiwei; Zhou, Wenting; Shen, Hongwei; Yang, Zhonghua; Wang, Guanghui; Zuo, Zhenyu; Hou, Yali; Zhao, Zongbao K

    2016-05-01

    The process of lignocellulosic biomass routinely produces a stream that contains sugars plus various amounts of acetic acid. As acetate is known to inhibit the culture of microorganisms including oleaginous yeasts, little attention has been paid to explore lipid production on mixtures of acetate and sugars. Here we demonstrated that the yeast Cryptococcus curvatus can effectively co-ferment acetate and sugars for lipid production. When mixtures of acetate and glucose were applied, C. curvatus consumed both substrates simultaneously. Similar phenomena were also observed for acetate and xylose mixtures, as well as acetate-rich corn stover hydrolysates. More interestingly, the replacement of sugar with equal amount of acetate as carbon source afforded higher lipid titre and lipid content. The lipid products had fatty acid compositional profiles similar to those of cocoa butter, suggesting their potential for high value-added fats and biodiesel production. This co-fermentation strategy should facilitate lipid production technology from lignocelluloses.

  18. Simultaneous production of acetic and gluconic acids by a thermotolerant Acetobacter strain during acetous fermentation in a bioreactor

    OpenAIRE

    Majid MOUNIR; Shafiei, Rasoul; Zarmehrkhorshid, Raziyeh; Hamouda, Allal; Ismaili Alaoui, Mustapha; Thonart, Philippe

    2016-01-01

    The activity of bacterial strains significantly influences the quality and the taste of vinegar. Previous studies of acetic acid bacteria have primarily focused on the ability of bacterial strains to produce high amounts of acetic acid. However, few studies have examined the production of gluconic acid during acetous fermentation at high temperatures. The production of vinegar at high temperatures by two strains of acetic acid bacteria isolated from apple and cactus fruits, namely AF01 and CV...

  19. A NOVEL COPOLYMER-BOUND CIS- DICARBONYLRHODIUM COMPLEX FOR THE CARBONYLATION OF METHANOL TO ACETIC ACID AND ACETIC ANHYDRIDE

    Institute of Scientific and Technical Information of China (English)

    YUAN Guoqing; CHEN Yuying; CHEN Rongyao

    1989-01-01

    A series of porous microspheres of linear and ethylene diacrylate (M ') cross-linked copolymers of 2 - vinylpyridine (V) and methyl acrylate (M) reacted with tetracarbonyldichlorodirhodium to form a series of cis-dicarbonylrhodium chelate complex (MVRh and MVM 'Rh). They are thermally stable yet very reactive in the carbonylation of methanol to acetic acid, and of methanol - acetic acid mixture to acetic acid and acetic anhydride with a selectivity of 100% under relatively mild and anhydrous conditions.

  20. Overview on mechanisms of acetic acid resistance in acetic acid bacteria.

    Science.gov (United States)

    Wang, Bin; Shao, Yanchun; Chen, Fusheng

    2015-02-01

    Acetic acid bacteria (AAB) are a group of gram-negative or gram-variable bacteria which possess an obligate aerobic property with oxygen as the terminal electron acceptor, meanwhile transform ethanol and sugar to corresponding aldehydes, ketones and organic acids. Since the first genus Acetobacter of AAB was established in 1898, 16 AAB genera have been recorded so far. As the main producer of a world-wide condiment, vinegar, AAB have evolved an elegant adaptive system that enables them to survive and produce a high concentration of acetic acid. Some researches and reviews focused on mechanisms of acid resistance in enteric bacteria and made the mechanisms thoroughly understood, while a few investigations did in AAB. As the related technologies with proteome, transcriptome and genome were rapidly developed and applied to AAB research, some plausible mechanisms conferring acetic acid resistance in some AAB strains have been published. In this review, the related mechanisms of AAB against acetic acid with acetic acid assimilation, transportation systems, cell morphology and membrane compositions, adaptation response, and fermentation conditions will be described. Finally, a framework for future research for anti-acid AAB will be provided.

  1. Compound list: desmopressin acetate [Open TG-GATEs

    Lifescience Database Archive (English)

    Full Text Available desmopressin acetate DDAVP 00159 ftp://ftp.biosciencedbc.jp/archive/open-tggates/LA...TEST/Rat/in_vivo/Liver/Single/desmopressin_acetate.Rat.in_vivo.Liver.Single.zip ftp://ftp.biosciencedbc.jp/a...rchive/open-tggates/LATEST/Rat/in_vivo/Liver/Repeat/desmopressin_acetate.Rat.in_vivo.Liver.Repeat.zip ftp://...ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Kidney/Single/desmopre...ssin_acetate.Rat.in_vivo.Kidney.Single.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Kidney/Repeat/desmopressin_acetate.Rat.in_vivo.Kidney.Repeat.zip ...

  2. Acetic acid removal from corn stover hydrolysate using ethyl acetate and the impact on Saccharomyces cerevisiae bioethanol fermentation.

    Science.gov (United States)

    Aghazadeh, Mahdieh; Ladisch, Michael R; Engelberth, Abigail S

    2016-07-08

    Acetic acid is introduced into cellulose conversion processes as a consequence of composition of lignocellulose feedstocks, causing significant inhibition of adapted, genetically modified and wild-type S. cerevisiae in bioethanol fermentation. While adaptation or modification of yeast may reduce inhibition, the most effective approach is to remove the acetic acid prior to fermentation. This work addresses liquid-liquid extraction of acetic acid from biomass hydrolysate through a pathway that mitigates acetic acid inhibition while avoiding the negative effects of the extractant, which itself may exhibit inhibition. Candidate solvents were selected using simulation results from Aspen Plus™, based on their ability to extract acetic acid which was confirmed by experimentation. All solvents showed varying degrees of toxicity toward yeast, but the relative volatility of ethyl acetate enabled its use as simple vacuum evaporation could reduce small concentrations of aqueous ethyl acetate to minimally inhibitory levels. The toxicity threshold of ethyl acetate, in the presence of acetic acid, was found to be 10 g L(-1) . The fermentation was enhanced by extracting 90% of the acetic acid using ethyl acetate, followed by vacuum evaporation to remove 88% removal of residual ethyl acetate along with 10% of the broth. NRRL Y-1546 yeast was used to demonstrate a 13% increase in concentration, 14% in ethanol specific production rate, and 11% ethanol yield. This study demonstrated that extraction of acetic acid with ethyl acetate followed by evaporative removal of ethyl acetate from the raffinate phase has potential to significantly enhance ethanol fermentation in a corn stover bioethanol facility. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:929-937, 2016.

  3. Detoxification of biomass derived acetate via metabolic conversion to ethanol, acetone, isopropanol, or ethyl acetate

    Energy Technology Data Exchange (ETDEWEB)

    Sillers, William Ryan; Van Dijken, Hans; Licht, Steve; Shaw, IV, Arthur J.; Gilbert, Alan Benjamin; Argyros, Aaron; Froehlich, Allan C.; McBride, John E.; Xu, Haowen; Hogsett, David A.; Rajgarhia, Vineet B.

    2017-03-28

    One aspect of the invention relates to a genetically modified thermophilic or mesophilic microorganism, wherein a first native gene is partially, substantially, or completely deleted, silenced, inactivated, or down-regulated, which first native gene encodes a first native enzyme involved in the metabolic production of an organic acid or a salt thereof, thereby increasing the native ability of said thermophilic or mesophilic microorganism to produce lactate or acetate as a fermentation product. In certain embodiments, the aforementioned microorganism further comprises a first non-native gene, which first non-native gene encodes a first non-native enzyme involved in the metabolic production of lactate or acetate. Another aspect of the invention relates to a process for converting lignocellulosic biomass to lactate or acetate, comprising contacting lignocellulosic biomass with a genetically modified thermophilic or mesophilic microorganism.

  4. Adaptation and tolerance of bacteria against acetic acid.

    Science.gov (United States)

    Trček, Janja; Mira, Nuno Pereira; Jarboe, Laura R

    2015-08-01

    Acetic acid is a weak organic acid exerting a toxic effect to most microorganisms at concentrations as low as 0.5 wt%. This toxic effect results mostly from acetic acid dissociation inside microbial cells, causing a decrease of intracellular pH and metabolic disturbance by the anion, among other deleterious effects. These microbial inhibition mechanisms enable acetic acid to be used as a preservative, although its usefulness is limited by the emergence of highly tolerant spoilage strains. Several biotechnological processes are also inhibited by the accumulation of acetic acid in the growth medium including production of bioethanol from lignocellulosics, wine making, and microbe-based production of acetic acid itself. To design better preservation strategies based on acetic acid and to improve the robustness of industrial biotechnological processes limited by this acid's toxicity, it is essential to deepen the understanding of the underlying toxicity mechanisms. In this sense, adaptive responses that improve tolerance to acetic acid have been well studied in Escherichia coli and Saccharomyces cerevisiae. Strains highly tolerant to acetic acid, either isolated from natural environments or specifically engineered for this effect, represent a unique reservoir of information that could increase our understanding of acetic acid tolerance and contribute to the design of additional tolerance mechanisms. In this article, the mechanisms underlying the acetic acid tolerance exhibited by several bacterial strains are reviewed, with emphasis on the knowledge gathered in acetic acid bacteria and E. coli. A comparison of how these bacterial adaptive responses to acetic acid stress fit to those described in the yeast Saccharomyces cerevisiae is also performed. A systematic comparison of the similarities and dissimilarities of the ways by which different microbial systems surpass the deleterious effects of acetic acid toxicity has not been performed so far, although such exchange

  5. Different cerebrovascular effects of medroxyprogesterone acetate and norethisterone acetate in the New Zealand White rabbit

    DEFF Research Database (Denmark)

    Pedersen, S H; Pedersen, N G; Dalsgaard, T;

    2004-01-01

    of different progestins on cerebrovascular reactivity in an animal model. METHODS: Fifty-six ovariectomized New Zealand White rabbits were randomized into seven groups receiving hormone treatment for 4 weeks: medroxyprogesterone acetate (MPA) (10 mg/day); norethisterone acetate (NETA) (3 mg/day); conjugated....... No overall differences were seen between CEE and E2. CONCLUSIONS: In rabbit cerebral arteries, MPA treatment causes a higher development in arterial tension compared with NETA, indicating that different progestins may display different cerebrovascular effects. However, when accompanied by estrogens...

  6. POLYMER—SUPPORTED RHODIUM CATALYSTS FOR CARBONYLATION OF METHYL ACETATE TO ACETIC ANHYDRIDE

    Institute of Scientific and Technical Information of China (English)

    CHENDean; HUANGShizhuan; 等

    1993-01-01

    Two kinds of rhodium catalysts supported on cross-linked styrene-divinylbenzene copolymers containing bipyridine or o-phenylene diamine have been prepared and found to display high activity for methyl acetate carbonylation to form acetic anhydride,the activities are even higher than their homogeneous counterparts. XPS analysis was used to characterize the synthetic catalysts.The apparent activation parameters were determined to be Eα=73.3KJ/mol,ΔH≠=66.3KJ/mol,ΔS≠=-28.6eu.These parameters are very close to those in methanol carbonylation and imply to have analogous mechanism in both cases.

  7. Sphingolipids contribute to acetic acid resistance in Zygosaccharomyces bailii.

    Science.gov (United States)

    Lindahl, Lina; Genheden, Samuel; Eriksson, Leif A; Olsson, Lisbeth; Bettiga, Maurizio

    2016-04-01

    Lignocellulosic raw material plays a crucial role in the development of sustainable processes for the production of fuels and chemicals. Weak acids such as acetic acid and formic acid are troublesome inhibitors restricting efficient microbial conversion of the biomass to desired products. To improve our understanding of weak acid inhibition and to identify engineering strategies to reduce acetic acid toxicity, the highly acetic-acid-tolerant yeast Zygosaccharomyces bailii was studied. The impact of acetic acid membrane permeability on acetic acid tolerance in Z. bailii was investigated with particular focus on how the previously demonstrated high sphingolipid content in the plasma membrane influences acetic acid tolerance and membrane permeability. Through molecular dynamics simulations, we concluded that membranes with a high content of sphingolipids are thicker and more dense, increasing the free energy barrier for the permeation of acetic acid through the membrane. Z. bailii cultured with the drug myriocin, known to decrease cellular sphingo-lipid levels, exhibited significant growth inhibition in the presence of acetic acid, while growth in medium without acetic acid was unaffected by the myriocin addition. Furthermore, following an acetic acid pulse, the intracellular pH decreased more in myriocin-treated cells than in control cells. This indicates a higher inflow rate of acetic acid and confirms that the reduction in growth of cells cultured with myriocin in the medium with acetic acid was due to an increase in membrane permeability, thereby demonstrating the importance of a high fraction of sphingolipids in the membrane of Z. bailii to facilitate acetic acid resistance; a property potentially transferable to desired production organisms suffering from weak acid stress.

  8. Methylprednisolon acetate in the management of

    Directory of Open Access Journals (Sweden)

    N. Khaci, M.D.

    2008-01-01

    Full Text Available AbstractBackground and Purpose: Acute renal colic is a common complaint from patients entering the emergency departments. Although, urethral lithotripsy and extracorporeal shock wave lithotripsy are known to be effective, the role of medical-expulsive therapy for the treatment of this disease has not yet been established. This study assessed the clinical efficacy of addition methylprednisolon acetate in the medical-expulsive therapy of distal ureterolithiasis.Materials and Methods: Eighty five (85 consecutive patients with a symptomatic distal urethral stone were included in our study and randomized to one of two home treatment groups. Group A patients (n = 45 received tramadol (50mg bid and hydrochlorothiazide (50 mg daily for 21 days, and group B patients (n = 40 were treated with a corticosteroid drug (methylprednisolon acetate 40mg intra-muscular on 0, 7 and 14 days after treatment, in addition to tramadol and hydrochlorothiazide. The treatment duration was 21 days. All patients were re-evaluated after 21days with a clinical examination and KUB.Results: The mean stone size was 5.2mm and 5.8mm in groups A and B respectively (P value>0.05. Both groups had a significant difference in expulsion rate (20(44.4% for group A and 32 (88% for group B; (P value<0.001.Conclusion: Our results suggest that the use of a corticosteroid drug in association with tramadol and hydro-cholorothiazid appeared to induce an increase in the expulsion ra

  9. Immunotoxicity of trenbolone acetate in Japanese quail

    Science.gov (United States)

    Quinn, M.J.; McKernan, M.; Lavoie, E.T.; Ottinger, M.A.

    2007-01-01

    Trenbolone acetate is a synthetic androgen that is currently used as a growth promoter in many meat-exporting countries. Despite industry laboratories classifying trenbolone as nonteratogenic, data showed that embryonic exposure to this androgenic chemical altered development of the immune system in Japanese quail. Trenbolone is lipophilic, persistent, and released into the environment in manure used as soil fertilizer. This is the first study to date to assess this chemical's immunotoxic effects in an avian species. A one-time injection of trenbolone into yolks was administered to mimic maternal deposition, and subsequent effects on the development and function of the immune system were determined in chicks and adults. Development of the bursa of Fabricius, an organ responsible for development of the humoral arm of the immune system, was disrupted, as indicated by lower masse, and smaller and fewer follicles at day 1 of hatch. Morphological differences in the bursas persisted in adults, although no differences in either two measures of immune function were observed. Total numbers of circulating leukocytes were reduced and heterophil-lymphocyte ratios were elevated in chicks but not adults. This study shows that trenbolone acetate is teratogenic and immunotoxic in Japanese quail, and provides evidence that the quail immune system may be fairly resilient to embryonic endocrine-disrupting chemical-induced alterations following no further exposure posthatch.

  10. Genetic dissection of acetic acid tolerance in Saccharomyces cerevisiae.

    Science.gov (United States)

    Geng, Peng; Xiao, Yin; Hu, Yun; Sun, Haiye; Xue, Wei; Zhang, Liang; Shi, Gui-Yang

    2016-09-01

    Dissection of the hereditary architecture underlying Saccharomyces cerevisiae tolerance to acetic acid is essential for ethanol fermentation. In this work, a genomics approach was used to dissect hereditary variations in acetic acid tolerance between two phenotypically different strains. A total of 160 segregants derived from these two strains were obtained. Phenotypic analysis indicated that the acetic acid tolerance displayed a normal distribution in these segregants, and suggested that the acetic acid tolerant traits were controlled by multiple quantitative trait loci (QTLs). Thus, 220 SSR markers covering the whole genome were used to detect QTLs of acetic acid tolerant traits. As a result, three QTLs were located on chromosomes 9, 12, and 16, respectively, which explained 38.8-65.9 % of the range of phenotypic variation. Furthermore, twelve genes of the candidates fell into the three QTL regions by integrating the QTL analysis with candidates of acetic acid tolerant genes. These results provided a novel avenue to obtain more robust strains.

  11. Methane-to-acetic acid synthesis matriculates at Penn State

    Energy Technology Data Exchange (ETDEWEB)

    Rotman, D.

    1994-04-20

    Direct conversion of methane to commercially valuable chemicals remains one of the grails of industrial chemistry. But scientists at Pennsylvania State University (University Park) appear to have made a significant step forward, reporting the direct catalytic conversion of methane into acetic acid under relatively mild conditions. Commercial acetic production involves a three-step process, including steam reforming of methane to synthesis gas (syngas) and the carbonylation of methanol of acetic acid.

  12. Leuprorelin Acetate in Prostate Cancer: a European Update

    OpenAIRE

    Persad R

    2002-01-01

    This review provides an update on leuprorelin acetate, the world's most widely prescribed depot luteinising hormone-releasing hormone analogue. Leuprorelin acetate has been in clinical use in the palliative treatment of prostate cancer for more than 20 years, but advances continue to be made in terms of convenience and flexibility of administration, and in the incorporation of leuprorelin acetate into novel treatment regimens. The drug is administered in the form of a depot injection containi...

  13. Fermentation characteristics of Fusarium oxysporum grown on acetate

    DEFF Research Database (Denmark)

    Panagiotou, Gianni; Pachidou, Fotini; Petroutsos, Dimitris

    2008-01-01

    In this study, the growth characteristics of Fusarium oxysporum were evaluated in minimal medium using acetate or different mixtures of acetate and glucose as carbon source. The minimum inhibitory concentration (MIC) of acetic acid that F oxysporum cells could tolerate was 0.8% w/v while glucose...... of succinate-propionate pathway which consumes reducing power (NADH) via conversion of succinate to propionyl-CoA and produce propionate. (C) 2008 Elsevier Ltd. All rights reserved....

  14. The acetate kinase of Clostridum acetobutylicum strain P262.

    Science.gov (United States)

    Diez-Gonzalez, F; Russell, J B; Hunter, J B

    1996-12-01

    Clostridum acetobutylicum strain P262 fermented glucose, pyruvate, or lactate, and the butyrate production was substrate-dependent. Differences in butyrate yield could not be explained by changes in butyrate kinase activities, but the butyrate production was inversely related to acetate kinase activity. The acetate kinase had a pH optimum of 8.0, a Km for acetate of 160 mM, and a kcat of 16, 800 min-1. The enyzme had a native molecular mass of 78 kDa; the size of 42 kDa on SDS-PAGE indicated that the acetate kinase of strain P262 was a homodimer.

  15. Cytoprotective action of roxatidine acetate HCl.

    Science.gov (United States)

    Shiratsuchi, K; Fuse, H; Hagiwara, M; Mikami, T; Miyasaka, K; Sakuma, H

    1988-01-01

    The cytoprotective action of roxatidine acetate HCl (roxatidine) was investigated. We also studied the involvement of endogenous prostaglandins (PGs) in the cytoprotective action of roxatidine and the effect of roxatidine on SRS content in pleurisy induced by A23187. Simultaneously, these effects of roxatidine were compared with those of other histamine H2-receptor antagonists at the same anti-secretory activity level. Roxatidine prevented formation of the gastric mucosal lesions induced by abs. ethanol, 0.6 N HCl and 0.2 N NaOH, but it failed to prevent 30% NaCl-induced gastric mucosal lesions. Cimetidine, ranitidine and famotidine failed to prevent formation of the gastric mucosal lesions induced by necrotizing agents. The cytoprotective action of roxatidine was not abolished by pretreatment with indomethacin. Roxatidine did not greatly influence SRS production. Consequently, it appears that roxatidine has a cytoprotective action and that this action is not associated with endogenous PGs and SRS.

  16. Unsuccessful treatment of acromegaly with medroxyprogesterone acetate.

    Science.gov (United States)

    Atkinson, R L; Dimond, R C; Howard, W J; Earll, J M

    1974-09-01

    6 patients with active acromegaly were treated with 10 mg of medroxyprogesterone acetate (MPA) every 6 hours daily for 2 weeks to 6 months. Oral glucose tolerance tests, growth hormone (GH) levels, and insulin tolerance tests (ITT) were done before and during MPA treatment. Basal GH levels varied widely during control and therapy periods; no significant lowering of GH levels occurred during treatment. Carbohydrate tolerance was not significantly affected by MPA therapy, although 5 out of 6 patients had deterioration at least once during treatment. Blood glucose response to ITT was unchanged by MPA. MPA did not affect the clinical features of acromegaly. There was no consistent effect of MPA on insulin-induced or arginine-induced GH secretion. It is concluded that MPA is not an effective agent for treating acromegaly.

  17. Acetic orcein staining of prefixed tissue sections.

    Science.gov (United States)

    Reynolds, C; Lillie, R D

    1978-05-01

    Acetic orcein stains formol- and Carnoy-fixed tissues, coloring mast cells, nuclei, basophilic cytoplasm, cerebral corpora amylacea, and cartilage strongly; keratin and erythrocytes moderately; muscle and collagen weakly. Guinea pig Brunner gland and rat colonic goblet cell mucins did not stain. The red nuclear stain contrasts well with the Prussian blue reaction of hemosiderin and the ferric ferricyanide (Turnbull's blue) reaction of enterochromaffin. A weak (0.01%) fast-green FCF stain changes collagen and sometimes smooth muscle to green, without impairing nucleic acid or mast cell staining. Picroindigocarmine gives blue collagen, yellow muscle, and red elastin, nucleic acids and mast cells. Picro-methyl blue tends to override the red nuclear stain. Carnoy fixation is somewhat better for nuclei, formol for basophil cytoplasms.

  18. Emergency contraception: potential role of ulipristal acetate

    Directory of Open Access Journals (Sweden)

    Kristina Gemzell-Danielsson

    2010-04-01

    Full Text Available Kristina Gemzell-Danielsson, Chun-Xia MengDepartment of Women’s and Children’s Health, Division of Obstetrics and Gynecology, Karolinska Institutet, Stockholm, SwedenAbstract: Unintended pregnancy is a global reproductive health problem. Emergency contraception (EC provides women with a safe means of preventing unwanted pregnancies after having unprotected intercourse. While 1.5 mg of levonorgestrel (LNG as a single dose or in 2 doses with 12 hours apart is the currently gold standard EC regimen, a single dose of 30 mg ulipristal acetate (UPA has recently been proposed for EC use up to 120 hours of unprotected intercourse with similar side effect profiles as LNG. The main mechanism of action of both LNG and UPA for EC is delaying or inhibiting ovulation. However, the ‘window of effect’ for LNG EC seems to be rather narrow, beginning after selection of the dominant follicular and ending when luteinizing hormone peak begins to rise, whereas UPA appears to have a direct inhibitory effect on follicular rupture which allows it to be also effective even when administered shortly before ovulation, a time period when use of LNG is no longer effective. These experimental findings are in line with results from a series of clinical trials conducted recently which demonstrate that UPA seems to have higher EC efficacy compared to LNG. This review summarizes some of the data available on UPA used after unprotected intercourse with the purpose to provide evidence that UPA, a new type of second-generation progesterone receptor modulator, represents a new evolutionary step in EC treatment.Keywords: emergency contraception, ulipristal acetate, levonorgestrel

  19. Oxidation of indole-3-acetic acid to oxindole-3-acetic acid by an enzyme preparation from Zea mays

    Science.gov (United States)

    Reinecke, D. M.; Bandurski, R. S.

    1988-01-01

    Indole-3-acetic acid is oxidized to oxindole-3-acetic acid by Zea mays tissue extracts. Shoot, root, and endosperm tissues have enzyme activities of 1 to 10 picomoles per hour per milligram protein. The enzyme is heat labile, is soluble, and requires oxygen for activity. Cofactors of mixed function oxygenase, peroxidase, and intermolecular dioxygenase are not stimulatory to enzymic activity. A heat-stable, detergent-extractable component from corn enhances enzyme activity 6- to 10-fold. This is the first demonstration of the in vitro enzymic oxidation of indole-3-acetic acid to oxindole-3-acetic acid in higher plants.

  20. Liquid-Liquid equilibria of the water-acetic acid-butyl acetate system

    Directory of Open Access Journals (Sweden)

    E. Ince

    2002-04-01

    Full Text Available Experimental liquid-liquid equilibria of the water-acetic acid-butyl acetate system were studied at temperatures of 298.15± 0.20, 303.15± 0.20 and 308.15± 0.20 K. Complete phase diagrams were obtained by determining solubility and tie-line data. The reliability of the experimental tie-line data was ascertained by using the Othmer and Tobias correlation. The UNIFAC group contribution method was used to predict the observed ternary liquid-liquid equilibrium (LLE data. It was found that UNIFAC group interaction parameters used for LLE did not provide a good prediction. Distribution coefficients and separation factors were evaluated for the immiscibility region.

  1. A double-blind placebo controlled trial of medroxyprogesterone acetate and cyproterone acetate with seven pedophiles.

    Science.gov (United States)

    Cooper, A J; Sandhu, S; Losztyn, S; Cernovsky, Z

    1992-12-01

    Seven of ten pedophiles in hospital completed a double-blind, placebo-controlled two-dose comparison of medroxyprogesterone acetate and cyproterone acetate. Sequential measures during the 28 week study were: patient self-reports, nurses' observations, phallometry, hormone levels and side-effects. The drugs, which performed equivalently, reduced sexual thoughts and fantasies, the frequency of early morning erections on awakening, the frequency and pleasure of masturbation, and level of sexual frustration. Penile responses were also reduced but to a lesser degree and were more variable. Serum testosterone FSH and LH all declined during drug administration, but by the end of the final placebo phase had essentially returned to (or exceeded) pre-drug values. Our experience suggests that only a minority of pedophiles are likely to accept libido-reducing drugs.

  2. Acetalization of furfural with zeolites under benign reaction conditions

    DEFF Research Database (Denmark)

    Rubio-Caballeroa, Juan Miguel; Shunmugavel, Saravanamurugan; Maireles-Torres, Pedro

    2014-01-01

    Acetalization is a viable method to protect carbonyl functionalities in organic compounds and offers apotential synthetic strategy for synthesizing derived chemicals. In this work, several families of commer-cial zeolites have been employed as solid acid catalysts in the acetalization of furfural...

  3. A review of the animal pharmacology of roxatidine acetate.

    Science.gov (United States)

    Scholtholt, J; Bickel, M; Herling, A W

    1988-01-01

    Roxatidine acetate (TZU 0460/HOE 760) [N-(3-[3-(1-piperidinylmethyl)-phenoxy]-propyl)acetoxyacetamide hydrochloride] is a specific and competitive H2-receptor antagonist with a chemical structure different from those of cimetidine, ranitidine and famotidine. Roxatidine acetate and its main metabolite roxatidine inhibit histamine-induced gastric acid secretion in vitro with a potency greater than that of cimetidine, and in the range of that produced by ranitidine. Gastric acid secretion following stimulation with dibutyryl cyclic adenosine monophosphate remains unaffected by roxatidine acetate. In vivo experiments in rats and dogs confirm these in vitro findings. Thus, in rats roxatidine acetate inhibits gastric acid secretion with similar values following intraduodenal or intraperitoneal injection, indicating excellent absorption of the drug from the gastrointestinal tract. In all studies it was shown that roxatidine acetate was more potent than cimetidine. In rats single or repeated dosing with roxatidine acetate did not influence drug metabolising enzymes in the liver nor did the drug show antiandrogenic activity in long term animal studies. Extensive general pharmacological studies with roxatidine acetate demonstrate the lack of effects on the central nervous system, on gastrointestinal motility, the autonomic nervous system and the cardiovascular and urogenital systems. Studies on the pharmacokinetics and metabolism of roxatidine acetate demonstrate that there is a presystemic deacetylation producing the main metabolite roxatidine, which is responsible for the in vivo effects of the drug.

  4. 21 CFR 522.2477 - Trenbolone acetate and estradiol.

    Science.gov (United States)

    2010-04-01

    ... acetate and 4 mg estradiol, and 1 pellet containing 29 mg tylosin tartrate) per implant dose. (C) 200 mg... containing 29 mg tylosin tartrate) per implant dose. (F) 80 mg trenbolone acetate and 16 mg estradiol (one..., and 1 pellet containing 29 mg tylosin tartrate) per implant dose. (G) 200 milligram (mg)...

  5. Trehalose accumulation enhances tolerance of Saccharomyces cerevisiae to acetic acid.

    Science.gov (United States)

    Yoshiyama, Yoko; Tanaka, Koichi; Yoshiyama, Kohei; Hibi, Makoto; Ogawa, Jun; Shima, Jun

    2015-02-01

    Trehalose confers protection against various environmental stresses on yeast cells. In this study, trehalase gene deletion mutants that accumulate trehalose at high levels showed significant stress tolerance to acetic acid. The enhancement of trehalose accumulation can thus be considered a target in the breeding of acetic acid-tolerant yeast strains.

  6. Acetic acid assisted cobalt methanesulfonate catalysed chemoselective diacetylation of aldehydes

    Institute of Scientific and Technical Information of China (English)

    Min Wang; Zhi Guo Song; Hong Gong; Heng Jiang

    2008-01-01

    Cobalt methanesulfonate in combination with acetic acid catalysed the chemoselective diacetylation of aldehyde with acetic anhydride at room temperature under solvent free conditions. After reaction, cobalt methanesulfonate can be easily recovered and mused many times. The reaction was mild and efficient with good to high yields.

  7. Fermentation of lignocellulosic sugars to acetic acid by Moorella thermoacetica.

    Science.gov (United States)

    Ehsanipour, Mandana; Suko, Azra Vajzovic; Bura, Renata

    2016-06-01

    A systematic study of bioconversion of lignocellulosic sugars to acetic acid by Moorella thermoacetica (strain ATCC 39073) was conducted. Four different water-soluble fractions (hydrolysates) obtained after steam pretreatment of lignocellulosic biomass were selected and fermented to acetic acid in batch fermentations. M. thermoacetica can effectively ferment xylose and glucose in hydrolysates from wheat straw, forest residues, switchgrass, and sugarcane straw to acetic acid. Xylose and glucose were completely utilized, with xylose being consumed first. M. thermoacetica consumed up to 62 % of arabinose, 49 % galactose and 66 % of mannose within 72 h of fermentation in the mixture of lignocellulosic sugars. The highest acetic acid yield was obtained from sugarcane straw hydrolysate, with 71 % of theoretical yield based on total sugars (17 g/L acetic acid from 24 g/L total sugars). The lowest acetic acid yield was observed in forest residues hydrolysate, with 39 % of theoretical yield based on total sugars (18 g/L acetic acid from 49 g/L total sugars). Process derived compounds from steam explosion pretreatment, including 5-hydroxymethylfurfural (0.4 g/L), furfural (0.1 g/L) and total phenolics (3 g/L), did not inhibit microbial growth and acetic acid production yield. This research identified two major factors that adversely affected acetic acid yield in all hydrolysates, especially in forest residues: (i) glucose to xylose ratio and (ii) incomplete consumption of arabinose, galactose and mannose. For efficient bioconversion of lignocellulosic sugars to acetic acid, it is imperative to have an appropriate balance of sugars in a hydrolysate. Hence, the choice of lignocellulosic biomass and steam pretreatment design are fundamental steps for the industrial application of this process.

  8. Measurement of the rates of oxindole-3-acetic acid turnover, and indole-3-acetic acid oxidation in Zea mays seedlings

    Science.gov (United States)

    Nonhebel, H. M.; Bandurski, R. S. (Principal Investigator)

    1986-01-01

    Oxindole-3-acetic acid is the principal catabolite of indole-3-acetic acid in Zea mays seedlings. In this paper measurements of the turnover of oxindole-3-acetic acid are presented and used to calculate the rate of indole-3-acetic acid oxidation. [3H]Oxindole-3-acetic acid was applied to the endosperm of Zea mays seedlings and allowed to equilibrate for 24 h before the start of the experiment. The subsequent decrease in its specific activity was used to calculate the turnover rate. The average half-life of oxindole-3-acetic acid in the shoots was found to be 30 h while that in the kernels had an average half-life of 35h. Using previously published values of the pool sizes of oxindole-3-acetic acid in shoots and kernels from seedlings of the same age and variety, and grown under the same conditions, the rate of indole-3-acetic acid oxidation was calculated to be 1.1 pmol plant-1 h-1 in the shoots and 7.1 pmol plant-1 h-1 in the kernels.

  9. The effect of oral sodium acetate administration on plasma acetate concentration and acid-base state in horses

    Directory of Open Access Journals (Sweden)

    Lindinger Michael I

    2007-12-01

    Full Text Available Abstract Aim Sodium acetate (NaAcetate has received some attention as an alkalinizing agent and possible alternative energy source for the horse, however the effects of oral administration remain largely unknown. The present study used the physicochemical approach to characterize the changes in acid-base status occurring after oral NaAcetate/acetic acid (NAA administration in horses. Methods Jugular venous blood was sampled from 9 exercise-conditioned horses on 2 separate occasions, at rest and for 24 h following a competition exercise test (CET designed to simulate the speed and endurance test of 3-day event. Immediately after the CETs horses were allowed water ad libitum and either: 1 8 L of a hypertonic NaAcetate/acetic acid solution via nasogastric tube followed by a typical hay/grain meal (NAA trial; or 2 a hay/grain meal alone (Control trial. Results Oral NAA resulted in a profound plasma alkalosis marked by decreased plasma [H+] and increased plasma [TCO2] and [HCO3-] compared to Control. The primary contributor to the plasma alkalosis was an increased [SID], as a result of increased plasma [Na+] and decreased plasma [Cl-]. An increased [Atot], due to increased [PP] and a sustained increase in plasma [acetate], contributed a minor acidifying effect. Conclusion It is concluded that oral NaAcetate could be used as both an alkalinizing agent and an alternative energy source in the horse.

  10. 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...

  11. Biological Function of Acetic Acid-Improvement in Obesity and Glucose Tolerance by Acetic Acid in Type 2 Diabetic Rats.

    Science.gov (United States)

    Yamashita, Hiromi

    2016-07-29

    Fatty acids derived from adipose tissue are oxidized by β-oxidation to form ketone bodies as final products under the starving condition. Previously, we found that free acetic acid was formed concomitantly with the production of ketone bodies in isolated rat liver perfusion, and mitochondrial acetyl CoA hydrolase was appeared to be involved with the acetic acid production. It was revealed that acetic acid was formed as a final product of enhanced β-oxidation of fatty acids and utilized as a fuel in extrahepatic tissues under the starving condition. Under the fed condition, β-oxidation is suppressed and acetic acid production is decreased. When acetic acid was taken daily by obesity-linked type 2 diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats under the fed condition, it protected OLETF rats against obesity. Furthermore, acetic acid contributed to protect from the accumulation of lipid in the liver as well as abdominal fat in OLETF rats. Transcripts of lipogenic genes in the liver were decreased, while transcripts of myoglobin and Glut4 genes in abdominal muscles were increased in the acetic acid-administered OLETF rats. It is indicated that exogenously administered acetic acid would have effects on lipid metabolism in both the liver and the skeletal muscles, and have function that works against obesity and obesity-linked type 2 diabetes.

  12. Hydrolyses of alpha-naphthyl acetate, beta-naphthyl acetate, and acetyl-DL-phenylalanine beta-naphthyl ester

    DEFF Research Database (Denmark)

    Kirkeby, S; Moe, D

    1983-01-01

    Using simultaneous coupling azo dye techniques kidney enzymes active against alpha-naphthyl acetate, beta-naphthyl acetate, and acetyl-DL-phenylalanine beta-naphthyl ester are characterized. The enzymes show identical distribution in the section. The banding patterns in zymograms are the same after...

  13. Oxidation of indole-3-acetic acid and oxindole-3-acetic acid to 2,3-dihydro-7-hydroxy-2-oxo-1H indole-3-acetic acid-7'-O-beta-D-glucopyranoside in Zea mays seedlings

    Science.gov (United States)

    Nonhebel, H. M.; Bandurski, R. S.

    1984-01-01

    Radiolabeled oxindole-3-acetic acid was metabolized by roots, shoots, and caryopses of dark grown Zea mays seedlings to 2,3-dihydro-7-hydroxy-2-oxo-1H indole-3-acetic acid-7'-O-beta-D-glycopyranoside with the simpler name of 7-hydroxyoxindole-3-acetic acid-glucoside. This compound was also formed from labeled indole-3-acetic acid supplied to intact seedlings and root segments. The glucoside of 7-hydroxyoxindole-3-acetic acid was also isolated as an endogenous compound in the caryopses and shoots of 4-day-old seedlings. It accumulates to a level of 4.8 nanomoles per plant in the kernel, more than 10 times the amount of oxindole-3-acetic acid. In the shoot it is present at levels comparable to that of oxindole-3-acetic acid and indole-3-acetic acid (62 picomoles per shoot). We conclude that 7-hydroxyoxindole-3-acetic acid-glucoside is a natural metabolite of indole-3-acetic acid in Z. mays seedlings. From the data presented in this paper and in previous work, we propose the following route as the principal catabolic pathway for indole-3-acetic acid in Zea seedlings: Indole-3-acetic acid --> Oxindole-3-acetic acid --> 7-Hydroxyoxindole-3-acetic acid --> 7-Hydroxyoxindole-3-acetic acid-glucoside.

  14. Quantitative Structure of an Acetate Dye Molecule Analogue at the TiO2–Acetic Acid Interface

    Science.gov (United States)

    2016-01-01

    The positions of atoms in and around acetate molecules at the rutile TiO2(110) interface with 0.1 M acetic acid have been determined with a precision of ±0.05 Å. Acetate is used as a surrogate for the carboxylate groups typically employed to anchor monocarboxylate dye molecules to TiO2 in dye-sensitized solar cells (DSSC). Structural analysis reveals small domains of ordered (2 × 1) acetate molecules, with substrate atoms closer to their bulk terminated positions compared to the clean UHV surface. Acetate is found in a bidentate bridge position, binding through both oxygen atoms to two 5-fold titanium atoms such that the molecular plane is along the [001] azimuth. Density functional theory calculations provide adsorption geometries in excellent agreement with experiment. The availability of these structural data will improve the accuracy of charge transport models for DSSC. PMID:27110318

  15. Quantitative Structure of an Acetate Dye Molecule Analogue at the TiO2-Acetic Acid Interface.

    Science.gov (United States)

    Hussain, Hadeel; Torrelles, Xavier; Cabailh, Gregory; Rajput, Parasmani; Lindsay, Robert; Bikondoa, Oier; Tillotson, Marcus; Grau-Crespo, Ricardo; Zegenhagen, Jörg; Thornton, Geoff

    2016-04-14

    The positions of atoms in and around acetate molecules at the rutile TiO2(110) interface with 0.1 M acetic acid have been determined with a precision of ±0.05 Å. Acetate is used as a surrogate for the carboxylate groups typically employed to anchor monocarboxylate dye molecules to TiO2 in dye-sensitized solar cells (DSSC). Structural analysis reveals small domains of ordered (2 × 1) acetate molecules, with substrate atoms closer to their bulk terminated positions compared to the clean UHV surface. Acetate is found in a bidentate bridge position, binding through both oxygen atoms to two 5-fold titanium atoms such that the molecular plane is along the [001] azimuth. Density functional theory calculations provide adsorption geometries in excellent agreement with experiment. The availability of these structural data will improve the accuracy of charge transport models for DSSC.

  16. Simultaneous production of acetic and gluconic acids by a thermotolerant Acetobacter strain during acetous fermentation in a bioreactor.

    Science.gov (United States)

    Mounir, Majid; Shafiei, Rasoul; Zarmehrkhorshid, Raziyeh; Hamouda, Allal; Ismaili Alaoui, Mustapha; Thonart, Philippe

    2016-02-01

    The activity of bacterial strains significantly influences the quality and the taste of vinegar. Previous studies of acetic acid bacteria have primarily focused on the ability of bacterial strains to produce high amounts of acetic acid. However, few studies have examined the production of gluconic acid during acetous fermentation at high temperatures. The production of vinegar at high temperatures by two strains of acetic acid bacteria isolated from apple and cactus fruits, namely AF01 and CV01, respectively, was evaluated in this study. The simultaneous production of gluconic and acetic acids was also examined in this study. Biochemical and molecular identification based on a 16s rDNA sequence analysis confirmed that these strains can be classified as Acetobacter pasteurianus. To assess the ability of the isolated strains to grow and produce acetic acid and gluconic acid at high temperatures, a semi-continuous fermentation was performed in a 20-L bioreactor. The two strains abundantly grew at a high temperature (41°C). At the end of the fermentation, the AF01 and CV01 strains yielded acetic acid concentrations of 7.64% (w/v) and 10.08% (w/v), respectively. Interestingly, CV01 was able to simultaneously produce acetic and gluconic acids during acetic fermentation, whereas AF01 mainly produced acetic acid. In addition, CV01 was less sensitive to ethanol depletion during semi-continuous fermentation. Finally, the enzymatic study showed that the two strains exhibited high ADH and ALDH enzyme activity at 38°C compared with the mesophilic reference strain LMG 1632, which was significantly susceptible to thermal inactivation.

  17. SAGA complex components and acetate repression in Aspergillus nidulans.

    Science.gov (United States)

    Georgakopoulos, Paraskevi; Lockington, Robin A; Kelly, Joan M

    2012-11-01

    Alongside the well-established carbon catabolite repression by glucose and other sugars, acetate causes repression in Aspergillus nidulans. Mutations in creA, encoding the transcriptional repressor involved in glucose repression, also affect acetate repression, but mutations in creB or creC, encoding components of a deubiquitination system, do not. To understand the effects of acetate, we used a mutational screen that was similar to screens that uncovered mutations in creA, creB, and creC, except that glucose was replaced by acetate to identify mutations that were affected for repression by acetate but not by glucose. We uncovered mutations in acdX, homologous to the yeast SAGA component gene SPT8, which in growth tests showed derepression for acetate repression but not for glucose repression. We also made mutations in sptC, homologous to the yeast SAGA component gene SPT3, which showed a similar phenotype. We found that acetate repression is complex, and analysis of facA mutations (lacking acetyl CoA synthetase) indicates that acetate metabolism is required for repression of some systems (proline metabolism) but not for others (acetamide metabolism). Although plate tests indicated that acdX- and sptC-null mutations led to derepressed alcohol dehydrogenase activity, reverse-transcription quantitative real-time polymerase chain reaction showed no derepression of alcA or aldA but rather elevated induced levels. Our results indicate that acetate repression is due to repression via CreA together with metabolic changes rather than due to an independent regulatory control mechanism.

  18. Ethinylestradiol/Chlormadinone acetate: dermatological benefits.

    Science.gov (United States)

    Guerra-Tapia, Aurora; Sancho Pérez, Blanca

    2011-09-06

    Acne vulgaris, hirsutism, seborrhea and female pattern hair loss (FPHL) are common disorders of the pilosebaceous unit (PSU). In some women with hyperandrogenemia, an excess of androgens at the PSU can lead to the development of these dermatological manifestations. These manifestations can cause many psychiatric and psychological implications, such as social fears and anxiety, and can adversely affect quality of life. High androgen levels at the PSU as a possible underlying cause of acne vulgaris, hirsutism, seborrhea and FPHL supports the rationale for using combined oral contraceptives for the management of these conditions in women. The purpose of this review is to describe these dermatological manifestations of the PSU and the management of these conditions through the use of the oral contraceptive ethinylestradiol/chlormadinone acetate (EE/CMA). EE/CMA 0.03/2 mg is a combined monophasic contraceptive pill with anti-androgenic properties. It is approved in Europe for contraception and has been investigated in phase III trials for the treatment of acne. EE/CMA was better than placebo and similar to another low-dose oral contraceptive (ethinylestradiol/levonorgestrel) in improving symptoms of acne in two phase III randomized controlled trials in patients with mild to moderate papulopustular acne. In addition, in trials investigating the contraceptive efficacy of EE/CMA, limited data suggest that there were also improvements in hirsutism, FPHL and seborrhea in small subgroups of patients. EE/CMA has a good safety profile. The most commonly reported adverse events are breast tenderness/pain, headache/migraine and nausea. Evidence in the literature indicates that the use of EE/CMA for the treatment of dermatological disorders under the control of androgens may be a valid treatment option. Further investigation is warranted.

  19. Leuprolide acetate suppresses pedophilic urges and arousability.

    Science.gov (United States)

    Schober, Justine M; Kuhn, Phyllis J; Kovacs, Paul G; Earle, James H; Byrne, Peter M; Fries, Ruth A

    2005-12-01

    Cognitive-behavioral psychotherapy was compared with cognitive-behavioral psychotherapy augmented by leuprolide acetate (LA) for suppression of pedophilic behavior. Five male pedophiles (M age, 50 years; range, 36-58) were administered LA by Depo injection for 12 months, followed by saline placebo for 12 months. Testosterone levels, sexual interest preference by visual reaction time (Abel Assessment), penile tumescence (Monarch Penile Plethysmography, PPG), as well as strong sexual urges toward children and masturbatory frequency involving thoughts of children (polygraph), were measured every 3 months. On LA, testosterone decreased to castrate levels. Penile tumescence was significantly suppressed compared with baseline, but sufficient response remained to detect pedophilic interest. Pedophilic interest was also detected by visual reaction times. When asked about having pedophilic urges and masturbating to thoughts of children, all subjects self-reported a decrease. Polygraph responses indicated subjects were not deceptive. On placebo, testosterone and physiologic arousal eventually rose to baseline. As noted by polygraph, at baseline and on placebo, subjects were deceptive regarding increased pedophilic urges and masturbatory frequency. Interest preference, as measured by Abel Assessment and Monarch PPG, was generally unchanged throughout the study. Cognitive-behavioral psychotherapy augmented with LA significantly reduced pedophilic fantasies, urges, and masturbation; however, pedophilic interest did not change during 1 year of therapy. Deceptive responses by polygraph suggested that self-report was unreliable. Follow-up utilizing objective measures is essential for monitoring efficacy of treatment in pedophilia. Our study supports the premise that suppression of pedophilic behavior is possible. LA may augment cognitive-behavioral psychotherapy and help break the sequence leading to a re-offense.

  20. Inhibition of ice growth and recrystallization by zirconium acetate and zirconium acetate hydroxide.

    Directory of Open Access Journals (Sweden)

    Ortal Mizrahy

    Full Text Available The control over ice crystal growth, melting, and shaping is important in a variety of fields, including cell and food preservation and ice templating for the production of composite materials. Control over ice growth remains a challenge in industry, and the demand for new cryoprotectants is high. Naturally occurring cryoprotectants, such as antifreeze proteins (AFPs, present one solution for modulating ice crystal growth; however, the production of AFPs is expensive and inefficient. These obstacles can be overcome by identifying synthetic substitutes with similar AFP properties. Zirconium acetate (ZRA was recently found to induce the formation of hexagonal cavities in materials prepared by ice templating. Here, we continue this line of study and examine the effects of ZRA and a related compound, zirconium acetate hydroxide (ZRAH, on ice growth, shaping, and recrystallization. We found that the growth rate of ice crystals was significantly reduced in the presence of ZRA and ZRAH, and that solutions containing these compounds display a small degree of thermal hysteresis, depending on the solution pH. The compounds were found to inhibit recrystallization in a manner similar to that observed in the presence of AFPs. The favorable properties of ZRA and ZRAH suggest tremendous potential utility in industrial applications.

  1. Disproportionation Kinetics of Hypoiodous Acid As Catalyzed and Suppressed by Acetic Acid-Acetate Buffer.

    Science.gov (United States)

    Urbansky, Edward T.; Cooper, Brian T.; Margerum, Dale W.

    1997-03-26

    The kinetics of the disproportionation of hypoiodous acid to give iodine and iodate ion (5HOI right harpoon over left harpoon 2I(2) + IO(3)(-) + H(+) + 2H(2)O) are investigated in aqueous acetic acid-sodium acetate buffer. The rate of iodine formation is followed photometrically at -log [H(+)] = 3.50, 4.00, 4.50, and 5.00, &mgr; = 0.50 M (NaClO(4)), and 25.0 degrees C. Both catalytic and inhibitory buffer effects are observed. The first process is proposed to be a disproportionation of iodine(I) to give HOIO and I(-); the iodide then reacts with HOI to give I(2). The reactive species (acetato-O)iodine(I), CH(3)CO(2)I, is postulated to increase the rate by assisting in the formation of I(2)O, a steady-state species that hydrolyzes to give HOIO and I(2). Inhibition is postulated to result from the formation of the stable ion bis(acetato-O)iodate(I), (CH(3)CO(2))(2)I(-), as buffer concentration is increased. This species is observed spectrophotometrically with a UV absorption shoulder (lambda = 266 nm; epsilon = 530 M(-)(1) cm(-)(1)). The second process is proposed to be a disproportionation of HOIO to give IO(3)(-) and I(2). Above 1 M total buffer, the reaction becomes reversible with less than 90% I(2) formation. Rate and equilibrium constants are resolved and reported for the proposed mechanism.

  2. Inhibition of ice growth and recrystallization by zirconium acetate and zirconium acetate hydroxide.

    Science.gov (United States)

    Mizrahy, Ortal; Bar-Dolev, Maya; Guy, Shlomit; Braslavsky, Ido

    2013-01-01

    The control over ice crystal growth, melting, and shaping is important in a variety of fields, including cell and food preservation and ice templating for the production of composite materials. Control over ice growth remains a challenge in industry, and the demand for new cryoprotectants is high. Naturally occurring cryoprotectants, such as antifreeze proteins (AFPs), present one solution for modulating ice crystal growth; however, the production of AFPs is expensive and inefficient. These obstacles can be overcome by identifying synthetic substitutes with similar AFP properties. Zirconium acetate (ZRA) was recently found to induce the formation of hexagonal cavities in materials prepared by ice templating. Here, we continue this line of study and examine the effects of ZRA and a related compound, zirconium acetate hydroxide (ZRAH), on ice growth, shaping, and recrystallization. We found that the growth rate of ice crystals was significantly reduced in the presence of ZRA and ZRAH, and that solutions containing these compounds display a small degree of thermal hysteresis, depending on the solution pH. The compounds were found to inhibit recrystallization in a manner similar to that observed in the presence of AFPs. The favorable properties of ZRA and ZRAH suggest tremendous potential utility in industrial applications.

  3. KINETIC STUDY OF CARBONYLATION OF METHANOL TO ACETIC ACID AND ACETIC ANHYDRIDE OVER A NOVEL COPOLYMER- BOUND CIS- DICARBONYLRHODIUM COMPLEX

    Institute of Scientific and Technical Information of China (English)

    CHEN Yuying; YUAN Guoqing; CHEN Rongyao

    1989-01-01

    The kinetic study of carbonylation of methanol-acetic acid mixture to acetic acid and acetic anhydride over a cis-dicarbonylrhodium complex (MVM' Rh)coordinated with the ethylene diacrylate (M')crosslinked copolymer of methyl acrylate (M) and 2 - vinylpyridine (V) shows that the rate of reaction is zero order with respect to both reactants methanol and carbon monoxide, but first order in the concentrations of promoter methyl iodide and rhodium in the complex . Polar solvents can accelerate the reaction .Activation parameters were calculated from the experimental results, being comparable to that of the homogeneous system . A mechanism similar to that of soluble rhodium catalyst was proposed .

  4. Measurement and modelization of VLE of binary mixtures of propyl acetate, butyl acetate or isobutyl acetate with methanol at pressure of 0.6 MPa

    Institute of Scientific and Technical Information of China (English)

    P Susial; D Garca; R Susial; YC Clavijo; A Martn

    2016-01-01

    The vapor–liquid equilibrium of binary mixtures of propyl acetate, butyl acetate and isobutyl acetate with meth-anol has been determined at a constant pressure of 0.6 MPa. Results have been modeled with the Peng–Robinson equation, a traditional cubic equation of state widely employed in chemical industries, as well as with the perturbed-chain statistical associating fluid PC-SAFT theory of Gross–Sadowski. By correlation of the binary inter-action parameters of these equations, the measured vapor–liquid equilibrium data can be accurately predicted. Thus, this work shows that these models are able to represent the experimental data for systems with associating compounds via hydrogen bonding.

  5. Densities, speeds of sound, and refractive indices of the ternary mixtures (toluene + methyl acetate + butyl acetate) and (toluene + methyl acetate + methyl heptanoate) at 298.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Mariano, Alejandra [Departamento de Quimica, Facultad de Ingenieria, Universidad Nacional del Comahue, Buenos Aires 1400 (8300) Neuquen (Argentina); Postigo, Miguel [Departamento de Quimica, Facultad de Ingenieria, Universidad Nacional del Comahue, Buenos Aires 1400 (8300) Neuquen (Argentina)]. E-mail: postigo@uncoma.edu.ar; Gonzalez-Salgado, Diego [Departamento de Fisica Aplicada, Universidad de Vigo, Facultad de Ciencias del Campus de Ourense, E 32004 Ourense (Spain); Romani, Luis [Departamento de Fisica Aplicada, Universidad de Vigo, Facultad de Ciencias del Campus de Ourense, E 32004 Ourense (Spain)

    2007-02-15

    Density, {rho}, speed of sound, u, and refractive index, n {sub D}, at 298.15 K and atmospheric pressure have been measured over the entire composition range for (toluene + methyl acetate + butyl acetate) and (toluene + methyl acetate + methyl heptanoate) systems. Excess molar volumes, V {sup E}, isentropic compressibility, {kappa} {sub s}, isentropic compressibility deviations, {delta}{kappa} {sub s}, and changes of refractive index on mixing, {delta}n {sub D}, for the above systems, have been calculated from experimental data and fitted to Cibulka, Singh et al., and Nagata and Sakura equations, standard deviations from the regression lines are shown. Geometrical solution models, Tsao and Smith, Kholer, Jacob and Fitzner, Rastogi et al. were also applied to predict ternary properties from binary contributions.

  6. Ammonia effect on hydrogenotrophic methanogens and syntrophic acetate oxidizing bacteria

    DEFF Research Database (Denmark)

    Wang, Han; Fotidis, Ioannis; Angelidaki, Irini

    2015-01-01

    Ammonia-rich substrates can cause inhibition on anaerobic digestion process. Syntrophic acetate oxidizing bacteria (SAOB) and hydrogenotrophic methanogens are important for the ammonia inhibitory mechanism on anaerobic digestion. The roles and interactions of SAOB and hydrogenotrophic methanogens...

  7. CHARACTERIZATION OF REGENERATED CELLULOSE MEMBRANES HYDROLYZED FROM CELLULOSE ACETATE

    Institute of Scientific and Technical Information of China (English)

    Yun Chen; Xiao-peng Xiong; Guang Yang; Li-na Zhang; Sen-lin Lei; Hui Lianga

    2002-01-01

    A series of cellulose acetate membranes were prepared by using formamide as additive, and then were hydrolyzedin 4 wt% aqueous NaOH solution for 8 h to obtain regenerated cellulose membranes. The dependence of degree ofsubstitution, structure, porous properties, solubility and thermal stability on hydrolysis time was studied by chemical titration,Fourier transform infrared spectroscopy, scanning electron microscopy, wide-angle X-ray diffraction, and differentialscanning calorimetry, respectively. The results indicated that the pore size of the regenerated cellulose membranes wasslightly smaller than that of cellulose acetate membrane, while solvent-resistance, crystallinity and thermostability weresignificantly improved. This work provides a simple way to prepare the porous cellulose membranes, which not only kept thegood pore characteristics of cellulose acetate membranes, but also possessed solvent-resistance, high crystallinity andthermostability. Therefore, the application range of cellulose acetate membranes can be expanded.

  8. EFFECT OF COLD EXPOSURE AND FASTING ON HEPATIC ACETATE METABOLISM

    Science.gov (United States)

    present investigation the carbohydrate content of the liver was drastically reduced by fasting rats both at 25 C. and 0 C. Acetate oxidation is greatly depressed by the lowering of the hepatic carbohydrate level. (Author)

  9. Catalytic Esterification of Methyl Alcohol with Acetic Acid

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Esterification of methyl alcohol with acetic acid catalysed by Amberlyst-15 (cation-exchange resin) was carried out in a batch reactor in the temperature ranging between 318-338 K, at atmospheric pressure. The reaction rate increased with increase in catalyst concentration and reaction temperature, but decreased with an increase in water concentration. Stirrer speed had virtually no effect on the rate under the experimental conditions. The rate data were correlated with a second-order kinetic model based on homogeneous reaction. The apparent activation energy was found to be 22.9kJ.mo1-1 for the formation of methyl acetate. The methyl acetate production was carried out aa batch and continuous in a packed bed restive distillation column with high purity methyl acetate produced.

  10. Probiotic and Acetic Acid Effect on Broiler Chickens Performance

    OpenAIRE

    Martin Král; Mária Angelovičová; Ľubica Mrázová; Jana Tkáčová; Martin Kliment

    2011-01-01

    Probiotics and organic acids are widely accepted as an alternative to in-feed antibiotics in poultry production. We carried the experiment with broiler chickens. In experiment we research effect of probiotic and acetic acids on the performance of broiler chickens. A total number of 200 one day old broiler chickens were distributed to two dietary groups. Broiler chickens in control group were fed with standard feed mixture and experimental group 1% vinegar contained 5% acetic acid used in drin...

  11. Proteome analysis of Acetobacter pasteurianus during acetic acid fermentation.

    Science.gov (United States)

    Andrés-Barrao, Cristina; Saad, Maged M; Chappuis, Marie-Louise; Boffa, Mauro; Perret, Xavier; Ortega Pérez, Ruben; Barja, François

    2012-03-16

    Acetic acid bacteria (AAB) are Gram-negative, strictly aerobic microorganisms that show a unique resistance to ethanol (EtOH) and acetic acid (AcH). Members of the Acetobacter and Gluconacetobacter genera are capable of transforming EtOH into AcH via the alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) enzymes and are used for the industrial production of vinegar. Several mechanisms have been proposed to explain how AAB resist high concentrations of AcH, such as the assimilation of acetate through the tricarboxylic acid (TCA) cycle, the export of acetate by various transporters and modifications of the outer membrane. However, except for a few acetate-specific proteins, little is known about the global proteome responses to AcH. In this study, we used 2D-DIGE to compare the proteome of Acetobacter pasteurianus LMG 1262(T) when growing in glucose or ethanol and in the presence of acetic acid. Interesting protein spots were selected using the ANOVA p-value of 0.05 as threshold and 1.5-fold as the minimal level of differential expression, and a total of 53 proteins were successfully identified. Additionally, the size of AAB was reduced by approximately 30% in length as a consequence of the acidity. A modification in the membrane polysaccharides was also revealed by PATAg specific staining.

  12. Genetic organization of Acetobacter for acetic acid fermentation.

    Science.gov (United States)

    Beppu, T

    Plasmid vectors for the acetic acid-producing strains of Acetobacter and Gluconobacter were constructed from their cryptic plasmids and the efficient transformation conditions were established. The systems allowed to reveal the genetic background of the strains used in the acetic acid fermentation. Genes encoding indispensable components in the acetic acid fermentation, such as alcohol dehydrogenase, aldehyde dehydrogenase and terminal oxidase, were cloned and characterized. Spontaneous mutations at high frequencies in the acetic acid bacteria to cause the deficiency in ethanol oxidation were analyzed. A new insertion sequence element, IS1380, was identified as a major factor of the genetic instability, which causes insertional inactivation of the gene encoding cytochrome c, an essential component of the functional alcohol dehydrogenase complex. Several genes including the citrate synthase gene of A. aceti were identified to confer acetic acid resistance, and the histidinolphosphate aminotransferase gene was cloned as a multicopy suppressor of an ethanol sensitive mutant. Improvement of the acetic acid productivity of an A. aceti strain was achieved through amplification of the aldehyde dehydrogenase gene with a multicopy vector. In addition, spheroplast fusion of the Acetobacter strains was developed and applied to improve their properties.

  13. The Solubility Rules: Why Are All Acetates Soluble?

    Science.gov (United States)

    van der Sluys, William G.

    2001-01-01

    According to the solubility rules presented in many introductory chemistry texts, all (or most) acetate salts are soluble in aqueous solution. The thermodynamic factors that contribute to the solubility of acetates are compared with those of other slightly basic anions. In particular, the hydration enthalpy of acetate is calculated using the Born-Haber approach, from lattice energies, heats of solution, and the hydration energies of several cations. The hydration enthalpy of acetate (-375 kJ/mol) is similar to that of chloride ({355 kJ/mol), nitrite ({383 kJ/mol), and nitrate ({370 kJ/mol), which are all considerably less exothermic than fluoride ({497 kJ/mol). This was somewhat unexpected, since hydration enthalpies generally correlate well with the acid-base properties of an ion, and acetate is more basic than fluoride. Factors influencing the solubility and acid-base properties of acetates, such as the electron donating and hydrophobic nature of the methyl group, are discussed in light of the thermodynamic data.

  14. Laboratory millimeter wave spectrum and astronomical search for vinyl acetate

    Science.gov (United States)

    Kolesniková, L.; Peña, I.; Alonso, J. L.; Cernicharo, J.; Tercero, B.; Kleiner, I.

    2015-05-01

    Context. The recent discovery of methyl acetate in Orion KL makes vinyl acetate, CH3C=OOCH=CH2, a potential molecule in the interstellar medium. We obtained very accurate spectroscopic constants in a comprehensive laboratory analysis of its rotational spectra which can be used to predict those transition frequencies towards interstellar sources. Aims: We present the experimental study and theoretical analysis of the ground torsional state of vinyl acetate in a large spectral range for astrophysical use. Methods: The room-temperature rotational spectrum of vinyl acetate has been measured from 125 to 305 GHz to provide direct frequencies to the astronomical community. Additional measurements have also been made using a broadband CP-FTMW spectrometer in the region of 6-18 GHz. Transition lines, corresponding to the most stable conformer, have been observed and assigned. All the rotational transitions revealed the A-E splitting due to the methyl internal rotation and had to be treated with a specific internal rotation code (BELGI-Cs). Results: We analyzed 2508 transitions up to J'' = 75 for vt = 0 for the most stable conformer of vinyl acetate. The new lines were globally fitted with previously published data and 24 parameters of the Hamiltonian were accurately determined. The spectral features of vinyl acetate were then searched for in Orion KL. Using the whole line survey of Orion KL (80-280 GHz) obtained with the IRAM 30 m radio telescope we can provide only an upper limit to the column density of vinyl acetate. However, using the ALMA science verification data we obtain a tentative detection of this species that will require further search at other frequencies to confirm its presence in this high mass star forming region. Table 2 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/577/A91

  15. 21 CFR 177.1360 - Ethylene-vinyl acetate-vinyl alcohol copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-vinyl acetate-vinyl alcohol copolymers... acetate-vinyl alcohol copolymers. Ethylene-vinyl acetate-vinyl alcohol copolymers (CAS Reg. No. 26221-27-2... accordance with the following prescribed conditions: (a) Ethylene-vinyl acetate-vinyl alcohol copolymers...

  16. Hydrogen production by fermentation using acetic acid and lactic acid.

    Science.gov (United States)

    Matsumoto, Mitsufumi; Nishimura, Yasuhiko

    2007-03-01

    Microbial hydrogen production from sho-chu post-distillation slurry solution (slurry solution) containing large amounts of organic acids was investigated. The highest hydrogen producer, Clostridium diolis JPCC H-3, was isolated from natural environment and produced hydrogen at 6.03+/-0.15 ml from 5 ml slurry solution in 30 h. Interestingly, the concentration of acetic acid and lactic acid in the slurry solution decreased during hydrogen production. The substrates for hydrogen production by C. diolis JPCC H-3, in particular organic acids, were investigated in an artificial medium. No hydrogen was produced from acetic acid, propionic acid, succinic acid, or citric acid on their own. Hydrogen and butyric acid were produced from a mixture of acetic acid and lactic acid, showing that C. diolis. JPCC H-3 could produce hydrogen from acetic acid and lactic acid. Furthermore, calculation of the Gibbs free energy strongly suggests that this reaction would proceed. In this paper, we describe for the first time microbial hydrogen production from acetic acid and lactic acid by fermentation.

  17. Leuprorelin Acetate in Prostate Cancer: a European Update

    Directory of Open Access Journals (Sweden)

    Persad R

    2002-01-01

    Full Text Available This review provides an update on leuprorelin acetate, the world's most widely prescribed depot luteinising hormone-releasing hormone analogue. Leuprorelin acetate has been in clinical use in the palliative treatment of prostate cancer for more than 20 years, but advances continue to be made in terms of convenience and flexibility of administration, and in the incorporation of leuprorelin acetate into novel treatment regimens. The drug is administered in the form of a depot injection containing leuprorelin acetate microspheres, and is at least as effective in suppressing testosterone secretion as orchiectomy. In patients with prostate cancer, serum testosterone levels are reduced to castrate levels (= 50 ng/dl within 2-3 weeks of the first one-month depot injection of 3.75 mg or three-month depot injection of 11.25 mg. Both the one-month and three-month formulations are effective in delaying tumour progression and alleviating symptoms of locally advanced and metastatic prostate cancer. Tolerability is generally good, with side-effects reflecting effective testosterone suppression. Recent studies have investigated the place of leuprorelin acetate as part of continuous or intermittent maximal androgen blockade (MAB and in neoadjuvant therapy (ie, to reduce the size of the prostate and downsize the tumour before radiotherapy. Additional formulations and presentations are in development, including a six-month injection, with the aim of adding to the clinical flexibility and patient acceptability of this important palliative treatment for prostate cancer.

  18. [Conversion of acetic acid to methane by thermophiles: Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Zinder, S.

    1991-12-31

    The objective of this project is to provide an understanding of thermophilic anaerobic microorganisms capable of breaking down acetic acid, the precursor of two-thirds of the methane produced by anaerobic bioreactors. Recent results include: (1) the isolation of Methanothrix strain CALLS-1, which grows much more rapidly than mesophilic strains; (2) the demonstration that thermophilic cultures of Methanosarcina and Methanothrix show minimum thresholds for acetate utilization of 1--2.5 mM and 10--20{mu}m respectively, in agreement with ecological data indicating that Methanothrix is favored by low acetate concentration; (3) the demonstration of high levels of thermostable acetyl-coA synthetase and carbon monoxide dehydrogenase in cell-free extracts of Methanothrix strains CALS-1; (4) the demonstration of methanogenesis from acetate and ATP in cell free extracts of strain CALS-1. (5) the demonstration that methanogenesis from acetate required 2 ATP/methane, and, in contrast to Methanosarcina, was independent of hydrogen and other electron donors; (6) the finding that entropy effects must be considered when predicting the level of hydrogen in thermophilic syntrophic cultures. (7) the isolation and characterization of the Desulfotomaculum thermoacetoxidans. Current research is centered on factors which allow thermophilic Methanothrix to compete with Methanosarcina.

  19. (Conversion of acetic acid to methane by thermophiles: Progress report)

    Energy Technology Data Exchange (ETDEWEB)

    Zinder, S.

    1991-01-01

    The objective of this project is to provide an understanding of thermophilic anaerobic microorganisms capable of breaking down acetic acid, the precursor of two-thirds of the methane produced by anaerobic bioreactors. Recent results include: (1) the isolation of Methanothrix strain CALLS-1, which grows much more rapidly than mesophilic strains; (2) the demonstration that thermophilic cultures of Methanosarcina and Methanothrix show minimum thresholds for acetate utilization of 1--2.5 mM and 10--20{mu}m respectively, in agreement with ecological data indicating that Methanothrix is favored by low acetate concentration; (3) the demonstration of high levels of thermostable acetyl-coA synthetase and carbon monoxide dehydrogenase in cell-free extracts of Methanothrix strains CALS-1; (4) the demonstration of methanogenesis from acetate and ATP in cell free extracts of strain CALS-1. (5) the demonstration that methanogenesis from acetate required 2 ATP/methane, and, in contrast to Methanosarcina, was independent of hydrogen and other electron donors; (6) the finding that entropy effects must be considered when predicting the level of hydrogen in thermophilic syntrophic cultures. (7) the isolation and characterization of the Desulfotomaculum thermoacetoxidans. Current research is centered on factors which allow thermophilic Methanothrix to compete with Methanosarcina.

  20. Adiabatic calorimetry (RSST and VSP) tests with sodium acetate

    Energy Technology Data Exchange (ETDEWEB)

    Kirch, N.W.

    1993-09-01

    As requested in the subject reference, adiabatic calorimetry (RSST and VSP) tests have been performed with sodium acetate covering TOC concentrations from 3 to 7% with the following results: Exothermic activity noted around 200{degrees}C. Propagating reaction initiated at about 300{degrees}C. Required TOC concentration for propagation estimated at about 6 w% (dry mixture) or about 20 w% sodium acetate. Heat of reaction estimated to be 3.7 MJ per kg of sodium acetate (based on VSP test with 3 w% TOC and using a dry mixture specific heat of 1000 J kg{sup {minus}1} K{sup {minus}1}). Based upon the above results we estimate that a moisture content in excess of 14 w% would prevent a propagating reaction of a stoichiometric mixture of fuel and oxidizer ({approximately} 38 w% sodium acetate and {approximately}62 w% sodium nitrate). Assuming that the fuel can be treated as sodium acetate equivalent, and considering that the moisture content in the organic containing waste generally is believed to be in excess of 14 w%, it follows that the possibility of propagating reactions in the Hanford waste tanks can be ruled out.

  1. A comparison of acetate and digital templating for hip resurfacing.

    Science.gov (United States)

    Bracey, Daniel N; Seyler, Thorsten M; Shields, John S; Leng, Xiaoyan; Jinnah, Riyaz H; Lang, Jason E

    2014-01-01

    This study sought to determine whether templating for metal-on-metal hip resurfacing is more accurate with digital or acetate methodology. The medical records of 102 consecutive patients who underwent hip resurfacing at our institution were retrospectively reviewed. Records lacking preoperative radiographs that included a magnification-establishing marker were excluded, leaving 78 records for study. Two investigators independently prepared acetate and digital templates of the preoperative radiographs, which had been calibrated to 120% magnification, to predict femoral and acetabular component size. Accuracy was measured by comparing the predicted component sizes to the surgically implanted component sizes. Digital templating was more accurate than acetate templating in predicting hip resurfacing component size when measuring accuracy of templates by the absolute error of predicted component sizes (femoral, P hip resurfacing procedures.

  2. Kinetics of wet oxidation of formic acid and acetic acid

    Energy Technology Data Exchange (ETDEWEB)

    Shende, R.V.; Mahajani, V.V. [Univ. of Mumbai (India). Dept. of Chemical Technology

    1997-11-01

    Oxidation of lower molecular weight carboxylic acids such as formic, acetic, glyoxalic, and oxalic acids is often the rate-controlling step during wet oxidation (WO) of an aqueous waste stream exhibiting very high chemical oxygen demand (COD). The kinetics of WO of formic acid was studied in the absence and presence of a cupric sulfate as catalyst in the temperature range 150--240 C and oxygen partial pressure range 0.345--1.380 MPa. Wet oxidation of acetic acid was carried out in the presence of cupric sulfate in the temperature range 215--235 C. Homogeneous copper sulfate was found to be a very good catalyst for oxidation of formic acid and acetic acid.

  3. Interaction of roxatidine acetate with antacids, food and other drugs.

    Science.gov (United States)

    Labs, R A

    1988-01-01

    The inhibition of hepatic mixed-function oxidase microsomal enzymes by cimetidine can lead to clinically important drug interactions. The metabolism of antipyrine is used as an index of hepatic enzymatic activity. The pharmacokinetic profiles of salivary antipyrine obtained following treatment with roxatidine acetate 75 mg or placebo twice a day for 7 days showed similar characteristics with no difference in the areas under the plasma concentration-time curves. In addition, roxatidine acetate 75 mg daily did not modify the clearance of propranolol, diazepam, desmethyldiazepam or controlled release theophylline preparations. Furthermore, there was no interference in the bioavailability of roxatidine acetate 150 mg daily when administered alone or in combination with a meal or antacids.

  4. Improvement of productivity in acetic acid fermentation with Clostridium thermoaceticum

    Energy Technology Data Exchange (ETDEWEB)

    Shah, M.M.; Cheryan, M. [Univ. of Illinois, Urbana, IL (United States)

    1995-12-31

    Production of acetic acid by a mutant strain of Clostridium thermoaceticum was compared in three types of membrane cell-recycle bioreactors. A modified fed-batch bioreactor (where the product is partially removed at the end of fermentation, but the cells are retained), and a two-stage CSTR (with product being removed continuously and the cells being recycled from the second to the first stage) resulted in better performance than a one-stage CSTR or batch fermenter. The difference in performance was greater at higher acetate concentration. With 45 g/L of glucose in the feed, productivity was 0.75-1.12 g/L-h and acetic acid concentrations were 34-38 g/L. This is more than double the batch system. The nutrient supply rate also appeared to have a strong influence on productivity of the microorganism.

  5. Crystal structure of febuxostat–acetic acid (1/1

    Directory of Open Access Journals (Sweden)

    Min Wu

    2015-05-01

    Full Text Available The asymmetric unit of the title compound [systematic name: 2-(3-cyano-4-isobutyloxyphenyl-4-methylthiazole-5-carboxylic acid–acetic acid (1/1], C16H16N2O3S·CH3COOH, contains a febuxostat molecule and an acetic acid molecule. In the febuxostat molecule, the thiazole ring is nearly coplanar with the benzene ring [dihedral angle = 3.24 (2°]. In the crystal, the febuxostat and acetic acid molecules are linked by O—H...O, O—H...N hydrogen bonds and weak C—H...O hydrogen bonds, forming supramolecular chains propagating along the b-axis direction. π–π stacking is observed between nearly parallel thiazole and benzene rings of adjacent molecules; the centroid-to-centroid distances are 3.8064 (17 and 3.9296 (17 Å.

  6. Syntrophic acetate oxidation in industrial CSTR biogas digesters.

    Science.gov (United States)

    Sun, Li; Müller, Bettina; Westerholm, Maria; Schnürer, Anna

    2014-02-10

    The extent of syntrophic acetate oxidation (SAO) and the levels of known SAO bacteria and acetate- and hydrogen-consuming methanogens were determined in sludge from 13 commercial biogas production plants. Results from these measurements were statistically related to the prevailing operating conditions, through partial least squares (PLS) analysis. This revealed that high abundance of microorganisms involved in SAO was positively correlated with relatively low abundance of aceticlastic methanogens and high concentrations of free ammonia (>160 mg/L) and volatile fatty acids (VFA). Temperature was identified as another influencing factor for the population structure of the syntrophic acetate oxidising bacteria (SAOB). Overall, there was a high abundance of SAOB in the different digesters despite differences in their operating parameters, indicating that SAOB are an enduring and important component of biogas-producing consortia.

  7. Characterization of differently sized granule fractions of yellow pea, cowpea and chickpea starches after modification with acetic anhydride and vinyl acetate

    NARCIS (Netherlands)

    Huang, J.; Schols, H.A.; Jin, Z.; Sulmann, E.; Voragen, A.G.J.

    2007-01-01

    The effect of reagent type on the properties of acetylated starches was studied for yellow pea, cowpea and chickpea starches after modification with acetic anhydride and vinyl acetate. Samples modified with vinyl acetate showed higher swelling volume and peak viscosity than those acetylated with ace

  8. Search for Deuterated methyl acetate in the ISM

    Science.gov (United States)

    Gorai, Prasanta; Chakrabarti, Sandip Kumar; Das, Ankan; Majumdar, Liton; Sahu, Dipen; Sivaraman, Bhalamurugan

    2016-07-01

    Methyl acetate (CH_3COOCH_3 ) has been recently observed by IRAM 30 m radio telescope in Orion. But the existence of its deuterated form are yet to be confirmed. Here, we study the properties of methyl acetate and its singly deuterated forms (CH_3COOCH_3, CH_2DCOOCH_3 and CH_3COOCH_2D). Our simulation results reveal that deuterated forms of methyl acetate could efficiently be produced both in gas as well as in ice phase. Production of methyl acetate could follow radical-radical reaction between acetyl (CH_3CO) and methoxy (CH_3O) radicals. To predict abundances of CH_3COOCH_3 along with its two singly deuterated isotopomers and its two isomers (ethyl formate and hydroxy acetone), we prepare a large gas-grain chemical network to study chemical evolution of these molecules. Since gas phase rate coefficients of our newly adopted network for methyl acetate and its related species were unknown, in our simulation, either we consider similar rate coefficients for similar types of reactions (by following existing data bases) or we carry out quantum chemical calculations to estimate the unknown rate coefficients. For the surface reactions, we use adsorption energies of reactants from some earlier studies. Moreover, we perform quantum chemical calculations to find out various spectral properties of various forms of methyl acetate in infrared, ultraviolet and sub-millimeter regions. We prepare two catalog files for the rotational transitions of CH_2DCOOCH_3 and CH_3COOCH_2D in JPL format, which might be useful for its detection in regions of interstellar media where CH_3COOCH_3 has already been observed.

  9. Rotational study of the bimolecule acetic acid-fluoroacetic acid

    Science.gov (United States)

    Feng, Gang; Gou, Qian; Evangelisti, Luca; Caminati, Walther

    2017-01-01

    The rotational spectrum of the acetic acid-fluoroacetic acid bimolecule was measured by using a pulsed jet Fourier transform microwave spectrometer. One conformer, in which fluoroacetic acid is in trans form, has been observed. The rotational transitions are split into two component lines, due to the internal rotation of the methyl group of acetic acid. From these splittings, the corresponding V3 barrier has been determined. The dissociation energy of this complex has been estimated to 66 kJ/mol. An increase of the distance between the two monomers upon the OH → OD substitution (Ubbelohde effect) has been observed.

  10. Acetylation of cellulose nanowhiskers with vinyl acetate under moderate conditions.

    Science.gov (United States)

    Cetin, Nihat Sami; Tingaut, Philippe; Ozmen, Nilgül; Henry, Nathan; Harper, David; Dadmun, Mark; Sèbe, Gilles

    2009-10-08

    A novel and straightforward method for the surface acetylation of cellulose nanowhiskers by transesterification of vinyl acetate is proposed. The reaction of vinyl acetate with the hydroxyl groups of cellulose nanowhiskers obtained from cotton linters was examined with potassium carbonate as catalyst. Results indicate that during the first stage of the reaction, only the surface of the nanowhiskers was modified, while their dimensions and crystallinity remained unchanged. With increasing reaction time, diffusion mechanisms controlled the rate, leading to nanowhiskers with higher levels of acetylation, smaller dimensions, and lower crystallinity. In THF, a solvent of low polarity, the suspensions from modified nanowhiskers showed improved stability with increased acetylation.

  11. MORPHOLOGY, IN VITRO - DEGRADATION AND DRUG RELEASE PROFILE OF POLY (ETHYLENE-CO-VINYL ACETATE / MICROCRYSTALLINE CELLULOSE ACETATE

    Directory of Open Access Journals (Sweden)

    K. Lakshmi Narayana

    2011-06-01

    Full Text Available Microcrystalline cellulose acetate (MCC was incorporated in poly (ethylene-co-vinyl acetate (EVA at different loading. The morphology, swelling properties and drug release profile were studied with respect to MCC loading to study its potential application as ocular inserts. The XRD patterns showed a good compatibility between the components. However swelling ratio and in-vitro degradation of EVA increase with MCC loading. This has been explained in terms of the hygroscopic nature of cellulose acetate. The study shows that EVA/MCC system can be tuned in terms of important parameters such as swelling behavior, in vitro release and degradation by varying blend composition, thus fulfilling specific biomedical requirements.

  12. Fate and residues of trenbolone acetate in edible tissues from sheep amd calves implanted with tritium-labeled trenbolone acetate

    Energy Technology Data Exchange (ETDEWEB)

    Evrard, P.; Maghuin-Rogister, G.; Rico, A.G. (Univ. of Liege (Belgium))

    1989-06-01

    In order to study the fate and residues of trenbolone acetate in edible tissues, two groups of six animals from two ruminant species (ewes and calves) were implanted with (3H)trenbolone acetate. The distribution of extractable radioactive residues was measured in liver, kidney and muscle. We found that the largest proportion of residues was not extractable and thus was considered as covalently bound residues. The proportion of the main extractable metabolites (17 alpha-trenbolone, trendione, 17 beta-trenbolone) was measured. The evaluation of the distribution of trenbolone acetate metabolites directly soluble in water showed that unknown metabolite(s) were predominant. The covalent binding to nucleic acids was measured. It was so low that it was not detectable. The results are discussed in light of the data presented in the scientific report on anabolic agents in animal production from the European scientific working group.

  13. Experimental Measurements and Correlations Isobaric Vapor-Liquid Equilibria for Water + Acetic Acid + Sec-butyl Acetate at 101.3 kPa

    Institute of Scientific and Technical Information of China (English)

    LI Ling; HE Yong; WU Yanxiang; ZOU Wenhu

    2013-01-01

    Isobaric vapor-liquid equilibrium(VLE) data for acetic acid + sec-butyl acetate and water + acetic acid + sec-butyl acetate systems were determined at 101.3 kPa using a modified Rose type.The nonideality of the vapor phase caused by the association of the acetic acid was corrected by the chemical theory and Hayden-O'Connell method.Thermodynamic consistency was tested for the binary VLE data.The experimental data were correlated successfully with the Non-Random Two Liquids (NRTL) model.The Root Mean Square Deviation (RMSD) of the ternary system was 0.0038.The saturation vapor pressure of sec-butyl acetate at 329 to 385 K was measured by means of two connected equilibrium cells.The vapor pressures of water and sec-butyl acetate were correlated with the Antoine equation.The binary interaction parameters and the ternary VLE data were obtained from this work.

  14. Thiosulphate conversion in a methane and acetate fed membrane bioreactor

    NARCIS (Netherlands)

    Suarez Zuluaga, D.A.; Timmers, P.H.A.; Plugge, C.M.; Stams, A.J.M.; Buisman, C.J.N.; Weijma, J.

    2016-01-01

    The use of methane and acetate as electron donors for biological reduction of thiosulphate in a 5-L laboratory membrane bioreactor was studied and compared to disproportionation of thiosulphate as competing biological reaction. The reactor was operated for 454 days in semi-batch mode; 30 % of its li

  15. The Use of Megestrol Acetate in Some Feline Dermatological Problems

    OpenAIRE

    Gosselin, Y.; Chalifoux, A.; Papageorges, M.

    1981-01-01

    Twenty-one cats were treated with megestrol acetate because they were showing clinical signs associated with one of the following problems: eosinophilic ulcer, eosinophilic plaque, neurodermatitis, endocrine alopecia and miliary dermatitis. The dosage schedule was 5 mg orally per day per cat for seven days, then 5 mg every three days for 21 days.

  16. Demixing and gelation behavior of ternary cellulose acetate solutions

    NARCIS (Netherlands)

    Reuvers, A.J.; Altena, F.W.; Smolders, C.A.

    1986-01-01

    The demixing behavior on cooling of ternary systems of cellulose acetate/solvent/water has been examined for CA concentrations up to 40 wt% CA in several solvents. Cloud points have been measured as a function of cooling rate. The rapid process of liquid - liquid demixing can be discriminated from t

  17. Acetate stimulates secretion in the rabbit mandibular gland

    DEFF Research Database (Denmark)

    Novak, I; Young, J A

    1989-01-01

    In isolated perfused rabbit mandibular glands undergoing stimulation with 0.8 microM acetylcholine, replacement of HCO3- with acetate (25 mM) increased fluid secretion by more than 100%. Other short-chain fatty acids, except for propionate, had a similar effect. We focused our further studies...

  18. Photocatalytic decomposition of cortisone acetate in aqueous solution

    NARCIS (Netherlands)

    Sobral Romao, Joana; Hamdy, Mohamed S.; Mul, Guido; Baltrusaitis, Jonas

    2015-01-01

    The photocatalytic decomposition of cortisone 21-acetate (CA), a model compound for the commonly used steroid, cortisone, was studied. CA was photocatalytically decomposed in a slurry reactor with the initial rates between 0.11 and 0.46 mg L−1 min−1 at 10 mg L−1 concentration, using the following he

  19. Intramolecular carbon isotope distribution of acetic acid in vinegar.

    Science.gov (United States)

    Hattori, Ryota; Yamada, Keita; Kikuchi, Makiko; Hirano, Satoshi; Yoshida, Naohiro

    2011-09-14

    Compound-specific carbon isotope analysis of acetic acid is useful for origin discrimination and quality control of vinegar. Intramolecular carbon isotope distributions, which are each carbon isotope ratios of the methyl and carboxyl carbons in the acetic acid molecule, may be required to obtain more detailed information to discriminate such origin. In this study, improved gas chromatography-pyrolysis-gas chromatography-combustion-isotope ratio mass spectrometry (GC-Py-GC-C-IRMS) combined with headspace solid-phase microextraction (HS-SPME) was used to measure the intramolecular carbon isotope distributions of acetic acid in 14 Japanese vinegars. The results demonstrated that the methyl carbons of acetic acid molecules in vinegars produced from plants were mostly isotopically depleted in (13)C relative to the carboxyl carbon. Moreover, isotopic differences (δ(13)C(carboxyl) - δ(13)C(methyl)) had a wide range from -0.3 to 18.2‰, and these values differed among botanical origins, C3, C4, and CAM plants.

  20. First Acetic Acid Survey with CARMA in Hot Molecular Cores

    CERN Document Server

    Shiao, Y -S Jerry; Remijan, Anthony J; Snyder, Lewis E; Friedel, Douglas N

    2010-01-01

    Acetic acid (CH$_3$COOH) has been detected mainly in hot molecular cores where the distribution between oxygen (O) and nitrogen (N) containing molecular species is co-spatial within the telescope beam. Previous work has presumed that similar cores with co-spatial O and N species may be an indicator for detecting acetic acid. However, does this presumption hold as higher spatial resolution observations become available of large O and N-containing molecules? As the number of detected acetic acid sources is still low, more observations are needed to support this postulate. In this paper, we report the first acetic acid survey conducted with the Combined Array for Research in Millimeter-wave Astronomy (CARMA) at 3 mm wavelengths towards G19.61-0.23, G29.96-0.02 and IRAS 16293-2422. We have successfully detected CH$_3$COOH via two transitions toward G19.61-0.23 and tentatively confirmed the detection toward IRAS 16293-2422 A. The determined column density of CH$_3$COOH is 2.0(1.0)$\\times 10^{16}$ cm$^{-2}$ and the...

  1. 21 CFR 522.960b - Flumethasone acetate injection.

    Science.gov (United States)

    2010-04-01

    ... alcohol (as preservative); 8 milligrams of sodium chloride; 1 milligram of polysorbate 80; 0.1 milligram... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Flumethasone acetate injection. 522.960b Section 522.960b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN...

  2. Thermophilic anaerobic acetate-utilizing methanogens and their metabolism

    DEFF Research Database (Denmark)

    Mladenovska, Zuzana

    Methanosarcina strains required vitamins as growth factor. The isolates differed in cardinal growth pH and temperatures, the kinetic parameters - maximum specific growth rate and half saturation constant - and threshold values during growth on acetate. Analysis of total cell proteins by SDS-page gel...

  3. Preparation and properties of polyvinyl acetal sponge modified by chitosan

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The polyvinyl acetal sponge modified by chitosan was prepared by adding chitosan/polyvinyl alcohol (PVA) solution during the acetalation reaction of PVA and formaldehyde.The effect of vesicant and chitosan to the pore morphology,water absorption ratio,water absorption rate,expansion time and mechanical properties were studied.The polyvinyl acetal sponge modified by chitosan was used as a hemostatic packing material for the injured rabbit nasal tissue.The hemostatic effect and the healing effect of the modified sponge on the nasal mucosa after nasal surgery were studied.The results indicated that the polyvinyl acetal sponge modified by chitosan has an interconnected pore structure and the wall between large pores also has small pores.The chitosan adhered on the inner surface of the pores.The increased content of vesicant led to an increase in pore diameter,in the water absorption ratio and in expansion time.However,there was only a small change in the water absorption rate and a decrease in tensile strength and compression strength were noted.With an increase in chitosan content,the pore diameter and interconnection of the sponge was reduced.Water absorption ratio,expansion time and water absorption rate decreased,but tensile strength and compression strength improved.Observation of the rabbit nasal tissue after surgical operation suggested that polyvinyl acetal sponge modified by chitosan has an anti-inflammatory,hemostatic and antiadherent characteristic and could promote the healing and functional recovery of rabbit nasal mucosa.

  4. Megestrol acetate in the treatment of metastatic breast cancer

    NARCIS (Netherlands)

    J. Alexieva-Figusch (Jana)

    1984-01-01

    textabstractThere are many non-elucidated questions concerning cancer, especially of the breast, in which hormones are involved. The scope of this particular study is to bring more clarity on the role of the progestin megestrol acetate in the hormonal treatment of breast cancer. It should be kept in

  5. 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...

  6. Occurrence and metabolism of 7-hydroxy-2-indolinone-3-acetic acid in Zea mays

    Science.gov (United States)

    Lewer, P.; Bandurski, R. S.

    1987-01-01

    7-Hydroxy-2-indolinone-3-acetic acid was identified as a catabolite of indole-3-acetic acid in germinating kernels of Zea mays and found to be present in amounts of ca 3.1 nmol/kernel. 7-Hydroxy-2-indolinone-3-acetic acid was shown to be a biosynthetic intermediate between 2-indolinone-3-acetic acid and 7-hydroxy-2-indolinone-3-acetic acid-7'-O-glucoside in both kernels and roots of Zea mays. Further metabolism of 7-hydroxy-2-[5-3H]-indolinone-3-acetic acid-7'-O-glucoside occurred to yield tritiated water plus, as yet, uncharacterized products.

  7. The key to acetate: metabolic fluxes of acetic acid bacteria under cocoa pulp fermentation-simulating conditions.

    Science.gov (United States)

    Adler, Philipp; Frey, Lasse Jannis; Berger, Antje; Bolten, Christoph Josef; Hansen, Carl Erik; Wittmann, Christoph

    2014-08-01

    Acetic acid bacteria (AAB) play an important role during cocoa fermentation, as their main product, acetate, is a major driver for the development of the desired cocoa flavors. Here, we investigated the specialized metabolism of these bacteria under cocoa pulp fermentation-simulating conditions. A carefully designed combination of parallel 13C isotope labeling experiments allowed the elucidation of intracellular fluxes in the complex environment of cocoa pulp, when lactate and ethanol were included as primary substrates among undefined ingredients. We demonstrate that AAB exhibit a functionally separated metabolism during coconsumption of two-carbon and three-carbon substrates. Acetate is almost exclusively derived from ethanol, while lactate serves for the formation of acetoin and biomass building blocks. Although this is suboptimal for cellular energetics, this allows maximized growth and conversion rates. The functional separation results from a lack of phosphoenolpyruvate carboxykinase and malic enzymes, typically present in bacteria to interconnect metabolism. In fact, gluconeogenesis is driven by pyruvate phosphate dikinase. Consequently, a balanced ratio of lactate and ethanol is important for the optimum performance of AAB. As lactate and ethanol are individually supplied by lactic acid bacteria and yeasts during the initial phase of cocoa fermentation, respectively, this underlines the importance of a well-balanced microbial consortium for a successful fermentation process. Indeed, AAB performed the best and produced the largest amounts of acetate in mixed culture experiments when lactic acid bacteria and yeasts were both present.

  8. Dynamic changes of carbon isotope apparent fractionation factor to describe transition to syntrophic acetate oxidation during cellulose and acetate methanization.

    Science.gov (United States)

    Vavilin, Vasily A; Rytov, Sergey V

    2017-05-01

    To identify predominant metabolic pathway for cellulose methanization new equations that take into account dynamics of 13C are added to the basic model of cellulose methanization. The correct stoichiometry of hydrolysis, acidogenesis, acetogenesis and methanogenesis steps including biomass is considered. Using experimental data by Laukenmann et al. [Identification of methanogenic pathway in anaerobic digesters using stable carbon isotopes. Eng. Life Sci. 2010;10:1-6], who reported about the importance of ace`tate oxidation during mesophilic cellulose methanization, the model confirmed that, at high biomass concentration of acetate oxidizers, the carbon isotope fractionation factor amounts to about 1.085. The same model, suggested firstly for cellulose degradation, was used to describe, secondly, changes in, and in methane and carbon dioxide during mesophylic acetate methanization measured by Grossin-Debattista [Fractionnements isotopiques (13C/12C) engendres par la methanogenese: apports pour la comprehension des processus de biodegradation lors de la digestion anaerobie [doctoral thesis]. 2011. Bordeaux: Universite Bordeaux-1;2011. Available from: http://ori-oai.u-bordeaux1.fr/pdf/2011/GROSSIN-DEBATTISTA_JULIEN_2011.pdf . French].The model showed that under various ammonium concentrations, at dominating acetoclastic methanogenesis, the value decreases over time to a low level (1.016), while at dominating syntrophic acetate oxidation, coupled with hydrogenotrophic methanogenesis, slightly increases, reaching 1.060 at the end of incubation.

  9. Water requirements of the rayon- and acetate-fiber industry

    Science.gov (United States)

    Mussey, Orville Durey

    1957-01-01

    Water is required for several purposes in the manufacture of rayon and acetate fiber. These water requirements, as indicated by a survey of the water used by the plants operating in 1953, are both quantitative and qualitative. About 300 mgd (million gallons per day) of water was used in 1953 in the preparation of purified wood cellulose and cotton linters, the basic material from which the rayon and acetate fiber is made. An additional 620 mgd was used in the process of converting the cellulose to rayon and acetate fiber. The total, 920 mgd, is about 1 percent of the total estimated withdrawals of industrial water in the United States in 1953. The rayon- and acetate-fiber plants are scattered through eastern United States and generally are located in small towns or rural areas where there are abundant supplies of clean, soft water. Water use at a typical rayon-fiber plant was about 9 mgd, and at a typical acetate-fiber plant about 38 mgd. About 110 gallons of water was used to produce a pound of rayon fiber, 32 gallons per pound was process water and the remainder was used largely for cooling in connection with power production and air conditioning. For the manufacture of a pound of acetate fiber about 170 gallons of water was used. However, the field survey on which this report is based indicated a wide range in the amount of water used per pound of product. For example, in the manufacture of viscose rayon, the maximum unit water use was 8 times the minimum unit water use. Water use in summer was about 22 percent greater than average annual use. About 8 mgd Of water was consumed by evaporation in the manufacture of rayon and acetate fiber. More than 90 percent of the water used by the rayon and acetate industry was with- drawn from surface-water sources, about 8 percent from ground water, and less than 2 percent from municipal water supplies. All available analyses of the untreated waters used by the rayon and acetate industry were collected and studied. The

  10. Acetic Acid Production by an Electrodialysis Fermentation Method with a Computerized Control System

    OpenAIRE

    Nomura, Yoshiyuki; Iwahara, Masayoshi; Hongo, Motoyoshi

    1988-01-01

    In acetic acid fermentation by Acetobacter aceti, the acetic acid produced inhibits the production of acetic acid by this microorganism. To alleviate this inhibitory effect, we developed an electrodialysis fermentation method such that acetic acid is continuously removed from the broth. The fermentation unit has a computerized system for the control of the pH and the concentration of ethanol in the fermentation broth. The electrodialysis fermentation system resulted in improved cell growth an...

  11. [Clinical evaluation of roxatidine acetate hydrochloride injection as preanesthetic medication].

    Science.gov (United States)

    Kawanishi, M; Enomoto, A; Shimada, Y; Kurokawa, Y

    1991-09-01

    The effects of single intravenous administration of roxatidine acetate hydrochloride 75 mg on the volume and pH of gastric juice were investigated in 43 patients undergoing elective surgery under general anesthesia. The drug was given 1 hour before anesthesia. The percentages of patients with gastric pH above 2.5 and gastric juice volume under 25 ml were 95.3% and 97.7% at the time of induction of anesthesia and at the time of extubation, respectively. As for overall assessment on gastric secretion, 93.0% was judged as very effective. In 2 cases, pricking sensations were observed at the time of injection, but these symptoms disappeared without any treatment within a few minutes. No other adverse reactions nor abnormal laboratory test findings were observed. In conclusion, roxatidine acetate hydrochloride administered intravenously 1 hour prior to anesthesia is thought to be useful to prevent acid aspiration pneumonitis.

  12. Stabilization of Candida rugosa lipase during transacetylation with vinyl acetate.

    Science.gov (United States)

    Majumder, Abir B; Gupta, Munishwar N

    2010-04-01

    An optimally prepared Candida rugosa lipase aggregate cross-linked with bovine serum albumin, was found to overcome acetaldehyde deactivation during transacetylation of a series of benzyl alcohols with vinyl acetate. The formulation, under the same reaction conditions, exhibited 4-30x enhancement in the reaction rate as compared to the celite immobilized lyophilized formulation and 25-133x enhancement as compared to the free lyophilized enzyme depending upon the alcohol chosen. The racemic 1-phenylethanol, taken as one of the alcohols, underwent a more efficient enantioselective transacetylation giving 80% enantiomeric excess of the product, (R)-1-phenylethyl acetate, at 38% conversion (E = 15) within 24h while the enzyme immobilized on celite gave 83% enantiomeric excess at 18% conversion (E = 13) during the same period of time.

  13. Synthesis and herbicidal activities of benzothiazole N,O-acetals.

    Science.gov (United States)

    Ji, Zhiqin; Zhou, Fengxing; Wei, Shaopeng

    2015-10-01

    A new series of N,O-acetals were prepared via a simple one-pot reaction by the condensation of 2-amino-methybenzothiazole with aldehydes and alcohols. The title compounds were obtained in moderate to good yields in the presence of acid catalyst. Bioassay results indicated that some synthesized compounds had good herbicidal activity against both dicotyledon and monocotyledon weeds. This investigation provided a new type of herbicidal lead compounds, as well as its facile preparation method.

  14. Development of high performance vinyl acetate monomer (VAM) catalysts

    OpenAIRE

    2009-01-01

    The focus of this study was to develop high performance catalysts for the synthesis of vinyl acetate monomer (VAM). By systematic variation of different preparation parameters a multitude of shell catalysts consisting of PdAu nanoparticles supported on a bentonite carrier was explored. In order to investigate the influence of these alterations on catalytic performance, a catalyst classification was accomplished in a high-throughput Temkin test unit by comparison with a highly efficient commer...

  15. Successful Pregnancy after Treatment with Ulipristal Acetate for Uterine Fibroids

    OpenAIRE

    Javier Monleón; Alicia Martínez-Varea; Daniela Galliano; Antonio Pellicer

    2014-01-01

    This case report presents a clinical pregnancy after ulipristal acetate (UA) to decrease uterine fibroid size. A 37-year-old patient, gravida 1, abortus 1, with uterine fibroids was treated with 5 mg of UA daily for 13 weeks starting eight months after a multiple laparotomic myomectomy. Fibroid shrinkage and restoration of the morphology of endometrial cavity were evaluated in order to allow a subsequent pregnancy. A decrease of the uterine fibroids and a normal morphology of the endometrial ...

  16. Effect of lead acetate toxicity on experimental male albino rat

    Institute of Scientific and Technical Information of China (English)

    Nabil M Ibrahim; Esam A Eweis; Hossam S El-Beltagi; Yasmin E Abdel-Mobdy

    2012-01-01

    Objective: To evaluate the effect of different doses of lead acetate (1/20, 1/40 and 1/60 of LD50) on body weight gain, blood picture, plasma protein profile and the function of liver, kidney and thyroid gland. Methods: Male albino rats were divided into four groups, the first group represented the health control animals, while the second, third and fourth groups were ingested orally with sub lethal doses of lead acetate (1/20, 1/40 and 1/60) of the oral LD50, respectively. One dose was ingested every two days during the experimental period (14 weeks) including the adaptation time. Blood was collected and used for all analysis. Results: The results showed that, the ingestion of Pb2+ induced significant stimulation in glutamic-pyruvic transaminase (ALT) and glutamic-oxalacetic transaminease (AST) activity. Also, total soluble protein and albumin contents of plasma were significantly decreased, while the content of globulin was changed by the Pb2+ treatments. The cholinesterase activity was inhibited, but the activities of alkaline and acid phosphates and lactate dehydrogenase were stimulated, while plasma glucose level was elevated as a result of lead acetate intoxication. In case of blood picture, Pb2+ ingestion reduced the contents of hemoglobin and RBCs count of intoxicated rat’s blood and the plasma levels of T3, T4 and blood WBCs count were decreased. Conclusions: It can be concluded that lead acetate has harmful effect on experimental male albino rats. Therefore, the present work advises people to prevent exposure to the lead compound to avoid injurious hazard risk.

  17. THERMAL BEHAVIOR OF THERMOTROPIC HYDROXYETHYL CELLULOSE ACETATE/POLYETHYLENE BLENDS

    Institute of Scientific and Technical Information of China (English)

    WANG Hailin; CHEN Jinming; HUANG Yong; SHEN Jiarui

    1997-01-01

    The thermal behavior of thermotropic hydroxyethyl cellulose acetate (HECA)/polyethylene (PE) blends has been studied by DSC. It is found that the blends of HECA and PE are immiscible but the crystallization of PE is affected by HECA chains in the blends with more than 50% HECA, which results in the subordinate crystallization of PE and the formation of imperfect structures in the PE crystals. The imperfection of PE crystals in the blends can be eliminated after annealing at 393K.

  18. Galangal pungent component, 1'-acetoxychavicol acetate, activates TRPA1.

    Science.gov (United States)

    Narukawa, Masataka; Koizumi, Kanako; Iwasaki, Yusaku; Kubota, Kikue; Watanabe, Tatsuo

    2010-01-01

    We investigated the activation of transient receptor potential cation channel (TRP) subfamily V, member 1 (TRPV1) and TRP subfamily A, member 1 (TRPA1) by 1'-acetoxychavicol acetate (ACA), the main pungent component in galangal. ACA did not activate TRPV1-expressing human embryonic kidney (HEK) cells, but strongly activated TRPA1-expressing HEK cells. ACA was more potent than allyl isothiocyanate, the typical TRPA1 agonist.

  19. Fries Rearrangement of Phenyl Acetate over Solid Acid Catalyst

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A silica-supported zirconium based solid acid (ZS) has been used as catalyst for the Fries rearrangement of phenyl acetate (PA). The catalyst showed a higher PA conversion activity and a much higher selectivity for o-hydroxyacetophenone (o-HAP) than for strongly acidic zeolite catalysts. The supported catalyst was characterized by XRD, IR, XPS, pyridine-TPD and the surface area measurements. The catalytic properties were influenced significantly by pretreatment temperature.

  20. Interconversion kinetic studies of betamethasone acetate polymorphs in water.

    Science.gov (United States)

    Ke, Xue; Ping, QiNeng; Liao, ZhengGen

    2006-10-01

    This study assessed the effect of polymers on the transformation of polymorphs of betamethasone acetate (BA) when suspended in water. The results showed that the polymers, in particular HPMC E5, retarded the transition of the forms Ialpha and Ibeta. However, the form Ialpha, as the metastable form, with the aid of HPMC E5, was preferred for BA suspension preparation through kinetic studies, while the form Ibeta was not suitable due to its instability in water.

  1. Fries Rearrangement of Phenyl Acetate over Solid Acid Catalyst

    Institute of Scientific and Technical Information of China (English)

    CanXiongGUO; YanLIU; 等

    2002-01-01

    A silica-supported zirconium based solid acid (ZS) has been used as catalyst for the Fries rearrangement of phenyl acetate (PA). The catalyst showed a higher PA conversion activity and a much higher selectivity for o-hydroxyacetophenone (o-HAP) than for strongly acidic zeolite catalysts. The supported catalyst was characterized by XRD,IR,XPS,pyridine-TPD and the surface area measurements. The catalytic properties were influenced significantly by pretreatment temperature.

  2. Microwave Irradiation Promoted Synthesis of Aryloxy Acetic Acids

    Institute of Scientific and Technical Information of China (English)

    LIN Min; ZHOU Jin-mei; XIA Hai-ping; YANG Rui-feng; LIN Chen

    2004-01-01

    Several aryloxy acetic acids were synthesized under microwave irradiation. The factors, which affect the reaction, were investigated and optimized. It was revealed that the best yields(92.7%-97.4%) were obtained when the molar ratio of the reactants was n(ArOH) : n(NaOH): n(ClCH2CO2H) =1: 2.5: 1.2 with microwave irradiation power of 640 W for 65-85 s.

  3. Acetate:succinate CoA-transferase in the hydrogenosomes of Trichomonas vaginalis: Identification and characterization

    NARCIS (Netherlands)

    K.W.A. Grinsven; S. Rosnowsky (Silke); S.W.H. van Weelden (Susanne); S. Pütz (Simone); M. van der Giezen (Mark); W. Martin (William); J.J. van Hellemond (Jaap); A.G.M. Tielens (Aloysius); K. Henze (Katrin)

    2008-01-01

    textabstractAcetate:succinate CoA-transferases (ASCT) are acetate-producing enzymes in hydrogenosomes, anaerobically functioning mitochondria and in the aerobically functioning mitochondria of trypanosomatids. Although acetate is produced in the hydrogenosomes of a number of anaerobic microbial euka

  4. 40 CFR 180.1258 - Acetic acid; exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Acetic acid; exemption from the... Exemptions From Tolerances § 180.1258 Acetic acid; exemption from the requirement of a tolerance. An... acetic acid when used as a preservative on post-harvest agricultural commodities intended for animal...

  5. Identification of dihydrogalangal acetate in galangal [Alpinia galangal (L.) Swartz] extracts.

    Science.gov (United States)

    Yang, Xiaogen; Rohr, Martin; Jordan, Jason

    2009-04-22

    Dihydrogalangal acetate has been discovered for the first time in galangal roots [Alpinia galangal (L.) Swartz]. The compound has a taste sensation similar to galangal acetatethe pungent principle of galangalbut it is more stable in food and beverage applications. Therefore, dihydrogalangal acetate provides many advantages as a flavor ingredient for alcohol enhancement and taste modification. Dihydrogalangal acetate is present in approximately 0.0005% of fresh roots and in about 0.004% of dried roots. (S)-Dihydrogalangal acetate is found as the main optical isomer in galangal roots (98%), while its minor (R)-isomer is less abundant (2%). Enantiomers of galangal acetate and dihydrogalangal acetate were separated and evaluated by sensory analysis. (R)-Galangal acetate has a very faint woody and sweet aroma, and (R)-dihydrogalangal acetate is almost odorless, while (S)-galangal acetate has strong and (S)-dihydrogalangal acetate has weak pungent and woody notes. Although the aroma characters of these optical isomers are different, taste sensations were found to have no significant differences among galangal acetate, dihydrogalangal acetate, and their optical isomers.

  6. A continuous acetic acid system for polyacrylamide gel electrophoresis of gliadins and other prolamines.

    Science.gov (United States)

    Clements, R L

    1988-02-01

    A polyacrylamide gel electrophoresis system buffered by acetic acid alone was developed for electrophoresis of prolamines. When applied to gliadin electrophoresis, the acetic acid system produces more bands than does a conventional aluminum lactate-lactic acid system (using 12% acrylamide gels). The acetic acid system is relatively simple, requiring a single buffer component that is universally available in high purity.

  7. 75 FR 52269 - Acetic Acid Ethenyl Ester, Polymer With Oxirane; Tolerance Exemption

    Science.gov (United States)

    2010-08-25

    ...-2010-0429; FRL-8841-2] Acetic Acid Ethenyl Ester, Polymer With Oxirane; Tolerance Exemption AGENCY... from the requirement of a tolerance for residues of acetic acid ethenyl ester, polymer with oxirane... permissible level for residues of acetic acid ethenyl ester, polymer with oxirane on food or feed...

  8. 40 CFR 721.8658 - Modified polymer of vinyl acetate and quaternary ammonium compound (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified polymer of vinyl acetate and... Significant New Uses for Specific Chemical Substances § 721.8658 Modified polymer of vinyl acetate and.... (1) The chemical substance identified generically as modified polymer of vinyl acetate and...

  9. 21 CFR 175.350 - Vinyl acetate/crotonic acid copolymer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Vinyl acetate/crotonic acid copolymer. 175.350... COATINGS Substances for Use as Components of Coatings § 175.350 Vinyl acetate/crotonic acid copolymer. A copolymer of vinyl acetate and crotonic acid may be safely used as a coating or as a component of a...

  10. Investigations on organolead compounds III. The reaction of organolead compounds with ketene. (Triphenylplumbyl)acetic anhydride

    NARCIS (Netherlands)

    Willemsens, L.C.; Kerk, G.J.M. van der

    1965-01-01

    The reaction of ketene with triphenyllead hydroxide in diethyl ether gave (triphenylplumbyl)acetic anhydride, (Ph3PbCH2CO)2O, the first anhydride-substituted organolead compound known. The reaction of ketene with triphenyllead acetate in absolute ethanol gave ethyl (triphenylplumbyl)acetate, Ph3PbCH

  11. EFFECT OF GOSSYPOL ACETIC ACID ON CHROMOSOME ABERRATIONS AND ANEUPLOIDIES IN OOCYTES AND ZYGOTES OF MICE

    Institute of Scientific and Technical Information of China (English)

    WANGRen-Li; ZHANGZhong-Shu

    1989-01-01

    It was reported that gossypol acetic acid could effectively inhibit th~ implantation in ratA. This finding indicated that gossypol acet/c acid might also be used as a female contraceptive. The Present study further investigated the genetic effect of gossypol acetic

  12. A Kinetic Study of the Emulsion Polymerization of Vinyl Acetate

    DEFF Research Database (Denmark)

    Friis, N.; Nyhagen, L.

    1973-01-01

    The emulsion polymerization of vinyl acetate was studied at 50°C. It was found that the rate of polymerization was proportional to the 0.5 power of the initiator concentration and the 0.25 power of the number of particles. The number of particles was proportional to the power 0.5 ± 0.05 of the em...... to that of vinyl chloride. The linearity of the conversion-versus-time curve is explained as being due partly to a decrease in the desorption rate of radicals from the polymer particles and partly to a decrease in the termination rate constant.......The emulsion polymerization of vinyl acetate was studied at 50°C. It was found that the rate of polymerization was proportional to the 0.5 power of the initiator concentration and the 0.25 power of the number of particles. The number of particles was proportional to the power 0.5 ± 0.......05 of the emulsifier concentration, but independent of the initiator concentration. The limiting viscosity number of the polymers produced was independent of the initiator concentration and number of polymer particles. It is suggested that the mechanism of vinyl acetate emulsion polymerization is similar...

  13. Roxatidine acetate in the long term maintenance of gastric ulcers.

    Science.gov (United States)

    Börsch, G

    1988-01-01

    A non-comparative multicentre study of 78 patients with healed gastric ulcers who had received roxatidine acetate was conducted to determine the ulcer recurrence rates during 6 months' maintenance therapy with roxatidine acetate 75 mg at night. Gastric ulcer relapses occurred in 35% of patients, representing a worst possible outcome estimate, with no significant differences between smokers and non-smokers although heavy smoking appeared to increase the rate of relapse. The incidence of epigastric pain did not significantly increase over the duration of therapy and while some patients complained of mild pain at the start of the trial all subjects had endoscopically confirmed healed ulcers. The consumption of antacids for symptom relief was low, reaching an average of 0.75 tablets a day which was insufficient to influence intragastric pH. Continuous poor appetite and pyrosis were reported by about 5% of subjects. Of 2 patients who complained of mild to moderate side effects, 1 discontinued treatment. In addition, there were no clinically significant changes in haematological and biochemical variables. Thus, maintenance therapy with roxatidine acetate 75 mg at night is safe and generally effective in preventing symptomatic relapse.

  14. Roxatidine acetate in the long term maintenance of duodenal ulcers.

    Science.gov (United States)

    Brunner, G

    1988-01-01

    A non-comparative multicentre study of 105 patients with healed duodenal ulcers was conducted to determine the effect on ulcer recurrence of 6 months' maintenance treatment with roxatidine acetate 75 mg daily. All patients had previously received roxatidine acetate treatment. 31 patients out of 89 had 32 relapsed ulcers after 6 months of treatment, which represents an overall relapse rate of around 30%; the relapse rate in smokers was double that of non-smokers. The overall incidence of epigastric pain did not increase significantly over the period of the trial, although some patients complained of mild pain when they entered the study despite having endoscopically confirmed healed ulcers. At the end of the study continuous poor appetite and pyrosis were reported by 17% and 6% of patients, respectively. Side effects, which included constipation and diarrhoea, were reported by 4 patients, 1 of whom withdrew from therapy. There were no clinically significant changes in laboratory values. Thus, maintenance treatment with roxatidine acetate 75 mg daily proved a safe and effective method of preventing symptomatic duodenal ulcer relapse.

  15. Stimulation of hepatic glycogenolysis by phorbol-12-myristate-13-acetate

    Energy Technology Data Exchange (ETDEWEB)

    Patel, T.B.

    1986-05-01

    In isolated perfused rat livers, infusion of phorbol-12-myristate-13-acetate (150 nM) resulted in a three-fold stimulation of the rate of glucose production. This response was maximal at perfusate phorbol ester concentration of 150 nM, and was significantly diminished at higher concentrations of the phorbol ester (e.g. 300 nM). Stimulation of glycogenolysis by phorbol ester was greatly decreased in livers perfused infusion into livers perfused with calcium-free medium. Phorbol-12-myristate-13-acetate infusion into livers perfused in the absence of calcium did not result in calcium efflux from the livers. Additionally, in hepatocytes isolated from livers of fed rats neither the phorbol ester nor 1-oleoyl-2-acetyl-rac-glycerol, stimulated the rate of glucose production. This last result along with the observations that in isolated perfused rat livers, phorbol-12-myristate-13-acetate increases portal pressure, and decreases oxygen consumption suggests that stimulation of hepatic glycogenolysis by phorbol ester is the result of increased vasoconstriction, and is not a consequence of a direct effect of the phorbol ester on liver parenchymal cells.

  16. Observations on a laboratory method for submerged acetic fermentation.

    Science.gov (United States)

    LOPEZ, A; JOHNSON, L W; WOOD, C B

    1961-09-01

    Submerged acetic fermentation experiments were performed for the purpose of determining the conditions under which this type of fermentation should be conducted under laboratory conditions. The apparatus used consisted of a set of glass tubes provided with air spargers. Acetobacter acetigenum was found to be the most suitable bacterium among six Acetobacter compared under submerged acetic fermentation conditions in a synthetic medium. Statistically significant different rates of fermentation were observed in acetators that were identical in construction, fermentation medium, and aeration characteristics. Extremely long growth lag periods and complete absence of growth were often observed when starting fermentations. The causes of this behavior were investigated. It was found that it was not produced by lack of nutrients or by presence of a bacteriophage. Different kinds of bacterial starters were studied and compared. Cultures maintained in a liquid medium were reliable starters with a short growth lag period. Liquid medium cultures maintained their good starter characteristics after periods of storage of up to 11 weeks at 40 F (4 C).

  17. Controlled free radical polymerization of vinyl acetate with cobalt acetoacetonate

    Indian Academy of Sciences (India)

    Mohammad Ali Semsarzadeh; Sahar Amiri

    2012-03-01

    The polymerization of vinyl acetate with the complex catalyst of cobalt acetoacetonate [Co (acac)2] and DMF ligand with benzoyl peroxide initiator has been successfully carried out in bulk and in solution. The bulk polymerization has been used in a new route consisting of a one-step polymer formation in a fine capillary tube. In this process, the high rate of propagation was used to carry out the reaction in a microcapillary tube. Under 60°C, the colour-free reaction without solid catalyst impurity was 95% complete within a few hours. The high molecular weight of polyvinyl acetate (PVAc) with its relatively low molecular distribution without unreacted monomer provided a new method in microprocessing of the controlled radical polymerization of vinyl acetate in a one-step polymerization process. PVAc polymerization systems showed induction time, which was reduced in this reaction with using complex of DMF/ Co(acac)2. The kinetics of the reaction with a smaller degree of branching from this catalyst indicated that the electronegativity of the transition metal and diffusion of the homogeneous catalyst with DMF are important factors of fast polymerization in the bulk. Thermal properties of the polymer indicated a lower glass transition state. The easily reformed or stretched microsolid polymer demonstrated 20% crystallinity.

  18. Migration of 2-butoxyethyl acetate from polycarbonate infant feeding bottles

    DEFF Research Database (Denmark)

    Petersen, Jens Højslev; Lund, K.H.

    2003-01-01

    An enforcement campaign was carried out to assess the migration of 2-butoxyethyl acetate (2-BEA) from polycarbonate infant feeding bottles intended for repeated use. Migration was measured by three successive migration tests into two of the European Union official food simulants: distilled water......-BEA was found from eight of 12 bottles. However, migration above the target value of 0.33 mg kg(-1) was not observed in the third decisive test from any of the 12 different brands of polycarbonate feeding bottles. A migration of between 0.05 and 0.26 mg kg(-1) from seven of 12 bottles was measured...... to 3% acetic acid in the third test, whereas no migration to distilled water was observed in the third test. The average recovery of 2-BEA after the 10-day exposure at the target value of 0.33 mg kg(-1) was 77% into distilled water and 36% into 3% acetic acid. The limited recovery was understandable...

  19. Evaporation kinetics of acetic acid-water solutions

    Science.gov (United States)

    Duffey, K.; Wong, N.; Saykally, R.; Cohen, R. C.

    2012-12-01

    The transport of water molecules across vapor-liquid interfaces in the atmosphere is a crucial step in the formation and evolution of cloud droplets. Despite decades of study, the effects of solutes on the mechanism and rate of evaporation and condensation remain poorly characterized. The present work aims to determine the effect of atmospherically-relevant solutes on the evaporation rate of water. In our experiments, we create a train of micron-sized droplets and measure their temperature via Raman thermometry as they undergo evaporation without condensation. Analysis of the cooling rate yields the evaporation coefficient (γ). Previous work has shown that inorganic salts have little effect on γ, with surface-adsorbing anions causing a slight reduction in the coefficient from that measured for pure water. Organic acids are ubiquitous in aqueous aerosol and have been shown to disrupt the surface structure of water. Here we describe measurements of the evaporation rate of acetic acid solutions, showing that acetic acid reduces γ to a larger extent than inorganic ions, and that γ decreases with increasing acetic acid concentration.

  20. Kinetics of xylose dehydration into furfural in acetic acid

    Institute of Scientific and Technical Information of China (English)

    Zhou Chen; Weijiang Zhang; Jiao Xu; Pingli Li

    2015-01-01

    In this paper kinetics of xylose dehydration into furfural using acetic acid as catalyst was studied comprehensively and systematical y. The reaction order of both furfural and xylose dehydration was determined and the reaction activation energy was obtalned by nonlinear regression. The effect of acetic acid concentration was also investi-gated. Reaction rate constants were galned. Reaction rate constant of xylose dehydration is k1 ¼ 4:189 . 1010 ½A.0:1676 exp −108:6.1000RT . ., reaction rate constant of furfural degradation is k2 ¼ 1:271 . 104½A.0:1375 exp−63:413.1000RT . and reaction rate constant of condensation reaction is k3 ¼ 3:4051 . 1010½A.0:1676 exp−104:99.1000RT .. Based on this, the kinetics equation of xylose dehydration into furfural in acetic acid was set up according to theory of Dunlop and Furfural generating rate equation is dd½F.t ¼ k1½X.0e−k1t−k2½F.−k3½X.0e−k1t½F.. © 2015 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. Al rights reserved.

  1. Oxidation of acetate through reactions of the citric acid cycle by Geobacter sulfurreducens in pure culture and in syntrophic coculture

    OpenAIRE

    2000-01-01

    Geobacter sulfurreducens strain PCA oxidized acetate to CO2 via citric acid cycle reactions during growth with acetate plus fumarate in pure culture, and with acetate plus nitrate in coculture with Wolinella succinogenes. Acetate was activated by succinyl-CoA:acetate CoA-transferase and also via acetate kinase plus phosphotransacetylase. Citrate was formed by citrate synthase. Soluble isocitrate and malate dehydrogenases reduced NADP+ and NAD+, respectively. Oxidation of 2-oxoglutarate was me...

  2. Effect of wood acetylation with vinyl acetate and acetic anhydride on the properties of wood-plastic composites

    Directory of Open Access Journals (Sweden)

    Nilgül Özmen

    2013-02-01

    Full Text Available Chemical modifications of Scots pine (Pinus slyvestris wood flour were performed with vinyl acetate (VA and acetic anhydride (AA in the presence of potassium carbonate as a catalyst. Scots pine wood flour samples were successfully acetylated with VA (19 wt% gain and AA (24 wt% gain. The effect of chemical modification of the Scots pine wood flour with AA and VA on the mechanical properties of wood high-density polyethylene composites (WPC were determined. It was observed that acetylation of wood flour allowed a significant increase in both the mechanical properties and the thermal stability of the WPCs. It was concluded that acetylation of lignocellulosic fibers improves thermal stability, dispersion in the polymer matrix, and compatibility with the polymer matrix.

  3. Change in the plasmid copy number in acetic acid bacteria in response to growth phase and acetic acid concentration.

    Science.gov (United States)

    Akasaka, Naoki; Astuti, Wiwik; Ishii, Yuri; Hidese, Ryota; Sakoda, Hisao; Fujiwara, Shinsuke

    2015-06-01

    Plasmids pGE1 (2.5 kb), pGE2 (7.2 kb), and pGE3 (5.5 kb) were isolated from Gluconacetobacter europaeus KGMA0119, and sequence analyses revealed they harbored 3, 8, and 4 genes, respectively. Plasmid copy numbers (PCNs) were determined by real-time quantitative PCR at different stages of bacterial growth. When KGMA0119 was cultured in medium containing 0.4% ethanol and 0.5% acetic acid, PCN of pGE1 increased from 7 copies/genome in the logarithmic phase to a maximum of 12 copies/genome at the beginning of the stationary phase, before decreasing to 4 copies/genome in the late stationary phase. PCNs for pGE2 and pGE3 were maintained at 1-3 copies/genome during all phases of growth. Under a higher concentration of ethanol (3.2%) the PCN for pGE1 was slightly lower in all the growth stages, and those of pGE2 and pGE3 were unchanged. In the presence of 1.0% acetic acid, PCNs were higher for pGE1 (10 copies/genome) and pGE3 (6 copies/genome) during the logarithmic phase. Numbers for pGE2 did not change, indicating that pGE1 and pGE3 increase their PCNs in response to acetic acid. Plasmids pBE2 and pBE3 were constructed by ligating linearized pGE2 and pGE3 into pBR322. Both plasmids were replicable in Escherichia coli, Acetobacter pasteurianus and G. europaeus, highlighting their suitability as vectors for acetic acid bacteria.

  4. Acetate/acetyl-CoA metabolism associated with cancer fatty acid synthesis: overview and application.

    Science.gov (United States)

    Yoshii, Yukie; Furukawa, Takako; Saga, Tsuneo; Fujibayashi, Yasuhisa

    2015-01-28

    Understanding cancer-specific metabolism is important for identifying novel targets for cancer diagnosis and therapy. Induced acetate/acetyl CoA metabolism is a notable feature that is related to fatty acid synthesis supporting tumor growth. In this review, we focused on the recent findings related to cancer acetate/acetyl CoA metabolism. We also introduce [1-¹¹C]acetate positron emission tomography (PET), which is a useful tool to visualize up-regulation of acetate/acetyl CoA metabolism in cancer, and discuss the utility of [1-¹¹C]acetate PET in cancer diagnosis and its application to personalized medicine.

  5. Overexpression of acetyl-CoA synthetase in Saccharomyces cerevisiae increases acetic acid tolerance.

    Science.gov (United States)

    Ding, Jun; Holzwarth, Garrett; Penner, Michael H; Patton-Vogt, Jana; Bakalinsky, Alan T

    2015-01-01

    Acetic acid-mediated inhibition of the fermentation of lignocellulose-derived sugars impedes development of plant biomass as a source of renewable ethanol. In order to overcome this inhibition, the capacity of Saccharomyces cerevisiae to synthesize acetyl-CoA from acetic acid was increased by overexpressing ACS2 encoding acetyl-coenzyme A synthetase. Overexpression of ACS2 resulted in higher resistance to acetic acid as measured by an increased growth rate and shorter lag phase relative to a wild-type control strain, suggesting that Acs2-mediated consumption of acetic acid during fermentation contributes to acetic acid detoxification.

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

    Science.gov (United States)

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

    2015-01-01

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

  7. Influence of Alkylammonium Acetate Buffers on Protein-Ligand Noncovalent Interactions Using Native Mass Spectrometry

    Science.gov (United States)

    Zhuang, Xiaoyu; Gavriilidou, Agni F. M.; Zenobi, Renato

    2017-02-01

    We investigate the influence of three volatile alkylammonium acetate buffers on binding affinities for protein-ligand interactions determined by native electrospray ionization-mass spectrometry (ESI-MS). Four different types of proteins were chosen for this study. A charge-reduction effect was observed for all the cases studied, in comparison to the ions formed in ammonium acetate solution. When increasing the collision energy, the complexes of trypsin and the ligand were found to be more stable when sprayed from alkylammonium acetate buffers than from ammonium acetate. The determined dissociation constant (Kd) also exhibited a drop (up to 40%) when ammonium acetate was replaced by alkylammonium acetate buffers for the case of lysozyme and the ligand. The prospective uses of these ammonium acetate analogs in native ESI-MS are discussed in this paper as well.

  8. Acetic acid bacteria spoilage of bottled red wine -- a review.

    Science.gov (United States)

    Bartowsky, Eveline J; Henschke, Paul A

    2008-06-30

    Acetic acid bacteria (AAB) are ubiquitous organisms that are well adapted to sugar and ethanol rich environments. This family of Gram-positive bacteria are well known for their ability to produce acetic acid, the main constituent in vinegar. The oxidation of ethanol through acetaldehyde to acetic acid is well understood and characterised. AAB form part of the complex natural microbial flora of grapes and wine, however their presence is less desirable than the lactic acid bacteria and yeast. Even though AAB were described by Pasteur in the 1850s, wine associated AAB are still difficult to cultivate on artificial laboratory media and until more recently, their taxonomy has not been well characterised. Wine is at most risk of spoilage during production and the presence of these strictly aerobic bacteria in grape must and during wine maturation can be controlled by eliminating, or at least limiting oxygen, an essential growth factor. However, a new risk, spoilage of wine by AAB after packaging, has only recently been reported. As wine is not always sterile filtered prior to bottling, especially red wine, it often has a small resident bacterial population (bacteria. This spoilage is evident as a distinct deposit of bacterial biofilm in the neck of the bottle at the interface of the wine and the headspace of air, and is accompanied with vinegar, sherry, bruised apple, nutty, and solvent like off-aromas, depending on the degree of spoilage. This review focuses on the wine associated AAB species, the aroma and flavour changes in wine due to AAB metabolism, discusses the importance of oxygen ingress into the bottle and presents a hypothesis for the mechanism of spoilage of bottled red wine.

  9. Cytotoxic constituents of ethyl acetate fraction from Dianthus superbus.

    Science.gov (United States)

    Ding, Chengli; Zhang, Wu; Li, Jie; Lei, Jiachuan; Yu, Jianqing

    2013-01-01

    The ethyl acetate fraction (EE-DS) from Dianthus superbus was found to possess the cytotoxic activity against cancer cells in previous study. To investigate cytotoxic constituents, the bioassay-guided isolation of compounds from EE-DS was performed. Two dianthramides (1 and 2), three flavonoids (3-5), two coumarins (6 and 7) and three other compounds (8-10) were obtained. Structures of isolated compounds were identified by spectroscopic analysis. Cytotoxicity of the compounds against HepG2 cells was evaluated. Compound 1 showed the strongest cytotoxicity, compounds 10, 4, 3 and 5 had moderate cytotoxicity.

  10. Enthalpies of formation and lattice enthalpies of alkaline metal acetates

    Energy Technology Data Exchange (ETDEWEB)

    Aleixo, Ana I. [Departamento de Quimica e Bioquimica, Faculdade de Ciencias, Universidade de Lisboa, 1749-016 Lisbon (Portugal); Oliveira, Pedro H. [Centro de Quimica Estrutural, Complexo Interdisciplinar, Instituto Superior Tecnico, 1049-001 Lisbon (Portugal); Diogo, Herminio P. [Centro de Quimica Estrutural, Complexo Interdisciplinar, Instituto Superior Tecnico, 1049-001 Lisbon (Portugal); Minas da Piedade, Manuel E. [Departamento de Quimica e Bioquimica, Faculdade de Ciencias, Universidade de Lisboa, 1749-016 Lisbon (Portugal)]. E-mail: memp@fc.ul.pt

    2005-04-15

    The standard (p{sup o}=0.1MPa) molar enthalpies of formation in the crystalline state of the alkaline metal acetates CH{sub 3}COOM (M=Li, Na, K, Rb, Cs), at T=298.15K, were determined by reaction-solution calorimetry as: {delta}{sub f}H{sub m}{sup o}(CH{sub 3}COOLi,cr)=-(741.40+/-0.95)kJmol{sup -1}, {delta}{sub f}H{sub m}{sup o}(CH{sub 3}COONa,cr)=-(711.01+/-0.51)kJmol{sup -1}, {delta}{sub f}H{sub m}{sup o}(CH{sub 3}COOK,cr)=-(722.36+/-0.49)kJmol{sup -1}, {delta}{sub f}H{sub m}{sup o}(CH{sub 3}COORb,cr)=-(722.31+/-1.09)kJmol{sup -1}, {delta}{sub f}H{sub m}{sup o}(CH{sub 3}COOCs,cr)=-(726.10+/-1.07)kJmol{sup -1}. These results, taken together with the enthalpies of formation of the haloacetates XCH{sub 2}COOM (M=Li, Na; X=Cl, Br, I) and chloropropionates ClCH(CH{sub 3})COOM (M=Li, Na) re-evaluated from literature data were used to derive a consistent set of lattice energies, and discuss some general trends of the structure-energetics relationship for the CH{sub 3}COOM, XCH{sub 2}COOM, and ClCH(CH{sub 3})COOM compounds, based on the Kapustinskii approximation. It was found that the lattice energies of the haloacetates are essentially independent of the halogen and ca. 17-25kJmol{sup -1} smaller than those of the corresponding acetates. In addition, no significant difference between the lattice enthalpy values of the haloacetates and chloropropionates was observed. Finally, linear correlations of very similar slope were obtained by plotting the M-O bond distances derived from the Kapustinskii equation against the published experimental M-O bond distances for alkaline metal acetates and alkoxides. The analysis of these relations suggests that the metal-oxygen bond distances for the lithium, potassium, and rubidium acetates, whose molecular structures in the solid state have not been determined, can be estimated as 214, 288, and 304pm, respectively.

  11. Acetalization of Poly(vinyl alcohol) /Soybean Protein Fibers

    Institute of Scientific and Technical Information of China (English)

    YAN Dong-yan; FU Chang-fei; GU Li-xia

    2008-01-01

    Acetalizatioin on the blend fibers of poly(vinyl alcohol) (PVA) and soybean protein (SP) was studied by using dialdehydes as cross-linking agents. The optimal acetalization conditions were determined by Latin square experiment, where the modified fibers with good mechanical properties can be achieved by treating in 41 g/L dialdehyde solution at 67 ℃ for 9 min. The cross-linking reactions of PVA and SP with dialdehydes were confirmed by Fourier transform infrared (FTIR) spectroscopy. Tensile test and boiling water shrinkage measurements showed that the physical properties of PVA/SP fibers crosslinked by dialdehydes were improved comparing with those formalized fibers.

  12. DFT studies of CNT-functionalized uracil-acetate hybrids

    Science.gov (United States)

    Mirzaei, Mahmoud; Gulseren, Oguz

    2015-09-01

    Calculations based on density functional theory (DFT) have been performed to investigate the stabilities and properties of hybrid structures consisting of a molecular carbon nanotube (CNT) and uracil acetate (UA) counterparts. The investigated models have been relaxed to minimum energy structures and then various physical properties and nuclear magnetic resonance (NMR) properties have been evaluated. The results indicated the effects of functionalized CNT on the properties of hybrids through comparing the results of hybrids and individual structures. The oxygen atoms of uracil counterparts have been seen as the detection points of properties for the CNT-UA hybrids.

  13. Helenalin Acetate in in vitro Propagated Plants of Arnica montana.

    Science.gov (United States)

    Malarz, J; Stojakowska, A; Dohnal, B; Kisiel, W

    1993-02-01

    Propagated "IN VITRO" shoots and plantlets of ARNICA MONTANA L. (Asteraceae) have been shown to produce sesquiterpene lactones, i.e. helenalin and 11,13-dihydrohelenalin esters. The compounds were detected in green organs only; roots of the plantlets contained no sesquiterpene lactones. The helenalin acetate content in leaves of the plantlets (0.073% dry wt) was 4-times higher than in proliferated shoots (0.016% dry wt). The best rate of shoot multiplication was achieved on MS medium, supplemented with NAA 0.5mg/l and Kn 2.5 mg/l (formation of 22 shoots within 8 weeks).

  14. Improvement of acetic acid tolerance of Saccharomyces cerevisiae using a zinc-finger-based artificial transcription factor and identification of novel genes involved in acetic acid tolerance.

    Science.gov (United States)

    Ma, Cui; Wei, Xiaowen; Sun, Cuihuan; Zhang, Fei; Xu, Jianren; Zhao, Xinqing; Bai, Fengwu

    2015-03-01

    Acetic acid is present in cellulosic hydrolysate as a potent inhibitor, and the superior acetic acid tolerance of Saccharomyces cerevisiae ensures good cell viability and efficient ethanol production when cellulosic raw materials are used as substrates. In this study, a mutant strain of S. cerevisiae ATCC4126 (Sc4126-M01) with improved acetic acid tolerance was obtained through screening strains transformed with an artificial zinc finger protein transcription factor (ZFP-TF) library. Further analysis indicated that improved acetic acid tolerance was associated with improved catalase (CAT) activity. The ZFP coding sequence associated with the improved phenotype was identified, and real-time RT-PCR analysis revealed that three of the possible genes involved in the enhanced acetic acid tolerance regulated by this ZFP-TF, namely YFL040W, QDR3, and IKS1, showed decreased transcription levels in Sc4126-M01 in the presence of acetic acid, compared to those in the control strain. Sc4126-M01 mutants having QDR3 and IKS1 deletion (ΔQDR3 and ΔIKS1) exhibited higher acetic acid tolerance than the wild-type strain under acetic acid treatment. Glucose consumption rate and ethanol productivity in the presence of 5 g/L acetic acid were improved in the ΔQDR3 mutant compared to the wild-type strain. Our studies demonstrated that the synthetic ZFP-TF library can be used to improve acetic acid tolerance of S. cerevisiae and that the employment of an artificial transcription factor can facilitate the exploration of novel functional genes involved in stress tolerance of S. cerevisiae.

  15. Heterogeneous Reactions of Acetic Acid with Oxide Surfaces: Effects of Mineralogy and Relative Humidity.

    Science.gov (United States)

    Tang, Mingjin; Larish, Whitney A; Fang, Yuan; Gankanda, Aruni; Grassian, Vicki H

    2016-07-21

    We have investigated the heterogeneous uptake of gaseous acetic acid on different oxides including γ-Al2O3, SiO2, and CaO under a range of relative humidity conditions. Under dry conditions, the uptake of acetic acid leads to the formation of both acetate and molecularly adsorbed acetic acid on γ-Al2O3 and CaO and only molecularly adsorbed acetic acid on SiO2. More importantly, under the conditions of this study, dimers are the major form for molecularly adsorbed acetic acid on all three particle surfaces investigated, even at low acetic acid pressures under which monomers are the dominant species in the gas phase. We have also determined saturation surface coverages for acetic acid adsorption on these three oxides under dry conditions as well as Langmuir adsorption constants in some cases. Kinetic analysis shows that the reaction rate of acetic acid increases by a factor of 3-5 for γ-Al2O3 when relative humidity increases from 0% to 15%, whereas for SiO2 particles, acetic acid and water are found to compete for surface adsorption sites.

  16. Discovery of Methyl Acetate and Gauche Ethyl Formate in Orion

    CERN Document Server

    Tercero, B; Cernicharo, J; Nguyen, H V L; López, A; Caro, G M Muñoz

    2013-01-01

    We report on the discovery of methyl acetate, CH3COOCH3, through the detection of a large number of rotational lines from each one of the spin states of the molecule: AA species (A1 or A2), EA species (E1), AE species (E2), EE species (E3 or E4). We also report the detection, for the first time in space, of the $gauche$ conformer of ethyl formate, CH3CH2OCOH, in the same source. The trans conformer is also detected for the first time outside the galactic center source SgrB2. From the derived velocity of the emission of methyl acetate we conclude that it arises mainly from the compact ridge region with a total column density of (4.2+-0.5)E15 cm(-2). The derived rotational temperature is 150 K. The column density for each conformer of ethyl formate, trans and gauche, is (4.5+-1.0)E14 cm(-2). Their abundance ratio indicates a kinetic temperature of 135 K for the emitting gas and suggests that gas phase reactions could participate efficiently in the formation of both conformers in addition to cold ice mantle reac...

  17. [Clinical evaluation of roxatidine acetate hydrochlorides as a preanesthetic medication].

    Science.gov (United States)

    Namba, M; Chihara, E; Ibuki, T; Ashida, H; Fukushima, H; Tanaka, Y

    2001-02-01

    Roxatidine acetate hydrochloride capsule is slowly absorbed from the gastrointestinal tract, and its acid suppressive effect on the stomach is long-lasting compared with other H2-blockers. The reduction of gastric juice in perioperative period is considered advantageous for patients not only because it decreases the risk for aspiration pneumonia but also because it reduces the risk of bronchial spasm induced by gastroesophageal reflux of acidic gastric content. The effects of single oral administration of roxatidine acetate hydrochloride 150 mg at night before the operation on the volume and pH of gastric juice were investigated during anesthesia using two types of anesthetic agents (isoflurane and propofol) in 93 patients of three age groups (group Y: age 20-40, group M: age 41-64, group O: age 65 roxatidine on reduction of gastric juice was found at the time of anesthetic induction and 2 hours after the induction in any age group with either anesthetic agent. The serum concentration of roxatidine at the time of induction was much higher in group O. The value of residual concentration of roxatidine 20 hours after oral intake was estimated from the intraoperative measurements of serum concentration. The results suggest that single administration at night before the operation is sufficient for the oldest group, but an additive dose is recommended for the younger groups.

  18. Improving the photovoltaic performance of perovskite solar cells with acetate.

    Science.gov (United States)

    Zhao, Qian; Li, G R; Song, Jian; Zhao, Yulong; Qiang, Yinghuai; Gao, X P

    2016-12-09

    In an all-solid-state perovskite solar cell, methylammonium lead halide film is in charge of generating photo-excited electrons, thus its quality can directly influence the final photovoltaic performance of the solar cell. This paper accentuates a very simple chemical approach to improving the quality of a perovskite film with a suitable amount of acetic acid. With introduction of acetate ions, a homogeneous, continual and hole-free perovskite film comprised of high-crystallinity grains is obtained. UV-visible spectra, steady-state and time-resolved photoluminescence (PL) spectra reveal that the obtained perovskite film under the optimized conditions shows a higher light absorption, more efficient electron transport, and faster electron extraction to the adjoining electron transport layer. The features result in the optimized perovskite film can provide an improved short-circuit current. The corresponding solar cells with a planar configuration achieves an improved power conversion efficiency of 13.80%, and the highest power conversion efficiency in the photovoltaic measurements is up to 14.71%. The results not only provide a simple approach to optimizing perovskite films but also present a novel angle of view on fabricating high-performance perovskite solar cells.

  19. Scalar Relativistic Study of the Structure of Rhodium Acetate

    Directory of Open Access Journals (Sweden)

    Emily E. Edwards

    2004-01-01

    Full Text Available Abstract: Rhodium acetate, related rhodium carboxylates, and rhodium amide complexes are powerful catalysts for carbene chemistry. They readily promote the decomposition of diazo compounds and transfer the resulting carbene to a variety of substrates. There have been several quantum chemistry studies of these compounds, particularly of the acetate. These have all used non-relativistic methods, and all have shown optimized Rh-Rh bond lengths significantly longer than the experimental value. In this study we have surveyed several scalar relativistic DFT methods using Gaussian, Slater, and numerical basis functions (in DGAUSS, ADF, and DMOL3. Several combinations of exchange-correlation functionals with relativistic and non-relativistic effective core potentials (ECP were investigated, as were non-relativistic and all electron scalar relativistic methods. The combination of the PW91 exchange and PW91 correlation functional with the Christiansen-Ermler ECP gave the best results: 2.3918 Å compared to the experimental value of 2.3855±0.0005 Å.

  20. Modeling of sodium acetate recovery from aqueous solutions by electrodialysis.

    Science.gov (United States)

    Fidaleo, Marcello; Moresi, Mauro

    2005-09-05

    The main engineering parameters (i.e., ion transport numbers in solution and electro-membranes; effective solute and water transport numbers; effective membrane surface area, membrane surface resistances, and limiting current intensity) affecting the recovery of sodium acetate from model solutions by electrodialysis (ED) were determined in accordance with a sequential experimental procedure. Such parameters allowed a satisfactory simulation of a few validation tests carried out under constant or step-wisely variable current intensity. The performance of this ED process was characterized in terms of a current efficiency (omega) of about 93% in the constant-current region, a water transport number (t(W)) of about 15, and a specific energy consumption (epsilon) increasing from 0.14 to 0.31 kWh/kg for a solute recovery yield of 95% as the current density (j) was increased from 112 to 337 A/m2. The specific resistance of the anion- or cation-exchange membranes were found to be three or two times greater than those measured in aqueous NaCl solutions and are to be used to design and/or optimize ED stacks involved in the downstream processing of acetic acid fermentation broths.

  1. Unusal pattern of product inhibition: batch acetic acid fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Bar, R.; Gainer, J.L.; Kirwan, D.J.

    1987-04-20

    The limited tolerance of microorganisms to their metabolic products results in inhibited growth and product formation. The relationship between the specific growth rate, micro, and the concentration of an inhibitory product has been described by a number of mathematical models. In most cases, micro was found to be inversely proportional to the product concentration and invariably the rate of substrate utilization followed the same pattern. In this communication, the authors report a rather unusual case in which the formation rate of a product, acetic acid, increased with a decreasing growth rate of the microorganism, Acetobacter aceti. Apparently, a similar behavior was mentioned in a review report with respect to Clostridium thermocellum in a batch culture but was not published in the freely circulating literature. The fermentation of ethanol to acetic acid, C/sub 2/H/sub 5/OH + O/sub 2/ = CH/sub 3/COOH + H/sub 2/O is clearly one of the oldest known fermentations. Because of its association with the commercial production of vinegar it has been a subject of extensive but rather technically oriented studies. Suprisingly, the uncommon uncoupling between the inhibited microbial growth and the product formation appears to have been unnoticed. 13 references.

  2. Thiosulphate conversion in a methane and acetate fed membrane bioreactor.

    Science.gov (United States)

    Suarez-Zuluaga, Diego A; Timmers, Peer H A; Plugge, Caroline M; Stams, Alfons J M; Buisman, Cees J N; Weijma, Jan

    2016-02-01

    The use of methane and acetate as electron donors for biological reduction of thiosulphate in a 5-L laboratory membrane bioreactor was studied and compared to disproportionation of thiosulphate as competing biological reaction. The reactor was operated for 454 days in semi-batch mode; 30 % of its liquid phase was removed and periodically replenished (days 77, 119, 166, 258, 312 and 385). Although the reactor was operated under conditions favourable to promote thiosulphate reduction coupled to methane oxidation, thiosulphate disproportionation was the dominant microbial process. Pyrosequencing analysis showed that the most abundant microorganisms in the bioreactor were phototrophic green sulphur bacteria (GSB) belonging to the family Chlorobiaceae and thiosulphate-disproportionating bacteria belonging to the genus Desulfocapsa. Even though the reactor system was surrounded with opaque plastic capable of filtering most of the light, the GSB used it to oxidize the hydrogen sulphide produced from thiosulphate disproportionation to elemental sulphur. Interrupting methane and acetate supply did not have any effect on the microbial processes taking place. The ultimate goal of our research was to develop a process that could be applied for thiosulphate and sulphate removal and biogenic sulphide formation for metal precipitation. Even though the system achieved in this study did not accomplish the targeted conversion using methane as electron donor, it does perform microbial conversions which allow to directly obtain elemental sulphur from thiosulphate.

  3. Probiotic and Acetic Acid Effect on Broiler Chickens Performance

    Directory of Open Access Journals (Sweden)

    Martin Král

    2011-05-01

    Full Text Available Probiotics and organic acids are widely accepted as an alternative to in-feed antibiotics in poultry production. We carried the experiment with broiler chickens. In experiment we research effect of probiotic and acetic acids on the performance of broiler chickens. A total number of 200 one day old broiler chickens were distributed to two dietary groups. Broiler chickens in control group were fed with standard feed mixture and experimental group 1% vinegar contained 5% acetic acid used in drinking water and probiotics mixed with feed mixture. Body weight, FCR and GIT pH were recorded. The performance showed no statistically significant increase in body weight (P>0.05 in the weeks 1, 2, 3 and 4 of age. The body weight of broiler chickens was significant increase (P0.05 in weeks 5, and 6 of age. In different segments of the GIT was not statistically significant (P>0.05 difference of pH between the control and experimental groups.

  4. DISCOVERY OF METHYL ACETATE AND GAUCHE ETHYL FORMATE IN ORION

    Energy Technology Data Exchange (ETDEWEB)

    Tercero, B.; Cernicharo, J.; Lopez, A.; Caro, G. M. Munoz [Department of Astrophysics, CAB, INTA-CSIC, Crta Torrejon-Ajalvir, km. 4, E-28850 Torrejon de Ardoz, Madrid (Spain); Kleiner, I.; Nguyen, H. V. L., E-mail: terceromb@cab.inta-csic.es, E-mail: jcernicharo@cab.inta-csic.es, E-mail: lopezja@cab.inta-csic.es, E-mail: munozcg@cab.inta-csic.es, E-mail: isabelle.kleiner@lisa.u-pec.fr, E-mail: nguyen@pc.rwth-aachen.de [Laboratoire Interuniversitaire des Systemes Atmospheriques, CNRS/IPSL UMR7583 et Universites Paris Diderot et Paris Est, 61 av. General de Gaulle, F-94010 Creteil (France)

    2013-06-10

    We report on the discovery of methyl acetate, CH{sub 3}COOCH{sub 3}, through the detection of a large number of rotational lines from each one of the spin states of the molecule: AA species (A{sub 1} or A{sub 2}), EA species (E{sub 1}), AE species (E{sub 2}), and EE species (E{sub 3} or E{sub 4}). We also report, for the first time in space, the detection of the gauche conformer of ethyl formate, CH{sub 3}CH{sub 2}OCOH, in the same source. The trans conformer is also detected for the first time outside the Galactic center source SgrB2. From the derived velocity of the emission of methyl acetate, we conclude that it arises mainly from the compact ridge region with a total column density of (4.2 {+-} 0.5) Multiplication-Sign 10{sup 15} cm{sup -2}. The derived rotational temperature is 150 K. The column density for each conformer of ethyl formate, trans and gauche, is (4.5 {+-} 1.0) Multiplication-Sign 10{sup 14} cm{sup -2}. Their abundance ratio indicates a kinetic temperature of 135 K for the emitting gas and suggests that gas-phase reactions could participate efficiently in the formation of both conformers in addition to cold ice mantle reactions on the surface of dust grains.

  5. Olfactory attraction of Drosophila suzukii by symbiotic acetic acid bacteria

    KAUST Repository

    Mazzetto, Fabio

    2016-03-24

    Some species of acetic acid bacteria (AAB) play relevant roles in the metabolism and physiology of Drosophila spp. and in some cases convey benefits to their hosts. The pest Drosophila suzukii harbors a set of AAB similar to those of other Drosophila species. Here, we investigate the potential to exploit the ability of AAB to produce volatile substances that attract female D. suzukii. Using a two-way olfactometer bioassay, we investigate the preference of D. suzukii for strains of AAB, and using solid-phase microextraction gas chromatography–mass spectrometry we specifically characterize their volatile profiles to identify attractive and non-attractive components produced by strains from the genera Acetobacter, Gluconobacter, and Komagataeibacter. Flies had a preference for one strain of Komagataeibacter and two strains of Gluconobacter. Analyses of the volatile profiles from the preferred Gluconobacter isolates found that acetic acid is distinctively emitted even after 2 days of bacterial growth, confirming the relevance of this volatile in the profile of this isolate for attracting flies. Analyses of the volatile profile from the preferred Komagataeibacter isolate showed that a different volatile in its profile could be responsible for attracting D. suzukii. Moreover, variation in the concentration of butyric acid derivatives found in some strains may influence the preference of D. suzukii. Our results indicate that Gluconobacter and Komagataeibacter strains isolated from D. suzukii have the potential to provide substances that could be exploited to develop sustainable mass-trapping-based control approaches. © 2016 Springer-Verlag Berlin Heidelberg

  6. The effect of vinyl acetate in acetoclastic methanogenesis.

    Science.gov (United States)

    Durán, U; Gómez, J; Monroy, O; Ramírez, F

    2011-01-01

    The influence of vinyl acetate (VA) in the methanogenesis was evaluated, by using an upflow anaerobic sludge blanket reactor of 1.5L. The reactor was operated at 33.5 g/L volatile suspended solids to 30±2 °C, a hydraulic residence time of 1 day, an organic loading rate of 1 kgCOD/m3/d of two different mixtures of VA and glucose. The VA was methanized to 81% when its proportion was of 10% into reactor loading rate, when VA proportion increased to 25%, the methane production rate decreased to 62% and the acetate production rate increased almost 8 times. These results indicated that VA was only hydrolyzed and glucose was not used as a co-substrate. The effect of glucose on VA methanogenic degradation was evaluated through batch reactors of 60 mL, concluding that the glucose supported the methanogenesis without favoring the VA elimination. On the other hand, the results of the sludge from the reactor in the presence of VA demonstrated that VA caused an irreversibly inhibition of acetoclastic methanogenesis when the anaerobic sludge was exposed to this compound.

  7. The Kinetics of Cellulose Grafting with Vinyl Acetate Monomer

    Directory of Open Access Journals (Sweden)

    Éva Borbély

    2005-11-01

    Full Text Available Cellulose is a natural raw material recurring in a great quantity. The demand touse it more and more widely is increasing. The production of cellulose derivates started asearly as the 19th century, however the modification of these materials meant the breakingup the fibrous structure, which made their use more difficult in paper industry. Themodified cellulose made by graft copolymerization, however, keeps its fibrous character,which provides a great advantage regarding its use. Grafting of industrial cellulose pulpwith vinyl-acetate allows for the production of grafted wood cellulose fibres that have athermoplastic layer on their surface. The binder fibre (fibrid produced in this way can beexcellently used for producing synthetic papers.In the first part of my experiments I dealt with choosing the parameters of graftcopolymerization which are best suited to various uses and after that I studied thedependence of graft reaction on the composition and properties of industrial celluloseapplied. The selection of the suitable reaction parameters was followed by the study ofreaction speed and activation energy. I have stated that the gross reaction of graftingindustrial cellulose with vinyl-acetate monomer is a second order reaction, which is provenby the fact that the invert of the momentary monomer concentration of the system plottedagainst time is a linear function. The rise of the curves, that is, the reaction speed increaseswhen the temperature in the range of 293–323 K is increasing, while the average activationenergy decreases.

  8. Zinc acetate for the treatment of Wilson's disease.

    Science.gov (United States)

    Brewer, G J

    2001-09-01

    Zinc acetate (Galzin, Gate Pharmaceutical Co.) has been developed for the treatment of Wilson's disease, an inherited disease of copper accumulation and copper toxicity in brain and liver. Zinc acetate has been approved by the US FDA for maintenance therapy of adult and paediatric Wilson's disease patients but also has efficacy in the treatment of pregnant patients and presymptomatic patients from the beginning. It also has value as adjunctive therapy for the initial treatment of symptomatic patients. Zinc's mechanism of action involves induction of intestinal cell metallothionein (Mt), which blocks copper absorption from the intestinal track. A negative copper balance is caused by blockade not only of absorption of food copper but the blockade of reabsorption of the considerable amount of endogenously secreted copper in saliva, gastric juice and intestinal secretions. Zinc is completely effective in controlling copper levels and toxicity in Wilson's disease, as are other anticopper agents. Zinc's major advantage over other anticopper agents is its extremely low level of toxicity. The only side effect is some degree of initial gastric irritation in approximately10% of patients, which usually decreases and becomes insignificant over time. As with all long-term therapies, compliance is a problem in some patients and dictates regular monitoring with 24 h urine copper and zinc measurements. As with all anticopper therapies, over a long period of time, overtreatment and induction of copper deficiency can occur. This is to be avoided particularly in children because copper is required for growth.

  9. Improving the photovoltaic performance of perovskite solar cells with acetate

    Science.gov (United States)

    Zhao, Qian; Li, G. R.; Song, Jian; Zhao, Yulong; Qiang, Yinghuai; Gao, X. P.

    2016-12-01

    In an all-solid-state perovskite solar cell, methylammonium lead halide film is in charge of generating photo-excited electrons, thus its quality can directly influence the final photovoltaic performance of the solar cell. This paper accentuates a very simple chemical approach to improving the quality of a perovskite film with a suitable amount of acetic acid. With introduction of acetate ions, a homogeneous, continual and hole-free perovskite film comprised of high-crystallinity grains is obtained. UV-visible spectra, steady-state and time-resolved photoluminescence (PL) spectra reveal that the obtained perovskite film under the optimized conditions shows a higher light absorption, more efficient electron transport, and faster electron extraction to the adjoining electron transport layer. The features result in the optimized perovskite film can provide an improved short-circuit current. The corresponding solar cells with a planar configuration achieves an improved power conversion efficiency of 13.80%, and the highest power conversion efficiency in the photovoltaic measurements is up to 14.71%. The results not only provide a simple approach to optimizing perovskite films but also present a novel angle of view on fabricating high-performance perovskite solar cells.

  10. Solubilities of Isophthalic Acid in Acetic Acid + Water Solvent Mixtures

    Institute of Scientific and Technical Information of China (English)

    CHENG Youwei; HUO Lei; LI Xi

    2013-01-01

    The solubilities of isophthalic acid (1) in binary acetic acid (2) + water (3) solvent mixtures were determined in a pressurized vessel.The temperature range was from 373.2 to 473.2K and the range of the mole fraction of acetic acid in the solvent mixtures was from x2 =0 to 1.A new method to measure the solubility was developed,which solved the problem of sampling at high temperature.The experimental results indicated that within the temperature range studied,the solubilities of isophthalic acid in all mixtures showed an increasing trend with increasing temperature.The experimental solubilities were correlated by the Buchowski equation,and the calculate results showed good agreement with the experimental solubilities.Furthermore,the mixed solvent systems were found to exhibit a maximum solubility effect on the solubility,which may be attributed to the intermolecular association between the solute and the solvent mixture.The maximum solubility effect was well modeled by the modified Wilson equation.

  11. Catabolism of indole-3-acetic acid and 4- and 5-chloroindole-3-acetic acid in Bradyrhizobium japonicum

    DEFF Research Database (Denmark)

    Jensen, J B; Egsgaard, H; Van Onckelen, H

    1995-01-01

    chromatography and conventional mass spectrometry (MS) methods, including MS-mass spectroscopy, UV spectroscopy, and high-performance liquid chromatography-MS. The identified products indicate a novel metabolic pathway in which IAA is metabolized via dioxindole-3-acetic acid, dioxindole, isatin, and 2......-aminophenyl glyoxylic acid (isatinic acid) to anthranilic acid, which is further metabolized. Degradation of 4-Cl-IAA apparently stops at the 4-Cl-dioxindole step in contrast to 5-Cl-IAA which is metabolized to 5-Cl-anthranilic acid. Udgivelsesdato: 1995-Oct...

  12. Clostridium lentocellum SG6--a potential organism for fermentation of cellulose to acetic acid.

    Science.gov (United States)

    Ravinder, T; Swamy, M V; Seenayya, G; Reddy, G

    2001-12-01

    A cellulolytic, acetic acid producing anaerobic bacterial isolate, Gram negative, rod-shaped, motile, terminal oval shaped endospore forming bacterium identified as Clostridium lentocellum SG6 based on physiological and biochemical characteristics. It produced acetic acid as a major end product from cellulose fermentation at 37 degrees C and pH 7.2. Acetic acid production was 0.67 g/g cellulose substrate utilized in cellulose mineral salt (CMS) medium. Yeast extract (0.4%) was the best nitrogen source among the various nitrogenous nutrients tested in production medium containing 0.8% cellulose as substrate. No additional vitamins or trace elemental solution were required for acetic acid fermentation. This is the highest acetic acid fermentation yield in monoculture fermentation for direct conversion of cellulose to acetic acid.

  13. Synergistic effect of radiation on colon carcinogenesis induced by methylazoxymethanol acetate in ACI/N rats

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Takuji; Morishita, Yukio; Kawamori, Toshihiko; Suzui, Masumi; Kojima, Toshihiro; Sugie, Shigeyuki; Mori, Hideki (Gifu Univ. (Japan). Faculty of Medicine)

    1993-10-01

    The effect on colon and liver carcinogenicity in rats of a single X-irradiation exposure given either before or after methylazoxymethanol (MAM) acetate was studied in ACI/N rats of both sexes. A single dose of X-irradiation (3 Gy) was administered either 3 months before or after three weekly s.c. injection of MAM acetate (25 mg/kg body weight). At 365 days after the start, the incidence and multiplicity of MAM acetate-induced intestinal tumors were enhanced by X-irradiation either prior to or after the MAM acetate treatment. In addition, X-irradiation before MAM acetate increased the incidence of hepatocellular foci in either sex. In females, X-irradiation either before or after MAM acetate exposure decreased intestinal tumorigenesis. These findings suggest an apparent synergism of these agents in intestinal carcinogenesis of male rats. (author).

  14. Study on fluorescence spectra of molecular association of acetic acid-water

    Institute of Scientific and Technical Information of China (English)

    Caiqin Han; Ying Liu; Yang Yang; Xiaowu Ni; Jian Lu; Xiaosen Luo

    2009-01-01

    Fluorescence spectra of acetic acid-water solution excited by ultraviolet (UV) light are studied, and the relationship between fluorescence spectra and molecular association of acetic acid is discussed. The results indicate that when the exciting light wavelength is longer than 246 nm, there are two fluorescence peaks located at 305 and 334 nm, respectively. By measuring the excitation spectra, the optimal wavelengths of the two fluorescence peaks are obtained, which are 258 and 284 nm, respectively. Fluorescence spectra of acetic acid-water solution change with concentrations, which is primarily attributed to changes of molecular association of acetic acid in aqueous solution. Through theoretical analysis, three variations of molecular association have been obtained in acetic acid-water solution, which are the hydrated monomers, the linear dimers, and the water separated dimers. This research can provide references to studies of molecular association of acetic acid-water, especially studies of hydrogen bonds.

  15. A Study of the Catalysts for the Complete Oxidation of Low Concentration Ethyl Acetate and n-Butyl Acetate

    Institute of Scientific and Technical Information of China (English)

    DUAN; ZhiYing

    2001-01-01

    In this work, we have synthesized mixed oxides catalysts supported on γ-Al2O3,using some base metals such as La、 Sr、 Ce、 Ni、 Cu. At the space velocity of 56,000h-1 and at some range of concentration, the complete conversion temperatures( ≥ 98% )of Ethyl acetate and n-butyl acetate are 260℃ and 250℃ respectively. The work has an excellent prospect of industrial application.  I will introduce the experiment and results from the following tluee aspects. According to Figure 1, X-ray diffraction pattern of the catalyst have shown not only perovskite structure but also much independent CeO2 phase. During the preparation, the CeO2 was coated over support γ-A12O3 for the better Oxygen storage capacity .By co1mparison, we found that the activity of the catalyst with CeO2 was higher than the activity of the catalyst without CeO2.……

  16. A Study of the Catalysts for the Complete Oxidation of Low Concentration Ethyl Acetate and n-Butyl Acetate

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ In this work, we have synthesized mixed oxides catalysts supported on γ-Al2O3,using some base metals such as La、 Sr、 Ce、 Ni、 Cu. At the space velocity of 56,000h-1 and at some range of concentration, the complete conversion temperatures( ≥ 98% )of Ethyl acetate and n-butyl acetate are 260℃ and 250℃ respectively. The work has an excellent prospect of industrial application. I will introduce the experiment and results from the following tluee aspects. According to Figure 1, X-ray diffraction pattern of the catalyst have shown not only perovskite structure but also much independent CeO2 phase. During the preparation, the CeO2 was coated over support γ-A12O3 for the better Oxygen storage capacity .By co1mparison, we found that the activity of the catalyst with CeO2 was higher than the activity of the catalyst without CeO2.

  17. Use of pooled sodium acetate acetic acid formalin-preserved fecal specimens for the detection of intestinal parasites.

    Science.gov (United States)

    Gaafar, Maha R

    2011-01-01

    This study aimed at comparing detection of intestinal parasites from single unpreserved stool sample vs. sodium acetate acetic acid formalin (SAF)-preserved pooled samples, and stained with chlorazol black dye in routine practice. Unpreserved samples were collected from 120 patients and represented as Group I. Other three SAF-preserved samples were collected from the same patients over a 6-day period and represented as Groups IIa, IIb, and IIc. The latter groups were equally subdivided into two subgroups. The first subgroup of each of the three samples was examined individually, whereas the second subgroup of each were pooled and examined as a single specimen. All groups were examined by the routine diagnostic techniques; however, in group II when the diagnosis was uncertain, the chlorazol black dye staining procedure was carried out. Results demonstrated that out of 74 patients who continued the study, 12 cases (16%) were positive in group I, compared with 29 (39%) in the subgroups examined individually, and 27 (36%) in the pooled subgroups. Therefore, pooling of preserved fecal samples is an efficient and economical procedure for the detection of parasites. Furthermore, the chlorazol black dye was simple and effective in detecting the nuclear details of different parasites.

  18. Development of an Acetate-Fed or Sugar-Fed Microbial Power Generator for Military Bases

    Science.gov (United States)

    2011-01-01

    Sucrose • Acetate Propionate • Hydrogen gas • Lactate • Formate • !so-butyrate Unknown fbiomass -’-soluble products ) KM. 80 60 I" 20 DavO...lactate and acetate as fermentation products and is ready for test in the MFC modules. 1. Anode materials We compared the performances of acetate-fed...microbial electrolysis cells (MECs) with graphite rods and stainless steel meshes as anodes to select the optimum material for use in MFC modules to

  19. Overexpression of acetyl-CoA synthetase in Saccharomyces cerevisiae increases acetic acid tolerance

    OpenAIRE

    Ding, Jun; Holzwarth, Garrett; Penner, Michael H.; Patton-Vogt, Jana; Bakalinsky, Alan T.

    2015-01-01

    Acetic acid-mediated inhibition of the fermentation of lignocellulose-derived sugars impedes development of plant biomass as a source of renewable ethanol. In order to overcome this inhibition, the capacity of Saccharomyces cerevisiae to synthesize acetyl-CoA from acetic acid was increased by overexpressing ACS2 encoding acetyl-coenzyme A synthetase. Overexpression of ACS2 resulted in higher resistance to acetic acid as measured by an increased growth rate and shorter lag phase relative to a ...

  20. Excited-state proton transfer from pyranine to acetate in methanol

    Indian Academy of Sciences (India)

    Sudip Kumar Mondal; Subhadip Ghosh; Kalyanasis Sahu; Pratik Sen; Kankan Bhattacharyya

    2007-03-01

    Excited-state proton transfer (ESPT) of pyranine (8-hydroxypyrene-1,3,6-trisulphonate, HPTS) to acetate in methanol has been studied by steady-state and time-resolved fluorescence spectroscopy. The rate constant of direct proton transfer from pyranine to acetate (1) is calculated to be ∼ 1 × 109 M-1 s-1. This is slower by about two orders of magnitude than that in bulk water (8 × 1010 M-1 s-1) at 4 M acetate.

  1. RESEARCH ON THE INFLUENCE OF LEAD ACETATE ON THE GAMETOPHYTE OF SOME PTERIDOPHYTE SPECIES

    OpenAIRE

    Liliana Cristina SOARE; Codruţa-Mihaela DOBRESCU; Camelia Georgiana DIACONESCU

    2014-01-01

    The aim of this research was to study the influence of lead acetate on spore germination and gametophyte differentiation in the pteridophyte species Athyrium filix-femina, Dryopteris affinis and Dryopteris carthusiana. The study was conducted to determine the lead tolerance level of these species.The experimental variants were: Control - Knop solution, V1-100 ppm lead acetate and V2-500 ppm lead acetate. The spores were cultivated in 50 ml of experimental solutions. The culture vessels were k...

  2. P-chiral phosphine-sulfonate/palladium-catalyzed asymmetric copolymerization of vinyl acetate with carbon monoxide.

    Science.gov (United States)

    Nakamura, Akifumi; Kageyama, Takeharu; Goto, Hiroki; Carrow, Brad P; Ito, Shingo; Nozaki, Kyoko

    2012-08-01

    Utilization of palladium catalysts bearing a P-chiral phosphine-sulfonate ligand enabled asymmetric copolymerization of vinyl acetate with carbon monoxide. The obtained γ-polyketones have head-to-tail and isotactic polymer structures. The origin of the regio- and stereoregularities was elucidated by stoichiometric reactions of acylpalladium complexes with vinyl acetate. The present report for the first time demonstrates successful asymmetric coordination-insertion (co)polymerization of vinyl acetate.

  3. Validation of human physiologically based pharmacokinetic model for vinyl acetate against human nasal dosimetry data.

    Science.gov (United States)

    Hinderliter, P M; Thrall, K D; Corley, R A; Bloemen, L J; Bogdanffy, M S

    2005-05-01

    Vinyl acetate has been shown to induce nasal lesions in rodents in inhalation bioassays. A physiologically based pharmacokinetic (PBPK) model for vinyl acetate has been used in human risk assessment, but previous in vivo validation was conducted only in rats. Controlled human exposures to vinyl acetate were conducted to provide validation data for the application of the model in humans. Five volunteers were exposed to 1, 5, and 10 ppm 13C1,13C2 vinyl acetate via inhalation. A probe inserted into the nasopharyngeal region sampled both 13C1,13C2 vinyl acetate and the major metabolite 13C1,13C2 acetaldehyde during rest and light exercise. Nasopharyngeal air concentrations were analyzed in real time by ion trap mass spectrometry (MS/MS). Experimental concentrations of both vinyl acetate and acetaldehyde were then compared to predicted concentrations calculated from the previously published human model. Model predictions of vinyl acetate nasal extraction compared favorably with measured values of vinyl acetate, as did predictions of nasopharyngeal acetaldehyde when compared to measured acetaldehyde. The results showed that the current PBPK model structure and parameterization are appropriate for vinyl acetate. These analyses were conducted from 1 to 10 ppm vinyl acetate, a range relevant to workplace exposure standards but which would not be expected to saturate vinyl acetate metabolism. Risk assessment based on this model further concluded that 24 h per day exposures up to 1 ppm do not present concern regarding cancer or non-cancer toxicity. Validation of the vinyl acetate human PBPK model provides support for these conclusions.

  4. Polyphenolic acetates : A newer anti-Mycobacterial therapeutic option

    Directory of Open Access Journals (Sweden)

    Santram

    2014-01-01

    Full Text Available The objective of our research project was screening of various highly specific substrates of Acetoxy Drug: Protein Transacytylase (M.TAase for antimycobacterial activity. Mycobacterial culture was done in Middlebrook’s 7H9 media. Protein purification (Mycobacterial Tranacetylase, M.TAase was done by ion exchange chromatography and its demonstration was done on SDS- polyacrylamide gel electrophoresis (SDS-PAGE and western blot. Middlebrook’s 7H9 broth was procured from Becton Dickinson. CM-Sepharose, DEAE-Sepharose and Q-Sephharose were purchased from Amersham Pharmacia. Anti acetyl lysine polyclonal antibody was purchased from Cell Signaling. The Middlebrook 7H9 medium was used for M. smegmatis culture. The media was prepared according to the manufacturer’s instructions. The various Polyphenol acetate compounds were tested for their antimycobacterial activities. Minimal inhibitory concentrations (MIC were calculated by Alamar blue dye assay method. The GST protein was used as a receptor protein and purified Mycobacterial Glutamine Synthetase (GS as TAase for acetylation by DAMC. To demonstrate the TAase catalyzed acetylation of GST by DAMC, purified M.TAase (GS was preincubated with GST and DAMC followed by western blot using anti acetyl lysine antibody, which avidly react with the acetylated proteins. The growth pattern of M. smegmatis was diminished under the influence of various polyphenolic acetates (PA tested for their anti-mycobacterial activity. DAMC and DAMC-5-carboxylic acid was found to have MIC of 40μg/ml whereas DAMC-6-carboxylic acid was reported to have MIC value of 35μg/ml and for ellagic acid tetra acetate (EATA it was 60μg/ml. Previous work in our lab has led to discovery of a novel enzyme acetoxy drug: protein transacetylase (TAase, catalyzing transfer of acetyl group from various polyphenolic peracetate (PA to certain receptor proteins such as cytochromes P-450, NADPH cytochrome reductase, nitric oxide synthase (NOS

  5. Physiology and Genetics of Biogenic Methane-Production from Acetate

    Energy Technology Data Exchange (ETDEWEB)

    Sowers, Kevin R

    2013-04-04

    Biomass conversion catalyzed by methanogenic consortia is a widely available, renewable resource for both energy production and waste treatment. The efficiency of this process is directly dependent upon the interaction of three metabolically distinct groups of microorganisms; the fermentative and acetogenic Bacteria and the methanogenic Archaea. One of the rate limiting steps in the degradation of soluble organic matter is the dismutation of acetate, a predominant intermediate in the process, which accounts for 70 % or more of the methane produced by the methanogens. Acetate utilization is controlled by regulation of expression of carbon monoxide dehydrogensase (COdh), which catalyzes the dismutation of acetate. However, physiological and molecular factors that control differential substrate utilization have not been identified in these Archaea. Our laboratory has identified sequence elements near the promoter of the gene (cdh) encoding for COdh and we have confirmed that these sequences have a role in the in vivo expression of cdh. The current proposal focuses on identifying the regulatory components that interact with DNA and RNA elements, and identifying the mechanisms used to control cdh expression. We will determine whether expression is controlled at the level of transcription or if it is mediated by coordinate interaction of transcription initiation with other processes such as transcription elongation rate and differential mRNA stability. Utilizing recently sequenced methanosarcinal genomes and a DNA microarray currently under development genes that encode regulatory proteins and transcription factors will be identified and function confirmed by gene disruption and subsequent screening on different substrates. Functional interactions will be determined in vivo by assaying the effects of gene dosage and site-directed mutagenesis of the regulatory gene on the expression of a cdh::lacZ operon fusion. Results of this study will reveal whether this critical

  6. Acetate oxidation by syntrophic association between Geobacter sulfurreducens and a hydrogen-utilizing exoelectrogen.

    Science.gov (United States)

    Kimura, Zen-ichiro; Okabe, Satoshi

    2013-08-01

    Anodic microbial communities in acetate-fed microbial fuel cells (MFCs) were analyzed using stable-isotope probing of 16S rRNA genes followed by denaturing gradient gel electrophoresis. The results revealed that Geobacter sulfurreducens and Hydrogenophaga sp. predominated in the anodic biofilm. Although the predominance of Geobacter sp. as acetoclastic exoelectrogens in acetate-fed MFC systems has been often reported, the ecophysiological role of Hydrogenophaga sp. is unknown. Therefore, we isolated and characterized a bacterium closely related to Hydrogenophaga sp. (designated strain AR20). The newly isolated strain AR20 could use molecular hydrogen (H2), but not acetate, with carbon electrode as the electron acceptor, indicating that the strain AR20 was a hydrogenotrophic exoelectrogen. This evidence raises a hypothesis that acetate was oxidized by G. sulfurreducens in syntrophic cooperation with the strain AR20 as a hydrogen-consuming partner in the acetate-fed MFC. To prove this hypothesis, G. sulfurreducens strain PCA was cocultivated with the strain AR20 in the acetate-fed MFC without any dissolved electron acceptors. In the coculture MFC of G. sulfurreducens and strain AR20, current generation and acetate degradation were the highest, and the growth of strain AR20 was observed. No current generation, acetate degradation and cell growth occurred in the strain AR20 pure culture MFC. These results show for the first time that G. sulfurreducens can oxidize acetate in syntrophic cooperation with the isolated Hydrogenophaga sp. strain AR20, with electrode as the electron acceptor.

  7. Multiple sclerosis. Generic glatiramer acetate--a step toward cheaper MS drugs?

    DEFF Research Database (Denmark)

    Sørensen, Per Soelberg

    2016-01-01

    A randomized, double-blind, phase III trial of generic glatiramer acetate has shown equivalent efficacy and safety compared with the approved formulation, Copaxone. The impact of approval of generic glatiramer acetate, however, will mainly depend on the pricing of the drug.......A randomized, double-blind, phase III trial of generic glatiramer acetate has shown equivalent efficacy and safety compared with the approved formulation, Copaxone. The impact of approval of generic glatiramer acetate, however, will mainly depend on the pricing of the drug....

  8. Effects of acetate on Kluyveromyces marxianus DSM 5422 growth and metabolism.

    Science.gov (United States)

    Martynova, Jekaterina; Kokina, Agnese; Kibilds, Juris; Liepins, Janis; Scerbaka, Rita; Vigants, Armands

    2016-05-01

    Metabolically active cells produce a wide array of metabolites that can inhibit their growth. Acetate is a widely known preservative, and it is also produced by yeast cells during their growth. Kluyveromyces marxianus DSM 5422 is a promising yeast strain that could be employed in biotechnological processes, but the knowledge of its stress physiology is scarce. Here, we investigate the effects of acetate on growth and changes in cell population structure during adaptation to elevated concentrations of acetate in K. marxianus DSM 5422. Our results indicate that acetate inhibits growth in a pH-dependent manner and has pronounced effects if yeast is grown on lactose or galactose. When challenged with acetate, culture extends lag phase, during which cells adapt to elevated acetate concentrations, and growth reoccurs, albeit at a slower rate, when majority of the population is acetate resistant. Acetate resistance is maintained only if acetate is present in the media or if the culture has reached end of active growth phase. This study shows possible caveats in lactose fermentation with K. marxianus and gives a further perspective in non-conventional yeast applications in biotechnology.

  9. Vacuum ultraviolet and infrared spectra of condensed methyl acetate on cold astrochemical dust analogs

    Energy Technology Data Exchange (ETDEWEB)

    Sivaraman, B. [Space and Atmospheric Sciences Division, Physical Research Laboratory, Ahmedabad 380009 (India); Nair, B. G.; Mason, N. J. [Department of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Lo, J.-I.; Cheng, B.-M. [National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu Science Park, Hsinchu 30076, Taiwan (China); Kundu, S.; Davis, D.; Prabhudesai, V.; Krishnakumar, E. [Department of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Mumbai 400005 (India); Raja Sekhar, B. N., E-mail: bhala@prl.res.in [B-4, Indus-1, BARC Spectroscopy Lab at Indus-1, Atomic and Molecular Physics Division, BARC, Mumbai and RRCAT, Indore 452013 (India)

    2013-12-01

    Following the recent report of the first identification of methyl acetate (CH{sub 3}COOCH{sub 3}) in the interstellar medium (ISM), we have carried out vacuum ultraviolet (VUV) and infrared (IR) spectroscopy studies on methyl acetate from 10 K until sublimation in an ultrahigh vacuum chamber simulating astrochemical conditions. We present the first VUV and IR spectra of methyl acetate relevant to ISM conditions. Spectral signatures clearly showed molecular reorientation to have started in the ice by annealing the amorphous ice formed at 10 K. An irreversible phase change from amorphous to crystalline methyl acetate ice was found to occur between 110 K and 120 K.

  10. Effect of acetic acid on lipid accumulation by glucose-fed activated sludge cultures

    Energy Technology Data Exchange (ETDEWEB)

    Mondala, Andro; Hernandez, Rafael; French, Todd; McFarland, Linda; Sparks, Darrell; Holmes, William; Haque, Monica

    2012-01-01

    The effect of acetic acid, a lignocellulose hydrolysis by-product, on lipid accumulation by activated sludge cultures grown on glucose was investigated. This was done to assess the possible application of lignocellulose as low-cost and renewable fermentation substrates for biofuel feedstock production. Results: Biomass yield was reduced by around 54% at a 2 g L -1 acetic acid dosage but was increased by around 18% at 10 g L -1 acetic acid dosage relative to the control run. The final gravimetric lipid contents at 2 and 10 g L -1 acetic acid levels were 12.5 + 0.7% and 8.8 + 3.2% w/w, respectively, which were lower than the control (17.8 + 2.8% w/w). However, biodiesel yields from activated sludge grown with acetic acid (5.6 + 0.6% w/w for 2 g L -1 acetic acid and 4.2 + 3.0% w/w for 10 g L -1 acetic acid) were higher than in raw activated sludge (1-2% w/w). The fatty acid profiles of the accumulated lipids were similar with conventional plant oil biodiesel feedstocks. Conclusions: Acetic acid enhanced biomass production by activated sludge at high levels but reduced lipid production. Further studies are needed to enhance acetic acid utilization by activated sludge microorganisms for lipid biosynthesis.

  11. Acetate adaptation of clostridia tyrobutyricum for improved fermentation production of butyrate.

    Science.gov (United States)

    Jaros, Adam M; Rova, Ulrika; Berglund, Kris A

    2013-12-01

    Clostridium tyrobutyricum ATCC 25755 is an acidogenic bacterium capable of utilizing xylose for the fermentation production of butyrate. Hot water extraction of hardwood lingocellulose is an efficient method of producing xylose where autohydrolysis of xylan is catalysed by acetate originating from acetyl groups present in hemicellulose. The presence of acetic acid in the hydrolysate might have a severe impact on the subsequent fermentations. In this study the fermentation kinetics of C. tyrobutyricum cultures after being classically adapted for growth at 26.3 g/L acetate equivalents were studied. Analysis of xylose batch fermentations found that even in the presence of high levels of acetate, acetate adapted strains had similar fermentation kinetics as the parental strain cultivated without acetate. The parental strain exposed to acetate at inhibitory conditions demonstrated a pronounced lag phase (over 100 hours) in growth and butyrate production as compared to the adapted strain (25 hour lag) or non-inhibited controls (0 lag). Additional insight into the metabolic pathway of xylose consumption was gained by determining the specific activity of the acetate kinase (AK) enzyme in adapted versus control batches. AK activity was reduced by 63% in the presence of inhibitory levels of acetate, whether or not the culture had been adapted.

  12. [Cerebrospinal fluid pressure studies after the intravenous administration of the steroid narcotic, alphaxolone + alphadolone acetate (Althesin)].

    Science.gov (United States)

    Ekhart, E; List, W F; Vadon, P; Oberbauer, R

    1979-09-30

    The effect of alphaxalon + alphadolon-acetate on cerebrospinal fluid pressure (CSFP), mean arterial blood pressure (MPA), heart rate (BMP) and blood gases was investigated in 18 patients. Cerebral perfusion pressure (CPP) was calculated from the difference MAP minus CSFP. Alphaxalon + alphadolon-acetate lowered the normal CSFP and normalized ketamin induced increase of CSFP. Premedication with alphaxalon + alphadolon-acetate delayed the ketamin induced increase of CSFP, which returned to norm after a second dose of alphaxalon + alphadolon-acetate. This effect was seen despite elevation of pCO2 in all patients breathing spontaneously.

  13. Isotope fractionation during the anaerobic consumption of acetate by methanogenic and sulfate-reducing microorganisms

    Science.gov (United States)

    Gövert, D.; Conrad, R.

    2009-04-01

    During the anaerobic degradation of organic matter in anoxic sediments and soils acetate is the most important substrate for the final step in production of CO2 and/or CH4. Sulfate-reducing bacteria (SRB) and methane-producing archaea both compete for the available acetate. Knowledge about the fractionation of 13C/12C of acetate carbon by these microbial groups is still limited. Therefore, we determined carbon isotope fractionation in different cultures of acetate-utilizing SRB (Desulfobacter postgatei, D. hydrogenophilus, Desulfobacca acetoxidans) and methanogens (Methanosarcina barkeri, M. acetivorans). Including literature values (e.g., Methanosaeta concilii), isotopic enrichment factors (epsilon) ranged between -35 and +2 permil, possibly involving equilibrium isotope effects besides kinetic isotope effects. The values of epsilon were dependent on the acetate-catabolic pathway of the particular microorganism, the methyl or carboxyl position of acetate, and the relative availability or limitation of the substrate acetate. Patterns of isotope fractionation in anoxic lake sediments and rice field soil seem to reflect the characteristics of the microorganisms actively involved in acetate catabolism. Hence, it might be possible using environmental isotopic information to determine the type of microbial metabolism converting acetate to CO2 and/or CH4.

  14. Abilities of some higher plants to hydrolyze the acetates of phenols and aromatic-aliphatic alcohols

    Directory of Open Access Journals (Sweden)

    Agnieszka Mironowicz

    2014-01-01

    Full Text Available In the biotransformations carried out under the same conditions, the whole intact plants of Spirodela punctata, Nephrolepis exaltata, Cyrtomium falcatum, Nephrolepis cordifolia and the suspension cultures of Helianthus tuberosus, Daucus carota and Petunia hybrida hydrolyze (partially or totally the ester bonds of the acetates of phenols and aromatic-aliphatic alcohols and also the menthyl acetate. Nevertheless, the methyl esters of aromatic acids, structurally similar to the former substrates, do not undergo hydrolysis. At the same time, the viability of first four plants was observed for different levels of acetate concentration. The method of continuous preparative hydrolysis of the same acetates was worked out in Cyrtomium falcatum culture.

  15. Vinyl acetate induces intracellular acidification in mouse oral buccal epithelial cells.

    Science.gov (United States)

    Nakamoto, Tetsuji; Wagner, Mark; Melvin, James E; Bogdanffy, Matthew S

    2005-08-14

    Vinyl acetate exposure in drinking water has been associated with tumor formation in the upper gastrointestinal tract of rats and mice. One potential mechanism for inducing carcinogenesis involves acidification of the intracellular environment due to the metabolism of vinyl acetate to acetic acid. Prolonged intracellular acidification is thought to produce cytotoxic and/or mitogenic responses that are the sentinel pharmacodynamic steps toward cancer. To determine whether exposure to vinyl acetate affects the intracellular pH of intact oral cavity tissue, isolated mouse oral buccal epithelium was loaded with the pH-sensitive dye BCECF, and then exposed to vinyl acetate concentrations ranging from 10 to 1000 microM for up to 4 min. Extracellular vinyl acetate exposure induced a progressive intracellular acidification that was reversible upon removal of the vinyl acetate. The rate of the acidification was concentration-dependent and increased exponentially within the concentration range tested. The magnitude of the vinyl acetate-induced acidification was inhibited by pretreatment with the carboxylesterase inhibitor bis(p-nitrophenyl)phosphate. These results are consistent with the hypothesis that vinyl acetate contributes to the generation and progression of oral cavity tumors via a process of intracellular acidification. Such a process has been proposed to have practical dose-response thresholds below which the intracellular environment can be maintained within homeostatic bounds and the contribution of exposure to carcinogenic risk is negligible.

  16. The use of megestrol acetate in some feline dermatological problems.

    Science.gov (United States)

    Gosselin, Y; Chalifoux, A; Papageorges, M

    1981-12-01

    Twenty-one cats were treated with megestrol acetate because they were showing clinical signs associated with one of the following problems: eosinophilic ulcer, eosinophilic plaque, neurodermatitis, endocrine alopecia and miliary dermatitis. The dosage schedule was 5 mg orally per day per cat for seven days, then 5 mg every three days for 21 days. In all cats, we noted a good improvement of the lesions as soon as treatment was started. In 25% of the patients, one treatment schedule was sufficient to control the skin disease for at least 18 months. In the remaining 75%, two treatment schedules and/or a maintenance dosage had to be established.Side effects encountered were increased appetite, personality changes and depression.

  17. Cashew wine vinegar production: alcoholic and acetic fermentation

    Directory of Open Access Journals (Sweden)

    M. E. Silva

    2007-06-01

    Full Text Available Cashew wine of demi-sec grade was produced in a stirred batch reactor. The kinetic parameters obtained for cashew wine fermentation were Y X/S=0.061, Y P/S=0.3 and µmax=0.16 h-1. The yield and the productivity of cashew wine were 57.7% and 0.78 g/Lh respectively. A 2² factorial experimental design was used for the cashew wine vinegar fermentation optimization study. The cashew wine vinegar process optimization ranges found for initial concentrations of ethanol and acetic acid as independent variables were 4.8 to 6.0% and 1.0 to 1.3% respectively.

  18. Ignition of magnetic deflagration in Mn12 acetate

    Science.gov (United States)

    McHugh, Sean; Jaafar, R.; Sarachik, M. P.; Myasoedov, Y.; Finkler, A.; Shtrikman, H.; Zeldov, E.; Bagai, R.; Christou, G.

    2008-03-01

    We study the conditions for the ignition of two types of magnetic avalanches in the molecular magnet Mn12-acetate corresponding to the major species and a fast-relaxing minor species. The minor component, which has a lower anisotropy barrier, exists in these crystals at the level of 5-7%. The ignition temperatures are measured using small (30 x30 μm^2) Ge thermometers. In addition, the magnetization dynamics are measured using an array of Hall sensors of comparable size. Various aspects of the ignition will be discussed, including: the reduction of the ignition threshold due to quantum tunneling, the catalytic effect of the minor species, and the shift of the ignition point as a function of external magnetic field. The work at City College was supported by NSF grant DMR-00451605. E. Z. acknowledges the support of the Israel Ministry of Science, Culture and Sports. Support for G. C. was provided by NSF grant CHE-0414555.

  19. Liquid phase ozonation of cyclohexanol using acetic acid as solvent

    Energy Technology Data Exchange (ETDEWEB)

    Encinar, J.M.; Beltran, F.J. (Departamento de Ingeneria Quimica y Energetica. Facultad de Ciencias. Badajoz (Spain)); Frades, J.M. (Departamento de Ingenieria Quimica. E.U.P. Almaden (Spain))

    1994-01-01

    The liquid phase oxidation of cyclohexanol in an acetic acid medium using a mixture of oxygen and ozone has been studied in a laboratory semi batch reactor. The influence of temperature, ozone partial pressure, initial concentration of cyclohexanol on its conversion and yield and distribution of products has been observed. Under the experimental conditions investigated formation of peroxydic compounds and mono basic acids was not relevant; the major products obtained were cyclohexanone and adipic and glutaric acids although analytical chromatograms revealed the presence of other products unidentified. Formation of these products is qualitatively explained by means of a chain-radical mechanism. Finally, it is proposed an empirical kinetic equation which relates the variables mentioned above with the reaction rates. This equation reproduces the experimental results with deviations less than 10%. (Author) 21 refs.

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

    Science.gov (United States)

    Mamlouk, Dhouha; Gullo, Maria

    2013-12-01

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

  1. Hydroxide as general base in the saponification of ethyl acetate.

    Science.gov (United States)

    Mata-Segreda, Julio F

    2002-03-13

    The second-order rate constant for the saponification of ethyl acetate at 30.0 degrees C in H(2)O/D(2)O mixtures of deuterium atom fraction n (a proton inventory experiment) obeys the relation k(2)(n) = 0.122 s(-1) M(-1) (1 - n + 1.2n) (1 - n + 0.48n)/(1 - n + 1.4n) (1 - n + 0.68n)(3). This result is interpreted as a process where formation of the tetrahedral intermediate is the rate-determining step and the transition-state complex is formed via nucleophilic interaction of a water molecule with general-base assistance from hydroxide ion, opposite to the direct nucleophilic collision commonly accepted. This mechanistic picture agrees with previous heavy-atom kinetic isotope effect data of Marlier on the alkaline hydrolysis of methyl formate.

  2. Ionic liquid mediated esterification of alcohol with acetic acid

    Institute of Scientific and Technical Information of China (English)

    Beilei ZHOU; Yanxiong FANG; Hao GU; Saidan ZHANG; Baohua HUANG; Kun ZHANG

    2009-01-01

    Highly efficient esterification of alcohols with acetic acid by using a Bransted acidic ionic liquid, i.e., 1-methyl-2-pyrrolidonium hydrogen sulfate ([Hnmp]HSo4), as catalyst has been realized. The turnover numbers (TON) were able to reach up to 11000 and turnover frequency (TOF) was 846. The catalytic system is suitable for the esterification of long chain aliphatic alcohols, benzyl alcohol and cyclohexanol with good yields of esters. The procedure of separating the product and catalyst is simple, and the catalyst could be reused. [Hnmp]HSO4 had much weaker corrosiveness than H2SO4. The corrosive rate of H2SO4 was 400 times more than that of [Hnmp]HSO4 to stainless steel.

  3. Purification and Characterization of An Alkaline Protease from Acetes chinensis

    Institute of Scientific and Technical Information of China (English)

    XU Jiachao; LIU Xin; LI Zhaojie; XU Jie; XUE Changhu; GAO Xin

    2005-01-01

    An alkaline protease from Acetes chinensis was purified and characterized in this study. The steps of purification include ammonium sulfate precipitation, ion-exchange chromatography with Q-sepharose Fast Flow, gel filtration chromatography with S300 and the second ion-exchange chromatography with Q-sepharose Fast Flow. The protease was isolated and purified, which was present and active on protein substrates (azocasein and casein). The specific protease activity was 17.15folds and the recovery was 4.67. The molecular weight of the protease was estimated at 23.2 kD by SDS-PAGE. With azocasein as the susbstrate, the optimal temperature was 55 ℃ and the optimal pH value was 5.5. Ion Ca2+ could enhance the proteolytic activity of the protease, while Cu2+ , EDTA and PMSF could inhibit its activity.

  4. Oxygen Permeability of Polypropylene Containing Polyisobutene with Magnesium Acetate

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The oxygen permeabilities of polypropylene films are reduced by adding a minor percentage of a polyisobutene ionomer. The polyisobutene ionomers were prepared by in situ salt exchange of magnesium acetate with maleated polyisobutenes of commercially available low relative molecular mass. The more polar magnesium salts aided phase separation during crystallization from the molten polypropylene mixture. Scanning electron microscope photographs revealed that the polyisobutene ionomer is largely concentrated in the amorphous regions between the polypropylene spherulites, where the ionomer tends to concentrate during crystallization. The influence of the polyisobutene ionomer on the oxygen permeability of polypropylene was found to be slightly dependent upon the relative molecular mass of the polyisobutene precursor. Under optimum conditions, the oxygen permeability of polypropylene is reduced by 20% with only 1% additive.

  5. New Biopolymer Nanoparticles Improve the Solubility of Lipophilic Megestrol Acetate

    Directory of Open Access Journals (Sweden)

    Malwina Lachowicz

    2016-02-01

    Full Text Available As many substances are poorly soluble in water and thus possess decreased bioavailability, creating orally administered forms of these substances is a challenge. The objective of this study was to determine whether the solubility of megestrol acetate, a Biopharmaceutical Classification System (BCS class II drug, can be improved by using a newly-synthesized surfactant (Rofam 70: a rapeseed methyl ester ethoxylate and compare it with two references surfactants (Tween 80, Pluronic F68 at three different pH values. Spectrophotometry was used to compare the solubility profiles in the presence of three tested surfactants at pH 5.0, 7.4 and 9.0. Rapeseed methyl ester ethoxylate was found to improve the solubility of the BCS Class II drug and increase its bioavailability; It increased drug solubility more effectively than Pluronic F68. Its cytotoxicity results indicate its possible value as a surfactant in Medicine and Pharmacy.

  6. Acetylation of barnyardgrass starch with acetic anhydride under iodine catalysis.

    Science.gov (United States)

    Bartz, Josiane; Goebel, Jorge Tiago; Giovanaz, Marcos Antônio; Zavareze, Elessandra da Rosa; Schirmer, Manoel Artigas; Dias, Alvaro Renato Guerra

    2015-07-01

    Barnyardgrass (Echinochloa crus-galli) is an invasive plant that is difficult to control and is found in abundance as part of the waste of the paddy industry. In this study, barnyardgrass starch was extracted and studied to obtain a novel starch with potential food and non-food applications. We report some of the physicochemical, functional and morphological properties as well as the effect of modifying this starch with acetic anhydride by catalysis with 1, 5 or 10mM of iodine. The extent of the introduction of acetyl groups increased with increasing iodine levels as catalyst. The shape of the granules remained unaltered, but there were low levels of surface corrosion and the overall relative crystallinity decreased. The pasting temperature, enthalpy and other gelatinisation temperatures were reduced by the modification. There was an increase in the viscosity of the pastes, except for the peak viscosity, which was strongly reduced in 10mM iodine.

  7. Antimicrobial Lemongrass Essential Oil-Copper Ferrite Cellulose Acetate Nanocapsules.

    Science.gov (United States)

    Liakos, Ioannis L; Abdellatif, Mohamed H; Innocenti, Claudia; Scarpellini, Alice; Carzino, Riccardo; Brunetti, Virgilio; Marras, Sergio; Brescia, Rosaria; Drago, Filippo; Pompa, Pier Paolo

    2016-04-20

    Cellulose acetate (CA) nanoparticles were combined with two antimicrobial agents, namely lemongrass (LG) essential oil and Cu-ferrite nanoparticles. The preparation method of CA nanocapsules (NCs), with the two antimicrobial agents, was based on the nanoprecipitation method using the solvent/anti-solvent technique. Several physical and chemical analyses were performed to characterize the resulting NCs and to study their formation mechanism. The size of the combined antimicrobial NCs was found to be ca. 220 nm. The presence of Cu-ferrites enhanced the attachment of LG essential oil into the CA matrix. The magnetic properties of the combined construct were weak, due to the shielding of Cu-ferrites from the polymeric matrix, making them available for drug delivery applications where spontaneous magnetization effects should be avoided. The antimicrobial properties of the NCs were significantly enhanced with respect to CA/LG only. This work opens novel routes for the development of organic/inorganic nanoparticles with exceptional antimicrobial activities.

  8. Purification and characterization of an alkaline protease from Acetes chinensis

    Science.gov (United States)

    Xu, Jiachao; Liu, Xin; Li, Zhaojie; Xu, Jie; Xue, Changhu; Gao, Xin

    2005-07-01

    An alkaline protease from Acetes chinensis was purified and characterized in this study. The steps of purification include ammonium sulfate precipitation, ion-exchange chromatography with Q-sepharose Fast Flow, gel filtration chromatography with S300 and the second ion-exchange chromatography with Q-sepharose Fast Flow. The protease was isolated and purified, which was present and active on protein substrates (azocasein and casein). The specific protease activity was 17.15 folds and the recovery was 4.67. The molecular weight of the protease was estimated at 23.2 kD by SDS-PAGE. With azocasein as the susbstrate, the optimal temperature was 55°C and the optimal pH value was 5.5. Ion Ca2+ could enhance the proteolytic activity of the protease, while Cu2+, EDTA and PMSF could inhibit its activity.

  9. UV recording with vinyl acetate and muicle dye film

    Science.gov (United States)

    Toxqui-Lopez, S.; Olivares-Pérez, A.; Santacruz-Vazquez, V.; Fuentes-Tapia, I.; Ordoñez-Padilla, J.

    2015-03-01

    Nowadays, there are many types of holographic recording medium some of them are photopolymer systems that generally consist of a polymeric host matrix, photopolymerizable momomer, photosensitizing dye and charge transfer agent but some of them have an undesirable feature, the toxicity of their components. Therefore, the present research study material recording, vinyl acetate is selected as polymeric matrix and natural dye from "muicle plant" is used as the photoinitiation these components are not toxic. The films are fabricated using gravity settling method at room temperature by this method, uniform films is obtained with good optical quality. To characterize the medium, been obtained when the coherent reed light (632.8 nm) was sent normally to the grating.

  10. Regioselective Alcoholysis of Silychristin Acetates Catalyzed by Lipases

    Directory of Open Access Journals (Sweden)

    Eva Vavříková

    2015-05-01

    Full Text Available A panel of lipases was screened for the selective acetylation and alcoholysis of silychristin and silychristin peracetate, respectively. Acetylation at primary alcoholic group (C-22 of silychristin was accomplished by lipase PS (Pseudomonas cepacia immobilized on diatomite using vinyl acetate as an acetyl donor, whereas selective deacetylation of 22-O-acetyl silychristin was accomplished by Novozym 435 in methyl tert-butyl ether/ n-butanol. Both of these reactions occurred without diastereomeric discrimination of silychristin A and B. Both of these enzymes were found to be capable to regioselective deacetylation of hexaacetyl silychristin to afford penta-, tetra- and tri-acetyl derivatives, which could be obtained as pure synthons for further selective modifications of the parent molecule.

  11. A pharmacokinetic study of roxatidine acetate in chronic renal failure.

    Science.gov (United States)

    Lameire, N; Rosenkranz, B; Maass, L; Brockmeier, D

    1988-01-01

    The pharmacokinetics of a single oral dose of roxatidine acetate 150 mg were studied in 31 patients with varying degrees of chronic renal failure. The patients were divided into 5 groups according to their creatinine clearance (Clcr): controls (Clcr 94.5 +/- 13.9 ml/min; n = 6); mild chronic renal failure (Clcr 47 +/- 6 ml/min; n = 4); moderate chronic renal failure (Clcr 27.3 +/- 3.1 ml/min; n = 4); severe chronic renal failure (Clcr 12.8 +/- 1.4 ml/min; n = 5) and uraemia (Clcr 6.6 +/- 0.6 ml/min; n = 12). Serum and urine samples were analysed with capillary gas chromatography to measure the salt of the desacetyl metabolite of roxatidine acetate (roxatidine). The terminal half-life was 6.02 +/- 0.31 hours in controls and 7.35 +/- 0.57, 9.3 +/- 0.83, 14.6 +/- 3.7 and 18.10 +/- 2.77 hours, respectively, in the 4 other groups, with progressively decreasing creatinine clearance. Maximum serum concentration and time to maximum serum concentration rose from 816 +/- 75 ng/ml and 2.08 +/- 0.22 hours, respectively, in controls to 1364.7 +/- 156 ng/ml and 4.05 +/- 0.47 hours, respectively, in uraemic patients. Relative total clearance progressively decreased with decreasing glomerular filtration rate (GFR) [from 353.6 +/- 26 ml/min in controls to 90.31 +/- 12.2 ml/min in patients with uraemia]. Renal clearance decreased from a control of 243.9 +/- 56 ml/min to 12.32 +/- 0.18 ml/min in uraemic patients. A linear correlation between creatinine clearance and both relative total clearance and renal drug clearance was noted.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Nomegestrol acetate-17b-estradiol for oral contraception

    Directory of Open Access Journals (Sweden)

    Burke A

    2013-06-01

    Full Text Available Anne Burke Johns Hopkins University School of Medicine, Baltimore, MD, USAAbstract: Oral contraceptives remain a popular method of contraception over 50 years after their introduction. While safe and effective for many women, the failure rate of oral contraception is about 8%. Concerns about the risk of venous thromboembolism continue to drive the search for the safest oral contraceptive formulations. The oral contraceptive NOMAC-E2 contains nomegestrol acetate (NOMAC 2.5 mg + 17b-estradiol (E2 1.5 mg. The approved dosing regimen is 24 days of active hormone, followed by a 4-day hormone-free interval. NOMAC is a progestin derived from testosterone, which has high bioavailability, rapid absorption, and a long half-life. Estradiol, though it has a lower bioavailability, has been successfully combined with NOMAC in a monophasic oral contraceptive. Two recently published randomized controlled trials demonstrate that NOMAC-E2 is an effective contraceptive, with a Pearl Index less than one pregnancy per 100 woman-years. The bleeding pattern on NOMAC-E2 is characterized by fewer bleeding/spotting days, shorter withdrawal bleeds, and a higher incidence of amenorrhea than the comparator oral contraceptive containing drospirenone and ethinyl estradiol. The adverse event profile appears to be acceptable. Few severe adverse events were reported in the randomized controlled trials. The most common adverse events were irregular bleeding, acne, and weight gain. Preliminary studies suggest that NOMAC-E2 does not seem to have negative effects on hemostatic and metabolic parameters. While no one oral contraceptive formulation is likely to be the optimum choice for all women, NOMAC-E2 is a formulation with effectiveness comparable with that of other oral contraceptives, and a reassuring safety profile.Keywords: oral contraception, nomegestrol acetate, estradiol

  13. Effect of lead acetate on neurobehavioral development of rats

    Directory of Open Access Journals (Sweden)

    Mello C.F.

    1998-01-01

    Full Text Available We investigated the effects of lead exposure during the pre- and postnatal period on the neurobehavioral development of female Wistar rats (70-75 days of age, 120-150 g using a protocol of lead intoxication that does not affect weight gain. Wistar rats were submitted to lead acetate intoxication by giving their dams 1.0 mM lead acetate. Control dams received deionized water. Growth and neuromotor development were assessed by monitoring daily the following parameters in 20 litters: body weight, ear unfolding, incisor eruption, eye opening, righting, palmar grasp, negative geotaxis, cliff avoidance and startle reflex. Spontaneous alternation was assessed on postnatal day 17 using a T maze. The animals' ability to equilibrate on a beaker rim was measured on postnatal day 19. Lead intoxication was confirmed by measuring renal, hepatic and cerebral lead concentration in dams and litters. Lead treatment hastened the day of appearance of the following parameters: eye opening (control: 13.5 ± 0.6, N = 88; lead: 12.9 ± 0.6, N = 72; P<0.05, startle reflex (control: 13.0 ± 0.8, N = 88; lead: 12.0 ± 0.7, N = 72; P<0.05 and negative geotaxis. On the other hand, spontaneous alternation performance was hindered in lead-exposed animals (control: 37.6 ± 19.7; lead: 57.5 ± 28.3% of alternating animals; P<0.05. These results suggest that lead exposure without concomitant undernutrition alters rat development, affecting specific subsets of motor skills.

  14. Recent advances in nitrogen-fixing acetic acid bacteria.

    Science.gov (United States)

    Pedraza, Raúl O

    2008-06-30

    Nitrogen is an essential plant nutrient, widely applied as N-fertilizer to improve yield of agriculturally important crops. An interesting alternative to avoid or reduce the use of N-fertilizers could be the exploitation of plant growth-promoting bacteria (PGPB), capable of enhancing growth and yield of many plant species, several of agronomic and ecological significance. PGPB belong to diverse genera, including Azospirillum, Azotobacter, Herbaspirillum, Bacillus, Burkholderia, Pseudomonas, Rhizobium, and Gluconacetobacter, among others. They are capable of promoting plant growth through different mechanisms including (in some cases), the biological nitrogen fixation (BNF), the enzymatic reduction of the atmospheric dinitrogen (N(2)) to ammonia, catalyzed by nitrogenase. Aerobic bacteria able to oxidize ethanol to acetic acid in neutral or acid media are candidates of belonging to the family Acetobacteraceae. At present, this family has been divided into ten genera: Acetobacter, Gluconacetobacter, Gluconobacter, Acidomonas, Asaia, Kozakia, Saccharibacter, Swaminathania, Neoasaia, and Granulibacter. Among them, only three genera include N(2)-fixing species: Gluconacetobacter, Swaminathania and Acetobacter. The first N(2)-fixing acetic acid bacterium (AAB) was described in Brazil. It was found inside tissues of the sugarcane plant, and first named as Acetobacter diazotrophicus, but then renamed as Gluconacetobacter diazotrophicus. Later, two new species within the genus Gluconacetobacter, associated to coffee plants, were described in Mexico: G. johannae and G. azotocaptans. A salt-tolerant bacterium named Swaminathania salitolerans was found associated to wild rice plants. Recently, N(2)-fixing Acetobacter peroxydans and Acetobacter nitrogenifigens, associated with rice plants and Kombucha tea, respectively, were described in India. In this paper, recent advances involving nitrogen-fixing AAB are presented. Their natural habitats, physiological and genetic aspects

  15. Vinyl acetate monomer (VAM) genotoxicity profile: relevance for carcinogenicity.

    Science.gov (United States)

    Albertini, Richard J

    2013-09-01

    Vinyl acetate monomer (VAM) is a site-of-contact carcinogen in rodents. It is also DNA reactive and mutagenic, but only after its carboxylesterase mediated conversion to acetaldehyde (AA), a metabolic reaction that also produces acetic acid and protons. As VAM's mutagenic metabolite, AA is normally produced endogenously; detoxification by aldehyde dehydrogenase (ALDH) is required to maintain intra-cellular AA homeostasis. This review examines VAM's overall genotoxicity, which is due to and limited by AA, and the processes leading to mutation induction. VAM and AA have both been universally negative in mutation studies in bacteria but both have tested positive in several in vitro studies in higher organisms that usually employed high concentrations of test agents. Recently however, in vitro studies evaluating submillimolar concentrations of VAM or AA have shown threshold dose-responses for mutagenicity in human cultured cells. Neither VAM nor AA induced systemic mutagenicity in in vivo studies in metabolically competent mice when tested at non-lethal doses while treatments of animals deficient in aldehyde dehydrogenase (Aldh in animals) did induce both gene and chromosome level mutations. The results of several studies have reinforced the critical role for aldehyde dehydrogenase 2 (ALDH2 in humans) in limiting AA's (and therefore VAM's) mutagenicity. The overall aim of this review of VAM's mutagenic potential through its AA metabolite is to propose a mode of action (MOA) for VAM's site-of-contact carcinogenesis that incorporates the overall process of mutation induction that includes both background mutations due to endogenous AA and those resulting from exogenous exposures.

  16. The influence of surface oxygen and hydroxyl groups on the dehydrogenation of ethylene, acetic acid and hydrogenated vinyl acetate on pure Pd(1 0 0): A DFT study

    Science.gov (United States)

    Huang, Yanping; Dong, Xiuqin; Yu, Yingzhe; Zhang, Minhua

    2016-12-01

    On the basis of a Langmuir-Hinshelwood-type mechanism, the dehydrogenation of ethylene, acetic acid and hydrogenated vinyl acetate (VAH) on pure Pd(1 0 0) with surface oxygen atoms (Os) and hydroxyl groups (OHs) was studied with density functional theory (DFT) method. Our calculation results show that both Os and OHs can consistently reduce the activation energies of dehydrogenation of ethylene, acetic acid and VAH to some degree with only one exception that OHs somehow increase the activation energy of VAH. Based on Langmuir-Hinshelwood mechanism, the three dehydrogenation reactions in presence of surface Os and OHs are almost consistently favored, compared with the corresponding processes on clean Pd(1 0 0) surfaces, and thus a Langmuir-Hinshelwood-type mechanism may not be excluded beforehand when investigating the microscopic performance of the oxygen-assisted vinyl acetate synthesis on Pd(1 0 0) catalysts.

  17. Low and high acetate amendments are equally as effective at promoting complete dechlorination of trichloroethylene (TCE).

    Science.gov (United States)

    Wei, Na; Finneran, Kevin T

    2013-06-01

    Experiments with trichloroethylene-contaminated aquifer material demonstrated that TCE, cis-DCE, and VC were completely degraded with concurrent Fe(III) or Fe(III) and sulfate reduction when acetate was amended at stoichiometric concentration; competing TEAPs did not inhibit ethene production. Adding 10× more acetate did not increase the rate or extent of TCE reduction, but only increased methane production. Enrichment cultures demonstrated that ~90 μM TCE or ~22 μM VC was degraded primarily to ethene within 20 days with concurrent Fe(III) or Fe(III) + sulfate reduction. The dechlorination rates were comparable between the low and high acetate concentrations (0.36 vs 0.34 day(-1), respectively), with a slightly slower rate in the 10× acetate amended incubations. Methane accumulated to 13.5 (±0.5) μmol/tube in the TCE-degrading incubations with 10× acetate, and only 1.4 (±0.1) μmol/tube with low acetate concentration. Methane accumulated to 16 (±1.5) μmol/tube in VC-degrading enrichment with 10× acetate and 2 (±0.1) μmol/tube with stoichiometric acetate. The estimated fraction of electrons distributed to methanogenesis increased substantially when excessive acetate was added. Quantitative PCR analysis indicated that 10× acetate did not enhance Dehalococcoides biomass but rather increased the methanogen abundance by nearly one order of magnitude compared to that with stoichiometric acetate. The data suggest that adding low levels of substrate may be equally if not more effective as high concentrations, without producing excessive methane. This has implications for field remediation efforts, in that adding excess electron donor may not benefit the reactions of interest, which in turn will increase treatment costs without direct benefit to the stakeholders.

  18. Thermal decarboxylation of acetate. Part I. The kinetics and mechanism of reaction in aqueous solution

    Science.gov (United States)

    Palmer, Donald A.; Drummond, S. E.

    1986-05-01

    In an effort to understand the kinetics of the thermal decarboxylation of acetate and the role of catalysis, a series of laboratory experiments were conducted to measure the rate constants for the decomposition of acetate (acetic acid and sodium acetate) in the presence of titanium, silica, stainless steel, gold, and magnetite. Activation energies for decarboxylation of acetic acid and acetate ion range from about 8 kcal mol -1 in stainless steel vessels to 69 kcal mol -1 in silica tubes. Extrapolated rate constants at 100°C for acetic acid differ by more than fourteen orders of magnitude between the experiments conducted in stainless steel and the catalytically least active titanium vessels. Gold and titanium were the least active catalysts for the acetic acid substrate, while stainless steel, silica, and magnetite showed marked catalytic effects. Methane and carbon dioxide were the predominant reaction products of most of these experiments, although mass spectrometric analyses of the gas phase revealed concentrations of carbon monoxide and hydrocarbons (apparent mass range from 29 to 56) amounting to as much as 55 mole percent of the total volatile products, depending on the catalyst. The reactions were generally first order in acetic acid or acetate ion, except for those involving the acid over silica and magnetite which were zero order. These results and the observed effects of variations in surface area are rationalized in terms of changes in the mode of surface catalysis. The mechanistic assignment is simplified by the existence of three unique straight lines on an isokinetic plot ( i.e., activation enthalpy versus activation entropy) which fit all the respective first- and zeroorder reactions. The results described here provide the nucleus for the discussion in Part II of the role of acetate in the primary migration of methane and the transportation of metals in hydrothermal solutions.

  19. Transports of acetate and haloacetate in Burkholderia species MBA4 are operated by distinct systems

    Directory of Open Access Journals (Sweden)

    Su Xianbin

    2012-11-01

    Full Text Available Abstract Background Acetate is a commonly used substrate for biosynthesis while monochloroacetate is a structurally similar compound but toxic and inhibits cell metabolism by blocking the citric acid cycle. In Burkholderia species MBA4 haloacetate was utilized as a carbon and energy source for growth. The degradation of haloacid was mediated by the production of an inducible dehalogenase. Recent studies have identified the presence of a concomitantly induced haloacetate-uptake activity in MBA4. This uptake activity has also been found to transport acetate. Since acetate transporters are commonly found in bacteria it is likely that haloacetate was transported by such a system in MBA4. Results The haloacetate-uptake activity of MBA4 was found to be induced by monochloroacetate (MCA and monobromoacetate (MBA. While the acetate-uptake activity was also induced by MCA and MBA, other alkanoates: acetate, propionate and 2-monochloropropionate (2MCPA were also inducers. Competing solute analysis showed that acetate and propionate interrupted the acetate- and MCA- induced acetate-uptake activities. While MCA, MBA, 2MCPA, and butyrate have no effect on acetate uptake they could significantly quenched the MCA-induced MCA-uptake activity. Transmembrane electrochemical potential was shown to be a driving force for both acetate- and MCA- transport systems. Conclusions Here we showed that acetate- and MCA- uptake in Burkholderia species MBA4 are two transport systems that have different induction patterns and substrate specificities. It is envisaged that the shapes and the three dimensional structures of the solutes determine their recognition or exclusion by the two transport systems.

  20. Citric acid cycle in the hyperthermophilic archaeon Pyrobaculum islandicum grown autotrophically, heterotrophically, and mixotrophically with acetate.

    Science.gov (United States)

    Hu, Yajing; Holden, James F

    2006-06-01

    The hyperthermophilic archaeon Pyrobaculum islandicum uses the citric acid cycle in the oxidative and reductive directions for heterotrophic and autotrophic growth, respectively, but the control of carbon flow is poorly understood. P. islandicum was grown at 95 degrees C autotrophically, heterotrophically, and mixotrophically with acetate, H2, and small amounts of yeast extract and with thiosulfate as the terminal electron acceptor. The autotrophic growth rates and maximum concentrations of cells were significantly lower than those in other media. The growth rates on H2 and 0.001% yeast extract with and without 0.05% acetate were the same, but the maximum concentration of cells was fourfold higher with acetate. There was no growth with acetate if 0.001% yeast extract was not present, and addition of H2 to acetate-containing medium greatly increased the growth rates and maximum concentrations of cells. P. islandicum cultures assimilated 14C-labeled acetate in the presence of H2 and yeast extract with an efficiency of 55%. The activities of 11 of 19 enzymes involved in the central metabolism of P. islandicum were regulated under the three different growth conditions. Pyruvate synthase and acetate:coenzyme A (CoA) ligase (ADP-forming) activities were detected only in heterotrophically grown cultures. Citrate synthase activity decreased in autotrophic and acetate-containing cultures compared to the activity in heterotrophic cultures. Acetylated citrate lyase, acetate:CoA ligase (AMP forming), and phosphoenolpyruvate carboxylase activities increased in autotrophic and acetate-containing cultures. Citrate lyase activity was higher than ATP citrate synthase activity in autotrophic cultures. These data suggest that citrate lyase and AMP-forming acetate:CoA ligase, but not ATP citrate synthase, work opposite citrate synthase to control the direction of carbon flow in the citric acid cycle.

  1. Transcriptome analysis of acetic-acid-treated yeast cells identifies a large set of genes whose overexpression or deletion enhances acetic acid tolerance.

    Science.gov (United States)

    Lee, Yeji; Nasution, Olviyani; Choi, Eunyong; Choi, In-Geol; Kim, Wankee; Choi, Wonja

    2015-08-01

    Acetic acid inhibits the metabolic activities of Saccharomyces cerevisiae. Therefore, a better understanding of how S. cerevisiae cells acquire the tolerance to acetic acid is of importance to develop robust yeast strains to be used in industry. To do this, we examined the transcriptional changes that occur at 12 h post-exposure to acetic acid, revealing that 56 and 58 genes were upregulated and downregulated, respectively. Functional categorization of them revealed that 22 protein synthesis genes and 14 stress response genes constituted the largest portion of the upregulated and downregulated genes, respectively. To evaluate the association of the regulated genes with acetic acid tolerance, 3 upregulated genes (DBP2, ASC1, and GND1) were selected among 34 non-protein synthesis genes, and 54 viable mutants individually deleted for the downregulated genes were retrieved from the non-essential haploid deletion library. Strains overexpressing ASC1 and GND1 displayed enhanced tolerance to acetic acid, whereas a strain overexpressing DBP2 was sensitive. Fifty of 54 deletion mutants displayed enhanced acetic acid tolerance. Three chosen deletion mutants (hsps82Δ, ato2Δ, and ssa3Δ) were also tolerant to benzoic acid but not propionic and sorbic acids. Moreover, all those five (two overexpressing and three deleted) strains were more efficient in proton efflux and lower in membrane permeability and internal hydrogen peroxide content than controls. Individually or in combination, those physiological changes are likely to contribute at least in part to enhanced acetic acid tolerance. Overall, information of our transcriptional profile was very useful to identify molecular factors associated with acetic acid tolerance.

  2. Modification of wheat starch with succinic acid/acetic anhydride and azelaic acid/acetic anhydride mixtures I. Thermophysical and pasting properties.

    Science.gov (United States)

    Subarić, Drago; Ačkar, Durđica; Babić, Jurislav; Sakač, Nikola; Jozinović, Antun

    2014-10-01

    The aim of this research was to investigate the influence of modification with succinic acid/acetic anhydride and azelaic acid/acetic anhydride mixtures on thermophysical and pasting properties of wheat starch. Starch was isolated from two wheat varieties and modified with mixtures of succinic acid and acetic anhydride, and azelaic acid and acetic anhydride in 4, 6 and 8 % (w/w). Thermophysical, pasting properties, swelling power, solubility and amylose content of modified starches were determined. The results showed that modifications with mixtures of afore mentioned dicarboxylic acids with acetic anhydride decreased gelatinisation and pasting temperatures. Gelatinisation enthalpy of Golubica starch increased, while of Srpanjka starch decreased by modifications. Retrogradation after 7 and 14 day-storage at 4 °C decreased after modifications of both starches. Maximum, hot and cold paste viscosity of both starches increased, while stability during shearing at high temperatures decreased. % setback of starches modified with azelaic acid/acetic anhydride mixture decreased. Swelling power and solubility of both starches increased by both modifications.

  3. Electron attachment and electron ionization of acetic acid clusters embedded in helium nanodroplets

    NARCIS (Netherlands)

    da Silva, F. Ferreira; Jaksch, S.; Martins, G.; Dang, H. M.; Dampc, M.; Denifl, S.; Maerk, T. D.; Limao-Vieira, P.; Liu, J.; Yang, S.; Ellis, A. M.; Scheier, P.

    2009-01-01

    The effect of incident electrons on acetic acid clusters is explored for the first time. The acetic acid clusters are formed inside liquid helium nanodroplets and both cationic and anionic products ejected into the gas phase are detected by mass spectrometry. The cation chemistry (induced by electro

  4. Preparation of Ethylene Glycol Monoethyl Ether Acetate Using a Tubular Reactor

    Institute of Scientific and Technical Information of China (English)

    蔡振云; 卢祖国; 李小波

    2003-01-01

    Ethylene glycol monoethyl ether acetate (EGEA), an excellent solvent, is prepared with ethylene oxide (EO) and ethyl acetate (EA) in a tubular reactor under suitable reaction condition. The single circulation yield can reach 81%. This technology is not only safe but also makes it possible to continuously produce EGEA in industry,with low content of high boiling point by-products.

  5. Multiple sclerosis. Generic glatiramer acetate--a step toward cheaper MS drugs?

    Science.gov (United States)

    Sørensen, Per Soelberg

    2016-01-01

    A randomized, double-blind, phase III trial of generic glatiramer acetate has shown equivalent efficacy and safety compared with the approved formulation, Copaxone. The impact of approval of generic glatiramer acetate, however, will mainly depend on the pricing of the drug.

  6. Comparison of acetate tape impression with squeezing versus skin scraping for the diagnosis of canine demodicosis.

    Science.gov (United States)

    Pereira, A V; Pereira, S A; Gremião, I D F; Campos, M P; Ferreira, A M R

    2012-11-01

    This study compared the sensitivity of acetate tape impression and skin squeezing with that of deep skin scraping for the diagnosis of demodicosis in dogs. Demodex canis was detected in 100% of acetate tape impressions obtained after skin squeezing and in 90% of deep skin scrapings. There was a significant difference (P scraping and is an alternative diagnostic method for canine demodicosis.

  7. 21 CFR 524.1484i - Neomycin sulfate, hydrocortisone acetate, sterile ointment.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Neomycin sulfate, hydrocortisone acetate, sterile... NEW ANIMAL DRUGS § 524.1484i Neomycin sulfate, hydrocortisone acetate, sterile ointment. (a) Specifications. The drug contains 5 milligrams of neomycin sulfate, equivalent to 3.5 milligrams of neomycin...

  8. Novel ketene N,S-acetals : synthesis and reactions of 1-isocyano-1-arylthioethenes.

    NARCIS (Netherlands)

    Hemert, Antonius Wilhelmus van

    1987-01-01

    This thesis deals with a new type of ketene N,S-acetals. It concerns compounds of the general structure 62, in which an arylthio group and an isocyano group are attached to the same carbon atom of a C,C double bond. These compounds are in a way N,S-acetals of ketenes. ... Zie: Summary

  9. 21 CFR 862.1390 - 5-Hydroxyindole acetic acid/serotonin test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false 5-Hydroxyindole acetic acid/serotonin test system. 862.1390 Section 862.1390 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Test Systems § 862.1390 5-Hydroxyindole acetic acid/serotonin test system. (a) Identification. A...

  10. 77 FR 27776 - Advisory Council for the Elimination of Tuberculosis Meeting (ACET)

    Science.gov (United States)

    2012-05-11

    ... for ACET; (2) Modeling TB Epidemiology; (3) Tuberculosis Outbreaks in Special Populations; (4) The... Tuberculosis Meeting (ACET) In accordance with section 10(a)(2) of the Federal Advisory Committee Act (Pub. L... Director, CDC, regarding the elimination of tuberculosis. Specifically, the Council makes...

  11. Thermoreversible gelation of cellulose acetate solutions studied by differential scanning calorimetry

    NARCIS (Netherlands)

    Altena, F.W.; Schroder, J.S.; Huls, van de R.; Smolders, C.A.

    1986-01-01

    Thermoreversible gels of cellulose acetate can be obtained by cooling concentrated cellulose acetate solutions in solvent-nonsolvent mixtures of dioxane and water. Upon heating the gels, endothermic effects were observed with differential scanning calorimetry. The heat effects are ascribed to the me

  12. A Phase Transfer Catalyzed Permanganate Oxidation: Preparation of Vanillin from Isoeugenol Acetate.

    Science.gov (United States)

    Lampman, Gary M.; Sharpe, Steven D.

    1983-01-01

    Background information, laboratory procedures, and results are provided for the preparation of vanillin from isoeugenol acetate. Reaction scheme used to prepare the vanillin and a table indicating the different oxidation experiments carried out on isoeugenol or isoeugenol acetate are also provided. (JN)

  13. Brain MR finding of {beta}-fluoroethyl acetate rodenticide intoxication: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Young; Jung, Cheol Kyu; Lee, Seung Ro; Park, Dong Woo [College of Medicine, Hanyang University, Seoul (Korea, Republic of)

    2008-05-15

    {beta}-fluoroethyl acetate rodenticide intoxication can manifest as several different clinical abnormalities such as respiratory, neurologic, cardiologic and fluid-electrolyte problems. We report here on the MR findings of a case that showed symmetric cytotoxic edema in the while matter of the cerebral hemispheres after the ingestion of {beta} - fluoroethyl acetate rodenticide by a woman who was attempting suicide.

  14. 21 CFR 529.1003 - Flurogestone acetate-impregnated vaginal sponge.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Flurogestone acetate-impregnated vaginal sponge... § 529.1003 Flurogestone acetate-impregnated vaginal sponge. (a) Specifications. Each vaginal sponge... ewes during their normal breeding season. (2) Limitations. Using applicator provided, insert...

  15. Investigation of acetic acid-catalyzed hydrothermal pretreatment on corn stover

    DEFF Research Database (Denmark)

    Xu, Jian; Thomsen, Mette Hedegaard; Thomsen, Anne Belinda

    2010-01-01

    Acetic acid (AA)-catalyzed liquid hot water (LHW) pretreatments on raw corn stover (RCS) were carried out at 195 °C at 15 min with the acetic acid concentrations between 0 and 400 g/kg RCS. After pretreatment, the liquor fractions and water-insoluble solids (WIS) were collected separately...

  16. Enhanced expression of aconitase raises acetic acid resistance in Acetobacter aceti.

    Science.gov (United States)

    Nakano, Shigeru; Fukaya, Masahiro; Horinouchi, Sueharu

    2004-06-15

    Acetobacter spp. are used for industrial vinegar production because of their high ability to oxidize ethanol to acetic acid and high resistance to acetic acid. Two-dimensional gel electrophoretic analysis of a soluble fraction of Acetobacter aceti revealed the presence of several proteins whose production was enhanced, to various extents, in response to acetic acid in the medium. A protein with an apparent molecular mass of 100 kDa was significantly enhanced in amount by acetic acid and identified to be aconitase by NH2-terminal amino acid sequencing and subsequent gene cloning. Amplification of the aconitase gene by use of a multicopy plasmid in A. aceti enhanced the enzymatic activity and acetic acid resistance. These results showed that aconitase is concerned with acetic acid resistance. Enhancement of the aconitase activity turned out to be practically useful for acetic acid fermentation, because the A. aceti transformant harboring multiple copies of the aconitase gene produced a higher concentration of acetic acid with a reduced growth lag-time.

  17. Cervical cancer risk factors and feasibility of visual inspection with acetic acid screening in Sudan

    DEFF Research Database (Denmark)

    Ibrahim, Ahmed; Rasch, Vibeke; Pukkala, Eero;

    2011-01-01

    To assess the risk factors of cervical cancer and the feasibility and acceptability of a visual inspection with acetic acid (VIA) screening method in a primary health center in Khartoum, Sudan.......To assess the risk factors of cervical cancer and the feasibility and acceptability of a visual inspection with acetic acid (VIA) screening method in a primary health center in Khartoum, Sudan....

  18. Acetic acid induces pH-independent cellular energy depletion in Salmonella enterica.

    Science.gov (United States)

    Tan, Sin Mei; Lee, Sui Mae; Dykes, Gary A

    2015-03-01

    Weak organic acids are widely used as preservatives and disinfectants in the food industry. Despite their widespread use, the antimicrobial mode of action of organic acids is still not fully understood. This study investigated the effect of acetic acid on the cell membranes and cellular energy generation of four Salmonella strains. Using a nucleic acid/protein assay, it was established that acetic acid did not cause leakage of intracellular components from the strains. A scanning electron microscopy study further confirmed that membrane disruption was not the antimicrobial mode of action of acetic acid. Some elongated Salmonella cells observed in the micrographs indicated a possibility that acetic acid may inhibit DNA synthesis in the bacterial cells. Using an ATP assay, it was found that at a neutral pH, acetic acid caused cellular energy depletion with an ADP/ATP ratio in the range between 0.48 and 2.63 (pacid molecules. The antimicrobial effect of acetic acid was better under acidic conditions (ADP/ATP ratio of 5.56 ± 1.27; pacid molecules can act together. We concluded that the inhibitory effect of acetic acid is not solely attributable to acidic pH but also to undissociated acid molecules. This finding has implication for the use of acetic acid as an antimicrobial against Salmonella on food products, such as chicken meat, which can buffer its pH.

  19. Efficacy of Acetic Acid against Listeria monocytogenes Attached to Poultry Skin during Refrigerated Storage.

    Science.gov (United States)

    Gonzalez-Fandos, Elena; Herrera, Barbara

    2014-09-11

    This work evaluates the effect of acetic acid dipping on the growth of L. monocytogenes on poultry legs stored at 4 °C for eight days. Fresh inoculated chicken legs were dipped into either a 1% or 2% acetic acid solution (v/v) or distilled water (control). Changes in mesophiles, psychrotrophs, Enterobacteriaceae counts and sensorial characteristics (odor, color, texture and overall appearance) were also evaluated. The shelf life of the samples washed with acetic acid was extended by at least two days over the control samples washed with distilled water. L. monocytogenes counts before decontamination were 5.57 log UFC/g, and after treatment with 2% acetic acid (Day 0), L. monocytogenes counts were 4.47 log UFC/g. Legs washed with 2% acetic acid showed a significant (p acetic acid. This study demonstrates that while acetic acid did reduce populations of L. monocytogenes on meat, it did not completely inactivate the pathogen. The application of acetic acid may be used as an additional hurdle contributing to extend the shelf life of raw poultry and reducing populations of L. monocytogenes.

  20. A Binary Host Plant Volatile Lure Combined With Acetic Acid to Monitor Codling Moth (Lepidoptera: Tortricidae).

    Science.gov (United States)

    Knight, A L; Basoalto, E; Katalin, J; El-Sayed, A M

    2015-10-01

    Field studies were conducted in the United States, Hungary, and New Zealand to evaluate the effectiveness of septa lures loaded with ethyl (E,Z)-2,4-decadienoate (pear ester) and (E)-4,8-dimethyl-1,3,7-nonatriene (nonatriene) alone and in combination with an acetic acid co-lure for both sexes of codling moth, Cydia pomonella (L.). Additional studies were conducted to evaluate these host plant volatiles and acetic acid in combination with the sex pheromone, (E,E)-8,10-dodecadien-1-ol (codlemone). Traps baited with pear ester/nonatriene + acetic acid placed within orchards treated either with codlemone dispensers or left untreated caught significantly more males, females, and total moths than similar traps baited with pear ester + acetic acid in some assays. Similarly, traps baited with codlemone/pear ester/nonatriene + acetic acid caught significantly greater numbers of moths than traps with codlemone/pear ester + acetic acid lures in some assays in orchards treated with combinational dispensers (dispensers loaded with codlemone/pear ester). These data suggest that monitoring of codling moth can be marginally improved in orchards under variable management plans using a binary host plant volatile lure in combination with codlemone and acetic acid. These results are likely to be most significant in orchards treated with combinational dispensers. Significant increases in the catch of female codling moths in traps with the binary host plant volatile blend plus acetic acid should be useful in developing more effective mass trapping strategies.

  1. Catalysis of the Carbonylation of Alcohols to Carboxylic Acids Including Acetic Acid Synthesis from Methanol.

    Science.gov (United States)

    Forster, Denis; DeKleva, Thomas W.

    1986-01-01

    Monsanto's highly successful synthesis of acetic acid from methanol and carbon monoxide illustrates use of new starting materials to replace pretroleum-derived ethylene. Outlines the fundamental aspects of the acetic acid process and suggests ways of extending the synthesis to higher carboxylic acids. (JN)

  2. [Advances in functional genomics studies underlying acetic acid tolerance of Saccharomyces cerevisiae].

    Science.gov (United States)

    Zhao, Xinqing; Zhang, Mingming; Xu, Guihong; Xu, Jianren; Bai, Fengwu

    2014-03-01

    Industrial microorganisms are subject to various stress conditions, including products and substrates inhibitions. Therefore, improvement of stress tolerance is of great importance for industrial microbial production. Acetic acid is one of the major inhibitors in the cellulosic hydrolysates, which affects seriously on cell growth and metabolism of Saccharomyces cerevisiae. Studies on the molecular mechanisms underlying adaptive response and tolerance of acetic acid of S. cerevisiae benefit breeding of robust strains of industrial yeast for more efficient production. In recent years, more insights into the molecular mechanisms underlying acetic acid tolerance have been revealed through analysis of global gene expression and metabolomics analysis, as well as phenomics analysis by single gene deletion libraries. Novel genes related to response to acetic acid and improvement of acetic acid tolerance have been identified, and novel strains with improved acetic acid tolerance were constructed by modifying key genes. Metal ions including potassium and zinc play important roles in acetic acid tolerance in S. cerevisiae, and the effect of zinc was first discovered in our previous studies on flocculating yeast. Genes involved in cell wall remodeling, membrane transport, energy metabolism, amino acid biosynthesis and transport, as well as global transcription regulation were discussed. Exploration and modification of the molecular mechanisms of yeast acetic acid tolerance will be done further on levels such as post-translational modifications and synthetic biology and engineering; and the knowledge obtained will pave the way for breeding robust strains for more efficient bioconversion of cellulosic materials to produce biofuels and bio-based chemicals.

  3. Microbiological preservation of cucumbers for bulk storage by the use of acetic acid and food preservatives

    Science.gov (United States)

    Microbial growth did not occur when cucumbers were preserved without a thermal process by storage in solutions containing acetic acid, sodium benzoate, and calcium chloride to maintain tissue firmness. The concentrations of acetic acid and sodium benzoate required to assure preservation were low en...

  4. Comparison of polycarbonate and cellulose acetate membrane filters for isolation of Campylobacter concisus from stool samples

    DEFF Research Database (Denmark)

    Linde Nielsen, Hans; Engberg, Jørgen; Ejlertsen, Tove;

    2013-01-01

    One thousand seven hundred ninety-one diarrheic stool samples were cultivated for Campylobacter spp. We found a high prevalence of Campylobacter concisus with use of a polycarbonate filter (n = 114) compared to a cellulose acetate filter (n = 79) (P ... to the commonly used cellulose acetate filter for detection of C. concisus....

  5. Palladium-catalyzed cross-coupling reactions of allylic halides and acetates with indium organometallics.

    Science.gov (United States)

    Rodríguez, David; Pérez Sestelo, José; Sarandeses, Luis A

    2004-11-12

    The palladium(0)-catalyzed cross-coupling reaction of allylic halides and acetates with indium organometallics is reported. In this synthetic transformation, triorganoindium compounds and tetraorganoindates (aryl, alkenyl, and methyl) react with cinnamyl and geranyl halides and acetates to afford the S(N)2 product regioselectively and in good yield. The reaction proceeds with net inversion of the stereochemical configuration.

  6. [Conversion of acetic acid to methane by thermophiles]. Annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Zinder, S.H.

    1994-02-01

    Acetate is the precursor of approximately two-thirds of the methane produced by anaerobic bioreactors and many other methanogenic habitats. Besides their intrinsic interest, thermophilic acetotrophic methanogenic cultures usually grow at least twice as fast as their mesophilic counterparts, making them more amenable to study. In recent years, attention has been mainly focused on the thermophilic acetate utilizing methanogen Methanothrix strain CALS-1. Methanothrix, also called Methanosaeta, is one of only two methanogenic genera known to convert acetate to methane, the other being Methanosarcina. The faster-growing more versatile Methanosarcina has been better studied. However, when one examines anaerobic digestor contents, Methanothrix is often the dominant acetate-utilizing methanogen. As described in previous progress reports, the authors have achieved methanogenesis from acetate in cell-free extracts of Methanothrix strain CALS-1 grown in a pH auxostat. Using these cell extracts, specific activities for methanogenesis from acetate and ATP of 100--300 nmol/min were routinely obtained, levels comparable to the rate in whole cells, which is not usually the case in methanogenic extracts. Recently obtained results are given and discussed for the following: Methanogenesis in crude extracts; Role of the cell membrane in methanogenesis from acetate; Carbon monoxide dehydrogenase; Novel thermophilic cultures converting acetate to methane; and Methanol-utilizing methanogen.

  7. Effect of acetate on lead toxicity to microbial biomass in a red soil

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    A laboratory incubation experiment was conducted to elucidate the effect of acetate on lead bioavailability and toxicity to microbial biomass in a red soil. Treatment included the application of lead at six different levels i.e., 0(background), 100, 200, 300, 450 and 600μg/g soil with three levels of the acetate(0, 900 and 2700 μg/g soil). Results indicated that the application of acetate along or at the lower lead levels of 100 and 200μg/g soil stimulated the soil microbial biomass. The addition of acetate at the higher lead levels of 300, 450 and 600 μg/g soil caused significantly greater reductions in the biomass carbon(Cmic) and the biomass nitrogen(Nmic), compared with the control or the same lead levels applied individually. A greater increase in the biomass C:N ratio occurred by acetate addition at the same lead levels. The concentration of 0.01mol/L CaCl2-extractable lead was considerably higher in the lead plus acetate treatments than at the same lead levels with no acetate.Based on these results, it was concluded that the application of acetate might have suppressed the lead adsorption in the soil which in turn resulted in its more bioavailability and hence more toxicity to the soil microbial biomass.

  8. 42 CFR 84.1142 - Isoamyl acetate tightness test; respirators designed for respiratory protection against dusts...

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Isoamyl acetate tightness test; respirators... Mist; Pesticide; Paint Spray; Powered Air-Purifying High Efficiency Respirators and Combination Gas Masks § 84.1142 Isoamyl acetate tightness test; respirators designed for respiratory protection...

  9. The Vinyl Acetate Content of Packaging Film: A Quantitative Infrared Experiment.

    Science.gov (United States)

    Allpress, K. N.; And Others

    1981-01-01

    Presents an experiment used in laboratory technician training courses to illustrate the quantitative use of infrared spectroscopy which is based on industrial and laboratory procedures for the determination of vinyl acetate levels in ethylene vinyl acetate packaging films. Includes three approaches to allow for varying path lengths (film…

  10. The amrG1 gene is involved in the activation of acetate in Corynebacterium glutamicum

    Institute of Scientific and Technical Information of China (English)

    RUAN; Hong; R.; Gerstmeir; S.; Schnicke; B.J.; Eikmanns

    2005-01-01

    During growth of Corynebacterium glutamicum on acetate as its carbon and energy source, the expression of the pta-ack operon is induced, coding for the acetate-activating enzymes, which are phosphotransacetylase (PTA) and acetate kinase (AK). By transposon rescue, we identified the two genes amrG1 and amrG2 found in the deregulated transposon mutant C. glutamicum G25. The amrG1 gene (NCBI-accession: AF532964) has a size of 732 bp, encoding a polypeptide of 243 amino acids and apparently is partially responsible for the regulation of acetate metabolism in C. glutamicum. We constructed an in-frame deletion mutant and an overexpressing strain of amrG1 in the C. glutamicum ATCC13032 wildtype. The strains were then analyzed with respect to their enzyme activities of PTA and AK during growth on glucose, acetate and glucose or acetate alone as carbon sources. Compared to the parental strain, the amrG1 deletion mutant showed higher specific AK and PTA activities during growth on glucose but showed the same high specific activities of AK and PTA on medium containing acetate plus glucose and on medium containing acetate. In contrast to the gene deletion, overexpression of the amrG1 gene in C. glutamicum 13032 had the adverse regulatory effect. These results indicate that the amrG1 gene encodes a repressor or co-repressor of the pta-ack operon.

  11. Zymomonas with improved ethanol production in medium containing concentrated sugars and acetate

    Science.gov (United States)

    Caimi, Perry G.; Chou, Yat-Chen; Franden, Mary Ann; Knoke, Kyle; Tao, Luan; Viitanen, Paul V.; Zhang, Min; Zhang, Yuying

    2010-09-28

    Through screening of a Zymomonas mutant library the himA gene was found to be involved in the inhibitory effect of acetate on Zymomonas performance. Xylose-utilizing Zymomonas further engineered to reduce activity of the himA gene were found to have increased ethanol production in comparison to a parental strain, when cultured in medium comprising xylose and acetate.

  12. Fabrication of First Chinese Made Reactor for Oxosvnthesis of Acetic Acid in Xi'an

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The first set of Chinese made reactor for oxo-synthesis of acetic acid has been fabricated by the Xi'an Nuclear Equipment Company,Ltd.This reactor has been transported to the site of equipment installation at the acetic acid production project owned by Shandong Yimeng Company,Ltd.,which has shattered the long-time precedent of relying upon imported equipment.

  13. Norethisterone acetate in combination with estrogen: effects on the skeleton and other organs. A review.

    Science.gov (United States)

    Riis, Bente Juel; Lehmann, Hans-Jørgen; Christiansen, Claus

    2002-10-01

    This article is focused on the use of norethisterone acetate as progestogen in hormone replacement therapy. Emphasis is made on the fact that the primary reason for adding a progestogen to hormone replacement therapy is to protect the endometrium against hyperplasia. In this paper we review data that demonstrate that hormone replacement therapy that includes norethisterone acetate has positive effects on the postmenopausal bone metabolism and that it increases bone mass more than expected and more than treatment with alendronate. All available evidence is reviewed to show that norethisterone acetate, if given in the correct dosage, does not influence serum lipids and lipoproteins in any negative way. It is furthermore shown that norethisterone acetate seems to be superior compared to other progestogens to provide optimum bleeding control and endometrial protection. Also, hormone replacement therapy combinations with norethisterone acetate efficiently alleviate hot flushes. Hormone replacement therapy and the risk of breast cancer and the role of progestogens are discussed.

  14. Effect of roxatidine acetate on daytime and night-time peptone-stimulated gastric acid secretion.

    Science.gov (United States)

    Hagenmüller, F

    1988-01-01

    A double-blind, randomised, crossover study in 12 healthy volunteers was performed to assess the effects of roxatidine acetate 75 mg or placebo administered at 8 am and 9 pm on peptone-stimulated hydrochloric acid secretion. In comparison to placebo, roxatidine acetate produced an average reduction of daytime hydrochloric acid output of 86% and 32%, respectively, for the 4- to 6-hour and 10- to 12-hour post-drug administration phases. In addition, roxatidine acetate produced reductions in nocturnal hydrochloric acid output of 75 to 92% with an associated rise in intragastric pH of around 2 units compared to placebo. No side effects or clinically significant alterations in haematological or biochemical values were reported following roxatidine acetate administration. These results suggest that roxatidine acetate is a potent and effective inhibitor of day and night-time intragastric acid secretion.

  15. Atmospheric geochemistry of formic and acetic acids at a mid-latitude temperate site

    Science.gov (United States)

    Talbot, R. W.; Beecher, K. M.; Harriss, R. C.; Cofer, R. W., III

    1988-01-01

    Tropospheric concentrations of formic and acetic acids in the gas, the aerosol, and the rainwater phases were determined in samples collected 1-2 m above ground level at an open field site in eastern Virginia. These acids were found to occur principally (98 percent or above) in the gas phase, with a marked annual seasonality, averaging 1890 ppt for formate and 1310 ppt for acetate during the growing season, as compared to 695 ppt and 700 ppt, respectively, over the nongrowing season. The data support the hypothesis that biogenic emissions from vegatation are important sources of atmospheric formic and acetic acid during the local growing season. The same time trends were observed for precipitation, although with less defined seasonality. The relative increase of the acetic acid/formic acid ratio during the nongrowing season points to the dominance of anthropogenic inputs of acetic acid from motor vehicles and biomass combustion in the wintertime.

  16. Development of Acetic Acid Removal Technology for the UREX+Process

    Energy Technology Data Exchange (ETDEWEB)

    Robert M. Counce; Jack S. Watson

    2009-06-30

    It is imperative that acetic acid is removed from a waste stream in the UREX+process so that nitric acid can be recycled and possible interference with downstreatm steps can be avoidec. Acetic acid arises from acetohydrozamic acid (AHA), and is used to suppress plutonium in the first step of the UREX+process. Later, it is hydrolyzed into hydroxyl amine nitrate and acetic acid. Many common separation technologies were examined, and solvent extraction was determined to be the best choice under process conditions. Solvents already used in the UREX+ process were then tested to determine if they would be sufficient for the removal of acetic acid. The tributyl phosphage (TBP)-dodecane diluent, used in both UREX and NPEX, was determined to be a solvent system that gave sufficient distribution coefficients for acetic acid in addition to a high separation factor from nitric acid.

  17. Cell wall dynamics modulate acetic acid-induced apoptotic cell death of Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    António Rego

    2014-08-01

    Full Text Available Acetic acid triggers apoptotic cell death in Saccharomyces cerevisiae, similar to mammalian apoptosis. To uncover novel regulators of this process, we analyzed whether impairing MAPK signaling affected acetic acid-induced apoptosis and found the mating-pheromone response and, especially, the cell wall integrity pathways were the major mediators, especially the latter, which we characterized further. Screening downstream effectors of this pathway, namely targets of the transcription factor Rlm1p, highlighted decreased cell wall remodeling as particularly important for acetic acid resistance. Modulation of cell surface dynamics therefore emerges as a powerful strategy to increase acetic acid resistance, with potential application in industrial fermentations using yeast, and in biomedicine to exploit the higher sensitivity of colorectal carcinoma cells to apoptosis induced by acetate produced by intestinal propionibacteria.

  18. Synthesis and Characterization of Cellulose Acetate from TCF Oil Palm Empty Fruit Bunch Pulp

    Directory of Open Access Journals (Sweden)

    Fauzi Muhammad Djuned

    2014-06-01

    Full Text Available Cellulose acetate (CA was successfully synthesized by the acetylation of TCF cellulose pulp from oil palm empty fruit bunches (OPEFB at room temperature, using acetic anhydride as the acetylating agent and acetic acid as the solvent in the presence of sulfuric acid/sodium bisulfate as catalysts. Degree of substitution (DS was controlled by the variables of acetylation time and acetic anhydride to cellulose ratio, under the heterogeneous state. The product (CA obtained was characterized through Fourier transform infrared spectroscopy (FTIR, nuclear magnetic resonance spectroscopy (NMR, differential scanning calorimetry (DSC, X-ray diffraction (XRD, and scanning electron microscopy (SEM. The results indicate that the CA obtained has characteristics similar to commercial CA, and DS is significantly dependent on acetylation time and the acetic anhydride-to-cellulose ratio.

  19. Progress in Acetic Acid Industry%醋酸工业现状及发展

    Institute of Scientific and Technical Information of China (English)

    李好管; 闫慧芳

    2001-01-01

    醋酸是用途最广泛的有机酸之一。分析了醋酸的生产和消费趋势;综述了醋酸工艺的进展;介绍了具有工业化前景或学术价值的醋酸合成新工艺的研究开发概况。对我国醋酸工业发展提出了建议。%Acetic acid is one of the organic acids which have many uses.This paper analyzed the production and consumption of acetic acid,summarized the progress of acetic acid technology,introduced the research and development of acetic acid new process.Some suggestions on China's acetic acid industry were also put forward.

  20. Recovery of Dilute Acetic Acid by Catalytic Distillation Using NKC-9 as Catalyst

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhigang; LI Xiaofeng; XU Shimin; LI Xingang

    2006-01-01

    The reaction kinetics of dilute acetic acid with methanol using NKC-9 as catalyst was studied at temperatures of 308 K, 318 K, 323 K, 328 K. The kinetic model based on Langmuir-Hinshelwood rate model was derived and the activation energy was 6.13 x 104 kJ/kmol. The experiment of recovery of dilute acetic acid was conducted in a packed bed catalytic distillation column. The optimal process parameters and operational conditions determined to make up to 85.9% conversion of acetic acid are as follows:the height of catalyst bed is 1 100 mm, reflux ratio is 4: 1, and the ratio of methanol to acetic acid is 2: 1. The method can be used as a guide in industrial scale recovery of 15%-30% dilute acetic acid.

  1. C-13 Stable Isotope Probing of Biostimulation Experiments to Identify Acetate Utilizers

    Science.gov (United States)

    Jaffe, P. R.; Tan, H.; Kerkhof, L.; McGuinness, L.; Peacock, A.; Long, P. E.

    2011-12-01

    In order to determine which microorganisms take up acetate during biostimulation and how the uptake of acetate by specific organisms, especially Geobacter species, changes over time, a 120-day column biostimulation experiment was performed. A total of eight columns were loaded with Rifle sediments and operated under continuous flow conditions using Rifle groundwater, amended with 3 mM C-12 acetate. At regular time intervals, C-12 acetate flow into a specific column was switched to C-13 acetate. That column was then operated under C-13 acetate amendment for 36 hours before it was sacrificed for detailed geochemical and microbiological analyses. Column operation started under iron reduction (based on the measured Fe(II) in the column effluent), while sulfate reduction (based on removal of sulfate between influent and outflow), was noted at about 25 days of operation. The microbial characterization consisted of phospholipid fatty acid analysis (PLFA) and stable isotope probing (SIP). All microbial characterization was done to differentiate between the C-12 and C-13 incorporation into the biomass. Results showed that there was a differentiation between the community that was taking up acetate actively throughout the 120 days of operation and the overall microbial community. Of interest was that the fraction of Geobacter population remained fairly constant throughout the duration of the experiment, as well as its acetate uptake. Results also showed that of the acetate incorporated into the overall biomass, about 40% was incorporated into Geobacter biomass. These results are key for the proper numerical simulations of biostimulation via acetate amendment and the biostimulation of Geobacter.

  2. Isolation, characterization and optimization of indigenous acetic acid bacteria and evaluation of their preservation methods

    Directory of Open Access Journals (Sweden)

    K Beheshti-Maal

    2010-06-01

    Full Text Available Background and Objectives: Acetic acid bacteria (AAB are useful in industrial production of vinegar. The present study aims at isolation and identification of acetic acid bacteria with characterization, optimization, and evaluation of their acetic acid productivity."nMaterials and Methods: Samples from various fruits were screened for presence of acetic acid bacteria on glucose, yeast extract, calcium carbonate (GYC medium. Carr medium supplemented with bromocresol green was used for distinguishing Acetobacter from Gluconobacter. The isolates were cultured in basal medium to find the highest acetic acid producer. Biochemical tests followed by 16S rRNA and restriction analyses were employed for identification of the isolate and phylogenic tree was constructed. Bacterial growth and acid production conditions were optimized based on optimal inoculum size, pH, temperature, agitation, aeration and medium composition."nResults: Thirty-seven acetic acid bacteria from acetobacter and gluconobacter members were isolated. Acetic acid productivity yielded 4 isolates that produced higher amounts of acid. The highest producer of acid (10.03% was selected for identification. The sequencing and restriction analyses of 16S rRNA revealed a divergent strain of Acetobacter pasteurianus (Gene bank accession number # GU059865. The optimum condition for acid production was a medium composed of 2% glucose, 2% yeast extract, 3% ethanol and 3% acid acetic at inoculum size of 4% at 3L/Min aeration level in the production medium. The isolate was best preserved in GYC medium at 12oC for more than a month. Longer preservation was possible at -70oC."nConclusion: The results are suggestive of isolation of an indigenous acetic acid bacteria. Pilot plan is suggested to study applicability of the isolated strain in acetic acid production.

  3. Acute Alcohol Intoxication Decreases Glucose Metabolism but Increases Acetate Uptake in the Human Brain

    Science.gov (United States)

    Volkow, Nora D.; Kim, Sung Won; Wang, Gene-Jack; Alexoff, David; Logan, Jean; Muench, Lisa; Shea, Colleen; Telang, Frank; Fowler, Joanna S.; Wong, Christopher; Benveniste, Helene; Tomasi, Dardo

    2012-01-01

    Alcohol intoxication results in marked reductions in brain glucose metabolism, which we hypothesized reflect not just its GABAergic enhancing effects but also metabolism of acetate as an alternative brain energy source. To test this hypothesis we separately assessed the effects of alcohol intoxication on brain glucose and acetate metabolism using Positron Emission Tomography (PET). We found that alcohol intoxication significantly decreased whole brain glucose metabolism (measured with FDG) with the largest decrements in cerebellum and occipital cortex and the smallest in thalamus. In contrast, alcohol intoxication caused a significant increase in [1-11C]acetate brain uptake (measured as standard uptake value, SUV), with the largest increases occurring in cerebellum and the smallest in thalamus. In heavy alcohol drinkers [1-11C]acetate brain uptake during alcohol challenge trended to be higher than in occasional drinkers (p <0.06) and the increases in [1-11C]acetate uptake in cerebellum with alcohol were positively associated with the reported amount of alcohol consumed (r=0.66, p<0.01). Our findings corroborate a reduction of brain glucose metabolism during intoxication and document an increase in brain acetate uptake. The opposite changes observed between regional brain metabolic decrements and regional increases in [1-11C]acetate uptake support the hypothesis that during alcohol intoxication the brain may rely on acetate as an alternative brain energy source and provides preliminary evidence that heavy alcohol exposures may facilitate the use of acetate as an energy substrate. These findings raise the question of the potential therapeutic benefits that increasing plasma acetate concentration (ie ketogenic diets) may have in alcoholics undergoing alcohol detoxification. PMID:22947541

  4. Evaluation of the morphological changes of gastric mucosa induced by a low concentration of acetic acid using a rat model.

    Science.gov (United States)

    Nakao, Ken-ichiro; Ro, Ayako; Kibayashi, Kazuhiko

    2014-02-01

    Oral ingestion of concentrated acetic acid causes corrosive injury of the gastrointestinal tract. To assess the effects of a low concentration of acetic acid on gastric mucosa, we examined the gastric mucosal changes in rats at 1 and 3 days after the injection of 5% or 25% acetic acid into the gastric lumen. The area of the gastric ulcerative lesions in the 25% acetic acid group was significantly larger than that in the 5% acetic acid group. The lesion area was reduced significantly at 3 days after injection in the 5% acetic acid group, whereas no significant difference in lesion area was observed at 1 and 3 days in the 25% acetic acid group. Histologically, corrosive necrosis was limited to the mucosal layer in the 5% acetic acid group, whereas necrosis extended throughout the gastric wall in the 25% acetic acid group. At 3 days post-injection, the 25% acetic acid group showed widespread persistent inflammation, whereas the 5% acetic acid group showed widespread appearance of fibroblasts indicative of a healing process. These results indicate that a low concentration of acetic acid damages the gastric mucosa and that the degree of mucosal damage depends on the concentration of acetic acid.

  5. Metabolic regulation of the plant hormone indole-3-acetic acid

    Energy Technology Data Exchange (ETDEWEB)

    Jerry D. Cohen

    2009-11-01

    The phytohormone indole-3-acetic acid (IAA, auxin) is important for many aspects of plant growth, development and responses to the environment yet the routes to is biosynthesis and mechanisms for regulation of IAA levels remain important research questions. A critical issue concerning the biosynthesis if IAA in plants is that redundant pathways for IAA biosynthesis exist in plants. We showed that these redundant pathways and their relative contribution to net IAA production are under both developmental and environmental control. We worked on three fundamental problems related to how plants get their IAA: 1) An in vitro biochemical approach was used to define the tryptophan dependent pathway to IAA using maize endosperm, where relatively large amounts of IAA are produced over a short developmental period. Both a stable isotope dilution and a protein MS approach were used to identify intermediates and enzymes in the reactions. 2) We developed an in vitro system for analysis of tryptophan-independent IAA biosynthesis in maize seedlings and we used a metabolite profiling approach to isolate intermediates in this reaction. 3) Arabidopsis contains a small family of genes that encode potential indolepyruvate decarboxylase enzymes. We cloned these genes and studied plants that are mutant in these genes and that over-express each member in the family in terms of the level and route of IAA biosynthesis. Together, these allowed further development of a comprehensive picture of the pathways and regulatory components that are involved in IAA homeostasis in higher plants.

  6. Enantioselective Organocatalytic Cascade Approach to Different Classes of Benzofused Acetals.

    Science.gov (United States)

    Paz, Bruno Matos; Klier, Lydia; Naesborg, Line; Lauridsen, Vibeke Henriette; Jensen, Frank; Jørgensen, Karl Anker

    2016-11-14

    A novel enantioselective organocatalytic strategy is presented for the synthesis of tetrahydrofurobenzofuran and methanobenzodioxepine natural product core structures. The strategy is based on a pair of divergent reaction pathways in which hydroxyarenes react with γ-keto-α,β-unsaturated aldehydes, catalyzed by a chiral secondary amine. One reaction pathway, which leads to chiral 5,5-fused acetals with two stereocenters-the tetrahydrofurobenzofuran scaffolds-proceeds in moderate yields and up to 96 % ee. The other reaction pathway provides 5,6-bridged methanobenzodioxepine scaffolds with three stereocenters in moderate to good yields and up to 95 % ee. The reaction is remarkable as it can proceed with catalyst loadings as low as 0.25 mol %, providing one of the highest known turnover numbers in iminium ion catalysis. Furthermore, the hemiacetal tetrahydrofurobenzofuran can undergo functionalizations including reduction, oxidation, and allylation. Finally, the effects involved in the substrate control for the divergent pathways, based on both experimental and computational studies, have been investigated. A model involving steric, electronic and stereoelectronic interactions is discussed to rationalize the observed selectivities.

  7. Successful Pregnancy after Treatment with Ulipristal Acetate for Uterine Fibroids

    Directory of Open Access Journals (Sweden)

    Javier Monleón

    2014-01-01

    Full Text Available This case report presents a clinical pregnancy after ulipristal acetate (UA to decrease uterine fibroid size. A 37-year-old patient, gravida 1, abortus 1, with uterine fibroids was treated with 5 mg of UA daily for 13 weeks starting eight months after a multiple laparotomic myomectomy. Fibroid shrinkage and restoration of the morphology of endometrial cavity were evaluated in order to allow a subsequent pregnancy. A decrease of the uterine fibroids and a normal morphology of the endometrial cavity were noted by transvaginal ultrasound after treatment. An endometrial biopsy excluded histologic endometrial changes. Three months after the end of UA the patient reported amenorrhea for 5 weeks and a clinical pregnancy was confirmed with transvaginal ultrasound. She underwent a subsequent uneventful pregnancy. Thus, the spontaneous pregnancy after UA to reduce fibroid size may support the potential clinical utility of this selective progesterone receptor modulator in the management of women with pregnancy desire and uterine fibroids after a prior myomectomy. Patients who refuse a new surgical procedure and/or those who are going to undergo assisted reproductive techniques would benefit from UA. It effectively shrinks fibroids, avoids risks of a new surgical procedure, and allows an immediate attempt at conception after the end of treatment.

  8. Successful pregnancy after treatment with ulipristal acetate for uterine fibroids.

    Science.gov (United States)

    Monleón, Javier; Martínez-Varea, Alicia; Galliano, Daniela; Pellicer, Antonio

    2014-01-01

    This case report presents a clinical pregnancy after ulipristal acetate (UA) to decrease uterine fibroid size. A 37-year-old patient, gravida 1, abortus 1, with uterine fibroids was treated with 5 mg of UA daily for 13 weeks starting eight months after a multiple laparotomic myomectomy. Fibroid shrinkage and restoration of the morphology of endometrial cavity were evaluated in order to allow a subsequent pregnancy. A decrease of the uterine fibroids and a normal morphology of the endometrial cavity were noted by transvaginal ultrasound after treatment. An endometrial biopsy excluded histologic endometrial changes. Three months after the end of UA the patient reported amenorrhea for 5 weeks and a clinical pregnancy was confirmed with transvaginal ultrasound. She underwent a subsequent uneventful pregnancy. Thus, the spontaneous pregnancy after UA to reduce fibroid size may support the potential clinical utility of this selective progesterone receptor modulator in the management of women with pregnancy desire and uterine fibroids after a prior myomectomy. Patients who refuse a new surgical procedure and/or those who are going to undergo assisted reproductive techniques would benefit from UA. It effectively shrinks fibroids, avoids risks of a new surgical procedure, and allows an immediate attempt at conception after the end of treatment.

  9. Sodium Acetate Stimulates PHB Biosynthesis in Synechocystis sp. PCC 6803

    Institute of Scientific and Technical Information of China (English)

    吴桂芳; 鲍恬; 沈忠耀; 吴庆余

    2002-01-01

    Synechocystis sp. PCC 6803 cell growth and poly-β-hydroxybutyrate (PHB) biosynthesis were studied in the presence of sodium acetate (NaAc). For nitrogen-sufficient conditions, 15 -mmol/L NaAc improved the PHB content up to 9.9% (w/w) while for nitrogen-starved conditions, the PHB content was up to 15.2% (w/w). NaAc at levels below 20 -mmol/L promoted cell growth in the first six days, but the growth slowed on the seventh day when the NaAc concentration exceeded 15 -mmol/L. The PHB content in the final biomass reached 11.0% of the dry cellular weight in the presence of 20 -mmol/L NaAc. Two adjacent open reading frames (ORFs) in the genome of Synechocystis sp. PCC 6803, slr1993 and slr1994, were assigned to phbA and phbB, respectively, while the phbC gene was found to be far from these genes. This may account for the low expression of PHB in cyanobacteria.

  10. Hepatotoxicity induced by cyproterone acetate: A report of three cases

    Institute of Scientific and Technical Information of China (English)

    Ioanna Savidou; Melanie Deutsch; Aspasia S Soultati; Dimitrios Koudouras; Georgia Kafiri; Spyridon P Dourakis

    2006-01-01

    Cyproterone acetate (CPA) is a steroidal synthetic progestagen and anti-androgenic compound widely administered in prostate cancer which has been evidentially correlated with a severe hepatotoxic potency.Three male patients aged 78-83 years are presented, in whom severe hepatotoxic reactions emerged after CPA administration. Patients were treated with CPA at the doses of 200-300 mg/d for malignant prostate disease for 3-12 mo prior to the acute manifestation of the hepatic disease. Clinical features compatible with mixed hepatocellular and cholestatic liver disease including jaundice, white stools and dark urine, manifested in all three cases whereas encephalopathy and ascites were present in two of the patients. Other primary causes of hepatotoxicity (alcohol consumption and viral hepatitis)were also verified in two cases, and in those patients biopsy findings revealed the presence of cirrhotic lesions in liver parenchyma. Discontinuation of the therapeutic agent led to the amelioration of the clinical profile in all the patients whereas a patient died 40 d after hospital admission due to sepsis, despite acute liver disease improvement. The current article highlights the hepatotoxic potency of a widely administered therapeutic agent and illustrates the importance of clinical surveillance especially in patients with previous hepatic diseases. Three relevant cases are reported and a review of the published literature is made.

  11. Antimicrobial Lemongrass Essential Oil—Copper Ferrite Cellulose Acetate Nanocapsules

    Directory of Open Access Journals (Sweden)

    Ioannis L. Liakos

    2016-04-01

    Full Text Available Cellulose acetate (CA nanoparticles were combined with two antimicrobial agents, namely lemongrass (LG essential oil and Cu-ferrite nanoparticles. The preparation method of CA nanocapsules (NCs, with the two antimicrobial agents, was based on the nanoprecipitation method using the solvent/anti-solvent technique. Several physical and chemical analyses were performed to characterize the resulting NCs and to study their formation mechanism. The size of the combined antimicrobial NCs was found to be ca. 220 nm. The presence of Cu-ferrites enhanced the attachment of LG essential oil into the CA matrix. The magnetic properties of the combined construct were weak, due to the shielding of Cu-ferrites from the polymeric matrix, making them available for drug delivery applications where spontaneous magnetization effects should be avoided. The antimicrobial properties of the NCs were significantly enhanced with respect to CA/LG only. This work opens novel routes for the development of organic/inorganic nanoparticles with exceptional antimicrobial activities.

  12. Stratification of Hepatocellular Carcinoma Patients Based on Acetate Utilization

    Directory of Open Access Journals (Sweden)

    Elias Björnson

    2015-12-01

    Full Text Available Hepatocellular carcinoma (HCC is a deadly form of liver cancer that is increasingly prevalent. We analyzed global gene expression profiling of 361 HCC tumors and 49 adjacent noncancerous liver samples by means of combinatorial network-based analysis. We investigated the correlation between transcriptome and proteome of HCC and reconstructed a functional genome-scale metabolic model (GEM for HCC. We identified fundamental metabolic processes required for cell proliferation using the network centric view provided by the GEM. Our analysis revealed tight regulation of fatty acid biosynthesis (FAB and highly significant deregulation of fatty acid oxidation in HCC. We predicted mitochondrial acetate as an emerging substrate for FAB through upregulation of mitochondrial acetyl-CoA synthetase (ACSS1 in HCC. We analyzed heterogeneous expression of ACSS1 and ACSS2 between HCC patients stratified by high and low ACSS1 and ACSS2 expression and revealed that ACSS1 is associated with tumor growth and malignancy under hypoxic conditions in human HCC.

  13. Effect of doping on TSD relaxation in cellulose acetate films

    Indian Academy of Sciences (India)

    P K Khare; P L Jain; R K Pandey

    2000-12-01

    Thermally stimulated depolarization current (TSDC) studies have been performed on solution grown cellulose acetate films doped with different concentrations of acrylic acid (AA) prepared at the poling temperatures (40–75°C) with poling fields (10–50 kV/cm). The TSDC spectra of pure and AA doped CA films reveal two relaxation peaks at 80°C and 180 ± 2°C, having activation energies centred around 0.25 and 0.55 eV. The phenomena of the existence of these current maxima have been analyzed and discussed in terms of the molecular motion of the polar side groups and release of the remaining part of the frozen dipoles by their cooperative motion with adjoining segments of the main polymer chain. The peak currents, released charge and activation energies associated with the peaks are affected by AA doping. The effect of doping with acrylic acid on the discharge current indicates the formation of molecular aggregates.

  14. Thermal Conductivity of Ethylene Vinyl Acetate Copolymer/Nanofiller Blends

    Science.gov (United States)

    Ghose, S.; Watson, K. A.; Working, D. C.; Connell, J. W.; Smith, J. G., Jr.; Lin, Y.; Sun, Y. P.

    2007-01-01

    To reduce weight and increase the mobility, comfort, and performance of future spacesuits, flexible, thermally conductive fabrics and plastic tubes are needed for the Liquid Cooling and Ventilation Garment. Such improvements would allow astronauts to operate more efficiently and safely for extended extravehicular activities. As an approach to raise the thermal conductivity (TC) of an ethylene vinyl acetate copolymer (Elvax 260), it was compounded with three types of carbon based nanofillers: multi-walled carbon nanotubes (MWCNTs), vapor grown carbon nanofibers (CNFs), and expanded graphite (EG). In addition, other nanofillers including metallized CNFs, nickel nanostrands, boron nitride, and powdered aluminum were also compounded with Elvax 260 in the melt at various loading levels. In an attempt to improve compatibility between Elvax 260 and the nanofillers, MWCNTs and EG were modified by surface coating and through noncovalent and covalent attachment of organic molecules containing alkyl groups. Ribbons of the nanocomposites were extruded to form samples in which the nanofillers were aligned in the direction of flow. Samples were also fabricated by compression molding to yield nanocomposites in which the nanofillers were randomly oriented. Mechanical properties of the aligned samples were determined by tensile testing while the degree of dispersion and alignment of nanoparticles were investigated using high-resolution scanning electron microscopy. TC measurements were performed using a laser flash (Nanoflash ) technique. TC of the samples was measured in the direction of, and perpendicular to, the alignment direction. Additionally, tubing was also extruded from select nanocomposite compositions and the TC and mechanical flexibility measured.

  15. Incensole acetate: a novel neuroprotective agent isolated from Boswellia carterii.

    Science.gov (United States)

    Moussaieff, Arieh; Shein, Na'ama A; Tsenter, Jeanna; Grigoriadis, Savvas; Simeonidou, Constantina; Alexandrovich, Alexander G; Trembovler, Victoria; Ben-Neriah, Yinon; Schmitz, Michael L; Fiebich, Bernd L; Munoz, Eduardo; Mechoulam, Raphael; Shohami, Esther

    2008-07-01

    Boswellia resin has been used as a major anti-inflammatory agent and for the healing of wounds for centuries. Incensole acetate (IA), isolated from this resin, was shown to inhibit the activation of nuclear factor-kappaB, a key transcription factor in the inflammatory response. We now show that IA inhibits the production of inflammatory mediators in an in vitro model system of C6 glioma and human peripheral monocytes. Given the involvement of postinjury inflammation in the pathophysiology and outcome of traumatic brain injury, we examined the effect of IA on the inflammatory process and on the recovery of neurobehavioral and cognitive functions in a mouse model of closed head injury (CHI). In the brains of post-CHI mice, IA reduced glial activation, inhibited the expression of interleukin-1beta, and tumor necrosis factor-alpha mRNAs, and induced cell death in macrophages at the area of trauma. A mild hypothermic effect was also noted. Subsequently, IA inhibited hippocampal neurodegeneration and exerted a beneficial effect on functional outcome after CHI, indicated by reduced neurological severity scores and improved cognitive ability in an object recognition test. This study attributes the anti-inflammatory activity of Boswellia resin to IA and related cembranoid diterpenes and suggests that they may serve as novel neuroprotective agents.

  16. Scaleable production and separation of fermentation-derived acetic acid. Final CRADA report.

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, S. W.; Energy Systems

    2010-02-08

    Half of U.S. acetic acid production is used in manufacturing vinyl acetate monomer (VAM) and is economical only in very large production plants. Nearly 80% of the VAM is produced by methanol carbonylation, which requires high temperatures and exotic construction materials and is energy intensive. Fermentation-derived acetic acid production allows for small-scale production at low temperatures, significantly reducing the energy requirement of the process. The goal of the project is to develop a scaleable production and separation process for fermentation-derived acetic acid. Synthesis gas (syngas) will be fermented to acetic acid, and the fermentation broth will be continuously neutralized with ammonia. The acetic acid product will be recovered from the ammonium acid broth using vapor-based membrane separation technology. The process is summarized in Figure 1. The two technical challenges to success are selecting and developing (1) microbial strains that efficiently ferment syngas to acetic acid in high salt environments and (2) membranes that efficiently separate ammonia from the acetic acid/water mixture and are stable at high enough temperature to facilitate high thermal cracking of the ammonium acetate salt. Fermentation - Microbial strains were procured from a variety of public culture collections (Table 1). Strains were incubated and grown in the presence of the ammonium acetate product and the fastest growing cultures were selected and incubated at higher product concentrations. An example of the performance of a selected culture is shown in Figure 2. Separations - Several membranes were considered. Testing was performed on a new product line produced by Sulzer Chemtech (Germany). These are tubular ceramic membranes with weak acid functionality (see Figure 3). The following results were observed: (1) The membranes were relatively fragile in a laboratory setting; (2) Thermally stable {at} 130 C in hot organic acids; (3) Acetic acid rejection > 99%; and (4

  17. Commercial Application of the CTV-IV Type Catalyst for Synthesis of Vinyl Acetate Developed by Shanghai Petrochemical Research Instit

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The CTV-IV type catalyst for synthesis of vinyl acetate developed by the SINOPEC Shanghai Petrochemical Research Institute (SPRI) has been successfully applied on the #2 vinyl acetate unit at SINOPEC's Shanghai Petrochemical Company.

  18. Extraction and sorption of acetic acid at pH above pK{sub a} to form calcium magnesium acetate

    Energy Technology Data Exchange (ETDEWEB)

    Reisinger, H.; King, C.J. [Lawrence Berkeley Lab., CA (United States)

    1995-03-01

    The use of rock salt for deicing roads has many negative effects on automobiles, highway systems, and the environment. Calcium magnesium acetate, hence-forth denoted CMA, has been identified as a more desirable, environmentally benign solid deicer for high-ways, airport runaways, and similar applications. CMA is also of interest as an additive for scavenging sulfur in combustion processes so as to reduce emissions of sulfur oxides and as a catalyst for coal gasification. Different extractants (trioctylphosphine oxide and secondary, tertiary, and quaternary amines) and solid sorbents (tertiary and quaternary amines) were investigated as agents for recovery of acetic acid as part of a process for production of CMA from fermentation acetic acid. The pH and temperature dependencies for uptake of acetic acid by these extractants and sorbents were measured, along with the degrees of regeneration by aqueous suspensions of slaked dolomitic lime. These results enable identification of agents having optimal basicity. Among the extractants, the secondary amine Amberlite LA-2 gave the best combined performance for extraction and regeneration. Among the sorbents, a tertiary amine, Amberlite IRA-35, gave the best performance. Trioctylphosphine oxide does not maintain capacity in the pH range (about 6) most attractive for acetic acid fermentation. Slurred crushed dolomite is not sufficiently basic to accomplish regeneration.

  19. Safety and efficacy of roxatidine acetate. Evidence from pharmacodynamic and clinical trials.

    Science.gov (United States)

    Merki, H S; Bender, W; Labs, R

    1989-01-01

    The effects of a new H2-receptor antagonist, roxatidine acetate, have been investigated in both clinical and pharmacodynamic trials in Europe and the United States. A series of four double-blind randomized studies are reviewed, reporting the effects of different dose regimens of roxatidine acetate compared with ranitidine and placebo in healthy volunteers using continuous intragastric pH monitoring. These pharmacodynamic studies clearly demonstrate that roxatidine acetate is an effective gastric antisecretory agent, which is up to twice as potent as ranitidine. The results of several clinical studies of roxatidine acetate in patients with gastric as well as duodenal ulcer conducted in Europe, Japan, and the United States are also reviewed. These studies show that roxatidine acetate is comparable to other potent H2-receptor antagonists in terms of cumulative healing rates, pain relief, and safety. Overall, the pharmacodynamic and clinical data indicate that the efficacy of roxatidine acetate 75 mg twice-daily (b.i.d.) does not differ significantly from ranitidine 150 mg b.i.d. Roxatidine acetate is equally effective in the treatment of peptic disease including gastric ulcer, duodenal ulcer, and reflux esophagitis.

  20. Acetic acid bacteria in traditional balsamic vinegar: phenotypic traits relevant for starter cultures selection.

    Science.gov (United States)

    Gullo, Maria; Giudici, Paolo

    2008-06-30

    This review focuses on acetic acid bacteria in traditional balsamic vinegar process. Although several studies are available on acetic acid bacteria ecology, metabolism and nutritional requirements, their activity as well as their technological traits in homemade vinegars as traditional balsamic vinegar is not well known. The basic technology to oxidise cooked grape must to produce traditional balsamic vinegar is performed by the so called "seed-vinegar" that is a microbiologically undefined starter culture obtained from spontaneous acetification of previous raw material. Selected starter cultures are the main technological improvement in order to innovate traditional balsamic vinegar production but until now they are rarely applied. To develop acetic acid bacteria starter cultures, selection criteria have to take in account composition of raw material, acetic acid bacteria metabolic activities, applied technology and desired characteristics of the final product. For traditional balsamic vinegar, significative phenotypical traits of acetic acid bacteria have been highlighted. Basic traits are: ethanol preferred and efficient oxidation, fast rate of acetic acid production, tolerance to high concentration of acetic acid, no overoxidation and low pH resistance. Specific traits are tolerance to high sugar concentration and to a wide temperature range. Gluconacetobacter europaeus and Acetobacter malorum strains can be evaluated to develop selected starter cultures since they show one or more suitable characters.

  1. Acetic Acid Production by an Electrodialysis Fermentation Method with a Computerized Control System.

    Science.gov (United States)

    Nomura, Yoshiyuki; Iwahara, Masayoshi; Hongo, Motoyoshi

    1988-01-01

    In acetic acid fermentation by Acetobacter aceti, the acetic acid produced inhibits the production of acetic acid by this microorganism. To alleviate this inhibitory effect, we developed an electrodialysis fermentation method such that acetic acid is continuously removed from the broth. The fermentation unit has a computerized system for the control of the pH and the concentration of ethanol in the fermentation broth. The electrodialysis fermentation system resulted in improved cell growth and higher productivity over an extended period; the productivity exceeded that from non-pH-controlled fermentation. During electrodialysis fermentation in our system, 97.6 g of acetic acid was produced from 86.0 g of ethanol; the amount of acetic acid was about 2.4 times greater than that produced by non-pH-controlled fermentation (40.1 g of acetic acid produced from 33.8 g of ethanol). Maximum productivity of electrodialysis fermentation in our system was 2.13 g/h, a rate which was 1.35 times higher than that of non-pH-controlled fermentation (1.58 g/h).

  2. Effects of pH and acetic acid on homoacetic fermentation of lactate by Clostridium formicoaceticum.

    Science.gov (United States)

    Tang, I C; Okos, M R; Yang, S T

    1989-10-20

    Clostridium formicoaceticum homofermentatively converts lactate to acetate at 37 degrees C and pH 6.6-9.6. However, this fermentation is strongly inhibited by acetic acid at acidic pH. The specific growth rate of this organism decreased from a maximum at pH 7.6 to zero at pH 6.6. This inhibition effect was found to be attributed to both H(+) and undissociated acetic acid. At pH values below 7.6, the H(+) inhibited the fermentation following non-competitive inhibition kinetics. The acetic acid inhibition was found to be stronger at a lower medium pH. At pH 6.45-6.8, cell growth was found to be primarily limited by a maximum undissociated acetic acid concentration of 0.358 g/L (6mM). This indicates that the undissociated acid, not the dissociated acid, is the major acid inhibitor. At pH 7.6 or higher, this organism could tolerate acetate concentrations of higher than 0.8M, but salt (Na(+)) became a strong inhibitor at concentrations of higher than 0.4M. Acetic acid inhibition also can be represented by noncompetitive inhibition kinetics. A mathematical model for this homoacetic fermentation was also developed. This model can be used to simulate batch fermentation at any pH between 6.9 and 7.6.

  3. Beneficial Effect of Acetic Acid on the Xylose Utilization and Bacterial Cellulose Production by Gluconacetobacter xylinus.

    Science.gov (United States)

    Yang, Xiao-Yan; Huang, Chao; Guo, Hai-Jun; Xiong, Lian; Luo, Jun; Wang, Bo; Chen, Xue-Fang; Lin, Xiao-Qing; Chen, Xin-De

    2014-09-01

    In this work, acetic acid was found as one promising substrate to improve xylose utilization by Gluconacetobacter xylinus CH001. Also, with the help of adding acetic acid into medium, the bacterial cellulose (BC) production by G. xylinus was increased significantly. In the medium containing 3 g l(-1) acetic acid, the optimal xylose concentration for BC production was 20 g l(-1). In the medium containing 20 g l(-1) xylose, the xylose utilization and BC production by G. xylinus were stimulated by acetic acid within certain concentration. The highest BC yield (1.35 ± 0.06 g l(-1)) was obtained in the medium containing 20 g l(-1) xylose and 3 g l(-1) acetic acid after 14 days. This value was 6.17-fold higher than the yield (0.21 ± 0.01 g l(-1)) in the medium only containing 20 g l(-1) xylose. The results analyzed by FE-SEM, FTIR, and XRD showed that acetic acid affected little on the microscopic morphology and physicochemical characteristics of BC. Base on the phenomenon observed, lignocellulosic acid hydrolysates (xylose and acetic acid are main carbon sources present in it) could be considered as one potential substrate for BC production.

  4. Point mutation of H3/H4 histones affects acetic acid tolerance in Saccharomyces cerevisiae.

    Science.gov (United States)

    Liu, Xiangyong; Zhang, Xiaohua; Zhang, Zhaojie

    2014-10-10

    The molecular mechanism of acetic acid tolerance in yeast remains unclear despite of its importance for efficient cellulosic ethanol production. In this study, we examined the effects of histone H3/H4 point mutations on yeast acetic acid tolerance by comprehensively screening a histone H3/H4 mutant library. A total of 24 histone H3/H4 mutants (six acetic acid resistant and 18 sensitive) were identified. Compared to the wild-type strain, the histone acetic acid-resistant mutants exhibited improved ethanol fermentation performance under acetic acid stress. Genome-wide transcriptome analysis revealed that changes in the gene expression in the acetic acid-resistant mutants H3 K37A and H4 K16Q were mainly related to energy production, antioxidative stress. Our results provide novel insights into yeast acetic acid tolerance on the basis of histone, and suggest a novel approach to improve ethanol production by altering the histone H3/H4 sequences.

  5. Acetic acid in aged vinegar affects molecular targets for thrombus disease management.

    Science.gov (United States)

    Jing, Li; Yanyan, Zhang; Junfeng, Fan

    2015-08-01

    To elucidate the mechanism underlying the action of dietary vinegar on antithrombotic activity, acetic acid, the main acidic component of dietary vinegar, was used to determine antiplatelet and fibrinolytic activity. The results revealed that acetic acid significantly inhibits adenosine diphosphate (ADP)-, collagen-, thrombin-, and arachidonic acid (AA)-induced platelet aggregation. Acetic acid (2.00 mM) reduced AA-induced platelet aggregation to approximately 36.82 ± 1.31%, and vinegar (0.12 mL L(-1)) reduced the platelet aggregation induced by AA to 30.25 ± 1.34%. Further studies revealed that acetic acid exerts its effects by inhibiting cyclooxygenase-1 and the formation of thromboxane-A2. Organic acids including acetic acid, formic acid, lactic acid, citric acid, and malic acid also showed fibrinolytic activity; specifically, the fibrinolytic activity of acetic acid amounted to 1.866 IU urokinase per mL. Acetic acid exerted its fibrinolytic activity by activating plasminogen during fibrin crossing, thus leading to crosslinked fibrin degradation by the activated plasmin. These results suggest that organic acids in dietary vinegar play important roles in the prevention and cure of cardiovascular diseases.

  6. Antimicrobial and antioxidant activities of clove essential oil and eugenyl acetate produced by enzymatic esterification.

    Science.gov (United States)

    Vanin, Adriana B; Orlando, Tainara; Piazza, Suelen P; Puton, Bruna M S; Cansian, Rogério L; Oliveira, Debora; Paroul, Natalia

    2014-10-01

    This work reports the maximization of eugenyl acetate production by esterification of essential oil of clove in a solvent-free system using Novozym 435 as catalyst. The antimicrobial and antioxidant activities of clove essential oil and eugenyl acetate produced were determined. The conditions that maximized eugenyl acetate production were 60 °C, essential oil of clove to acetic anhydride ratio of 1:5, 150 rpm, and 10 wt% of enzyme, with a conversion of 99.87 %. A kinetic study was performed to assess the influence of substrates' molar ratio, enzyme concentration, and temperature on product yield. Results show that an excess of anhydride, enzyme concentration of 5.5 wt%, 50 °C, and essential oil of clove to acetic anhydride ratio of 1:5 afforded nearly a complete conversion after 2 h of reaction. Comparing the antibacterial activity of the essential oil of clove before and after esterification, we observed a decrease in the antimicrobial activity of eugenyl acetate, particularly with regard to minimum inhibitory concentration (MIC). Both eugenyl acetate and clove essential oil were most effective to the gram-negative than gram-positive bacteria group. The results showed a high antioxidant potential for essential oil before and particularly after the esterification reaction thus becoming an option for the formulation of new antioxidant products.

  7. A comparative study of biodegradation of vinyl acetate by environmental strains.

    Science.gov (United States)

    Greń, Izabela; Gąszczak, Agnieszka; Guzik, Urszula; Bartelmus, Grażyna; Labużek, Sylwia

    2011-06-01

    Four Gram-negative strains, E3_2001, EC1_2004, EC3_3502 and EC2_3502, previously isolated from soil samples, were subjected to comparative studies in order to select the best vinyl acetate degrader for waste gas treatment. Comparison of biochemical and physiological tests as well as the results of fatty acids analyses were comparable with the results of 16S rRNA gene sequence analyses. The isolated strains were identified as Pseudomonas putida EC3_2001, Pseudomonas putida EC1_2004, Achromobacter xylosoxidans EC3_3502 and Agrobacterium sp. EC2_3502 strains. Two additional strains, Pseudomonas fluorescens PCM 2123 and Stenotrophomonas malthophilia KB2, were used as controls. All described strains were able to use vinyl acetate as the only source of carbon and energy under aerobic as well as oxygen deficiency conditions. Esterase, alcohol dehydrogenase and aldehyde dehydrogenase were involved in vinyl acetate decomposition under aerobic conditions. Shorter degradation times of vinyl acetate were associated with accumulation of acetic acid, acetaldehyde and ethanol as intermediates in the culture fluids of EC3_2001 and KB2 strains. Complete aerobic degradation of vinyl acetate combined with a low increase in biomass was observed for EC3_2001 and EC1_2004 strains. In conclusion, P. putida EC1_2004 is proposed as the best vinyl acetate degrader for future waste gas treatment in trickle-bed bioreactors.

  8. Partial least square modeling of hydrolysis: analyzing the impacts of pH and acetate

    Institute of Scientific and Technical Information of China (English)

    L(U) Fan; HE Pin-jing; SHAO Li-ming

    2006-01-01

    pH and volatile fatty acids both might affect the further hydrolysis of particulate solid waste, which is the limiting-step of anaerobic digestion. To clarify the individual effects of pH and volatile fatty acids, batch experiments were conducted at fixed pH value (pH 5-9) with or without acetate (20 g/L). The hydrolysis efficiencies of carbohydrate and protein were evaluated by carbon and nitrogen content of solids, amylase activity and proteinase activity. The trend of carbohydrate hydrolysis with pH was not affected by the addition of acetate, following the sequence of pH 7>pH 8>pH 9>pH 6>pH 5; but the inhibition of acetate (20 g/L) was obvious by 10%-60 %. The evolution of residual nitrogen showed that the effect of pH on protein hydrolysis was minor, while the acetate was seriously inhibitory especially at alkali condition by 45%-100 %. The relationship between the factors (pH and acetate) and the response variables was evaluated by partial least square modeling (PLS). The PLS analysis demonstrated that the hydrolysis of carbohydrate was both affected by pH and acetate, with pH the more important factor. Therefore, the inhibition by acetate on carbohydrate hydrolysis was mainly due to the corresponding decline of pH, but the presence of acetate species, while the acetate species was the absolutely important factor for the hydrolysis of protein.

  9. Improved Acetic Acid Resistance in Saccharomyces cerevisiae by Overexpression of the WHI2 Gene Identified through Inverse Metabolic Engineering.

    Science.gov (United States)

    Chen, Yingying; Stabryla, Lisa; Wei, Na

    2016-01-29

    Development of acetic acid-resistant Saccharomyces cerevisiae is important for economically viable production of biofuels from lignocellulosic biomass, but the goal remains a critical challenge due to limited information on effective genetic perturbation targets for improving acetic acid resistance in the yeast. This study employed a genomic-library-based inverse metabolic engineering approach to successfully identify a novel gene target, WHI2 (encoding a cytoplasmatic globular scaffold protein), which elicited improved acetic acid resistance in S. cerevisiae. Overexpression of WHI2 significantly improved glucose and/or xylose fermentation under acetic acid stress in engineered yeast. The WHI2-overexpressing strain had 5-times-higher specific ethanol productivity than the control in glucose fermentation with acetic acid. Analysis of the expression of WHI2 gene products (including protein and transcript) determined that acetic acid induced endogenous expression of Whi2 in S. cerevisiae. Meanwhile, the whi2Δ mutant strain had substantially higher susceptibility to acetic acid than the wild type, suggesting the important role of Whi2 in the acetic acid response in S. cerevisiae. Additionally, overexpression of WHI2 and of a cognate phosphatase gene, PSR1, had a synergistic effect in improving acetic acid resistance, suggesting that Whi2 might function in combination with Psr1 to elicit the acetic acid resistance mechanism. These results improve our understanding of the yeast response to acetic acid stress and provide a new strategy to breed acetic acid-resistant yeast strains for renewable biofuel production.

  10. 36 CFR 1237.30 - How do agencies manage records on nitrocellulose-base and cellulose-acetate base film?

    Science.gov (United States)

    2010-07-01

    ... records on nitrocellulose-base and cellulose-acetate base film? 1237.30 Section 1237.30 Parks, Forests... and cellulose-acetate base film? (a) The nitrocellulose base, a substance akin to gun cotton, is... picture film and X-ray film—nitrocellulose base). (b) Agencies must inspect cellulose-acetate...

  11. 40 CFR 721.304 - Acetic acid, [(5-chloro-8-quinolinyl)oxy-], 1-methyl hexyl ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Acetic acid, , 1-methyl hexyl ester... Substances § 721.304 Acetic acid, , 1-methyl hexyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as acetic acid, -, 1-methylhexyl ester (PMN...

  12. Polygenic analysis and targeted improvement of the complex trait of high acetic acid tolerance in the yeast Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Meijnen, Jean-Paul; Randazzo, Paola; Foulquié-Moreno, María R; van den Brink, Joost; Vandecruys, Paul; Stojiljkovic, Marija; Dumortier, Françoise; Zalar, Polona; Boekhout, Teun; Gunde-Cimerman, Nina; Kokošar, Janez; Štajdohar, Miha; Curk, Tomaž; Petrovič, Uroš; Thevelein, Johan M

    2016-01-01

    BACKGROUND: Acetic acid is one of the major inhibitors in lignocellulose hydrolysates used for the production of second-generation bioethanol. Although several genes have been identified in laboratory yeast strains that are required for tolerance to acetic acid, the genetic basis of the high acetic

  13. Endometrial Histology of Depomedroxyprogesterone Acetate Users: A Pilot Study

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available Objective. To obtain pilot data on the endometrial histology of Depomedroxyprogesterone acetate (Depo-Provera, DMPA users experiencing breakthrough bleeding (BTB versus users with amenorrhea. To compare the endometrial histology of patients who used DMPA continuously for 3–12 months versus those who used it for 13 months or more. Methods. Cross-sectional study. Endometrial biopsy was obtained from all consenting patients who used DMPA for at least 3 months. Patients were divided into those with BTB in the last 3 months versus those with amenorrhea for at least 3 months. Histology results and duration of therapy were compared. Results. The proportion of women with chronic endometritis, uterine polyps, atrophic, proliferative, or progesterone-dominant endometrium did not differ between those DMPA users with BTB versus those with amenorrhea. Duration of therapy did not correlate with symptoms of BTB or endometrial histology. Chronic endometritis was the most common histologic finding (10/40, 25% and occurred more often in women experiencing BTB (35% versus 15% (RR 1.62 CI 0.91–2.87. Moreover, 45% of women with BTB had received DMPA for more than 12 months. Conclusions. BTB was more common than previously reported in women using DMPA for more than 12 months. Chronic endometritis, which may indicate an underlying infectious or intracavitary anatomic etiology, has not been previously reported as a frequent finding in DMPA users, and may be related to ethnic or other sociodemographic characteristics of our patient population. Further study to elucidate the etiology of chronic endometritis in these patients is warranted.

  14. On the microstructures of ethyl acetate/monoolein/water.

    Science.gov (United States)

    Imberg, Anna

    2006-12-01

    A phase diagram, describing the behavior of the polar lipid monoolein (MO), water, and ethyl acetate (EtAc), is here presented as well as results from small angle X-ray scattering. MO is found to have a solubility of 60wt.% in EtAc at 20 degrees C. No macroscopic aggregation of MO can, initially, be detected in the binary MO/EtAc solution even though MO forms solid crystals in concentrated samples when times goes by. In case of the ternary system small amounts of water, mainly bound to the lipid head groups, can be incorporated in the liquid EtAc/MO phase as water has a limited solubility in EtAc. For EtAc/water mass ratios below 2/3 EtAc is present into the reversed bicontinuous cubic and lamellar phases present in the binary MO/water system. To conclude, EtAc is mainly partitioned to the lipid membranes, with minor effects on spontaneous curvature. Hence, simple EtAc-addition has an effect similar to dehydration. For EtAc/water ratios above 2/3 the liquid crystalline phases dissolve. The phase behavior is here discussed in view of related phase behaviors for water-miscible solvent/MO/water systems. For instance, an interpretation of the swelling behavior of the sponge phase (L(3)), present in the water-miscible solvent(s)/MO/water systems, shows that solvents partitioned to the polar domains strongly increases the spontaneous curvature of the MO-films. The reason is probably weaker hydrophobic interactions in interfacial regions. As expected, in case of water-miscible solvents, the ternary phase behaviors can be understood by consider water and water-miscible solvent as one "mixed solvent".

  15. Alisol A 24-Acetate Prevents Hepatic Steatosis and Metabolic Disorders in HepG2 Cells

    Directory of Open Access Journals (Sweden)

    Lu Zeng

    2016-11-01

    Full Text Available Background: Non-alcoholic fatty liver disease (NAFLD is closely associated with metabolic disorders including hepatic lipid accumulation and inflammation. Alisol A 24-acetate, a triterpene from Alismatis rhizome, has multiple biologic activities such as hypolipidemic, anti-inflammatory and anti-diabetic. Thus we hypothesized that Alisol A 24 -acetate would have effect on NAFLD. The present study was conducted to investigate the therapeutic effects and potential mechanisms of Alisol A 24-acetate against hepatic steatosis in a free fatty acids (FFAs induced NAFLD cell model. Methods: This study was divided into four groups including Control group, Model group (FFA group, Alisol A 24-acetate (FFA+A group, Fenofibrate (FFA+F group. Preventive role of Alisol A 24-acetate was evaluated using 10µM Alisol A 24-acetate plus 1 mM FFA (oleate:palmitate=2:1 incubated with HepG2 cells for 24 h, which was determined by Oil Red O Staining, Oil Red O based colorimetric assay and intracellular triglyceride (TG content. Besides, the inflammatory cytokines tumor necrosis factor (TNF- α, interleukin (IL-6 levels as well as the protein and mRNA expressions that were involved in fatty acid synthesis and oxidation including Adiponectin, AMP-activated protein kinase (AMPK α, peroxisome proliferator-activated receptor (PPAR α, sterol regulatory element binding protein 1c (SREBP-1c, acetyl-CoA carboxylase (ACC, fatty acid synthase (FAS, carnitine palmitoyltransferase 1 (CPT1 and acyl coenzyme A oxidase 1 (ACOX1 were detected. Results: Alisol A 24-acetate significantly decreased the numbers of lipid droplets, Oil Red O lipid content, and intracellular TG content. Besides, inflammatory cytokines TNF-α, IL-6 levels were markedly inhibited by Alisol A 24-acetate. Furthermore, Alisol A 24-acetate effectively increased the protein and mRNA expressions of Adiponectin, the phosphorylation of AMPKα, CPT1 and ACOX1, whereas decreased SREBP-1c, the phosphorylation of ACC and

  16. CATALYSIS OF POLYSTYRENE N-HYDROXYL SULFONAMIDE FOR ESTERIFICATION OF BUTANOL WITH ACETIC ANHYDRIDE

    Institute of Scientific and Technical Information of China (English)

    LI Shufeng; LI Qian; YANG Xinlin; HUANG Wenqiang

    2004-01-01

    Polystyrene N-hydroxyl sulfonamide resin 1 was prepared and used to catalyze the esterification of n-butanol and acetic anhydride. The mechanism of catalytic esterification proved by IR spectra of the resins was found that O-H and N-H of the N-hydroxyl sulfonamide resin reacted with the acetic anhydride respectively to form the active intermediate polystyrene N,O-diacetyl sulfonamate which was cleaved by n-butanol to produce butyl acetate. The catalytic esterification by resin 1 was in good agreement with the kinetic model of "bi-bi-ping-pong" mechanism.

  17. Laboratory test of a prototype heat storage module based on stable supercooling of sodium acetate trihydrate

    DEFF Research Database (Denmark)

    Dannemand, Mark; Kong, Weiqiang; Fan, Jianhua;

    2015-01-01

    Laboratory test of a long term heat storage module utilizing the principle of stable supercooling of 199.5 kg of sodium acetate water mixture has been carried out. Avoiding phase separation of the incongruently melting salt hydrate by using the extra water principle increased the heat storage...... the supercooled sodium acetate water mixture was 194 kJ/kg of sodium acetate water mixture in the first test cycles dropping to 179 kJ/kg in the later test cycles. Instability of the supercooling occurred when the charging periods were short and in the last test cycles where the tube connecting the module...

  18. THE INFLUENCE OF CULTURE MEDIA ON ACETIC FERMENTATION WITH SELECTED Acetobacter STRAINS

    Directory of Open Access Journals (Sweden)

    MARIA CRISTIANA GARNAI

    2012-06-01

    Full Text Available We have systematically followed the efficiency of acetic fermentation, by cultivating 14 Acetobacter strains (previously isolated and identified, within a medium obtain out of ethanol and acetic acid, in various proportions, and utilizing corn extract (CE as a nutrient. The purpose of the research was to determine the resistance of the studied Acetobacter strains related to the composition of the cultivation media (acidity and alcohol content of the medium, as well as following the dynamics of the acetic fermentation by calculating the practical yield. The research led to optimal variants which may be industrially exploited in order to obtain vinegar.

  19. 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 of ethanol via acetaldehyde for the synthesis of acetic acid over a Cu based catalyst in a new process is reported. Specifically, we have studied a Cu on SiO2 catalyst which has shown very high selectivity to acetic acid via acetaldehyde compared to competing condensation routes....... 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...

  20. Studies on preparation and property of high-substitutional starch acetate hydrophode for the membrane material

    Institute of Scientific and Technical Information of China (English)

    ZUO Xiu-jin; DAI Xiao-min; MA Xiao-jun

    2005-01-01

    @@ Control-release technique is probably the most widely used,films control-release technique is the key of control-release technique,and film materials are the elements.The high-substitutional starch acetate was prepared by acetylation of starch with an acetic anhydride mixture.The best parameter of the technics (time of activation and reaction, reactant ratio) was obtained by orthogonal experiments.It was the hydrophode membrane material that property of the high-substitutional starch acetate was proofed.

  1. Electroencephalogram investigations of the disequilibrium syndrome during bicarbonate and acetate dialysis.

    Science.gov (United States)

    Hampl, H; Klopp, H W; Michels, N; Mahiout, A; Schilling, H; Wolfgruber, M; Schiller, R; Hanefeld, F; Kessel, M

    1983-01-01

    Continuous long-time electroencephalographic (EEG) monitoring was performed during acetate and bicarbonate dialysis in 20 patients. Persisting normal basic activity of the EEG without neurological symptoms was found only during the course of bicarbonate dialysis. However, in acetate dialysis, during the decrease of arterial CO2 tension (PaCO2), we registered EEG disturbances with moderate to severe slowing, dysrhythmic activity and high voltage discharges. The decrease in PaCO2 and the deterioration in EEG activity in the patients during acetate dialysis was concomitant with severe neurological alterations, e.g. the typical symptoms of so-called 'disequilibrium' causing a cessation of dialysis in three patients.

  2. A Novel Acetate Selective UV-Vis Chemosensor Containing a Tripodal Benzaldehydic-phenylhydrazone

    Institute of Scientific and Technical Information of China (English)

    QIAO Yan-Hong; LIN Hai; SHAO Jie; LIN Hua-Kuan

    2008-01-01

    A new colorimetric chemosensor 1 based on a tripodal benzaldehydic-phenylhydrazone selectively sensing acetate ion has been synthesized. The highly selective binding ability of receptor I to acetate ion over other studied anions was demonstrated by UV-Vis absorption spectroscopy in DMSO. Compared with other anions studied, its sorption spectrum change has occurred when receptor 1 was treated with other different guest anions (F-, Cl-, Br-,I-, H2PO4- and OH-). The Kass of receptor 1 binding with acetate ion is 1.69×104.

  3. Effect of acetic acid on rice seeds coated with rice husk ash

    OpenAIRE

    Lizandro Ciciliano Tavares; André Pich Brunes; Daniel Andrei Robe da Fonseca; Gizele Ingrid Gadotti; Lilian Madruga de Tunes; Géri Eduardo Meneghello; Antonio Carlos Souza Albuquerque Barros

    2013-01-01

    Flooded rice cultivation promotes anaerobic conditions, favoring the formation of short chain organic acids such as acetic acid, which may be toxic to the crop. The objective of this study was to evaluate the effect of acetic acid on rice seeds coated with rice husk ash. The experiment was arranged in a 2 x 5 x 5 factorial randomized design, with two cultivars (IRGA 424 and BRS Querência), five doses of coating material (0, 2, 3,4 e 5 g kg-1 seed) and five concentrations of acetic acid (0, 3,...

  4. Improvement on stability of square planar rhodium (Ⅰ) complexes for carbonylation of methanol to acetic acid

    Institute of Scientific and Technical Information of China (English)

    蒋华; 潘平来; 袁国卿; 陈新滋

    1999-01-01

    A series of square planar cis-dicarbonyl polymer coordinated rhodium complexes with uncoordinated donors near the central rhodium atoms for carbonylation of methanol to acetic acid are reported. Data of IR, XPS and thermal analysis show that these complexes are very stable. The intramolecular substitution reaction is proposed for their high stability. These complexes show excellent catalytic activity, selectivity and less erosion to the equipment for the methanol carbonylation to acetic acid. The distillation process may be used instead of flash vaporization in the manufacture of acetic acid, which reduces the investment on the equipment.

  5. Fixing of metallic acetates on an anion-exchange resin; Fixation d'acetates metalliques dans une resine echangeuse d'anions

    Energy Technology Data Exchange (ETDEWEB)

    Brigaudeau-Vaissiere, M. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etude Nucleaires

    1966-06-01

    After giving a brief review of the theoretical principles governing the fixation of anionic complexes of metallic elements on an anion exchange resin, we consider the particular case of uranyl acetate. By plotting the partition curves we have been able to calculate the exchange constants in the resin. By studying the changes in the logarithm of the limiting partition coefficient as a function of the logarithm of the free acetate ion concentration, it has been possible to calculate the dissociation constants for the complexes in solution. The fixation of a large number of metallic acetates has been studied. All the tests have been negative except in the case of mercury. For this reason we have been able to consider the possibility of separating uranium from a certain number of elements. Some of these separations are possible even in the presence of interfering anions such as chlorides which have a greater affinity for the resin than have the acetate ions. In the case of water-ethanol and water-isopropanol mixtures, we have improved the conditions under which copper acetate and mercury acetate may be fixed. This study has enabled us to calculate the dissociation constant for the CuAc{sub 3}{sup -} complex in the mixtures water +40% (by weight) isopropanol and water +50% (by weight) isopropanol. It should also make it possible to use separation conditions which could not hitherto be applied in aqueous media. (author) [French] Apres avoir rappele les principes theoriques de la fixation des complexes anioniques des elements metalliques dans une resine echangeuse d'anions, nous avons etudie tout particulierement le cas de l'acetate d'uranyle. Le trace des courbes de partage nous a permis de calculer les constantes d'echange dans la resine. L'etude des variations du logarithme du coefficient limite de partage avec le logarithme de la concentration des ions acetate libres nous a conduits aux calculs des constantes de dissociation des complexes en

  6. Advances in technologies for hydrogenation of acetic acid and acetates to ethanol%醋酸和醋酸酯加氢制乙醇技术进展

    Institute of Scientific and Technical Information of China (English)

    王彪; 王熙庭; 徐国辉

    2013-01-01

      Advances in the technologies for hydrogenation of acetic acid and acetates to ethanol were reviewed. The tow kinds of technology had their advantages and disadvantages, and both should be further improved and developed.%  综述了醋酸直接加氢制乙醇技术与醋酸酯化加氢制乙醇技术的研究进展,指出两种技术各有优缺点,都应进一步完善和发展。

  7. Conductivity of Cellulose Acetate Membranes from Pandan Duri Leaves (Pandanus tectorius for Li-ion Battery

    Directory of Open Access Journals (Sweden)

    Laksono Endang W.

    2016-01-01

    Full Text Available The purpose of this research is to know the influence of lithium chloride composition on membrane conductivity. Cellulose was extracted from pandan duri leaves (P. tectorius by dilute alkaline and bleaching with 0.5% NaOCl followed by synthesis of cellulose acetate using acetic anhydride as acetylating agent, acetic acid as solvent and sulfuric acid as catalyst. The membranes were prepared by casting polymer solution method and the composition of CA/LiCl were 60/40, 65/35, 70/30, 75/25, 80/20 and 100/0. Structural analysis was carried out by FTIR and X-ray diffraction. The conductivity was measured using Elkahfi 100. The highest conductivity of cellulose acetate membrane was 2.20 × 10-4 S cm-1 that measured at room temperature for 65/35 composition

  8. Isolation and Characterization Compounds From Hexane and Ethyl Acetate Fractions of Peperomia pellucida L.

    Directory of Open Access Journals (Sweden)

    Sri Hartati

    2015-09-01

    Full Text Available Peperomia pellucida was used traditionally in Indonesia for health treatment: wounds, boils, pimples, abscesses, abdominal pain, colic, gout, kidney, rheumatic pain, fatigue headache, furuncles, conjunctivitis and anti dermatogenic and also for dengue treatment. The isolation compounds from hexane and ethyl acetate fractions of Peperomia pellucida L. are conducted by maceration of the dry herbs sample with methanol and partition with hexane, ethyl acetate, butanol and water. The hexane and ethyl acetate fractions were fractionated by gravitation column chromatography and eluted successively with hexane, ethyl acetate and methanol by the gradient. The structure was elucidated base on spectroscopy data of NMR proton and carbon for one and two dimension, LCMS and FT-IR. The isolation founded three compounds are stigmasterol, analogue of pheophytin and β-sitosterol-D-glucopyranoside.

  9. Self-assembly of acetate adsorbates drives atomic rearrangement on the Au(110) surface

    Science.gov (United States)

    Hiebel, Fanny; Shong, Bonggeun; Chen, Wei; Madix, Robert J.; Kaxiras, Efthimios; Friend, Cynthia M.

    2016-10-01

    Weak inter-adsorbate interactions are shown to play a crucial role in determining surface structure, with major implications for its catalytic reactivity. This is exemplified here in the case of acetate bound to Au(110), where the small extra energy of the van der Waals interactions among the surface-bound groups drives massive restructuring of the underlying Au. Acetate is a key intermediate in electro-oxidation of CO2 and a poison in partial oxidation reactions. Metal atom migration originates at surface defects and is likely facilitated by weakened Au-Au interactions due to bonding with the acetate. Even though the acetate is a relatively small molecule, weak intermolecular interaction provides the energy required for molecular self-assembly and reorganization of the metal surface.

  10. Electrochemical evaluation of the inhibitory effects of acetic acid on Saccharomyces cerevisiae

    Institute of Scientific and Technical Information of China (English)

    Yuan Zhenhong; Zhao Jinsheng; Yan Yongjie; Yang Zhengyu

    2006-01-01

    A mediated electrochemical method was proposed for toxic evaluation of acetic acid on S. cerevisiae AS.380, and menadione/ferricyanide was chosen as the mediator system. The variance in electrochemical response in the absence and presence of increasing concentrations of acetic acid were used to indicate the inhibitory effects of weak acid on the yeast. The inhibitory effects of acetic acid on glucose consumption during menadione mediated reduction of ferricyanide were also measured for comparison purpose. The relative limiting current and the glucose consumption were reduced by 64.5 % and 61%, respectively, in the presence of 4g/L acetic acid at pH 4.0. The results showed that the electrochemical method can provide us with an appropriate and convenient tool for cytotoxic evaluation.

  11. Lipase-mediated conversion of vegetable oils into biodiesel using ethyl acetate as acyl acceptor

    Energy Technology Data Exchange (ETDEWEB)

    Modi, M.K.; Reddy, J.R.C.; Rao, B.V.S.K.; Prasad, R.B.N. [Indian Institute of Chemical Technology, Hyderabad (India). Division of Lipid Science and Technology

    2007-04-15

    Ethyl acetate was explored as an acyl acceptor for immobilized lipase-catalyzed preparation of biodiesel from the crude oils of Jatropha curcas (jatropha), Pongamia pinnata (karanj) and Helianthus annus (sunflower). The optimum reaction conditions for interesterification of the oils with ethyl acetate were 10% of Novozym-435 (immobilized Candida antarctica lipase B) based on oil weight, ethyl acetate to oil molar ratio of 11:1 and the reaction period of 12 h at 50 {sup o}C. The maximum yield of ethyl esters was 91.3%, 90% and 92.7% with crude jatropha, karanj and sunflower oils, respectively under the above optimum conditions. Reusability of the lipase over repeated cycles interesterification and ethanolysis was also investigated under standard reaction conditions. The relative activity of lipase could be well maintained over twelve repeated cycles with ethyl acetate while it reached to zero by 6th cycle when ethanol was used as an acyl acceptor. (author)

  12. Transesterification of Ethylene Carbonate with Dimethyl Terephthalate over Various Metal Acetate Catalysts

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The reaction between ethylene carbonate and dimethyl terephthalate was carried out for the simultaneous synthesis of dimethyl carbonate and poly( ethylene terephthalate). This reaction is an excellent chemical process that is environmentally friendly and produces no poisonous substance. The metal acetate catalysts used for this reaction are discussed in detail. Lithium acetate dihydrate was found to be a novel and efficient catalyst for this reaction. Compared with other metal acetates, lithium acetate dihydrate can attain a maximum catalytic activity at a lower concentration.When the reaction was carried out under the following conditions: the reaction temperature from 230 to 250 ℃, molar ratio of ethylene carbonate(EC) to dimethyl terephthalate(DMT) 3: 1, reaction time 3 h, and a catalyst amount of 0. 4% (molar fraction to DMT), the yield of dimethyl carbonate(DMC) was 79. 1%.

  13. 1-Methylpyrrolidine-2-acetic Acid is not a Precursor of Tropane Alkaloids.

    Science.gov (United States)

    Huang, M N; Abraham, T W; Kim, S H; Leete, E

    1996-02-01

    1-Methylpyrrolidine-2-acetic acid and related compounds were studied as precursors in the biosynthesis of the tropane alkaloids in Erythroxylum coca and Datura innoxia. (R,S)-[1',2-(13)C2,2-(14)C,(15)N]-1-methylpyrrolidine-2- acid, (R,S)-[1',2'-(13)C2,1'-(14)C]-1-methylpyrrolidine-2-acetic acid, (R,S) [1',2'-(13)C2,1-(14)C]-1-methylpyrrolidine-2-acetate, and (R,S)-+2'-(14)C] methylpyrrolidine-2-acetic acid N-acetylcysteamine thioester were synthesized an intact plants by leaf-planting or hydroponic-feeding. Specific incorporation of compounds into ( - )-hyoscyamine, ( - )-scopolamine, ( - )-cocaine and the biosynthetically related cuscohygrine were very low. These results indicate that 1-methylpyrrolidine acid is not an efficient precursor of tropane alkaloids.

  14. Laboratory Test of a Cylindrical Heat Storage Module with Water and Sodium Acetate Trihydrate

    DEFF Research Database (Denmark)

    Dannemand, Mark; Kong, Weiqiang; Johansen, Jakob Berg;

    2016-01-01

    Cylindrical heat storage modules with internal heat exchangers have been tested in a laboratory. The modules were filled with water and sodium acetate trihydrate with additives. The testing focused on the heat content of the storage material and the heat exchange capacity rate during charge...... of the module. For the tests with the phase change materials, the focus was furthermore on the stability of supercooling and cycling stability. Testing the module with sodium acetate trihydrate and 6.4% extra water showed that phase separation increased and the heat released after solidification of supercooled...... phase change material was reduced over 17 test cycles. The heat released after solidification of the supercooled sodium acetate trihydrate with thickening agent and graphite was stable over the test cycles. Stable supercooling was obtained in 7 out of 17 test cycles with the module with sodium acetate...

  15. Clinical studies on the use of roxatidine acetate for the treatment of peptic ulcer in Japan.

    Science.gov (United States)

    Inoue, M

    1988-01-01

    Roxatidine acetate is a novel H2-receptor antagonist with a chemical structure different to the earlier drugs of this type. It is a potent inhibitor of histamine-mediated gastric acid secretion and in animal models is 4 to 6 times as potent as cimetidine. In a multicentre double-blind clinical trial of over 700 patients with gastric or duodenal ulcers roxatidine acetate 75 mg twice daily and cimetidine 200mg four times daily produced endoscopically confirmed and subjective and objective healing rates in excess of 90% for both types of ulcer, with no significant difference between the treatments. Roxatidine acetate's efficacy in stomal ulcer (marginal ulcer) and reflux oesophagitis has been confirmed in non-comparative studies of up to 8 weeks' duration. The overall incidence of adverse reactions in 1623 patients treated with roxatidine acetate 75 mg twice daily was 1.7%, with skin rashes and constipation the most frequently reported side effects.

  16. Inhibitory effect of ethanol, acetic acid, propionic acid and butyric acid on fermentative hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bo; Wan, Wei; Wang, Jianlong [Laboratory of Environmental Technology, INET, Tsinghua University, Beijing 100084 (China)

    2008-12-15

    The inhibitory effect of added ethanol, acetic acid, propionic acid and butyric acid on fermentative hydrogen production by mixed cultures was investigated in batch tests using glucose as substrate. The experimental results showed that, at 35 C and initial pH 7.0, during the fermentative hydrogen production, the substrate degradation efficiency, hydrogen production potential, hydrogen yield and hydrogen production rate all trended to decrease with increasing added ethanol, acetic acid, propionic acid and butyric acid concentration from 0 to 300 mmol/L. The inhibitory effect of added ethanol on fermentative hydrogen production was smaller than those of added acetic acid, propionic acid and butyric acid. The modified Han-Levenspiel model could describe the inhibitory effects of added ethanol, acetic acid, propionic acid and butyric acid on fermentative hydrogen production rate in this study successfully. The modified Logistic model could describe the progress of cumulative hydrogen production. (author)

  17. Single-cell level based approach to investigate acetate metabolism during batch industrial fermentation

    DEFF Research Database (Denmark)

    Nierychlo, Marta; Larsen, Poul; Eriksen, Niels T.

    and control the overflow metabolism phenomenon in E. coli. Even though acetate formation by E. coli have been studied for more than three decades, the literature published presents the results based on the average measurement of the whole population. The averaged data can mask the distribution of the activity......Acetate is a product of Escherichia coli overflow metabolism when the bacteria are grown under aerobic conditions and glucose is present in excessive amount. It is an undesirable byproduct that affects growth, physiology, and performance of E. coli when used in industrial bioprocesses; its...... on the sub-population level. We hypothesized that during the fermentation process, bacterial subpopulation exist, which exhibit different metabolic strategies towards the acetate. In this study, pure culture of Escherichia coli MG1655 was used to investigate in situ acetate metabolism at single-cell level...

  18. SYNTHESIS OF POLY(VINYL ACETATE)-INTERCALATED GRAPHITE OXIDE BY AN IN SITU INTERCALATIVE POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    Ping-gui Liu; Peng Xiao; Min Xiao; Ke-cheng Gong

    2000-01-01

    Graphite oxide, a pseudo-two-dimensional solid in bulk form, was synthesized from natural graphite powder by oxidization with KMnO4 in concentrated H2SO4. The poly(vinyl acetate)-intercalated graphite oxide nano-composite was prepared by an in situ intercalative polymerization reaction, in which n-octanol-graphite oxide intercalation compounds were first obtained, vinyl acetate monomer was then dispersed into the interlayer of modified graphite oxide, followed by thermal polymerization of the monomer. It was experimentally shown that the c-axis space ofpoly(vinyl acetate)-intercalated graphite oxide was increased to 0.115 nm, which suggested there existed a monolayer of poly(vinyl acetate) chain between the layers of graphite oxide. The nanocomposite was also characterized with thermal analysis and FT-IR spectrometry.

  19. 1, 3-Dipolar Cycloaddition Reaction between Vinyl Acetate and N-Alkyl Hydroxypyridinium Halide

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    1, 3 Dipolar cycloaddition reaction between vinyl acetate and 3-hydroxypyridiniun betaine was performed under solid-liquid phase transfer catalytic condition. This reaction has been successfully used on the synthesis of an analogue of Bao-Gong-Teng A.

  20. Hydrogen peroxide resistance of Acetobacter pasteurianus NBRC3283 and its relationship to acetic acid fermentation.

    Science.gov (United States)

    Okamoto-Kainuma, Akiko; Ehata, Yasunori; Ikeda, Manami; Osono, Takemasa; Ishikawa, Morio; Kaga, Takayuki; Koizumi, Yukimichi

    2008-10-01

    The bacterium Acetobacter pasteurianus can ferment acetic acid, a process that proceeds at the risk of oxidative stress. To understand the stress response, we investigated catalase and OxyR in A. pasteurianus NBRC3283. This strain expresses only a KatE homolog as catalase, which is monofunctional and growth dependent. Disruption of the oxyR gene increased KatE activity, but both the katE and oxyR mutant strains showed greater sensitivity to hydrogen peroxide as compared to the parental strain. These mutant strains showed growth similar to the parental strain in the ethanol oxidizing phase, but their growth was delayed when cultured in the presence of acetic acid and of glycerol and during the acetic acid peroxidation phase. The results suggest that A. pasteurianus cells show different oxidative stress responses between the metabolism via the membrane oxidizing pathway and that via the general aerobic pathway during acetic acid fermentation.

  1. Impact of acetic acid concentration of fermented liquid feed on growth performance of piglets

    DEFF Research Database (Denmark)

    Canibe, Nuria; Pedersen, Anni Øyan; Jensen, Bent Borg

    2010-01-01

    of microbial metabolites, namely acetic acid, possibly in combination with low feed pH, has been suggested to be determinant in reducing feed intake by impairing palatability. However, this hypothesis has never been investigated. A study was carried out to determine the impact of increasing levels of acetic...... acid in FLF on feed intake of weaners. Three experimental FLF diets were prepared to contain varying levels of acetic acid (30, 60, and 120 mM). Twenty piglets per treatment, weaned at 4 weeks of age and housed individually, were fed the experimental diets during six weeks starting at weaning. Feed...... intake and body weight were registered weekly. The results showed that high acetic acid concentration in FLF, accompanied by a slight lower pH level, tended to decrease feed intake without affecting body weight gain. This discrepancy could partly be explained by the difficulty in measuring accurately...

  2. Acetic acid production from marine algae. Progress report No. 2, September 30 to December 31, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Sanderson, J E; Wise, D L

    1978-03-10

    Preliminary results on the production of acetic acid from marine algae by anaerobic fermentation indicates that the rate is quite fast. First order rate constants of 0.77 day/sup -1/ have been observed. This rate constant gives a half-life of less than one day. In other words, with a properly designed product removal system a five day retention time would yield 98% of theoretical conversion. Determination of the theoretical conversion of marine algae to acetic acid is the subject of much experimentation. The production of one acetic acid molecule (or equivalent in higher organic acids) for each three carbon atoms in the substrate has been achieved; but it is possible that with a mixed culture more than one acetic acid molecule may be produced for each three carbons in the substrate.

  3. Tsuji-Trost N-allylation with allylic acetates using cellulose-Pd catalyst

    Science.gov (United States)

    Allylic amines are synthesized using heterogeneous cellulose-Pd catalyst via N-allylation of amines; aliphatic and benzyl amines undergo facile reaction with substituted and unsubstituted allyl acetates in high yields.

  4. Lithium amide assisted asymmetric Mannich-type reactions of menthyl acetate with PMP-aldimines.

    Science.gov (United States)

    Hata, Seiji; Iguchi, Mayu; Iwasawa, Tetsuo; Yamada, Ken-ichi; Tomioka, Kiyoshi

    2004-05-27

    A lithium enolate of menthyl acetate added to PMP-imines, in the presence of an equimolar amount of lithium diisopropylamide, affords the Mannich-type addition products in high stereoselectivity. [reaction--see text

  5. MODIFICATION OF ETHYLENE-VINYL ACETATE COPOLYMER AND ITS EFFECTS ON THE PERMEABILITY OF SOME STEROIDS

    Institute of Scientific and Technical Information of China (English)

    LINWu; FANGZhen; JINZhao-Ying

    1989-01-01

    Ethyleae-vinyl acetate copolymer ( EVA ) was mechanically blended with methylvinyl siloxane in order to increase the permeability of some steroids and to obtain an ideal material with membrane-controlled release of steroids from the intrauterine devices

  6. Experimental investigations on heat content of supercooled sodium acetate trihydrate by a simple heat loss method

    DEFF Research Database (Denmark)

    Kong, Weiqiang; Dannemand, Mark; Johansen, Jakob Berg

    2016-01-01

    to suffer from phase separation which is the phenomenon where anhydrous salt settles to the bottom over time. This happens especially in supercooled state. The heat released from the crystallization of supercooled sodium acetate trihydrate with phase separation will be lower than the heat released from...... sodium acetate trihydrate without phase separation. Possible ways of avoiding or reducing the problem of phase separation were investigated. A wide variety of composites of sodium acetate trihydrate with additives including extra water, thickening agents, solid and liquid polymers have been......, 0.3–0.5 % (wt.%) Xanthan Gum or 1–2% (wt.%) of some solid or liquid polymers as additives had significantly higher heat contents compared to samples of sodium acetate trihydrate suffering from phase separation....

  7. Production of oils from acetic acid by the oleaginous yeast Cryptococcus curvatus.

    Science.gov (United States)

    Christophe, G; Deo, J Lara; Kumar, V; Nouaille, R; Fontanille, P; Larroche, C

    2012-07-01

    The feasibility of the conversion of acetic acid, a metabolite commonly obtained during anaerobic fermentation processes, into oils using the yeast Cryptococcus curvatus was reported. This microorganism exhibited very slow growth rates on acetate as carbon source, which led to design a two-stage cultivation process. The first consisted of cell growth on glucose as carbon source until its complete exhaustion. The second step involved the use of acetate as carbon source under nitrogen limitation in order to induce lipid accumulation. A typical experiment performed in a bioreactor involved a preliminary yeast growth with a glucose initial concentration of 15 g/L glucose. Further additions of acetate and nitrogen source allowed a final lipid accumulation up to 50% (w/w). These promising results demonstrated the suitability of the technique proposed.

  8. Synthesis of 2-(Benzodioxol-2-yl)acetic Acids as PPARδ Agonists

    Institute of Scientific and Technical Information of China (English)

    Jian Lei KANG; Zhi Bing ZHENG; Dan QIN; Li Li WANG; Song LI

    2006-01-01

    A new series of compounds, 2-(benzodioxol-2-yl)acetic acids, have been synthesized. Their structures were confirmed by MS and 1H-NMR. The preliminary pharmacological screening showed that these compounds exhibited potent human PPARδ agonist activities.

  9. Oxidative aromatization of Hantzsch 1,4-dihydropyridines by aqueous hydrogen peroxide-acetic acid

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A simple method for the oxidative aromatization of Hantzsch 1,4-dihydropyridines to the corresponding pyridines is achieved by using hydrogen peroxide as green oxidant and acetic acid as catalyst in aqueous solution.

  10. Kinetics of esterification of methanol and acetic acid with mineral homogeneous acid catalyst

    Institute of Scientific and Technical Information of China (English)

    Mallaiah Mekala; Venkat Reddy Goli

    2015-01-01

    In this work, esterification of acetic acid and methanol to synthesize methyl acetate in a batch stirred reactor is studied in the temperature range of 305.15–333.15 K. Sulfuric acid is used as the homogeneous catalyst with concentrations ranging from 0.0633 mol·L−1 to 0.3268 mol·L−1. The feed molar ratio of acetic acid to methanol is varied from 1:1 to 1:4. The influences of temperature, catalyst concentration and reactant concentration on the reaction rate are investigated. A second order kinetic rate equation is used to correlate the experimental data. The forward and backward reaction rate constants and activation energies are determined from the Arrhenius plot. The developed kinetic model is compared with the models in literature. The developed kinetic equation is useful for the simulation of reactive distillation column for the synthesis of methyl acetate.

  11. Production of Specifically Labeled Compounds by Methanobacterium espanolae Grown on H2-CO2 plus [13C]Acetate

    OpenAIRE

    Patel, Girishchandra B; Sprott, Dennis; Ekiel, Irena

    1993-01-01

    Methanobacterium espanolae, an acidiphilic methanogen, required acetate for maximal growth on H2-CO2. In the presence of 5 to 15 mM acetate, at a growth pH of 5.5, the μmax was 0.05 h-1. M. espanolae consumed 12.3 mM acetate during 96 h of incubation at 35°C with shaking at 100 rpm. At initial acetate levels of 2.5 to 10.0 mM, the amount of biomass produced was dependent on the amount of acetate in the medium. 13C nuclear magnetic resonance spectra of protein hydrolysates obtained from cultur...

  12. Synthesis and characterization of anhydrous rare earth metal nitrates, rare earth acetates and rare earth oxyacetates; Synthese und Charakterisierung wasserfreier Seltenerdmetall-Nitrate, -Acetate und -Oxyacetate

    Energy Technology Data Exchange (ETDEWEB)

    Heinrichs, Christina

    2013-10-29

    Anhydrous rare-earth metal (RE) nitrates, RE nitrate monohydrates and RE acetates were synthesized by thermal dehydration of RE nitrate hydrates and RE acetate hydrates in an argon flow or vacuum. RE oxyacetates were synthesized by thermal decomposition of RE acetates. Furthermore praseodymium carbonate hydroxide was synthesized by heating Pr carbonate hydrate. The compounds were analyzed by X-ray powder diffraction and, for selected examples, measurements with high-resolution synchrotron radiation were performed. Three new crystal structure types were found for RE nitrates: RE(NO{sub 3}){sub 3} with RE = La - Sm (type I) crystallize monoclinically in space group C2/c with Z = 16 (CN = 12, 11). RE(NO{sub 3}){sub 3} with RE = Y, Eu - Yb (type II) crystallize monoclinically in space group P2{sub 1}/c with Z = 4 (CN = 10) and Lu(NO{sub 3}){sub 3} (type III) monoclinically in space group I2/a with Z = 16 (CN = 8, 7). With decreasing CN (coordination number) a structural trend within the RE nitrates is observed: The RE nitrates of type I with the largest RE{sup 3+} cations build a three-dimensional network, the RE nitrates of type II form close packed layers and the preliminary structural model of Lu(NO{sub 3}){sub 3} (type III) with the smallest RE{sup 3+} cation shows layers and chains. The product of the dehydration of Sc(NO{sub 3}){sub 3} . n H{sub 2}O was indexed monoclinically in space group P2{sub 1}/c. Monohydrates RE(NO{sub 3}){sub 3} . H{sub 2}O with RE = Dy - Yb crystallize isotypically with Y(NO{sub 3}){sub 3} . H{sub 2}O in the triclinic space group P anti 1 with Z = 2 (CN = 9). Pr(CH{sub 3}CO{sub 2}){sub 3} does not crystallize in the known Pr acetate type but in the trigonal space group R anti 3 with Z = 18 (CN = 10) isotypically with the La acetate type which was only known for La(CH{sub 3}CO{sub 2}){sub 3} and Ce(CH{sub 3}CO{sub 2}){sub 3} up to now. In addition to the known Ho acetate type a new crystal structure type (Ho acetate type II) was found for

  13. Cervicovaginal Fluid Acetate: A Metabolite Marker of Preterm Birth in Symptomatic Pregnant Women

    Science.gov (United States)

    Amabebe, Emmanuel; Reynolds, Steven; Stern, Victoria; Stafford, Graham; Paley, Martyn; Anumba, Dilly O. C.

    2016-01-01

    Changes in vaginal microbiota that is associated with preterm birth (PTB) leave specific metabolite fingerprints that can be detected in the cervicovaginal fluid (CVF) using metabolomics techniques. In this study, we characterize and validate the CVF metabolite profile of pregnant women presenting with symptoms of threatened preterm labor (PTL) by both 1H-nuclear magnetic resonance spectroscopy (NMR) and enzyme-based spectrophotometry. We also determine their predictive capacity for PTB, singly, and in combination, with current clinical screening tools – cervicovaginal fetal fibronectin (FFN) and ultrasound cervical length (CL). CVF was obtained by high-vaginal swabs from 82 pregnant women with intact fetal membranes presenting between 24 and 36 weeks gestation with symptoms of threatened, but not established, PTL. Dissolved CVF samples were scanned with a 400 MHz NMR spectrometer. Acetate and other metabolites were identified in the NMR spectrum, integrated for peak area, and normalized to the total spectrum integral. To confirm and validate our observations, acetate concentrations (AceConc) were also determined from a randomly-selected subset of the same samples (n = 57), by spectrophotometric absorption of NADH using an acetic acid assay kit. CVF FFN level, transvaginal ultrasound CL, and vaginal pH were also ascertained. Acetate normalized integral and AceConc were significantly higher in the women who delivered preterm compared to their term counterparts (P = 0.002 and P = 0.006, respectively). The 1H-NMR-derived acetate integrals were strongly correlated with the AceConc estimated by spectrophotometry (r = 0.69; P 0.53 g/l), and of delivery within 2 weeks of the index assessment (acetate integral: AUC = 0.77, 95% CI = 0.58–0.96; AceConc: AUC = 0.68, 95% CI = 0.5–0.9). The predictive accuracy of CVF acetate was similar to CL and FFN. The combination of CVF acetate, FFN, and ultrasound CL in a binary logistic

  14. Growing and laying performance of Japanese quail fed diet supplemented with different concentrations of acetic acid

    Directory of Open Access Journals (Sweden)

    Youssef A. Attia

    2013-04-01

    Full Text Available In order to evaluate the effect of acetic acid on growing and laying performance of Japanese Quail (JQ, 180 15-day-old JQ were divided into 4 groups. During the growing (15-42 days of age and laying (43-84 days of age periods, the groups fed the same basal diets supplemented with 0, 1.5, 3 and 6% of acetic acid. Each diet was fed to five replicates of 9 JQ (3 males:6 females during the growing period. During the laying period, 128 birds were housed in 32 cages (4 birds per cage, 1 male and 3 females, 8 replicates per treatment. Birds were housed in wire cages (46L×43W×20H cm in an open room. Acetic acid supplementation at 3% in the diets significantly increased the growth and laying rate and the Haugh unit score. The liver percentage significantly decreased with acetic acid at 6%. Acetic acid at 3% significantly increased hemoglobin concentrations at 6 weeks of age and increased weight of day old chicks hatched. Acetic acid affected the immune system as manifested by an excess of cellular reactions in the intestine as well as lymphoid hyperplasia in the spleen tissue. Degenerative changes in the covering epithelium of the intestinal villi were noted at the 6% concentration of acetic acid. Hepatocyte vacuolation and fatty changes were also observed at this concentration of treatment. In conclusion, 3% acetic acid may be used as a feed supplement for JQ during the growing and laying period to improve the productive performance.

  15. Interspecies acetate transfer influences the extent of anaerobic benzoate degradation by syntrophic consortia

    Energy Technology Data Exchange (ETDEWEB)

    Warikoo, V.; McInerney, M.J.; Suflita, J.M. [and others

    1997-03-01

    Benzoate degradation by an anaerobic, syntrophic bacterium, strain SB, in coculture with Desulfovibrio strain G-11 reached a threshold value which depended on the amount of acetate added, and ranged from about 2.5 to 29.9 {mu}M. Increasing acetate concentrations also uncompetitively inhibited benzoate degradation. The apparent V{sub max} and K{sub m} for benzoate degradation decreased with increasing acetate concentration, but the benzoate degradation capacity (V{sub max}/K{sub m}) of cell suspensions remained comparable. The addition of an acetate-using bacterium to cocultures after the threshold was reached resulted in the degradation of benzoate to below the detection limit. Mathematical simulations showed that the benzoate threshold was not predicted by the inhibitory effect of acetate on benzoate degradation kinetics. With nitrate instead of sulfate as the terminal electron acceptor, no benzoate threshold was observed in the presence of 20 mM acetate even though the degradation capacity was lower with nitrate than with sulfate. When strain SB was grown with a hydrogen-using partner that had a 5-fold lower hydrogen utilization capacity, a 5 to 9-fold lower the benzoate degradation capacity was observed compared to SB/G-11 cocultures. The Gibb`s free energy for benzoate degradation was less negative in cell suspensions with threshold compared to those without threshold. These studies showed that the threshold was not a function of the inhibition of benzoate degradation capacity by acetate, or the toxicity of the undissociated form of acetate. Rather a critical or minimal Gibb`s free energy may exist where thermodynamic constraints preclude further benzoate degradation.

  16. Complex refractive index of starch acetate used as a biodegradable pigment and filler of paper

    Science.gov (United States)

    Karvinen, Petri; Oksman, Antti; Silvennoinen, Raimo; Mikkonen, Hannu

    2007-05-01

    Complex refractive index of strongly depolarizing starch acetate is investigated as a function of bulk package density, which is compulsory parameter in analysis of light scattering from nanoscale starch acetate pigments and fillers. The measurements were made using a laser-goniometer and spectrophotometer to gain data for refractive index analysis according to the Brewster's law and Fresnel equations. The real part of refractive index was verified by microscopic immersion method.

  17. 11C-acetate PET imaging in patients with multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Kazushiro Takata

    Full Text Available BACKGROUND: Activation of glial cells is a cardinal feature in multiple sclerosis (MS pathology, and acetate has been reported to be selectively uptaken by astrocytes in the CNS. The aim of this study was to investigate the efficacy of PET with (11C-acetate for MS diagnosis. MATERIALS AND METHODS: Six patients with relapsing-remitting MS and 6 healthy volunteers (HV were enrolled. The (11C-acetate brain uptake on PET was measured in patients with MS and HV. Volume-of-interest analysis of cerebral gray and white matter based on the segmentation technique for co-registered MRI and voxel-based statistical parametric analysis were performed. Correlation between 11C-acetate uptake and the lesion number in T1- and T2- weighted MR images were also assessed. RESULTS: The standardized uptake value (SUV of 11C-acetate was increased in both white and gray matter in MS patients compared to HV. Voxel-based statistical analysis revealed a significantly increased SUV relative to that in the bilateral thalami (SUVt in a broad area of white matter, particularly in the subcortical white matter of MS patients. The numbers of T2 lesions and T1 black holes were significantly correlated with SUV of (11C-acetate in white and gray matter. CONCLUSIONS: The 11C-acetate uptake significantly increased in MS patients and correlated to the number of MRI lesions. These preliminary data suggest that (11C-acetate PET can be a useful clinical examination for MS patients.

  18. The Fate of Acetic Acid during Glucose Co-Metabolism by the Spoilage Yeast Zygosaccharomyces bailii

    OpenAIRE

    Fernando Rodrigues; Maria João Sousa; Paula Ludovico; Helena Santos; Manuela Côrte-Real; Cecília Leão

    2012-01-01

    Zygosaccharomyces bailii is one of the most widely represented spoilage yeast species, being able to metabolise acetic acid in the presence of glucose. To clarify whether simultaneous utilisation of the two substrates affects growth efficiency, we examined growth in single- and mixed-substrate cultures with glucose and acetic acid. Our findings indicate that the biomass yield in the first phase of growth is the result of the weighted sum of the respective biomass yields on single-substrate me...

  19. Therapeutic approach in patients with concomitant disease/drug--drug interactions (roxatidine acetate).

    Science.gov (United States)

    Collins, J D

    1988-01-01

    Possible mechanisms of drug interactions with H2-antagonists are outlined. The mode of action of roxatidine acetate on hepatic microsomal enzymes is contrasted with those of cimetidine and ranitidine, and their differing structure-activity relationships are discussed. In the light of the mechanisms of drug interactions with H2-antagonists, clinical studies with roxatidine acetate are contrasted with published interaction data of cimetidine and ranitidine. The therapeutic consequences of these data are considered.

  20. KRAFT MILL BIOREFINERY TO PRODUCE ACETIC ACID AND ETHANOL: TECHNICAL ECONOMIC ANALYSIS

    OpenAIRE

    Haibo Mao; Joseph M. Genco; Adriaan van Heiningen; Hemant Pendse

    2010-01-01

    The “near neutral hemicellulose extraction process” involves extraction of hemicellulose using green liquor prior to kraft pulping. Ancillary unit operations include hydrolysis of the extracted carbohydrates using sulfuric acid, removal of extracted lignin, liquid-liquid extraction of acetic acid, liming followed by separation of gypsum, fermentation of C5 and C6 sugars, and upgrading the acetic acid and ethanol products by distillation. The process described here is a variant of the “near n...

  1. Zymomonas with improved ethanol production in medium containing concentrated sugars and acetate

    Science.gov (United States)

    Caimi, Perry G.; Chou, Yat-Chen; Franden, Mary Ann; Knoke, Kyle; Tao, Luan; Viitanen, Paul V.; Zhang, Min; Zhang, Yuying

    2011-03-01

    Through screening of a Zymomonas mutant library the himA gene was found to be involved in the inhibitory effect of acetate on Zymomonas performance. Xylose-utilizing Zymomonas strains further engineered to reduce activity of the himA gene were found to have increased ethanol production in comparison to a parental strain, when cultured in mixed-sugars medium comprising xylose, and, in particular, in the presence of acetate.

  2. Determination of Bioactive Components of Ethyl Acetate Fraction of Punica granatum Rind Extract

    OpenAIRE

    J. Sangeetha; K. Vijayalakshmi

    2011-01-01

    Punica granatum belongs to a Punicaceae family. The Punica granatum is valued as a powerful medicinal plant and used in folk medicines. Hence the present investigation was carried out to determine the possible chemical components from ethyl acetate fraction of Punica granatum rind extract by GC-MS Technique. This analysis revealed that ethyl acetate fraction of Punica granatum rind extract contain Pyrogallol (41.88%), 5-Hydroxymethylfurfural (14.10%), D-Allose (9.17%), 2-Methoxy-1, 4-Benzened...

  3. Impact of Biofield Treatment on Chemical and Thermal Properties of Cellulose and Cellulose Acetate

    OpenAIRE

    Trivedi, Mahendra Kumar

    2015-01-01

    Cellulose being an excellent biopolymer has cemented its place firmly in many industries as a coating material, textile, composites, and biomaterial applications. In the present study, we have investigated the effect of biofield treatment on physicochemical properties of cellulose and cellulose acetate. The cellulose and cellulose acetate were exposed to biofield and further the chemical and thermal properties were investigated. X-ray diffraction study asserted that the biofield treatment did...

  4. Comparison of Cultivable Acetic Acid Bacterial Microbiota in Organic and Conventional Apple Cider Vinegar

    OpenAIRE

    2016-01-01

    Organic apple cider vinegar is produced from apples that go through very restricted treatment in orchard. During the first stage of the process, the sugars from apples are fermented by yeasts to cider. The produced ethanol is used as a substrate by acetic acid bacteria in a second separated bioprocess. In both, the organic and conventional apple cider vinegars the ethanol oxidation to acetic acid is initiated by native microbiota that survived alcohol fermentation. We compared the cultivable ...

  5. Synthesis of 2,6-diaminopyridine substituted -oxoketene ,-acetals: Crystal structure and hydrogen bonding interactions

    Indian Academy of Sciences (India)

    Okram Mukherjee Singh; Laishram Ronibala Devi; Neeladri Das

    2013-09-01

    Polyaza -oxoketene ,-acetals can exist as either enamino or imino tautomeric forms. Based on the spectroscopic data and structural analysis of one of the ,-acetals, the stereochemistry was unambiguously assigned as an all--configuration. The crystal structure confirms the enamino structure and shows extensive use of C-H…X (X = N, O, and S) weak hydrogen bonding interactions, thereby generating a 3-dimensional network in solid state.

  6. THE INFLUENCE OF CULTURE MEDIA ON ACETIC FERMENTATION WITH SELECTED Acetobacter STRAINS

    OpenAIRE

    MARIA CRISTIANA GARNAI

    2012-01-01

    We have systematically followed the efficiency of acetic fermentation, by cultivating 14 Acetobacter strains (previously isolated and identified), within a medium obtain out of ethanol and acetic acid, in various proportions, and utilizing corn extract (CE) as a nutrient. The purpose of the research was to determine the resistance of the studied Acetobacter strains related to the composition of the cultivation media (acidity and alcohol content of the medium), as well as following the dy...

  7. KINETIC OF ESTERIFICATION OF ETHYL ALCOHOL BY ACETIC ACID ON A CATALYTIC RESIN

    Directory of Open Access Journals (Sweden)

    Erol İNCE

    2002-01-01

    Full Text Available The conversion kinetics of diluted acetic acid to ethyl acetate by ethanol esterification in a batch reactor in liquid phase with an acidic polymer catalyst (lewatit series was studied. The intrinsic rate constants have been correlated with the reaction temperature, concentration of catalyst, initial ratios of reactants and initial water concentrations. The kinetic analysis was restricted to the system at hand in which a liquid and vapor phase are at equilibrium.

  8. Capillary gas chromatographic analysis of alditol acetates of neutral and amino sugars in bacterial cell walls.

    Science.gov (United States)

    Fox, A; Morgan, S L; Hudson, J R; Zhu, Z T; Lau, P Y

    1983-02-18

    Several improvements in the preparation of alditol acetates of neutral and amino sugars and in the preparation of glass capillary columns for their separation are described. Modifications in sample preparation permitted the simultaneous processing of multiple samples and eliminated extraneous background peaks. Efficient and inert columns were tailor-made for the separation of alditol acetates of neutral and amino sugars by leaching glass capillaries with aqueous hydrochloric acid and dynamically coating with SP-2330.

  9. Polymerization of vinyl acetate in bulk and emulsion by gamma irradiation

    Science.gov (United States)

    Mesquita, Andrea C.; Mori, Manoel N.; Andrade e Silva, Leonardo G.

    2004-09-01

    The vinyl acetate polymerization to produce poly(vinyl acetate) was carried out in bulk and emulsion using a 60Co gamma irradiator Gammacell-220 type. The irradiation was carried out in a dose rate of 5.25 and 5.30 kGy/h, respectively. The polymers obtained were characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimeter (DSC) and gel permeation chromatography (GPC). Tests of density, hardness and Vicat softening temperature were carried out.

  10. SINOPEC,BP TO LAUNCH ACETIC ACID JOINT VENTURE IN NANJING

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Sinopec Corp and BP signed a 50%-50% joint venture contract on March 15 to build a world-class 500,000-ton acetic acid plant in Nanjing, the capital of East China's Jiangsu Province. The joint venture, which is expected to be on stream in the second half of 2007,will adopt BP's world leading CativaR technology to make this project become a acetic acid production base with great competitiveness.

  11. Depo-Provera (depot medroxyprogesterone acetate use after bariatric surgery

    Directory of Open Access Journals (Sweden)

    Lam C

    2016-09-01

    Full Text Available Clarissa Lam,1 Amitasrigowri S Murthy2,3 1New York University School of Medicine, 2Department of Obstetrics and Gynecology, Bellevue Hospital Center, New York University School of Medicine, 3New York University Langone Medical Center, New York, NY, USA Abstract: In the US, obesity rates are increasing greatly. The Centers for Disease Control and Prevention estimates that 68.5% of Americans, including 63.9% of adult women older than 20 years, are overweight (body mass index between 25 kg/m2 and 29.9 kg/m2 or obese (body mass index >30 kg/m2. In light of this, it is not surprising that the rates of bariatric surgery have also been increasing. When considering the metabolic changes associated with both bariatric surgery and contraceptive use, in combination with the unique medical considerations of obese women, it is indisputable that clear guidelines are needed when counseling obese patients of reproductive age after bariatric surgery. In this literature review, we focus on depot medroxyprogesterone acetate (DMPA and the implications of its use in obese women, preweight and postweight loss following bariatric surgery. Both DMPA use and bariatric surgery are known to cause bone loss, but it is still unclear whether there is an additive effect of the two factors on bone loss and whether either of these factors directly leads to an increased risk of bone fracture. The current consensus guidelines do not impose a restriction on the use of DMPA after bariatric surgery. DMPA use is associated with weight gain, and it is unclear whether weight loss blunting occurs with the use of DMPA after bariatric surgery. Prior studies had demonstrated an association with weight gain in adolescents, and therefore, those prescribing DMPA use after bariatric surgery in adolescents should proceed with caution. Adult women do not have a similar response to the use of DMPA. DMPA use has rarely been associated with increased risk of venous thromboembolism (VTE. The

  12. Batch and continuous culture-based selection strategies for acetic acid tolerance in xylose-fermenting Saccharomyces cerevisiae.

    Science.gov (United States)

    Wright, Jeremiah; Bellissimi, Eleonora; de Hulster, Erik; Wagner, Andreas; Pronk, Jack T; van Maris, Antonius J A

    2011-05-01

    Acetic acid tolerance of Saccharomyces cerevisiae is crucial for the production of bioethanol and other bulk chemicals from lignocellulosic plant-biomass hydrolysates, especially at a low pH. This study explores two evolutionary engineering strategies for the improvement of acetic acid tolerance of the xylose-fermenting S. cerevisiae RWB218, whose anaerobic growth on xylose at pH 4 is inhibited at acetic acid concentrations >1 g L(-1) : (1) sequential anaerobic, batch cultivation (pH 4) at increasing acetic acid concentrations and (2) prolonged anaerobic continuous cultivation without pH control, in which acidification by ammonium assimilation generates selective pressure for acetic acid tolerance. After c. 400 generations, the sequential-batch and continuous selection cultures grew on xylose at pH≤4 with 6 and 5 g L(-1) acetic acid, respectively. In the continuous cultures, the specific xylose-consumption rate had increased by 75% to 1.7 g xylose g(-1) biomass h(-1) . After storage of samples from both selection experiments at -80 °C and cultivation without acetic acid, they failed to grow on xylose at pH 4 in the presence of 5 g L(-1) acetic acid. Characterization in chemostat cultures with linear acetic acid gradients demonstrated an acetate-inducible acetic acid tolerance in samples from the continuous selection protocol.

  13. Responses of Plasma Acetate Metabolism to Hop (Humulus lupulus L. in Sheep

    Directory of Open Access Journals (Sweden)

    Mohammad Al-Mamun, Kunio Goto, Sota Chiba, Hiroaki Sano

    2009-01-01

    Full Text Available An isotope dilution method using [1-13C]sodium (Na acetate was conducted to determine the effect of feeding hop (Humulus lupulus L. residues on plasma acetate metabolism in six adult crossbred sheep. The sheep were fed 63 g/kg BW0.75/d of either mixed hay (MH-diet of orchardgrass (Dactylis glomerata L. and reed canarygrass (Phalaris arundinacea L. at a 60:40 ratio or MH-diet and hop-residues (Hop-diet at 85:15 ratio with a crossover design for each of 3 week period. The isotope dilution method using single injection of [1-13C]Na acetate was performed thrice; before feeding (BF, 2 h after feeding (2F and 4 h after feeding (4F, on the 21st day of each dietary treatment. Plasma acetate concentration tended to increase (P= 0.06 and turnover rate was numerically higher (P= 0.16 for MH-diet than Hop-diet. Plasma glucose, NEFA, VFA and lactic acid concentrations were similar between dietary treatments. In both the diets, although plasma concentration of acetate did not change, turnover rate increased significantly (P= 0.02 2F than BF. Hop-residues did not show any negative impacts on acetate metabolism as well as physiology of animals in the present experimental conditions, hence thereby it could be used as an alternative to MH-diet for rearing sheep.

  14. PVP/PEG/Carrageenan/Silver acetate hydrogels by {gamma}-ray

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Youn Mook; Youn, Young; Gwon, Hui Jeong; Park, Jong Seok; Nho, Young Chang [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2010-03-15

    In recent day, there is much interest in the biocidal activity of silver since silver is known to be safe and effective as disinifectant and biocidal material against coliforms and viruses. In this study, hydrogels containing silver acetate as antibacterial agent have been prepared using gamma rays irradiation. The hydrogels are composed of poly(vinyl pyrrolidone) (PVP), poly(ethylene glycol) (PEG), carrageenan and silver acetate. The concentration of solution was 9 wt%. The ratio of PVP: PEG: carrageenan was 6:1:2. The concentration of the silver acetate were 0,0.01, 0.03, 0.05 and 0.07% and Gamma irradiation dose was 25 kGy. The Gamma irradiation dose in hydrogels with 0.01% silver acetate were 20 kGy, 35 kGy, 50 kGy, 65 kGy, and 80 kGy. The results showed that 0.01% silver acetate concentration of hydrogels by 25 kGy irradiation dose showed the highest antibacterial activity against E. coli and Staphylococcus aureus. Moreover, antibacterial activity of various Gamma irradiation dose in hydrogels treated 0.01% silver acetate showed highest 35 kGy irradiation dose against Staphylococcus aureus.

  15. The acetates of p-nitrophenyl alpha-L-arabinofuranoside--regioselective preparation by action of lipases.

    Science.gov (United States)

    Mastihubová, Mária; Szemesová, Jana; Biely, Peter

    2006-03-15

    All possible di-O-acetates and mono-O-acetates of p-nitrophenyl alpha-L-arabinofuranoside were prepared by chemoenzymatic way using lipases. The 2,3-di-O-acetate was obtained in 90% yield by deacetylation of the primary acetyl group of per-O-acetylated p-nitrophenyl alpha-L-arabinofuranoside by Candida cylindracea lipase (CCL) or Candida rugosa lipase (LAY). The 2,5- and 3,5-di-O-acetates were obtained by acetylation of p-nitrophenyl alpha-L-arabinofuranoside by Pseudomonas cepacia lipase (LPS-30) in organic solvents. The 5-O-acetate was regioselectively synthesised in 95% yield by acetylation of p-nitrophenyl alpha-L-arabinofuranoside catalysed by porcine pancreas lipase. Finally, the 2- and 3-O-acetates of p-nitrophenyl alpha-L-arabinofuranoside were obtained in two steps. The enzymatic di-O-acetylation of p-nitrophenyl alpha-L-arabinofuranoside by LPS-30 was followed by enzymatic hydrolysis of the primary acetyl group by CCL or LAY.

  16. A comparison of roxatidine acetate and ranitidine in duodenal ulcer healing.

    Science.gov (United States)

    Hüttemann, W

    1988-01-01

    A randomised double-blind study was conducted to compare the efficacy of roxatidine acetate 75 mg twice daily with ranitidine 150 mg twice daily in 308 patients with endoscopically confirmed uncomplicated duodenal ulcers. After 6 weeks of treatment ulcer healing was found in 93.5% of the roxatidine acetate group and 89.2% of the ranitidine group, with no significant differences between treatment groups. The relief of day and night-time epigastric pain assessed at clinic visits or on diary cards by patients was comparable for both treatment groups, as was the consumption of antacid tablets for relief of symptoms of dyspepsia. There were no significant differences in the healing rates of smokers and non-smokers for either roxatidine acetate or ranitidine treatment, and no clinically significant alterations in laboratory values. Eight patients in the roxatidine acetate group and 1 in the ranitidine group complained of mild side effects, which included diarrhoea, constipation and headache. One patient on roxatidine acetate withdrew from treatment because of a mild skin rash. The results confirm that roxatidine acetate is a safe and effective treatment for duodenal ulcer disease.

  17. Inflammatory myopathy and severe rhabdomyolysis induced by leuprolide acetate therapy for prostate cancer: a case report

    Directory of Open Access Journals (Sweden)

    Rohacek Martin

    2011-08-01

    Full Text Available Abstract Introduction Leuprolide acetate is a synthetic analog of gonadotropin-releasing hormone used for the treatment of prostate cancer. Its side effects are hot flashes, nausea, and fatigue. We report a case of a patient with proximal inflammatory myopathy accompanied by severe rhabdomyolysis and renal failure following the second application of leuprolide acetate. Drug withdrawal and steroid therapy resulted in remission within six weeks of the diagnosis. To the best of our knowledge, our case report describes the second case of leuprolide acetate-induced inflammatory myopathy and the first case of severe leuprolide acetate-induced rhabdomyolysis and renal failure in the literature. Case presentation A 64-year-old Swiss Caucasian man was admitted to the hospital because of progressive proximal muscle weakness, dyspnea, and oliguria. He had been treated twice with leuprolide acetate in monthly doses. We performed a muscle biopsy, which excluded other causes of myopathy. The patient's renal failure and rhabdomyolysis were treated with rehydration and steroid therapy. Conclusion The aim of our case report is to highlight the rare but severe side effects associated with leuprolide acetate therapy used to treat patients with inflammatory myopathy: severe rhabdomyolysis and renal failure.

  18. Photorespiration participates in the assimilation of acetate in Chlorella sorokiniana under high light.

    Science.gov (United States)

    Xie, Xiujun; Huang, Aiyou; Gu, Wenhui; Zang, Zhengrong; Pan, Guanghua; Gao, Shan; He, Linwen; Zhang, Baoyu; Niu, Jianfeng; Lin, Apeng; Wang, Guangce

    2016-02-01

    The development of microalgae on an industrial scale largely depends on the economic feasibility of mass production. High light induces productive suspensions during cultivation in a tubular photobioreactor. Herein, we report that high light, which inhibited the growth of Chlorella sorokiniana under autotrophic conditions, enhanced the growth of this alga in the presence of acetate. We compared pigments, proteomics and the metabolic flux ratio in C. sorokiniana cultivated under high light (HL) and under low light (LL) in the presence of acetate. Our results showed that high light induced the synthesis of xanthophyll and suppressed the synthesis of chlorophylls. Acetate in the medium was exhausted much more rapidly in HL than in LL. The data obtained from LC-MS/MS indicated that high light enhanced photorespiration, the Calvin cycle and the glyoxylate cycle of mixotrophic C. sorokiniana. The results of metabolic flux ratio analysis showed that the majority of the assimilated carbon derived from supplemented acetate, and photorespiratory glyoxylate could enter the glyoxylate cycle. Based on these data, we conclude that photorespiration provides glyoxylate to speed up the glyoxylate cycle, and releases acetate-derived CO2 for the Calvin cycle. Thus, photorespiration connects the glyoxylate cycle and the Calvin cycle, and participates in the assimilation of supplemented acetate in C. sorokiniana under high light.

  19. Clomazone selectivity in cotton seeds treated with dietholate and zinc acetate

    Directory of Open Access Journals (Sweden)

    Miriam Hiroko Inoue

    2014-12-01

    Full Text Available The objective of this study objective was to evaluate the selectivity of pre-emergence applications the herbicide clomazone cotton seeds treated with dietholate and zinc acetate. The 4 x 2 factorial arrangement was adopted (4 seed treatment methods and 2 clomazone dosages, distributed in a randomized block design with 4 repetitions. In treatments where dietholate and zinc acetate were applied, rates of 0.4 kg ha-1 and 8 ml per kg of seeds were used respectively. The clomazone rates used refer to 0.8 and 1.0 kg ha- 1. The cotton cultivar used was the Fiber Max 966 LL. Independent of treatment, all seeds were treated with tiametoxam insecticide and fludioxonil + metalaxyl-M fungicide at rates of 2.24 and 0.08 + 0.03 g per kg of seed, respectively, to control pests early and limit losses caused by pathogens in germination and seedling emergence. Dietholate and zinc acetate treatment had greater initial effect on cotton plants at 21, 30 and 45 days after application. In phytointoxication symptoms were observed for treatment with dietholate and zinc acetate during the evaluation periods. Seeds treated with dietholate, dietholate and zinc acetate or zinc acetate alone provided a higher number of bolls and seed cotton production compared to the control.

  20. Tolerance to acetic acid is improved by mutations of the TATA-binding protein gene.

    Science.gov (United States)

    An, Jieun; Kwon, Hyeji; Kim, Eunjung; Lee, Young Mi; Ko, Hyeok Jin; Park, Hongjae; Choi, In-Geol; Kim, Sooah; Kim, Kyoung Heon; Kim, Wankee; Choi, Wonja

    2015-03-01

    Screening a library of overexpressing mutant alleles of the TATA-binding gene SPT15 yielded two Saccharomyces cerevisiae strains (MRRC 3252 and 3253) with enhanced tolerance to acetic acid. They were also tolerant to propionic acid and hydrogen peroxide. Transcriptome profile analysis identified 58 upregulated genes and 106 downregulated genes in MRRC 3252. Stress- and protein synthesis-related transcription factors were predominantly enriched in the upregulated and downregulated genes respectively. Eight deletion mutants for some of the highly downregulated genes were acetic acid-tolerant. The level of intracellular reactive oxygen species was considerably lessened in MRRC 3252 and 3253 upon exposure to acetic acid. Metabolome profile analysis revealed that intracellular concentrations of 5 and 102 metabolites were increased and decreased, respectively, in MRRC 3252, featuring a large increase of urea and a significant decrease of amino acids. The dur1/2Δmutant, in which the urea degradation gene DUR1/2 is deleted, displayed enhanced tolerance to acetic acid. Enhanced tolerance to acetic acid was also observed on the medium containing a low concentration of amino acids. Taken together, this study identified two SPT15 alleles, nine gene deletions and low concentration of amino acids in the medium that confer enhanced tolerance to acetic acid.

  1. Thermal decarboxylation of acetic acid: Implications for origin of natural gas

    Science.gov (United States)

    Kharaka, Y.K.; Carothers, W.W.; Rosenbauer, R.J.

    1983-01-01

    Laboratory experiments on the thermal decarboxylation of solutions of acetic acid at 200??C and 300??C were carried out in hydrothermal equipment allowing for on-line sampling of both the gas and liquid phases for chemical and stable-carbon-isotope analyses. The solutions had ambient pH values between 2.5 and 7.1; pH values and the concentrations of the various acetate species at the conditions of the experiments were computed using a chemical model. Results show that the concentrations of acetic acid, and not total acetate in solution, control the reaction rates which follow a first order equation based on decreasing concentrations of acetic acid with time. The decarboxylation rates at 200??C (1.81 ?? 10-8 per second) and 300??C (8.17 ?? 10-8 per second) and the extrapolated rates at lower temperatures are relatively high. The activation energy of decarboxylation is only 8.1 kcal/mole. These high decarboxylation rates, together with the distribution of short-chained aliphatic acid anions in formation waters, support the hypothesis that acid anions are precursors for an important portion of natural gas. Results of the ??13C values of CO2, CH4, and total acetate show a reasonably constant fractionation factor of about 20 permil between CO2 and CH4 at 300??C. The ??13C values of CO2 and CH4 are initially low and become higher as decarboxylation increases. ?? 1983.

  2. Combination effect of pH and acetate on enzymatic cellulose hydrolysis

    Institute of Scientific and Technical Information of China (English)

    ROMSAIYUD Angsana; SONGKASIRI Warinthom; NOPHARATANA Annop; CHAIPRASERT Pawinee

    2009-01-01

    The productivity and efficiency of cellulase are significant in cellulose hydrolysis. With the accumulation of volatile fatty acids (VFAs), the pH value in anaerobic digestion system is reduced. Therefore, this study will find out how the pH and the amount of acetate influence the enzymatic hydrolysis of cellulose. The effects of pH and acetate on cellulase produced from Bacillus coagulans were studied at various pH 5-8, and acetate concentrations (0-60 mmol/L). A batch kinetic model for enzymatic cellulose hydrolysis was constructed from experimental data and performed. The base hypothesis was as follows: the rates of enzymatic cellulose hydrolysis rely on pH and acetate concentration. The results showed that the suitable pH range for cellulase production and cellulose hydrolysis (represents efficiency of cellulase) was 2.6-7.5, and 5.3-8.3, respectively. Moreover, acetate in the culture medium had an effect on cellulase production (K1= 49.50 mmol/L, n=1.7) less than cellulose hydrolysis (K1=37.85 mmol/L, n=2.0). The results indicated that both the pH of suspension and acidogenic products influence the enzymatic hydrolysis of cellulose in an anaerobic environment. To enhance the cellulose hydrolysis rate, the accumulated acetate concentration should be lower than 25 mmol/L, and pH should be maintained at 7.

  3. Applicability of the SQM force field method to the vibrational spectra of sodium acetate.

    Science.gov (United States)

    Keresztury, Gabor; Istvan, Krisztina; Sundius, Tom

    2005-09-08

    The applicability of the scaled quantum mechanical force field (SQM FF) method to the prediction of the vibrational spectra of a charged molecule has been studied by the example of the acetate ion (CH3CO2-) in sodium acetate for which an efficient empirical valence force field (SVFF) based on observed IR spectra of six isotopomers of sodium acetate is available in the literature. Standard SQM FF calculations done on a free acetate ion at the B3LYP/6-31G level failed to give an acceptable estimation of even the most characteristic features of the observed spectra, which can be exemplified by the gross overestimation of the frequency separation of the nu(a)CO2- and nu(s)CO2- vibrations. In search for a better description, SQM calculations were done for three simple structural models of sodium acetate, testing different QM methods. The results indicate that in addition to taking into account the dielectric field effect of the surrounding medium, incorporation of a Na+ counterion is necessary to achieve a realistic simulation of the IR and Raman spectra. Satisfactory results were obtained with a bidentate Na-acetate complex by the SQM method coupled with a continuum model at the B3LYP/6-31+G level, whereas the use of the Onsager-type spherical cavity model and the polarizable continuum model (PCM) were found preferable over SCI-PCM.

  4. A vinyl acetate sensor based on cataluminescence on MgO nanoparticles.

    Science.gov (United States)

    Wu, Chen Chou; Cao, Xiaoan; Wen, Qiang; Wang, Zehua; Gao, Qianqian; Zhu, Huichang

    2009-10-15

    A novel cataluminescence (CTL) sensor using nanosized MgO as the sensing material for determination of the trace of vinyl acetate in air was proposed in the present study. Eight catalysts were examined and the results showed that the CTL intensity on MgO nanoparticles was the strongest. Under the optimized conditions, the linear range of the CTL intensity versus the concentration of vinyl acetate vapor was 2-2000 ppm with a detection limit of 1.0 ppm (3sigma) and a relative standard deviation (R.S.D.) of 1.18% for five times determination of 1000 ppm vinyl acetate. There were no CTL emissions when foreign substances, including ammonia, benzene, acetic acid, formaldehyde and ethyl acetate, passed through the sensor. CTL emissions were detected for methanol, ethanol and acetaldehyde at levels around 5.5%, 10.1% and 13.4% compared with the responsed vinyl acetate. The sensor had a long lifetime more than 100 h.

  5. Effect of manganese ions on ethanol fermentation by xylose isomerase expressing Saccharomyces cerevisiae under acetic acid stress.

    Science.gov (United States)

    Ko, Ja Kyong; Um, Youngsoon; Lee, Sun-Mi

    2016-12-01

    The efficient fermentation of lignocellulosic hydrolysates in the presence of inhibitors is highly desirable for bioethanol production. Among the inhibitors, acetic acid released during the pretreatment of lignocellulose negatively affects the fermentation performance of biofuel producing organisms. In this study, we evaluated the inhibitory effects of acetic acid on glucose and xylose fermentation by a high performance engineered strain of xylose utilizing Saccharomyces cerevisiae, SXA-R2P-E, harboring a xylose isomerase based pathway. The presence of acetic acid severely decreased the xylose fermentation performance of this strain. However, the acetic acid stress was alleviated by metal ion supplementation resulting in a 52% increased ethanol production rate under 2g/L of acetic acid stress. This study shows the inhibitory effect of acetic acid on an engineered isomerase-based xylose utilizing strain and suggests a simple but effective method to improve the co-fermentation performance under acetic acid stress for efficient bioethanol production.

  6. The fraction of cells that resume growth after acetic acid addition is a strain-dependent parameter of acetic acid tolerance in Saccharomyces cerevisiae.

    Science.gov (United States)

    Swinnen, Steve; Fernández-Niño, Miguel; González-Ramos, Daniel; van Maris, Antonius J A; Nevoigt, Elke

    2014-06-01

    High acetic acid tolerance of Saccharomyces cerevisiae is a relevant phenotype in industrial biotechnology when using lignocellulosic hydrolysates as feedstock. A screening of 38 S. cerevisiae strains for tolerance to acetic acid revealed considerable differences, particularly with regard to the duration of the latency phase. To understand how this phenotype is quantitatively manifested, four strains exhibiting significant differences were studied in more detail. Our data show that the duration of the latency phase is primarily determined by the fraction of cells within the population that resume growth. Only this fraction contributed to the exponential growth observed after the latency phase, while all other cells persisted in a viable but non-proliferating state. A remarkable variation in the size of the fraction was observed among the tested strains differing by several orders of magnitude. In fact, only 11 out of 10(7)  cells of the industrial bioethanol production strain Ethanol Red resumed growth after exposure to 157 mM acetic acid at pH 4.5, while this fraction was 3.6 × 10(6) (out of 10(7)  cells) in the highly acetic acid tolerant isolate ATCC 96581. These strain-specific differences are genetically determined and represent a valuable starting point to identify genetic targets for future strain improvement.

  7. Synthesis of Highly Polymerized Water-soluble Cellulose Acetate by the Side Reaction in Carboxylate Ionic Liquid 1-ethyl-3-methylimidazolium Acetate

    Science.gov (United States)

    Pang, Jinhui; Liu, Xin; Yang, Jun; Lu, Fachuang; Wang, Bo; Xu, Feng; Ma, Mingguo; Zhang, Xueming

    2016-09-01

    In the present study, we describe a novel one-step method to prepare water-soluble cellulose acetate (WSCA) with higher degree of polymerization values (DP = 650–680) by in situ activation of carboxyl group in ionic liquid. First of all, cellulose was dissolved in 1-ethyl-3-methylimidazolium acetate (EmimAc) and reacted with dichloroacetyl chloride (Cl2AcCl) in order to make cellulose dichloroacetate. Under various conditions, a series of water soluble products were produced. Elemental analysis and NMR results confirmed that they were cellulose acetate with DS (degree of substitution) values in the range from 0.30 to 0.63. NMR studies demonstrated that Cl2AcCl reacted with acetate anion of EmimAc producing a mixed anhydride that acetylated cellulose. Other acylating reagents such as benzoyl chloride, chloroacetyl chloride can also work similarly. 2D NMR characterization suggested that 6-mono-O-acetyl moiety, 3,6-di-O-acetylcellulose and 2,6-di-O-acetyl cellulose were all synthesized and the reactivity of hydroxyl groups in anhydro-glucose units was in the order C-6>C-3>C-2. This work provides an alternative way to make WSCA, meanwhile, also services as a reminder that the activity of EmimAc toward carbohydrate as acylating reagents could be a problem, because the expected acylated products may not be resulted and recycling of this ionic liquid could also be difficult.

  8. Anion release and uptake kinetics: structural changes of layered 2-dimensional ZnNiHN upon uptake of acetate and chlorinated acetate anions.

    Science.gov (United States)

    Machingauta, Cleopas; Hossenlopp, Jeanne M

    2013-12-01

    X-ray diffraction and UV-vis spectroscopy were used for the investigation of ion exchange reaction kinetics of nitrates with acetate (Ac), chloro acetate (ClAc), dichloro acetate (dClAc) and trichloro acetate (tClAc) anions, using zinc nickel hydroxy nitrate (ZnNiHN) as the exchange precursor. The exchange reactions conducted at 24, 30, 40 and 50°C revealed that rate constants were inversely related to the calculated anion electronic spatial extent (ESE), while a direct relationship between rate constants and the average oxygen charges was observed. Temporal solid phase structural transformations were shown to be affected by the nature of the guest anions. The amount of nitrates released into solution has been shown to decrease as the guest anions became more chlorinated. Use of isoconversional approach revealed that activation energies changed significantly with α during dClAc intercalation than for the other anions. The topotactic intercalation of the guest anions, except dClAc, followed the Avrami-Erofe'ev kinetic model for the entire reaction progress.

  9. Synthesis of Highly Polymerized Water-soluble Cellulose Acetate by the Side Reaction in Carboxylate Ionic Liquid 1-ethyl-3-methylimidazolium Acetate

    Science.gov (United States)

    Pang, Jinhui; Liu, Xin; Yang, Jun; Lu, Fachuang; Wang, Bo; Xu, Feng; Ma, Mingguo; Zhang, Xueming

    2016-01-01

    In the present study, we describe a novel one-step method to prepare water-soluble cellulose acetate (WSCA) with higher degree of polymerization values (DP = 650–680) by in situ activation of carboxyl group in ionic liquid. First of all, cellulose was dissolved in 1-ethyl-3-methylimidazolium acetate (EmimAc) and reacted with dichloroacetyl chloride (Cl2AcCl) in order to make cellulose dichloroacetate. Under various conditions, a series of water soluble products were produced. Elemental analysis and NMR results confirmed that they were cellulose acetate with DS (degree of substitution) values in the range from 0.30 to 0.63. NMR studies demonstrated that Cl2AcCl reacted with acetate anion of EmimAc producing a mixed anhydride that acetylated cellulose. Other acylating reagents such as benzoyl chloride, chloroacetyl chloride can also work similarly. 2D NMR characterization suggested that 6-mono-O-acetyl moiety, 3,6-di-O-acetylcellulose and 2,6-di-O-acetyl cellulose were all synthesized and the reactivity of hydroxyl groups in anhydro-glucose units was in the order C-6>C-3>C-2. This work provides an alternative way to make WSCA, meanwhile, also services as a reminder that the activity of EmimAc toward carbohydrate as acylating reagents could be a problem, because the expected acylated products may not be resulted and recycling of this ionic liquid could also be difficult. PMID:27644545

  10. Probing the Methyl Torsional Barriers of the E and Z Isomers of Butadienyl Acetate by Microwave Spectroscopy

    Science.gov (United States)

    Jabri, Atef; Nguyen, Ha Vinh Lam; Kleiner, Isabelle; Van, Vinh; Stahl, Wolfgang

    2016-06-01

    The Fourier transform microwave spectra of the E and the Z isomer of butadienyl acetate have been measured in the frequency range from 2 to 26.5 GHz under molecular beam conditions. The most stable conformer of each isomer, in which all heavy atoms are located in a symmetry plane, was identified after analyzing the spectrum by comparison with results from quantum chemical calculations. The barrier to internal rotation of the acetyl methyl group was found to be 149.1822(20) cm-1 and 150.2128(48) cm-1 for the E and the Z isomer, respectively, which are similar to that of vinyl acetate. A comparison between two theoretical approaches treating internal rotations, the rho axis method (using the program BELGI-Cs) and combined axis method (using the program XIAM), is also performed. Since several years we study the barriers to internal rotation of the acetyl methyl group in acetates, CH3-COOR. Currently, we assume that all acetates can be divided into three classes. Class I contains α,β saturated acetates, where the torsional barrier is always close to 100 cm-1. Examples are a series of alkyl acetates such as methyl acetate and ethyl acetate. Class II contains α,β-unsaturated acetates where the C=C double bond is located in the COO plane. This is the case of vinyl acetate and butadienyl acetate. Finally, in class III with isopropenyl acetate and phenyl acetate as two representatives, α,β-unsaturated acetates, in which the double bond is not located in the COO plane, are collected. There, we observed a barrier height around 135 cm-1. This observation will be discussed in details. B. Velino, A. Maris, S. Melandri, W. Caminati, J. Mol. Spectrosc. 2009, 256, 228 H. V. L. Nguyen, A. Jabri, V. Van, and W. Stahl, J. Phys. Chem. A, 2014, 118, 12130.

  11. Performance of dairy cows fed high levels of acetic acid or ethanol.

    Science.gov (United States)

    Daniel, J L P; Amaral, R C; Sá Neto, A; Cabezas-Garcia, E H; Bispo, A W; Zopollatto, M; Cardoso, T L; Spoto, M H F; Santos, F A P; Nussio, L G

    2013-01-01

    Ethanol and acetic acid are common end products from silages. The main objective of this study was to determine whether high concentrations of ethanol or acetic acid in total mixed ration would affect performance in dairy cows. Thirty mid-lactation Holstein cows were grouped in 10 blocks and fed one of the following diets for 7 wk: (1) control (33% Bermuda hay + 67% concentrates), (2) ethanol [control diet + 5% ethanol, dry matter (DM) basis], or (3) acetic acid (control diet + 5% acetic acid, DM basis). Ethanol and acetic acid were diluted in water (1:2) and sprayed onto total mixed rations twice daily before feeding. An equal amount of water was mixed with the control ration. To adapt animals to these treatments, cows were fed only half of the treatment dose during the first week of study. Cows fed ethanol yielded more milk (37.9 kg/d) than those fed the control (35.8 kg/d) or acetic acid (35.3 kg/d) diets, mainly due to the higher DM intake (DMI; 23.7, 22.2, and 21.6 kg/d, respectively). The significant diet × week interaction for DMI, mainly during wk 2 and 3 (when acetic acid reached the full dose), was related to the decrease in DMI observed for the acetic acid treatment. There was a diet × week interaction in excretion of milk energy per DMI during wk 2 and 3, due to cows fed acetic acid sustained milk yield despite lower DMI. Energy efficiency was similar across diets. Blood metabolites (glucose, insulin, nonesterified fatty acids, ethanol, and γ-glutamyl transferase activity) and sensory characteristics of milk were not affected by these treatments. Animal performance suggested similar energy value for the diet containing ethanol compared with other diets. Rumen conversion of ethanol to acetate and a concomitant increase in methane production might be a plausible explanation for the deviation of the predicted energy value based on the heat of combustion. Therefore, the loss of volatile compounds during the drying process in the laboratory should be

  12. Interaction of dispersed polyvynil acetate with silicate in finishing materials

    Directory of Open Access Journals (Sweden)

    Runova, R. F.

    1996-12-01

    Full Text Available This article focuses on the processes of interaction between calcium silicate hydrates and dispersed polyvinyl acetate in tight films with the aim of developing compounds meant for restoration and finishing works. The basis of this development relies on the concept concerning the determining role of the crystal-chemical factor of the silicate phase in the formation of organic-mineral compounds of increased durability. The characteristics of dispersed calcium silicate hydrates are portrayed. The preparation conditions, accounting for the synthesis of the product of submicrocrystalline structure, conforming with the stoichiometry CaO∙SiO2 =0.8-2.0 have been determined. The interaction has been studied for compounds achieved by mixing ingredients in a rapid whirling mixer, and subjected to hardening at T=20+2 T. With the aid of XRD, DTA and Infra-Red Spectrometry methods the formation process of the sophisticated polymer silicate phase in the material was observed for a period of 90 days. The properties of the film were investigated and its high resistance against the influence of external factors was established. On this basis a conclusion concerning the quite high effectiveness of substituting portland cement with dispersed calcium silicate hydrate in polymer cement compounds has been made. White colour and other various special properties determine the suitability for repair and finishing works on facades of buildings.

    Este artículo está orientado a estudiar los procesos de interacción entre los silicatos cálcicos hidratados y el acetato de polivinilo disperso en capas impermeables, con el objeto de desarrollar compuestos destinados para la restauración. El fundamento de estos estudios es determinar el papel que los factores cristaloquímicos de las fases silicato tienen en la formación de compuestos órganominerales de elevada durabilidad. Se han descrito las características de los silicatos cálcicos hidratados

  13. Effects of hydrogen and acetate on benzene mineralisation under sulphate-reducing conditions.

    Science.gov (United States)

    Rakoczy, Jana; Schleinitz, Kathleen M; Müller, Nicolai; Richnow, Hans H; Vogt, Carsten

    2011-08-01

    Syntrophic mineralisation of benzene, as recently proposed for a sulphate-reducing enrichment culture, was tested in product inhibition experiments with acetate and hydrogen, both putative intermediates of anaerobic benzene fermentation. Using [(13)C(6)]-benzene enabled tracking the inhibition of benzene mineralisation sensitively by analysis of (13)CO(2). In noninhibited cultures, hydrogen was detected at partial pressures of 2.4 × 10(-6) ± 1.5 × 10(-6) atm. Acetate was detected at concentrations of 17 ± 2 μM. Spiking with 0.1 atm hydrogen produced a transient inhibitory effect on (13)CO(2) formation. In cultures spiked with higher amounts of hydrogen, benzene mineralisation did not restart after hydrogen consumption, possibly due to the toxic effects of the sulphide produced. An inhibitory effect was also observed when acetate was added to the cultures (0.3, 3.5 and 30 mM). Benzene mineralisation resumed after acetate was degraded to concentrations found in noninhibited cultures, indicating that acetate is another key intermediate in anaerobic benzene mineralisation. Although benzene mineralisation by a single sulphate reducer cannot be ruled out, our results strongly point to an involvement of syntrophic interactions in the process. Thermodynamic calculations revealed that, under in situ conditions, benzene fermentation to hydrogen and acetate yielded a free energy change of ΔG'=-83.1 ± 5.6 kJ mol(-1). Benzene mineralisation ceased when ΔG' values declined below -61.3 ± 5.3 kJ mol(-1) in the presence of acetate, indicating that ATP-consuming reactions are involved in the pathway.

  14. Genome-guided analysis of physiological and morphological traits of the fermentative acetate oxidizer Thermacetogenium phaeum

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    Oehler Dirk

    2012-12-01

    Full Text Available Abstract Background Thermacetogenium phaeum is a thermophilic strictly anaerobic bacterium oxidizing acetate to CO2 in syntrophic association with a methanogenic partner. It can also grow in pure culture, e.g., by fermentation of methanol to acetate. The key enzymes of homoacetate fermentation (Wood-Ljungdahl pathway are used both in acetate oxidation and acetate formation. The obvious reversibility of this pathway in this organism is of specific interest since syntrophic acetate oxidation operates close to the energetic limitations of microbial life. Results The genome of Th. phaeum is organized on a single circular chromosome and has a total size of 2,939,057 bp. It comprises 3.215 open reading frames of which 75% could be assigned to a gene function. The G+C content is 53.88 mol%. Many CRISPR sequences were found, indicating heavy phage attack in the past. A complete gene set for a phage was found in the genome, and indications of phage action could also be observed in culture. The genome contained all genes required for CO2 reduction through the Wood-Ljungdahl pathway, including two formyl tetrahydrofolate ligases, three carbon monoxide dehydrogenases, one formate hydrogenlyase complex, three further formate dehydrogenases, and three further hydrogenases. The bacterium contains a menaquinone MQ-7. No indications of cytochromes or Rnf complexes could be found in the genome. Conclusions The information obtained from the genome sequence indicates that Th. phaeum differs basically from the three homoacetogenic bacteria sequenced so far, i.e., the sodium ion-dependent Acetobacterium woodii, the ethanol-producing Clostridium ljungdahlii, and the cytochrome-containing Moorella thermoacetica. The specific enzyme outfit of Th. phaeum obviously allows ATP formation both in acetate formation and acetate oxidation.

  15. The fate of acetic acid during glucose co-metabolism by the spoilage yeast Zygosaccharomyces bailii.

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    Fernando Rodrigues

    Full Text Available Zygosaccharomyces bailii is one of the most widely represented spoilage yeast species, being able to metabolise acetic acid in the presence of glucose. To clarify whether simultaneous utilisation of the two substrates affects growth efficiency, we examined growth in single- and mixed-substrate cultures with glucose and acetic acid. Our findings indicate that the biomass yield in the first phase of growth is the result of the weighted sum of the respective biomass yields on single-substrate medium, supporting the conclusion that biomass yield on each substrate is not affected by the presence of the other at pH 3.0 and 5.0, at least for the substrate concentrations examined. In vivo(13C-NMR spectroscopy studies showed that the gluconeogenic pathway is not operational and that [2-(13C]acetate is metabolised via the Krebs cycle leading to the production of glutamate labelled on C(2, C(3 and C(4. The incorporation of [U-(14C]acetate in the cellular constituents resulted mainly in the labelling of the protein and lipid pools 51.5% and 31.5%, respectively. Overall, our data establish that glucose is metabolised primarily through the glycolytic pathway, and acetic acid is used as an additional source of acetyl-CoA both for lipid synthesis and the Krebs cycle. This study provides useful clues for the design of new strategies aimed at overcoming yeast spoilage in acidic, sugar-containing food environments. Moreover, the elucidation of the molecular basis underlying the resistance phenotype of Z. bailii to acetic acid will have a potential impact on the improvement of the performance of S. cerevisiae industrial strains often exposed to acetic acid stress conditions, such as in wine and bioethanol production.

  16. Enzymatic synthesis of isoamyl acetate using immobilized lipase from Rhizomucor miehei.

    Science.gov (United States)

    Hari Krishna, S; Divakar, S; Prapulla, S G; Karanth, N G

    2001-05-18

    The effects of important reaction parameters for enhancing isoamyl acetate formation through lipase-catalyzed esterification of isoamyl alcohol were investigated in this study. Increase in substrate (acid) concentration led to decrease in conversions. A critical enzyme concentration of 3 g l(-1) was detected for a substrate concentration of 0.06 M (each of alcohol and acid). Solvents with partition coefficient higher than 1000 (log P>3.0) supported enzyme activity to give high conversions. Acetic acid at higher concentrations could not be esterified easily probably owing to its role in lowering the microaqueous pH of the enzyme. Extraneous water/buffer addition decreased the isoamyl acetate yields slightly ( approximately 10%) at 0.005-0.01% v/v of the reaction mixture and drastically (>40%) at above 0.01% v/v. Buffer saturation of the organic solvent employed improved esterification (upto two-fold), particularly at moderately higher substrate concentrations (>0.18 M). Employing acetic anhydride instead of acetic acid resulted in a two-fold increase in the yields (at 0.25 M substrate). Use of excess nucleophile (alcohol) concentration by increasing the alcohol/acid molar ratio resulted in higher conversions in shorter duration (upto eight-fold even at 1.5 M acetic acid). Yields above 80% were achieved with substrate concentrations as high as 1.5 M and more than 150 g l(-1) isoamyl acetate concentrations were obtained employing a relatively low enzyme concentration of 10 g l(-1). The operational stability of lipase was also observed to be reasonably high enabling ten reuses of the biocatalyst.

  17. ELDOR study of methyl radical production at 77 K in irradiated acetate powders as a function of metal cation

    Energy Technology Data Exchange (ETDEWEB)

    Mottley, C.; Kispert, L.D.; Wang, P.S.

    1976-08-12

    Paramagnetic relaxation characteristics of the methyl radical at 77/sup 0/K in irradiated powders of magnesium acetate tetrahydrate, potassium acetate, sodium acetate trihydrate, calcium acetate monohydrate, zinc acetate dihydrate, and lithium acetate dihydrate were measured by power saturation techniques and ELDOR spectroscopy. For magnesium acetate tetrahydrate the characteristic relaxation time (T/sub 1e/T/sub 2e/)/sup /sup 1///sub 2// for the methyl radical is relatively constant with radiation dose at low doses and decreases at higher doses. For sodium acetate trihydrate the relaxation time decreases even at low dose. ELDOR measurements of the ratio of the intermolecular relaxation time (T/sub po/) between methyl radicals to the spin--lattice relaxation time (T/sub 1e/) shows an increase from 0.05 for magnesium acetate trihydrate to greater than 1 for sodium acetate trihydrate. In addition, the field-swept ELDOR reduction factors for the m/sub I/ = -/sup 3///sub 2/ ESR line of the methyl radical utilizing 100-kHz field modulation decreases from 73 percent in irradiated magnesium acetate tetrahydrate to 2 percent in irradiated calcium acetate monohydrate. These features suggest that the radiation produced methyl radicals are trapped in clusters in acetates at low dose forming a nonuniform spatial distribution that is dependent on the cation and decreases in the approximate order Mg/sup 2 +/ greater than K/sup +/ greater than Na/sup +/ greater than Ca/sup 2 +/. No estimate of the amount of clustering in the irradiated Zn/sup 2 +/ and Li/sup +/ salts could be made due to the long T/sub 1e/'s exhibited by the methyl radical.

  18. Reproductive efficiency of rats whose mothers treated with lead acetate during lactation: role of vitamin E

    Directory of Open Access Journals (Sweden)

    W. H. Yousif

    2010-01-01

    Full Text Available Reproductive efficiency of young male and female rats yielded from mothers treated with lead acetate (10 mg/kg B.W and vitamin E as an antioxidant (500 mg/kg during lactation period was studied. 27 pregnant albino rats aged 4-5 months divided into 3 groups, the first group given 0.2 ml distilled water through oral intubations (control. The second group given lead acetate (10 mg/kg B.W, while the 3rd group given lead acetate (10 mg/kg B.W with vitamin E (500 mg/kg B.Wt. Lead acetate treatment did not cause significant difference (P>0.05 in young male rats body, testes, epididymal (head, tail, prostate gland, seminal vesicle weights, number of epidiymal sperms count, percentage of live/dead sperms and sperms abnormalities accompanied with a significant increase (P0.05 in ovary and uterus weights. Lead acetate with vit. E cause significant decrease (P<0.05 in body, testes, epididymal (head, body weights, number of epididymal sperm count, percentage of live/dead and sperm abnormalities. Concerning young female rats treated with lead acetate and vit E showed a significant decrease (P<0.05 in body, uterus weights with a significant increase (P<0.05 in the duration of vaginal opening. Histopathological study revealed changes in the testes such as desquemination in some epithelial lining of seminiferous tubules and sertoli cells. Undevelopment of localized area of some seminiferous tubules with blood vessels congestion in both testes and ovaries with hyperemia in ovarian stroma, increase in follicular cells, decrease in corpus luteum formation, degeneration of ovarian follicles and increase in ovarian adipose tissue. This study concluded that lead acetate can be transmitted through mother milk to their pups. The dose of lead acetate (10 mg/kg B.W was enough to make bad effects on both male and female reproductive systems. Vitamin E (as an antioxidant found to have no improving effect in treatment of lead acetate disturbances on reproductive systems of

  19. Cervicovaginal fluid acetate: a metabolite marker of preterm birth in symptomatic pregnant women

    Directory of Open Access Journals (Sweden)

    Emmanuel Amabebe

    2016-10-01

    Full Text Available Changes in vaginal microbiota that are associated with preterm birth (PTB leave specific metabolite fingerprints that can be detected in the cervicovaginal fluid (CVF using metabolomics techniques. In this study we characterize and validate the CVF metabolite profile of pregnant women presenting with symptoms of threatened preterm labor (PTL by both 1H-Nuclear Magnetic Resonance spectroscopy (NMR and enzyme-based spectrophotometry. We also determine their predictive capacity for PTB, singly and in combination with current clinical screening tools – cervicovaginal fetal fibronectin (FFN and ultrasound cervical length (CL.CVF was obtained by high-vaginal swabs from 82 pregnant women with intact fetal membranes presenting between 24 and 36 weeks (wks gestation with symptoms of threatened, but not established, PTL. Dissolved CVF samples were scanned with a 400 MHz NMR spectrometer. Acetate and other metabolites were identified in the NMR spectrum, integrated for peak area, and normalized to the total spectrum integral. To confirm and validate our observations, acetate concentrations (AceConc were also determined from a randomly selected subset of the same samples (n=57, by spectrophotometric absorption of NADH using an acetic acid assay kit. CVF FFN level, transvaginal ultrasound CL, and vaginal pH were also ascertained.Acetate normalized integral and AceConc were significantly higher in the women who delivered preterm compared to their term counterparts (P=0.002 and P=0.006 respectively. The 1H-NMR-derived acetate integrals were strongly correlated with the AceConc estimated by spectrophotometry (r=0.69; P0.53 g/l, and of delivery within 2 weeks of the index assessment (acetate integral: AUC=0.77, 95% CI=0.58-0.96; AceConc: AUC=0.68, 95% CI=0.5-0.9. The combination of CVF acetate, FFN and ultrasound CL in a binary logistic regression model improved the prediction of PTB compared to the 3 markers individually. Elevated CVF acetate in women with

  20. ATP-Citrate Lyase Controls a Glucose-to-Acetate Metabolic Switch

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    Steven Zhao

    2016-10-01

    Full Text Available Mechanisms of metabolic flexibility enable cells to survive under stressful conditions and can thwart therapeutic responses. Acetyl-coenzyme A (CoA plays central roles in energy production, lipid metabolism, and epigenomic modifications. Here, we show that, upon genetic deletion of Acly, the gene coding for ATP-citrate lyase (ACLY, cells remain viable and proliferate, although at an impaired rate. In the absence of ACLY, cells upregulate ACSS2 and utilize exogenous acetate to provide acetyl-CoA for de novo lipogenesis (DNL and histone acetylation. A physiological level of acetate is sufficient for cell viability and abundant acetyl-CoA production, although histone acetylation levels remain low in ACLY-deficient cells unless supplemented with high levels of acetate. ACLY-deficient adipocytes accumulate lipid in vivo, exhibit increased acetyl-CoA and malonyl-CoA production from acetate, and display some differences in fatty acid content and synthesis. Together, these data indicate that engagement of acetate metabolism is a crucial, although partial, mechanism of compensation for ACLY deficiency.

  1. Response of anaerobes to methyl fluoride, 2-bromoethanesulfonate and hydrogen during acetate degradation

    Institute of Scientific and Technical Information of China (English)

    Liping Hao; Fan Lü; Lei Li; Liming Shao; Pinjing He

    2013-01-01

    To use the selective inhibition method for quantitative analysis of acetate metabolism in methanogenic systems,the responses of microbial communities and metabolic activities,which were involved in anaerobic degradation of acetate,to the addition of methyl fluoride (CH3F),2-bromoethanesulfonate (BES) and hydrogen were investigated in a thermophilic batch experiment.Both the methanogenic inhibitors,i.e.,CH3F and BES,showed their effectiveness on inhibiting CH4 production,whereas acetate metabolism other than acetoclastic methanogenesis was stimulated by BES,as reflected by the fluctuated acetate concentration.Syntrophic acetate oxidation was thermodynamically blocked by hydrogen (H2),while H2-utilizing reactions as hydrogenotrophic methanogencsis and homoacetogenesis were correspondingly promoted.Results of PCR-DGGE fingerprinting showed that,CH3F did not influence the microbial populations significantly.However,the BES and hydrogen notably altered the bacterial community structures and increased the diversity.BES gradually changed the methanogenic community structure by affecting the existence of different populations to different levels,whilst H2 greatly changed the abundance of different methanogenic populations,and induced growth of new species.

  2. Candida zemplinina can reduce acetic acid produced by Saccharomyces cerevisiae in sweet wine fermentations.

    Science.gov (United States)

    Rantsiou, Kalliopi; Dolci, Paola; Giacosa, Simone; Torchio, Fabrizio; Tofalo, Rosanna; Torriani, Sandra; Suzzi, Giovanna; Rolle, Luca; Cocolin, Luca

    2012-03-01

    In this study we investigated the possibility of using Candida zemplinina, as a partner of Saccharomyces cerevisiae, in mixed fermentations of must with a high sugar content, in order to reduce its acetic acid production. Thirty-five C. zemplinina strains, which were isolated from different geographic regions, were molecularly characterized, and their fermentation performances were determined. Five genetically different strains were selected for mixed fermentations with S. cerevisiae. Two types of inoculation were carried out: coinoculation and sequential inoculation. A balance between the two species was generally observed for the first 6 days, after which the levels of C. zemplinina started to decrease. Relevant differences were observed concerning the consumption of sugars, the ethanol and glycerol content, and acetic acid production, depending on which strain was used and which type of inoculation was performed. Sequential inoculation led to the reduction of about half of the acetic acid content compared to the pure S. cerevisiae fermentation, but the ethanol and glycerol amounts were also low. A coinoculation with selected combinations of S. cerevisiae and C. zemplinina resulted in a decrease of ~0.3 g of acetic acid/liter, while maintaining high ethanol and glycerol levels. This study demonstrates that mixed S. cerevisiae and C. zemplinina fermentation could be applied in sweet wine fermentation to reduce the production of acetic acid, connected to the S. cerevisiae osmotic stress response.

  3. Formate and acetate as recorded in a mid-latitude glacier in west China

    Institute of Scientific and Technical Information of China (English)

    LI Xinqing (Xinqing LEE); QIN Dahe; HE Yuanqing; ZHANG Caili; ZHOU Hui; JIAO Keqin

    2003-01-01

    Formate and acetate are ubiquitous in the troposphere. Their occurrence is closely related to processes in the biosphere and contributes to an understanding of carbon biogeochemical cycles. A 43-year record of formate and acetate in an ice core from Glacier 1 (43°06′N, 86°49′E) at Urumqi river head, Tianshan, west China was investigated. Fluctuating between 22.7 ng·g-1 and 2830.7 ng·g-1, acetate concentration averages 373.2 ± 376.1 ng·g-1 (mean ± 1σ, N = 541) and is the highest anion in the record. Next to acetate, the concentration for formate varies between 2.1 ng·g-1 and 795.5 ng·g-1 and averages 61.1 ± 89.0ng·g-1 (N = 541). The formate to acetate ratio averages 0.22 ± 0.25 (N = 541), indicating that the chief source is from fossil fuel combustion, coal burning in particular. The two species co-varied in the past four decades and exhibited periods of high concentration from the early 1960s to the middle of 1970s and from the early 1980s to the middle of 1990s, separated by a time of the lower concentration between 1975-1980. These variations may reflect the local/regional anthropogenic pollution to the atmosphere as well as the economic development of northwestern China.

  4. Enzymatic production of biodiesel from microalgal oil using ethyl acetate as an acyl acceptor.

    Science.gov (United States)

    Alavijeh, Razieh Shafiee; Tabandeh, Fatemeh; Tavakoli, Omid; Karkhane, Aliasghar; Shariati, Parvin

    2015-01-01

    Microalgae have become an important source of biomass for biodiesel production. In enzymatic transesterification reaction, the enzyme activity is decreased in presence of alcohols. The use of different acyl acceptors such as methyl/ethyl acetate is suggested as an alternative and effective way to overcome this problem. In this study, ethyl acetate was used for the first time in the enzymatic production of biodiesel by using microalga, Chlorella vulgaris, as a triglyceride source. Enzymatic conversion of such fatty acids to biodiesel was catalyzed by Novozym 435 as an efficient immobilized lipase which is extensively used in biodiesel production. The best conversion yield of 66.71% was obtained at the ethyl acetate to oil molar ratio of 13:1 and Novozym 435 concentration of 40%, based on the amount of oil, and a time period of 72 h at 40℃. The results showed that ethyl acetate have no adverse effect on lipase activity and the biodiesel amount was not decreased even after seven transesterification cycles, so ethyl acetate has a great potential to be substituted for short-chain alcohols in transesterification reaction.

  5. Acetic Acid Detection Threshold in Synthetic Wine Samples of a Portable Electronic Nose

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    Miguel Macías Macías

    2012-12-01

    Full Text Available Wine quality is related to its intrinsic visual, taste, or aroma characteristics and is reflected in the price paid for that wine. One of the most important wine faults is the excessive concentration of acetic acid which can cause a wine to take on vinegar aromas and reduce its varietal character. Thereby it is very important for the wine industry to have methods, like electronic noses, for real-time monitoring the excessive concentration of acetic acid in wines. However, aroma characterization of alcoholic beverages with sensor array electronic noses is a difficult challenge due to the masking effect of ethanol. In this work, in order to detect the presence of acetic acid in synthetic wine samples (aqueous ethanol solution at 10% v/v we use a detection unit which consists of a commercial electronic nose and a HSS32 auto sampler, in combination with a neural network classifier (MLP. To find the characteristic vector representative of the sample that we want to classify, first we select the sensors, and the section of the sensors response curves, where the probability of detecting the presence of acetic acid will be higher, and then we apply Principal Component Analysis (PCA such that each sensor response curve is represented by the coefficients of its first principal components. Results show that the PEN3 electronic nose is able to detect and discriminate wine samples doped with acetic acid in concentrations equal or greater than 2 g/L.

  6. Response of anaerobes to methyl fluoride, 2-bromoethanesulfonate and hydrogen during acetate degradation.

    Science.gov (United States)

    Hao, Liping; Lü, Fan; Li, Lei; Shao, Liming; He, Pinjing

    2013-05-01

    To use the selective inhibition method for quantitative analysis of acetate metabolism in methanogenic systems, the responses of microbial communities and metabolic activities, which were involved in anaerobic degradation of acetate, to the addition of methyl fluoride (CH3F), 2-bromoethanesulfonate (BES) and hydrogen were investigated in a thermophilic batch experiment. Both the methanogenic inhibitors, i.e., CH3F and BES, showed their effectiveness on inhibiting CH4 production, whereas acetate metabolism other than acetoclastic methanogenesis was stimulated by BES, as reflected by the fluctuated acetate concentration. Syntrophic acetate oxidation was thermodynamically blocked by hydrogen (H2), while H2-utilizing reactions as hydrogenotrophic methanogenesis and homoacetogenesis were correspondingly promoted. Results of PCR-DGGE fingerprinting showed that, CH3F did not influence the microbial populations significantly. However, the BES and hydrogen notably altered the bacterial community structures and increased the diversity. BES gradually changed the methanogenic community structure by affecting the existence of different populations to different levels, whilst H2 greatly changed the abundance of different methanogenic populations, and induced growth of new species.

  7. Effects of the use of acetic acid as the conservant in lucerne ensiling

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    Đorđević Nenad

    2004-01-01

    Full Text Available The influence of acetic acid as the chemical conservant in three doses (4, 6 8 g/kg green mass on the intensity of fermentation and proteolysis in lucerne silage was investigated. On the basis of chemical analysis, it was found that with the increase of conservant dose the pH value decreased aminogenesis and nitrogen solubility was limited. In silages treated the absolute and relative domination of acetic acid was found in total acid content. The increase of free and bonded acetic acid was discovered with the increase of conservant dose. Free butyric acid was not detected, while bonded butyric acid was present in negligible concentration, without effect on silage quality. Compared to control silage (III quality class according to DLG and Zelter method, a significant increase of acetic acid in silages resulted in the decline of their quality, and they were ranked as not useful (V quality class according to DLG method, or on the margin of usefulness (IV quality class according to Zelter method. In spite of some foreign references, domestic experiences show that acetic acid is not an effective conservant and it is not recommended for that use for lucerne that is not simple to ensile.

  8. Mutants of Saccharomyces cerevisiae with defects in acetate metabolism: isolation and characterization of Acn- mutants.

    Science.gov (United States)

    McCammon, M T

    1996-09-01

    The two carbon compounds, ethanol and acetate, can be oxidatively metabolized as well as assimilated into carbohydrate in the yeast Saccharomyces cerevisiae. The distribution of acetate metabolic enzymes among several cellular compartments, mitochondria, peroxisomes, and cytoplasm makes it an intriguing system to study complex metabolic interactions. To investigate the complex process of carbon catabolism and assimilation, mutants unable to grow on acetate were isolated. One hundred five Acn- ("ACetate Nonutilizing") mutants were sorted into 21 complementation groups with an additional 20 single mutants. Five of the groups have defects in TCA cycle enzymes: MDH1, CIT1, ACO1, IDH1, and IDH2. A defect in RTG2, involved in the retrograde communication between the mitochondrion and the nucleus, was also identified. Four genes encode enzymes of the glyoxylate cycle and gluconeogenesis: ICL1, MLS1, MDH2, and PCK1. Five other genes appear to be defective in regulating metabolic activity since elevated levels of enzymes in several metabolic pathways, including the glyoxylate cycle, gluconeogenesis, and acetyl-CoA metabolism, were detected in these mutants: ACN8, ACN9, ACN17, ACN18, and ACN42. In summary, this analysis has identified at least 22 and as many as 41 different genes involved in acetate metabolism.

  9. Experimental study of modifying influence of nanoaquachelate gold citrate on embryotoxicity of lead acetate in rats

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    Shatorna V.F.

    2014-06-01

    Full Text Available Among modern investigations in nanobiotechnology, only a small part of them is devoted to the influence of nanometals on reproductive organs and embryogenesis. Thus, if functions of the separate trace metals are studied well enough, the physiological role of such ultramicroelements as gold is still poorly studied especially in the field of its interaction with other metals. The aim of the research was an experimental study of peculiarities of gold aquananocitrate and lead acetate interaction and their impact on rats’ embryogenesis under condition of combined administration. There were used solutions of lead acetate and citrate gold in experimental models obtained by aquananotehnology. Solutions of metals and nanometals were injected perorally once a day during 19 days of pregnancy: solution of lead acetate in the dose of 0.05 mg/kg and gold aquananocitrate solution in the dose of 1.5 mg/kg. 3 group - control group. Influence of tested substances was assessed by integral and specific indicators using physiological, morphological and quantitative analysis methods. It was established that lead acetate in the dose of 0.05 mg/kg is characterized by severe embryotoxic effect manifested by total embryonic mortality, and reducing number of live fetuses in the offspring. Combined introduction of gold aquananocitrate and lead acetate weakens embryotoxic effect of lead, manifested by increase of corpora lutea number by 30.4%, increase of offspring number by 53.3% and decrease of fetal mortality by 2.3 times.

  10. The Antibacterial Activity of Acetic Acid against Biofilm-Producing Pathogens of Relevance to Burns Patients.

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    Fenella D Halstead

    Full Text Available Localised infections, and burn wound sepsis are key concerns in the treatment of burns patients, and prevention of colonisation largely relies on biocides. Acetic acid has been shown to have good antibacterial activity against various planktonic organisms, however data is limited on efficacy, and few studies have been performed on biofilms.We sought to investigate the antibacterial activity of acetic acid against important burn wound colonising organisms growing planktonically and as biofilms.Laboratory experiments were performed to test the ability of acetic acid to inhibit growth of pathogens, inhibit the formation of biofilms, and eradicate pre-formed biofilms.Twenty-nine isolates of common wound-infecting pathogens were tested. Acetic acid was antibacterial against planktonic growth, with an minimum inhibitory concentration of 0.16-0.31% for all isolates, and was also able to prevent formation of biofilms (at 0.31%. Eradication of mature biofilms was observed for all isolates after three hours of exposure.This study provides evidence that acetic acid can inhibit growth of key burn wound pathogens when used at very dilute concentrations. Owing to current concerns of the reducing efficacy of systemic antibiotics, this novel biocide application offers great promise as a cheap and effective measure to treat infections in burns patients.

  11. Coproduction of acetic acid and electricity by application of microbial fuel cell technology to vinegar fermentation.

    Science.gov (United States)

    Tanino, Takanori; Nara, Youhei; Tsujiguchi, Takuya; Ohshima, Takayuki

    2013-08-01

    The coproduction of a useful material and electricity via a novel application of microbial fuel cell (MFC) technology to oxidative fermentation was investigated. We focused on vinegar production, i.e., acetic acid fermentation, as an initial and model useful material that can be produced by oxidative fermentation in combination with MFC technology. The coproduction of acetic acid and electricity by applying MFC technology was successfully demonstrated by the simultaneous progress of acetic acid fermentation and electricity generation through a series of repeated batch fermentations. Although the production rate of acetic acid was very small, it increased with the number of repeated batch fermentations that were conducted. We obtained nearly identical (73.1%) or larger (89.9%) acetic acid yields than that typically achieved by aerated fermentation (75.8%). The open-cycle voltages measured before and after fermentation increased with the total fermentation time and reached a maximum value of 0.521 V prior to the third batch fermentation. The maximum current and power densities measured in this study (19.1 μA/cm² and 2.47 μW/cm², respectively) were obtained after the second batch fermentation.

  12. Recovery of arabinan in acetic acid-catalyzed hydrothermal pretreatment on corn stover

    DEFF Research Database (Denmark)

    Xu, Jian; Hedegaard, Mette Christina; Thomsen, Anne Belinda

    2009-01-01

    Acetic acid-catalyzed hydrothermal pretreatment was done on corn stover under 195 °C, 15 min with the acetic acid ranging from 5 × 10−3 to 0.2 g g−1 corn stover. After pretreatment, the water-insoluble solids (WISs) and liquors were collected respectively. Arabinan recoveries from both WIS...... and liquors were investigated. The results indicate that there was no detectable arabinan left in the WIS when the acetic acid of 0.1 and 0.2 g g−1 corn stover were used in the pretreatment. The arabinan contents in the other WISs were not more than 10%. However, the arabinan found in the liquors...... was not covering the amount of arabinan released from the raw corn stover. For the arabinan recovery from liquor fractions, the highest of 43.57% was obtained by the pretreatment of acetic acid of 0.01 g g−1 of corn stover and the lowest was only 26.77% when the acetic acid of 0.2 g g−1 corn stover was used...

  13. Acetic acid production from marine algae. Progress report No. 2, September 30--December 31, 1977

    Energy Technology Data Exchange (ETDEWEB)

    1977-01-01

    Preliminary results on the production of acetic acid from marine algae by anaerobic fermentation indicate that the rate is quite fast. First order rate constants of 0.77 day/sup -1/ were observed. This rate constant gives a half-life of less than one day. In other words, with a properly designed product removal system a five day retention time would yield 98% of theoretical conversion. Determination of the theoretical conversion of marine algae to acetic acid is the subject of much experimentation. The production of one acetic acid molecule (or equivalent in higher organic acids) for each three carbon atoms in the substrate has been achieved; but it is possible that with a mixed culture more than one acetic acid molecule may be produced for each three carbons in the substrate. Work is continuing to improve the yield of acetic acid from marine algae. Marine algae have been found to be rather low in carbon, but the carbon appears to be readily available for fermentation. It, therefore, lends itself to the production of higher value chemicals in relatively expensive equipment, where the rapid conversion rate is particularly cost effective. Fixed packed bed fermenters appear to be desirable for the production of liquid products which are inhibitory to the fermentation from coarse substrates. The inhibitory products may be removed from the fermentation by extraction during recirculation. This technique lends itself to either conventional processing or low capital processing of substrates which require long retention times.

  14. Acetic acid bacteria: A group of bacteria with versatile biotechnological applications.

    Science.gov (United States)

    Saichana, Natsaran; Matsushita, Kazunobu; Adachi, Osao; Frébort, Ivo; Frebortova, Jitka

    2015-11-01

    Acetic acid bacteria are gram-negative obligate aerobic bacteria assigned to the family Acetobacteraceae of Alphaproteobacteria. They are members of the genera Acetobacter, Gluconobacter, Gluconacetobacter, Acidomonas, Asaia, Kozakia, Swaminathania, Saccharibacter, Neoasaia, Granulibacter, Tanticharoenia, Ameyamaea, Neokomagataea, and Komagataeibacter. Many strains of Acetobacter and Komagataeibacter have been known to possess high acetic acid fermentation ability as well as the acetic acid and ethanol resistance, which are considered to be useful features for industrial production of acetic acid and vinegar, the commercial product. On the other hand, Gluconobacter strains have the ability to perform oxidative fermentation of various sugars, sugar alcohols, and sugar acids leading to the formation of several valuable products. Thermotolerant strains of acetic acid bacteria were isolated in order to serve as the new strains of choice for industrial fermentations, in which the cooling costs for maintaining optimum growth and production temperature in the fermentation vessels could be significantly reduced. Genetic modifications by adaptation and genetic engineering were also applied to improve their properties, such as productivity and heat resistance.

  15. Acetate accumulation enhances mixed culture fermentation of biomass to lactic acid.

    Science.gov (United States)

    Khor, Way Cern; Roume, Hugo; Coma, Marta; Vervaeren, Han; Rabaey, Korneel

    2016-10-01

    Lactic acid is a high-in-demand chemical, which can be produced through fermentation of lignocellulosic feedstock. However, fermentation of complex substrate produces a mixture of products at efficiencies too low to justify a production process. We hypothesized that the background acetic acid concentration plays a critical role in lactic acid yield; therefore, its retention via selective extraction of lactic acid or its addition would improve overall lactic acid production and eliminate net production of acetic acid. To test this hypothesis, we added 10 g/L of acetate to fermentation broth to investigate its effect on products composition and concentration and bacterial community evolution using several substrate-inoculum combinations. With rumen fluid inoculum, lactate concentrations increased by 80 ± 12 % (cornstarch, p 69 % lactic acid bacteria (LAB), predominantly Lactobacillaceae. Higher acetate concentration promoted a more diverse LAB population, especially on non-inoculated bottles. In subsequent tests, acetate was added in a semi-continuous percolation system with grass as substrate. These tests confirmed our findings producing lactate at concentrations 26 ± 5 % (p lactic acid production from waste biomass to levels more attractive for application.

  16. Effect of acetic acid on rice seeds coated with rice husk ash

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    Lizandro Ciciliano Tavares

    2013-06-01

    Full Text Available Flooded rice cultivation promotes anaerobic conditions, favoring the formation of short chain organic acids such as acetic acid, which may be toxic to the crop. The objective of this study was to evaluate the effect of acetic acid on rice seeds coated with rice husk ash. The experiment was arranged in a 2 x 5 x 5 factorial randomized design, with two cultivars (IRGA 424 and BRS Querência, five doses of coating material (0, 2, 3,4 e 5 g kg-1 seed and five concentrations of acetic acid (0, 3, 6, 9 and 12 mM, with 4 replications, totaling 50 treatments. The variables first count of germination, germination, shoot and root length, dry weight of shoots and roots were recorded. The results showed that coating rice seeds with rice husk ash up to 5 g kg-1 seed does not influence the performance of rice seeds of cultivars IRGA 424 and BRS Querência when exposed to concentrations of 12 mM acetic acid. The presence of acetic acid in the substrates used for seed germination reduced the vigor and viability of seeds of cultivars IRGA 424 and BRS Querência, as well as seedling development, affecting mainly the roots of BRS Querência.

  17. RESEARCH ON THE INFLUENCE OF LEAD ACETATE ON THE GAMETOPHYTE OF SOME PTERIDOPHYTE SPECIES

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    Liliana Cristina SOARE

    2014-06-01

    Full Text Available The aim of this research was to study the influence of lead acetate on spore germination and gametophyte differentiation in the pteridophyte species Athyrium filix-femina, Dryopteris affinis and Dryopteris carthusiana. The study was conducted to determine the lead tolerance level of these species.The experimental variants were: Control - Knop solution, V1-100 ppm lead acetate and V2-500 ppm lead acetate. The spores were cultivated in 50 ml of experimental solutions. The culture vessels were kept in the growth room in controlled conditions. The percentage of spore germination was determined after two weeks. Microscopic observations were performed on gametophyte development after 3, 7 and 15 weeks, respectively from the initiation of cultures. Lead acetate influenced both spore germination and gametophyte differentiation. As regards the germination process, Athyrium filix-femina was the least influenced by the lead acetate added to its culture medium. In addition to the decline in germination percentages, we also recorded a delay in the process of gametophyte differentiation and necrosis of prothallic cells. In the V2 variant we noticed the inhibition of cell division in the germinated spores; no further gametophyte differentiation occurred. Athyrium filix-femina is a more tolerant species to this substance as compared with Dryopteris affinis and Dryopteris carthusiana.

  18. Formation of ethyl acetate from whey by Kluyveromyces marxianus on a pilot scale.

    Science.gov (United States)

    Löser, Christian; Urit, Thanet; Stukert, Anton; Bley, Thomas

    2013-01-10

    Whey arising in huge amounts during milk processing is a valuable renewable resource in the field of White Biotechnology. Kluyveromyces marxianus is able to convert whey-borne lactose into ethyl acetate, an environmentally friendly solvent. Formation of ethyl acetate as a bulk product is triggered by iron (Fe). K. marxianus DSM 5422 was cultivated aerobically in whey-borne medium originally containing 40 μg/L Fe, supplemented with 1, 3 or 10 mg/L Fe in the pre-culture, using an 1 L or 70 L stirred reactor. The highest Fe content in the pre-culture promoted yeast growth in the main culture causing a high sugar consumption for growth and dissatisfactory formation of ethyl acetate, while the lowest Fe content limited yeast growth and promoted ester synthesis but slowed down the process. An intermediate Fe dose (ca. 0.5 μg Fe/g sugar) lastly represented a compromise between some yeast growth, a quite high yield of ethyl acetate and an acceptable duration of the process. The mass of ethyl acetate related to the sugar consumed amounted to 0.113, 0.265 and 0.239 g/g in the three processes corresponding to 21.9%, 51.4% and 46.3% of the theoretically maximum yield. The performance on a pilot scale was somewhat higher than on lab scale.

  19. Effect of Potent Ethyl Acetate Fraction of Stereospermum suaveolens Extract in Streptozotocin-Induced Diabetic Rats

    Directory of Open Access Journals (Sweden)

    T. Balasubramanian

    2012-01-01

    Full Text Available To evaluate the antihyperglycemic effect of ethyl acetate fraction of ethanol extract of Stereospermum suaveolens in streptozotocin-(STZ- induced diabetic rats by acute and subacute models. In this paper, various fractions of ethanol extract of Stereospermum suaveolens were prepared and their effects on blood glucose levels in STZ-induced diabetic rats were studied after a single oral administration (200?mg/kg. Administration of the ethyl acetate fraction at 200?mg/kg once daily for 14 days to STZ-induced diabetic rats was also carried out. The parameters such as the fasting blood glucose, hepatic glycogen content, and pancreatic antioxidant levels were monitored. In the acute study, the ethyl acetate fraction is the most potent in reducing the fasting serum glucose levels of the STZ-induced diabetic rats. The 14-day repeated oral administration of the ethyl acetate fraction significantly reduced the fasting blood glucose and pancreatic TBARS level and significantly increased the liver glycogen, pancreatic superoxide dismutase, and catalase activities as well as reduced glutathione levels. The histopathological studies during the subacute treatment have been shown to ameliorate the STZ-induced histological damage of pancreas. This paper concludes that the ethyl acetate fraction from ethanol extract of Stereospermum suaveolens possesses potent antihyperglycemic and antioxidant properties, thereby substantiating the use of plant in the indigenous system of medicine.

  20. Isolation of acetic, propionic and butyric acid-forming bacteria from biogas plants.

    Science.gov (United States)

    Cibis, Katharina Gabriela; Gneipel, Armin; König, Helmut

    2016-02-20

    In this study, acetic, propionic and butyric acid-forming bacteria were isolated from thermophilic and mesophilic biogas plants (BGP) located in Germany. The fermenters were fed with maize silage and cattle or swine manure. Furthermore, pressurized laboratory fermenters digesting maize silage were sampled. Enrichment cultures for the isolation of acid-forming bacteria were grown in minimal medium supplemented with one of the following carbon sources: Na(+)-dl-lactate, succinate, ethanol, glycerol, glucose or a mixture of amino acids. These substrates could be converted by the isolates to acetic, propionic or butyric acid. In total, 49 isolates were obtained, which belonged to the phyla Firmicutes, Tenericutes or Thermotogae. According to 16S rRNA gene sequences, most isolates were related to Clostridium sporosphaeroides, Defluviitoga tunisiensis and Dendrosporobacter quercicolus. Acetic, propionic or butyric acid were produced in cultures of isolates affiliated to Bacillus thermoamylovorans, Clostridium aminovalericum, Clostridium cochlearium/Clostridium tetani, C. sporosphaeroides, D. quercicolus, Proteiniborus ethanoligenes, Selenomonas bovis and Tepidanaerobacter sp. Isolates related to Thermoanaerobacterium thermosaccharolyticum produced acetic, butyric and lactic acid, and isolates related to D. tunisiensis formed acetic acid. Specific primer sets targeting 16S rRNA gene sequences were designed and used for real-time quantitative PCR (qPCR). The isolates were physiologically characterized and their role in BGP discussed.

  1. Investigation of metabolic changes in STZ-induced diabetic rats with hyperpolarized [1-13C]acetate

    DEFF Research Database (Denmark)

    Koellisch, Ulrich; Laustsen, Christoffer; Nørlinger, Thomas S;

    2015-01-01

    in diabetes patients. Acetylcarnitine is a metabolic product of acetate, which enables its transport into the mitochondria for energy production. This study investigates whether the ratio of acetylcarnitine to acetate, measured by noninvasive hyperpolarized [1-(13)C]acetate magnetic resonance spectroscopy......In the metabolism of acetate several enzymes are involved, which play an important role in free fatty acid oxidation. Fatty acid metabolism is altered in diabetes patients and therefore acetate might serve as a marker for pathological changes in the fuel selection of cells, as these changes occur......, could serve as a marker for myocardial, hepatic, and renal metabolic changes in rats with Streptozotocin (STZ)-induced diabetes in vivo. We demonstrate that the conversion of acetate to acetylcarnitine could be detected and quantified in all three organs of interest. More interestingly, we found...

  2. Intracellular storage of acetate/starch mixture by fast growing microbial culture in sequencing batch reactor under continuous feeding.

    Science.gov (United States)

    Ciggin, Asli Seyhan; Majone, Mauro; Orhon, Derin

    2012-09-01

    The paper evaluated intracellular storage formation in fast growing microbial culture fed with acetate/starch mixture under continuous feeding. Three parallel laboratory-scale sequencing batch reactors (SBRs) were operated at a sludge age of 2 days: one of the SBRs was fed with acetate/starch mixture and the other two with acetate and starch, respectively, for comparing the results with single substrate systems. Despite continuous feeding, both acetate and starch components in the substrate mixture were partially converted to storage biopolymers. Poly-hydroxybutyrate (PHB) and glycogen pools were formed during SBR operation at steady state. Only a limited fraction of 12% of the acetate fed during each cycle generated PHB storage while the rest was directly utilized for microbial growth. Around half of the starch fraction of the substrate mixture was converted to glycogen. Increasing the sludge age to 8 days did not affect storage stoichiometry both for acetate and starch in the mixture.

  3. Kinetics and Mechanism of Oxidation of Phenyl Acetic Acid and Dl-Mandelic Acid by Permanganate in Acid Medium

    Directory of Open Access Journals (Sweden)

    B.Syama Sundar

    2014-06-01

    Full Text Available Kinetics of oxidation of phenyl acetic acid and DL- Mandelic acid by potassium permanganate in aqueous acetic acid and perchloric acid mixture reveals that the kinetic orders are first order in oxidant, first order in H+ and zero order in substrate for phenyl acetic acid. DL-Mandelic acid exhibits first order in oxidant and zero order in substrate. The results are rationalised by a mechanism involving intermediate formation of mandelic acid in case of Phenyl acetic acid and ester formation with Mn (VII in case of DL-Mandelic acid. The following order of reactivity is observed: DL-Mandelic acid > Phenyl acetic acid. The high reactivity of DL-Mandelic acid over phenyl acetic acid may be due to different mechanisms operating with the two substrates and benzaldehyde is the final product in both the cases.

  4. Transcript and metabolite alterations increase ganoderic acid content in Ganoderma lucidum using acetic acid as an inducer.

    Science.gov (United States)

    Ren, Ang; Li, Xiong-Biao; Miao, Zhi-Gang; Shi, Liang; Jaing, Ai-Liang; Zhao, Ming-Wen

    2014-12-01

    Acetic acid at 5-8 mM increased ganoderic acid (GA) accumulation in Ganoderma lucidum. After optimization by the response surface methodology, the GA content reached 5.5/100 mg dry weight, an increase of 105% compared with the control. The intermediate metabolites of GA biosynthesis, lanosterol and squalene also increased to 47 and 15.8 μg/g dry weight, respectively, in response to acetic acid. Acetic acid significantly induced transcription levels of sqs, lano, hmgs and cyp51 in the GA biosynthesis pathway. An acetic acid-unregulated acetyl coenzyme A synthase (acs) gene was selected from ten candidate homologous acs genes. The results indicate that acetic acid alters the expression of genes related to acetic acid assimilation and increases GA biosynthesis and the metabolic levels of lanosterol, squalene and GA-a, thereby resulting in GA accumulation.

  5. Conjugation chemistry through acetals toward a dextran-based delivery system for controlled release of siRNA

    KAUST Repository

    Cui, Lina

    2012-09-26

    New conjugation chemistry for polysaccharides, exemplified by dextran, was developed to enable the attachment of therapeutic or other functional moieties to the polysaccharide through cleavable acetal linkages. The acid-lability of the acetal groups allows the release of therapeutics under acidic conditions, such as that of the endocytic compartments of cells, regenerating the original free polysaccharide in the end. The physical and chemical behavior of these acetal groups can be adjusted by modifying their stereoelectronic and steric properties, thereby providing materials with tunable degradation and release rates. We have applied this conjugation chemistry in the development of water-soluble siRNA carriers, namely acetal-linked amino-dextrans, with various amine structures attached through either slow- or fast-degrading acetal linker. The carriers with the best combination of amine moieties and structural composition of acetals showed high in vitro transfection efficiency and low cytotoxicity in the delivery of siRNA. © 2012 American Chemical Society.

  6. Overview of the effects of Ringer's acetate solution and a new concept: renal ketogenesis during hepatic inflow occlusion.

    Science.gov (United States)

    Nakatani, T

    2001-11-01

    Developments in infusion therapy with sodium lactate administered with its isomer, and developments in acetate utilization, both as an infusate or a dialysate, have been previously described, as have the various effects of sodium acetate on cardiovascular function, metabolism and fluid replacement. Unfavorable effects of acetate infusate or dialysate, such as cardiovascular depression, have also been reported, and although the number of studies reporting favorable effects on cardiovascular metabolism is increasing, it is still a matter of controversy. It is clear, however, that acetate can be metabolized in the liver as well as in extrahepatic organs yielding bicarbonate, which can be utilized as an alkalizing agent. Recently, the authors reported new experimental findings that sodium acetate was metabolized to ketone bodies by the kidney during hepatic inflow occlusion. Ketone bodies attract considerable attention as energy substrates in the stress phase and in the reduced redox state. Administration of sodium acetate under such conditions may therefore contribute as substrate supply.

  7. Tocopheryl acetate 20% spray for elimination of head louse infestation: a randomised controlled trial comparing with 1% permethrin creme rinse

    OpenAIRE

    Burgess, Ian F; Burgess, Nazma A.; Brunton, Elizabeth R.

    2013-01-01

    Background Tocopheryl acetate is viscous oily fluid used in a range of preparations for skin and scalp care in Italy. Observational and in vitro data have suggested a high level of efficacy against head louse infestation. The purpose of this investigation was to confirm the activity of tocopheryl acetate in a clinical setting in comparison with a standard widely used preparation. Methods A spray formulation containing tocopheryl acetate 20% in cyclomethicone was compared with permethrin 1% cr...

  8. Balance of Activities of Alcohol Acetyltransferase and Esterase in Saccharomyces cerevisiae Is Important for Production of Isoamyl Acetate

    OpenAIRE

    Fukuda, Kiyoshi; Yamamoto, Nagi; Kiyokawa, Yoshifumi; Yanagiuchi, Toshiyasu; Wakai, Yoshinori; Kitamoto, Katsuhiko; Inoue, Yoshiharu; Kimura, Akira

    1998-01-01

    Isoamyl acetate is synthesized from isoamyl alcohol and acetyl coenzyme A by alcohol acetyltransferase (AATFase) in Saccharomyces cerevisiae and is hydrolyzed by esterases at the same time. We hypothesized that the balance of both enzyme activities was important for optimum production of isoamyl acetate in sake brewing. To test this hypothesis, we constructed yeast strains with different numbers of copies of the AATFase gene (ATF1) and the isoamyl acetate-hydrolyzing esterase gene (IAH1) and ...

  9. Dissemination and Application of New Technology Relating to Catalytic Rectification/Hydrolysis of Methyl Acetate Developed by Fuzhou University

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The new process for catalytic rectification/hydrolysis of methyl acetate developed by the Chemistry and Chemical Engineering College of Fuzhou University has been dissemi-nated and applied. This process adopts the new integrated technology of catalytic rectification which not only has tack-led the problem of low rate of hydrolysis of methyl acetate obtained in the course of PVA manufacture, but is also be-ing applied in the PTA industry to realize the utilization of byproducts of methyl acetate.

  10. Recovery of Acetic Acid from An Ethanol Fermentation Broth by Liquid-Liquid Extraction (LLE) Using Various Solvents

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Thi Thu Huong; Kim, Tae Hyun [Kongju National University, Cheonan (Korea, Republic of); Um, Byung Hwan [Hankyong National University, Anseong (Korea, Republic of)

    2015-12-15

    Liquid-liquid extraction (LLE) using various solvents was studied for recovery of acetic acid from a synthetic ethanol fermentation broth. The microbial fermentation of sugars presented in hydrolyzate gives rise to acetic acid as a byproduct. In order to obtain pure ethanol for use as a biofuel, fermentation broth should be subjected to acetic acid removal step and the recovered acetic acid can be put to industrial use. Herein, batch LLE experiments were carried out at 25°C using a synthetic fermentation broth comprising 20.0 g l{sup -1} acetic acid and 5.0 g l{sup -1} ethanol. Ethyl acetate (EtOAc), tri-n-octylphosphine oxide (TOPO), tri-n-octylamine (TOA), and tri-n-alkylphosphine oxide (TAPO) were utilized as solvents, and the extraction potential of each solvent was evaluated by varying the organic phase-to-aqueous phase ratios as 0.2, 0.5, 1.0, 2.0, and 4.0. The highest acetic acid extraction yield was achieved with TAPO; however, the lowest ethanol-to-acetic acid extraction ratio was obtained using TOPO. In a single-stage batch extraction, 97.0 % and 92.4 % of acetic acid could be extracted using TAPO and TOPO when the ratio of organic-to-aqueous phases is 4:1 respectively. A higher solvent-to-feed ratio resulted in an increase in the ethanol-to-acetic acid ratio, which decreased both acetic acid purity and acetic acid extraction yield.

  11. STUDY OF CARBONYLATION OF METHANOL TO ACETIC ACID AND ACETIC ANHYDRIDE OVER A BIDENTATE POLYMER BOUND CIS-DICARBONYLRHODIUM COMPLEX AS CATALYST

    Institute of Scientific and Technical Information of China (English)

    WANG Xiaojun; LIU Zhongyang; PAN Pinglai; YUAN Guoqing

    1996-01-01

    Copolymer of 2-vinylpyridine and vinylacetate coordinated with dicarbonylrhodium used as a catalyst for carbonylation of methanol to acetic acid and anhydride has been studied. The structural characteristics of the copolymer ligand and complex, and the influences of the reaction conditions on the carbonylation catalyzed by this polymer complex have been investigated. In comparison with small molecule catalyst of Rh complex, the bidentate copolymer coordinated complex has better thermal stability. The reaction mechanism of the carbonylation reaction is also illustrated.

  12. Characterization and Antioxidant Properties of Six Algerian Propolis Extracts: Ethyl Acetate Extracts Inhibit Myeloperoxidase Activity

    Directory of Open Access Journals (Sweden)

    Yasmina Mokhtaria Boufadi

    2014-02-01

    Full Text Available Because propolis contains many types of antioxidant compounds such as polyphenols and flavonoids, it can be useful in preventing oxidative damages. Ethyl acetate extracts of propolis from several Algerian regions show high activity by scavenging free radicals, preventing lipid peroxidation and inhibiting myeloperoxidase (MPO. By fractioning and assaying ethyl acetate extracts, it was observed that both polyphenols and flavonoids contribute to these activities. A correlation was observed between the polyphenol content and the MPO inhibition. However, it seems that kaempferol, a flavonoid, contributes mainly to the MPO inhibition. This molecule is in a high amount in the ethyl acetate extract and demonstrates the best efficiency towards the enzyme with an inhibiting concentration at 50% of 4 ± 2 µM.

  13. TOXICOLOGICAL STUDIES AND CYTOTOXIC ACTIVITY OF ETHANOL AND ETHYL ACETATE EXTRACTS OF TECOMARIA CAPENSIS LEAVES

    Directory of Open Access Journals (Sweden)

    E. Tamil Jothi

    2013-06-01

    Full Text Available In the present study ethyl acetate and ethanol extracts of leaves of Tecomaria capensis was screened for cytotoxic activity. The cytotoxic activity was performed by two models. One was short term cytotoxicity and another was long term cytotoxicity. In short term cytotoxicity assay Dalton’s lymphoma ascites (DLA and Ehrlich ascites carcinoma (EAC cell lines were used and for long term L929 cell lines (Lungs fibroblast were used. In both methods ethyl acetate and ethanol extracts showed protective action against the cell lines. Comparing both extracts, ethanol extract has shown better cytotoxic activity than the ethyl acetate extract and in comparison of standard both extracts have moderate cytotoxic activity.

  14. Influence of Acetic Acid on Dynamic Behavior of Hydrolazation and Film Forming of Organosilane

    Institute of Scientific and Technical Information of China (English)

    YANG Lixia; ZHANG Wenguang; GU Tao; FENG Jun

    2009-01-01

    The influence of acetic acid on dynamic behavior of hydrolazation and film forming of an expoxy-silane compound(γ-GPS)was investigated by conductivity meter,IR and AFM.The experimental results show that there is an optimal pH value(pH=4-5)for hydrolysis of silane solution,and with the prolongation of hydrolytic time,the promotion of acetic acid on the hydrolyza-tion of silane solution become more obvious.During the adsorption and film forming process,acetic acid could promote the formation of Si-O-Fe bond,which activates hydroxyl group of silanol unit and facilitates this hydroxyl group to react with adjacent silanol unit forming linear condensation polymers.

  15. Abiraterone acetate for patients with metastatic castration-resistant prostate cancer progressing after chemotherapy

    DEFF Research Database (Denmark)

    Sternberg, Cora N; Castellano, Daniel; Daugaard, Gedske

    2014-01-01

    BACKGROUND: In the final analysis of the phase 3 COU-AA-301 study, abiraterone acetate plus prednisone significantly prolonged overall survival compared with prednisone alone in patients with metastatic castration-resistant prostate cancer progressing after chemotherapy. Here, we present the final...... analysis of an early-access protocol trial that was initiated after completion of COU-AA-301 to enable worldwide preapproval access to abiraterone acetate in patients with metastatic castration-resistant prostate cancer progressing after chemotherapy. METHODS: We did a multicentre, open-label, early......-access protocol trial in 23 countries. We enrolled patients who had metastatic castration-resistant prostate cancer progressing after taxane chemotherapy. Participants received oral doses of abiraterone acetate (1000 mg daily) and prednisone (5 mg twice a day) in 28-day cycles until disease progression...

  16. Molecular mechanisms of Saccharomyces cerevisiae stress adaptation and programmed cell death in response to acetic acid

    Directory of Open Access Journals (Sweden)

    Sergio eGiannattasio

    2013-02-01

    Full Text Available Beyond its classical biotechnological applications such as food and beverage production or as a cell factory, the yeast Saccharomyces cerevisiae is a valuable model organism to study fundamental mechanisms of cell response to stressful environmental changes. Acetic acid is a physiological product of yeast fermentation and it is a well-known food preservative due to its antimicrobial action. Acetic acid has recently been shown to cause yeast cell death and aging. Here we shall focus on the molecular mechanisms of S. cerevisiae stress adaptation and programmed cell death in response to acetic acid. We shall elaborate on the intracellular signaling pathways involved in the cross-talk of pro-survival and pro-death pathways underlying the importance of understanding fundamental aspects of yeast cell homeostasis to improve the performance of a given yeast strain in biotechnological applications.

  17. Effects of Temperature, Acetate and Nitrate on Methane Generation from Petroleum Hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    Liu Chunshuang; Zhao Dongfeng; Zhang Yunbo

    2014-01-01

    In this study, the effects of temperature, acetate and nitrate on methane gas production from biodegradation of petroleum hydrocarbons were investigated. The results indicated that methane gas production at 35℃was higher than that obtained at 55℃. The acetate addition signiifcant enhanced the methane production at 35℃, however, at 55℃the nitrate addition could largely promote the methane production. The microbial community structures were revealed by PCR-DGGE. The Actinobacteria, Clostridia, Clostridiales, Syntrophus, Pseudomonas, and Proteobacteria-like bacteria and Methano-cellales, Methanosaeta, Methanomicrobiales, Methanolinea, Thermoprotei-like archaea had been enriched at 35 ℃in the acetate addition test. The Thermoprotei, Proteobacterium, Thermodesulfovibrio-like bacteria and Methanocellales-like ar-chaea had been enriched at 55℃in the nitrate addition test. The results may shed light on the bio-utilization of marginal oil reservoirs for enhancing energy recovery.

  18. Life cycle inventory of sodium acetate and expanded graphite: Short report

    Energy Technology Data Exchange (ETDEWEB)

    Jungbluth, N. [ESU-Services Ltd., Uster (Switzerland); Nguyen, B. [Haute Ecole d' Ingenierie et de Gestion du canton de Vaud, Laboratoire d' Energetique Solaire et de Physique du BATiment, HEIG-VD / LESBAT, Yverdon-les-Bains (Switzerland)

    2008-07-01

    This short report for the Laboratory for Solar Energy and Building Physics at the University of Applied Sciences in Yverdon, Switzerland, takes a look at work being done on the issue of solar energy storage. The use of sodium acetate as a phase-change material is reviewed and considered as being a good way of optimising solar heating systems. The goal of this study was to assess if the energy gain resulting from the use of sodium acetate is balanced out or not by its embodied energy. The study investigated sodium acetate with and without expanded graphite. The paper discusses the life cycle inventory analysis of the two materials and provides some aggregated key indicators for further analysis. In general the ecoinvent methodology has been followed in order to achieve full consistency with the background data used and to provide an assessment of the materials' impact on the environment.

  19. Large prebiotic molecules in space: photo-physics of acetic acid and its isomers

    CERN Document Server

    Puletti, Fabrizio; Mulas, Giacomo; Cecchi-Pestellini, Cesare

    2009-01-01

    An increasing number of large molecules have been positively identified in space. Many of these molecules are of biological interest and thus provide insight into prebiotic organic chemistry in the protoplanetary nebula. Among these molecules, acetic acid is of particular importance due to its structural proximity to glycine, the simplest amino acid. We compute electronic and vibrational properties of acetic acid and its isomers, methyl formate and glycolaldehyde, using density functional theory. From computed photo-absorption cross-sections, we obtain the corresponding photo-absorption rates for solar radiation at 1 AU and find them in good agreement with previous estimates. We also discuss glycolaldehyde diffuse emission in Sgr B2(N), as opposite to emissions from methyl formate and acetic acid that appear to be concentrate in the compact region Sgr B2(N-LMH).

  20. Effect of acetic acid on physical properties of pregelatinized wheat and corn starch gels.

    Science.gov (United States)

    Majzoobi, Mahsa; Kaveh, Zahra; Farahnaky, Asgar

    2016-04-01

    Pregelatinized starches are physically modified starches with ability to absorb water and increase viscosity at ambient temperature. The main purpose of this study was to determine how different concentrations of acetic acid (0, 500, 1000, 10,000 mg/kg) can affect functional properties of pregelatinized wheat and corn starches (PGWS and PGCS, respectively) produced by a twin drum drier. With increasing acetic acid following changes occurred for both samples; cold water solubility (at 25 °C) increased, water absorption and apparent cold water viscosity (at 25 °C) reduced, the smooth surface of the starch particles converted to an uneven surface as confirmed by scanning electron microscopy, cohesiveness, consistency and turbidity of the starch gels reduced while their syneresis increased. It was found that in presence of acetic acid, PGWS resulted in higher water absorption and apparent cold water viscosity and produced more cohesive and turbid gels with less syneresis compared to PGCS.

  1. [Advances in the progress of anti-bacterial biofilms properties of acetic acid].

    Science.gov (United States)

    Gao, Xinxin; Jin, Zhenghua; Chen, Xinxin; Yu, Jia'ao

    2016-06-01

    Bacterial biofilms are considered to be the hindrance in the treatment of chronic wound, because of their tolerance toward antibiotics and other antimicrobial agents. They also have strong ability to escape from the host immune attack. Acetic acid, as a kind of organic weak acid, can disturb the biofilms by freely diffusing through the bacterial biofilms and bacterial cell membrane structure. Then the acid dissociates to release the hydrogen ions, leading to the disorder of the acid-base imbalance, change of protein conformation, and the degradation of the DNA within the membranes. This paper reviews the literature on the characteristics and treatment strategies of the bacterial biofilms and the acetic acid intervention on them, so as to demonstrate the roles acetic acid may play in the treatment of chronic wound, and thus provide a convincing treatment strategy for this kind of disease.

  2. Electrochemical studies of copper, nickel and a Cu55/Ni45 alloy in aqueous sodium acetate

    Directory of Open Access Journals (Sweden)

    Gonçalves Reinaldo Simões

    2001-01-01

    Full Text Available This paper discusses the electrochemical behavior of copper, nickel and a copper/nickel alloy in aerated aqueous 0.10 and 1.0 mol L-1 sodium acetate. The data obtained from different electrochemical techniques were analyzed to determine the influence of Ni and Cu on the electrochemical processes of the alloy electrode. The shapes of the potentiodynamic I(E curves of the alloy were found to be quite similar to those of the Ni voltamograms. Although the anodic current densities of Ni and the alloy increased with greater concentrations of acetate, the opposite effect occurred in Cu. The impedance measurements taken at the open circuit potential revealed that the polarization resistance (R P of the electrodes decreased in the following order: Ni > Alloy > Cu. With increasing concentrations of acetate, the R P of the alloy and the Cu increased while that of the Ni electrode decreased.

  3. The lifespan-promoting effect of acetic acid and Reishi polysaccharide.

    Science.gov (United States)

    Chuang, Ming-Hong; Chiou, Shyh-Horng; Huang, Chun-Hao; Yang, Wen-Bin; Wong, Chi-Huey

    2009-11-15

    Using Caenorhabditis elegans as a model organism, various natural substances and commercial health-food supplements were screened to evaluate their effects on longevity. Among the substances tested, acetic acid and Reishi polysaccharide fraction 3 (RF3) were shown to increase the expression of the lifespan and longevity-related transcription factor DAF-16 in C. elegans. We have shown that RF3 activates DAF-16 expression via TIR-1 receptor and MAPK pathway whereas acetic acid inhibits the trans-membrane receptor DAF-2 of the insulin/IGF-1 pathway to indirectly activate DAF-16 expression. In addition, a mixture of acetic acid and RF3 possesses a combined effect 30-40% greater than either substance used alone. A proteomic analysis of C. elegans using 2-DE and LC-MS/MS was then carried out, and 15 differentially expressed proteins involved in the lifespan-promoting activity were identified.

  4. Modelling of Escherichia coli Cultivations: Acetate Inhibition in a Fed-batch Culture

    Directory of Open Access Journals (Sweden)

    Stoyan Tzonkov

    2006-04-01

    Full Text Available A set of three competing, unstructured models has been proposed to model biomass growth, glucose utilization, acetate formation, dissolved oxygen consumption and carbon dioxide accumulation of a fed-batch cultivation process of Escherichia coli. The inhibiting effect of acetate on growth of E. coli cultures is included in the considered models. The model identification is carried out using experimental data from the cultivation process. Genetic algorithms are used for parameter estimation. The model discrimination is based on the four criteria, namely sum of square errors, Fisher criterion, Akaike information criterion and minimum description length criterion. The most suitable model is identified that reflects the state variables curves adequately by considering acetate inhibited growth according to the Jerusalimsky approach.

  5. Microbiological preservation of cucumbers for bulk storage using acetic acid and food preservatives.

    Science.gov (United States)

    Pérez-Díaz, I M; McFeeters, R F

    2008-08-01

    Microbial growth did not occur when cucumbers were preserved without a thermal process by storage in solutions containing acetic acid, sodium benzoate, and calcium chloride to maintain tissue firmness. The concentrations of acetic acid and sodium benzoate required to ensure preservation were low enough so that stored cucumbers could be converted to the finished product without the need to wash out and discard excess acid or preservative. Since no thermal process was required, this method of preservation would be applicable for storing cucumbers in bulk containers. Acid tolerant pathogens died off in less than 24 h with the pH, acetic acid, and sodium benzoate concentrations required to assure the microbial stability of cucumbers stored at 30 degrees C. Potassium sorbate as a preservative in this application was not effective. Yeast growth was observed when sulfite was used as a preservative.

  6. Skin impression with acetate tape in Demodex canis and Scarcoptes scabiei var. vulpes diagnosis

    Directory of Open Access Journals (Sweden)

    D.T. Pereira

    2015-02-01

    Full Text Available This study compares the efficacy of skin impression with acetate tape and the deep skin scraping test to find D. canis and S. scabiei in dogs. During six months, 134 samples were collected by both techniques from 115 dogs treated at the dermatology service of the Veterinary Hospital of the Federal University of Santa Maria (HVU-UFSM. Of these patients, 27 had demodicosis and 12 had scabies. The impression with acetate tape test (ITT was shown to be significantly superior to the deep skin scraping test (DSST in finding D. canis and S. scabiei mites (p = 0.007. Based on our results we could conclude that acetate tape impression is a reliable method for diagnosing and monitoring therapy of dermatopathies caused by mites and can be used to replace the traditional deep skin scraping method. In addition, since it is less traumatic for the dog, this method shows more acceptance by the owner.

  7. Antioxidant and Antitumor Effect of Different Fractions of Ethyl Acetate Part from Elaeagnus angustifolia L.

    Directory of Open Access Journals (Sweden)

    Wang Ya

    2014-05-01

    Full Text Available To determine antitumor and antioxidant activities of the different fractions of ethyl acetate of Elaeagnus angustifolia L. extract, the MTT assay, the DPPH scavenging assay and the reducing power method were used. The results showed that as the concentration and the polarity were increasing, the antioxidant activity of the different fractions of ethyl acetate of Elaeagnus angustifolia L. extract was increased. The DPPH scavenging of the E and F fractions was 94.9%. The antitumor assay showed that the different fractions of ethyl acetate of Elaeagnus angustifolia L. exhibited the inhibition of the in vitro cultured Hela cell proliferation properties. During the first 48 h, there was a dependant relation of inhibition effect and the concentration and the polarity. The higher the concentration and the polarity, the stronger the inhibition effect was. The inhibition rate was 74.34% when the concentration of F faction was 2.5 mg/mL.

  8. A STUDY OF THE EFFECT OF ACETYLATION ON HEMP FIBRES WITH VINYL ACETATE

    Directory of Open Access Journals (Sweden)

    Nilgül Özmen

    2012-07-01

    Full Text Available Chemical modifications of hemp fibers were performed with acetic anhydride (AA and vinyl acetate (VA in the presence of pyridine or potassium carbonate as catalysts. Hemp fibers (Cannabis sativa were successfully acetylated by VA in the presence of potassium carbonate (15% WPG, but no weight gain was obtained when pyridine was used as catalyst. Hemp fibers were also modified with acetic anhydride (AA in the presence of potassium carbonate and pyridine as catalyst (14% and 16% WPG, respectively under identical conditions, and the results were compared with those obtained using the VA technique. AA-modified, VA-modified, and control hemp fibers were characterized by Infrared (FTIR, 13C CP MAS NMR and thermo gravimetric analysis (TGA.

  9. Calcium acetate versus calcium carbonate as phosphorus binders in patients on chronic haemodialysis: a controlled study.

    Science.gov (United States)

    Ring, T; Nielsen, C; Andersen, S P; Behrens, J K; Sodemann, B; Kornerup, H J

    1993-01-01

    The first reported double-blind cross-over comparison between the phosphorus binders calcium carbonate and calcium acetate was undertaken in 15 stable patients on chronic maintenance haemodialysis. Detailed registration of diet and analysis of the protein catabolic rate suggested an unchanged phosphorus intake during the study. It was found that predialytic serum phosphate concentration was significantly decreased by 0.11 mmol/l (0.34 mg/dl) (P = 0.021, 95% confidence limits 0.02-0.21 mmol/l; 0.06-0.65 mg/dl) during calcium acetate treatment. The calcium phosphate product was insignificantly decreased during treatment with calcium acetate whereas we could not exclude the possibility that calcium concentration had increased.

  10. Transformation of acetate carbon into carbohydrate and amino acid metabilites during decomposition in soil

    DEFF Research Database (Denmark)

    Sørensen, Lasse Holst; Paul, E. A.

    1971-01-01

    Carbon-14-labelled acetate was added to a heavy clay soil of pH 7.6 to study the transformation of acetate carbon into carbohydrate and amino acid metabolites during decomposition. The acetate was totally metabolized after 6 days of incubation at 25°C when 70% of the labelled carbon had been...... evolved as CO2. Maximum incorporation of trace-C into the various organic fractions was observed after 4 days when 19% of residual, labelled carbon in the soil was located in carbohydrates, 29 % in amino acids and 21 % in the insoluble residue of the soil. The curves showing the amounts of labelled carbon...... located in carbohydrates and amino acid metabolites show a curvilinear form during the first 30 days of incubation, indicating a variety of chemical compounds decaying at different rates. After this time, the decay curves became straight lines indicating a greater homogeneity of the metabolites. After 200...

  11. 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}.

  12. Required catalytic properties for alkane production from carboxylic acids: Hydrodeoxygenation of acetic acid

    Institute of Scientific and Technical Information of China (English)

    Zhong; He; Xianqin; Wang

    2013-01-01

    The supported Pt catalysts(1 wt%)were prepared by the incipient impregnation method and analyzed using synchrotron-based X-ray diffraction,BET surface area,oxygen adsorption,CO pulse chemisorption,temperature-programmed desorption(TPD)of acetic acid,H2-TPD,NH3-TPD,O2-TPD,and H2-TPR.The reactivity of Pt-based catalysts was studied using a fixed bed reactor at 300 C and 4 MPa for hydrodeoxygenation of acetic acid,where Pt/TiO2 was very selective for ethane production.TPD experiments revealed that several conditions must be satisfied to achieve this high selectivity to ethane from acetic acid,such as Pt sites,moderate acidity,and medium metal-oxygen bond strength in the oxide support.This work provides insights in developing novel catalytic materials for hydrocarbon productions from various organics including bio-fuels.

  13. The effects of a co-solvent on fabrication of cellulose acetate membranes from solutions in 1-ethyl-3-methylimidazolium acetate

    KAUST Repository

    Kim, Dooli

    2016-08-15

    Ionic liquids have been considered green solvents for membrane fabrication. However, the high viscosity of their polymer solutions hinders the formation of membranes with strong mechanical properties. In this study, acetone was explored as a co-solvent with the ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc) to dissolve cellulose acetate. The effects of acetone on the thermodynamic and kinetic aspects of the polymer solutions were studied and the physicochemical properties and separation capability of their resultant membranes were analyzed. The Hansen solubility parameters of [EMIM]OAc were measured by the software HSPiP and these data demonstrated that acetone was a suitable co-solvent to increase the solubility of cellulose acetate. The Gibbs free energy of mixing ΔGm was estimated to determine the proper composition of the polymer solution with better solubility. The study of the kinetics of phase separation showed that the demixing rate of the CA polymer solution in acetone and [EMIM]OAc was higher than that for solutions in [EMIM]OAc only. The membranes prepared from the former solution had higher water permeance and better mechanical stability than those prepared from the later solution. Adding acetone as a co-solvent opened the opportunity of fabricating membranes with higher polymer concentrations for higher separation capability and better mechanical properties. © 2016

  14. Evaluation of CO2-philicity of poly(vinyl acetate) and poly(vinyl acetate-alt-maleate) copolymers through molecular modeling and dissolution behavior measurement.

    Science.gov (United States)

    Hu, Dongdong; Sun, Shaojun; Yuan, Peiqing; Zhao, Ling; Liu, Tao

    2015-02-19

    Multiscale molecular modeling and dissolution behavior measurement were both used to evaluate the factors conclusive on the CO2-philicity of poly(vinyl acetate) (PVAc) homopolymer and poly(vinyl acetate-alt-maleate) copolymers. The ab initio calculated interaction energies of the candidate CO2-philic molecule models with CO2, including vinyl acetate dimer (VAc), dimethyl maleate (DMM), diethyl maleate (DEM), and dibutyl maleate (DBM), showed that VAc was the most CO2-philc segment. However, the cohesive energy density, solubility parameter, Flory-Huggins parameter, and radial distribution functions calculated by using the molecular dynamics simulations for the four polymer and polymer-CO2 systems indicated that poly(VAc-alt-DBM) had the most CO2-philicity. The corresponding polymers were synthesized by using free radical polymerization. The measurement of cloud point pressures of the four polymers in CO2 also demonstrated that poly(VAc-alt-DBM) had the most CO2-philicity. Although copolymerization of maleate, such as DEM or DBM, with PVAc reduced the polymer-CO2 interactions, the weakened polymer-polymer interaction increased the CO2-philicity of the copolymers. The polymer-polymer interaction had a significant influence on the CO2-philicity of the polymer. Reduction of the polymer-polymer interaction might be a promising strategy to prepare the high CO2-philic polymers on the premise that the strong polymer-CO2 interaction could be maintained.

  15. A shock tube laser schlieren study of methyl acetate dissociation in the fall-off regime.

    Science.gov (United States)

    Annesley, Christopher J; Franklin Goldsmith, C; Tranter, Robert S

    2014-04-28

    The pyrolysis of methyl acetate, 2% and 4% dilute in krypton, was investigated in a diaphragmless shock tube (DFST) using laser schlieren densitometry (LS). Experiments were performed at 122 ± 3 and 63 ± 2 Torr over the temperature range of 1492-2266 K. Master equation models for the four main dissociation paths of methyl acetate based on a prior study by Peukert et al. [S. Peukert, R. Sivaramakrishnan, M. Su and J. Michael, Combust. Flame, 2012, 159, 2312-2323] were refined and formed the basis for simulating the LS experiments. The density gradient profiles from the LS experiments indicate that the initial dissociation proceeds predominantly by breakage of the C-O bond leading ultimately to two methyl radicals and CO2, accounting for 83-88% of the methyl acetate loss over this temperature range. Rate coefficients for dissociation of methyl acetate were satisfactorily simulated with a master equation model, with modelled rate coefficients of k120 Torr = 9.06 × 10(81) × T(-19.07) × exp(-61 600K/T) s(-1), k60 Torr = 3.71 × 10(82) × T(-19.34) × exp(-61 200K/T) s(-1), and of k∞ = 1.97 × 10(30) × T(-3.80) × exp(-47 900K/T) s(-1) for the major channel, based on fitting to 120 Torr and 60 Torr data taken in this study. The model also captures the pressure dependency of methyl acetate dissociation and resolves an earlier discrepancy concerning the mechanism of dissociation of methyl acetate.

  16. Increasing anaerobic acetate consumption and ethanol yields in Saccharomyces cerevisiae with NADPH-specific alcohol dehydrogenase.

    Science.gov (United States)

    Henningsen, Brooks M; Hon, Shuen; Covalla, Sean F; Sonu, Carolina; Argyros, D Aaron; Barrett, Trisha F; Wiswall, Erin; Froehlich, Allan C; Zelle, Rintze M

    2015-12-01

    Saccharomyces cerevisiae has recently been engineered to use acetate, a primary inhibitor in lignocellulosic hydrolysates, as a cosubstrate during anaerobic ethanolic fermentation. However, the original metabolic pathway devised to convert acetate to ethanol uses NADH-specific acetylating acetaldehyde dehydrogenase and alcohol dehydrogenase and quickly becomes constrained by limited NADH availability, even when glycerol formation is abolished. We present alcohol dehydrogenase as a novel target for anaerobic redox engineering of S. cerevisiae. Introduction of an NADPH-specific alcohol dehydrogenase (NADPH-ADH) not only reduces the NADH demand of the acetate-to-ethanol pathway but also allows the cell to effectively exchange NADPH for NADH during sugar fermentation. Unlike NADH, NADPH can be freely generated under anoxic conditions, via the oxidative pentose phosphate pathway. We show that an industrial bioethanol strain engineered with the original pathway (expressing acetylating acetaldehyde dehydrogenase from Bifidobacterium adolescentis and with deletions of glycerol-3-phosphate dehydrogenase genes GPD1 and GPD2) consumed 1.9 g liter(-1) acetate during fermentation of 114 g liter(-1) glucose. Combined with a decrease in glycerol production from 4.0 to 0.1 g liter(-1), this increased the ethanol yield by 4% over that for the wild type. We provide evidence that acetate consumption in this strain is indeed limited by NADH availability. By introducing an NADPH-ADH from Entamoeba histolytica and with overexpression of ACS2 and ZWF1, we increased acetate consumption to 5.3 g liter(-1) and raised the ethanol yield to 7% above the wild-type level.

  17. [Comparative genomics and evolutionary analysis of CRISPR loci in acetic acid bacteria].

    Science.gov (United States)

    Kai, Xia; Xinle, Liang; Yudong, Li

    2015-12-01

    The clustered regularly interspaced short palindromic repeat (CRISPR) is a widespread adaptive immunity system that exists in most archaea and many bacteria against foreign DNA, such as phages, viruses and plasmids. In general, CRISPR system consists of direct repeat, leader, spacer and CRISPR-associated sequences. Acetic acid bacteria (AAB) play an important role in industrial fermentation of vinegar and bioelectrochemistry. To investigate the polymorphism and evolution pattern of CRISPR loci in acetic acid bacteria, bioinformatic analyses were performed on 48 species from three main genera (Acetobacter, Gluconacetobacter and Gluconobacter) with whole genome sequences available from the NCBI database. The results showed that the CRISPR system existed in 32 species of the 48 strains studied. Most of the CRISPR-Cas system in AAB belonged to type I CRISPR-Cas system (subtype E and C), but type II CRISPR-Cas system which contain cas9 gene was only found in the genus Acetobacter and Gluconacetobacter. The repeat sequences of some CRISPR were highly conserved among species from different genera, and the leader sequences of some CRISPR possessed conservative motif, which was associated with regulated promoters. Moreover, phylogenetic analysis of cas1 demonstrated that they were suitable for classification of species. The conservation of cas1 genes was associated with that of repeat sequences among different strains, suggesting they were subjected to similar functional constraints. Moreover, the number of spacer was positively correlated with the number of prophages and insertion sequences, indicating the acetic acid bacteria were continually invaded by new foreign DNA. The comparative analysis of CRISR loci in acetic acid bacteria provided the basis for investigating the molecular mechanism of different acetic acid tolerance and genome stability in acetic acid bacteria.

  18. Effect of acetic acid on optical coherence tomography (OCT) images of cervical epithelium.

    Science.gov (United States)

    Gallwas, Julia; Stanchi, Anna; Dannecker, Christian; Ditsch, Nina; Mueller, Susanna; Mortensen, Uwe; Stepp, Herbert

    2014-11-01

    Optical coherence tomography (OCT) can be used as an adjunct to colposcopy in the identification of precancerous and cancerous cervical lesions. The purpose of this study was to investigate the effect of acetic acid on OCT imaging. OCT images were taken from unsuspicious and suspicious areas of fresh conization specimens immediately after resection and 3 and 10 min after application of 6 % acetic acid. A corresponding histology was obtained from all sites. The images taken 3 and 10 min after application of acetic acid were compared to the initial images with respect to changes in brightness, contrast, and scanning depth employing a standard nonparametric test of differences of proportions. Further, mean intensity backscattering curves were calculated from all OCT images in the histological groups CIN3, inflammation, or normal epithelium. Mean difference profiles within each of these groups were determined, reflecting the mean differences between the condition before application of acetic acid and the exposure times 3 and 10 min, respectively. According to the null hypothesis, the difference profiles do not differ from profiles fluctuating around zero in a stationary way, which implies that the profiles do not differ significantly from each other. The null hypothesis was tested employing the KPSS test. The visual analysis of 137 OCT images from 46 sites of 10 conization specimens revealed a statistically significant increase in brightness for all three groups and a statistically significant decrease in contrast for normal epithelium after 10 min. Further, an increase in scanning depth was noted for normal epithelium after 10 min and for CIN3 after 3 min. The analysis of mean intensity profiles showed an increased backscattering intensity after application of acetic acid. Acetic acid significantly affects the quality of OCT images. Overall brightness and scanning depth increase with the opposite effect regarding the image contrast. Whether the observed changes

  19. Acetate supplementation as a means of inducing glioblastoma stem-like cell growth arrest.

    Science.gov (United States)

    Long, Patrick M; Tighe, Scott W; Driscoll, Heather E; Fortner, Karen A; Viapiano, Mariano S; Jaworski, Diane M

    2015-08-01

    Glioblastoma (GBM), the most common primary adult malignant brain tumor, is associated with a poor prognosis due, in part, to tumor recurrence mediated by chemotherapy and radiation resistant glioma stem-like cells (GSCs). The metabolic and epigenetic state of GSCs differs from their non-GSC counterparts, with GSCs exhibiting greater glycolytic metabolism and global hypoacetylation. However, little attention has been focused on the potential use of acetate supplementation as a therapeutic approach. N-acetyl-l-aspartate (NAA), the primary storage form of brain acetate, and aspartoacylase (ASPA), the enzyme responsible for NAA catalysis, are significantly reduced in GBM tumors. We recently demonstrated that NAA supplementation is not an appropriate therapeutic approach since it increases GSC proliferation and pursued an alternative acetate source. The FDA approved food additive Triacetin (glyceryl triacetate, GTA) has been safely used for acetate supplementation therapy in Canavan disease, a leukodystrophy due to ASPA mutation. This study characterized the effects of GTA on the proliferation and differentiation of six primary GBM-derived GSCs relative to established U87 and U251 GBM cell lines, normal human cerebral cortical astrocytes, and murine neural stem cells. GTA reduced proliferation of GSCs greater than established GBM lines. Moreover, GTA reduced growth of the more aggressive mesenchymal GSCs greater than proneural GSCs. Although sodium acetate induced a dose-dependent reduction of GSC growth, it also reduced cell viability. GTA-mediated growth inhibition was not associated with differentiation, but increased protein acetylation. These data suggest that GTA-mediated acetate supplementation is a novel therapeutic strategy to inhibit GSC growth.

  20. Antioxidant and Cytotoxicity of β-Amyrin acetate fraction fromBridelia ferruginea Leaves

    Institute of Scientific and Technical Information of China (English)

    Oluwatoyin Adenike FABIYI; Olubunmi ATOLANI; Oluyomi S ADEYEMI; Gabriel Ademola OLATUNJI

    2012-01-01

    Objective: The objective of this work was to determine the beta-amyrin acetate fraction in leave extract of Bridelia ferruginea and evaluate for its antioxidant and cytotoxicity potentials. Methods: The dried and pulverized leaves of Bridelia ferruginea was extracted with hexane and then with ethyl acetate. The concentrated ethylacetate extract subjected to silica gel column chromatography and eluted with a mixture of equal volume of hexane and dichloromethane afforded two major fractions. The more polar fraction was concentrated and subjected to GCMS analysis which afforded the steroid, 12-Oleanen-3yl acetate commonly known as beta-amyrin acetate (66.14%). Its ability to act as a scavenger of DPPH radical and its cytotoxicity potential based on brine shrimp assay were investigated. Results: The DPPH antioxidant assay revealed that the fraction had a higher antioxidant potential with an IC50 value of 158.2μg/mL relative to gallic acid which had IC50 of 201.1 μg/mL. The cytotoxicity assay using the brine shrimp a gave LC50 values of 319 and 5.86 μg/mL for acute and lethal doses respectively indicating extreme toxicity when compared to reference drug, cyclophosphamide which had LC50 value of 2506 μg/mL. Conclusions: Thus, the beta-amyrin acetate has been identified for the first time in the leave of Bridelia ferruginea. The data here suggest that the beta-amyrin acetate fraction of the leave of Bridelia ferruginea could be further explored in biological profiling requiring antioxidant and cytotoxic dependent therapeutics as the plant could be a viable source of antioxidant and cytotoxic agents in cancer chemotherapy in the near future.