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1

Development of Acetic Acid Removal Technology for the UREX+Process  

Energy Technology Data Exchange (ETDEWEB)

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.

Robert M. Counce; Jack S. Watson

2009-06-30

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Effects of acetic acid, ethanol, and SO2 on the removal of volatile acidity from acidic wines by two Saccharomyces cerevisiae commercial strains  

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Herein we report the influence of different combinations of initial concentration of acetic acid and ethanol on the removal of acetic acid from acidic wines by two commercial Saccharomyces cerevisiae strains S26 and S29. Both strains reduced the volatile acidity of an acidic wine (1.0 g l-1 acetic acid and 11% (v/v) ethanol) by 78% and 48%, respectively. Acetic acid removal by both strains was associated with a decrease in ethanol concentration of about 0.7 – 1.2% (v/v). Strain S26 revealed...

Moura, A. Vilela; Schuller, Dorit; Faia, A. Mendes; Co?rte-real, Manuela

2010-01-01

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Removal of dicyclohexyl acetic acid from aqueous solution using ultrasound, ozone and their combination.  

Science.gov (United States)

Naphthenic acids are a complex mixture of organic components, some of which include saturated alkyl-substituted cycloaliphatic carboxylic acids and acyclic aliphatic acids. They are naturally found in hydrocarbon deposits like oil sand, petroleum, bitumen and crude oil. In this study, the oxidation of a relatively high molecular weight naphthenic acid (Dicyclohexyl acetic acid) was investigated using ozonation, ultrasonication and hydrogen peroxide alone and their combinations. Effects on oxidation of dicyclohexyl acetic acid (DAA) were measured for different concentrations of ozone ranging between 0.7 to 3.3 mg L(-1) and pH in the range 6 to 10. Ultrasonication and hydrogen peroxide alone were not effective to oxidize dicyclohexyl acetic acid, but combining ultrasonication with H2O2 had a significant effect on oxidation of dicyclohexyl acetic acid with maximum removal reaching to 84 ± 2.2% with 81 ± 2.1% reduction in chemical oxygen demand (COD). Synergistic effects were observed for combining ultrasonication with ozonation and resulted in 100% DAA removal with 98 ± 0.8% reduction in COD within 15 min at 3.3 mg L(-1) ozone concentration and 130 Watts ultrasonication power. The reaction conditions obtained for the maximum oxidation of DAA and COD removal were used for the degradation of naphthenic acids mixture extracted from oil sands process water (OSPW). The percentage oxidation of NAs mixture extracted from OSPW was 89.3 ± 1.1% in ozonation and combined ozonation and ultrasonication, but COD removal observed was 65 ± 1.2% and 78 ± 1.4% for ozonation and combined ozonation and ultrasonication treatments, respectively. PMID:25137539

Kumar, Pardeep; Headley, John; Peru, Kerry; Bailey, Jon; Dalai, Ajay

2014-01-01

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AN EXPLORATORY STUDY ON THE REMOVAL OF ACETIC AND FORMIC ACIDS FROM BIO-OIL  

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Full Text Available Bio-oil produced from fast pyrolysis of biomass contains various levels of acetic and formic acids derived from breakdown of cellulose and hemi-cellulose components. Removal of these organic acids from bio-oil was investigated for use as industrial chemicals as well as to improve the quality of recovered bio-oil as fuel in various applications. Calcium oxide and a quaternary ammonium anion-exchange resin were used to form acid salts of the organic acids, which were then separated, and the organic acids were generated by reacting with sulfuric acid. Both methods were found to be effective in limited ways and various difficulties encountered in this approach are discussed.

Badmakhand Sukhbaatar

5

Removal of Zn(II from Aqueous Acetate Solution Using Di (2-Ethylhexyl Phosphoric Acid & Tributylphosphate  

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Full Text Available The extraction of Zinc (II in acetate medium with di (2-ethylhexyl phosphoric acid (D2EHPA in chloroform diluent was investigated under different experimental conditions, in order to have a better understanding of the extraction mechanism. The extraction yield was found to depend on the concentrations of Zinc (II and D2EHPA, and the equilibrium pH. The effects of acetic acid and the salting-out agent were also studied. The nature of the extracted species was investigated by the slope analysis method. Graphs of log D vs. log [D2EHPA] and log D vs. pH were plotted for Zn (II, and the species extracted into the organic phase was found to have the composition (ZnCH3COOR.HR. The best performance was reached (80% with zinc concentrations lower than 5 mM in a neutral medium. The extraction yield of metals decreased as the acetic acid concentration increased with any given extractant concentration. The addition of sodium acetate to the aqueous phase strongly increased  the zinc extraction yield (99.5%. A synergistic effect was observed by the addition of tributhylphosphate (TBP with the organic phase.

Brahim Guezzen

2012-05-01

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Antibiofilm Properties of Acetic Acid  

DEFF Research Database (Denmark)

Bacterial biofilms are known to be extremely tolerant toward antibiotics and other antimicrobial agents. These biofilms cause the persistence of chronic infections. Since antibiotics rarely resolve these infections, the only effective treatment of chronic infections is surgical removal of the infected implant, tissue, or organ and thereby the biofilm. Acetic acid is known for its antimicrobial effect on bacteria in general, but has never been thoroughly tested for its efficacy against bacterial biofilms. In this article, we describe complete eradication of both Gram-positive and Gram-negative biofilms using acetic acid both as a liquid and as a dry salt. In addition, we present our clinical experience of acetic acid treatment of chronic wounds. In conclusion, we here present the first comprehensive in vitro and in vivo testing of acetic acid against bacterial biofilms.

Bjarnsholt, Thomas; Alhede, Morten

2014-01-01

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Efficacy of ethylene-diamine-tetra-acetic acid associated with chlorhexidine on intracanal medication removal: a scanning electron microscopy study.  

Science.gov (United States)

The aim of this study was to evaluate the effectiveness of 17% ethylene-diamine-tetra-acetic acid (EDTA) used alone or associated with 2% chlorhexidine gel (CHX) on intracanal medications (ICM) removal. Sixty single-rooted human teeth with fully formed apex were selected. The cervical and middle thirds of each canal were prepared with Gates Glidden drills and rotary files. The apical third was shaped with hand files. The specimens were randomly divided into two groups depending on the ICM used after instrumentation: calcium hydroxide Ca(OH)(2) +CHX or Ca(OH)(2) +sterile saline (SS). After seven days, each group was divided into subgroups according to the protocol used for ICM removal: instrumentation and irrigation either with EDTA, CHX+EDTA, or SS (control groups). All specimens were sectioned and processed for observation of the apical thirds by using scanning electron microscopy. Two calibrated evaluators attributed scores to each specimen. The differences between the protocols for ICM removal were analyzed with Kruskal-Wallis and Mann-Whitney U tests. Friedman and Wilcoxon signed rank tests were used for comparison between the score of debris obtained in each root canal third. Remains of Ca(OH)(2) were found in all specimens independently of the protocol and ICM used (P?>?0.05). Seventeen percent EDTA showed the best results in removing ICM when used alone (P?removal of ICM when used alone. Furthermore, the type of the vehicle associated with Ca(OH)(2) also plays a role in the ICM removal. PMID:24941937

Abi-Rached, Giselle P C; Herrera, Daniel R; Zaia, Alexandre A; Ferraz, Caio C R; Almeida, Jose F A; Gomes, Brenda P F A

2014-09-01

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Removal of aqueous Hg(II) and Cr(VI) using phytic acid doped polyaniline/cellulose acetate composite membrane.  

Science.gov (United States)

Conductive composite membrane-phytic acid (PA) doped polyaniline (PANI)/cellulose acetate (CA) (PANI-PA/CA) was prepared in a simple and environmental-friendly method, in which aniline was blended with CA/PA solution and polymerized before the phase conversion. The resultant composite membranes were characterized by SEM, EDX, FTIR-ATR, BET and electrical resistance measurements. When used as adsorbent for Hg(II) and Cr(VI) ions, the prepared composite membrane exhibits excellent adsorption capability. The adsorption of Hg(II) and Cr(VI) follows a pseudo-second-order kinetic model and best fits the Langmuir isotherm model, with the maximum adsorption capacity reaching 280.11 and 94.34mgg(-1), respectively. The heavy metal loaded composite membrane can be regenerated and reused after treatment with acid or alkali solution, making it a promising and practical adsorbent for Hg(II) and Cr(VI) removal. Tests with river water were also carried out, indicating good performance and application. PMID:25127386

Li, Renjie; Liu, Lifen; Yang, Fenglin

2014-09-15

9

ACETIC ACID AND A BUFFER  

DEFF Research Database (Denmark)

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.

Bjarnsholt, Thomas Technical University of Denmark,

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A novel fermentation strategy for removing the key inhibitor acetic acid and efficiently utilizing the mixed sugars from lignocellulosic hydrolysates  

Energy Technology Data Exchange (ETDEWEB)

As part of preliminary research efforts, we have completed several experiments which demonstrate 'proof of concept.' These experiments addressed the following three questions: (1) Can a synthetic mixed sugar solution of glucose and xylose be efficiently consumed using the multi-organism approach? (2) Can this approach be used to accumulate a model product? (3) Can this approach be applied to the removal of an inhibitor, acetate, selectively from mixtures of xylose and glucose? To answer the question of whether this multi-organism approach can effectively consume synthetic mixed sugar solutions, we first tested substrate-selective uptake using two strains, one unable to consume glucose and one unable to consume xylose. The xylose-selective strain ALS998 has mutations in the three genes involved in glucose uptake, rendering it unable to consume glucose: ptsG codes for the Enzyme IICB{sup Glc} of the phosphotransferase system (PTS) for carbohydrate transport (Postma et al., 1993), manZ codes for the IID{sup Man} domain of the mannose PTS permease (Huber, 1996), glk codes for glucokinase (Curtis and Epstein 1975) We also constructed strain ALS1008 which has a knockout in the xylA gene encoding for xylose isomerase, rendering ALS1008 unable to consume xylose. Two batch experiments and one continuous bioprocess were completed. In the first experiment, each strain was grown separately in a defined medium of 8 g/L xylose and 15 g/L glucose which represented xylose and glucose concentrations that can be generated by actual biomass. In the second experiment, the two strains were grown together in batch in the same defined, mixed-sugar medium. In a third experiment, we grew the strains continuously in a 'chemostat', except that we shifted the concentrations of glucose and xylose periodically to observe how the system would respond. (For example, we shifted the glucose concentration suddenly from 15 g/L to 30 g/L in the feed).

Mark A. Eiteman PHD; Elliot Altman Phd

2009-02-11

11

21 CFR 184.1005 - Acetic acid.  

Science.gov (United States)

...Substances Affirmed as GRAS § 184.1005 Acetic acid. (a) Acetic acid (C2 H4 O2 , CAS Reg. No. 64-19-7...phase oxidation of butane, and reaction of carbon monoxide with methanol derived from natural gas....

2010-04-01

12

Electron transfer induced fragmentation of acetic acid  

Science.gov (United States)

We present negative ion formation driven by electron transfer in atom (K) molecule (acetic acid) collisions. Acetic acid has been found in the interstellar medium, is also considered a biological related compound and as such studying low energy electron interactions will bring new insights as far as induced chemistry is concerned.

Ferreira da Silva, F.; Meneses, G.; Almeida, D.; Limão-Vieira, P.

2014-04-01

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Acetic acid mediated interactions between alumina surfaces  

Science.gov (United States)

Low-molecular-weight organic acids have been known to modify colloidal stability of alumina-based suspensions. We investigated interaction forces between alumina surfaces mediated by acetic acid which is one of the simplest organic acids. Forces between alumina surfaces were measured using the colloid-probe method of atomic force microscope (AFM). Repulsive forces attributed to steric repulsion due to adsorbed molecules and electrostatic repulsion dominated the interaction. Results of rheological characterization of the alumina slurry containing acetic acid supported the finding.

Sato, Kimiyasu; Y?lmaz, Hüseyin; Ijuin, Atsuko; Hotta, Yuji; Watari, Koji

2012-02-01

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Isolation of acetic acid bacteria from honey  

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Full Text Available Four thermotolerant acetic acid bacteria designated as CMU1, CMU2, CMU3 and CMU4 were isolated from six honey samples produced by three native bee species in northern Thailand, namely the dwarf honey bee (Apis florea, Asian honey bee (A. cerena and giant honey bee (A. dorsata. All isolates were tested for their tolerance to acetic acid and ethanol at 30?C and 37?C. It was found that they grew only in a medium containing 1% (v/v acetic acid at 30?C. However, isolate CMU4 showed the highest toleration to ethanol, viz. 10% (v/v and 9% (v/v at 30?C and 37?C respectively. Morphological and biochemical examination indicated that all isolates were members of the genus Gluconobacter.

Wasu Pathom-aree

2009-02-01

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Study of manganese and cadmium acetates solvation in hexane-acetic acid solutions by slubility method  

International Nuclear Information System (INIS)

Solubility of manganese (2) and cadmium (2) acetates in binary solvent acetic acid-hexane is measured at 298.15 K. Depending on the acetic acid concentration (cHAc) solubility value (S) of cadmium salt is determined by the equation: lgSCdAc2=-5.50+2.91 cHAc(cHAc=0.55-1 mole parts). Cadmium acetate during dissolving binds on the average 5.6 acetic acid molecules

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Hydrogen production by fermentation using acetic acid and lactic acid.  

Science.gov (United States)

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. PMID:17434426

Matsumoto, Mitsufumi; Nishimura, Yasuhiko

2007-03-01

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Kinetics of Ethyl Acetate Synthesis Catalyzed by Acidic Resins  

Science.gov (United States)

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…

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

2011-01-01

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KRAFT MILL BIOREFINERY TO PRODUCE ACETIC ACID AND ETHANOL: TECHNICAL ECONOMIC ANALYSIS  

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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 “...

Haibo Mao; Genco, Joseph M.; Adriaan van Heiningen; Hemant Pendse

2010-01-01

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Complexing of hafnium tetrafluoride in acetic acid  

International Nuclear Information System (INIS)

The process of hafnium tetrafluoride complexing with potassium fluoride in the media of waterless acetic acid, is investigated. Concentration regions of the potassium fluorohafnates formation are established. The methods of chemical and X-ray diffraction analyses have been used to study the separated KHfF5xCH3COOH, k2HfF6. Investigation of thermal stability of the KHfF5xCH3COOH solvate shows, that CH3COOH molecule splitting off takes place at 108 deg

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Rapid Economic, Acetic Acid, Papanicolaou Stain (REAP -  

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Full Text Available The universal stain for cervical cytological screening is Papanicolaou stain which has been used in different laboratories with many modifications. Aims: The study is designed to search for a superior and improved qualitative staining technique which is cheaper but rapid in cancer screening by cytology. The modified technique is referred as Rapid, economic, acetic acid Papanicolaou stain (REAP.Material & methods: 220 PAP smears from 110 patients ( 2 per subject were collected . One set of smears was stained by conventional Papanicolaou stain & the other set by REAP stain. Pre- Orange G 6 & post- Orange G 6 and post- EA50 ethanol baths in REAP stain were replaced by 1% acetic acid. Tap water was used instead of Scott’s tap water to reduce cost. Hematoxylin was preheated in waterbath to 60? C before staining for rapid penetration. Methanol was used for final dehydration. Results: The two methods were compared in respect of optimal cytoplasmic & nuclear staining, stain preservation, cost & total time for the procedure. In REAP technique, cytoplasmic & nuclear staining was optimal in 100 & 105 cases respectively. The cost was reduced to 25% due to limited alcohol use. The staining-time was minimised to 3 minutes. Conclusion: REAP stain, in comparison to conventional Papanicolaou, provides a suitable, excellent & rapid alternative for cytological screening with minimum cost. The stain preservation is also good in REAP method.

Ranu RoyBiswas

2008-12-01

 
 
 
 
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Ternary Phase Equilibrium Data for Acetic Acid-Water-Solvent Systems and Separation of Acetic Acid from Aqueous Solution  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Ternary phase equilibrium data for acetic acid with water and solvent (n-butyl alcohol, isobutyl alcohol and amyl alcohol) are presented and used to evaluate the possibility of employing distribution of acetic acid between water and these alcohols as a means of separation of acetic acid from its aqueous solution. Mutual solubility curves, tie-line data, distribution coefficient, selectivity diagrams and separation factor data were determined for these systems. From these data it has been conc...

Roy, Bhupesh C.; Kabir, M. J.; Rahman, M. S.

2005-01-01

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

Science.gov (United States)

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.

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

1988-01-01

23

Micelles Protect and Concentrate Activated Acetic Acid  

Science.gov (United States)

As more and more exoplanets are discovered and the habitability of such planets is considered, one can turn to searching for the origin of life on Earth in order to better understand what makes a habitable planet. Activated acetic acid, or methyl thioacetate, has been proposed to be central to the origin of life on Earth, and also as an important energy currency molecule in early cellular evolution. We have investigated the hydrolysis of methyl thioacetate under various conditions. Its uncatalyzed rate of hydrolysis is about three orders of magnitude faster (K = 0.00663 s^-1; 100°C, pH 7.5, concentration = 0.33mM) than published rates for its catalyzed production making it unlikely to accumulate under prebiotic conditions. However, we also observed that methyl thioacetate was protected from hydrolysis when inside its own hydrophobic droplets. We found that methyl thioacetate protection from hydrolysis was also possible in droplets of hexane and in the membranes of nonanoic acid micelles. Thus, the hydrophobic regions of prebiotic micelles and early cell membranes could have offered a refuge for this energetic molecule increasing its lifetime in close proximity to the reactions for which it would be needed. Methyl thioacetate could thus be important for the origin of life on Earth and perhaps for better understanding the potential habitability of other planets.

Todd, Zoe; House, C.

2014-01-01

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

Science.gov (United States)

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.

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

1986-01-01

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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)

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.

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

1984-01-01

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Structure of trimethylsilyl derivatives of acetic acid hydrazides  

Energy Technology Data Exchange (ETDEWEB)

The authors use NMR spectroscopy to study mono-and bistrimethylsilyl derivatives of N'-methyl- and N',N'-dimethylhydrazides of acetic acid. Two isomers in mobile equilibrium are found for both compounds in the temperature range from -80 to +100 C. It is shown that the trimethylsilylated N',N'-dimethylhydrazide of acetic acid is an equilibrium mixture of the syn and anti isomers of the hydrazone form, while the N,N'-bistrimethylsilyl-N'-methylhydrazide of acetic acid exists as an equilibrium mixture of N and O isomers.

Kalikhman, I.D.; Bannikova, O.B.; Ioffe, S.L.; Kalinin, A.V.; Khasapov, B.N.

1985-08-20

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

Science.gov (United States)

... 5-Hydroxyindole acetic acid/serotonin test system. 862.1390 Section... 5-Hydroxyindole acetic acid/serotonin test system. (a) Identification...A 5-hydroxyindole acetic acid/serotonin test system is a device...

2010-04-01

28

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

Science.gov (United States)

...2010-04-01 false 5-Hydroxyindole acetic acid/serotonin test system. 862...Systems § 862.1390 5-Hydroxyindole acetic acid/serotonin test system. (a) Identification. A 5-hydroxyindole acetic acid/serotonin test system is a...

2010-04-01

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Properties of MgB2 superconductor chemically treated by acetic acid  

International Nuclear Information System (INIS)

Commercial Alfa Aesar MgB2 powder was chemically treated by acetic acid with the aim of MgO removing. Single-core MgB2/Fe ex situ wires have been made by powder-in-tube (PIT) process using the powders treated with different acid concentration. All samples were annealed in argon at 950 deg. C/0.5 h. Differences in transition temperatures and critical currents of acetic acid treated MgB2 are related to the normal state resistivity, effective carbon substitution from the organic solvent and the active area fraction (grain-connectivity).

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

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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.

B. A. Mandagarán

2006-03-01

31

Recovery of Acetic Acid From Effluent via Freeze Crystallization  

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Full Text Available Freeze crystallization is an efficient separation process that can potentially be used in any application. Freeze crystallization is a high energy efficiency separation process that can be applied to a wide variety of industrial requirements. Although the vapor-liquid equilibrium is generally employed to separate the components of a solution, use of solid-liquid equilibrium should be considered – it may be cheaper. This paper describes a case study of recovery of acetic acid from effluent via freeze crystallization. Complete recovery of acetic acid from acetic acid-water solution by ordinary distillation is nearly impossible, because relative volatility of this mixture in the range of 1-30% of acetic acid in water is very close to one. But the same separation is possible by freeze separation technique and it is found experimentally that large amount of acetic acid (about 71.5% can be recovered via freeze separation technique. Also it is found that the energy required for recovery of acetic acid is much lower (about 24 times than that of distillation.

Tarak C. Padhiyar, Prof. Suchen B. Thakore

2013-04-01

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Study of alkaline-earth element complexes in anhydrous acetic acid  

International Nuclear Information System (INIS)

We have studied the complexes of alkaline-earth elements in anhydrous acetic acid. Using glass-electrode potentiometry we have studied the titration of alkaline earth acetates with perchloric acid which is the strongest acid in anhydrous acetic acid. These titrations have shown that the basic strength of these acetates increases as follows: Mg 4); the mixed acetate-acid sulfate complex of barium: Ba (OAc)(HSO4); the mixed acetate-chloride of barium: Ba (OAc)(Cl). (author)

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Ternary Phase Equilibrium Data for Acetic Acid-Water-Solvent Systems and Separation of Acetic Acid from Aqueous Solution  

Directory of Open Access Journals (Sweden)

Full Text Available Ternary phase equilibrium data for acetic acid with water and solvent (n-butyl alcohol, isobutyl alcohol and amyl alcohol are presented and used to evaluate the possibility of employing distribution of acetic acid between water and these alcohols as a means of separation of acetic acid from its aqueous solution. Mutual solubility curves, tie-line data, distribution coefficient, selectivity diagrams and separation factor data were determined for these systems. From these data it has been concluded that of these solvents amyl alcohol offers the best hope of achieving separation of acetic acid by distribution between amyl alcohol and water as it has the highest separation factor value than those of other two alcohols.

Bhupesh C. Roy

2005-01-01

34

Plasmacatalytic removal of lead acetate assisted by precipitation.  

Science.gov (United States)

The Gliding Arc Discharge (GAD) is an efficient non-thermal plasma technique able to degrade organic compounds dispersed in water at atmospheric pressure. The degradation of the organometallic lead acetate (PbAc) in aqueous solution was performed by two distinct plasmageneous processes: GAD and GAD/TiO2. The global oxidation of the organic matter was followed by Chemical Oxygen Demand (COD) and the mineralization was determined by the Total Organic Carbon (TOC). The Pb(2+) ions released during the degradation process were measured by Atomic Absorption Spectroscopy (AAS). For 2h of GAD treatment, the degradation rate of PbAc (10mM) reached 83% and for the same duration of GAD/TiO2 process ([TiO2]=1gL(-1)), it reached 93%. The release of Pb(2+) ions in the solution was respectively of 95% and 57% for GAD and GAD/TiO2 processes. The released Pb(2+) ions were removed by precipitation process in a basic medium at pH=11.1. A reaction mechanism was proposed to explain the PbAc molecule degradation and the Pb(2+) elimination. PMID:24462087

Haddou, Nabila; Ghezzar, Mouffok Redouane; Abdelmalek, Fatiha; Ognier, Stéphanie; Martel, Marc; Addou, Ahmed

2014-07-01

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Tetrazole acetic acid: Tautomers, conformers, and isomerization  

Science.gov (United States)

Monomers of (tetrazol-5-yl)-acetic acid (TAA) were obtained by sublimation of the crystalline compound and the resulting vapors were isolated in cryogenic nitrogen matrices at 13 K. The conformational and tautomeric composition of TAA in the matrix was characterized by infrared spectroscopy and vibrational calculations carried out at the B3LYP/6-311++G(d,p) level. TAA may adopt two tautomeric modifications, 1H- and 2H-, depending on the position of the annular hydrogen atom. Two-dimensional potential energy surfaces (PESs) of TAA were theoretically calculated at the MP2/6-311++G(d,p) level, for each tautomer. Four and six symmetry-unique minima were located on these PESs, for 1H- and 2H-TAA, respectively. The energetics of the detected minima was subsequently refined by calculations at the QCISD level. Two 1H- and three 2H-conformers fall within the 0-8 kJ mol-1 energy range and should be appreciably populated at the sublimation temperature (˜330 K). Observation of only one conformer for each tautomer (1ccc and 2pcc) is explained in terms of calculated barriers to conformational rearrangements. All conformers with the cis O=COH moiety are separated by low barriers (less than 10 kJ mol-1) and collapse to the most stable 1ccc (1H-) and 2pcc (2H-) forms during deposition of the matrix. On the trans O=COH surfaces, the relative energies are very high (between 12 and 27 kJ mol-1). The trans forms are not thermally populated at the sublimation conditions and were not detected in matrices. One high-energy form in each tautomer, 1cct (1H-) and 2pct (2H-), was found to differ from the most stable form only by rotation of the OH group and separated from other forms by high barriers. This opened a perspective for their stabilization in a matrix. 1cct and 2pct were generated in the matrices selectively by means of narrow-band near-infrared (NIR) irradiations of the samples at 6920 and 6937 cm-1, where the first OH stretching overtone vibrations of 1ccc and 2pcc occur. The reverse transformations could be induced by irradiations at 7010 and 7030 cm-1, transforming 1cct and 2pct back to 1ccc and 2pcc, also selectively. Besides the NIR-induced transformations, the photogenerated 1cct and 2pct forms also decay in N2 matrices back to 1ccc and 2pcc spontaneously, with characteristic decay times of hours (1H) and tens of minutes (2H). The decay mechanism is rationalized in terms of the proton tunneling. In crystals, TAA exists exclusively as 1H-tautomer. By contrast, the tautomeric composition of the matrix-isolated monomers was found to consist of both 1H- and 2H-tautomers, in comparable amounts. A mechanistic discussion of the tautomerization process occurring during sublimation, accounting also for the observed minor decomposition of TAA leading to CO2 and 5-methyl-tetrazole, is proposed.

Araujo-Andrade, C.; Reva, I.; Fausto, R.

2014-02-01

36

Investigation of hafnium acetate complexing with potassium fluoride in anhydrous acetic acid  

International Nuclear Information System (INIS)

Using hafnium tetraacetate as initial component an attempt is made to clarify the effect of anion on the complexing and possibility of tetraacetate solvation procedure in the medium of non-aqueous solvents. Hafnium tetraacetate and acetic acid form solvate complexes Hf(CH3COO)4 x 7CH3COOH and Hf(CH3COO)4 x 10CH3COOH at the expense of donor - acceptor interaction. Hafnium tetraacetate and potassium fluoride in anhydrous acetic acid form the complexes KF x Hf(CH3COO)4 and KF x Hf(CH3COO)4 x 5CH3COOH

37

Synthesis of imidazol-1-yl-acetic acid hydrochloride: A key intermediate for zoledronic acid  

Directory of Open Access Journals (Sweden)

Full Text Available A convenient and practical synthesis of imidazol-1-yl-acetic acid hydrochloride was achieved via N-alkylation of imidazole using tert-butyl chloroacetate followed by a non-aqueous ester cleavage of the resulting imidazol-1-yl-acetic acid tert-butyl ester in the presence of titanium tetrachloride. The synthesized imidazol-1-yl-acetic acid hydrochloride was then utilized to prepare zoledronic acid.

2008-11-01

38

Additive effects of acetic acid upon hydrothermal reaction of amylopectin  

International Nuclear Information System (INIS)

It is well known that over 0.8 kg kg?1 of starch is consisted of amylopectin (AP). In this study, production of glucose for raw material of ethanol by hydrothermal reaction of AP as one of the model compound of food is discussed. Further, additive effects of acetic acid upon hydrothermal reactions of AP are also investigated. During hydrothermal reaction of AP, production of glucose occurred above 453 K, and the glucose yield increased to 0.48 kg kg?1 at 473 K. Upon hydrothermal reaction of AP at 473 K, prolongation of the holding time was not effective for the increase of the glucose yield. Upon hydrothermal reaction of AP at 473 K for 0 s, the glucose yield increased significantly by addition between 0.26 mol L?1 and 0.52 mol L?1 of acetic acid. However, the glucose yield decreased and the yield of the other constituents increased with the increases of concentration of acetic acid from 0.65 mol L?1 to 3.33 mol L?1. It was considered that hydrolysis of AP to yield glucose was enhanced due to the increase of the amount of proton derived from acetic acid during hydrothermal reaction with 0.52 mol L?1 of acetic acid. -- Highlights: ? Glucose production by hydrothermal reaction of amylopectin (AP) at 473 K. ? Glucose yield increased to 0.48 kg kg-1 at 473 K. ? Prolongation of holding time was not effective for glucose yield. ? Glucose yield increased significantly by acetic acid (0.26–0.52 mol L-1) addition. ? Hydrolysis of AP to glucose was enhanced due to increase of proton from acetic acid.

39

CO2 Corrosion Mechanism of Carbon Steel in the Presence of Acetate and Acetic Acid  

International Nuclear Information System (INIS)

The corrosion behavior of carbon steel (N80) in carbon dioxide saturated 1%NaCl solution with and without acetic acid or acetate was investigated by weight-loss test, electrochemical methods (polarization curve, Electrochemical impedance spectroscopy). The major objective is to make clear that the effect of acetic acid and acetate on the corrosion of carbon steel in CO2 environments. The results indicate that either acetic acid or acetate accelerates cathodic reducing reaction, facilitates dissolution of corrosion products on carbon steel, and so promotes the corrosion rate of carbon steel in carbon dioxide saturated NaCl solution. All Nyquist Plots are consisting of a capacitive loop in high frequency region, an inductive loop in medial frequency region and a capacitive arc in low frequency region. The high frequency capacitive loop, medial frequency inductive loop and low frequency capacitive arc are corresponding to the electron transfer reaction, the formation/adsorption of intermediates and dissolution of corrosion products respectively. All arc of the measured impedance reduced with the increase of the concentration of Ac-, especially HAc. However, the same phenomenon is not notable after reducing pH value by adding HCI. HAc is a stronger proton donor and can be reduced directly by electrochemical reaction firstly. Ac- can't participate in electrochemistry reaction directly, but Ac- an hydrate easily to create HAc in carbon dioxide saturated environme HAc in carbon dioxide saturated environments. HAc is as catalyst in CO2 corrosion. As a result, the corrosion rate was accelerated in the presence of acetate ion even pH value of solution increased

40

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

Science.gov (United States)

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)

Forster, Denis; DeKleva, Thomas W.

1986-01-01

 
 
 
 
41

CARCINOGENICITY OF THE CHLORINATED ACETIC ACIDS  

Science.gov (United States)

Dichloroacetic Acid (DCAA) and trichloroacetic acid (TCAA) comprise a major fraction of the reaction products formed when water containing a variety of precursor humic materials is chlorinated. Both DCAA and TCAA administered in the drinking water increased the incidence of hepat...

42

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

DEFF Research Database (Denmark)

Some strains of Bradyrhizobium japonicum have the ability to catabolize indole-3-acetic acid. Indoleacetic acid (IAA), 4-chloro-IAA (4-Cl-IAA), and 5-Cl-IAA were metabolized to different extents by strains 61A24 and 110. Metabolites were isolated and analyzed by high-performance liquid 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

Jensen, J B; Egsgaard, H

1995-01-01

43

Acetic acid production from marine algae. Progress report No. 3, January 1, 1978--March 31, 1978  

Energy Technology Data Exchange (ETDEWEB)

The program for acetic acid production from marine algae has made significant progress in the current quarter. Some of the significant developments during this period are: (1) conversion of the available reducing equivalents in Chondrus crispus to organic acids has been carried to better than 80% completion; (2) thermophilic fermentations produce higher ratios of acetic acid to total acid than is the case for mesophilic fermentations (80% vs. 50%); (3) a membrane extraction process for removing organic acid products has been developed which has potential for commercial use; (4) a large scale fermentation was shown to convert over 50% of the available carbon in five days; (5) a reducing equivalents balance on the large scale fermentation was closed to with 96% of theoretical.

Sanderson, J.E.; Wise, D.L.

1978-06-01

44

Molecular Interactions in Binary Mixture of Polymethylmethacrylate with Acetic Acid  

Directory of Open Access Journals (Sweden)

Full Text Available Solution is prepared by mixing Polymethylmethacrylate in solid form with acetic acid, which at differentconcentration were used to measure density, viscosity & ultrasonic velocity in the temperature range 300C-650C,using ultrasonic interferometer at 1MHz. Using these measured values of density, viscosity & sound velocity,different parameters like, adiabatic compressibility, acoustic impedance and relaxation time have been measuredfor solution of polymethylmethacrylate with acetic acid under different conditions of temperature andconcentration. Variations of above parameters with respect to temperature and concentration have beendiscussed in terms of molecular interactions.

Richa Saxena

2010-07-01

45

First Acetic Acid Survey with CARMA in Hot Molecular Cores  

CERN Document Server

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...

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

2010-01-01

46

Intramolecular carbon isotope distribution of acetic acid in vinegar.  

Science.gov (United States)

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 (?(13)C(carboxyl) - ?(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. PMID:21830825

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

2011-09-14

47

Corrosion resistance of zirconium alloys in acetic acid environment  

International Nuclear Information System (INIS)

Studies on corrosion resistance of E100 (1%Nb) and E125(2.5%Nb) zirconium alloys and their welded joints in acetic acid media are carried out. The study results show that zirconium alloys are characterized by sufficiently good corrosion resistance. Insignificant corrosion of general character is identified in welded joints. 1 ref

48

The nitration of canrenone with acetic anhydride/nitric acid.  

Science.gov (United States)

3-Oxo-17 alpha-pregna-4,6-diene-21,17-carbolactone (canrenone, II) is produced from the potassium salt of 17-hydroxy-3-oxo-17 alpha-pregna-4,6-diene-21-carboxylic acid (I) by acid catalyzed lactonization. II reacts with acetic anhydride/nitric acid to give one main product (III) and some minor products. The structure of III was determined by chemical and spectral analysis to the 4-nitro derivative of canrenone. This result is in contrast to the known reactions of II with most other reagents that were found to add at delta(6), and also in contrast to the reactions of acetic anhydride/nitric acid with alkenes. Electrophilic substitution at the ambident C4 is discussed as the reaction path. The 4-nitro group enhances the inhibitory activity of II against Na+/K(+)-ATPase, the target enzyme of the cardioactive digitalis glycosides, which appears to indicate increased cardioactivity. PMID:9434341

Megges, R; Weiland, J; Undeutsch, B; Büchting, H; Schön, R

1997-12-01

49

KRAFT MILL BIOREFINERY TO PRODUCE ACETIC ACID AND ETHANOL: TECHNICAL ECONOMIC ANALYSIS  

Directory of Open Access Journals (Sweden)

Full Text Available 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 neutral hemicellulose extraction process” that uses the minimal amount of green liquor to maximize sugar production while still maintaining the strength quality of the final kraft pulp. Production rates vary between 2.4 to 6.6 million gallons per year of acetic acid and 1.0 and 5.6 million gallons per year of ethanol, depending upon the pulp production rate. The discounted cash flow rate of return for the process is a strong function of plant size, and the capital investment depends on the complexity of the process. For a 1,000 ton per day pulp mill, the production cost for ethanol was estimated to vary between $1.63 and $2.07/gallon, and for acetic acid between $1.98 and $2.75 per gallon depending upon the capital equipment requirements for the new process. To make the process economically attractive, for smaller mill sizes the processing must be simplified to facilitate reductions in capital cost.

Haibo Mao

2010-05-01

50

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

Science.gov (United States)

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.

Lewer, P.; Bandurski, R. S.

1987-01-01

51

Acetic acid denaturing for RNA capillary polymer electrophoresis.  

Science.gov (United States)

A strong denaturant to cleave intramolecular hydrogen bonds in RNA is required for RNA size separation in a small sample volume (acids were strong denaturants for RNA and the RNA separation performance was dramatically improved by capillary electrophoresis with a sieving matrix containing acetic acid. We revealed that the denaturing ability of 2.0 M acetic acid was stronger than that of either 2.5 M formaldehyde or 7.0 M urea by estimating DNA melting temperature. Consequently, we suggested "in-capillary denaturing polymer electrophoresis" as the RNA size separation methodology to simultaneously denature and separate RNA in a small sample volume without conventional in vitro sample preparation before electrophoresis. The baseline separation of RNA with a size of 100-10,000 nt was achieved in 25 min by "in-capillary denaturing polymer electrophoresis" with the running buffer containing 2.0 M acetic acid. The resolution and the theoretical plates of RNA separation peaks were larger than those of the RNA separation in a conventional CGE with in vitro sample preparation by 7.0 M urea. In addition, we detected RNA peaks from the nucleic acids extracted from NIH 3T3 cells without DNase enzyme treatment. PMID:19340827

Sumitomo, Keiko; Sasaki, Motoyasu; Yamaguchi, Yoshinori

2009-05-01

52

[Conversion of acetic acid to methane by thermophiles  

Energy Technology Data Exchange (ETDEWEB)

The primary goal of this project is to obtain a better understanding of thermophilic microorganisms which convert acetic acid to CH[sub 4]. The previous funding period represents a departure from earlier research in this laboratory, which was more physiological and ecological. The present work is centered on the biochemistry of the thermophile Methanothrix sp. strain CALS-1. this organism presents a unique opportunity, with its purity and relatively rapid growth, to do comparative biochemical studies with the other major acetotrophic genus Methanosarcina. We previously found that Methanothrix is capable of using acetate at concentrations 100 fold lower than Methanosarcina. This finding suggests that there are significant differences in the pathways of methanogenesis from acetate in the two genera.

Zinder, S.H.

1993-01-01

53

Effect of acetic acid on xylose conversion to ethanol by genetically engineered E. coli.  

Science.gov (United States)

Efficient utilization of the pentosan fraction of hemicellulose from lignocellulosic feedstocks offers an opportunity to increase the yield and to reduce the cost of producing fuel ethanol. During prehydrolysis (acid hydrolysis or autohydrolysis of hemicellulose), acetic acid is formed as a consequence of the deacetylation of the acetylated moiety of hemicellulose. Recombinant Escherichia coli B (ATCC 11303), carrying the plasmid pLO1297 with pyruvate decarboxylase and alcohol dehydrogenase II genes from Zymomonas mobilis (CP4), converts xylose to ethanol with a product yield that approaches theoretical maximum. Although other pentose-utilizing microorganisms are inhibited by acetic acid, the recombinant E. coli displays a high tolerance for acetic acid. In xylose fermentations with a synthetic medium (Luria broth), where the pH was controlled at 7, neither yield nor productivity was affected by the addition of 10.7 g/L acetic acid. Nutrient-supplemented, hardwood (aspen) hemicellulose hydrolysate (40.7 g/L xylose) was completely fermented to ethanol (16.3 g/L) in 98 h. When the acetic acid concentration was reduced from 5.6 to 0.8 g/L, the fermentation time decreased to 58 h. Overliming, with Ca(OH)2 to pH 10, followed by neutralization to pH 7 with sulfuric acid and removal of insolubles, resulted in a twofold increase in volumetric productivity. The maximum productivity was 0.93 g/L/h. The xylose-to-ethanol conversion efficiency and productivity in Ca(OH)2-treated hardwood prehydrolysate, fortified with only mineral salts, were 94% and 0.26 g/L/h, respectively. The recombinant E. coli exhibits a xylose-to-ethanol conversion efficiency that is superior to that of other pentose-utilizing yeasts currently being investigated for the production of fuel ethanol from lignocellulosic materials. PMID:1622203

Lawford, H G; Rousseau, J D

1992-01-01

54

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

Energy Technology Data Exchange (ETDEWEB)

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.

Zinder, S.

1991-01-01

55

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

Energy Technology Data Exchange (ETDEWEB)

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.

Zinder, S.

1991-12-31

56

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

Directory of Open Access Journals (Sweden)

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.

Ince E.

2002-01-01

57

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

E., Ince; S. Ismail, Kirbaslar.

58

On reaction of alkali metal hexafluorogermanates with acetic acid solutions  

International Nuclear Information System (INIS)

The behaviour of K2GeF6 and Cs2GeF6 has been studied in solutions of acetic acid. The solubility isotherm has been obtained in ternary system CH3COOH-K2GeF6-H2O and CH3COOH-Cs2GeF6-H2O and the composition of the solid phases has been determined. In the system CH3COOH-K2GeF6-H2O hexafluorogermanate of potassium is a solid phase; in the system CH3COOH-Cs2GeF6-H2O the solvate Cs2GeF6x2CH3COOH is formed. The similarity has been observed in interaction of alkali metal hexafluorogermanates with solutions of acetic acid and hydrogen fluoride

59

LIQUID-LIQUID EQUILIBRIA OF THE ACETIC ACID-WATER-MIXED SOLVENT (CYCLOHEXYL ACETATE-CYCLOHEXANOL SYSTEM  

Directory of Open Access Journals (Sweden)

Full Text Available Mixtures of cyclohexyl acetate and cyclohexanol were used as a mixed solvent to study liquid-liquid equilibria (LLE of the acetic acid-water-cyclohexanol-cyclohexyl acetate quaternary system. The solubility diagram and tie-line data were determined at 298±0.20 K and atmospheric pressure, using various compositions of mixed solvent. Reliability of the data was ascertained by making Othmer-Tobias and Hand plots.

Çehreli S.

2002-01-01

60

LIQUID-LIQUID EQUILIBRIA OF THE ACETIC ACID-WATER-MIXED SOLVENT (CYCLOHEXYL ACETATE-CYCLOHEXANOL) SYSTEM  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Mixtures of cyclohexyl acetate and cyclohexanol were used as a mixed solvent to study liquid-liquid equilibria (LLE) of the acetic acid-water-cyclohexanol-cyclohexyl acetate quaternary system. The solubility diagram and tie-line data were determined at 298±0.20 K and atmospheric pressure, using vari [...] ous compositions of mixed solvent. Reliability of the data was ascertained by making Othmer-Tobias and Hand plots.

S., Çehreli.

 
 
 
 
61

Characterisation of chitosan solubilised in aqueous formic and acetic acids  

Directory of Open Access Journals (Sweden)

Full Text Available The intrinsic viscosity of chitosan (MW 7.9 x 105 g mol-1 having a high degree of deacetylation and solubilised in aqueous formic and acetic acids was determined at room temperature. Contact angle and conductivity of the chitosan solutions were also studied. The values of critical coagulation concentration (CCC were then obtained from the plots of contact angle or conductivity versus concentration.

Esam A. El-hefian

2009-11-01

62

Electrochemistry of caffeic acid in acetate-ethanolic solutions  

Scientific Electronic Library Online (English)

Full Text Available SciELO Portugal | Language: English Abstract in english The electrochemical behaviour of caffeic acid in acetate solutions with and without added ethanol was studied by cyclic voltammetry. Solutions of pH and ethanol content close to the wine values (3.5 and 12%, respectively) were studied as a first model approach, pursuing work previously done. Studies [...] at pH 7.4 and different ionic strengths were also done. It was found that cyclic voltammograms of caffeic acid acetate ethanolic solutions had oxidation peak potential values (? 470 mV) at pH 3.5 irrespective of the previous excursions of potential with the same set of electrodes. However, the cathodic peaks potentials and currents strongly depended on the cyclic voltammogram of the corresponding solvent electrolyte which had previously been run. The separation of oxidation and reduction peak potentials evidenced the presence of dimmers of caffeic acid in solution, under the following conditions: 0.1 mol dm-3 acetate buffer pH 3.5 + 12% ethanol with the ionic strength increased by the addition of 0.05 mol dm-3 KCl; limits of the anodic potential: from -100 to + 700 mV and N2 bubbled through the solution for 10 minutes.

S.C., Mordido; M.J.F., Rebelo.

63

Acetic Acid bacteria: physiology and carbon sources oxidation.  

Science.gov (United States)

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. PMID:24426139

Mamlouk, Dhouha; Gullo, Maria

2013-12-01

64

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

Science.gov (United States)

...2010-07-01 2010-07-01 false Acetic acid; exemption from the requirement...Exemptions From Tolerances § 180.1258 Acetic acid; exemption from the requirement...for residues of the biochemical pesticide acetic acid when used as a...

2010-07-01

65

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

Science.gov (United States)

...2010-07-01 2010-07-01 false Acetic acid, [(5-chloro-8-quinolinyl...Specific Chemical Substances § 721.304 Acetic acid, [(5-chloro-8-quinolinyl...The chemical substance identified as acetic acid,...

2010-07-01

66

Indole-3-acetic acid in plant-microbe interactions.  

Science.gov (United States)

Indole-3-acetic acid (IAA) is an important phytohormone with the capacity to control plant development in both beneficial and deleterious ways. The ability to synthesize IAA is an attribute that many bacteria including both plant growth-promoters and phytopathogens possess. There are three main pathways through which IAA is synthesized; the indole-3-pyruvic acid, indole-3-acetamide and indole-3-acetonitrile pathways. This chapter reviews the factors that effect the production of this phytohormone, the role of IAA in bacterial physiology and in plant-microbe interactions including phytostimulation and phytopathogenesis. PMID:24445491

Duca, Daiana; Lorv, Janet; Patten, Cheryl L; Rose, David; Glick, Bernard R

2014-07-01

67

Distinct Effects of Sorbic Acid and Acetic Acid on the Electrophysiology and Metabolism of Bacillus subtilis.  

Science.gov (United States)

Sorbic acid and acetic acid are among the weak organic acid preservatives most commonly used to improve the microbiological stability of foods. They have similar pKa values, but sorbic acid is a far more potent preservative. Weak organic acids are most effective at low pH. Under these circumstances, they are assumed to diffuse across the membrane as neutral undissociated acids. We show here that the level of initial intracellular acidification depends on the concentration of undissociated acid and less on the nature of the acid. Recovery of the internal pH depends on the presence of an energy source, but acidification of the cytosol causes a decrease in glucose flux. Furthermore, sorbic acid is a more potent uncoupler of the membrane potential than acetic acid. Together these effects may also slow the rate of ATP synthesis significantly and may thus (partially) explain sorbic acid's effectiveness. PMID:25038097

van Beilen, J W A; Teixeira de Mattos, M J; Hellingwerf, K J; Brul, S

2014-10-01

68

Indole-3-acetic acid metabolism in normal and dwarf micropropagated banana plants (Musa spp. AAA  

Directory of Open Access Journals (Sweden)

Full Text Available Nanism is one of the most frequent type of mutant in micropropagated banana plants from the Cavendish subgroup. The present study aimed at studying some of the hormone factors involved in this type of mutation. Rhizomes from normal and dwarf plants from the cultivar Grand Naine were incubated for 5 d in the presence of [³H]-L-tryptophan, [³H]-indole-3-acetic acid and gibberellin, to quantify the endogenous levels of indole-3-acetic acid-ester, indole-3-acetic acid-amide, free indole-3-acetic acid, and cytokinins. The endogenous levels of indole-3-acetic acid and its ester- and amide-conjugated forms were measured in normal and dwarf plants incubated for 30 d with gibberellin, indole-3-acetic acid, and L- and D-tryptophan. In normal plants, the use of [³H]-L-tryptophan resulted in higher levels of radioactivity in the retention times corresponding to indole-3-acetic acid, indole-3-acetic acid-aspartate, indole-3-acetic acid-glycine and indole-3-acetic acid-alanine. These values were higher than those observed in dwarf plants. Higher quantities of radioactive indole-3-acetic acid and of amide-forms in dwarf plants occurred in rhizomes treated with [³H]-L-tryptophan and gibberellin simultaneously. The endogenous levels of total cytokinins were the same in both materials, while the levels of indole-3-acetic acid in normal plants were 1.5 times higher than in dwarf plants. Moreover, in these ones application of tryptophan and gibberellin coincided in an increase in the levels of free indole-3-acetic acid in dwarf plants and to a decrease in the levels of indole-3-acetic acid-ester and indole-3-acetic acid-amide.

Zaffari Gilmar Roberto

2002-01-01

69

Formation of biologically relevant carboxylic acids during the gamma irradiation of acetic acid  

Science.gov (United States)

Irradiation of aqueous solutions of acetic acid with gamma rays produced several carboxylic acids in small yield. Their identification was based on the technique of gas chromatography combined with mass spectrometry. Some of these acids are Krebs Cycle intermediates. Their simultaneous formation in experiments simulating the primitive conditions on the earth suggests that metabolic pathways may have had their origin in prebiotic chemical processes.

Negron-Mendoza, A.; Ponnamperuma, C.

1976-01-01

70

Dielectric relaxation of formic acid, acetic acid and their mixtures with some aliphatic alcohols  

Energy Technology Data Exchange (ETDEWEB)

The complex permittivity of the liquid systems ethanol/acetic acid, 1-butanol/acetic acid and 1-butanol/formic acid has been measured in the range between some MHz and 36 GHz at 20deg C. Fitting the results by a sum of three Debye type spectral components allows for a plausible assignment by assuming (I) ill defined, polar self and heteroassociates of higher order, (II) low order polar associates and (III) monomers and, in addition, (IV) dielectrically ineffective, essentially nonpolar low order associates. The latter species, which dominates in pure acetic acid but is of little importance in pure formic acid, is probably responsible for the differences in the relaxation behaviour of alcoholic mixtures containing one or the other of these acids. (orig.).

Getta, P.; Stockhausen, M.; Wessels, V. (Muenster Univ. (Germany, F.R.). Inst. fuer Physikalische Chemie)

1988-01-01

71

Simultaneous removal of sulfide, nitrate and acetate under denitrifying sulfide removal condition: Modeling and experimental validation  

International Nuclear Information System (INIS)

Graphical abstract: Model evaluation applied to case study 1: (A-G) S2?, NO3?-N, NO2?-N, and Ac?-C profiles under initial sulfide concentrations of 156.2 (A), 539 (B), 964 (C), 1490 (D), 342.7 (E), 718 (F), and 1140.7 (G) mg L?1. The solid line represents simulated result and scatter represents experimental result. -- Highlights: • This work developed a mathematical model for DSR process. • Kinetics of sulfur–nitrogen–carbon and interactions between denitrifiers were studied. • Kinetic parameters of the model were estimated via data fitting. • The model described kinetic behaviors of DSR processes over wide parametric range. -- Abstract: Simultaneous removal of sulfide (S2?), nitrate (NO3?) and acetate (Ac?) under denitrifying sulfide removal process (DSR) is a novel biological wastewater treatment process. This work developed a mathematical model to describe the kinetic behavior of sulfur–nitrogen–carbon and interactions between autotrophic denitrifiers and heterotrophic denitrifiers. The kinetic parameters of the model were estimated via data fitting considering the effects of initial S2? concentration, S2?/NO3?-N ratio and Ac?-C/NO3?-N ratio. Simulation supported that the heterotrophic denitratation step (NO3? reduction to NO2?) was inhibited by S2? compared with the denitritation step (NO2? reduction to N2). Also, the S2? oxidation by autotrophic denitrifiers was shown two times lower in rate with NO2? as electron acceptor than that with NO3? as electron acceptor. NO3? reduction by autotrophic denitrifiers occurs 3–10 times slower when S0 participates as final electron donor compared to the S2?-driven pathway. Model simulation on continuous-flow DSR reactor suggested that the adjustment of hydraulic retention time is an efficient way to make the reactor tolerating high S2? loadings. The proposed model properly described the kinetic behaviors of DSR processes over wide parametric ranges and which can offer engineers with basis to optimize bioreactor operation to improve the treatment capacity

72

Aerobic oxidation of aqueous ethanol using heterogeneous gold catalysts: Efficient routes to acetic acid and ethyl acetate  

DEFF Research Database (Denmark)

The aerobic oxidation of aqueous ethanol to produce acetic acid and ethyl acetate was studied using heterogeneous gold catalysts. Comparing the performance of Au/MgAl2O4 and Au/TiO2 showed that these two catalysts exhibited similar performance in the reaction. By proper selection of the reaction conditions, yields of 90-95% of acetic acid could be achieved at moderate temperatures and pressures. Based on our findings, a reaction pathway for the catalytic oxidation of ethanol via acetaldehyde to acetic acid is proposed, and the rate-determining step (RDS) in the mechanism is found to be the (possibly oxygen-assisted) dehydrogenation of ethanol to produce acetaldehyde. It also is concluded that most of the CO2 formed as a byproduct in the reaction results from the absorbed intermediate in the dehydrogenation of ethanol to produce acetaldehyde. By varying the amount of water in the reaction mixture, the possibilities for producing ethyl acetate by the aerobic oxidation of ethanol is also studied. At low ethanol concentrations, the main product is acetic acid; at concentrations >60 wt%, it is ethyl acetate.

JØrgensen, Betina; Christensen, Christina Hviid

2007-01-01

73

Dissolution of steelmaking slags in acetic acid for precipitated calcium carbonate production  

International Nuclear Information System (INIS)

A promising option for long-term storage of CO2 is to fixate carbon dioxide as magnesium- and calcium carbonates. Slags from iron and steel works are potential raw materials for carbonation due to their high contents of calcium silicates. Precipitated calcium carbonate (PCC) is used as filler and coating materials in paper. If slag could be used instead of limestone for producing PCC, considerable energy savings and carbon dioxide emissions reductions could be achieved. In this paper, the leaching of calcium from iron and steel slags using acetic acid was investigated. Thermodynamic equilibrium calculations at atmospheric gas pressures showed that extraction of calcium is exothermic and feasible at temperatures lower than 156 oC, while the precipitation of calcium carbonate is endothermic and feasible at temperatures above 45 oC. The formation of calcium- and magnesium acetate in the solution was found to be thermodynamically possible. Laboratory-scale batch experiments showed that iron and steel slags rapidly dissolve in acetic acid in a few minutes and the exothermic nature of the reaction was verified. While silicon was successfully removed by filtration using solution temperatures of 70-80 oC, further separation methods are required for removing iron, aluminum and magnesium from the solution

74

Uranyl complexes of ?-carboxypolymethylene-diaminetetra-acetic acids  

International Nuclear Information System (INIS)

The uranyl complexes of N,N,N',N'-tetrakis(carboxymethyl)-2,3-diaminopropionic acid, N,N,N',N'-tetrakis(carboxymethyl)diaminobutyric acid, N,N,N',N'-tetrakis(carboxymethyl)ornithine and N,N,N',N'-tetrakis(carboxymethyl)lysine have been studied by potentiometry, with computer evaluation of the titration data by the MINIQUAD program. Stability constants of the 1:1 and 2:1 metal:ligand chelates have been determined as well as the hydrolysis and polymerization constants at 250 in 0.1M potassium nitrate. Results are compared with those obtained for the uranyl complexes of the corresponding members of the series of the polymethylenediaminetetra-acetic acids. (author)

75

Probiotic and Acetic Acid Effect on Broiler Chickens Performance  

Directory of Open Access Journals (Sweden)

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.

Martin Král

2011-05-01

76

1-[3-(4-Nitrophenylpropanoyl]urea acetic acid monosolvate  

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Full Text Available The title compound, C10H11N3O4·C2H4O2, was prepared by an electrochemical technique. In the crystal, acetic acid molecules are involved in hydrogen bonding to two separate propanoylurea molecules, acting as a donor in an O—H...O interaction and as an acceptor in two N—H...O interactions. The propanoylurea molecules interact with each other via N—H...O hydrogen bonds. C—H...O interactions also stabilize the crystal structure.

Soraya Merzouki

2011-11-01

77

The highly tolerant acetic acid bacterium Gluconacetobacter europaeus adapts to the presence of acetic acid by changes in lipid composition, morphological properties and PQQ-dependent ADH expression.  

Science.gov (United States)

The strain of acetic acid bacterium, Gluconacetobacter europaeus V3, previously isolated from industrial vinegar-producing bioreactor, tolerates extremely high acetic acid concentrations of up to 10% (v/v). Increased concentration of acetic acid changed the total fatty acid composition of cells by increasing the concentration of a major unsaturated fatty acid, the cis-vaccenic acid. Among the phospholipids, the most significant change was observed for phosphatidylglycerol with 7.3-fold increase and phosphatidylethanolamin with 2.7-fold decrease in the presence of 3% (v/v) of acetic acid. The sizes of cells analyzed with scanning electron microscopy changed from short to long rods in the presence of acetic acid. The cells were covered with spongy layer. The increase of acetic acid concentration from 1 to 2% (v/v) induced the expression of PQQ-dependent alcohol dehydrogenase, but the regulation could not be demonstrated at the transcriptional level. All together, our results suggest that Ga. europaeus activates several adaptive mechanisms to resist the stress of acetic acid. PMID:17487444

Trcek, Janja; Jernejc, Katarina; Matsushita, Kazunobu

2007-07-01

78

Acetic acid production from marine algae. Progress report No. 4, April 1-June 30, 1978  

Energy Technology Data Exchange (ETDEWEB)

To date fermentations of marine algal species run at a controlled pH of 5.5 to 6.0 have exhibited essentially complete conversion to organic acids in as little as 16 days. (By complete conversion is meant conversion of each hexose unit to three acetic acid molecules or higher organic acids on a reducing equivalent basis.) As a result of these rapid rates and high conversions economic calculations have shown that processing costs are sufficiently low to encourage commercial development of this process. In the course of this work a diffusion membrane extraction system has been developed for removing organic acids from the fermentation broth. In addition, a fixed packed bed fermenter with a capacity of approximately 300 liters has been constructed and operated for a six month period. Another significant result is that fermentation at thermophilic temperatures (55/sup 0/C) gives higher ratios of acetic acid to total acid product than at mesophilic temperatures (37/sup 0/C). Manuscripts of two technical presentations based on this work are attached.

Sanderson, J. E.; Wise, D. L.

1978-08-28

79

Anaerobic Conversion of Lactic Acid to Acetic Acid and 1,2-Propanediol by Lactobacillus buchneri  

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The degradation of lactic acid under anoxic conditions was studied in several strains of Lactobacillus buchneri and in close relatives such as Lactobacillus parabuchneri, Lactobacillus kefir, and Lactobacillus hilgardii. Of these lactobacilli, L. buchneri and L. parabuchneri were able to degrade lactic acid under anoxic conditions, without requiring an external electron acceptor. Each mole of lactic acid was converted into approximately 0.5 mol of acetic acid, 0.5 mol of 1,2-propanediol, and ...

Elferink, S.; Krooneman, J.; Gottschal, J. C.; Spoelstra, S. F.; Faber, F.; Driehuis, F.

2001-01-01

80

Oxidation of indole-3-acetic acid to oxindole-3-acetic acid by etiolated and green corn tissues  

Energy Technology Data Exchange (ETDEWEB)

Etiolated corn tissues oxidase indole-3-acetic acid (IAA) to oxindole-3-acetic acid (OxIAA). This oxidation results in loss of auxin activity and may plant a role in regulating IAA-stimulated growth. The enzyme has been partially purified and characterized and shown to require O{sub 2}, and a heat-stable lipid-soluble corn factor which can be replaced by linolenic or linoleic acids in the oxidation of IAA. Corn oil was tested as a cofactor in the IAA oxidation reaction. Corn oil stimulated enzyme activity by 30% while trilinolein was inactive. The capacity of green tissue to oxidize IAA was examined by incubating leaf sections from 2 week old light-grown corn seedlings with {sup 14}C-IAA. OxIAA and IAA were separated from other IAA metabolites on a 3 ml anion exchange column. Of the IAA taken up by the sections, 13% was oxidized to OxIAA. This is the first evidence that green tissue of corn may also regulate IAA levels by oxidizing IAA to OxIAA.

Reinecke, D. (Michigan State Univ., East Lansing (USA))

1989-04-01

 
 
 
 
81

?-(Acetic acid-di-?-chlorido-bis[triphenyltellurium(IV] monohydrate  

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Full Text Available The asymmetric unit of the title compound, C38H34Cl2O2Te2·H2O, contains two independent TeIV cations, each coordinated by three phenyl ligands, two Cl? anions and one acetic acid molecule in a distorted octahedral C3Cl2O geometry; the longer Te...Cl distances ranging from 3.2007?(11 to 3.4407?(11?Å and the longer Te...O distances of 3.067?(3 and 3.113?(3?Å indicate the weak bridge coordination. The Cl? anion and acetic acid molecule bridge the two independent TeIV cations, forming the dimeric complex molecule, in which the Te...Te separation is 3.7314?(4?Å. In the crystal, the water molecules of crystallization link the TeIV complex molecules into chains running along the b-axis direction via O—H...O and O—H...Cl hydrogen bonds.

Feng Hu

2013-07-01

82

Transcript and metabolite alterations increase ganoderic acid content in Ganoderma lucidum using acetic acid as an inducer.  

Science.gov (United States)

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 ?g/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. PMID:25216642

Ren, Ang; Li, Xiong-Biao; Miao, Zhi-Gang; Shi, Liang; Jaing, Ai-Liang; Zhao, Ming-Wen

2014-12-01

83

Boswellic acid acetate induces apoptosis through caspase-mediated pathways in myeloid leukemia cells.  

Science.gov (United States)

The mechanism of the cytotoxic effect of boswellic acid acetate, a 1:1 mixture of alpha-boswellic acid acetate and beta-boswellic acid acetate, isolated from Boswellia carterri Birdw on myeloid leukemia cells was investigated in six human myeloid leukemia cell lines (NB4, SKNO-1, K562, U937, ML-1, and HL-60 cells). Morphologic and DNA fragmentation assays indicated that the cytotoxic effect of boswellic acid acetate was mediated by induction of apoptosis. More than 50% of the cells underwent apoptosis after treatment with 20 mug/mL boswellic acid for 24 hours. This apoptotic process was p53 independent. The levels of apoptosis-related proteins Bcl-2, Bax, and Bcl-XL were not modulated by boswellic acid acetate. Boswellic acid acetate induced Bid cleavage and decreased mitochondrial membrane potential without production of hydrogen peroxide. A general caspase inhibitor (Z-VAD-FMK) and a specific caspase-8 inhibitor II (Z-IETD-FMK) blocked boswellic acid acetate-induced apoptosis. The mRNAs of death receptors 4 and 5 (DR4 and DR5) were induced in leukemia cells undergoing apoptosis after boswellic acid acetate treatment. These data taken together suggest that boswellic acid acetate induces myeloid leukemia cell apoptosis through activation of caspase-8 by induced expression of DR4 and DR5, and that the activated caspase-8 either directly activates caspase-3 by cleavage or indirectly by cleaving Bid, which in turn decreases mitochondria membrane potential. PMID:15767547

Xia, Lijuan; Chen, Duo; Han, Rui; Fang, Qicheng; Waxman, Samuel; Jing, Yongkui

2005-03-01

84

Leaching of spent lead acid battery paste components by sodium citrate and acetic acid.  

Science.gov (United States)

A sustainable method, with minimal pollution and low energy cost in comparison with the conventional smelting methods, is proposed for treating components of spent lead-acid battery pastes in aqueous organic acid(s). In this study, PbO, PbO2, and PbSO4, the three major components in a spent lead paste, were individually reacted with a mixture of aqueous sodium citrate and acetic acid solution. Pure lead citrate precursor of Pb3(C6H5O7)2 · 3H2O is the only product crystallized in each leaching experiment. Conditions were optimized for individual lead compounds which were then used as the basis for leaching real industrial spent paste. In this work, efficient leaching process is achieved and raw material cost is reduced by using aqueous sodium citrate and acetic acid, instead of aqueous sodium citrate and citric acid as reported in a pioneering hydrometallurgical method earlier. Acetic acid is not only cheaper than citric acid but is also more effective in aiding dissolution of the lead compounds thus speeding up the leaching process in comparison with citric acid. Lead citrate is readily crystallized from the aqueous solution due to its low solubility and can be combusted to directly produce leady oxide as a precursor for making new battery pastes. PMID:23500418

Zhu, Xinfeng; He, Xiong; Yang, Jiakuan; Gao, Linxia; Liu, Jianwen; Yang, Danni; Sun, Xiaojuan; Zhang, Wei; Wang, Qin; Kumar, R Vasant

2013-04-15

85

Radioimmunoassays for serotonin and 5-hydroxyindole acetic acid  

International Nuclear Information System (INIS)

Radioimmunoassays for serotonin and 5-hydroxyindole acetic acid were developed. High titer antibodies, having a well-defined high specificity, have been raised by coupling the side-chain of both molecules to human serum albumin. Serotonin is first converted into N-hemisuccinate, and then treated like 5-HIAA, namely, conjugated with HSA for the immunogen. Synthesis of 125I iodinated analogues was performed by coupling 5-HIAA or N-succinyl serotonin to glycyltyrosine, without any contact between both molecules and the oxidizing reagents. Chemical conversions of biological samples (by succinylation for 5-HT and amidation for 5-HIAA) were carried out. This critical step makes the antigen molecules resemble the immunogen more closely, thus allowing an appreciable gain in specificity and sensitivity. These assays allow the rapid determination of 5-HT and 5-HIAA in small amounts of tissue, blood, cerebral spinal fluid or perfusate without any purification, with a sensitivity threshold of 50 pg

86

Anodic behavior of molybdenum in acetic acid solution  

International Nuclear Information System (INIS)

Polarization experiments were made in acetic acid solutions of pH 5 under potentiostatic and galvanostatic conditions. The passive region of molybdenum extended from -0.2 to -0.1 V (SCE) and transpassive dissolution occurred above -0.1 V. In the transpassive region, molybdenum dissolved as MoO42- via the formation of MoO(OH)2 or Mo(OH)4 film. The electric charges utilized in the formation of oxide film Q1 was determined by coulometry and that of its dissolution as MoO42-Q sub(d) by colorimetric analysis. The ratio Q1/(Q sub(d)+Q1) was found to be 0.7. The oxide film nature showed poor adhesion and black. It is considered highly probable that the oxide film is precipitated from the solution phase via a dissolution process. (author)

87

Radicals from the oxidation of acetic acid-2-hydroxyethylester  

International Nuclear Information System (INIS)

The ESR-spectra of free radicals formed by the reaction of OH radicals, tert.-butoxyl radicals and acetone triplets with acetic acid-2-hydroxy ethylester have been studied in different solvents. The three radicals expected from H-atom abstraction have been identified. Further the hyperfine splittings of four adducts are presented which are produced in secondary reactions. These radicals are formed by the addition of ?-oxoalkyl and of tert.-butoxyl radicals to enol intermediates. The OH splittings of these radicals have been resolved. The couplings are solvent dependent and pass through the value zero at certain temperatures. The unusually small ?-couplings, the well resolved epsilon-splittings, and the selective line broadenings are interpreted in terms of polarisation of the radical and a barrier for internal rotation. From the line broadening a barrier of >= 2.4 kcal mol-1 was obtained. Furthermore the polarisation of the radical might favour its heterolytic dissociation in polar solvents. (orig.)

88

Inflammatory cells' role in acetic acid-induced colitis  

Science.gov (United States)

Background: Free radicals are the known mechanisms responsible for inducing colitis with two origins: Inflammatory cells and tissues. Only the inflammatory cells can be controlled by corticosteroids. Our aim was to assess the importance of neutrophils as one of the inflammatory cells in inducing colitis and to evaluate the efficacy of corticosteroids in the treatment of inflammatory bowel disease (IBD). Materials and Methods: Thirty-six mice were divided into six groups of six mice each. Colitis was induced in three groups by exposing them to acetic acid through enema (group 1), ex vivo (group 3), and enema after immune suppression (group 5). Each group had one control group that was exposed to water injection instead of acetic acid. Tissue samples were evaluated and compared based on macroscopic damages and biochemical and pathological results. Results: Considering neutrophilic infiltration, there were significant differences between groups 1, 3, 5, and the control of group 1. Groups 3, 5, and their controls, and group 1 and the control of group 3 had significant differences in terms of goblet depletion. Based on tissue originated H2O2, we found significant differences between group 1 and its control and group 3, and also between groups 5 and the control of group 3. All the three groups were significantly different from their controls based on Ferric Reducing Ability of Plasma (FRAP) and such differences were also seen between group 1 with two other groups. Conclusion: Neutrophils may not be the only cause of oxidation process in colitis, and also makes the effectiveness of corticosteroids in the treatment of this disease doubtful. PMID:25337523

Sanei, Mohammad H.; Hadizadeh, Fatemeh; Adibi, Peyman; Alavi, Sayyed Ali

2014-01-01

89

CO{sub 2} Corrosion Mechanism of Carbon Steel in the Presence of Acetate and Acetic Acid  

Energy Technology Data Exchange (ETDEWEB)

The corrosion behavior of carbon steel (N80) in carbon dioxide saturated 1%NaCl solution with and without acetic acid or acetate was investigated by weight-loss test, electrochemical methods (polarization curve, Electrochemical impedance spectroscopy). The major objective is to make clear that the effect of acetic acid and acetate on the corrosion of carbon steel in CO{sub 2} environments. The results indicate that either acetic acid or acetate accelerates cathodic reducing reaction, facilitates dissolution of corrosion products on carbon steel, and so promotes the corrosion rate of carbon steel in carbon dioxide saturated NaCl solution. All Nyquist Plots are consisting of a capacitive loop in high frequency region, an inductive loop in medial frequency region and a capacitive arc in low frequency region. The high frequency capacitive loop, medial frequency inductive loop and low frequency capacitive arc are corresponding to the electron transfer reaction, the formation/adsorption of intermediates and dissolution of corrosion products respectively. All arc of the measured impedance reduced with the increase of the concentration of Ac-, especially HAc. However, the same phenomenon is not notable after reducing pH value by adding HCI. HAc is a stronger proton donor and can be reduced directly by electrochemical reaction firstly. Ac- can't participate in electrochemistry reaction directly, but Ac- an hydrate easily to create HAc in carbon dioxide saturated environments. HAc is as catalyst in CO{sub 2} corrosion. As a result, the corrosion rate was accelerated in the presence of acetate ion even pH value of solution increased

Liu, D.; Fu, C. Y.; Chen, Z. Y.; Guo, X. P. [Huazhong University of Science and Technology, Wuhan (China)

2007-10-15

90

Controlling hydrothermal reaction pathways to improve acetic acid production from carbohydrate biomass.  

Science.gov (United States)

A two-step hydrothermal process to improve the production of acetic acid was discussed. The first step was to accelerate the formation of 5-hydroxymethyl-2-furaldehyde (HMF), 2-furaldehyde (2-FA), and lactic acid (LA), and the second step was to further convert the furans (HMF, 2-FA) and LA produced in the first step to acetic acid by oxidation with newly supplied oxygen. The acetic acid obtained by the two-step process had not only a high yield but also better purity. The contribution of two pathways via furans and LA in the two-step process to convert carbohydrates into acetic acid was roughly estimated as 85-90%, and the ratio of the contributions of furans and LA to yield acetic acid was estimated as 2:1. The fact that WO of carbohydrates is not capable of producing a large amount of acetic acid, while the two-step process can enhance the acetic acid yield, can be explained because formic acid is a basic product of direct oxidation of carbohydrate, and acetic acid in WO of carbohydrates may come from the oxidation of dehydration products of aldose. PMID:15819253

Jin, Fangming; Zhou, Zhouyu; Moriya, Takehiko; Kishida, Hisanori; Higashijima, Hisao; Enomoto, Heiji

2005-03-15

91

Remedial methods for intergranular attack of alloy 600 tubing. Volume 3. Boric acid and acetic acid remedial methods. Final report  

International Nuclear Information System (INIS)

An important cause of recent tube degradation in recirculating pressurized water reactor (PWR) steam generators with open tube/tubesheet crevices is intergranular attack (IGA) of alloy 600 tubing in the crevice region. The attack appears to occur on the hot leg tubing because of high concentrations of caustic species formed from remnants of past phosphate water treatment, combined with materials from inleakage from freshwater-cooled condensers. The concept of using neutralizers to modify the aggressiveness of the crevice environment was examined. It appears that this can be accomplished by neutralizing the caustic species with an acid. Two ways to apply the acid are by off-line flushing during plant shutdown and by on-line treatment during operation. The substance that appears to be most suitable for off-line flushing is acetic acid, with boric acid as a second choice. Concentrations should be in the range of from 1000 to 5000 ppM. The addition of 1000 to 5000 ppM of a non-ionic detergent in the flush solution should improve penetration of the crevice. Use of preflush lancing to remove sludge on the tubesheet will also help by reducing acid consumption. The requirements for materials to be used in on-line treatment are more stringent because of possible interaction with other components in the secondry system. Boric acid is the only substance that has operational experience. A series of tests are proposed to investigate the behavior of acetic acid and boric acid on tubesheet sludge, on tubesheet/support plate material, and on alloy 600/tubesheet couples. Similarly, areas of uncertainty of on-line treatment with boric acid are its effect on tubesheet/support plate materials and on the rest of the secondary system. 23 refs

92

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

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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.

K Beheshti-Maal

2010-06-01

93

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

Science.gov (United States)

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. PMID:25328203

Subari?, Drago; A?kar, Dur?ica; Babi?, Jurislav; Saka?, Nikola; Jozinovi?, Antun

2014-10-01

94

Investigation of radiolytic gas formation in nitric acid and acetic acid solutions  

International Nuclear Information System (INIS)

Gas-formation processes by ?-radiolysis of aqueous solutions, containing HNO3, NaNO3 and CH3COOH are studied. H2, O2, N2, N2O, CO2 and CH4 are determined by chromatographic and spectrographic methods among the radiolysis products. It is shown that introduction of acetic acid into nitric acid solutions leads to essential increase in gas release and growth of radiation-chemical yield of nitrogen oxide

95

75 FR 40736 - Acetic Acid; Exemption from the Requirement of a Tolerance  

Science.gov (United States)

...for a pesticide chemical residue in or on a food) only if EPA...As an organic chemical, acetic acid...alcohol containing foods or liquids such...energy drinks (CODEX GSFA, 2009...Acetic Acid''. Codex General Standards for Food Additives...

2010-07-14

96

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 < 0.05 inhibitory effect on L. monocytogenes compared to control legs, with a decrease of about 1.31 log units after eight days of storage. Sensory quality was not adversely affected by 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.

Elena Gonzalez-Fandos

2014-09-01

97

Ethenzamide–gentisic acid–acetic acid (2/1/1  

Directory of Open Access Journals (Sweden)

Full Text Available In the title co-crystal solvate, 2-ethoxybenzamide–2,5-dihydroxybenzoic acid–ethanoic acid (2/1/1, 2C9H11NO2·C7H6O4·C2H4O2, two nonsteroidal anti-inflammatory drugs, ethenzamide (systematic name: 2-ethoxybenzamide and gentisic acid (systematic name: 2,5-dihydroxybenzoic acid, together with acetic acid (systematic name: ethanoic acid form a four-component molecular assembly held together by N—H...O and O—H...O hydrogen bonds. This assembly features two symmetry-independent molecules of ethenzamide, forming supramolecular acid–amide heterosynthons with gentisic acid and acetic acid. These heterosynthons involve quite strong O—H...O [O...O = 2.5446?(15 and 2.5327?(15?Å] and less strong N—H...O [N...O = 2.9550?(17 and 2.9542?(17?Å] hydrogen bonds. The overall crystal packing features several C—H...O and ?–? stacking interactions [centroid–centroid distance = 3.7792?(11?Å].

Srinivasulu Aitipamula

2010-05-01

98

Ethenzamide-gentisic acid-acetic acid (2/1/1).  

Science.gov (United States)

In the title co-crystal solvate, 2-ethoxy-benzamide-2,5-dihydroxy-benzoic acid-ethanoic acid (2/1/1), 2C(9)H(11)NO(2)·C(7)H(6)O(4)·C(2)H(4)O(2), two nonsteroidal anti-inflammatory drugs, ethenzamide (systematic name: 2-ethoxy-benzamide) and gentisic acid (systematic name: 2,5-dihydroxy-benzoic acid), together with acetic acid (systematic name: ethanoic acid) form a four-component mol-ecular assembly held together by N-H?O and O-H?O hydrogen bonds. This assembly features two symmetry-independent mol-ecules of ethenzamide, forming supra-molecular acid-amide heterosynthons with gentisic acid and acetic acid. These heterosynthons involve quite strong O-H?O [O?O = 2.5446?(15) and 2.5327?(15)?Å] and less strong N-H?O [N?O = 2.9550?(17) and 2.9542?(17)?Å] hydrogen bonds. The overall crystal packing features several C-H?O and ?-? stacking inter-actions [centroid-centroid distance = 3.7792?(11)?Å]. PMID:21579106

Aitipamula, Srinivasulu; Chow, Pui Shan; Tan, Reginald B H

2010-01-01

99

Enzymatic hydrolysis and fermentability of corn stover pretreated by lactic acid and/or acetic acid  

DEFF Research Database (Denmark)

Four different pretreatments with and without addition of low concentration organic acids were carried out on corn stover at 195 °C for 15 min. The highest xylan recovery of 81.08% was obtained after pretreatment without acid catalyst and the lowest of 58.78% after pretreatment with both acetic and lactic acid. Glucan recovery was less sensitive to the pretreatment conditions than xylan recovery. The pretreatment with acetic and lactic acid yielded the highest glucan recovery of 95.66%. The glucan recoveries of the other three pretreatments varied between 83.92% and 94.28%. Fermentability tests were performed on liquors obtained from all pretreatments and there were no inhibition effect found in any of the liquors. Simultaneous saccharification and fermentation (SSF) of water-insoluble solids (WIS) showed that a high ethanol yield of 88.7% of the theoretical based on glucose in the raw material was obtained following pretreatment at 195 °C for 15 min with acetic acid employed. The estimated total ethanol production was 241.1 kg/ton raw material by assuming fermentation of both C-6 and C-5, and 0.51 g ethanol/g sugar.

Xu, Jian; Thomsen, Mette Hedegaard

2009-01-01

100

Enantioselective protonation of ?-hetero carboxylic acid-derived ketene disilyl acetals under chiral ionic Brønsted acid catalysis.  

Science.gov (United States)

Highly enantioselective protonation of ?-halo and alkoxy carboxylic acid-derived ketene disilyl acetals is achieved by using P-spiro chiral diaminodioxaphosphonium barfate as a Brønsted acid catalyst, where the enantiofacial discrimination by the catalyst mainly stems from the recognition of the electronic difference between two substituents on the ketene disilyl acetal. PMID:25234847

Uraguchi, Daisuke; Kizu, Tomohito; Ohira, Yuki; Ooi, Takashi

2014-10-01

 
 
 
 
101

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

Energy Technology Data Exchange (ETDEWEB)

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.

Jerry D. Cohen

2009-11-01

102

The in vivo interaction between flavone acetic acid and hyperthermia  

DEFF Research Database (Denmark)

The in vivo interaction between flavone acetic acid (FAA) and hyperthermia was studied in a C3H mammary carcinoma grown in the feet of female CDF1 mice and in normal foot skin. FAA was intraperitoneally injected prior to local tissue heating in restrained non-anaesthetized animals. Alone, FAA at doses of 100 mg/kg and above, inhibited tumour growth in a dose-dependent fashion. FAA also enhanced the tumour response to heat, the effect being dependent on both the time interval between the two modalities and the FAA dose, the greatest effect occurring when FAA doses of > or = 150 mg/kg preceeded heat by 3-48 h. These effects of FAA correlated with the drug's ability to decrease tumour blood perfusion measured using the RbCl extraction procedure. Injecting 150 mg/kg FAA 3 h before heating (42.7 degrees C) resulted in a 2.2-fold increase in tumour heat damage, but had little effect on the response of normal foot skin in non-tumour-bearing mice. However, this treatment gave a 2.0-fold increase in normal tissue damage when the skin experiments were repeated in tumour-bearing animals. These effects in skin occurred in the absence of any blood perfusion changes, but appeared to be associated with FAA-induced TNF-alpha production.

Horsman, Michael Robert; Sampson, L E

1996-01-01

103

Water interactions with acetic Acid layers on ice and graphite.  

Science.gov (United States)

Adsorbed organic compounds modify the properties of environmental interfaces with potential implications for many Earth system processes. Here, we describe experimental studies of water interactions with acetic acid (AcOH) layers on ice and graphite surfaces at temperatures from 186 to 200 K. Hyperthermal D2O water molecules are efficiently trapped on all of the investigated surfaces, with only a minor fraction that scatters inelastically after an 80% loss of kinetic energy to surface modes. Trapped molecules desorb rapidly from both ?m-thick solid AcOH and AcOH monolayers on graphite, indicating that water has limited opportunities to form hydrogen bonds with these surfaces. In contrast, trapped water molecules bind efficiently to AcOH-covered ice and remain on the surface on the observational time scale of the experiments (60 ms). Thus, adsorbed AcOH is observed to have a significant impact on water-ice surface properties and to enhance the water accommodation coefficient compared to bare ice surfaces. The mechanism for increased water uptake and the implications for atmospheric cloud processes are discussed. PMID:24878257

Papagiannakopoulos, Panos; Kong, Xiangrui; Thomson, Erik S; Pettersson, Jan B C

2014-11-26

104

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2012-01-01

105

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

Science.gov (United States)

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. PMID:25093933

Liu, Xiangyong; Zhang, Xiaohua; Zhang, Zhaojie

2014-10-10

106

The synthesis of (14C-?) and (14C-?) 1,2-benzisoxazole-3-acetic acid  

International Nuclear Information System (INIS)

The preparation of 1,2-benzisoxazole-3-acetic acid labelled with 14C in position ? or ? of the side chain are described. ?-14C acid was obtained from 4-hydroxy coumarin [3-14C] via Fries rearrangement of phenyl acetate [methyl-14C]. ?-14C acid was synthesized from 4-hydroxy coumarin [2-14C] obtained from 14C-diethyl carbonate. Labelled positions were determined by mass spectrometry and were in agreement with the proposed reaction scheme. (author)

107

Theophylline-7-acetic acid derivatives with amino acids as anti-tuberculosis agents.  

Science.gov (United States)

A series of amides were synthesized by condensation of theophylline-7-acetic acid and eight commercially available amino acid methyl ester hydrochlorides. Consecutive hydrolysis of six of the amido-esters resulted in the formation of corresponding amido-acids. The newly synthesized compounds were evaluated for their in vitro activity against Mycobacterium tuberculosis H37Rv. The activity varied depending on the amino acid fragments and in seven cases exerted excellent values with MICs 0.46-0.26 ?M. Assessment of the cytotoxicity revealed that the compounds were not cytotoxic against the human embryonal kidney cell line HEK-293T. The theophylline-7-acetamides containing amino acid moieties appear to be promising lead compounds for the development of antimycobacterial agents. PMID:24878196

Voynikov, Yulian; Valcheva, Violeta; Momekov, Georgi; Peikov, Plamen; Stavrakov, Georgi

2014-07-15

108

Removal of lactobionic acid by electrodialysis  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Lactobionic acid has a number of applications, such as in cosmetic formulations and detergents, as well as in the medical field, where it is used for the preservation of organs destined for transplantation. Previous studies have reported that a promising alternative procedure for the production of l [...] actobionic acid is the biotechnological route, using permeabilized cells of Zymomonas mobilis to produce sorbitol and lactobionic acid from fructose and lactose. However, the acid produced during the process accumulates in the reaction medium, causing enzyme deactivation. It was found that this problem can be avoided by coupling an electrodialysis unit to the reaction vessel, resulting in efficient removal of the acid from the reaction medium and improved the stability of the enzyme. These tests employed a synthetic mixture containing lactobionic acid, sorbitol, lactose, and fructose, and a factorial design was performed to identify the most influential variables. The NaCl concentration in the concentrate stream, together with the potential difference, exerted the greatest effects on the rate of removal of lactobionic acid. In all experiments, the removal efficiency exceeded 95%. The best conditions for the system investigated were a potential of 60 V, and NaCl concentrations of 3 and 25 g L-1 in the concentrate stream and the electrode compartment, respectively.

J. B., Severo Júnior; T. L. M., Alves; H. C., Ferraz.

1003-10-01

109

Improving fermentation performance of recombinant Zymomonas in acetic acid-containing media.  

Science.gov (United States)

In the production of ethanol from lignocellulosic biomass, the hydrolysis of the acetylated pentosans in hemicellulose during pretreatment produces acetic acid in the prehydrolysate. The National Renewable Energy Laboratory (NREL) is currently investigating a simultaneous saccharification and cofermentation (SSCF) process that uses a proprietary metabolically engineered strain of Zymomonas mobilis that can coferment glucose and xylose. Acetic acid toxicity represents a major limitation to bioconversion, and cost-effective means of reducing the inhibitory effects of acetic acid represent an opportunity for significant increased productivity and reduced cost of producing fermentation fuel ethanol from biomass. In this study, the fermentation performance of recombinant Z. mobilis 39676:pZB4L, using a synthetic hardwood prehydrolysate containing 1% (w/v) yeast extract, 0.2% KH2PO4, 4% (w/v) xylose, and 0.8% (w/v) glucose, with varying amounts of acetic acid was examine. To minimize the concentration of the inhibitory undissociated form of acetic acid, the pH was controlled at 6.0. The final cell mass concentration decreased linearly with increasing level of acetic acid over the range 0-0.75% (w/v), with a 50% reduction at about 0.5% (w/v) acetic acid. The conversion efficiency was relatively unaffected, decreasing from 98 to 92%. In the absence of acetic acid, batch fermentations were complete at 24 h. In a batch fermentation with 0.75% (w/v) acetic acid, about two-thirds of the xylose was not metabolized after 48 h. In batch fermentations with 0.75% (w/v) acetic acid, increasing the initial glucose concentration did not have an enhancing effect on the rate of xylose fermentation. However, nearly complete xylose fermentation was achieved in 48h when the bioreactor was fed glucose. In the fed-batch system, the rate of glucose feeding (0.5 g/h) was designed to simulate the rate of cellulolytic digestion that had been observed in a modeled SSCF process with recombinant Zymomonas. In the absence of acetic acid, this rate of glucose feeding did not inhibit xylose utilization. It is concluded that the inhibitory effect of acetic acid on xylose utilization in the SSCF biomass-to-ethanol process will be partially ameliorated because of the simultaneous saccharification of the cellulose. PMID:9627380

Lawford, H G; Rousseau, J D

1998-01-01

110

Removal of 2.4-dichloro phenoxy-acetic acid from aqueous solution by adsorption on activated carbon. A kinetic study; Elimination de l'acide 2,4-dichloro phenoxyacetique d'une solution aqueuse par adsorption sur charbon actif. Etude cinetique  

Energy Technology Data Exchange (ETDEWEB)

The sorption of 2.4-dichloro phenoxy-acetic acid (2.4-D) on two different activated carbons was determined using the batch equilibration technique. The calculated slopes of the Freundlich sorption isotherms were significantly less than 1. The (K) values were higher for the activated carbon which has the higher specific surface, and increased with NaCl concentration. The rate of attaining equilibrium of 2.4-D increased with a decrease in adsorbent concentration. Dynamic modelling of the adsorption showed that a first order reversible kinetic model was followed for the adsorption process. The overall rate constant K', the adsorption rate K{sub 1}, the desorption rate constant K{sub 2}, and the equilibrium constant K{sub e} for the adsorption process were calculated. (authors)

Belmouden, M.; Assabbane, A.; Ait Ichou, Y. [Laboratoire de Chimie Physique, Equipe Photocatalyse et Environnement, Universite Ibnou Zohr, Faculte des Sciences, Agadir (Morocco)

2001-04-01

111

40 CFR 721.10074 - Acetic acid, 2-chloro-, 1-(3,3-dimethylcyclohexyl)ethyl ester.  

Science.gov (United States)

...2010-07-01 2010-07-01 false Acetic acid, 2-chloro-, 1-(3,3-dimethylcyclohexyl...Chemical Substances § 721.10074 Acetic acid, 2-chloro-, 1-(3,3-dimethylcyclohexyl...The chemical substance identified as acetic acid, 2-chloro-,...

2010-07-01

112

Acetic acid as a sclerosing agent for renal cysts: Comparison with ethanol in follow-up results  

International Nuclear Information System (INIS)

Purpose: To compare follow-up results of sclerotherapy for renal cyst using 50% acetic acid with those using 99% ethanol as sclerosing agents.Methods: Eighty-one patients underwent sclerotherapy and 58 patients, 23 males, 35 females, aged 6-76 years, having a total of 60 cysts, were included in this study; the others were lost to follow-up. The renal cysts were diagnosed by sonography, computed tomography (CT), or magnetic resonance imaging (MRI). Sclerotherapy was performed using 50% acetic acid for 32 cysts in 3 1 patients and 99% ethanol for 28 cysts in 27 patients. Under fluoroscopic guidance, cystic fluid was aspirated as completely as possible. After instillation of a sclerosing agent corresponding to 1 1.7%-25% (4-100 ml) of the aspirated volume, the patient changed position for 20 min and then the agent was removed. Patients were followed up by sonography for a period of 1-49 months. The volume of the renal cyst after sclerotherapy was compared with that of the renal cyst calculated before sclerotherapy. Medical records were reviewed to analyze complications.Results: The mean volume after sclerotherapy of the 17 cysts followed for 3-4 months in the acetic acid group was 5.1% of the initial volume, and for the 14 cysts in the ethanol group it was 10.2%. Complete regression during follow-up was shown in 21 cysts (66%) in the acetic acid group; the mean volume of these cysts before the procedure was 245 ml. The mean volume of the nine (32%) completely regressed cysts in the ethanol group was 184 ml. Mild flank pain, which occurred in three patients in each group, was the only complication and resolved the next day.Conclusion: Acetic acid was an effective and safe sclerosing agent for renal cysts, tending to induce faster and more complete regression than ethanol.

113

Acetic Acid as a Sclerosing Agent for Renal Cysts: Comparison with Ethanol in Follow-Up Results  

International Nuclear Information System (INIS)

Purpose: To compare follow-up results of sclerotherapy for renal cyst using 50% acetic acid with those using 99% ethanol as sclerosing agents.Methods: Eighty-one patients underwent sclerotherapy and 58 patients, 23 males, 35 females, aged 6-76 years, having a total of 60 cysts, were included in this study; the others were lost to follow-up. The renal cysts were diagnosed by sonography, computed tomography (CT), or magnetic resonance imaging (MRI). Sclerotherapy was performed using 50% acetic acid for 32 cysts in 31 patients and 99% ethanol for 28 cysts in 27 patients. Under fluoroscopic guidance, cystic fluid was aspirated as completely as possible. After instillation of a sclerosing agent corresponding to 11.7%-25% (4-100 ml) of the aspirated volume, the patient changed position for 20 min and then the agent was removed. Patients were followed up by sonography for a period of 1-49 months. The volume of the renal cyst after sclerotherapy was compared with that of the renal cyst calculated before sclerotherapy. Medical records were reviewed to analyze complications.Results: The mean volume after sclerotherapy of the 17 cysts followed for 3-4 months in the acetic acid group was 5.1% of the initial volume, and for the 14 cysts in the ethanol group it was 10.2%. Complete regression during follow-up was shown in 21 cysts (66%) in the acetic acid group; the mean volume of these cysts before the procedure was 245 ml. The mean volume of the nine (32%) completely regressed cysts in the ethanol group was 184 ml. Mild flank pain, which occurred in three patients in each group, was the only complication and resolved the next day.Conclusion: Acetic acid was an effective and safe sclerosing agent for renal cysts, tending to induce faster and more complete regression than ethanol

114

Smear layer removal with citric acid solution  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this study was to evaluate efficacy in smear layer removal of 17% EDTA and 10% citric acid, using SEM. Material and method: Twenty human, extracted teeth with a single root canal were examined. Whilst instrumentation with step-back technique and manual K files, root canals were irrigated with 2 ml of 2.5% NaOCl, between each file size. After instrumentatio n, specimens were divided into two groups. The first group was irrigated with a final flush of 17% EDTA, during one minute, and the second group was irrigated with a 10% citric acid. Results: Irrigation with 17% EDTA and 10% citric acid removed smear layer from the root canals walls. There was not statistically significant differences (p>0.05 in cleaning ability between EDTA and citric acid groups.

Petrovi? Violeta

2005-01-01

115

Chiral phosphoric acid directed regioselective acetalization of carbohydrate-derived 1,2-diols.  

Science.gov (United States)

In control: A chiral phosphoric acid catalyst significantly enhances or completely overrides the inherent regioselective acetalization profiles exhibited by monosaccharide-derived 1,2-diol substrates. This study represents the first example of chiral-catalyst-directed regio- and enantioselective intermolecular acetalizations, which are complementary to existing methods for substrate-controlled functionalization of polyols. PMID:24123751

Mensah, Enoch; Camasso, Nicole; Kaplan, Will; Nagorny, Pavel

2013-12-01

116

Effect of Exogenous Indole-3-acetic Acid and Naphthalene Acetic Acid on Regeneration of Damask Rose Cuttings in Three Growing Media  

Directory of Open Access Journals (Sweden)

Full Text Available An experiment was conducted to evaluate the performance of various levels of indole-3-acetic acid (IAA and naphthalene acetic acid (NAA treatments i.e., 0, 25, 50, 75, 100 mg L-1 on the regeneration of damask rose (Rosa damascena Mill. cuttings in different growing media at the research farm of Arid Zone Research Institute D.I. Khan during 2004. The data revealed significant effect of different levels of growth regulators and growing media on the rose establishment parameters viz., plant height, plant spread, number of primary shoots, secondary shoots and survival percentage. Maximum plant height (134.2 cm, plant spread (46.3 cm, primary shoots (6.3, secondary shoots (25 and survival percentage (94.72% were recorded when the rose cuttings were applied with NAA at the rate of 50 mg L-1. Among the plant growth regulators, Naphthalene Acetic Acid (NAA was found to be superior to indole-3-acetic acid (IAA for its stronger effect regarding all parameters. The optimum level of Naphthalene Acetic Acid (NAA was found in the range of 50 and 75 mg L-1, while no such conclusion could be drawn for indole-3-acetic acid (IAA as all growth parameters were linearly increased up to the highest concentrations of IAA i.e., 100 mg L-1. Regarding growing media, the leaf mould appeared the best in terms of its positive effect on establishment of rose cuttings by giving the maximum plant height (125.1 cm, plant spread (37 cm, primary shoots (5.2, secondary shoots (19.48 and survival percentage (85.67%, followed by soil + leaf mould, while soil media was least effective.

Rahmat Ullah Khan

2007-01-01

117

Effect of Tris-acetate buffer on endotoxin removal from human-like collagen used biomaterials.  

Science.gov (United States)

Protein preparation, which has active ingredients designated for the use of biomaterials and therapeutical protein, is obtained by genetic engineering, but products of genetic engineering are often contaminated by endotoxins. Because endotoxin is a ubiquitous and potent proinflammatory agent, endotoxin removal or depletion from protein is essential for researching any biomaterials. In this study, we have used Tris-acetate (TA) buffer of neutral pH value to evaluate endotoxins absorbed on the Pierce high-capacity endotoxin removal resin. The effects of TA buffer on pH, ionic strength, incubation time as well as human-like collagen (HLC) concentration on eliminating endotoxins are investigated. In the present experiments, we design an optimal method for TA buffer to remove endotoxin from recombinant collagen and use a chromogenic tachypleus amebocyte lysate (TAL) test kit to measure the endotoxin level of HLC. The present results show that, the endotoxins of HLC is dropped to 8.3EU/ml at 25 mM TA buffer (pH7.8) with 150 mM NaCl when setting incubation time at 6h, and HLC recovery is about 96%. Under this experimental condition, it is proved to exhibit high efficiencies of both endotoxin removal and collagen recovery. The structure of treated HLC was explored by Transmission Electron Microscopy (TEM), demonstrating that the property and structure of HLC treated by TA buffer are maintained. Compared to the most widely used endotoxin removal method, Triton X-114 extraction, using TA buffer can obtain the non-toxic HLC without extra treatment for removing the toxic substances in Triton X-114. In addition, the present study aims at establishing a foundation for further work in laboratory animal science and providing a foundation for medical grade biomaterials. PMID:25063101

Zhang, Huizhi; Fan, Daidi; Deng, Jianjun; Zhu, Chenghui; Hui, Junfeng; Ma, Xiaoxuan

2014-09-01

118

THE EFFECTS OF ANIMAL AGE AND ACETIC ACID CONCENTRATION ON PIGSKIN GELATIN CHARACTERISTICS  

Directory of Open Access Journals (Sweden)

Full Text Available This research was aimed to study the influence of animal age and concentration of the acetic acid solution on physical and chemical properties of pigskin gelatin. The experiment used Completely Randomized Design (CRD with two factors. The first factor was animal age consisted of 3 levels (5, 7 and 9 months. The second factor was concentration of acetic acid solution consisted of 3 levels (2, 4 and 6 percents. The result showed that animal age had significant effect (P0.05 on the yields, gel strength, viscosity, protein content and pH value. It was concluded that pigskin gelatin from ages of 5, 7 and 9 months and acetic acid concentration of 2, 4 and 6% had similar characteristics to the commercial gelatin, but the optimum production of gelatin was combination of pigskin gelatin from 7 months and of 2% acetic acid.

Y. Pranoto

2012-09-01

119

Production and Optimization of Indole Acetic Acid by Indigenous Micro Flora using Agro Waste as Substrate  

Directory of Open Access Journals (Sweden)

Full Text Available Indole Acetic Acid (IAA producing bacterium was isolated from the Rhizosphere soil and identified as Rhizobium sp. and Bacillus sp., Optimization of Indole acetic acid production was carried out at different cultural conditions, such as pH, temperature and substrate with Rhizobium sp., Bacillus sp. and Rhizobium sp., produced higher amount of Indole acetic acid (6.1 mg mL-1 than the Bacillus sp., (4.4 mg mL-1 at pH 7 and 37C in the Bengal gram substrate. Partial purification of Indole acetic acid was done by Thin Layer Chromatography (TLC. In conclusion Rhizobium sp., appear to be a suitable soil microorganism for high level of IAA production.

S. Yamuna Devi

2012-01-01

120

Bioproduction of usnic acid from acetate by kaolinite immobilized cells of Cladonia substellata Vain.  

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Full Text Available Cells of the lichen Cladonia substellata, immobilized in kaolinite and supplied with acetate, produce at room temperature large amounts of usnic acid which can be recovered from the washing solution.

Eugenia C. Pereira

1995-06-01

 
 
 
 
121

Complexing of zirconium and hafnium with halogen substituted of acetic acid in methanol solutions  

International Nuclear Information System (INIS)

The method of potentiometric titration was used to determine the reference stability constants for zirconium and hafnium complexes with fluoro-, chloro, iodo-, trifluoro-, and trichloro-acetic acid in methanol

122

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

Science.gov (United States)

...serotonin in urine. Measurements of 5-hydroxyindole acetic acid/serotonin are used in the diagnosis and treatment of carcinoid tumors of endocrine tissue. (b) Classification. Class I (general controls). The device is exempt from the...

2010-04-01

123

Complexation of chitosan with acetic acid according to Fourier transform Raman spectroscopy data  

Science.gov (United States)

The results of the interaction between the protonated chitosan (CHI) macromolecule and the acetate ion in dilute acetic acid solutions were studied by Fourier transform Raman spectroscopy and quantum-chemical modeling. The complexation of CHI with the acetate ion showed itself as the 934 cm-1 band in the Raman spectrum, which suggests the formation of [CHI+ · CH3COO-] type ion pairs. It was concluded that a comparative analysis of the integrated intensities of the Raman bands in the range 880-940 cm-1 makes it possible to judge about the relative content of hydrated acetate ions, CHI macromolecules of the [CHI+ · CH3COO-] complex, and acetic acid molecules not involved in CHI protonation.

Mikhailov, G. P.; Tuchkov, S. V.; Lazarev, V. V.; Kulish, E. I.

2014-06-01

124

Growing and laying performance of Japanese quail fed diet supplemented with different concentrations of acetic acid  

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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.

Mohammed A. Al-Harthi

2013-04-01

125

Triflic acid promoted direct ?-alkylation of unactivated ketones using benzylic alcohols via in situ formed acetals.  

Science.gov (United States)

Direct ?-alkylation of unactivated ketones using benzylic alcohols as electrophiles has been achieved at room temperature. This reaction takes place via in situ formed acetal using triflic acid and trimethyl orthoformate. It is believed that methyl vinyl ether formed from the in situ generated dimethyl acetal in the presence of triflic acid undergoes alkylation. Diverse ketones could be alkylated with diarylmethanols, cinnamyl alcohols, and phenyl propargyl alcohols having different electrophilicities. PMID:24901388

Koppolu, Srinivasa Rao; Naveen, Naganaboina; Balamurugan, Rengarajan

2014-07-01

126

The antimicrobial effect of acetic acid--an alternative to common local antiseptics?  

Science.gov (United States)

Acetic acid has been commonly used in medicine for more than 6000 years for the disinfection of wounds and especially as an antiseptic agent in the treatment and prophylaxis of the plague. The main goal of this study was to prove the suitability of acetic acid, in low concentration of 3%, as a local antiseptic agent, especially for use in salvage procedures in problematic infections caused by organisms such as Proteus vulgaris, Acinetobacter baumannii or Pseudomonas aeruginosa. This study was designed to compare the in vitro antimicrobial effect of acetic acid with those of common local antiseptics such as povidone-iodine 11% (Betaisodona), polyhexanide 0.04% (Lavasept), mafenide 5% and chlohexidine gluconate 1.5% cetrimide 15% (Hibicet). Former studies suggest the bactericidal effect of acetic acid, but these data are very heterogeneous; therefore, a standardised in vitro study was conducted. To cover the typical bacterial spectrum of a burn unit, the following Gram-negative and Gram-positive bacterial strains were tested: Escherichia coli, P. vulgaris, P. aeruginosa, A. baumannii, Enterococcus faecalis, Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus (MRSA) and beta-haemolytic Streptococcus group A and B. The tests showed excellent bactericidal effect of acetic acid, particularly with problematic Gram-negative bacteria such as P. vulgaris, P. aeruginosa and A. baumannii. The microbiological spectrum of acetic acid is wide, even when tested at a low concentration of 3%. In comparison to our currently used antiseptic solutions, it showed similar - in some bacteria, even better - bactericidal properties. An evaluation of the clinical value of topical application of acetic acid is currently underway. It can be concluded that acetic acid in a concentration of 3% has excellent bactericidal effect and, therefore, seems to be suitable as a local antiseptic agent, but further clinical studies are necessary. PMID:19286325

Ryssel, H; Kloeters, O; Germann, G; Schäfer, Th; Wiedemann, G; Oehlbauer, M

2009-08-01

127

Evolution of Acetic Acid Bacteria During Fermentation and Storage of Wine  

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Acetic acid bacteria were present at all stages of wine making, from the mature grape through vinification to conservation. A succession of Gluconobacter oxydans, Acetobacter pasteurianus, and Acetobacter aceti during the course of these stages was noted. Low levels of A. aceti remained in the wine; they exhibited rapid proliferation on short exposure of the wine to air and caused significant increases in the concentration of acetic acid. Higher temperature of wine storage and higher wine pH ...

Joyeux, A.; Lafon-lafourcade, S.; Ribe?reau-gayon, P.

1984-01-01

128

EFFECT OF INDOLE ACETIC ACID (IAA) ON FRUIT DROP AND FRUIT QUALITY OF DATE PALM CULTIVARS  

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Effect of Indole-3-Acetic Acid (IAA) on fruit drop and fruit quality of date palm cultivars was assessed during 2011 at Agriculture Research Institute, Rata Kulachi D.I.Khan, Pakistan. The experiment was laid out in Randomized Complete Block (RCB) Design with two factors factorial arrangement and replicated three times. The concentrations of Indole Acetic Acid (IAA) were used as 50, 100, 150 and 200 ppm at Hababuke stage (immature green stage) and the cultivars used were Dhakki and Gulistan. ...

Nasir Mahmood; Muhammad Junaid; Nazeer Ahmed; Asif Latif; Muhammad Sajid; Saeed Ahmed; Muhammad Umair

2013-01-01

129

Continuous Ethanol Production with a Membrane Bioreactor at High Acetic Acid Concentrations  

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Full Text Available The release of inhibitory concentrations of acetic acid from lignocellulosic raw materials during hydrolysis is one of the main concerns for 2nd generation ethanol production. The undissociated form of acetic acid can enter the cell by diffusion through the plasma membrane and trigger several toxic effects, such as uncoupling and lowered intracellular pH. The effect of acetic acid on the ethanol production was investigated in continuous cultivations by adding medium containing 2.5 to 20.0 g·L?1 acetic acid at pH 5.0, at a dilution rate of 0.5 h?1. The cultivations were performed at both high (~25 g·L?1 and very high (100–200 g·L?1 yeast concentration by retaining the yeast cells inside the reactor by a cross-flow membrane in a membrane bioreactor. The yeast was able to steadily produce ethanol from 25 g·L?1 sucrose, at volumetric rates of 5–6 g·L?1·h?1 at acetic acid concentrations up to 15.0 g·L?1. However, the yeast continued to produce ethanol also at a concentration of 20 g·L?1 acetic acid but at a declining rate. The study thereby demonstrates the great potential of the membrane bioreactor for improving the robustness of the ethanol production based on lignocellulosic raw materials.

Päivi Ylitervo

2014-07-01

130

On the exchange reaction between 14C labelled potassium thiocyanate and naphthalene acetic acid  

International Nuclear Information System (INIS)

The exchange reaction between 14C labelled potassium thiocyanate and naphthalene acetic acid has been studied to determine the possibility of isolating 14C labelled naphthalene acetonitrile. The labelled nitrile was subsequently hydrolysed to obtain the starting acid, in labelled form. The reaction conditions and the possibility of its application as a general reaction for synthesising carboxyl-14C labelled acids are discussed. (author)

131

Removal of Organic Acids from Effluent via Freeze Crystallization.  

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Full Text Available Freeze crystallization is an efficient separation process that can potentially be used in any application. Freeze crystallization is a high energy efficiency separation process that can be applied to a wide variety of industrial requirements. Although the vapor-liquid equilibrium is generally employed to separate the components of a solution, use of solid-liquid equilibrium should be considered – it may be cheaper. This paper describes a case study of recovery of acetic acid from effluent via freeze crystallization.Complete recovery of acetic acid from acetic acid-water solution by ordinary distillation is nearly impossible, because relative volatility of this mixture in the range of 1-30% of acetic acid in water is very close to one. Also, recovery of formic acid from its effluent stream by distillation is not economical viable as effluent stream of formic acid contains only 1-2% of formic acid. But the same separations are possible by freeze separation technique and it is found experimentally that large amount of acetic acid (about 70% and formic acid (about 90% can be recovered via freeze separation technique. Also it is found that the energy required for recovery of acetic acid is much lower (about 24 times than that of distillation.

Tarak C. Padhiyar

2013-05-01

132

High concentration preferential adsorption of zinc acetate onto acid treated activated carbon for impregnation purposes  

International Nuclear Information System (INIS)

Impregnation of activated carbon has long been the subject of researchers working in the area of protection against air pollutants, especially those interested in making personal protective equipments. People who are involved in research of heavy metal removal using activated carbon have worked at very low concentrations. Moreover, the literature available in the open domain does not reveal the secrets of working at high concentration i.e., greater than 1 mM. Working at higher salt concentrations is necessary for the purpose of impregnating the activated carbon to a certain level with metals like copper, zinc, silver, chromium, tungsten, molybdenum etc. Activated carbon impregnated with these metals can be very effective in the removal of certain toxic gases. A locally available microporous activated carbon GAC89 was pretreated with nitric acid. B.E.T. surface areas and Boehm titrations were done. A large range of concentrations of aqueous solution of zinc acetate which is a preferentially adsorbing salt was made and stirred with the raw AC and the pretreated AC. Atomic absorption spectroscopy was employed to determine the amount of zinc acetate actually adsorbed onto the carbon sample. The results were fitted to a sum of two distinct adsorption isotherms, one for low concentrations i.e., less than 1 mM, and the other for high concentrations. The lower concentration adsorption is largely influenced by the solution pH. It is observed that at higher concentrations, the served that at higher concentrations, the adsorption is weaker and the underlying mechanism is under study. (author)

133

Location and removal of deslorelin acetate implants in female African lions (Panthera leo).  

Science.gov (United States)

Contraception is necessary to manage zoo animal populations and to be able to house animals in groups without producing additional unwanted offspring. In felids and canids, an association between exposure to progestins and the occurrence of endometrial and mammary gland pathology has been documented. Therefore, the Association of Zoos and Aquariums (AZA) Wildlife Contraceptive Center recommends the use of deslorelin acetate for long-term contraception in carnivores. Return to cyclicity after deslorelin treatment has been variable; some individuals show ovarian suppression for long periods after the expected end of the deslorelin efficacy. In an attempt to reduce the time to reversal, techniques to locate and remove previous implants are being developed. This report documents the successful implementation of high-frequency ultrasonography in lions (Panthera leo) to locate and direct surgical removal of multiple deslorelin implants placed at least 2 yr previously as well as the return of follicular activity in both females at 7 months post-removal of implants. PMID:25000706

Moresco, Anneke; Dadone, Liza; Arble, Jason; Klaphake, Eric; Agnew, Dalen W

2014-06-01

134

Effects of the use of acetic acid as the conservant in lucerne ensiling  

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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.

?or?evi? Nenad

2004-01-01

135

Adsorptive removal of phenolic compounds using cellulose acetate phthalate–alumina nanoparticle mixed matrix membrane  

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Highlights: • Composite membrane of cellulose–acetate–phthalate and alumina nanoparticle is cast. • Surface charge of the membrane changes with nanoparticle concentration and pH. • Separation of phenolic compounds occurs due to adsorption. • The removal efficiency is maximum for 20% nanoparticle with 91% removal of catechol. • Transmembrane pressure drop has negligible effect on solute separation. -- Abstract: Mixed matrix membranes (MMMs) were prepared using alumina nanoparticles and cellulose acetate phthalate (CAP) by varying concentration of nanoparticles in the range of 10 to 25 wt%. The membranes were characterized by scanning electron micrograph, porosity, permeability, molecular weight cut off, contact angle, surface zeta potential, mechanical strength. Addition of nanoparticles increased the porosity, permeability of the membrane up to 20 wt% of alumina. pH at point of zero charge of the membrane was 5.4. Zeta potential of the membrane became more negative up to 20 wt% of nanoparticles. Adsorption of phenolic derivatives, catechol, paranitrophenol, phenol, orthochloro phenol, metanitrophenol, by MMMs were investigated. Variation of rejection and permeate flux profiles were studied for different solutes as a function of various operating conditions, namely, solution pH, solute concentration in feed and transmembrane pressure drop. Difference in rejection of phenolic derivatives is consequence of interplay of surface charge and adsorption by alumina. Adsorption isotherm was fitted for different solutes and effects of pH were investigated. Catechol showed the maximum rejection 91% at solution pH 9. Addition of electrolyte reduced the rejection of solutes. Transmembrane pressure drop has insignificant effects on solute rejection. Competitive adsorption reduced the rejection of individual solute.

Mukherjee, Raka; De, Sirshendu, E-mail: sde@che.iitkgp.ernet.in

2014-01-30

136

Adsorptive removal of phenolic compounds using cellulose acetate phthalate–alumina nanoparticle mixed matrix membrane  

International Nuclear Information System (INIS)

Highlights: • Composite membrane of cellulose–acetate–phthalate and alumina nanoparticle is cast. • Surface charge of the membrane changes with nanoparticle concentration and pH. • Separation of phenolic compounds occurs due to adsorption. • The removal efficiency is maximum for 20% nanoparticle with 91% removal of catechol. • Transmembrane pressure drop has negligible effect on solute separation. -- Abstract: Mixed matrix membranes (MMMs) were prepared using alumina nanoparticles and cellulose acetate phthalate (CAP) by varying concentration of nanoparticles in the range of 10 to 25 wt%. The membranes were characterized by scanning electron micrograph, porosity, permeability, molecular weight cut off, contact angle, surface zeta potential, mechanical strength. Addition of nanoparticles increased the porosity, permeability of the membrane up to 20 wt% of alumina. pH at point of zero charge of the membrane was 5.4. Zeta potential of the membrane became more negative up to 20 wt% of nanoparticles. Adsorption of phenolic derivatives, catechol, paranitrophenol, phenol, orthochloro phenol, metanitrophenol, by MMMs were investigated. Variation of rejection and permeate flux profiles were studied for different solutes as a function of various operating conditions, namely, solution pH, solute concentration in feed and transmembrane pressure drop. Difference in rejection of phenolic derivatives is consequence of interplay of surface charge and adsorption by alumina. Adsorption isotherm was fitted for different solutes and effects of pH were investigated. Catechol showed the maximum rejection 91% at solution pH 9. Addition of electrolyte reduced the rejection of solutes. Transmembrane pressure drop has insignificant effects on solute rejection. Competitive adsorption reduced the rejection of individual solute

137

Solvation model for the oxidation of methionine by imidazolium fluorochromate in aqueous acetic acid medium  

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Full Text Available The oxidation of methionine by imidazolium fluorochromate (IFC were studied, in the presence of chloroacetic acid, in water–acetic acid mixtures of varying molar compositions. The reaction is first order with respect to methionine, IFC and acid. The reaction rates were determined at different temperatures and the activation parameters were computed. The reaction rate increases with increasing mole fraction of acetic acid in the mixture and specific solvent–solvent–solute interactions were found to predominate (86 %. Asolvation model and a probable mechanism for the reaction are postulated.

BINCY JOHN

2006-01-01

138

Thermal decarboxylation of acetic acid: Implications for origin of natural gas  

Science.gov (United States)

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.

Kharaka, Y. K.; Carothers, W. W.; Rosenbauer, R. J.

1983-01-01

139

Microwave Spectroscopy and Proton Transfer Dynamics in the Formic Acid-Acetic Acid Dimer  

Science.gov (United States)

The rotational spectrum of the doubly hydrogen-bonded {hetero} dimer formed between formic acid and acetic acid has been recorded between 4 and 18 GHz using a pulsed-nozzle Fourier transform microwave spectrometer. Each rigid-molecule rotational transition is split into four as a result of two concurrent tunnelling motions, one being proton transfer between the two acid molecules, and the other the torsion/rotation of the methyl group within the acetic acid. We present a full assignment of the spectrum for {J} = 1 to {J} = 7 for these four torsion/tunnelling states. Spectra have been observed for the main isotopic species, with deuterium substitution at the C of the formic acid and all 13C species in natural abundance, The observed transitions are fitted to within a few kilohertz using a molecule-fixed effective rotational Hamiltonian for the separate {A} and {E} vibrational species of the G12 permutation-inversion group which is applicable to this complex. To reduce the effects of internal angular momentum, a non-principal axis system is used throughout. Interpretation of the internal motion uses an internal-vibration and overall rotation scheme, and full sets of rotational and centrifugal distortion constants are determined. The proton tunnelling rates and the internal angular momentum of the methyl group in the {E} states is interpreted in terms of a dynamical model which involves coupled proton transfer and internal rotation. The resulting potential energy surface not only describes these internal motions, but can also explain the observed shifts in rotational constants between {A} and {E} species, and the deviations of the tunnelling frequencies from the expected 2:1 ratio. It also permits the determination of spectral constants free from the contamination effects of the internal dynamics. M.C.D. Tayler, B. Ouyang and B.J. Howard, J. Chem. Phys., {134}, 054316 (2011).

Howard, B. J.; Steer, E.; Page, F.; Tayler, M.; Ouyang, B.; Leung, H. O.; Marshall, M. D.; Muenter, J. S.

2012-06-01

140

Removal of fluoride from aqueous nitric acid  

International Nuclear Information System (INIS)

Several methods for removing fluoride from aqueous nitric acid were investigated and compared with the frequently used aluminum nitrate-calcium nitrate (Ca2+-Al3+) chemical trap-distillation system. Zirconium oxynitrate solutions were found to be superior in preventing volatilization of fluoride during distillation of the nitric acid, producing decontamination factors (DFs) on the order of 2 x 103 (vs approx. 500 for the Ca2+-Al3+ system). Several other metal nitrate systems were tested, but they were less effective. Alumina and zirconia columns proved highly effective in removing HF from HF-HNO3 vapors distilled through the columns; fluoride DFs on the order of 106 and 104, respectively, were obtained. A silica gel column was very effective in adsorbing HF from HF-HNO3 solutions, producing a fluoride DF of approx. 104

 
 
 
 
141

Transport of acetic acid in Zygosaccharomyces bailii: effects of ethanol and their implications on the resistance of the yeast to acidic environments.  

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Cells of Zygosaccharomyces bailii ISA 1307 grown in a medium with acetic acid, ethanol, or glycerol as the sole carbon and energy source transported acetic acid by a saturable transport system. This system accepted propionic and formic acids but not lactic, sorbic, and benzoic acids. When the carbon source was glucose or fructose, the cells displayed activity of a mediated transport system specific for acetic acid, apparently not being able to recognize other monocarboxylic acids. In both typ...

Sousa, M. J.; Miranda, L.; Co?rte-real, M.; Lea?o, C.

1996-01-01

142

A case report of a chemical burn due to the misuse of glacial acetic acid.  

Science.gov (United States)

As young and elastic skin is what everyone dreams of, various measures have been implemented including chemical, laser resurfacing and dermabrasion to improve the condition of ageing skin. However, the high cost of these procedures prevents the poor from having access to treatment. Glacial acetic acid is widely used as a substitute for chemical peeling because it is readily easily available and affordable. However, its use can result in a number of serious complications. A 28-year-old female patient was admitted to our hospital with deep second-degree chemical burns on her face caused by the application of a mixture of glacial acetic acid and flour for chemical peeling. During a 6-month follow-up, hypertrophic scarring developed on the both nasolabial folds despite scar management. Glacial acetic acid is a concentrated form of the organic acid, which gives vinegar its sour taste and pungent smell, and it is also an important reagent during the production of organic compounds. Unfortunately, misleading information regarding the use of glacial acetic acid for chemical peeling is causing serious chemical burns. Furthermore, there is high possibility of a poor prognosis, which includes inflammation, hypertrophic scar formation and pigmentation associated with its misuse. Therefore, we report a case of facial chemical burning, due to the misuse of glacial acetic acid, and hope that this report leads to a better understanding regarding the use of this reagent. PMID:20708991

Yoo, Jun-Ho; Roh, Si-Gyun; Lee, Nae-Ho; Yang, Kyung-Moo; Moon, Ji-Hyun

2010-12-01

143

Enantioselective Additions of Boronates to Chromene Acetals Catalyzed by a Chiral Brønsted acid-Lewis acid System  

Science.gov (United States)

Chiral ?,?-dihydroxy carboxylic acids catalyze the enantioselective addition of alkenyl- and aryl boronates to chromene acetals. The optimal carboxylic acid is a tartaric acid amide, easily synthesized via a 3-step procedure. The reaction is enhanced by the addition of Lanthanide triflate salts such as cerium(IV)-and ytterbium(III) triflate. The chiral Brønsted acid and metal Lewis acid may be used in as low as 5 mol % relative to acetal substrate. Optimization of the reaction conditions can lead to yields >70% and enantiomeric ratios as high as 99:1. Spectroscopic and kinetic mechanistic studies demonstrate an exchange process leading to a reactive dioxoborolane intermediate leading to enantioselective addition to the pyrylium generated from the chromene acetal. PMID:20721997

Moquist, Philip N.; Kodama, Tomohiro; Schaus, Scott E.

2011-01-01

144

Large prebiotic molecules in space: photo-physics of acetic acid and its isomers  

CERN Document Server

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).

Puletti, Fabrizio; Mulas, Giacomo; Cecchi-Pestellini, Cesare

2009-01-01

145

Synthesis and evaluation of in vitro antiviral activity of novel phenoxy acetic acid derivatives.  

Science.gov (United States)

Several substituted phenoxy acetic acid derived pyrazolines were synthesized by the reaction between 2-{4-[3-(2,4-dihydroxyphenyl)-3-oxo-1-propenyl]-2-methoxyphenoxy} acetic acid and substituted acid hydrazides and were tested for their in vitro cytotoxicity and antiviral activity. None of the compounds showed any specific antiviral activity [50% antivirally effective concentration (EC(50)) > or = 5-fold lower than minimum cytotoxic concentration]. The most cytotoxic of the series was 2-{4-[3-(2,4-dihydroxyphenyl)-1-(2-hydroxybenzoyl-4,5-dihydro-1H-5-pyrazolyl]-2-methoxyphenoxy}acetic acid (3(j)), with a minimum cytotoxic concentration of 0.16 microg/mL in human embryonic lung (HEL) cells. PMID:18951282

Shahar Yar, M; Bakht, M Afroz; Siddiqui, A A; Abdullah, M M; De Clercq, Erik

2009-06-01

146

Effect of fluorophenylalanine on indole-3-acetic acid levels in Aveaa coleoptiles  

Directory of Open Access Journals (Sweden)

Full Text Available The effect of the amino acid analogue D,L-p-fluorophenylalanine on indole-3-acetic acid levels in Avena has been examined. Previous studies have established that D,L-p-fluorophenylalanine promotes elongation, lowers phenolic levels and depresses auxin oxidase activity of etiolated Avena coleoptiles. This study employs an enzyme immunoassay to measure endogenous indole-3-acetic acid concentrations in coleoptile apices. These data demonstrate that treatment of Avena coleoptiles with D,L-p-fluorophenylalanine results in altered auxin levels and help clarify the mechanism of D,L-p-fluorophenylalanine action in Avena

Andrew B. Maksymowych

1988-12-01

147

Glacial acetic acid as an efficient catalyst for simple synthesis of dindolylmethanes  

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Full Text Available Glacial acetic acid as a protic acid was employed as a catalyst in a solvent free condition for facile preparation of di(indolylmethanes (DIMs via one-pot condensation of indole with aryl or heteroaryl aldehydes. Various aryl and heteroaryl aldehydes were efficiently converted to the corresponding di(indolylmethanes (1a-p in high yields. The described novel synthetic method proposes several advantages of safety, mild condition, short reaction times, high yields, simplicity and the inexpensively glacial acetic acid compared to other catalysts.

Mardia El-Sayed

2014-01-01

148

Thermodynamic analysis of phenol acylation with acetic acid  

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Full Text Available Hydroxyacetophenones, especially the para-isomer, are important compounds in the pharmaceutical industry. They can be obtained through acylation of phenol but no data about the thermodynamic properties of this reaction are available. The estimation of the properties of this reaction, using the Benson method, shows that the formation of hydroxyacetophenones is favorable at temperatures between 300 K and 800 K. Higher temperatures favor the formation of phenyl acetate. In this temperature range, meta-hydroxyacetophenone is more stable than the other isomers.

Sobrinho E. Vitor

1998-01-01

149

Acetalization of hexanal with 2-ethyl hexanol catalyzed by solid acids  

Energy Technology Data Exchange (ETDEWEB)

The catalyst activity of solid acids such as niobium phosphate and Amberlyst 35, an ion exchange resin, was evaluated in the acetalization of hexanal with 2-ethyl-hexanol. The catalyst loading and the reaction temperature were evaluated in the hexanal conversions. The possibility of recycling niobium phosphate was also studied, showing that it was possible to reuse this catalyst without significant loss in its catalytic activity. The yield in acetal was above 90% under mild conditions. (author)

Barros, Alessandro O.; Faisca, Aline T.; Lachter, Elizabeth R.; Nascimento, Regina S.V.; San Gil, Rosane A.S., E-mail: lachter@iq.ufrj.b [Universidade Federal do Rio de Janeiro (IQ/UFRJ), RJ (Brazil). Inst. de Quimica

2011-07-01

150

Acetalization of hexanal with 2-ethyl hexanol catalyzed by solid acids  

International Nuclear Information System (INIS)

The catalyst activity of solid acids such as niobium phosphate and Amberlyst 35, an ion exchange resin, was evaluated in the acetalization of hexanal with 2-ethyl-hexanol. The catalyst loading and the reaction temperature were evaluated in the hexanal conversions. The possibility of recycling niobium phosphate was also studied, showing that it was possible to reuse this catalyst without significant loss in its catalytic activity. The yield in acetal was above 90% under mild conditions. (author)

151

A PreliminaryReport on the Mechanism of the Decomposition ofDiacetyl Peroxide in Acetic Acid  

Energy Technology Data Exchange (ETDEWEB)

The decomposition of diacetyl peroxide in acetic acid-2-C{sup 14} has been studied, The activity of the products in general confirmed the mechanism of the reaction as proposed by Kharasch and Gladstone, The presence and distribution of activity in the methyl acetate produced in this reaction is not explained by the previously proposed mechanism. There was no appreciable exchange of acetic acid and diacetyl peroxide under the conditions of the reaction. Essentially no exchange of methyl acetate and acetic acid was observed when those reagents mere heated at 100 for five hours.

Fry, A.J.; Tolbert, B.M.; Calvin, Melvin

1949-12-29

152

Acetic Acid Detection Threshold in Synthetic Wine Samples of a Portable Electronic Nose  

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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.

Miguel Macías Macías

2012-12-01

153

Impact of acetic acid concentration of fermented liquid feed on growth performance of piglets  

DEFF Research Database (Denmark)

Feeding fermented liquid feed (FLF) to pigs has proven to benefit gastrointestinal health of the animals. However, growth performance data of piglets and growing pigs fed FLF are variable and often a lower feed intake compared to feeding non-FLF or dry feed has been observed. Accumulation 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 feed intake on dry matter basis when feeding liquid feed to pigs. In conclusion, concentrations of acetic acid, at the levels normally measured in FLF, are not expected to affect markedly growth performance of piglets

Canibe, Nuria; Pedersen, Anni Øyan

2010-01-01

154

Phase equilibrium modelling for mixtures with acetic acid using an association equation of state  

DEFF Research Database (Denmark)

Acetic acid is a very important compound in the chemical industry with applications both as solvent and intermediate in the production of, e.g., polyesters. The design of these processes requires knowledge of the phase equilibria of mixtures containing acetic acid and a wide variety of compounds over extended temperature and pressure ranges. From the scientific point of view, modeling of such equilibria is challenging because of the complex association and solvation phenomena present. In this work, a previously developed association equation of state (cubic-plus-association, CPA) is applied to a wide variety of mixtures containing acetic acid, including gas solubilities, cross-associating systems (with water and alcohols), and polar chemicals like acetone and esters. Vapor-liquid and liquid-liquid equilibria are considered for both binary and ternary mixtures. With the exception of a somewhat inferior performance for the water-acetic acid VLE, which does not seem to affect substantially the performance for the multicomponent systems studied, CPA performs satisfactorily in most cases, using a single interaction parameter over extensive temperature ranges. For accurate description of water-acetic acid, use of the Huron-Vidal mixing rule for the energy parameter of CPA can yield a satisfactory correlation at the cost of more interaction parameters.

Muro Sunè, Nuria; Kontogeorgis, Georgios

2008-01-01

155

Olfactory receptor-based polypeptide sensor for acetic acid VOC detection.  

Science.gov (United States)

Rapid detection of food-borne pathogens in packaged food products can prevent the spread of infectious diseases. This study investigates the application of novel sensing material that is sensitive to specific indicator volatile organic compound (VOC) related to Salmonella contamination in packaged meat. Specifically, the objective was to develop an olfactory receptor-based synthetic polypeptide sensor for the detecting acetic acid in low concentrations and at room temperature. Synthetic polypeptide was deposited on a quartz crystal microbalance (QCM) electrode and was evaluated for detecting acetic acid at 10-100 ppm. Developed sensor exhibited repeatable response to a particular concentration of acetic acid and displayed reproducibility among multiple sensors during acetic acid detection. Mean estimated lower detection limits of these sensors were about 1-3 ppm and linear calibration models showed linear relationships. Thus, the QCM sensors exhibited a great potential for detecting low concentrations of acetic acid at room temperature and can be used in the sensor array for packaged meat spoilage and contamination detection. PMID:24364927

Panigrahi, Suranjan; Sankaran, Sindhuja; Mallik, Sanku; Gaddam, Bhushan; Hanson, Andrea A

2012-08-01

156

Corrosion and electrochemical behaviour of 316L stainless steel in acetic acid solutions  

Energy Technology Data Exchange (ETDEWEB)

The corrosion and electrochemical behaviour of 316S11 stainless steel in acetic acid solutions typifying chemical process environments has been investigated. Acetic acid concentrations tested were in the range 70-90% and included addition of 1500 ppm Br{sup -} and 200 ppm Na{sup +}. Of key interest was the impact of Cl{sup -} ions, representing an uncontrolled excursion in system chemistry. Corrosion potential-time and electrochemical polarisation measurements were made for the different environments at 90 deg. C and the characteristics of the surface film formed at different stages of exposure analysed using X-ray photo-electron spectroscopy (XPS). The most distinctive feature of the results was the step increase in potential with exposure time in the 70% acetic acid solution, in the absence of Cl{sup -} ions, indicating a sharp transition from active corrosion to some degree of passivity. No such transition was observed in the 90% acetic acid solution. Addition of chloride to the 70% acetic acid solution after the step in potential resulted in a step decrease in potential once a critical level of chloride had been exceeded. If the chloride were present on initial immersion, the potential stayed relatively low and the steel remained active. XPS analysis suggested that local enrichment of Mo was important in initiating the passivation process but the precise details of the mechanism remain speculative.

Turnbull, Alan; Ryan, Mary; Willetts, Anthony; Zhou Shengqi

2003-05-01

157

Acetic acid detection threshold in synthetic wine samples of a portable electronic nose.  

Science.gov (United States)

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. PMID:23262483

Macías, Miguel Macías; Manso, Antonio García; Orellana, Carlos Javier García; Velasco, Horacio Manuel González; Caballero, Ramón Gallardo; Chamizo, Juan Carlos Peguero

2013-01-01

158

Pitting Corrosion of Tin by Acetate Anion in Acidic Media  

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Full Text Available The corrosion behaviour of tin is studied in acetate buffer solutions (pH 4.5. The potentiodynamic anodic polarization curve in 0.1M acetate solution exhibits two anodic peaks A1 and A2 prior to the passive layer formation region which is followed by pitting corrosion. A1 and A2 are attributed to stannous and stannic species formation. The effect of scan rate on the potentiodynamic behaviour of tin in this solution was studied. It showed that the corrosion process in the potential range of peaks A1 and A2 is mass transport controlled. Pitting corrosion is confirmed by light microscope images. The negative going scans of the cyclic voltammograms show three cathodic peaks C1, C2 and C3. The potentiostatic current time transients, at different electrolyte concentrations and applied potentials (around the pitting potential involve three stages. The first stage, in which current decreases rapidly with time till reaching a minimum value im at the incubation time ti . The second and third stages, where current increases again linearly with time at two different slopes, are correlated to the pit nucleation and growth respectively. The nucleation rate (ti-1 was found to increase with increasing the electrolyte concentration and the anodic applied potential. The impedance spectra, at potentials of passive layer and pitting formations, exhibit a high frequency conductive semicircle and a low frequency inductive loop. The results showed a decrease in the electrode impedance as the applied potential approached the pitting potential.

Hamdy H. Hassan, Khalid Fahmy

2008-01-01

159

Preparation and characterization of modified cellulose acetate membrane to remove europium (III) and cesium from their wastes  

International Nuclear Information System (INIS)

In this work, modified cellulose acetate based membranes were prepared by blending cellulose acetate (CA) with polyethyleneglycol (PEG) and acrylamide (AAm) in various concentrations. Characterizations of the prepared membranes such as swelling behavior and IR were investigated. Batch technique were used to investigate the removal of Eu(III) and Cs from their wastes. Effect of pH, contact time, concentrations, temperature and adsorbent dosage on the removal process was determined in absence and presence of polymeric additives. The results showed good adsorption capacities of Eu(III) and Cs on modified cellulose acetate membrane compared to pure cellulose acetate. The adsorption capacity of Eu(III) and Cs increases as a function of concentration of PEG and AAm. The percent removal of Eu(III) on CA, CA/AAm and CA/PEG was 64, 82 and 98 respectively, while the percentage removal of Cs on CA, CA/AAm and CA/PEG was 53, 78 and 89 respectively. Batch desorption and regeneration experiments revealed that 0.5 M HCl performed well in eluting Eu(III) and Cs and caused very low damage to the prepared membranes. Reuse of the prepared membrane after one sorption cycle resulted in less than about 13% (for Eu), 12% (for Cs) reduction in the sorption capacity of the isotopes suggesting that the prepared membrane is a multiple-use adsorbent. The adsorption isotherm behavior of the prepared membranes fit Langmuir isotherm. (author)

160

Preparation and Characterization of Modified Cellulose Acetate Membrane to Remove Europium(III) and Cesium from Their Wastes  

International Nuclear Information System (INIS)

In this work, modified cellulose acetate based membranes were prepared by blending cellulose acetate (CA) with polyethylene glycol (PEG) and acrylamide (AAm) in different concentrations. Characterization of the prepared membranes such as swelling behavior and IR were investigated. Batch technique was used to investigate the removal of Eu(III) and Cs from their wastes. Effect of ph, contact time, monomer concentrations, temperature and adsorbed dose on the removal process was determined in the absence and presence of polymeric additives. The results showed good adsorption capacities of Eu(III) and Cs on the prepared modified cellulose acetate membrane compared to pure cellulose acetate. The adsorption capacity of Eu(llI) and Cs increases as a function of concentration of PEG and AAm. The percent removal of Eu(III) on CA, CNAAm and CAIPEG was 64, 82 and 98 %, respectively, while the percent removal of Cs on CA, CA/AAm and CA/PEG was 53, 78 and 89 %, respectively. Batch desorption and regeneration experiments revealed that 0.5 M HCl performed well in eluting Eu(III) and Cs and caused very low damage to the prepared membranes. Reuse of the prepared membrane after one sorption cycle resulted reduction in the sorption capacity in less than about 13% for Eu and 12% for Cs. This is suggesting that the prepared membrane is a multiple-use adsorbent. The adsorption isotherm behavior of the prepared membranes fit Langmuir isotherm.

 
 
 
 
161

ANTIBACTERIAL AND ANTIFUNGAL ACTIVITIES OF THE OXIDISED PRODUCT OF INDOLE-3- ACETIC ACID BY POTASSIUM BROMATE SCAVENGED AND UNSCAVENGED BY MERCURIC ACETATE  

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Full Text Available The oxidation of indole-3-acetic acid by potassium bromate in acetic acid medium was studied.  The oxidation of IAA was done in the presence and absence of the scavenger mercuric acetate. The final product was identified as 3-methylene oxindole by the IR and NMR spectral studies and then examined for biological activity. The antibacterial activity was carried out by agar diffusion method. The antifungal activity of the synthesised product was evaluated by agar diffusion method using potato dextrose agar.

Deepa D*, Chandramohan G, Chandralekha S and Sumathi P

2013-01-01

162

Acetic acid as an intervention strategy to decontaminate beef carcasses in mexican commercial slaughterhouse  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Beef can be contaminated during the slaughter process, thus other methods, besides the traditional water washing, must be adopted to preserve meat safety. The objective of this study was to evaluate the effect of 2% acetic acid interventions on the reduction of indicator bacteria on beef carcasses a [...] t a commercial slaughterhouse in Mexico. Reduction was measured by the count of mesophilic aerobic bacteria (TPC), total coliform (TC), and fecal coliform (FC) (log CFU/ cm²). Among the different interventions tested, treatments combining acetic acid solution sprayed following carcass water washing had greater microbial reduction level. Acetic acid solution sprayed at low pressure and longer time (10-30 psi/ 60 s) reached higher TPC, TC, and FC reductions than that obtained under high pressure/ shorter time (1,700 psi/ 15 s; P

Laura, Reyes Carranza; Maria Salud, Rubio Lozano; Ruben Danilo, Méndez Medina; Maria Del Carmen Wacher, Rodarte; Jose Fernando, Núñez Espinosa; Bertha Lucila, Velázquez Camacho; Renata Ernlund Freitas, Macedo.

163

Nickel adsorption onto carbon anode dust modified by acetic acid and KOH  

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Full Text Available Carbon anode dust (CAD is metallurgical waste material of aluminium production industry. The objective of this study was to convert carbon anode dust to acetic acid-modified and KOH-modified carbon adsorbat. Modified and unmodified carbon anode dust samples were characterized by SEM analysis. Pore volume, pore size and surface area were determined with BET method. The prepared carbons were evaluated for their adsorption capacity of nickel ions. The experimental data were analyzed by Freundlich and Langmuir isotherms. Changes in the surface morphology, surface area properties and obtained adsorption capacity indicate that acetic acid is a better modifier than KOH. Equilibrium results showed that acetic acid modification increased the CAD adsorption capacity for Ni (II more than KOH modification.

Štrkalj A.

2010-01-01

164

1,2-Di-4-pyridylethane N,N?-dioxide–acetic acid (1/2  

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Full Text Available The title compound, C12H12N2O2·2C2H4O2, was prepared from 1,2-di-4-pyridylethane, acetic acid, and hydrogen peroxide. The 1,2-di-4-pyridylethane N,N?-dioxide molecule is located on an inversion center. ?–? stacking interactions between neighboring 1,2-di-4-pyridylethane N,N?-dioxide molecules are observed with a centroid–centroid distance of 3.613?Å, an interplanar distance of 3.317?Å, and a slippage of 1.433?Å. O—H...O hydrogen-bonding interactions between 1,2-di-4-pyridylethane N,N?-dioxide and acetic acid molecules result in distinct hydrogen-bonded units made of one N-oxide and two acetic acid molecules. These units are then linked into a three-dimensional network through weaker C—H...O hydrogen-bonding interactions.

Jacqueline M. Knaust

2009-12-01

165

Molecular mechanisms of Saccharomyces cerevisiae stress adaptation and programmed cell death in response to acetic acid  

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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.

SergioGiannattasio

2013-02-01

166

Acetic acid as an intervention strategy to decontaminate beef carcasses in mexican commercial slaughterhouse  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Beef can be contaminated during the slaughter process, thus other methods, besides the traditional water washing, must be adopted to preserve meat safety. The objective of this study was to evaluate the effect of 2% acetic acid interventions on the reduction of indicator bacteria on beef carcasses a [...] t a commercial slaughterhouse in Mexico. Reduction was measured by the count of mesophilic aerobic bacteria (TPC), total coliform (TC), and fecal coliform (FC) (log CFU/ cm²). Among the different interventions tested, treatments combining acetic acid solution sprayed following carcass water washing had greater microbial reduction level. Acetic acid solution sprayed at low pressure and longer time (10-30 psi/ 60 s) reached higher TPC, TC, and FC reductions than that obtained under high pressure/ shorter time (1,700 psi/ 15 s; P

Laura, Reyes Carranza; Maria Salud, Rubio Lozano; Ruben Danilo, Méndez Medina; Maria Del Carmen Wacher, Rodarte; Jose Fernando, Núñez Espinosa; Bertha Lucila, Velázquez Camacho; Renata Ernlund Freitas, Macedo.

2013-09-01

167

Acetic acid induced ulceration in rats is not affected by infection with Hymenolepis diminuta.  

Science.gov (United States)

Analysis of rodent models of inflammatory bowel disease, airways hyper-reactivity, diabetes, and multiple sclerosis has shown that infection with helminth parasites can significantly reduce the severity of the disease. Here, we assessed whether rats infected with the tapeworm Hymenolepis diminuta were protected from gastric ulceration induced by the serosal application of acetic acid. All rats gavaged with infective cysticercoids harbored adult worms when assessed 6 wk later, and acetic acid evoked the expected gastric ulceration. However, infection with H. diminuta did not affect the degree of gastric ulceration at either 3 or 7 days post-acetic acid application, as gauged by ulcer area or histopathology. While the data do not dismiss the possibility that infection with other helminths could be anti-ulcerogenic, they illustrate that 'helminth therapy' for inflammatory disease is likely to be both disease- and helminth-specific. PMID:18767911

McKay, Derek M; Wallace, John L

2009-04-01

168

The Effect of Curcumin (Active Substance of Turmeric)on the Acetic Acid-Induced Visceral Nociception in Rats  

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In the present study, the effect of chronic oral administration of curcumin in the presence or absence of morphine and noloxone was investigated on the visceral nociception induced by acetic acid in rats. Intraperitoneal injection of acetic acid (1 mL, 2%) produced contractions in the abdominal musculature (writhes). The latency time to the beginning of the first writhe was measured and the total number of writhes in the 1 h after acetic acid injection was counted. The latency time to the ...

Hossein Tajik; Esmaeal Tamaddonfard; Nasrin Hamzeh-Gooshchi

2008-01-01

169

Preventive activity of ascorbic acid on lead acetate induced cerebellar damaged in adult Wistar rats  

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Full Text Available Among the environmental contaminants, lead is one of the most hazardous to living matter. In mammals, the main target is the central nervous system, particularly in the young. Ascorbic acid is an antioxidant which is a substance that may protect your cells against the effects of free radicals. This study investigated Experiment the protective effect of ascorbic acid on the cerebellum of adult Wistar rats following oral administration of different doses of Lead acetate. Thirty adult Wistar rats of average weight of 215g were used in this study. The animals were divided into five (5 groups of six animals per group and were administered different doses of lead acetate (60mg/kg bwt of 1/10th LD50 and 30mg/kg bwt of 1/20th of LD50 and ascorbic acid (4.3mg/kg bwt orally over a period of three (3 weeks.Group 1 (control was administered distilled water and Group 2 and 3 were administered 30mg/kg and 60mg/kg of Lead acetate respectively while Group 4 and 5 were given co-administration of 30mg/kg of Lead acetate 4.3mg/kg of ascorbic acid and 60gm/kg of Lead acetate 4.3mg/kg of ascorbic acid respectively. Histopathologically, Lead acetate induced cellular damage in the cerebellum of adult Wistar rats and it was also observed that ascorbic acid prevents or minimize lead-induced cellular damage in the cerebellum of adult Wistar rats.

Sunday Abraham Musa

2012-12-01

170

Effect of acetic acid on optical coherence tomography (OCT) images of cervical epithelium.  

Science.gov (United States)

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 facilitate the distinction between dysplastic lesions in a clinical setting needs to be shown in further studies. PMID:24828107

Gallwas, Julia; Stanchi, Anna; Dannecker, Christian; Ditsch, Nina; Mueller, Susanna; Mortensen, Uwe; Stepp, Herbert

2014-11-01

171

EFFECT OF INDOLE ACETIC ACID (IAA ON FRUIT DROP AND FRUIT QUALITY OF DATE PALM CULTIVARS  

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Full Text Available Effect of Indole-3-Acetic Acid (IAA on fruit drop and fruit quality of date palm cultivars was assessed during 2011 at Agriculture Research Institute, Rata Kulachi D.I.Khan, Pakistan. The experiment was laid out in Randomized Complete Block (RCB Design with two factors factorial arrangement and replicated three times. The concentrations of Indole Acetic Acid (IAA were used as 50, 100, 150 and 200 ppm at Hababuke stage (immature green stage and the cultivars used were Dhakki and Gulistan. The application of IAA significantly influenced the growth, yield components and reduced the fruit drop of date palm cultivars. Among cultivars, Dhakki cultivar showed more fruit length (4.97 cm, fruit diameter (3.03 cm, fruit weight (30.8 g and pulp weight (29.16 g when treated with 150 ppm Indole Acetic Acid, while the lower percent fruit drop (23.00% and higher bunch weight (21.27 kg was recorded in cultivar Gulistan with application of 150 ppm Indole Acetic Acid concentration. Cultivars effect was also significant for percent fruit drop, fruit length, fruit diameter, fruit weight, pulp weight and bunch weight. In case of interactions only length and pulp weight was found significant among all other parameter in both cultivars. Results revealed that application of Indole Acetic Acid as foliar spray @ 150 ppm showed good result to minimize the percent fruit drop of date palm cultivars and also affects other desirable parameters significantly. Therefore, the concentration of Indole Acetic Acid (IAA @ 150 ppm should be applied as foliar spray at kimri stage (unripe stage to minimize the fruit drop and to improve the fruit quality attributes of date palm cultivars.

Nasir Mahmood

2013-03-01

172

THIOGLYCOLIC ACID ESTERIFIED IN TO RICE STRAW FOR REMOVING LEAD FROM AQUEOUS SOLUTION  

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Full Text Available Thiol rice straw (TRS was prepared by esterifying thioglycolic acid onto rice straw in the medium of acetic anhydride and acetic acid with sulfuric acid as catalyst. The sorption of lead (Pb on TRS from aqueous solution was subsequently investigated. The batch experiments showed that Pb removal was dependent on initial pH, sorbent dose, Pb concentration, contact time, and temperature. The maximum value of Pb removal appeared at pH 5. For 100 mg/L of Pb solution, a removal ratio of greater than 98% could be achieved with 2.0 g/L or more of TRS. The isothermal data of Pb sorption conformed well to the Langmuir model, and the maximum sorption capacity (Qm of TRS for Pb was 104.17 mg/g. The equilibrium of Pb removal was reached within 120 min. The Pb removal process could be described by the pseudo-first-order kinetic model. The thermodynamic study indicated that the Pb removal process was spontaneous and endothermic.

R. Gong

2011-09-01

173

Radiation-thermal decomposition of nitric and acetic acids in the aqueous nitrate solution  

International Nuclear Information System (INIS)

Kinetics of radiation, thermal and radiation-thermal decompositions of nitric and acetic acid mixture was investigated in aqueous sodium nitrate solution in homogeneous conditions as well as by interaction of solid phase as sand rock. Temperature dependences of rate of radiation, thermal and radiation-thermal decompositions of the acids were calculated using experimental data. Resulting solutions make possible the calculation of acid decomposition dynamics accounting conditions of underground radioactive waste disposals

174

Low acetate concentrations favor polyphosphate-accumulating organisms over glycogen-accumulating organisms in enhanced biological phosphorus removal from wastewater.  

Science.gov (United States)

Glycogen-accumulating organisms (GAOs) are thought to compete with polyphosphate-accumulating organisms (PAOs) in enhanced biological phosphorus removal (EBPR) wastewater treatment systems. A laboratory sequencing batch reactor (SBR) was operated for one year to test the hypothesis that PAOs have a competitive advantage at low acetate concentrations, with a focus on low pH conditions previously shown to favor GAOs. PAOs dominated the system under conventional SBR operation with rapid acetate addition (producing high in-reactor concentrations) and pH values of 7.4-8.4. GAOs dominated when the pH was decreased (6.4-7.0). Decreasing the acetate addition rate led to very low reactor acetate concentrations, and PAOs recovered, supporting the study hypothesis. When the acetate feed rate was increased, EBPR failed again. Dominant PAOs and GAOs were Candidatus Accumulibacter phosphatis and Defluviicoccus Cluster 2, respectively, according to fluorescent in situ hybridization and 454 pyrosequencing. Surprisingly, GAOs were not the immediate causes of PAO failures, based on functional and population measurements. Pyrosequencing results suggested Dechloromonas and Tetrasphaera spp. may have also been PAOs, and additional potential GAOs were also identified. Full-scale systems typically have lower in-reactor acetate concentrations than laboratory SBRs, and so, previous laboratory studies may have overestimated the practical importance of GAOs as causes of EBPR failure. PMID:23477409

Tu, Yunjie; Schuler, Andrew J

2013-04-16

175

Inhibition of microbial xylitol production by acetic acid and its relation with fermentative parameters.  

Science.gov (United States)

Precipitated sugarcane bagasse hemicellulosic hydrolysate containing acetic acid was fermented by Candida guilliermondii FTI20037 under different operational conditions (pH 4.0 and 7.0, three aeration rates). At pH 7.0 and kLa of 10 (0.75 vvm) and 22.5/h (3.0 vvm) the acetic acid had not been consumed until the end of the fermentations, whereas at the same pH and kLa of 35/h (4.5 vvm) the acid was rapidly consumed and acetic acid inhibition was not important. On the other hand, fermentations at an initial pH of 4.0 and kLa of 22.5 and 35/h required less time for the acid uptake than fermentations at kLa of 10/h. The acetic acid assimilation by the yeast indicates the ability of this strain to ferment in partially detoxified medium, making possible the utilization of the sugarcane bagasse hydrolysate in this bio-process. The effects on xylitol yield and production are reported. PMID:10849838

Morita, T A; Silva, S S

2000-01-01

176

Synthesis and biological activity of thiazolyl-acetic acid derivatives as possible antimicrobial agents.  

Science.gov (United States)

5a-h, a series of (5-substituted-2-methyl-1,3-thiazole-4-yl) acetic acids as heterocyclic acetic acid derivatives, was designed and synthesized from ethyl acetoacetate. The synthesized compounds were screened for their antimicrobial activities against bacterial and fungal strains, and their characteristics were investigated by assays under various temperature and pH conditions. Cytotoxicity was evaluated with the use of sheep erythrocytes and human neonate dermal fibroblasts. Similarly, agents such as lauric acid 6 and parabens 7a-b, which are used as preservative agents for commercial cosmetics and detergents, were assayed for comparison. Although the structure of 5a is simple, comprising a thiazole attached with an octyl group and acetic acid moiety, the compound showed stronger and broader antibacterial and antifungal activities among the 5 series against the tested microbes other than gram-negative bacteria. Interestingly, 5a overcame the weak antifungal activity of parabens 7a-b. Also, the cytotoxicity of 5a was less than that of parabens 7a-b, especially to human dermal fibroblasts. These results suggest that thiazolyl-acetic acid 5a is a potentially effective biocide, and that it could be used as a preservative agent in commercially sold cosmetics and detergents, facilitated by the hydrophilic and charge properties of its carboxylic acid moiety. PMID:23796637

Shirai, Akihiro; Fumoto, Yasuko; Shouno, Tomoaki; Maseda, Hideaki; Omasa, Takeshi

2013-01-01

177

Cyclodextrin-grafted electrospun cellulose acetate nanofibers via “Click” reaction for removal of phenanthrene  

Science.gov (United States)

Beta-cyclodextrin (?-CD) functionalized cellulose acetate (CA) nanofibers have been successfully prepared by combining electrospinning and “click” reaction. Initially, ?-CD and electrospun CA nanofibers were modified so as to be azide-?-CD and propargyl-terminated CA nanofibers, respectively. Then, “click” reaction was performed between modified CD molecules and CA nanofibers to obtain permanent grafting of CDs onto nanofibers surface. It was observed from the SEM image that, while CA nanofibers have smooth surface, there were some irregularities and roughness at nanofibers morphology after the modification. Yet, the fibrous structure was still protected. ATR-FTIR and XPS revealed that, CD molecules were successfully grafted onto surface of CA nanofibers. The adsorption capacity of ?-CD-functionalized CA (CA-CD) nanofibers was also determined by removing phenanthrene (polycyclic aromatic hydrocarbons, PAH) from its aqueous solution. Our results indicate that CA-CD nanofibers have potential to be used as molecular filters for the purpose of water purification and waste water treatment by integrating the high surface area of nanofibers with inclusion complexation property of CD molecules.

Celebioglu, Asli; Demirci, Serkan; Uyar, Tamer

2014-06-01

178

Performance of Granular Activated Carbon to 2,4-Dichlorophenoxy Acetic Acid Aemoval from Aqueous Environments  

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Full Text Available Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 Background and Objectives: 2, 4-dichlorophenoxy acetic acid is a well-known herbicide which can be dangerous for  both human and animal health in different ways such as its presence in drinking water. This study aimed at Performance of granular activated carbon to 2-4-D removal from aqueous solution and assessing the relationship between COD and 2-4-D concentration Materials and Methods: This study is a lab-scale study. Firstly, different 2-4-D concentrations were prepared from Stock solution (1000 mg/L, and then their CODs were measured. Optimum pH for 2-4-D removal was determined and its absorption rate at different concentrations was measured. Results: Results showed a clear relationship between COD and 2-4-D concentration. On the other hand, COD removal increased as time elapsed, so that maximum removal 90% and 84% at initial 2-4-D concentrations of 50 and 100 mg/L were observed at contact time of 50 min respectively. Optimum pH for all concentrations was determined as 6. Conclusion: According to present study it can be concluded that activated carbon have be up to 90% of 2-4-D removal from water environment. In addition, a significant relationship was observed between COD and 2-4-D concentration, so that direct measurement of COD can be used instead of 2-4-D measurement. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;}

Meghdad Pirsaheb

2012-04-01

179

Extractive Distillation of Acetic Acid from its Dilute Solution using Lithium Bromide  

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Full Text Available Separation and purification are an integral part and a major cost factor in the chemical industry. Distillation is a very commonly used for solvent separation and purification process. It is neither cost effective nor process efficient when dealing with close-boiling and azeotropic solvent mixtures without modifying the relative volatility of the solvent components with an extraneous solvent or a non-volatile solute electrolyte or nonelectrolyte. The selection of a suitable modifier generally depends on the experimental determination of its effect on the Vapour–Liquid Equilibrium (VLE of the solvent mixture. Acetic acid is most widely used as aliphatic carbonic acid. It is frequently used as a solvent like in manufacture of cellulose acetate or in manufacture of many pharmaceutical products. Aqueous acetic acid is obtained during these processes and recovery of which is of great significance. Separation of pure water from dilute solution of Acetic acid –water mixture in the concentration range of 1 % to 30 % Acetic acid by simple rectification is almost impossible as relative volatility of the mixture in this range approaches unity.We would then require towers with large number of stages which would be operated with high reflux ratio and required high energy costs and operating costs. In practice extraction with suitable solvent is carried out before pure recovery occurs during the rectification of azeotropic mixture. An alternative separation process is the addition of Lithium Bromide(LiBr salt into acetic-acid water solution . Lithium bromide is largely soluble in water. Addition of salt will increase the boiling point of salt-water solution, there by separating comparatively pure acetic acid as overhead product. LiBr–water solution remains as residue from which LiBr can be readily separated by evaporation and reused. Experiments are carried out in laboratory with different concentrations of Acetic acid-water, in Othmer still which is vapor-liquid equilibrium apparatus. An Extractive distillation column will be designed based on experimental results. Cost analysis of this new separation technique will be carried out. The experimental data will be correlated to any model to calculate activity coefficients

R.P.Bhatt

2012-04-01

180

THE EFFECTS OF ANIMAL AGE AND ACETIC ACID CONCENTRATION ON PIGSKIN GELATIN CHARACTERISTICS  

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This research was aimed to study the influence of animal age and concentration of the acetic acid solution on physical and chemical properties of pigskin gelatin. The experiment used Completely Randomized Design (CRD) with two factors. The first factor was animal age consisted of 3 levels (5, 7 and 9 months). The second factor was concentration of acetic acid solution consisted of 3 levels (2, 4 and 6 percents). The result showed that animal age had significant effect (P<0.01) on the yields...

Pranoto, Y.; Pertiwiningrum, A.; Triatmojo, S.; Sompie, M.

2012-01-01

 
 
 
 
181

Adiabatic ionization potential of acetic acid and torsional dynamics of its cation.  

Science.gov (United States)

Pulsed-field-ionization zero-kinetic-energy photoelectron spectroscopy and supersonic cooling are used to investigate the CH(3) torsional dynamics of the acetic acid cation and to determine an accurate value for the first adiabatic ionization potential of acetic acid (IP=85 912+/-5 cm(-1)), which has been the subject of debates for more than 40 yr. A doubling of the torsional barrier upon ionization is due to a significant shortening of the C-C bond and reduces the tunneling efficiency by an order of magnitude. PMID:19508049

Zielke, Philipp; Forysinski, Piotr W; Luckhaus, David; Signorell, Ruth

2009-06-01

182

Mechanisms leading to oligomers and SOA through aqueous photooxidation: insights from OH radical oxidation of acetic acid and methylglyoxal  

Science.gov (United States)

Previous experiments have demonstrated that the aqueous OH radical oxidation of methylglyoxal produces low volatility products including pyruvate, oxalate and oligomers. These products are found predominantly in the particle phase in the atmosphere, suggesting that methylglyoxal is a precursor of secondary organic aerosol (SOA). Acetic acid plays a central role in the aqueous oxidation of methylglyoxal and it is a ubiquitous product of gas phase photochemistry, making it a potential "aqueous" SOA precursor in its own right. However, the fate of acetic acid upon aqueous-phase oxidation is not well understood. In this research, acetic acid (20 ?M-10 mM) was oxidized by OH radicals, and pyruvic acid and methylglyoxal experimental samples were analyzed using new analytical methods, in order to better understand the formation of SOA from acetic acid and methylglyoxal. Glyoxylic, glycolic, and oxalic acids formed from acetic acid and OH radicals. In contrast to the aqueous OH radical oxidation of methylglyoxal, the aqueous OH radical oxidation of acetic acid did not produce succinic acid and oligomers. This suggests that the methylgloxal-derived oligomers do not form through the acid catalyzed esterification pathway proposed previously. Using results from these experiments, radical mechanisms responsible for oligomer formation from methylglyoxal oxidation in clouds and wet aerosols are proposed. The importance of acetic acid/acetate as an SOA precursor is also discussed. We hypothesize that this and similar chemistry is central to the daytime formation of oligomers in wet aerosols.

Tan, Y.; Lim, Y. B.; Altieri, K. E.; Seitzinger, S. P.; Turpin, B. J.

2012-01-01

183

Mechanisms leading to oligomers and SOA through aqueous photooxidation: insights from OH radical oxidation of acetic acid and methylglyoxal  

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Full Text Available Previous experiments have demonstrated that the aqueous OH radical oxidation of methylglyoxal produces low volatility products including pyruvate, oxalate and oligomers. These products are found predominantly in the particle phase in the atmosphere, suggesting that methylglyoxal is a precursor of secondary organic aerosol (SOA. Acetic acid plays a central role in the aqueous oxidation of methylglyoxal and it is a ubiquitous product of gas phase photochemistry, making it a potential "aqueous" SOA precursor in its own right. However, the fate of acetic acid upon aqueous-phase oxidation is not well understood. In this research, acetic acid (20 ?M–10 mM was oxidized by OH radicals, and pyruvic acid and methylglyoxal experimental samples were analyzed using new analytical methods, in order to better understand the formation of SOA from acetic acid and methylglyoxal. Glyoxylic, glycolic, and oxalic acids formed from acetic acid and OH radicals. In contrast to the aqueous OH radical oxidation of methylglyoxal, the aqueous OH radical oxidation of acetic acid did not produce succinic acid and oligomers. This suggests that the methylgloxal-derived oligomers do not form through the acid catalyzed esterification pathway proposed previously. Using results from these experiments, radical mechanisms responsible for oligomer formation from methylglyoxal oxidation in clouds and wet aerosols are proposed. The importance of acetic acid/acetate as an SOA precursor is also discussed. We hypothesize that this and similar chemistry is central to the daytime formation of oligomers in wet aerosols.

Y. Tan

2012-01-01

184

Thermodynamic analysis of phenol acylation with acetic acid  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Hidroxiacetofenonas, especialmente o isômero para, são importante compostos da industria farmacêutica. Elas podem ser obtidas por acilação do fenol, mas as propriedades termodinâmicas dessa reação não estão disponíveis. A estimativa das propriedades desta reação, usando o método de Benson, indica qu [...] e a formação das hidroxiacetofenonas é favorável a temperaturas entre 300 K e 800 K. Temperaturas superiores favorecem a formação do acetato de fenila. Neste intervalo de temperatura, a meta-hidroxiacetofenona é mais estável que os isômeros orto e para. Abstract in english Hydroxyacetophenones, especially the para-isomer, are important compounds in the pharmaceutical industry. They can be obtained through acylation of phenol but no data about the thermodynamic properties of this reaction are available. The estimation of the properties of this reaction, using the Benso [...] n method, shows that the formation of hydroxyacetophenones is favorable at temperatures between 300 K and 800 K. Higher temperatures favor the formation of phenyl acetate. In this temperature range, meta-hydroxyacetophenone is more stable than the other isomers.

E. Vitor, Sobrinho; D., Cardoso; E.F., Souza-Aguiar.

185

Photoluminescence properties of poly(thiophene-3yl-acetic acid 8-quinolinyl ester) in solution and in acid medium  

Energy Technology Data Exchange (ETDEWEB)

The photoluminescence characteristics and quantum yields of poly(thiophene-3-yl-acetic acid 8-quinolinyl ester) have been studied. Fluorescence measurements indicate that fluorescence quantum efficiency increases with decreasing the concentration of polymer solution. The quantum yield of the polymer in the solution is higher than that of the Rhodamine B dye at lower concentration. The behaviour of photoluminescence property is studied under different acidic conditions. The fluorescence quenching is observed in the acid medium without any shift in the wavelength.

Maiti, J. [Department of Chemical Sciences, Tezpur University, Tezpur, Assam 784028 (India); Dolui, S.K., E-mail: dolui@tezu.ernet.i [Department of Chemical Sciences, Tezpur University, Tezpur, Assam 784028 (India)

2009-06-15

186

Investigation on Ethylenediaminetetra-Acetic Acid as Corrosion Inhibitor for Mild Steel in 1.0M Hydrochloric Acid  

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The influence of ethylenediaminetetra-acetic acid (EDTA) on the corrosion of mild steel in 1.0 M hydrochloric acid solution was investigated by means of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The efficiency of EDTA was compared with thiourea. Primary results obtained revealed that EDTA performed as good corrosion inhibitor for mild steel in 1.0 M hydrochloric acid media comparing with thiourea. Polarization curves show that the behavior of EDTA and thio...

Musa, Ahmed Y.; Kadhum, Abdul Amir H.; Mohd Sobri Takriff; Abdul Razak Daud; Siti Kartom Kamarudin

2009-01-01

187

Conformational equilibria and large-amplitude motions in dimers of carboxylic acids: rotational spectrum of acetic Acid-difluoroacetic Acid.  

Science.gov (United States)

We report the rotational spectra of two conformers of the acetic acid-difluoroacetic acid adduct (CH3 COOH-CHF2 COOH) and supply information on its internal dynamics. The two conformers differ from each other, depending on the trans or gauche orientation of the terminal ?CHF2 group. Both conformers display splittings of the rotational transitions, due to the internal rotation of the methyl group of acetic acid. The corresponding barriers are determined to be V3 (trans)=99.8(3) and V3 (gauche)=90.5(9) cm(-1) (where V3 is the methyl rotation barrier height). The gauche form displays a further doubling of the rotational transitions, due to the tunneling motion of the ?CHF2 group between its two equivalent conformations. The corresponding B2 barrier is estimated to be 108(2) cm(-1) . The increase in the distance between the two monomers upon OH?OD deuteration (the Ubbelohde effect) is determined. PMID:25056445

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

2014-10-01

188

Batch salicylic acid nitration by nitric acid/acetic acid mixture under isothermal, isoperibolic and adiabatic conditions.  

Science.gov (United States)

Runaway phenomena and thermal explosions can originate during the nitration of salicylic acid by means of a nitric acid/acetic acid mixture when the thermal control is lost, mainly as a result of the formation and thermal decomposition of picric acid. The prediction of the behaviour of this system is thus of great importance in view of possible industrial applications and the need to avoid the occurrence of unwanted dangerous events. During a previous investigation a model was developed to simulate its behaviour when the starting concentration of the substrate is too low, thus, preventing the precipitation of poor soluble intermediates. In this work this model is extended to deal with more concentrated systems even in case of a solid phase separating during the process. To this purpose the previously assessed dependence of the solubility of 3-nitro and 5-nitrosalicylic acids upon temperature and nitric acid concentration is included in the model. It is assumed that when 3-nitro and 5-nitrosalicylic acids are partially suspended in the reacting medium a kinetic regime of "dissolution with reaction" is established; that is, the redissolution of these species is a fast process compared to the successive nitration to give dinitroderivatives. Good results are obtained in the comparison of the experimental data with those calculated both in isoperibolic and adiabatic conditions when the revised model is used. PMID:16842908

Andreozzi, R; Canterino, M; Caprio, V; Di Somma, I; Sanchirico, R

2006-12-01

189

Calibration and intercomparison of acetic acid measurements using proton transfer reaction mass spectrometry (PTR-MS  

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Full Text Available Acetic acid is one of the most abundant organic acids in the ambient atmosphere, with maximum mixing ratios reaching into the tens of parts per billion by volume (ppbv range. The identities and associated magnitudes of the major sources and sinks for acetic acid are poorly characterized, due in part to the limitation in available measurement techniques. This paper demonstrates that Proton Transfer Reaction Mass Spectrometry (PTR-MS can reliably quantify acetic acid vapor in ambient air. Three different PTR-MS configurations were calibrated at low ppbv mixing ratios using permeation tubes, which yielded calibration factors between 7.0 and 10.9 normalized counts per second per ppbv (ncps ppbv?1 at a drift tube field strength of 132 townsend (Td. Detection limits ranged from 0.06 to 0.32 ppbv with dwell times of 5 s. These calibration factors showed negligible humidity dependence. Using the experimentally determined calibration factors, PTR-MS measurements of acetic acid during the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT campaign were validated against results obtained using Mist Chambers coupled with Ion Chromatography (MC/IC. An orthogonal least squares linear regression of paired data yielded a slope of 1.14 ± 0.06 (2?, an intercept of 0.049 ± 20 (2? ppbv, and an R2 of 0.78. The median mixing ratio of acetic acid on Appledore Island, ME during the ICARTT campaign was 0.530 ± 0.025 ppbv with a minimum of 0.075 ± 0.004 ppbv, and a maximum of 3.555 ± 0.171 ppbv.

K. B. Haase

2012-07-01

190

Calibration and intercomparison of acetic acid measurements using proton transfer reaction mass spectrometry (PTR-MS)  

Science.gov (United States)

Acetic acid is one of the most abundant organic acids in the ambient atmosphere, with maximum mixing ratios reaching into the tens of parts per billion by volume (ppbv) range. The identities and associated magnitudes of the major sources and sinks for acetic acid are poorly characterized, due in part to the limitation in available measurement techniques. This paper demonstrates that Proton Transfer Reaction Mass Spectrometry (PTR-MS) can reliably quantify acetic acid vapor in ambient air. Three different PTR-MS configurations were calibrated at low ppbv mixing ratios using permeation tubes, which yielded calibration factors between 7.0 and 10.9 normalized counts per second per ppbv (ncps ppbv?1) at a drift tube field strength of 132 townsend (Td). Detection limits ranged from 0.06 to 0.32 ppbv with dwell times of 5 s. These calibration factors showed negligible humidity dependence. Using the experimentally determined calibration factors, PTR-MS measurements of acetic acid during the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) campaign were validated against results obtained using Mist Chambers coupled with Ion Chromatography (MC/IC). An orthogonal least squares linear regression of paired data yielded a slope of 1.14 ± 0.06 (2?), an intercept of 0.049 ± 20 (2?) ppbv, and an R2 of 0.78. The median mixing ratio of acetic acid on Appledore Island, ME during the ICARTT campaign was 0.530 ± 0.025 ppbv with a minimum of 0.075 ± 0.004 ppbv, and a maximum of 3.555 ± 0.171 ppbv.

Haase, K. B.; Keene, W. C.; Pszenny, A. A. P.; Mayne, H. R.; Talbot, R. W.; Sive, B. C.

2012-01-01

191

Importance of secondary sources in the atmospheric budgets of formic and acetic acids  

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Full Text Available We present a detailed budget of formic and acetic acids, two of the most abundant trace gases in the atmosphere. Our bottom-up estimate of the global source of formic and acetic acids are ~1200 and ~1400 Gmol/yr, dominated by photochemical oxidation of biogenic volatile organic compounds, in particular isoprene. Their sinks are dominated by wet and dry deposition. We use the GEOS-Chem chemical transport model to evaluate this budget against an extensive suite of measurements from ground, ship and satellite-based Fourier transform spectrometers, as well as from several aircraft campaigns over North America. The model captures the seasonality of formic and acetic acids well but generally underestimates their concentration, particularly in the Northern midlatitudes. We infer that the source of both carboxylic acids may be up to 50% greater than our estimate and report evidence for a long-lived missing secondary source of carboxylic acids that may be associated with the aging of organic aerosols. Vertical profiles of formic acid in the upper troposphere support a negative temperature dependence of the reaction between formic acid and the hydroxyl radical as suggested by several theoretical studies.

F. Paulot

2010-10-01

192

Importance of secondary sources in the atmospheric budgets of formic and acetic acids  

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Full Text Available We present a detailed budget of formic and acetic acids, two of the most abundant trace gases in the atmosphere. Our bottom-up estimate of the global source of formic and acetic acids are ~1200 and ~1400 Gmol yr?1, dominated by photochemical oxidation of biogenic volatile organic compounds, in particular isoprene. Their sinks are dominated by wet and dry deposition. We use the GEOS-Chem chemical transport model to evaluate this budget against an extensive suite of measurements from ground, ship and satellite-based Fourier transform spectrometers, as well as from several aircraft campaigns over North America. The model captures the seasonality of formic and acetic acids well but generally underestimates their concentration, particularly in the Northern midlatitudes. We infer that the source of both carboxylic acids may be up to 50% greater than our estimate and report evidence for a long-lived missing secondary source of carboxylic acids that may be associated with the aging of organic aerosols. Vertical profiles of formic acid in the upper troposphere support a negative temperature dependence of the reaction between formic acid and the hydroxyl radical as suggested by several theoretical studies.

F. Paulot

2011-03-01

193

Transformation of acetate carbon into carbohydrate and amino acid metabilites during decomposition in soil  

DEFF Research Database (Denmark)

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 days of incubation, 2.2% of the labelled carbon originally added to the soil was located in carbohydrate metabolites,7% in amino acid metabolites and 5% in the insoluble residue. The carbon in these fractions accounted for 77% of the total, residual, labelled carbon in the soil; 12% in carbohydrates, 40% in amino acids and 25% in the insoluble residue. The remainder was non-indentified, acid-soluble material. The carbohydrate metabolites originating from the labelled carbon decayed at a faster rate than the amino acid metabolites, indicating different protective mechanisms for these materials.

SØrensen, Lasse Holst

1971-01-01

194

Racimisation of (R) –Alpha – Ethyl -2-Oxo-1-Pyrrolidine Acetic acid with Thionyl Chloride  

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We report the new synthetic methodology and Racimisation of (R)-Alpha-ethyl-2-oxo-1-pyrrolidine acetic acid with thionyl chloride resulting compound is charactarised and confirmed by SOR, racimisation is occurs by using thionyl chloride, the resulting of the yield is 83%.

Chandra Sekhara Reddy, K.; Kasi Viswanath, I. V.

2013-01-01

195

GENE EXPRESSION PATTERNS OF CD-1 DAY-8 EMBRYO CULTURES EXPOSED TO BROMOCHLORO ACETIC ACID  

Science.gov (United States)

Gene expression patterns of CD-1 day-8 embryo cultures exposed to bromochloro acetic acid Edward D. Karoly?*, Judith E. Schmid* and E. Sidney Hunter III* ?Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina and *Reproductiv...

196

Rapid and efficient synthesis of [1,2-14C] acetic acid  

International Nuclear Information System (INIS)

The method for the synthesis of mmol quantities of [1,2-14C] acetic acid with molar activity equal to or higher than 3.7 GBqxmmol-1 (100 mCixmmol-1) based on the step hydration and oxidation of [1,2-14C] ethine is described. The 85% radiochemical yield on starting Ba14CO3 was achieved. (author)

197

Population dynamics of acetic acid bacteria during traditional wine vinegar production.  

Science.gov (United States)

The population dynamics of acetic acid bacteria in traditional vinegar production was determined in two independent vinegar plants at both the species and strain level. The effect of barrels made of four different woods upon the population dynamics was also determined. Acetic acid bacteria were isolated on solid media and the species were identified by RFLP-PCR of 16S rRNA genes and confirmed by 16S rRNA gene sequencing, while strains were typed by ERIC-PCR and (GTG)(5)-rep-PCR. The most widely isolated species was Acetobacter pasteurianus, which accounted for 100% of all the isolates during most of the acetification. Gluconacetobacter europaeus only appeared at any notable level at the end of the process in oak barrels from one vinegar plant. The various A. pasteurianus strains showed a clear succession as the concentration of acetic acid increased. In both vinegar plants the relative dominance of different strains was modified as the concentrations of acetic acid increased, and strain diversity tended to reduce at the end of the process. PMID:20117853

Vegas, Carlos; Mateo, Estibaliz; González, Angel; Jara, Carla; Guillamón, José Manuel; Poblet, Montse; Torija, Ma Jesús; Mas, Albert

2010-03-31

198

The structure and pervaporation properties for acetic acid/water of polydimethylsiloxane composite membranes  

International Nuclear Information System (INIS)

Highlights: ? The membranes were prepared using AMEO as a substitute of cross-linker TEOS. ? OMMT was used as filler to improve the pervaporation performance of membrane. ? PDMS-AMEO/OMMT/PES composite membrane was used in acetic acid/water separation. -- Abstract: Polydimethylsiloxane (PDMS)/organic montmorillonite (OMMT)/polyether polyethersulfone (PES) composite membranes were prepared by in situ anionic polymerization using 3-aminopropyltrimethoxy (AMEO) as a crosslinker. The morphology, thermal properties and interaction of PDMSAMEO/OMMT membranes were characterized by using a scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR) and a thermal gravimetric analysis (TGA). The swelling behavior of membranes without PES support was investigated. The effects of AMEO content and OMMT content on separation properties were also studied. The results show that the addition of appropriate OMMT could improve the hydrophobic and pro-acetic acid properties of a membrane. The acetic acid selectivity of membranes was best when AMEO content was 0.1. The membrane, loading 2 wt.% OMMT, exhibited the highest separation factor for a feed concentration of 10 wt.% at 313 K. An increase in feed concentration resulted in the enhancement of flux and selectivity. When the feed concentration was above 20 wt.%, the separation factor of a filled membrane was larger than for an unfilled membrane. With increases in the feed temperature, the permeation flux of membranes increased. However, the acetic acid selectivity of an unfilled membrane decreased but for filled membranes initially increased before decreasing.

199

Stimulation of indole-3-acetic acid production in Rhizobium by flavonoids.  

Science.gov (United States)

Flavonoids activate nod gene expression in Rhizobium resulting in the synthesis of Nod signals which trigger organogenesis in the host plant. This paper shows that nod-inducers also stimulate the production of the phytohormone IAA (indole-3-acetic acid). PMID:2026265

Prinsen, E; Chauvaux, N; Schmidt, J; John, M; Wieneke, U; De Greef, J; Schell, J; Van Onckelen, H

1991-04-22

200

Phase behaviour of aqueous mixtures of acetic acid with isomers of xylene  

International Nuclear Information System (INIS)

Highlights: • The binodal curve and tie line data were obtained for four systems. • These systems are (water + acetic acid + o-xylene, m-xylene, p-xylene or xylenes). • Distribution coefficients and separation factors were measured. • Extraction of acetic acid by mixed xylenes is more suitable. • Experimental LLE data were correlated using NRTL model. -- Abstract: (Liquid–liquid) equilibrium (LLE) data of the solubility curves and tie-line compositions have been determined for mixtures of (water + acetic acid + organic solvent (o-xylene, m-xylene or p-xylene)) at T = 298.15 K and atmospheric pressure. The mixed isomers (xylenes) are also used as a mixed-solvent like the individual isomers and phase behaviour of (water + acetic acid + xylenes) is investigated. The experimental LLE data were correlated using the NRTL model, and the binary interaction parameters were obtained. Distribution coefficients and separation factors have been evaluated for the immiscibility region. The reliability of the experimental tie-lines has been confirmed by using Othmer–Tobias correlation

 
 
 
 
201

Detection of Acetic Acid in wine by means of an electronic nose  

Science.gov (United States)

A portable electronic nose (see Fig.1) based on metal oxide semiconductor thin-film sensors has been developed to detect acetic acid present in four types of wines. The wines analyzed are from the same cellar but are made with different varieties of grapes. Data analysis was performed by two pattern recognition methods: principal component analysis (PCA) and Artificial Neural Networks (ANN).

Lozano, Jesús; Álvarez, Fernando; Santos, José Pedro; Horrillo, Carmen

2011-09-01

202

Evaluating the effect of a mixture of alcohol and acetic acid for otomycosis therapy  

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Full Text Available Introduction and objective: Otomycosis is a fungal infection of external auditory meatus. The acute form of the disease causes secretion and pruritus. The usual prescribed medicines for otomycosis are topical clotrimazole 1%, amphotericin B and otosporin. The aim of the present study was to evaluate the efficacy of treatment with isopropyl alcohol and acetic acid for otomycosis.Materials and methods: In the present study 910 patients examined and those suspected to have otomycosis referred to medical mycology laboratory of Golabchi, Kashan. A questionnaire was also filled for each patient. Both direct and culture examinations were used to confirm otomycosis in the patients. Then the patients were treated with the mixture of isopropyl alcohol+acetic acid. Results: Out of 910 examined patients, 60 patients were suspected to have otomycosis and referred to medical mycology lab. Mycological examinations confirmed otomycosis in 52 patients (86.7%. Most of the patients (78.8% were cured perfectly after therapy with the mixture of alcohol and acetic acid. After three weeks, in addition to elimination of clinical signs further smear showed no sign of disease. However in four patients there was a relapse of the disease.Conclusion: Due to therapeutic effect of the mixture of isopropyl alcohol and acetic acid for otomycosis, its low side effects and low rate of relapse, it is recommended to use this mixture for the treatment of otomycosis.

Ahmad Yaganeh Moghadam

2010-04-01

203

Acidic ionic liquid as "quasi-homogeneous" catalyst for controllable synthesis of cellulose acetate.  

Science.gov (United States)

In this paper, we demonstrated that acidic ionic liquids (ILs) can be used as "quasi-homogeneous" catalysts for the efficient acetylation of cellulose. Unlike existing techniques that use large amount of ILs as solvent to dissolve and acetylate cellulose, a small amount of acidic ILs was used as catalyst in this study to overcome the low efficiency associated with relatively high viscosity and costs of ILs during homogeneous acetylation. Fully substituted cellulose acetate with a conversion of 88.8% was obtained by using only 9mol% IL 1-vinyl-3-(3-sulfopropyl) imidazolium hydrogen sulfate as catalyst, which is much higher than that of common commercialized solid acid catalysts. The degree of substitution and solubility of the obtained cellulose acetate can be facilely controlled by varying the concentration of ILs and reaction time. The dual function of swelling and catalyzing of acidic ILs for the acetylation of cellulose is responsible for the excellent catalytic performance. PMID:25256462

Tian, Dong; Han, Yangyang; Lu, Canhui; Zhang, Xinxing; Yuan, Guiping

2014-11-26

204

Protective Effect of Alpha-lipoic Acid Against Lead Acetate-Induced Oxidative Stress in the Bone Marrow of Rats  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The present study was designed to investigate the effects of alpha Lipoic Acid (LA) against lead acetate induced changes in free radical scavenging enzymes and lipid hydroperoxides in bone marrow of rats. Rats were exposed to lead acetate in their drinking water (500 ppm) for 14 days and alpha lipoic acid was given concurrently (25, 50 and 100 mg kg-1). Blood lead levels, lipid hydroperoxides, protein carbonyl contents and oxidative marker enzymes were estimated. Lead acetate in dr...

Srikumar Chakravarthi; Tan Jackie; Nagaraja Haleagrahara; Anupama Bangra Kulur

2011-01-01

205

Effects of metal and acidic sites on the reaction by-products of butyl acetate oxidation over palladium-based catalysts.  

Science.gov (United States)

Catalytic oxidation is widely used in pollution control technology to remove volatile organic compounds. In this study, Pd/ZSM-5 catalysts with different Pd contents and acidic sites were prepared via the impregnation method. All the catalysts were characterized by means of N2 adsorption-desorption, X-ray fluorescence (XRF), H2 temperature programmed reduction (H2-TPR), and NH3 temperature programmed desorption (NH3-TPD). Their catalytic performance was investigated in the oxidation of butyl acetate experiments. The by-products of the reaction were collected in thermal desorption tubes and identified by gas chromatography/mass spectrometry. It was found that the increase of Pd content slightly changed the catalytic activity of butyl acetate oxidation according to the yield of CO2 achieved at 90%, but decreased the cracking by-products, whereas the enhancement of strong acidity over Pd-based catalysts enriched the by-product species. The butyl acetate oxidation process involves a series of reaction steps including protolysis, dehydrogenation, dehydration, cracking, and isomerization. Generally, butyl acetate was cracked to acetic acid and 2-methylpropene and the latter was an intermediate of the other by-products, and the oxidation routes of typical by-products were proposed. Trace amounts of 3-methylpentane, hexane, 2-methylpentane, pentane, and 2-methylbutane originated from isomerization and protolysis reactions. PMID:25079284

Yue, Lin; He, Chi; Hao, Zhengping; Wang, Shunbing; Wang, Hailin

2014-03-01

206

Preventive activity of ascorbic acid on lead acetate induced cerebellar damaged in adult Wistar rats  

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Among the environmental contaminants, lead is one of the most hazardous to living matter. In mammals, the main target is the central nervous system, particularly in the young. Ascorbic acid is an antioxidant which is a substance that may protect your cells against the effects of free radicals. This study investigated Experiment the protective effect of ascorbic acid on the cerebellum of adult Wistar rats following oral administration of different doses of Lead acetate. Thirty adult Wistar rat...

Sunday Abraham Musa; Iliyasu Musa Omoniye; Wilson Oliver Hamman; Augustine Oseloka Ibegbu; Uduak Emmanuel Umana

2012-01-01

207

Kinetic and safety assessment for salicylic acid nitration by nitric acid/acetic acid system.  

Science.gov (United States)

The nitration process of salicylic acid for the production of the important intermediate 5-nitrosalicylic acid is studied from thermokinetic and safety points of view. Investigations carried out by considering, as process deviations, the loss of the thermal control point out the possibility of runaway phenomena due to the occurrence of polynitration reactions. Isothermal experiments are carried out in various conditions to assess the involved reaction network and reaction kinetics. PMID:16343755

Andreozzi, R; Caprio, V; Di Somma, I; Sanchirico, R

2006-06-30

208

Application of bipolar electrodialysis to E.coli fermentation for simultaneous acetate removal and pH control  

DEFF Research Database (Denmark)

The application of bipolar electrodialysis (BPED) for the simultaneous removal of inhibitory acetate and pH control during E. coli fermentation was investigated. A two cell pair electrodialysis module, consisting of cation exchange, anion exchange and bipolar membranes with working area of 100 cm2 each, was integrated with a standard 7 l stirred tank bioreactor. Results showed that BPED was beneficial in terms of in situ removal of inhibitory acetate and a reduction in the amount NH4OH used for pH control. In batch and fed-batch BPED fermentations, base additions were decreased by up to 50% in both cases compared to electrodialysis (ED) fermentations with pH controlled at 6.7 ± 0.1. Consequently, the final biomass (34.2 g DCW l?1) and recombinant protein (5.5 g l?1) concentrations obtained were increased by up to 37 and 20%, respectively.

Woodley, John

2010-01-01

209

Investigation of organic acids efficacy on rosa bourbonia waste biomass for Pb (II) removal from aqueous streams (abstract)  

International Nuclear Information System (INIS)

In the present study bio sorption technique, the accretion of metal by biomass was used for the removal of lead from aqueous streams. The adsorption characteristics of metal on Rosa bourbonia waste biomass after pretreatments with acetic acid, benzoic acid and citric acid were evaluated as a function of bio sorbent dosage, initial concentration of metal and time. The sorption capacity (mgg /sup -1/) increased with increase in initial Pb(II) ion concentration and maximum q at 400 (mg/L) was 119.92 with original biomass. The acidic pretreatments decreased the metal uptake capacity (mgg/sup -1/) in the order benzoic acid (82.58) > citric acid (70.23) > acetic acid (55.74). The kinetic data revealed that the equilibrium was established within 240 minutes for original as well as for acidically pretreated bio masses. The Langmuir isotherm model and pseudo second order kinetic model fitted well to the Pb (II) bio sorption data. (author)

210

Determination of ethanol in acetic acid-containing samples by a biosensor based on immobilized Gluconobacter cells  

Directory of Open Access Journals (Sweden)

Full Text Available Reshetilov AN, Kitova AE, Arkhipova AV, Kratasyuk VA, Rai MK. 2012. Determination of ethanol in acetic acid containing samples by a biosensor based on immobilized Gluconobacter cells. Nusantara Bioscience 4: 97-100. A biosensor based on Gluconobacter oxydans VKM B-1280 bacteria was used for detection of ethanol in the presence of acetic acid. It was assumed that this assay could be useful for controlling acetic acid production from ethanol and determining the final stage of the fermentation process. Measurements were made using a Clark electrode-based amperometric biosensor. The effect of pH of the medium on the sensor signal and the analytical parameters of the sensor (detection range, sensitivity were investigated. The residual content of ethanol in acetic acid samples was analyzed. The results of the study are important for monitoring the acetic acid production process, as they represent a method of tracking its stages

VALENTINA A. KRATASYUK

2012-11-01

211

Increases in jasmonic acid caused by indole-3-acetic acid and auxin herbicides in cleavers (Galium aparine).  

Science.gov (United States)

The effects of indole-3-acetic acid and auxin herbicides on endogenous jasmonic acid (JA) concentrations were studied in relation to changes in ethylene and abscisic acid (ABA) levels in cleavers (Galium aparine). When plants were root-treated with increasing concentrations of indole-3-acetic acid (IAA), ethylene biosynthesis was stimulated in response to the accumulation of endogenous IAA in the shoot tissue. Within 25h of treatment, stimulated ethylene formation was accompanied by increases in immunoreactive concentrations of JA and ABA, which reached maxima of 4.5-fold and 26-fold of the control, respectively, at 100 microM of applied IAA. Corresponding effects were obtained using synthetic auxins and when the ethylene-releasing compound ethephon was applied exogenously. This represents the first report, to our knowledge, of an auxin-mediated increase in JA levels. The increase in JA may be triggered by ethylene. PMID:15310070

Grossmann, Klaus; Rosenthal, Cindy; Kwiatkowski, Jacek

2004-07-01

212

Oxygen-dependent catabolism of indole-3-acetic acid in Bradyrhizobium japonicum.  

DEFF Research Database (Denmark)

Some strains of Bradyrhizobium japonicum have the ability to catabolize indole-3-acetic acid (IAA). Examination of this catabolism in strain 110 by in vivo experiments has revealed an enzymatic activity catalyzing the degradation of IAA and 5-hydroxy-indole-3-acetic acid. The activity requires addition of the substrates for induction and is oxygen dependent. The highest activity is obtained when the concentration of inducer is 0.2 mM. Spectrophotometric data are consistent with the suggestion that the indole ring is broken during degradation of IAA. We hypothesize that the enzyme catalyzes an oxygen-consuming opening of the indole ring analogous to the one catalyzed by tryptophan 2,3-dioxygenase. The pattern of metabolite usage by known tryptophan-auxotrophic mutants and studies of metabolites by high-performance liquid chromatography indicate that anthranilic acid is a terminal degradation product in the proposed pathway. Udgivelsesdato: 1991-Aug

Egebo, L A; Nielsen, S V

1991-01-01

213

Formic and acetic acid over the central Amazon region, Brazil. I - Dry season  

Science.gov (United States)

The concentrations of formic and acetic acids in the gas phase, atmospheric aerosol, and rainwater samples collected in Amazonia at ground level and in the atmosphere during the Amazon Boundary Layer Experiment in July/August 1985 were analyzed by ion exchange chromatography. The diurnal behavior of both acids at ground level and their vertical distribution in the forest canopy point to the existence of vegetative sources as well as to production by chemical reactions in the atmosphere. The concentrations of formic and acetic acids in the gas phase were about 2 orders of magnitude higher than the corresponding concentrations in the atmospheric aerosol. In rainwater, the total formate and acetate represented about one half of the anion equivalents, in contrast to less than 10 percent of the soluble anionic equivalents contributed by these acids in the atmospheric aerosol. The observed levels of these ions in rainwater are considered to be the result of a combination of chemical reactions in hydrometeors and the scavenging of the gaseous acids by cloud droplets.

Andreae, M. O.; Andreae, T. W.; Talbot, R. W.; Harriss, R. C.

1988-01-01

214

Study on dissociation and solvation in water-acetic acid mixtures  

International Nuclear Information System (INIS)

The addition of acetic acid to water produces media of varying dielectric constant. The concepts of dissociation and solvation were defined in water-acetic acid mixtures containing from 5 per cent to 100 per cent water. The extent to which the activity of water and that of acetic acid participate in the solvation of molecules and of ions was demonstrated. The variation in the dissociation constants of HClO4, HCl and BH+ type acids and that of the ionic products can be interpreted by considering only the activity of the components of the mixture. These constants verify simple empirical relationships of the type pK = = Cte - p log (aH2O) - q log (aHOAc). By estimating the activity coefficients of ion and molecule solvation it was possible to determine their respective influences on the dissociation constants, of BH+ cationic acids. Thus the effect of medium on the constants appears as the sum of separate effects of medium of the chemical species B, H and BH+ taking part, in the reactions. Solvation of the B molecules and of the BH+ ions therefore depends to a large extent on the nature of the base. A study of the redox function R0 defined by Strehlow enabled the activity coefficients of solvation of the ions H+, Ag+, Cl-, Br- and I- to be determined. In the case of protons, the methods of Latimer and Izmailov lead to experimental results very similar to those obtained by the Strehlow's method. (author)

215

[Conversion of acetic acid to methane by thermophiles]. Progress report, May 15, 1989--May 14, 1993  

Energy Technology Data Exchange (ETDEWEB)

The primary goal of this project is to obtain a better understanding of thermophilic microorganisms which convert acetic acid to CH{sub 4}. The previous funding period represents a departure from earlier research in this laboratory, which was more physiological and ecological. The present work is centered on the biochemistry of the thermophile Methanothrix sp. strain CALS-1. this organism presents a unique opportunity, with its purity and relatively rapid growth, to do comparative biochemical studies with the other major acetotrophic genus Methanosarcina. We previously found that Methanothrix is capable of using acetate at concentrations 100 fold lower than Methanosarcina. This finding suggests that there are significant differences in the pathways of methanogenesis from acetate in the two genera.

Zinder, S.H.

1993-06-01

216

An Improved Ion Chromatography Methods for Analysis of Acetic and Formic Acid Vapours  

Directory of Open Access Journals (Sweden)

Full Text Available Air quality monitoring for acetic and formic acid vapours inmuseum galleries and storage environments is commonlyconducted using passive sampling and ion chromatography(IC. We report development of a rapid IC method with 2 to60-fold improvement in detection limits for acetate and formate. Baseline resolution is achieved in 4.5 min using anAS11-HC anion exchange column with 4 mM NaOH eluent at1.5 mL/min flow rate. The detection limits are 12 µg/mL(0.24 ng for acetate and 11 µg/mL (0.21 ng for formate.The method was successfully used for air quality monitoring in a Los Angeles museum warehouse.

Robyn E. Hodgkins

2011-01-01

217

Solubilities of {?-D-glucose in water + (acetic acid or propionic acid)} mixtures at atmospheric pressure and different temperatures  

International Nuclear Information System (INIS)

Highlights: • The solubility of ?-D-glucose in binary mixtures has been obtained in this work. • The solubility decreases with the increase of volume fraction of water in the solvents. • The solubility of ?-D-glucose increases with the increase of temperature. • The results show that the three models agree well with the experimental data. • The Apelblat equation was more accurate than the ?h model and ideal model. -- Abstract: Using dynamic method and the laser monitoring observation technique, the solubility of ?-D-glucose in {water + (acetic acid or propionic acid)} was measured over the temperature range (297.55 to 331.45) K at atmospheric pressure. Its corresponding (solid + liquid) equilibrium data will provide essential support for industrial design and further theoretical studies. The solubility of ?-D-glucose in the mixtures of (water + acetic acid), and (water + propionic acid) was found to increase with increasing temperature and decrease with increasing volume fractions of acetic acid, and propionic acid in aqueous solution. The experimental data were correlated by using the Apelblat equation, the ?h equation and the ideal solution equation. The results showed that these three models agreed well with the experimental values, and the Apelblat equation was found to regress the solubility data better than the other two models

218

Estimation of glomerular filtration rate using chromium-51 ethylene diamine tetra-acetic acid and technetium-99m diethylene triamine penta-acetic acid  

International Nuclear Information System (INIS)

Simultaneous measurements of the clearance rate of chromium-51 ethylene diamine tetra-acetic acid (51Cr-EDTA) and technetium-99m diethylene triamine penta-acetic acid (99mTc-DTPA) were performed in 54 patients with a range of function between 9 and 176 ml/min. Using multiple blood samples the two clearance values correlated well (r = 0.97, SEE 8.6 ml/min) and DTPA clearance was higher by 2.9%. For each radiopharmaceutical the plasma clearance rates obtained using multiple blood samples were compared with those obtained with simplified methods, i.e., the 60-180 min two-sample method of Russell and the mono-exponential method with the Brochner-Mortensen correction. For both radiopharmaceuticals the clearance values correlated well with the Russell method (r = 0.99, SEE = 4.1 ml/min for EDTA; r = 0.99, SEE 4.9 ml/min for DTPA) and the mono-exponential method (r = 0.99, SEE 3.6 ml/min for EDTA; r = 0.99, SEE 3.9 ml/min for DTPA). The mean plasma clearance obtained using multiple blood samples did not differ significantly from that obtained with the Russell method, either in patients with a glomerular filtration rate (GFR)99mTc-DTPA is accurate enough for routine clinical use. (orig.)

219

Development of new GABA uptake inhibitors derived from proline or from pyrrolidin-2-yl acetic acid  

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GABA transporters GAT-1, GAT-2 and GAT-3 are new targets for drug design. The substitution of the nitrogen atoms in Nicopetic acid (11), Guvacine (12) and cis-4- Hydroxynicopetic acid (13) with appropriate bulky lipophilic groups resulted in very potent GABA uptake inhibitors for GAT-1 as well as for GAT-3. Pyrrolidine-2-acetic acid derivatives with the three N-substituents 24a-c (Scheme 54) also showed a highly potent inhibition at GAT-1 and GAT-3, respectively. My intentio...

Zhao, Xueqing

2002-01-01

220

Fatty acid synthesis in human testis incubated with [1-14C] acetate  

International Nuclear Information System (INIS)

Slices of human testes were incubated for 3 h with [1-14C]-acetate, and the lipids extracted and analysed. The total incorporation of 14C into the total fatty acids of 23 samples was 3.7 +- 0.22% (S.E.M.) of the substrate per g tissue. There was no consistent detectable variation with age or with the spermatogenic rating of the tissue. The distribution of radioactivity in individual fatty acids of the incubated testes, in hydrogenated derivatives and in various classes of lipids showed that the tissue could both synthesize fatty acids and incorporate them into complex lipids. (U.K.)

 
 
 
 
221

Electron spin resonance studies of barriers to hindered rotation in acetic acid, acetamide, and peptide radicals  

International Nuclear Information System (INIS)

Activation energies for methyl group rotation in the radicals of type H3C-C2O) as well as in 8 M NaOD glasses have produced the acetic acid anion, the acetate dianion, and the acetamide anion. ESR spectra of these have revealed a doublet (ca. 32G) at 90 K reversibly interconverting to a 1:3:3:1 quartet, of ca. 15-G hyperfine splitting, at higher temperatures (170 K). This interconversion has been attributed to the hindered internal rotation of the methyl group about the H3C-C< bond. The ESR spectra are analyzed using modified Bloch equations for the three-jump process. The mean lifetime (tau) at each temperature (T) has been estimated by a comparison of experimental and simulated ESR spectra. The activation energy (E/sub a/) for the sixfold barrier to the rotation is found to be 5.0 +- 0.5 kcal/mol in the acetate dianion and is about 3.0 kcal/mol for the acetate and acetamide as well as N-acetylamino acids. ESR spectra characteristic of the tunneling methyl group were observed at low temperature (20 K< T<100K) for the radicals produced in ?-irradiated polycrystalline samples of glycyl-L-alanine and L-alanyl-L-alanine. 3 figures, 1 table

222

Dynamics of three organic acids (malic, acetic and succinic acid) in sunflower exposed to cadmium and lead.  

Science.gov (United States)

Sunflower (Helianthus annuus L.) has been considered as a good candidate for bioaccumulation of heavy metals. In the present study, sunflower was used to enrich the cadmium and lead in sand culture during 90 days. Biomass, Cd and Pb uptake, three organic acids and pH in cultures were investigated. Results showed that the existence of Cd and Pb showed different interactions on the organic acids exudation. In single Cd treatments, malic and acetic acids in Cd10 showed an incremental tendency with time. In the mixed treatments of Cd and Pb, malic acids increased when 10 and 40 mg x L(-1) Cd were added into Pb50, but acetic acids in Pb50 were inhibited by Cd addition. The Cd10 supplied in Pb10 stimulated the secretion of malic and succinic acids. Moreover, the Cd or Pb uptake in sunflower showed various correlations with pH and some organic acids, which might be due to the fact that the Cd and Pb interfere with the organic acids secretion in rhizosphere of sunflower, and the changes of organic acids altered the form and bioavailability of Cd and Pb in cultures conversely. PMID:23819268

Niu, Zhixin; Li, Xiaodong; Sun, Lina; Sun, Tieheng

2013-01-01

223

Influence of Acidic pH on Hydrogen and Acetate Production by an Electrosynthetic Microbiome  

Science.gov (United States)

Production of hydrogen and organic compounds by an electrosynthetic microbiome using electrodes and carbon dioxide as sole electron donor and carbon source, respectively, was examined after exposure to acidic pH (?5). Hydrogen production by biocathodes poised at ?600 mV vs. SHE increased>100-fold and acetate production ceased at acidic pH, but ?5–15 mM (catholyte volume)/day acetate and>1,000 mM/day hydrogen were attained at pH ?6.5 following repeated exposure to acidic pH. Cyclic voltammetry revealed a 250 mV decrease in hydrogen overpotential and a maximum current density of 12.2 mA/cm2 at ?765 mV (0.065 mA/cm2 sterile control at ?800 mV) by the Acetobacterium-dominated community. Supplying ?800 mV to the microbiome after repeated exposure to acidic pH resulted in up to 2.6 kg/m3/day hydrogen (?2.6 gallons gasoline equivalent), 0.7 kg/m3/day formate, and 3.1 kg/m3/day acetate (?=?4.7 kg CO2 captured).

LaBelle, Edward V.; Marshall, Christopher W.; Gilbert, Jack A.; May, Harold D.

2014-01-01

224

Influence of Bacillus subtilis and acetic acid on Cobb500 intestinal microflora.  

Directory of Open Access Journals (Sweden)

Full Text Available The beneficial modes of probiotic action include regulation of intestinal microbial homeostasis, stabilization of the gastrointestinal barrier function expression of bacteriocins and interference with the ability of pathogens to colonize and infect the mucosa. Organic acids as feed additives have been used to reduce or eliminate pathogenic bacteria and fungal contamination, control microbial growth and reduction of microbial metabolites. The aim of this study was to determine the effect of Bacillus subtilis, acetic acid and their combination on the intestinal microflora of broiler chickens (Cobb 500. The experiment was carried out on 4 groups each contains 100 chicks as follows: control (without addition, treatment 1 (acetic acid, treatment 2 (Bacillus subtilis and treatment 3 (acetic acid + Bacillus subtilis. Six samples from each group were selected as a sample (mixed sex. The highest average number of log CFU.g-1 Lactobacillus sp. was in the treatment 3 – 7.11 log CFU.g-1 and the lowest was in the control group – 6.85. The highest average number of log CFU.g-1 Enterococcus sp. was in the treatment 2 – 7.17 log CFU.g-1 and the lowest was in the control group – 5.65. In both observing additions of Bacillus subtilis and acetic acid increase the number of log CFU.g-1 Lactobacillus sp. and Enterococcus sp. compared with control group. The lower average number of log CFU.g-1 coliform bacteria was in the treatment 2 – 5.9 log CFU.g-1 and the higher was in control group – 6.98. The additional supplement decreased the number of log CFU.g-1 coliform bacteria in the treatment groups compared with the control.

Martin Král

2014-11-01

225

Isolation of residual lignin from softwood kraft pulp. Advantages of the acetic acid acidolysis method.  

Science.gov (United States)

Lignin in kraft pulp was extracted by enzymatic hydrolysis of the carbohydrates, acidolysis with dioxane-water-HCl (conventional method), and acidolysis with acetic acid-water-ZnCl2. The latter method was shown to extract lignin with a better yield than for conventional acidolysis and with a much lower content in impurities than for enzymatic hydrolysis. It was confirmed by 13C NMR analysis of the lignin samples that conventional hydrolysis modified the lignin polymer, causing the cleavage of some aryl-ether linkages. The cleavage was also observed on a model compound submitted to the same extraction conditions. In that respect, the acetic acid-water-ZnCl2 method was less damaging and consequently more suitable for analytical purposes. PMID:15587082

Lachenal, Dominique; Mortha, Gérard; Sevillano, Rose-Marie; Zaroubine, Michail

2004-01-01

226

Acetic Acid Formation by Selective Aerobic Oxidation of Aqueous Ethanol over Heterogeneous Ruthenium Catalysts  

DEFF Research Database (Denmark)

Heterogeneous catalyst systems comprising ruthenium hydroxide supported on different carrier materials, titania, alumina, ceria, and spinel (MgAl2O4), were applied in selective aerobic oxidation ethanol to form acetic acid, an important bulk chemical and food ingredient. The catalysts were characterized by X-ray powder diffraction (XRPD), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and nitrogen physisorption and utilized in the oxidation of 2.5–50 wt % aqueous ethanol solutions at elevated temperatures and pressures. The effects of Ru metal loading, pretreatment of catalysts, oxidant pressure, reaction temperature, and substrate concentration were investigated. Quantitative yield of acetic acid was obtained with 1.2 wt % Ru(OH)x/CeO2 under optimized conditions (150 °C, 10 bar O2, 12 h of reaction time, 0.23 mol % Ru to substrate).

Gorbanev, Yury; Kegnæs, SØren

2012-01-01

227

Anticoccidial effects of acetic acid on performance and pathogenic parameters in broiler chickens challenged with Eimeria tenella  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The objective of the present study was to evaluate the anticoccidial effect of the different concentrations of the acetic acid in the broiler chickens in comparison with the amprolium anticoccidial. A total of 198 chicks were placed 11 per pen with three pens per treatment. The different concentrati [...] ons (1%, 2% and 3%) of acetic acid and amproilum (at the dose rate of 125ppm) were given to the experimental groups in drinking water from 10-19th days of age. One group was kept as infected non medicated control and one as non infected non medicated control. All the groups were inoculated orally with 75,000 sporulated oocysts at the 12th day of age except non infected non medicated control. Anticoccidial effect was evaluated on the basis of performance (weight gain, feed conversion ratio) and pathogenic (oocyst score, lesion score and mortality %age) parameters. Among acetic acid medicated groups, the maximum anticoccidial effect was seen in the group medicated with 3% acetic acid followed by 2% and 1% acetic acid medicated groups. Amprolium and 3% acetic acid were almost equivalent in suppressing the negative performance and pathogenic effects associated with coccidiosis (Eimeria tenella) challenge. In summary, acetic acid has the potential to be used as alternative to chemotherapeutic drugs for Eimeria tenella control. Concentration-dependent anticoccidial effect of acetic acid suggests that further studies should be carried out to determine the possible maximum safe levels of acetic acid with least toxic effects to be used as anticoccidial.

Rao Z., Abbas; Shokat H., Munawar; Zahid, Manzoor; Zafar, Iqbal; Muhammad N., Khan; Muhammad K., Saleemi; Muhammad A., Zia; Arfan, Yousaf.

2011-02-01

228

Suspended biofilm carrier and activated sludge removal of acidic pharmaceuticals  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Removal of seven active pharmaceutical substances (ibuprofen, ketoprofen, naproxen, diclofenac, clofibric acid, mefenamic acid, and gemfibrozil) was assessed by batch experiments, with suspended biofilm carriers and activated sludge from several full-scale wastewater treatment plants. A distinct difference between nitrifying activated sludge and suspended biofilm carrier removal of several pharmaceuticals was demonstrated. Biofilm carriers from full-scale nitrifying wastewater ...

Fala?s, Per; Baillon-dhumez, Aude; Andersen, Henrik Rasmus; Ledin, A.; La Cour Jansen, Jes

2011-01-01

229

Investigation on Ethylenediaminetetra-Acetic Acid as Corrosion Inhibitor for Mild Steel in 1.0M Hydrochloric Acid  

Directory of Open Access Journals (Sweden)

Full Text Available The influence of ethylenediaminetetra-acetic acid (EDTA on the corrosion of mild steel in 1.0 M hydrochloric acid solution was investigated by means of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS. The efficiency of EDTA was compared with thiourea. Primary results obtained revealed that EDTA performed as good corrosion inhibitor for mild steel in 1.0 M hydrochloric acid media comparing with thiourea. Polarization curves show that the behavior of EDTA and thiourea are mixed-type inhibitors. EIS shows that the control step for corrosion process is a charge transfer mechanism.

Ahmed Y. Musa

2009-03-01

230

On the unusual IR spectra of the acetic acid-trimethylamine complex in low temperature matrices  

Science.gov (United States)

Usually the stretching vibration of the A-H group in hydrogen-bonded complexes gives an intense, broad absorption in the IR spectrum. However in a few complexes it has proved difficult to detect this absorption in low temperature matrices. In this work the Ratajczak-Yaremko vibrational model of the hydrogen bond has been applied to simulate the IR spectrum obtained for one such complex: the acetic acid-trimethylamine, ACA-TMA, hydrogen bonded complex isolated in an argon matrix.

Ratajczak, Henryk; Wierzejewska, Maria; Barnes, Austin J.; Yaremko, Anatoly M.; Virko, Serdej V.

2014-06-01

231

Applications of noninvasive physiological sensing to measure indole acetic acid transport  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The primary regulatory phytohormone, indole acetic acid (IAA), plays a crucial role in the growth and development of plants. The polar transport of this hormone is essential to processes such as vascular differentiation, organogenesis, apical dominance, and the tropic effects. Due to the importance of this growth regulator, the development of physiologically relevant methods to measure IAA transport is greatly needed.^ Basipetal IAA transport moves through root epidermal cells that are high...

Diggs, Alfred Ramon

2011-01-01

232

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

Ahmed Ibrahim1, Vibeke Rasch2, Eero Pukkala3, Arja R Aro11Unit for Health Promotion Research, University of Southern Denmark, Esbjerg, Denmark; 2Department of Obstetrics and Gynecology, Odense University Hospital, Odense, Denmark; 3Institute for Statistical and Epidemiological Cancer Research, Finnish Cancer Registry, Helsinki, FinlandObjectives: To assess the risk factors of cervical cancer and the feasibility and acceptability of a visual inspection with acetic acid (VIA) screening method i...

Ibrahim A; Rasch V; Pukkala E; Ar, Aro

2011-01-01

233

Kinetics of the vapor-phase synthesis of allyl acetate (AA) from propylene and acetic acid over palladium-based catalysts  

Energy Technology Data Exchange (ETDEWEB)

The kinetics of the vapor-phase synthesis of allyl acetate (AA) from propylene and acetic acid over palladium-based catalysts containing 5% by wt of a complex palladium acetate Pd(NH/sub 3/)/sub 4/(CH/sub 3/COO)/sub 2/ and 2.5, 5, and 5% of copper, zinc, and sodium acetates, respectively, supported on active alumina thermally treated at 900/sup 0/C were studied in a flow reactor at 180/sup 0/-210/sup 0/C and partial pressures of propylene, oxygen, and acetic acid 1.875-4.83, 0.06-0.35, and 0.1-0.72 atm, respectively. Separate experiments showed that carbon dioxide, formed at 2-2.5% under the conditions studied, was a product of the catalytic oxidation of propylene. The rate of AA synthesis was first order in oxygen, and that of CO/sub 2/ formation was second order in oxygen and minus first order in propylene. Kinetic equations for these reactions were derived by assuming a mechanism similar to one previously proposed for propylene oxychlorination to allyl chloride over palladium-copper chloride catalysts, and a reaction scheme was proposed involving the formation of polyfunctional active sites of a PdCu/sub m/(CH/sub 3/COO)/sub n/ type, which react with proplyene to give AA and (after conversion to an oxidized form) with propylene to form CO/sub 2/.

Mardzhanyan, G.G.; Khachatryan, S.S.; Avetisov, A.K.; Gelbshtein, A.I.; Boyadzhyan, V.K.; Stepanyan, G.G.

1980-06-01

234

Antibacterial power of sodium hypochlorite combined with surfactants and acetic Acid.  

Science.gov (United States)

The aim of this ex vivo study was to compare the antibacterial power of 1% NaOCl with 1% acetic acid, 5.25% NaOCl and two commercially available NaOCl modified with surfactants in bovine root dentin. A total of 120 dentin tubes prepared from intact bovine incisors were infected for 21 days with Enterococcus faecalis and randomly divided into six groups as follows: 5.25%NaOCl; Hypoclean; Chlor-Xtra; 1% NaOCl with 1% acetic acid; infected dentin tubes (positive control); and sterile dentin tubes (negative control). At experimental times of 0, 7, 14, 21 and 28 days, dentin chips were collected using sequential round burs with increasing diameters in separate test tubes containing 3 mL of freshly prepared BHI. Statistical analysis were performed using parametric methods (one-way ANOVA, and Bonferroni's multiple comparisons test, ?=0.01). After culturing, the number of colony-forming units (CFU) was counted. All the NaOCl solutions showed small number of CFU over 28 days. ChlorXtra and Hypoclean had the smallest number of CFU at all times with greater antimicrobial efficacy than 5.25% NaOCl and 1% NaOCl solution with 1% acetic acid. PMID:25250491

Giardino, Luciano; Estrela, Carlos; Mohammadi, Zahed; Palazzi, Flavio

2014-01-01

235

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

DEFF Research Database (Denmark)

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 0.45 with respect to acetaldehyde, and the apparent activation energy was 33.8kJ/mol. The proposed oxidation of acetaldehyde with hydroxyl in the elementary rate determining step is consistent with these both. Density Functional Theory (DFT) calculations show the preference of water cleavage at the Cu step sites. In light of this, an observed intrinsic activity difference between whole catalyst pellets and crushed pellets may be explained by the Cu crystal size and growth rate being functions of the catalyst particle size and time.

Voss, Bodil; SchjØdt, Niels Christian

2011-01-01

236

Exhaled breath concentrations of acetic acid vapour in gastro-esophageal reflux disease.  

Science.gov (United States)

The objective of this experimental study was to discover volatile metabolites present in exhaled breath that could be used as biomarkers of gastro-esophageal reflux disease, GERD, one of the most common causes of chronic cough. An in vitro model based on pork tissue samples exposed to a challenge by artificial gastric fluid was used to identify specific volatile compounds to be chosen for quantification in directly exhaled breath of GERD patients and controls using selected ion flow tube mass spectrometry, SIFT-MS. GC/MS analyses of the headspace of this in vitro model indicated that the only volatile compound significantly increased was acetic acid. End expiratory concentration of acetic acid measured by SIFT-MS in mouth exhaled breath of 22 GERD patients (median 85 ppbv) was found to be significantly higher than that in breath of a control group (median 48 ppbv). Breath acetic acid may be useful for non-invasive diagnostics of GERD and other conditions resulting in the lowering of pH of the lining of the airways. PMID:25189108

Dryahina, Kseniya; Pospíšilová, Veronika; Sovová, Kristýna; Shestivska, Violetta; Kubišta, Ji?í; Spesyvyi, Anatolii; Pehal, František; Turzíková, Jarmila; Votruba, Ji?í; Span?l, Patrik

2014-09-01

237

Mechanical behavior of alumina and alumina-feldspar based ceramics in an acetic acid (4%) environment  

International Nuclear Information System (INIS)

This study investigates the mechanical properties of alumina-feldspar based ceramics when exposed to an aggressive environment (acetic acid 4%). Alumina ceramics containing different concentrations of feldspar (0%, 1%, 5%, 10%, or 40%) were sintered at either 1300, 1600, or 1700 oC. Flaws (of width 0%, 30%, or 50%) were introduced into the specimens using a saw. Half of these ceramic bodies were exposed to acetic acid. Their flexural strength, KIC, and porosity were measured and the fractured samples were evaluated using scanning electronic- and optical microscopy. It was found that in the ceramic bodies sintered at 1600 oC, feldspar content up to 10% improved flexural strength and KIC, and reduced porosities. Generally, it was found that acetic acid had a weakening effect on the flexural strength of samples sintered at 1700 oC but a beneficial effect on KIC of ceramics sintered at 1600 oC. It was concluded that alumina-based ceramics with feldspar content up to 10% and sintered at higher temperatures would perform better in an aggressive environment similar to oral cavity.

238

Investigation of acetic acid-catalyzed hydrothermal pretreatment on corn stover  

DEFF Research Database (Denmark)

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 and tested in terms of the recoveries of glucan and xylan from both the liquor fractions and the WIS, toxicity level of the liquors, and the convertibility of WIS to ethanol. The highest glucan recoveries was found to be 97.42% and 97.94% when 15 and 30 g AA/kg RCS were employed, respectively. The highest xylan recovery of 81.82% was observed by the pretreatment with 10 g AA/kg RCS. The toxic test on liquors showed that the inhibition effect happened to Baker's yeast when the acetic acid used in the pretreatment was higher than 100 g/kg RCS. The WIS obtained from the pretreatment with 15 g and 30 g/kg RCS were subjected to enzymatic hydrolysis and more easily converted to ethanol by Baker's yeast, which gave the ethanol concentration of 33.72 g/L and 32.06 g/L, respectively, higher than 22.04 g/L which was from the non-catalyzed LHW pretreatment (195 °C, 15 min). The ethanol concentration from the RCS was only 8.02 g/L.

Xu, Jian; Thomsen, Mette Hedegaard

2010-01-01

239

Improving the environmental profile of wood panels via co-production of ethanol and acetic acid.  

Science.gov (United States)

The oriented strand board (OSB) biorefinery is an emerging technology that could improve the building, transportation, and chemical sectors' environmental profiles. By adding a hot water extraction stage to conventional OSB panel manufacturing, hemicellulose polysaccharides can be extracted from wood strands and converted to renewably sourced ethanol and acetic acid. Replacing fossil-based gasoline and acetic acid has the potential to reduce greenhouse gas (GHG) emissions, among other possible impacts. At the same time, hemicellulose extraction could improve the environmental profile of OSB panels by reducing the level of volatile organic compounds (VOCs) emitted during manufacturing. In this study, the life cycle significance of such GHG, VOC, and other emission reductions was investigated. A process model was developed based on a mix of laboratory and industrial-level mass and energy flow data. Using these data a life cycle assessment (LCA) model was built. Sensitive process parameters were identified and used to develop a target production scenario for the OSB biorefinery. The findings suggest that the OSB biorefinery's deployment could substantially improve human and ecosystem health via reduction of select VOCs compared to conventionally produced OSB, gasoline, and acetic acid. Technological advancements are needed, however, to achieve desirable GHG reductions. PMID:21967719

Earles, J Mason; Halog, Anthony; Shaler, Stephen

2011-11-15

240

Antireflectance coating on shielding window glasses using glacial acetic acid at ambient temperature  

International Nuclear Information System (INIS)

High density lead glasses having thickness of several centimeters and large dimensions are used as shielding windows in hot cells. To improve visibility, the reflection of light from its optically polished surfaces needs to be minimized to improve transmission as absorption of light in the thick glasses can not be avoided. Antireflectance coating of a material having low refractive index is required for this purpose. Selective leaching of lead at ambient temperature in glacial acetic acid develops a silica rich leached layer on glass surface. Since silica has low refractive index, the leached layer serves as antireflectance coating. Two optically polished discs of shielding window glasses were leached in glacial acetic acid at ambient temperature for 2, 5 and 10 days and their reflectance and transmittance spectra were taken to find effect of leaching. For transparent glass transmittance could be improved from 78.76% to 85.31% after 10 days leaching. Reflectance from the glass could be decreased from 12.48 to 11.67%. For coloured glass transmittance improved from 87.77% to 88.24% after 5 days leaching while reflectance decreased from 12.28% to 5.6% during same period. Based on data generated, 10 days leaching time is recommended for developing anti reflectance coating on transparent shielding window glass and 5 days for coloured shielding window glass. The procedure can be used for shielding windows of any dimensions by fabrication a PVC tank of slightly high dimensions and filling with acetic acid (author)

 
 
 
 
241

2,2,3-trimethylbutane and differently-branched hydrocarbons through hydrogenation of trialkyl acetic acid  

Energy Technology Data Exchange (ETDEWEB)

This report described a method of producing Triptan (2,2,3-trimethylbutane). The starting material was diisopropyl ketone (Isobutyron). It was transformed into dimethylisopropyl acetic acid by first chlorinating the starting material and then treating it with a water-free alkali (sodium hydroxide) in a benzene solution containing a small amount of sodium metal to tie up any remaining water. The acid crystallized out as a sodium salt and then was redissolved with dilute hydrochloric acid. The dimethylisopropyl acetic acid had the same carbon skeleton as Triptan. Studies were underway on finding the best catalyst to accomplish the hydrogenation of the acid group to give Triptan. The best catalyst tried so far was catalyst 6718, a non-splitting catalyst containing nickel sulfide and tungsten sulfide in the ratio 1:1. That catalyst gave yields of 40% Triptan, 40% unchanged acid, 10% higher-boiling-point compounds, and 10% lower-boiling-point liquids and gases. It was supposed that a catalyst with nickel:tungsten ratio of 2:1 instead of 1:1 would have even better effects. Other catalysts were also being investigated. The starting material isobutyron was obtained as a byproduct of butyl alcohol production. The chlorination of Isobutyron was done by introducing chlorine gas into the material while the material was being held at 0/sup 0/ to 5/sup 0/C. Care had to be taken to stop the chlorination at the right time so that only the monochlorinated product was obtained.

Bueren, H.

1944-02-15

242

40 CFR 721.2076 - D-Glucuronic acid, polymer with 6-deoxy-L-mannose and D-glucose, acetate, calcium magnesium...  

Science.gov (United States)

...D-Glucuronic acid, polymer with 6-deoxy-L-mannose and D-glucose, acetate, calcium magnesium...D-Glucuronic acid, polymer with 6-deoxy-L-mannose and D-glucose, acetate, calcium magnesium...D-Glucuronic acid, polymer with 6-deoxy-L-mannose and D-glucose, acetate,...

2010-07-01

243

Radiolabeled acetate kinetics and tricarboxylic acid cycle flux in the rat heart  

International Nuclear Information System (INIS)

Positron-emitting [1-11C]acetate has been proposed as a tracer for noninvasive study of regional myocardial oxidative metabolism in humans with positron emission tomography (PET). To examine the relationship between tissue tracer kinetics and tricarboxylic acid (TCA) cycle flux, [1-14C]acetate was administered as a bolus to Langendorf-perfused rat hearts and effluent 14CO2 and labeled metabolites measured. 14CO2 cleared monoexponentially between 5 and 25 min post administration, representing 90-97% of total effluent 14C activity. In control hearts, perfused with glucose 5 mM and insulin, 10 mU/ml t1/2 for 14CO2 clearance was 3.4 +/- 0.2 min (n=5). TCA cycle flux, estimated from substrate utilization rates correlated linearly with 1/t1/2 when MVO2 was varied over a 3-fold range by hypoxia, KCl arrest, and substrate and hormone addition to the perfusate, indicating that the rate of [1-11C] acetate clearance from myocardium detected by PET may allow in vivo estimation of TCA cycle flux. [1-14C] palmitate administration under control conditions demonstrated similar initial 14CO2 clearance but infusion of lactate, 2 mM, believed to inhibit fatty acid oxidation at the CPT I step, increased t1/2 to 4.3 +/- 0.1 min (n=3), (p 11C] acetate and palmitate may allow dissection of the site of inhibition of fatty acid oxidation in vivo in normal and pathophysiological conditions

244

Estimation of glomerular filtration rate using chromium-51 ethylene diamine tetra-acetic acid and technetium-99m diethylene triamine penta-acetic acid  

Energy Technology Data Exchange (ETDEWEB)

Simultaneous measurements of the clearance rate of chromium-51 ethylene diamine tetra-acetic acid ({sup 51}Cr-EDTA) and technetium-99m diethylene triamine penta-acetic acid ({sup 99m}Tc-DTPA) were performed in 54 patients with a range of function between 9 and 176 ml/min. Using multiple blood samples the two clearance values correlated well (r = 0.97, SEE 8.6 ml/min) and DTPA clearance was higher by 2.9%. For each radiopharmaceutical the plasma clearance rates obtained using multiple blood samples were compared with those obtained with simplified methods, i.e., the 60-180 min two-sample method of Russell and the mono-exponential method with the Brochner-Mortensen correction. For both radiopharmaceuticals the clearance values correlated well with the Russell method (r = 0.99, SEE = 4.1 ml/min for EDTA; r = 0.99, SEE 4.9 ml/min for DTPA) and the mono-exponential method (r = 0.99, SEE 3.6 ml/min for EDTA; r = 0.99, SEE 3.9 ml/min for DTPA). The mean plasma clearance obtained using multiple blood samples did not differ significantly from that obtained with the Russell method, either in patients with a glomerular filtration rate (GFR)<30 ml/min or in patients with GFR{>=} 30 ml/min. The mean plasma clearance obtained using multiple blood samples differed significantly from that obtained with the mono-exponential method because of the great difference observed in patients with GFR{>=}30 ml/min. It is concluded that the Russell two-sample method after injection of {sup 99m}Tc-DTPA is accurate enough for routine clinical use. (orig.)

Biggi, A. [Dept. of Nuclear Medicine, S. Croce General Hospital, Cuneo (Italy); Viglietti, A. [Dept. of Nuclear Medicine, S. Croce General Hospital, Cuneo (Italy); Farinelli, M.C. [Dept. of Nuclear Medicine, S. Croce General Hospital, Cuneo (Italy); Bonada, C. [Dept. of Nuclear Medicine, S. Croce General Hospital, Cuneo (Italy); Camuzzini, G. [Dept. of Nuclear Medicine, S. Croce General Hospital, Cuneo (Italy)

1995-06-01

245

Mechanisms leading to oligomers and SOA through aqueous photooxidation: insights from OH radical oxidation of acetic acid  

Science.gov (United States)

Previous experiments have demonstrated that the aqueous OH radical oxidation of methylglyoxal produces low volatility products including oxalate and oligomers. These products are found predominantly in the particle phase in the atmosphere, suggesting that methylglyoxal is a precursor of secondary organic aerosol (SOA). Acetic acid is an important intermediate in aqueous methylglyoxal oxidation and a ubiquitous product of gas phase photochemistry, making it a potential "aqueous" SOA precursor in its own right. Altieri et al. (2008) proposed that acetic acid was the precursor of oligoesters observed in methylglyoxal oxidation. However, the fate of acetic acid upon aqueous-phase oxidation is not well understood. In this research, acetic acid at concentrations relevant to atmospheric waters (20 ?M-10 mM) was oxidized by OH radical. Products were analyzed by ion chromatography (IC), electrospray ionization mass spectrometry (ESI-MS), and IC-ESI-MS. The formation of glyoxylic, glycolic, and oxalic acids were observed. In contrast to methylglyoxal oxidation, succinic acid and oligomers were not detected. Using results from these and methylglyoxal + OH radical experiments, radical mechanisms responsible for oligomer formation from methylglyoxal oxidation in clouds and wet aerosols are proposed. The importance of acetic acid/acetate as an SOA precursor is also discussed. We hypothesize that this and similar chemistry is central to the daytime formation of oligomers in wet aerosols.

Tan, Y.; Lim, Y. B.; Altieri, K. E.; Seitzinger, S. P.; Turpin, B. J.

2011-06-01

246

Mechanisms leading to oligomers and SOA through aqueous photooxidation: insights from OH radical oxidation of acetic acid  

Directory of Open Access Journals (Sweden)

Full Text Available Previous experiments have demonstrated that the aqueous OH radical oxidation of methylglyoxal produces low volatility products including oxalate and oligomers. These products are found predominantly in the particle phase in the atmosphere, suggesting that methylglyoxal is a precursor of secondary organic aerosol (SOA. Acetic acid is an important intermediate in aqueous methylglyoxal oxidation and a ubiquitous product of gas phase photochemistry, making it a potential "aqueous" SOA precursor in its own right. Altieri et al. (2008 proposed that acetic acid was the precursor of oligoesters observed in methylglyoxal oxidation. However, the fate of acetic acid upon aqueous-phase oxidation is not well understood. In this research, acetic acid at concentrations relevant to atmospheric waters (20 ?M–10 mM was oxidized by OH radical. Products were analyzed by ion chromatography (IC, electrospray ionization mass spectrometry (ESI-MS, and IC-ESI-MS. The formation of glyoxylic, glycolic, and oxalic acids were observed. In contrast to methylglyoxal oxidation, succinic acid and oligomers were not detected. Using results from these and methylglyoxal + OH radical experiments, radical mechanisms responsible for oligomer formation from methylglyoxal oxidation in clouds and wet aerosols are proposed. The importance of acetic acid/acetate as an SOA precursor is also discussed. We hypothesize that this and similar chemistry is central to the daytime formation of oligomers in wet aerosols.

Y. Tan

2011-06-01

247

Sources and sinks of formic, acetic, and pyruvic acids over central Amazonia. II - Wet season  

Science.gov (United States)

Potential sources and sinks of formic, acetic, and pyruvic acids over the Amazon forest were investigated using a photochemical model and data collected on gas phase concentrations of these acids in the forest canopy, boundary layer, and free troposphere over the central Amazon Basin during the 1987 wet season. It was found that the atmospheric reactions previously suggested in the literature as sources of carboxylic acids (i.e., the gas phase decomposition of isoprene, the reaction between CH3CO3 and a peroxide, and aqueous phase oxidation of CH2O) appear to be too slow to explain the observed concentrations, suggesting that other atmospheric reactions, so far unidentified, could make a major contribution to the carboxylic acid budgets.

Talbot, R. W.; Andreae, M. O.; Berresheim, H.; Jacob, D. J.; Beecher, K. M.

1990-01-01

248

INHIBITION OF NEURAL CREST CELL MIGRATION BY THE WATER DISINFECTION BYPRODUCTS DICHLORO-, DIBROMO-, AND BROMOCHLORO-ACETIC ACID.  

Science.gov (United States)

INHIBITION OF NEURAL CREST CELL MIGRATION BY THE WATER DISINFECTION BYPRODUCTS DICHLORO-, DIBROMO- AND BROMOCHLORO-ACETIC ACID. JE Andrews, H Nichols, J Schmid 1, and ES Hunter. Reproductive Toxicology Division, 1Research Support Division, NHEERL, USEPA, RTP, NC, USA. ...

249

Isolation and characterization of indole acetic acid (IAA) producing bacteria from rhizospheric soil and its effect on plant growth  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english Indole acetic acid (IAA) production is a major property of rhizosphere bacteria that stimulate and facilitate plant growth. The present work deals with isolation, characterization and identification of indole acetic acid producing bacteria from the rhizospheric soil. Out of ten Indole acetic acid pr [...] oducing isolates, five were selected as efficient producers. Optimization of indole acetic acid production was carried out at different cultural conditions of pH and temperature with varying media components such as carbon and nitrogen source, tryptophan concentration. Partial purification of IAA was done and purity was confirmed with Thin layer chromatography. Subsequently, effect on plant growth was tested by pot assay. In conclusion the study suggests the IAA producing bacteria as efficient biofertilizer inoculants to promote plant growth.

B, Mohite.

250

Isolation and characterization of indole acetic acid (IAA) producing bacteria from rhizospheric soil and its effect on plant growth  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english Indole acetic acid (IAA) production is a major property of rhizosphere bacteria that stimulate and facilitate plant growth. The present work deals with isolation, characterization and identification of indole acetic acid producing bacteria from the rhizospheric soil. Out of ten Indole acetic acid pr [...] oducing isolates, five were selected as efficient producers. Optimization of indole acetic acid production was carried out at different cultural conditions of pH and temperature with varying media components such as carbon and nitrogen source, tryptophan concentration. Partial purification of IAA was done and purity was confirmed with Thin layer chromatography. Subsequently, effect on plant growth was tested by pot assay. In conclusion the study suggests the IAA producing bacteria as efficient biofertilizer inoculants to promote plant growth.

B, Mohite.

2013-09-01

251

Stiffening agent for cotton woven fabrics from (Methacrylic Acid/Vinyl Acetate/Methylacrylate) Terpolymer  

International Nuclear Information System (INIS)

The emulsion polymerizations of (Methacrylic acid-co-vinyl acetate co- methylacrylate) terpolymer in different vinyl acetate/methylacrylate molar ratios were carried out using sodium dodecyl sulphate (SDS) as emulsifier and K2S2O8 as initiator at 70 degree C for 6 hours in semicontinuous reaction mode. The molecular weights and the molecular weights distributions were determined using Gel permeation chromatography. All terpolymers prepared showed mono modal molecular weight polymdispersity indices around 4. Tg s and thermal stability of the prepared terpolymers were determined using DSC and TGA respectively. The elongation at rupture and tensile strength were determined as functions of the molar composition in the emulsion feed. The terpolymers prepared were tested as stiffening agents for the polyester and cotton woven fabrics. The effect of molar composition in the emulsion feed upon the stiffening efficiency was discussed

252

Radiolabeled acetate as a tracer of myocardial tricarboxylic acid cycle flux  

Energy Technology Data Exchange (ETDEWEB)

The kinetics of (1-14C)acetate oxidation in isolated perfused rat hearts have been determined over a range of perfusion conditions. Effluent measurements demonstrated that 14CO2 cleared biexponentially over 50 minutes after bolus injection of (1-14C)acetate into normoxic hearts perfused with 5 mM glucose and 10 mU/ml insulin. The clearance half-time (t1/2) for the predominant initial clearance phase was 3.1 +/- 0.5 minutes (n = 4). MVO2 was varied over a fourfold range by hypoxia and phenylephrine stimulation (t1/2, 7.2 +/- 1.2 and 2.2 +/- 0.2 minutes, respectively) and in the presence of alternate substrates (lactate, 2 mM; DL-3-hydroxybutyrate, 20 mM; and palmitate, 0.1 mM), which did not modify either tricarboxylic acid (TCA) cycle flux or acetate kinetics. A good correlation (r = 0.93) was observed between k, the rate constant for the initial phase of 14CO2 clearance, and TCA cycle flux, estimated from oxygen consumption. In contrast to results with (1-14C)acetate, lactate (2 mM) increased t1/2 for 14CO2 clearance from a bolus injection of (1-14C)palmitate from 3.0 +/- 0.4 minutes (n = 3) at control to 4.3 +/- 0.2 minutes (n = 3, p less than 0.01). Addition of acetate in nontracer amounts (0.5 or 5 mM) caused significant underestimation of TCA cycle flux when estimated with (1-14C)acetate. 14CO2 clearance accounted for 88-98% of total effluent 14C between 10 and 20 minutes after (1-14C)acetate bolus injection; rate constants for clearance of 14CO2 and total 14C clearance were very similar during this period, and these two rate constants did not differ significantly from each other under any conditions tested.

Buxton, D.B.; Schwaiger, M.; Nguyen, A.; Phelps, M.E.; Schelbert, H.R.

1988-09-01

253

Reactivity toward thiols and cytotoxicity of 3-methylene-2-oxindoles, cytotoxins from indole-3-acetic acids, on activation by peroxidases.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Oxidation of indole-3-acetic acid and its derivatives by peroxidases such as that from horseradish produces many products, including 3-methylene-2-oxindoles. These have long been associated with biological activity, but their reactivity has not been characterized. We have previously demonstrated the potential value of substituted indole acetic acids and horseradish peroxidase as the basis for targeted cancer therapy, since the compounds are of low cytotoxicity until oxidized, when high cytoto...

Folkes, Lk; Rossiter, S.; Wardman, P.

2002-01-01

254

An overview of acetic acid ulcer models--the history and state of the art of peptic ulcer research.  

Science.gov (United States)

Four types of experimental chronic ulcer models, named acetic acid ulcer models, have been developed to examine the healing process of peptic ulcers, screen anti-ulcer drugs, and better evaluate the adverse effects of various anti-inflammatory drugs on the gastrointestinal mucosa. The model easily and reliably produces round, deep ulcers in the stomach and duodenum, allowing acetic acid ulcer production in mice, rats, Mongolian gerbils, guinea pigs, cats, dogs, miniature pigs, and monkeys. These ulcer models highly resemble human ulcers in terms of both pathological features and healing process. The models have been established over the past 35 years and are now used throughout the world by basic and clinical scientists. One of the characteristic features of acetic acid ulcers in rats is the spontaneous relapse of healed ulcers >100 d after ulceration, an endoscopically confirmed phenomenon. Indomethacin significantly delays the healing of acetic acid ulcers, probably by reducing endogenous prostaglandins and inhibiting angiogenesis in ulcerated tissue. Helicobacter pylori significantly delays healing of acetic acid ulcers and causes relapse of healed ulcers at a high incidence in Mongolian gerbils. Anti-secretory drugs (e.g. omeprazole), prostaglandin analogs, mucosal defense agents (e.g. sucralfate), and various growth factors all significantly enhance healing of acetic acid ulcers. Gene therapy with epidermal growth factor and vascular endothelial growth factor applied to the base of acetic acid ulcers in rats is effective in enhancing ulcer healing. Since an inhibitor of nitric oxide syntase prevents ulcer healing, nitric oxide might be involved in the mechanism underlying ulcer healing. We conclude that acetic acid ulcer models are quite useful for various studies related to peptic ulcers. PMID:16079471

Okabe, Susumu; Amagase, Kikuko

2005-08-01

255

Mutants of the pentose-fermenting yeast Pachysolen tannophilus tolerant to hardwood spent sulfite liquor and acetic acid.  

Science.gov (United States)

A strain development program was initiated to improve the tolerance of the pentose-fermenting yeast Pachysolen tannophilus to inhibitors in lignocellulosic hydrolysates. Several rounds of UV mutagenesis followed by screening were used to select for mutants of P. tannophilus NRRL Y2460 with improved tolerance to hardwood spent sulfite liquor (HW SSL) and acetic acid in separate selection lines. The wild type (WT) strain grew in 50 % (v/v) HW SSL while third round HW SSL mutants (designated UHW301, UHW302 and UHW303) grew in 60 % (v/v) HW SSL, with two of these isolates (UHW302 and UHW303) being viable and growing, respectively, in 70 % (v/v) HW SSL. In defined liquid media containing acetic acid, the WT strain grew in 0.70 % (w/v) acetic acid, while third round acetic acid mutants (designated UAA301, UAA302 and UAA303) grew in 0.80 % (w/v) acetic acid, with one isolate (UAA302) growing in 0.90 % (w/v) acetic acid. Cross-tolerance of HW SSL-tolerant mutants to acetic acid and vice versa was observed with UHW303 able to grow in 0.90 % (w/v) acetic acid and UAA302 growing in 60 % (v/v) HW SSL. The UV-induced mutants retained the ability to ferment glucose and xylose to ethanol in defined media. These mutants of P. tannophilus are of considerable interest for bioconversion of the sugars in lignocellulosic hydrolysates to ethanol. PMID:24122119

Harner, Nicole K; Bajwa, Paramjit K; Habash, Marc B; Trevors, Jack T; Austin, Glen D; Lee, Hung

2014-01-01

256

Adsorptive removal of fermentation inhibitors from concentrated acid hydrolyzates of lignocellulosic biomass.  

Science.gov (United States)

Adsorptive purification of concentrated acid hydrolyzate of lignocellulose was investigated. Cation exchange resin (CS16GC), neutral polymer adsorbent (XAD-16), and granulated activated carbon (GAC) were studied to remove furfural, HMF, and acetic acid from a synthetic hydrolyzate containing 20 wt.% H(2)SO(4). Adsorption isotherms were determined experimentally. Loading and regeneration were investigated in a laboratory scale column. GAC has the highest adsorption capacity, but regeneration with water was not feasible. XAD-16 and CS16GC had lower adsorption capacities but also shorter cycle times due to easier regeneration. Productivity increased when regenerating with 50 wt.% EtOH(aq) solution. To compare adsorbents, process performance was quantified by productivity and fraction of inhibitors removed. GAC yields highest performance when high purity is required and ethanol can be used in regeneration. For lower purities, XAD-16 and GAC yield approximately equal performance. When using ethanol must be avoided, CS16GC offers highest productivity. PMID:21441022

Sainio, Tuomo; Turku, Irina; Heinonen, Jari

2011-05-01

257

CTAB and acetic acid effect in the nanocrystallite growth of spray deposited CdO thin films  

Science.gov (United States)

CdO thin films were deposited on glass substrates from cadmium acetate dihydrate along with precursor additives, acetic acid and CTAB using home built splay pyrolysis unit. XRD studies imply that the CdO thin films to be preferably oriented in the (1 1 1) plane. The Williamson-Hall plot indicates the presence of microstrain, especially high with acetic acid additive. Surface morphology was found to be closely packed spherical crystallite with precursor additives. Optical studies reveal a considerable change in the transmittance and band gap. Peak position is shifted in the Raman spectra, due to precursor additives.

Pavithra, S.; Balamurugan, D.; Pandeeswari, R.; Jeyaprakash, B. G.

2014-11-01

258

Different response to acetic acid stress in Saccharomyces cerevisiae wild-type and l-ascorbic acid-producing strains.  

Science.gov (United States)

Biotechnological processes are of increasing significance for industrial production of fine and bulk chemicals, including biofuels. Unfortunately, under operative conditions microorganisms meet multiple stresses, such as non-optimal pH, temperature, oxygenation and osmotic stress. Moreover, they have to face inhibitory compounds released during the pretreatment of lignocellulosic biomasses, which constitute the preferential substrate for second-generation processes. Inhibitors include furan derivatives, phenolic compounds and weak organic acids, among which acetic acid is one of the most abundant and detrimental for cells. They impair cellular metabolism and growth, reducing the productivity of the process: therefore, the development of robust cell factories with improved production rates and resistance is of crucial importance. Here we show that a yeast strain engineered to endogenously produce vitamin C exhibits an increased tolerance compared to the parental strain when exposed to acetic acid at moderately toxic concentrations, measured as viability on plates. Starting from this evidence, we investigated more deeply: (a) the nature and levels of reactive oxygen species (ROS); (b) the activation of enzymes that act directly as detoxifiers of reactive oxygen species, such as superoxide dismutase (SOD) and catalase, in parental and engineered strains during acetic acid stress. The data indicate that the engineered strain can better recover from stress by limiting ROS accumulation, independently from SOD activation. The engineered yeast can be proposed as a model for further investigating direct and indirect mechanism(s) by which an antioxidant can rescue cells from organic acid damage; moreover, these studies will possibly provide additional targets for further strain improvements. PMID:23847041

Martani, Francesca; Fossati, Tiziana; Posteri, Riccardo; Signori, Lorenzo; Porro, Danilo; Branduardi, Paola

2013-09-01

259

Synthesis and evaluation of mutual azo prodrug of 5-aminosalicylic acid linked to 2-phenylbenzoxazole-2-yl-5-acetic acid in ulcerative colitis  

Directory of Open Access Journals (Sweden)

Full Text Available Jamal A Jilani,1 Maha Shomaf,2 Karem H Alzoubi3 1Department of Medicinal Chemistry and Pharmacognosy, Jordan University of Science and Technology, Irbid, Jordan; 2Department of Pathology, Jordan University, Amman, Jordan; 3Department of Clinical Pharmacy, Jordan University of Science and Technology, Irbid, Jordan Abstract: In this study, the syntheses of 4-aminophenylbenzoxazol-2-yl-5-acetic acid, (an analogue of a known nonsteroidal anti-inflammatory drug [NSAID] and 5-[4-(benzoxazol-2-yl-5-acetic acidphenylazo]-2-hydroxybenzoic acid (a novel mutual azo prodrug of 5-aminosalicylic acid [5-ASA] are reported. The structures of the synthesized compounds were confirmed using infrared (IR, hydrogen-1 nuclear magnetic resonance (1H NMR, and mass spectrometry (MS spectroscopy. Incubation of the azo compound with rat cecal contents demonstrated the susceptibility of the prepared azo prodrug to bacterial azoreductase enzyme. The azo compound and the 4-aminophenylbenzoxazol-2-yl-5-acetic acid were evaluated for inflammatory bowel diseases, in trinitrobenzenesulfonic acid (TNB-induced colitis in rats. The synthesized diazo compound and the 4-aminophenylbenzoxazol-2-yl-5-acetic acid were found to be as effective as 5-aminosalicylic acid for ulcerative colitis. The results of this work suggest that the 4-aminophenylbenzoxazol-2-yl-5-acetic acid may represent a new lead for treatment of ulcerative colitis. Keywords: benzoxazole acetic acid, azo prodrug, colon drug delivery

Jilani JA

2013-07-01

260

Effects of trimetazidine in ethanol- and acetic acid-induced colitis: oxidant/anti-oxidant status.  

Science.gov (United States)

There is overwhelming evidence in favour of a significant role of reactive oxygen metabolites (ROM) in the pathophysiology of inflammatory bowel disease (IBD) in man and in experimental animal models. This study was undertaken to investigate the possible protective effects of pretreatment with trimetazidine (TMZ) on the oxidant-anti-oxidant balance in ethanol- and acetic acid-induced colonic damage in rats. TMZ was chosen because of its various cytoprotective features (preserving cellular ATP levels, limiting intracellular acidosis and limiting inorganic phosphate, Na(+) and Ca(2+) accumulation) and anti-oxy characteristics which were previously reported. A total of 80 rats were randomized into eight major groups each consisting of 10 animals. Animals in groups 1, 2 and 3 served as models of ethanol-induced colitis (0.25?ml of 30% (v/v) ethanol), while group 4 served as their control. Animals in groups 5, 6 and 7 served as models of acetic acid-induced colitis (1?ml of 4% (v/v) acetic acid), while group 8 served as their control. TMZ was administered 5?mg/kg by intrarectal (i.r.) and intraperitoneal (i.p.) routes to groups 1, 2, 5 and 6. Intraperitoneal administration of TMZ was used in order to evaluate its systemic effect while i.r. administration was used to determine its local effect. After decapitation, colon mucosa samples were obtained and evaluated macroscopically and microscopically. Myeloperoxidase (MPO) activities as markers for inflammation, malondialdehyde (MDA) levels as markers for oxidant stress and reduced glutathione (GSH) and oxidized glutathione (GSSG) levels as markers for anti-oxidant status were determined. Acute colitis was observed in macroscopic and microscopic evaluation in ethanol- and acetic acid-administered groups compared with controls (P?=?0.000). The macroscopic and microscopic scores in colitis groups were correlated with MPO activities (r?=?0.5365, P?=?0.000 and r?=?0.5499, P?=?0.000, respectively). MDA and GSSG levels in the acetic acid-induced colitis group were higher compared with ethanol-induced colitis group (P?models are appropriate experimental colitis models which in many ways manifest the characteristics seen in tissue injury related to colitis in humans. Of these two, the acetic acid-induced colitis model proved more suitable than the ethanol model for investigating the alterations in long-term and in more severe tissue injury. While TMZ pretreatment via i.p. or i.r. route did not improve the oxidative-inflammative state in either of these models, it did contribute significantly to the preservation of the anti-oxidant pool via the conservation of intracellular GSH levels. This conserving effect of TMZ was substantially more pronounced in the i.p. route compared with the i.r. route. Based on our results, we conclude that the 'GSH-preservation' role of TMZ can be the mode of action it manifests as an anti-oxy compound. PMID:23574598

Girgin; Karaoglu; Tüzün; Erkus; Ozütemiz; Dinçer; Batur; Tanyalçin

1999-11-01

 
 
 
 
261

Simultaneous determination of 2-naphthoxyacetic acid and indole-3-acetic acid by first derivation synchronous fluorescence spectroscopy  

Science.gov (United States)

A simple, rapid, sensitive and selective method for simultaneously determining 2-naphthoxyacetic acid (BNOA) and Indole-3-Acetic Acid (IAA) in mixtures has been developed using derivation synchronous fluorescence spectroscopy based on their synchronous fluorescence. The synchronous fluorescence spectra were obtained with ?? = 100 nm in a pH 8.5 NaH2PO4-NaOH buffer solution, and the detected wavelengths of quantitative analysis were set at 239 nm for BNOA and 293 nm for IAA respectively. The over lapped fluorescence spectra were well separated by the synchronous derivative method. Under optimized conditions, the limits of detection (LOD) were 0.003 ?g/mL for BNOA and 0.012 ?g/mL for IAA. This method is simple and expeditious, and it has been successfully applied to the determination of 2-naphthoxyacetic acid and indole-3-acetic acid in fruit juice samples with satisfactory results. The samples were only filtrated through a 0.45 ?m membrane filter, which was free from the tedious separation procedures. The obtaining recoveries were in the range of 83.88-87.43% for BNOA and 80.76-86.68% for IAA, and the relative standard deviations were all less than 5.0%. Statistical comparison of the results with high performance liquid chromatography Mass Spectrometry (HPLC-MS) method revealed good agreement and proved that there were no significant difference in the accuracy and precision between these two methods.

Liu, Xiangxiang; Wan, Yiqun

2013-07-01

262

Acetalization of hexanal with 2-ethyl hexanol catalyzed by solid acids  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A atividade catalítica de sólidos ácidos como o fosfato de nióbio e a Amberlyst 35, uma resina trocadora de íons, foi avaliada na acetalização do hexanal com 2-etil-hexanol. Foram avaliadas a concentração do catalisador e a temperatura de reação na conversão do hexanal. A possibilidade de re-utiliza [...] ção do fosfato de nióbio também foi estudada e evidenciou ser possível re-utilizar este catalisador sem perda da atividade. O rendimento em acetal foi acima de 90% em condições brandas de reação. Abstract in english The catalyst activity of solid acids such as niobium phosphate and Amberlyst 35, an ion exchange resin, was evaluated in the acetalization of hexanal with 2-ethyl-hexanol. The catalyst loading and the reaction temperature were evaluated in the hexanal conversions. The possibility of recycling niobiu [...] m phosphate was also studied, showing that it was possible to reuse this catalyst without significant loss in its catalytic activity. The yield in acetal was above 90% under mild conditions.

Alessandro O, Barros; Aline T, Faísca; Elizabeth R, Lachter; Regina S. V, Nascimento; Rosane A. S, San Gil.

263

Sequential study on Reactive Blue 29 Dye Removal from Aqueous Solution by Peroxy Acid and Single Wall Carbon Nanotubes: Experiment and Theory  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The majority of anthraquinone dye released to the environment come from antrapogenic sources. Several techniques are available for dyes' removal. In this study removal of reactive blue 29 (RB29) by an advanced oxidation process sequenced with single wall carbon nanotubes was investigated. Advanced oxidation process wasoptimized over a period of 60 minutes by changing the ratio of acetic acid to hydrogen peroxide, the compounds which form peroxy acid. Reduction of 20.2% -56.4% of reactive blue...

Mahsa Jahangiri-Rad; Kazem Nadafi; Alireza Mesdaghinia; Ramin Nabizadeh; Masood Younesian; Mohammad Rafiee

2012-01-01

264

Sequential study on reactive blue 29 dye removal from aqueous solution by peroxy acid and single wall carbon nanotubes: experiment and theory  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract The majority of anthraquinone dye released to the environment come from antrapogenic sources. Several techniques are available for dyes' removal. In this study removal of reactive blue 29 (RB29) by an advanced oxidation process sequenced with single wall carbon nanotubes was investigated. Advanced oxidation process was optimized over a period of 60 minutes by changing the ratio of acetic acid to hydrogen peroxide, the compounds which form peroxy acid. Reduction of 20.2% -56...

Jahangiri-Rad Mahsa; Nadafi Kazem; Mesdaghinia Alireza; Nabizadeh Ramin; Younesian Masood; Rafiee Mohammad

2013-01-01

265

Hydroxylamine hydrochloride-acetic acid-soluble and -insoluble fractions of pelagic sediment: Readsorption revisited  

Science.gov (United States)

The extraction of the rare earth elements (REE) from deep-ocean pelagic sediment, using hydroxylamine hydrochloride-acetic acid, leads to the separation of approximately 70% of the bulk REE content into the soluble fraction and 30% into the insoluble fraction. The REE pattern of the soluble fraction, i.e., the content of REE normalized to average shale on an element-by-element basis and plotted against atomic number, resembles the pattern for seawater, whereas the pattern, as well as the absolute concentrations, in the insoluble fraction resembles the North American shale composite. These results preclude significant readsorption of the REE by the insoluble phases during the leaching procedure.

Piper, D. Z.; Wandless, G. A.

1992-01-01

266

Determination of iodide ions in commercial acetic acid using catalymetric method  

International Nuclear Information System (INIS)

A simple and reliable express method of determining iodide ions in commercial acetic acid being part of methanol carbonylation catalyst is suggested. The method is based on reaction of rhodanide-ion oxidation by iron(3) ions in the presence of nitrite-ions. The reaction rate depends on concentration of reaction catalyst-iodide ions, that is used for their quantitative determination. The absorption difference that is directly proportional to catalyst concentration under constant ?t is measured within a definite interval (?t) by spectrophotometric method. The confidence level being P=0.95, the sum error relative value is 14.3%

267

Plasma polymerized allylamine coated quartz particles for humic acid removal.  

Science.gov (United States)

Allylamine plasma polymerization has been used to modify the surface of quartz particles for humic acid removal via an inductively coupled rotating barrel plasma reactor. Plasma polymerized allylamine (ppAA) films were deposited at a power of 25 W, allylamine flow rate of 4.4 sccm and polymerization times of 5-60 min. The influence of polymerization time on surface chemistry was investigated via X-ray photoelectron spectroscopy (XPS), time of flight secondary ion mass spectrometry (ToF-SIMS) and electrokinetic analysis. Acid orange 7 adsorption/desorption quantified the number of surface amine groups. Humic acid removal via ppAA quartz particles was examined by varying pH, removal time, humic acid concentration, and particle mass. Increasing the polymerization time increased the concentration of amine groups on the ppAA quartz surface, thus also increasing the isoelectric point. ToF-SIMS demonstrated uniform distribution of amine groups across the particle surface. Greatest humic acid removal was observed at pH 5 due to electrostatic attraction. At higher pH values, for longer polymerization times, humic acid removal was also observed due to hydrogen bonding. Increasing the initial humic acid concentration increased the mass of humic acid removed, with longer polymerization times exhibiting the greatest increases. Plasma polymerization using a rotating plasma reactor has shown to be a successful method for modifying quartz particles for the removal of humic acid. Further development of the plasma polymerization process and investigation of additional contaminants will aid in the development of a low cost water treatment system. PMID:22633110

Jarvis, Karyn L; Majewski, Peter

2012-08-15

268

Liquid phase equilibria of (water + phosphoric acid + 1-butanol or butyl acetate) ternary systems at T = 308.2 K  

International Nuclear Information System (INIS)

(Liquid + liquid) equilibria and tie lines for the ternary systems of (water + phosphoric acid + 1-butanol) and (water + phosphoric acid + butyl acetate) were measured at T = 308.2 K. The experimental ternary (liquid + liquid) equilibrium data were correlated with the UNIQUAC model. The reliability of the experimental tie lines was confirmed using Othmer-Tobias correlation. The average root-mean-square deviation (RMSD) values of (water + phosphoric acid + 1-butanol) and (water + phosphoric acid + butyl acetate) systems were 2.17% and 2.16%, respectively. Distribution coefficients and separation factors were measured to evaluate the extracting capability of the solvents. The results show that butyl acetate may be considered as a reliable organic solvent for the extraction of phosphoric acid from aqueous solutions

269

Gluconacetobacter maltaceti sp. nov., a novel vinegar producing acetic acid bacterium.  

Science.gov (United States)

Comparison of HaeIII- and HpaII-restriction profiles of PCR-amplified 16S-23S rDNA ITS regions of Gluconacetobacter sp. LMG 1529(T) and SKU 1109 with restriction profiles of reference strains of acetic acid bacteria described by Tr?ek and Teuber [34] revealed the same but unique restriction profiles for LMG 1529(T) and SKU 1109. Further analyses of nearly complete 16S rRNA gene sequences, nearly complete 16S-23S rDNA ITS sequences, as well as concatenated partial sequences of the housekeeping genes dnaK, groEL and rpoB, allocated both strains to a single phylogenetic cluster well separated from the other species of the genus Gluconacetobacter. DNA-DNA hybridizations confirmed their novel species identity by 73% DNA-DNA relatedness between both strains, and values below the species level (Gluconacetobacter species, Gluconacetobacter entanii and Gluconacetobacter hansenii, by their ability to form 2-keto-d-gluconic acid from d-glucose, their ability to use d-mannitol, d-gluconate and glycerol as carbon source and form acid from d-fructose, and their ability to grow without acetic acid. The major fatty acid of LMG 1529(T) and SKU 1109 is C(18:1?7c) (60.2-64.8%). The DNA G+C content of LMG 1529(T) and SKU 1109 is 62.5 and 63.3mol% respectively. The name Gluconacetobacter maltaceti sp. nov. is proposed. The type strain is LMG 1529(T) (=NBRC 14815(T)=NCIMB 8752(T)). PMID:23273842

Slapšak, Nina; Cleenwerck, Ilse; De Vos, Paul; Tr?ek, Janja

2013-02-01

270

Polyacrylonitrile/manganese acetate composite nanofibers and their catalysis performance on chromium (VI) reduction by oxalic acid  

International Nuclear Information System (INIS)

Highlights: ? We have successfully prepared PAN/Mn(CH3COO)2 composite nanofibers. ? The nanofibers exhibit excellent catalysis performance for Cr(VI) reduction. ? The nanofibers are effective and environment-friendly materials to remove Cr(VI). - Abstract: Polyacrylonitrile(PAN)/manganese acetate(Mn(CH3COO)2) composite nanofibers have been fabricated by electrospinning, a simple and effective technology. The obtained composite nanofibers were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectrometer (FT-IR). The composite nanofibers are amorphous in structure, continuous, even and smooth. At the same time, the reduction performance of Cr(VI) by oxalic acid in the presence of the composite nanofibers is also investigated. The results indicate that the composite nanofibers have exhibited excellent catalysis performance for Cr(VI) reduction from a Cr2O72?-containing solution by oxalic acid. And the critical parameters, such as the catalyst dosage, oxalic acid content, chromium concentration, the pH value of the reaction solution and light have important impact on the reduction process. Under the simulated solar light irradiation, after only 60 min, 1.2 mM initial Cr(VI) solution was reduced absolutely in the presence of PAN/Mn(CH3COO)2 composite nanofibers containing 17.5 wt.% Mn(CH3COO)25 wt.% Mn(CH3COO)2 by 0.3 mL 0.5 M oxalic acid. In light, the reduction of Cr(VI) by oxalic acid is markedly accelerated.

271

Polyacrylonitrile/manganese acetate composite nanofibers and their catalysis performance on chromium (VI) reduction by oxalic acid  

Energy Technology Data Exchange (ETDEWEB)

Highlights: Black-Right-Pointing-Pointer We have successfully prepared PAN/Mn(CH{sub 3}COO){sub 2} composite nanofibers. Black-Right-Pointing-Pointer The nanofibers exhibit excellent catalysis performance for Cr(VI) reduction. Black-Right-Pointing-Pointer The nanofibers are effective and environment-friendly materials to remove Cr(VI). - Abstract: Polyacrylonitrile(PAN)/manganese acetate(Mn(CH{sub 3}COO){sub 2}) composite nanofibers have been fabricated by electrospinning, a simple and effective technology. The obtained composite nanofibers were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectrometer (FT-IR). The composite nanofibers are amorphous in structure, continuous, even and smooth. At the same time, the reduction performance of Cr(VI) by oxalic acid in the presence of the composite nanofibers is also investigated. The results indicate that the composite nanofibers have exhibited excellent catalysis performance for Cr(VI) reduction from a Cr{sub 2}O{sub 7}{sup 2-}-containing solution by oxalic acid. And the critical parameters, such as the catalyst dosage, oxalic acid content, chromium concentration, the pH value of the reaction solution and light have important impact on the reduction process. Under the simulated solar light irradiation, after only 60 min, 1.2 mM initial Cr(VI) solution was reduced absolutely in the presence of PAN/Mn(CH{sub 3}COO){sub 2} composite nanofibers containing 17.5 wt.% Mn(CH{sub 3}COO){sub 2} by 0.3 mL 0.5 M oxalic acid. In light, the reduction of Cr(VI) by oxalic acid is markedly accelerated.

Zhang, Chengcheng [Jilin University Alan G MacDiarmid Institute, Changchun 130012 (China); Li, Xiang, E-mail: xiangli@jlu.edu.cn [Jilin University Alan G MacDiarmid Institute, Changchun 130012 (China); Bian, Xiujie; Zheng, Tian [Jilin University Alan G MacDiarmid Institute, Changchun 130012 (China); Wang, Ce, E-mail: cwang@jlu.edu.cn [Jilin University Alan G MacDiarmid Institute, Changchun 130012 (China)

2012-08-30

272

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

Directory of Open Access Journals (Sweden)

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.

Bhaskar D. Kulkarni

2014-01-01

273

Suspended biofilm carrier and activated sludge removal of acidic pharmaceuticals  

DEFF Research Database (Denmark)

Removal of seven active pharmaceutical substances (ibuprofen, ketoprofen, naproxen, diclofenac, clofibric acid, mefenamic acid, and gemfibrozil) was assessed by batch experiments, with suspended biofilm carriers and activated sludge from several full-scale wastewater treatment plants. A distinct difference between nitrifying activated sludge and suspended biofilm carrier removal of several pharmaceuticals was demonstrated. Biofilm carriers from full-scale nitrifying wastewater treatment plants, demonstrated considerably higher removal rates per unit biomass (i.e. suspended solids for the sludges and attached solids for the carriers) of diclofenac, ketoprofen, gemfibrozil, clofibric acid and mefenamic acid compared to the sludges. Among the target pharmaceuticals, only ibuprofen and naproxen showed similar removal rates per unit biomass for the sludges and biofilm carriers. In contrast to pharmaceutical removal, the nitrification capacity per unit biomass was lower for the carriers than the sludges, which suggests that neither the nitrite nor the ammonia oxidizing bacteria are primarily responsible for the observed differences in pharmaceutical removal. The low ability of ammonia oxidizing bacteria to degrade or transform the target pharmaceuticals was further demonstrated by the limited pharmaceutical removal in an experiment with continuous nitritation and biofilm carriers from a partial nitritation/anammox sludge liquor treatment process.

Andersen, Henrik Rasmus

2012-01-01

274

Formation of lateral homogeneous stain etched porous silicon with acetic acid at oxidant insufficiency  

International Nuclear Information System (INIS)

Full text : The influence of acetic acid on the process of stain etched porous silicon formation on the restricted surface area in etching solution HF/HNO3/CH3COOH at oxidant insufficiency have been investigated. It is shown, that with increasing of acetic acid concentration the incubation time increases, the rate of reaction falls, the evolution of bubbles decreases and the lateral homogeneity of stain etched porous silicon improves. It is found, that the process of stain etched porous silicon formation is accompanied with the evolution of two types of bubbles, which differ in their sizes, surface distribution and ability to stick to surface. The optimal concentration of etching solution, in which reaction occurs without bubbles evolution, is determined and very homogeneous, uniformly coloured specular porous silicon layers are obtained. In spite of the fact that the etching was performed on the restricted area of wafers surface the influence of boundaries did not occur and the pore formation process has a very good repeatability and reproducibility. It is shown that in this etchant composition the porous silicon formation does not depend on of etching solution. It is also shown, that the method of final treatment of the wafers surface before etching without changing the pore formation rate essentially affects the incubation time. The investigations of photoluminescence emission and excitation spectra showed that in spite of independence of photowed that in spite of independence of photoluminescence maximum position, optical bandgap of porous silicon decreases with increasing etching time

275

Protective effect of Copaifera langsdorffii oleo-resin against acetic acid-induced colitis in rats.  

Science.gov (United States)

The oleo-resin from Copaifera langsdorffii (Leguminosae) was evaluated in rats on acetic acid-induced colitis. Rats were pretreated orally (15 and 2 h) or rectally (2 h) before the induction of colitis with copaiba oleo-resin (200 and 400 mg/kg) or vehicle (1 ml, 2% Tween 80). Colitis was induced by intracolonic instillation of a 2 ml of 4% (v/v) acetic acid solution and 24 h later, the colonic mucosal damage was analyzed for the severity of macroscopic colonic damage, myeloperoxidase (MPO) activity, and malondialdehyde levels. A significant reduction in gross damage score and in wet weight/length ratio of colonic tissue were evident in test substance-pretreated animals as compared to vehicle or oleo-resin alone-treated controls. This effect was confirmed biochemically by a reduction in colonic myeloperoxidase activity, the marker of neutrophilic infiltration, and by a marked decrease in malondialdehyde level, an indicator of lipoperoxidation. Furthermore, microscopical examination revealed the diminution of inflammatory cell infiltration, and submucosal edema in the colon segments of rats treated with copaiba oleo-resin. The data indicate the protective effect of copaiba oleo-resin in the animal model of acute colitis possibly through an antioxidant and or anti-lipoperoxidative mechanism. PMID:15182904

Paiva, L A F; Gurgel, L A; De Sousa, E T; Silveira, E R; Silva, R M; Santos, F A; Rao, V S N

2004-07-01

276

Pickled egg production: effect of brine acetic acid concentration and packing conditions on acidification rate.  

Science.gov (United States)

U.S. federal regulations require that acidified foods must reach a pH of 4.6 or lower within 24 h of packaging or be kept refrigerated until then. Processes and formulations should be designed to satisfy this requirement, unless proper studies demonstrate the safety of other conditions. Our objective was to determine the effect of brine acetic acid concentration and packing conditions on the acidification rate of hard-boiled eggs. Eggs were acidified (60/40 egg-to-brine ratio) at various conditions of brine temperature, heat treatment to filled jars, and postpacking temperature: (i) 25 °C/none/25 °C (cold fill), (ii) 25 °C/none/2 °C (cold fill/refrigerated), (iii) 85 °C/none/25 °C (hot fill), and (iv) 25 °C/100 °C for 16 min/25 °C (water bath). Three brine concentrations were evaluated (7.5, 4.9, and 2.5% acetic acid) and egg pH values (whole, yolk, four points within egg) were measured from 4 to 144 h, with eggs equilibrating at pH 3.8, 4.0, and 4.3, respectively. Experiments were conducted in triplicate, and effects were considered significant when P eggs. PMID:24780334

Acosta, Oscar; Gao, Xiaofan; Sullivan, Elizabeth K; Padilla-Zakour, Olga I

2014-05-01

277

Agreement Between Visual Inspection with Acetic Acid and Papanicolaous Smear as Screening Methods for Cervical Cancer  

International Nuclear Information System (INIS)

Objective: To determine degree of agreement between visual inspection with acetic acid (VIA) and Papanicolaous (Pap) smear as screening methods for cervical cancer. Study Design: A cross-sectional study. Place and Duration of Study: Department of Obstetrics and Gynaecology, Sir Ganga Ram Hospital, Lahore, from July to December 2012. Methodology: Two hundred and fifty women in reproductive age group presenting with various gynaecological complaints were included in the study. A Papanicolaous smear was taken and visual inspection with 5% acetic acid was done. VIA was reported as positive or negative according to acetowhite changes and cytology result was graded as CIN 1, 2, 3 and squamous carcinoma. Those women who showed positive result with either VIA or Pap smear or both were further subjected to colposcopic directed biopsy which was taken as gold standard. Results were computed using Statistical Package for Social Sciences (SPSS) version 16 and statistical test used was kappa. Results: Out of 250 women, VIA was positive in 55 (22%) patients and Pap smear was abnormal in 27 (10.8%). Histological diagnosis of CIN/cancer was made in 36 out of a total 62 patients who underwent biopsy. Conclusion: There was a fair agreement between VIA and Pap smear, with VIA detecting more abnormalities than cytology. In the absence of Pap smear availability, VIA may be a reasonable cervical cancer screening method, especially in low resource settings. (author)

278

Protective effect of Dillenia indica L. on acetic acid induced colitis in mice.  

Science.gov (United States)

The inflammatory bowel disease (IBD) is an idiopathic, immune mediated and chronic inflammation of the intestine. The study aimed to elucidate the ameliorative effect of methanolic extract of Dillenia indica (DIME), hexane fraction (HFDI) and chloroform fraction (CFDI) of Dillenia indica in acetic acid induced experimental colitis in mice. Macroscopic score, colon weight, colonic catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), myeloperoxidase (MPO), malondialdehyde (MDA), tumor necrosis factor (TNF-alpha), and histological changes were recorded after the treatment regimen of 7 days. Intra-rectal instillation of acetic acid caused enhanced macroscopic score, colon weight, colonic MPO, MDA, and TNF-alpha level. It caused significant decreased level of CAT, SOD and GSH. DIME (800 mg/kg), HFDI (200 mg/kg) and CFDI (200 mg/kg) treatment exhibited significant effect in lowering macroscopic score, colon weight, MPO, MDA, TNF-alpha levels and elevation of CAT, GSH and SOD levels. The results suggest that D. indica has ameliorating effects on experimental colitis by inhibiting the proinflammatory mediators like TNF-alpha production. PMID:25241587

Somani, S J; Badgujar, L B; Sutariya, B K; Saraf, M N

2014-09-01

279

Azithromycin and erythromycin ameliorate the extent of colonic damage induced by acetic acid in rats  

International Nuclear Information System (INIS)

Ulcerative colitis is a common inflammatory bowel disease (IBD) of unknown etiology. Recent studies have revealed the role of some microorganisms in the initiation and perpetuation of IBD. The role of antibiotics in the possible modulation of colon inflammation is still uncertain. In this study, we evaluated the effects of two macrolides, namely azithromycin and erythromycin, at different doses on the extent and severity of ulcerative colitis caused by intracolonic administration of 3% acetic acid in rats. The lesions and the inflammatory response were assessed by histology and measurement of myeloperoxidase (MPO) activity, nitric oxide synthetase (NOS) and tumor necrosis factor alpha (TNF?) in colonic tissues. Inflammation following acetic acid instillation was characterized by oedema, diffuse inflammatory cell infiltration and necrosis. Increase in MPO, NOS and TNF? was detected in the colonic tissues. Administration of either azithromycin or erythromycin at different dosage (10, 20 and 40 mg/kg orally, daily for 5 consecutive days) significantly (P < 0.05) reduced the colonic damage, MPO and NOS activities as well as TNF? level. This reduction was highly significant with azithromycin when given at a dose of 40 mg/kg. It is concluded that azithromycin and erythromycin may have a beneficial therapeutic role in ulcerative colitis

280

Toward targeted 'oxidation therapy' of cancer: peroxidase-catalysed cytotoxicity of indole-3-acetic acids  

International Nuclear Information System (INIS)

Purpose: The study aimed to identify suitable prodrugs that could be used to test the hypothesis that peroxidase activity in cells, either endogenous or enhanced by immunological targeting, can activate prodrugs to cytotoxins. We hypothesized that prototype prodrugs based on derivatives of indole-3-acetic acid (IAA), when activated by peroxidase enzymes (e.g., from horseradish, HRP) should produce peroxyl radicals, with deleterious biological consequences. Methods and Materials: V79 hamster cells were incubated with IAA or derivatives ± HRP and cytotoxicity assessed by a clonogenic assay. To assess the toxicity of stable oxidation products, prodrugs were also oxidized by HRP without cells, and the products then added to cells. Results: The combination of prodrug and enzyme resulted in cytotoxicity, but neither indole nor enzyme in isolation was toxic under the conditions used. Although lipid peroxidation was stimulated in liposomes by the prodrug/enzyme treatment, it could not be measured in mammalian cells. Adding oxidized prodrugs to cells resulted in cytotoxicity. Conclusions: Although the hypothesis that prodrugs of this type could enhance oxidative stress via lipid peroxidation was not established, the results nonetheless demonstrated oxidatively-activated cytotoxicity via indole acetic acid prodrugs, and suggested these as a new type of substrate for antibody-directed enzyme-prodrug therapy (ADEPT). The hypothesized free-radical fragmentation intermediates were demonstrated, but lipid peroxidation associated with peroxyl radical formation was unlikely to be the major route to cytotoxicity

 
 
 
 
281

SYNTHESIS OF 2-METHYL4QUINOLONE-3-ACETIC ACIDS WITH POTENTIAL ANTIBACTERIAL ACTIVITY  

Directory of Open Access Journals (Sweden)

Full Text Available A number of quinolone-3-acetic acids were synthesized by cyclocondensation of substituted anilines with diethyl acetylsuccinate in the presence of phosphorous pentoxide and followed by base hydrolysis of the resultant esters to form respective acids. All synthesized compounds were found to exhibit antibacterial activities against a range of gram-positive (Bacillus subtilis, Staphylococcus aureus and gram-negative bacteria (Shigella sonnei, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi by broth dilution method. All the compounds exhibited antibacterial activities comparable to fluoroquinolones and in some cases even better activity was found. These findings suggest a great potential of these compounds for screening and use as antibacterial compounds for further studies with a battery of bacteria.

Fauzia Anjum Chattha

2012-01-01

282

An intercomparison of measurement systems for vapor and particulate phase concentrations of formic and acetic acids  

Science.gov (United States)

During June 1986, eight systems for measuring vapor phase and four for measuring particulate phase concentrations of formic acid (HCOOH) and acetic acid (CH3COOH) were intercompared in central Virginia. HCOOH and CH3COOH vapors were sampled by condensate, mist, Chromosorb 103 GC resin, NaOH-coated annular denuders, NaOH-impregnated quartz filters, K2CO3 and NaCO3-impregnated cellulose filters, and Nylasorb membranes. Atmospheric aerosol was collected on Teflon and Nuclepore filters using both hi-vol and lo-vol systems to measure particulate phase concentrations. Performances of the mist chamber and K2CO3-impregnated filter techniques were evaluated using zero air and ambient air spiked with HCOOH(g) and CH3COOH(g), and formaldehyde from permeation sources. The advantages and drawbacks of these methods are reported and discussed.

Keene, William C.; Talbot, Robert W.; Andreae, Meinrat O.; Beecher, Kristene; Berresheim, Harold

1989-01-01

283

A novel kinetic model for polysaccharide dissolution during atmospheric acetic acid pretreatment of sugarcane bagasse.  

Science.gov (United States)

Acetic acid (AcH) pretreatment of sugarcane bagasse with the catalysis of sulfuric acid (SA) could greatly enhance the enzymatic digestibility of cellulose. However, polysaccharide dissolution happened inevitably during the pretreatment. It was found that the simplest model, which assumes that the total polysaccharides were reactive to be dissolved, could not well describe the kinetic behavior of polysaccharide dissolution. A novel pseudo-homogenous kinetic model was thus developed by introducing a parameter termed as "potential dissolution degree" (?(d)) based on the multilayered structure of cell wall. It was found that solid xylan and glucan dissolutions were a first-order reaction with respect to the dissolvable fraction. Due to the delignification action of AcH, polysaccharide dissolutions were enhanced in AcH media compared with those in aqueous system. Acetylizations of cellulose and sugars were also observed, and AcH concentration showed a significant influence on the degree of acetylization. PMID:24215769

Zhao, Xuebing; Morikawa, Yuichi; Qi, Feng; Zeng, Jing; Liu, Dehua

2014-01-01

284

PREPARATION AND CHARACTERIZATION OF ACETIC ACID LIGNIN-BASED EPOXY BLENDS  

Directory of Open Access Journals (Sweden)

Full Text Available Lignin-based epoxy resin (LER was prepared from phenolated lignin (PL and epichlorohydrin (ECH in the presence of sodium hydroxide. The eucalyptus acetic acid lignin (AAL was first reacted with phenol in the presence of sulfuric acid to obtain PL. Then, PL was reacted with ECH in aqueous sodium hydroxide to obtain LER. LER was mixed with diglycidyl ether of bisphenol A (E-44 and then cured with triethylenetetramine (TETA. The initial thermal degradation temperature (Td of the cured epoxy blends decreased with the increase in LER content. The residue ratio at 500 °C of the cured epoxy blends (R500, however, increased with the LER content. The maximum adhesive shear strength of the cured epoxy blends was obtained at 20 wt% of LER. The water absorption of epoxy blends increased with increasing the content of LER. SEM photos showed that increasing the content of LER increased inhomogeneity and porosity of epoxy blends.

Fangeng Chen

2012-05-01

285

Allergic Contact Dermatitis Syndrome Due to Tocopherol Acetate, in Addition to Glycyrrhetinic Acid  

Directory of Open Access Journals (Sweden)

Full Text Available Natural vitamin E is suggested to have an antioxidant function. However, the synthetic form of vitamin E, DL-tocopherol, which has been widely used in topical ointments, may cause allergic contact dermatitis. Here, we report a case of allergic contact dermatitis with erythema multiforme-like eruption caused by a topical ointment. Patch testing indicated a positive allergic reaction to an anti-inflammatory ointment the patient had been using and its ingredient, DL-alpha-tocopheryl acetate (vitamin E. In addition, a positive reaction to glycyrrhetinic acid was observed. Both vitamin E and glycyrrhetinic acid are useful ingredients of topical applications. However, the possibility that both can cause contact dermatitis, albeit rarely, should be considered.

Masaaki Ito

2012-03-01

286

Phosphoric acid purification. Removal of thorium and other chemical species  

International Nuclear Information System (INIS)

Separation techniques like solvent extraction, ion exchange resin retention, precipitation and inorganic adsorption showed very low efficiency in removing thorium from the phosphoric acid. Then the process was directed to the extraction of phosphoric acid with tri-n-butyl phosphate (TBP) for its purification which consequently removed the thorium isotopes. This phosphoric acid purification was established to use the mixer-settler cells in countercurrent system. The operational conditions were defined first in discontinuous tests at the laboratory scale and thereafter consolidated in a continuous unit. (orig.)

287

Synthesis and evaluation of mutual azo prodrug of 5-aminosalicylic acid linked to 2-phenylbenzoxazole-2-yl-5-acetic acid in ulcerative colitis.  

Science.gov (United States)

In this study, the syntheses of 4-aminophenylbenzoxazol-2-yl-5-acetic acid, (an analogue of a known nonsteroidal anti-inflammatory drug [NSAID]) and 5-[4-(benzoxazol-2-yl-5-acetic acid)phenylazo]-2-hydroxybenzoic acid (a novel mutual azo prodrug of 5-aminosalicylic acid [5-ASA]) are reported. The structures of the synthesized compounds were confirmed using infrared (IR), hydrogen-1 nuclear magnetic resonance (1H NMR), and mass spectrometry (MS) spectroscopy. Incubation of the azo compound with rat cecal contents demonstrated the susceptibility of the prepared azo prodrug to bacterial azoreductase enzyme. The azo compound and the 4-aminophenylbenzoxazol-2-yl-5-acetic acid were evaluated for inflammatory bowel diseases, in trinitrobenzenesulfonic acid (TNB)-induced colitis in rats. The synthesized diazo compound and the 4-aminophenylbenzoxazol-2-yl-5-acetic acid were found to be as effective as 5-aminosalicylic acid for ulcerative colitis. The results of this work suggest that the 4-aminophenylbenzoxazol-2-yl-5-acetic acid may represent a new lead for treatment of ulcerative colitis. PMID:23983456

Jilani, Jamal A; Shomaf, Maha; Alzoubi, Karem H

2013-01-01

288

Production of indole-3-acetic acid and related indole derivatives from L-tryptophan by Rubrivivax benzoatilyticus JA2.  

Science.gov (United States)

Rubrivivax benzoatilyticus JA2 produces indoles with simultaneous utilization of L-tryptophan. Fifteen chromatographically distinct indole derivatives were detected from the L-tryptophan-supplemented cultures of R. benzoatilyticus JA2. Nine of these were identified as, indole 3-acetamide, Methoxyindole-3-aldehyde, indole 3-aldehyde, methoxyindole-3-acetic acid, indole 3-acetic acid, indole-3-carboxylic acid, indole-3-acetonitrile, indole, and trisindoline. Tryptophan stable isotope feeding confirmed the indoles produced are from the supplemented L-tryptophan. Indole 3-acetic acid is one of the major products of L-tryptophan catabolism by R. benzoatilyticus JA2 and its production was influenced by growth conditions. Identification of indole 3-acetamide and tryptophan monooxygenase activity suggests indole 3-acetamide routed IAA biosynthesis in R. benzoatilyticus JA2. The study also indicated the possible multiple pathways of IAA biosynthesis in R. benzoatilyticus JA2. PMID:20972782

Mujahid, Md; Sasikala, Ch; Ramana, Ch V

2011-02-01

289

Effect of deuteration of solvent on process of catalytic oxidation of p-xylene and associated decarboxylation of acetic acid  

International Nuclear Information System (INIS)

A study has been made of p-xylene oxidation in the presence of cobalt bromide catalyst and the associated decarboxylation of the solvent when the reaction is carried out in nondeuterated or deuterated acetic acid (CH3COOD or CD3COOD). It has been established that the rate of oxygen absorption is lower when the deuterium is introduced into the carboxyl group of CH3COOH, and the rate of carbon dioxide evolution is increased when deuterium is introduced into the methyl group of the acid. The results prove that the decarboxylation of acetic acid under the reaction conditions in the present work cannot be explained through a mechanism including the formation of a carboxylate radical under the influence of peroxide radicals. Consideration is given to participation of acetic acid in formation of an active catalytic complex, and also to the mechanism of its decarboxylation under the influence of the catalyst

290

Enantioselective Synthesis of Piperidines through the Formation of Chiral Mixed Phosphoric Acid Acetals: Experimental and Theoretical Studies.  

Science.gov (United States)

An enantioselective intramolecular chiral phosphoric acid-catalyzed cyclization of unsaturated acetals has been utilized for the synthesis of functionalized chiral piperidines. The chiral enol ether products of these cyclizations undergo subsequent in?situ enantioenrichment through acetalization of the minor enantiomer. A new computational reaction exploration method was utilized to elucidate the mechanism and stereoselectivity of this transformation. Rather than confirming the originally postulated cyclization proceeding directly through a vinyl oxocarbenium ion, simulations identified an alternative two-step mechanism involving the formation of a mixed chiral phosphate acetal, which undergoes a concerted, asynchronous SN 2'-like displacement to yield the product with stereoselectivity in agreement with experimental observations. PMID:25196818

Sun, Zhankui; Winschel, Grace A; Zimmerman, Paul M; Nagorny, Pavel

2014-10-13

291

Citrate- vs. acetate-based dialysate in bicarbonate haemodialysis: consequences on haemodynamics, coagulation, acid-base status, and electrolytes  

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Abstract Background A concentrate for bicarbonate haemodialysis acidified with citrate instead of acetate has been marketed in recent years. The small amount of citrate used (one-fifth of the concentration adopted in regional anticoagulation) protects against intradialyser clotting while minimally affecting the calcium concentration. The aim of this study was to compare the impact of citrate- and acetate-based dialysates on systemic haemodynamics, coagulation, acid-base statu...

Alberio Lorenzo; Marone Claudio; Lucchini Barbara; Gabutti Luca; Burnier Michel

2009-01-01

292

Developmental toxicity of mixtures: the water disinfection by-products dichloro-, dibromo- and bromochloro acetic acid in rat embryo culture  

Science.gov (United States)

The chlorination of drinking water results in production of numerous disinfection by-products (DBPs). One of the important classes of DBPs is the haloacetic acids. We have previously shown that the haloacetic acids (HAs), dichloro (DCA), dibromo (DBA) and bromochloro (BCA) acetic...

293

PHOTOLYSIS RATES OF (2,4,5-TRICHLOROPHENOXY)ACETIC ACID AND 4-AMINO-3,5,6-TRICHLOROPICOLINIC ACID IN NATURAL WATERS  

Science.gov (United States)

Photoreactions of (2,45-trichlorophenoxy) acetic acid (2,4,5-T) and 4-amino-3,5,6-trichloropicolinic acid (picloram) were studied in distilled water, natural water samples, fulvic acid solutions, and solutions containing iron (III) and/or hydrogen peroxide to determine the effect...

294

Production of Acetic Acid from Carbohydrate Biomass by Two-Step Reaction with Alkaline Hydrothermal Reaction and Wet Oxidation  

Science.gov (United States)

An investigation was carried out to improve the production of acetic acid by an alkaline two-step process, in which the first step is to accelerate the formation of lactic acid in a hydrothermal reaction with the addition of alkali, and the second step is further convert the lactic acid produced in the first step to acetic acid by oxidation with newly added oxygen. Results showed that the addition of alkali promoted selectively the formation of lactic acid from glucose at a hydrothermal condition. Acetic acid yield in the alkaline two-step process greatly increased in comparison to that without the addition of any alkali. In the alkaline two-step process, the highest acetic acid yield arrived at 27 % on the carbon base under the conditions of reaction temperature of 300 °C, reaction time of 1 min, and Ca(OH)2 concentration of 0.32 M in the first step, and reaction temperature of 300 °C, reaction time of 3 min, and oxygen supply of 70 % in the second step.

Yan, X.; Jin, F.; Tohji, K.; Enomoto, H.

2007-03-01

295

Changes in Growth, Auxin- and Ribonucleic Acid Metabolism in Wheat Coleoptile Sections Following Pulse Treatment with Indole-3-Acetic Acid  

DEFF Research Database (Denmark)

Growth reactions of wbeat coleoptile sections following a brief pretreament in indole-3-acetic acid (LAA) were studied. The growth versus concentration curves 24 hours after the treatment showed a minimum value surrounded by bigber values. The minimum was never at concentrations lower than 10-5M lAA but it could be found at higher concentrations after short pretreatment periods. The growth versus time curves reveated that the hormone treatment cansed the growth rate initially to increase but later on to decrease. The decrease was followed by a second increase for some treatments. Analysis of IAA content after the pretreatment showed that the attered growth patterns could be ascribed to declining auxin content with time, but not to thc actual concentration in the sections. The results indicate that the metabolic activation brought about by IAA leads to its own disappearance. Such a phenomenon was mirroretl in effects of IAA on hte net synthesis of ribonucleic acid.

Truelsen, T.A.; Galston, A.W.

1966-01-01

296

Nitric acid vapor removal by activated, impregnated carbons  

Energy Technology Data Exchange (ETDEWEB)

Laboratory and industrial workers can be exposed to vapors of nitric acid, especially in accidents, such as spills. Nitric acid can also be a product of incineration for energy production or waste (e.g., CW agent) disposal. Activated carbons containing impregnants for enhancing vapor and gas removal have been tested for effectiveness in removing vapors of nitric acid from air. The nitric acid vapor was generated from concentrated acid solutions and detected by trapping in a water bubbler for pH measurements. Both low and moderate relative humidity conditions were used. All carbons were effective at vapor contact times representative of air-purifying respirator use. One surprising observation was the desorption of low levels of ammonia from impregnated carbons. This was apparently due to residual ammonia from the impregnation processes.

Wood, G.O.

1996-12-31

297

Understanding the dissolution of ?-zein in aqueous ethanol and acetic acid solutions.  

Science.gov (United States)

Zein is a corn prolamin that has broad industrial applications because of its unique physical properties. Currently, the high cost of extraction and purification, which is directly related to the dispersion of zein in different solvents, is the major bottleneck of the zein industry. Solution behaviors of zein have been studied for a long time. However, the physical nature of zein in different solvents remains unclear. In this study, small-angle X-ray scattering (SAXS), static light scattering (SLS), and rheology were combined to study the structure and protein-solvent interaction of ?-zein in both acetic acid and aqueous ethanol solutions. We found that the like-dissolve-like rule, the partial unfolding, and the protonation of zein are all critical to understanding the solution behaviors. Zein holds an elongated conformation (i.e., prolate ellipsoid) in all solutions, as revealed from SAXS data. There is an "aging effect" for zein in aqueous ethanol solutions, as evidenced by the transition of Newtonian rheological profiles for fresh zein solutions to the non-Newtonian shear thinning behavior for zein solutions after storage at room temperature for 24 h. Such shear thinning behavior becomes more pronounced for zein solutions at higher concentrations. The SLS results clearly show that acetic acid is a better solvent to dissolve zein than aqueous ethanol solution, as supported by a more negative second virial coefficient. This is majorly caused by the protonation of the protein, which was further verified by the dissolution of zein in water (a nonsolvent for zein) with the addition of acids. PMID:22973883

Li, Yunqi; Li, Ji; Xia, Qiuyang; Zhang, Boce; Wang, Qin; Huang, Qingrong

2012-10-01

298

REMOVAL OF CHLORIDE FROM ACIDIC SOLUTIONS USING NO2  

Energy Technology Data Exchange (ETDEWEB)

Chloride (Cl{sup -}) salt processing in strong acids is used to recycle plutonium (Pu) from pyrochemical residues. The Savannah River National Laboratory (SRNL) is studying the potential application of nitrogen dioxide (NO{sub 2}) gas to effectively convert dissolved pyrochemical salt solutions to chloride-free solutions and improve recovery operations. An NO{sub 2} sparge has been shown to effectively remove Cl{sup -} from solutions containing 6-8 M acid (H{sup +}) and up to 5 M Cl{sup -}. Chloride removal occurs as a result of the competition of at least two reactions, one which is acid-dependent. Below 4 M H+, NO2 reacts with Cl- to produce nitrosyl chloride (ClNO). Between 6 M and 8 M H{sup +}, the reaction of hydrochloric acid (HCl) with nitric acid (HNO{sub 3}), facilitated by the presence of NO{sub 2}, strongly affects the rate of Cl{sup -} removal. The effect of heating the acidic Cl{sup -} salt solution without pre-heating the NO{sub 2} gas has minimal effect on Cl{sup -} removal rates when the contact times between NO{sub 2} and the salt solution are on the order of seconds.

Visser, A; Robert Pierce, R; James Laurinat, J

2006-08-22

299

Growth inhibitory effect of grape phenolics against wine spoilage yeasts and acetic acid bacteria.  

Science.gov (United States)

This paper investigates the in vitro antimicrobial potential of 15 grape phenolic compounds of various chemical classes (phenolic acids, stilbenes and flavonoids) using the broth microdilution method against yeasts and acetic acid bacteria frequently occurring in deteriorated wine. Pterostilbene (MICs=32-128 ?g/mL), resveratrol (MICs=256-512 ?g/mL) and luteolin (MICs=256-512 ?g/mL) are among six active compounds that possessed the strongest inhibitory effects against all microorganisms tested. In the case of phenolic acids, myricetin, p-coumaric and ferulic acids exhibited selective antimicrobial activity (MICs=256-512 ?g/mL), depending upon yeasts and bacteria tested. In comparison with potassium metabisulphite, all microorganisms tested were more susceptible to the phenolics. The results revealed the antibacterial and antiyeast effects against wine spoilage microorganisms of several highly potent phenolics naturally occurring in grapes. These findings also provide arguments for further investigation of stilbenes as prospective compounds reducing the need for the use of sulphites in winemaking. PMID:23334100

Pastorkova, E; Zakova, T; Landa, P; Novakova, J; Vadlejch, J; Kokoska, L

2013-02-15

300

Effects of Pfaffia glomerata (Spreng) pedersen aqueous extract on healing acetic acid-induced ulcers  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Pfaffia glomerata (Spreng) Pedersen (Amaranthaceae), uma planta conhecida popularmente como "Ginseng Brasileiro" e "paratudo", é utilizada para tratar distúrbios gástricos e como cicatrizante. Em estudos anteriores, foi demonstrado que o extrato aquoso bruto da P. glomerata (AEP) protegeu a mucosa g [...] ástrica contra úlceras induzidas por etanol e estresse e reduziu a secreção ácida gástrica basal e estimulada em ratos com ligadura de piloro. Além disso, a secreção gástrica de animais tratados com AEP apresentou níveis de nitrato e nitrito aumentados. O objetivo deste estudo foi avaliar se o AEP previne o desenvolvimento de úlceras induzidas por ácido acético e o efeito desse extrato no processo de cicatrização em úlceras previamente formadas. A administração do AEP em diferentes doses produziu efeitos tóxicos baixos e não preveniu a formação de úlceras, porém aumentou o processo de cicatrização em úlceras já existentes, como evidenciado no estudo histopatológico. Em conclusão, o AEP administrado cronicamente promove o aumento da cicatrização do tecido após a lesão induzida com o ácido acético. Abstract in english The present study was carried out to evaluate the acute toxicity and the effect of the aqueous extract of the roots from Pfaffia glomerata (Spreng) Pedersen (Amaranthaceae) (AEP) on the prevention of acetic acid-induced ulcer and on the healing process of previously induced ulcers. The acute toxicit [...] y was evaluated in Swiss mice after oral administration of a single dose and the chronic gastric ulcer was induced with local application of acetic acid. The results showed that the LD50 of the extract was 684.6 mg.kg-1 for the intraperitoneal administration and higher than 10 mg.kg-1by the oral route. The administration of the AEP did not prevent ulcers formation. However, the AEP increased of the healing process of previously induced ulcers. The results suggest that AEP chronically administered promote an increase of tissue healing, after the damage induced by acetic acid and the extract seemed to be destituted of toxic effects in the mice by the oral route.

Cristina Setim, Freitas; Cristiane Hatsuko, Baggio; Samanta Luiza, Araújo; Maria Consuelo Andrade, Marques.

 
 
 
 
301

Suppressing glucose uptake and acetic acid production increases membrane protein overexpression in Escherichia coli  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The production of integral membrane spanning proteins (IMP's constitutes a bottleneck in pharmaceutical development. It was long considered that the state-of-the-art was to produce the proteins as inclusion bodies using a powerful induction system. However, the quality of the protein was compromised and the production of a soluble protein that is incorporated into the membrane from which it is extracted is now considered to be a better method. Earlier research has indicated that a slower rate of protein synthesis might overcome the tendency to form inclusion bodies. We here suggest the use of a set of E. coli mutants characterized by a slower rate of growth and protein synthesis as a tool for increasing the amount of soluble protein in high- throughput protein production processes. Results A set of five IMP's was chosen which were expressed in three mutants and the corresponding WT cell (control. The mutations led to three different substrate uptake rates, two of which were considerably slower than that of the wild type. Using the mutants, we were able to express three out of the five membrane proteins. Most successful was the mutant growing at 50% of the wild type growth rate. A further effect of a low growth rate is a low acetic acid formation, and we believe that this is a possible reason for the better production. This hypothesis was further supported by expression from the BL21(DE3 strain, using the same plasmid. This strain grows at a high growth rate but nevertheless yields only small amounts of acetic acid. This strain was also able to express three out of the five IMP's, although at lower quantities. Conclusions The use of mutants that reduce the specific substrate uptake rate seems to be a versatile tool for overcoming some of the difficulties in the production of integral membrane spanning proteins. A set of strains with mutations in the glucose uptake system and with a lower acetic acid formation were able to produce three out of five membrane proteins that it was not possible to produce with the corresponding wild type.

Larsson Gen

2011-05-01

302

Metal-organic coordination architectures of azole heterocycle ligands bearing acetic acid groups: Synthesis, structure and magnetic properties  

Science.gov (United States)

Four new coordination complexes with azole heterocycle ligands bearing acetic acid groups, [Co( L1) 2] n ( 1) , [Cu L1N 3] n ( 2), [Cu( L2) 2·0.5C 2H 5OH·H 2O] n ( 3) and [Co( L2) 2] n ( 4) (here, H L1=1H-imidazole-1-yl-acetic acid, H L2=1H-benzimidazole-1-yl-acetic acid) have been synthesized and structurally characterized. Single-crystal structure analysis shows that 3 and 4 are 2D complexes with 4 4-sql topologies, while another 2D complex 1 has a (4 3) 2(4 6)-kgd topology. And 2 is a 3D complex composed dinuclear ?1,1-bridging azido Cu II entities with distorted rutile topology. The magnetic properties of 1 and 2 have been studied.

Hu, Bo-Wen; Zhao, Jiong-Peng; Yang, Qian; Hu, Tong-Liang; Du, Wen-Ping; Bu, Xian-He

2009-10-01

303

Protective Effect of Alpha-lipoic Acid Against Lead Acetate-Induced Oxidative Stress in the Bone Marrow of Rats  

Directory of Open Access Journals (Sweden)

Full Text Available The present study was designed to investigate the effects of alpha Lipoic Acid (LA against lead acetate induced changes in free radical scavenging enzymes and lipid hydroperoxides in bone marrow of rats. Rats were exposed to lead acetate in their drinking water (500 ppm for 14 days and alpha lipoic acid was given concurrently (25, 50 and 100 mg kg-1. Blood lead levels, lipid hydroperoxides, protein carbonyl contents and oxidative marker enzymes were estimated. Lead acetate in drinking water had elicited a significant (p-1 b.wt. LA. The potency of alpha lipoic acid on the reversal of lead induced changes in oxidative biomarkers in bone marrow confirms the importance of lead induced oxidative stress in bone and suggests a therapeutic approach.

Srikumar Chakravarthi

2011-01-01

304

Vapor phase ketonization of acetic acid on ceria based metal oxides  

Energy Technology Data Exchange (ETDEWEB)

The activities of CeO2, Mn2O3-CeO2 and ZrO2-CeO2 were measured for acetic acid ketonization under reaction conditions relevant to pyrolysis vapor upgrading. We show that the catalyst ranking changed depending on the reaction conditions. Mn2O3-CeO2 was the most active catalyst at 350 oC, while ZrO2 - CeO2 was the most active catalyst at 450 oC. Under high CO2 and steam concentration in the reactants, Mn2O3-CeO2 was the most active catalyst at 350 and 450 °C. The binding energies of steam and CO2 with the active phase were calculated to provide the insight into the tolerance of Mn2O3-CeO2 to steam and CO2.

Liu, Changjun; Karim, Ayman M.; Lebarbier, Vanessa MC; Mei, Donghai; Wang, Yong

2013-12-01

305

Ultrastructure of sheep primordial follicles cultured in the presence of indol acetic acid, EGF, and FSH  

DEFF Research Database (Denmark)

The aim of this study was to investigate the ultrastructural characteristics of primordial follicles after culturing of sheep ovarian cortical slices in the presence of indol acetic acid (IAA), Epidermal Growth Factor (EGF), and FSH. To evaluate ultrastructure of primordial follicles cultured in MEM (control) or in MEM containing IAA, EGF, and FSH, fragments of cultured tissue were processes for transmission electron microscopy. Except in the control, primordial follicles cultured in supplemented media for 6¿d were ultrastructurally normal. They had oocyte with intact nucleus and the cytoplasm contained heterogeneous-sized lipid droplets and numerous round or elongated mitochondria with intact parallel cristae were observed. Rough endoplasmic reticulum (RER) was rarely found. The granulosa cells cytoplasm contained a great number of mitochondria and abundant RER. In conclusion, the presence of IAA, EGF, and FSH helped to maintain ultrastructural integrity of sheep primordial follicles cultured in vitro.

Andrade, Evelyn Rabelo; Hyttel, Poul

2011-01-01

306

Indole acetic acid and its metabolism in root nodules of a monocotyledonous tree Roystonea regia.  

Science.gov (United States)

A monocotyledonous tree, Roystonea regia, was found to bear root nodules. The root nodules contained a high amount (16.9 microg/g fresh mass) of indole acetic acid (IAA). A big tryptophan pool (1555.1 microg/g fresh mass) was found in the root nodules, which might serve as a source of IAA production. The presence of IAA-metabolizing enzymes IAA oxidase and peroxidase indicated metabolism of IAA in the root nodules. The symbiont isolated from the root nodules of R. regia, a Rhizobium sp., produced high amount of IAA in culture when supplemented with tryptophan. The possible role of this IAA production in the monocotyledonous tree-Rhizobium symbiosis is discussed. PMID:9662615

Basu, P S; Ghosh, A C

1998-08-01

307

One-component thioxanthone acetic acid derivative photoinitiator for free radical polymerization.  

Science.gov (United States)

Acetic acid-based thioxanthone (TXCH2 COOH) was synthesized and characterized and used as a photoinitiator for free radical photopolymerization of methyl methacrylate (MMA) in the absence and presence of a tertiary amine (MDEA) in different solvents. Different absorption properties were observed depending on the solvent. Fluorescence and phosphorescence experiments were also carried out successfully. The fluorescence quantum yield was found to be 0.09 and the phosphorescence lifetime was calculated as 138 ms at 77 K. The photoinitiator undergoes efficient intersystem crossing into the triplet state and the lowest triplet state possesses ?-?* configuration. Laser flash photolysis experiments show that transient absorption of TXCH2 COOH is similar to the parent thioxanthone and the triplet lifetime was calculated as 2.3 ?s at 630 nm. PMID:24372104

Esen, Duygu S; Temel, Gokhan; Balta, Demet K; Allonas, Xavier; Arsu, Nergis

2014-01-01

308

Utilization of Vinegar for Isolation of Cellulose Producing Acetic Acid Bacteria  

Science.gov (United States)

Wastes of traditionally fermented Turkish vinegar were used in the isolation of cellulose producing acetic acid bacteria. Waste material was pre-enriched in Hestrin-Schramm medium and microorganisms were isolated by plating dilution series on HS agar plates The isolated strains were subjected to elaborate biochemical and physiological tests for identification. Test results were compared to those of reference strains Gluconacetobacter xylinus DSM 46604, Gluconacetobacter hansenii DSM 5602 and Gluconacetobacter liquefaciens DSM 5603. Seventeen strains, out of which only three were found to secrete the exopolysaccharide cellulose. The highest cellulose yield was recorded as 0.263±0.02 g cellulose L-1 for the strain AS14 which resembled Gluconacetobacter hansenii in terms of biochemical tests.

Aydin, Y. Andelib; Aksoy, Nuran Deveci

2010-06-01

309

Utilization of Vinegar for Isolation of Cellulose Producing Acetic Acid Bacteria  

International Nuclear Information System (INIS)

Wastes of traditionally fermented Turkish vinegar were used in the isolation of cellulose producing acetic acid bacteria. Waste material was pre-enriched in Hestrin-Schramm medium and microorganisms were isolated by plating dilution series on HS agar plates The isolated strains were subjected to elaborate biochemical and physiological tests for identification. Test results were compared to those of reference strains Gluconacetobacter xylinus DSM 46604, Gluconacetobacter hansenii DSM 5602 and Gluconacetobacter liquefaciens DSM 5603. Seventeen strains, out of which only three were found to secrete the exopolysaccharide cellulose. The highest cellulose yield was recorded as 0.263±0.02 g cellulose L-1 for the strain AS14 which resembled Gluconacetobacter hansenii in terms of biochemical tests.

310

Dichromate dosimetry. The effect of acetic acid on the radiolytic reduction yield  

International Nuclear Information System (INIS)

ced H2O2 with dichromate. There is also in both O2- and N2-saturated solution a long-term slow reaction involving oxidation of the organic substrate (in this case, acetic acid). Because of these instabilities, the solutions cannot readily be used for dosimetry without the presence of silver ions, which in the oxidized state, Ag2+, act to stabilize the solution after irradiation. The addition of silver dichromate at a concentration of 0.1 mM decreases the yield to G:-(Cr2O7) 2-] = 0.17 ?mol J-1, but greatly improves the stability of the solution after irradiation. The absorbed dose range for the modified dichromate dosimeter when analyzed spectrophotometrically at 350 nm wavelength is approx. 2 x 102-2 x 103Gy. (author)

311

Coupled hydrogen-bonding interactions between beta-carboline derivatives and acetic acid.  

Science.gov (United States)

In this work, we have analysed the tendency of two beta-carboline derivatives, harmane and norharmane, in the formation of hydrogen bonds. We obtained the (1)H and (13)C NMR spectra of different mixtures of these derivatives with acetic acid (AcOH) in CDCl(3). A cyclic 1:3 complex is proposed between harmane and AcOH, while a 1:2 complex is proposed for norharmane. Chemical shifts at temperatures between 233 and 323 K were measured: lowering the temperature produces the same effect as increasing the amount of AcOH in solution. The (13)C data confirm a delocalisation of the pi electron density towards the pyridinic ring that occurs when AcOH is added. PMID:17729214

Reyman, D; Hallwass, F; Gonçalves, Simone M da Cruz; Camacho, J J

2007-10-01

312

Exponential decay activities of radiocesium In mushrooms by the help of acetic acid  

International Nuclear Information System (INIS)

Gross activity of radiocesium in food from environmental ecosystems is decreasing slower than it was supposed and therefore it is subject for public repeatedly. Belong there mushrooms, game and wood fruits. Interest in this problems is and substantial improvement tighten up admissible levels of radioactive contamination of food (137Cs and 134Cs) for irradiation after Chernobyl in public notice for Czech republic is 600 Bq/kg. It is in unity with European Union. We can search possibilities to decrease content of radiocesium in food. Mainly mushrooms cumulate considerable quantity of radiocesium. Were examined samples Boletus badius of three other condition. Samples come from two other localities. Activity of radiocesium was detected by gamma-spectrometry (f.Canberra). For decrease content of radiocesium was using elution in 2% solution of acetate acid. Curve of graphic analysis have exponential nature. (authors)

313

Substituted naphthalen-1-yl-acetic acid hydrazides: synthesis, antimicrobial evaluation and QSAR analysis.  

Science.gov (United States)

A series of naphthalen-1-yl-acetic acid benzylidene/(1-phenyl-ethylidene)-hydrazides (1-36) was synthesized and tested, in vitro, for antiviral, antibacterial and antifungal activities. The antibacterial and antifungal screening results indicated that compounds having o-bromo, methoxy and hydroxy substitutents were the most active ones. The results of antiviral evaluation showed that none of the synthesized derivatives inhibited the viral infection at subtoxic concentrations. QSAR investigations revealed that the multi-target QSAR model was more effective in describing the antimicrobial activity than the one-target QSAR models. Further, it revealed the importance of the partition coefficient (log P) followed by energies of the highest occupied molecular orbital (HOMO) and topological parameters, molecular connectivity indices (1?, 3? and 3?v) in describing the antimicrobial activity of substituted hydrazides. PMID:22762164

Narang, Rakesh; Narasimhan, Balasubramanian; Sharma, Sunil; De Clercq, Erik; Pannecouque, Christophe; Balzarini, Jan

2013-03-01

314

Isotopic composition of Murchison organic compounds: Intramolecular carbon isotope fractionation of acetic acid. Simulation studies of cosmochemical organic syntheses  

Science.gov (United States)

Recently, in our laboratories, samples of Murchison acetic acid were decarboxylated successfully and the carbon isotopic composition was measured for the methane released by this procedure. These analyses showed significant differences in C-13/C-12 ratios for the methyl and carboxyl carbons of the acetic acid molecule, strongly suggesting that more than one carbon source may be involved in the synthesis of the Murchison organic compounds. On the basis of this finding, laboratory model systems simulating cosmochemical synthesis are being studied, especially those processes capable of involving two or more starting carbon sources.

Yuen, G. U.; Cronin, J. R.; Blair, N. E.; Desmarais, D. J.; Chang, S.

1991-01-01

315

Production of acetic acid from ethanol solution by acetobactor acetigenum and effect of gamma-ray irradiation on the bacteria  

International Nuclear Information System (INIS)

A preliminary study on fermentation of acetic acid by S. cerevisiae and A. acetigenum was carried out to obtain information to develop the effective utilization technology of agricultural liquid wastes. Aqueous solutions of glucose and/or ethanol were used as a model of agricultural liquid waste. The effect of gamma-ray irradiation on A. acetigenum for enhancement of the fermentation was also examined. In this study, irradiated A. acetigenum had activity to produce acetic acid even after loss the activity to grow. (author)

316

Design, synthesis and anti-mycobacterial activity of 1,2,3,5-tetrasubstituted pyrrolyl-N-acetic acid derivatives.  

Science.gov (United States)

A novel synthesis of highly substituted pyrrole-N-acetic derivatives is described through the coupling of 1,4-diketones with amino acids following Paal-Knorr's approach. These pyrrole-N-acetic acid derivatives are found to exhibit potent anti-mycobacterial activity against Mycobacterium smegmatis and Mycobacterium tuberculosis strain H37Rv. In particular, 5n, 5q &5r are found to display excellent anti-mycobacterial activity against M. tuberculosis strain H37Rv with MIC values in the range of 2.97 ?M. Conversely, these compounds showed low cytotoxicity (selectivity index: >16.83) against HEK-293T cell line. PMID:25016370

Pagadala, Lakshmi Reddy; Mukkara, Lakshmi Devi; Singireddi, Satyanarayana; Singh, Ashita; Thummaluru, Veera Reddy; Jagarlamudi, Padma Sridevi; Guttala, Raja Sekhar; Perumal, Yogeeswari; Dharmarajan, Sriram; Upadhyayula, Suryanarayana Murty; Ummanni, Ramesh; Basireddy, Venkata Subba Reddy; Ravirala, Narender

2014-09-12

317

Role of Visual Inspection of Cervix with Acetic Acid (VIA in Detecting Precancerous Lesions of Cervix  

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Full Text Available Background: Carcinoma of cervix is the most common malignancy in female and a major public health problem worldwide. It is the leading cause of death from cancer among women in low resource settings. In Bangladesh, mortality rate is high as most of the cases with cervical cancer are diagnosed in advanced stage. World Health Organization considers cervical cancer as a preventable disease as it can be identified in preinvasive stage. Considerable efforts have been given in detection and treatment of the condition all over the world. A number of cervical cancer screening tests are available. Among them, visual inspection of cervix with acetic acid is rational and can be competently performed by physicians with proper training. Objective: To find out the feasibility of the visual inspection of cervix with acetic acid for the detection of the precancerous lesions of the cervix in our country. Materials and Methods: This cross sectional, analytical study was carried out among the patients attending the outpatient department of Bangabandhu Sheikh Mujib Medical University (BSMMU who were VIA positive and sent for colposcopy in the colposcopy clinic in the department of Obstetrics and Gynecology in BSMMU from June to December 2004. Two hundred samples were considered for this study. Results: Out of 200 cases, colposcopically 85% had CIN and invasive lesions, 4% had inflammatory lesions while 11% had normal findings. Colposcopy directed punch biopsy revealed positive lesions in 81%, 4% had inflammatory lesions while 15% had normal findings. Conclusion: The study concluded that VIA and colposcopy are the important methods in the evaluation of cervical premalignancy. VIA may be an important tool for screening of cervical cancer in low resource settings as it is simple, easy to perform and cost-effective. After screening, VIA positive cases must be referred for colposcopic evaluation. We can screen cervical cancer by VIA all over the country and thus reduce morbidity and mortality rate.

Kamrun Nessa

2014-01-01

318

Acridone acetic acid, sodium salt, as an agent to stop vitiligo progression: a pilot study.  

Science.gov (United States)

Vitiligo progression is attributed to immune system malfunctioning, thus immunomodulating compounds might be beneficial in stopping vitiligo progression which is a prerequisite for successful repigmentation. The goal of this study was to assess efficacy of acridone acetic acid, sodium salt (Na-AAA), an immunomodulating compound with favorable safety profile, in stabilizing active vitiligo, and to reveal prognostic factors of treatment outcome. Sixty consecutive patients with progressing nonsegmental vitiligo were treated with 10 i.m. injections of Na-AAA every other day. Disease stability was assessed in 1, 3, 6, and 12 months post-treatment. Statistical analysis was applied to correlate treatment outcome and available clinical parameters. Of the 60 patients treated, vitiligo stopped progression in 44 patients (73.3%). Older age (p = 0.0219), age of 35 and older (p = 0.0189, odds ratio (OR) = 5.2, 95% confidence interval (CI) 1.30-20.84) or age of 40 and older (p = 0.0039, OR = 6.48, 95% CI 1.86-22.61), longer disease duration (p = 0.0234), pre-treatment interleukin-6 level over 2?pg/mL (p = 0.0005, OR = 13.7, 95% CI 2.97-63), and over the reference threshold value 5.9?pg/mL (p = 0.0009, OR = 25.8, 95% CI 2.8-239) as well as presence of other autoimmune diseases (p = 0.038, OR = 7.0, 95% CI 1.14-42.97) were negative prognostic factors of treatment success. In conclusion, acridone acetic acid, sodium salt, emerges as an efficient option for stopping vitiligo progression. PMID:24548590

Korobko, Igor V; Lomonosov, Konstantin M

2014-01-01

319

Reversal of meconium inhibition of pulmonary surfactant by ferric chloride, copper chloride, and acetic acid.  

Science.gov (United States)

Meconium inhibits pulmonary surfactant function. We investigated the in vitro effect of meconium on three different commercial surfactants. The dynamic surface properties of these surfactants were evaluated at the concentration of 5 mg/ml with a pulsating bubble system. The inhibitory effect of 2.75 mg/ml meconium was significantly less on Alveofact than on Curosurf and Survanta. Ferric chloride and copper chloride completely reversed the inhibitory effect of meconium. Meconium also prevented effective spreading of surfactant in a Wilhelmy balance system, and this inhibitory effect was counteracted by addition of ferric chloride. Image analysis of Curosurf demonstrated that meconium reduced the total number of microbubbles in 15 light-microscopic fields (4.35 mm(2)) from 1,748 +/- 481 to 180 +/- 166. Ferric chloride restored the number of microbubbles. Addition of ferric chloride or copper chloride to surfactant/meconium lowers pH, and pH adjustment by acetic acid also reversed the inhibitory effect of meconium. Together with the fact that the iron-chelator deferoxamine did not attenuate the effect of ferric chloride this suggests that the observed contrainhibition is caused by lowering of pH, and that meconium inhibition of surfactant is pH-dependent. Lowering pH from 6.2 to 5-5.5 abolished the inhibitory effects of meconium on surfactant. Inhibition of 2.5 mg/ml of Curosurf with plasma could also be reversed by increasing amounts of ferric chloride. We conclude that the inhibitory effect of meconium on surfactant in vitro can be abolished by addition of ferric chloride, copper chloride, or acetic acid. PMID:11069814

Almaas, R; Robertson, B; Linderholm, B; Lundberg, E; Saugstad, O D; Moen, A

2000-11-01

320

Synthesis of silica xerogels with high surface area using acetic acid as catalyst  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Nesse trabalho foi estudada a influência do ácido acético na estrutura de poros e na área superficial de sílicas preparadas pelo método sol-gel. Condições experimentais de síntese, tais como temperatura de policondensação e solventes, também foram estudadas. Isotermas de adsorção de N2 das amostras [...] foram classificadas como do tipo 1, típicas de materiais microporosos, o que explica os altos valores de área superficial obtidos. A adição simultânea dos ácidos acético e clorídrico como catalisadores e de acetona como solvente, bem como o emprego de uma temperatura de policondensação de 20 ºC, possibilitaram a preparação de sílicas amorfas com valores de área superficial de até 850 m² g-1. O alto valor de área superficial dessas amostras pode ser explicado principalmente pela microporosidade e também pelo tamanho nanométrico das partículas. Abstract in english The influence of acetic acid on the pore structure and surface area of silica prepared by the sol-gel method was investigated. Experimental conditions of synthesis, such as gelation temperature and solvents, were also studied. N2 adsorption isotherms of the samples were type 1, typical of microporou [...] s materials, explaining the high surface area values (BET) observed. The simultaneous addition of acetic and hydrochloric acids as catalysts and of acetone as solvent, together with the use of a gelation temperature of 20 ºC, made it possible to prepare amorphous silica materials with surface area values up to 850 m² g-1. The high surface area value of these samples could be explained by the microporosity and the nanometric size of the particles.

Leliz T., Arenas; Carolina W., Simm; Yoshitaka, Gushikem; Silvio L. P., Dias; Celso C., Moro; Tania M. H., Costa; Edilson V., Benvenutti.

 
 
 
 
321

Anti-inflammatory effect of Helichrysum oligocephalum DC extract on acetic acid -- Induced acute colitis in rats  

Science.gov (United States)

Background: Helichrysum oligocephalum DC. from Asteraceae family is an endemic plant growing wild in Iran. This study was carried out to investigate the effect of H. oligocephalum hydroalcoholic extract (HOHE) on ulcerative colitis (UC) induced by acetic acid (AA) in rats. Materials and Methods: Rats were grouped (n = 6) and fasted for 24 h before colitis induction. Treatments were started 2 h before the induction of colitis and continued for two consecutive days with different doses of HOHE (100, 200, and 400 mg/kg) orally (p.o.) and intraperitoneally (i.p.). The colon tissue was removed and tissue damages were scored after macroscopic and histopathologic assessments. Results: Among the examined doses of HOHE, 100 mg/kg was the most effective dose that reduced the extent of UC lesions and resulted in significant alleviation. Weight/length ratio as an index of tissue inflammation and extravasation was also diminished in the treatment group administered HOHE at a dose of 100 mg/kg, and the results showed correlation with macroscopic and histopathologic evaluations. These data suggest that HOHE (100 mg/kg) administered either p.o. or i.p. was effective in diminishing inflammation and ulcer indices in this murine model of acute colitis in a non–dose-related manner. Conclusions: H. oligocephalum could be considered as a suitable anticolitis alternative; however, further studies are needed to support this hypothesis for clinical setting. PMID:24761395

Minaiyan, Mohsen; Ghassemi-Dehkordi, Nasrollah; Mahzouni, Parvin; Ahmadi, Najme-Sadat

2014-01-01

322

Seasonality Influence in the Distribution of Formic and Acetic Acids in the Urban Atmosphere of São Paulo City, Brazil  

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Full Text Available Ambient levels and diurnal profiles of formic and acetic acids were measured in the atmosphere of São Paulo City in winter and spring 1996. A comparison between two different urban sites was done. Results demonstrate that carboxylic acid levels were affected by seasonality in the site with high vehicular emission density, while no seasonal influence was observed for the other site studied. Ranges of mixing ratios from 0.64 to 11.8 ppbv for formic acid and 0.51 to 10.7 ppbv for acetic acid were recorded. The results concerning the carboxylic acid concentrations were discussed with respect to direct emission and in situ photochemical production.

Souza Silvia R.

2001-01-01

323

Effect of acetic acid present in bagasse hydrolysate on the activities of xylose reductase and xylitol dehydrogenase in Candida guilliermondii.  

Science.gov (United States)

The first two steps in xylose metabolism are catalyzed by NAD(P)H-dependent xylose reductase (XR) (EC 1.1.1.21) and NAD(P)-dependent xylitol dehydrogenase (XDH) (EC 1.1.1.9), which lead to xylose-->xylitol-->xylulose conversion. Xylitol has high commercial value, due to its sweetening and anticariogenic properties, as well as several clinical applications. The acid hydrolysis of sugarcane bagasse allows the separation of a xylose-rich hemicellulosic fraction that can be used as a substrate for Candida guilliermondii to produce xylitol. However, the hydrolysate contains acetic acid, an inhibitor of microbial metabolism. In this study, the effect of acetic acid on the activities of XR and XDH and on xylitol formation by C. guilliermondii were studied. For this purpose, fermentations were carried out in bagasse hydrolysate and in synthetic medium. The activities of XR and XDH were higher in the medium containing acetic acid than in control medium. Moreover, none of the fermentative parameters were significantly altered during cell culture. It was concluded that acetic acid does not interfere with xylitol formation since the increase in XR activity is proportional to XDH activity, leading to a greater production of xylitol and its subsequent conversion to xylulose. PMID:15107950

Lima, Luanne Helena Augusto; das Graças de Almeida Felipe, Maria; Vitolo, Michele; Torres, Fernando Araripe Gonçalves

2004-11-01

324

Enhancement of organic solar cells efficiency with acetic acid modulated poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) buffer layers.  

Science.gov (United States)

Bulk-heterojunction organic solar cells (OSCs) based on poly(3-hexylthiophene) as a donor material and (6.6) phenyl-C61-butyric acid methyl ester as an acceptor material were investigated using a poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) buffer layer that was modulated with acetic acid. The 1.71 x 10(-1) omega x cm resistivity of the pristine PEDOT:PSS film decreased to 2.29 x 10(-2) omega x cm when acetic acid was applied. This modified PEDOT:PSS buffer layer improved the power conversion efficiency (PCE) of OSCs by reducing their already low series resistance and contact resistance. The PCE of OSCs in which the PEDOT:PSS buffer layers had been treated with acetic acid was 2.91%, an improvement over the 1.82% PCE for cells with pristine PEDOT:PSS layers. We optimized the ratio of acetic acid and PEDOT:PSS solution for high PCE of OSCs in this manuscript. The value of this modification method for hole transporting layer is clearly demonstrated and be applicable to other organic devices. PMID:24758027

Oh, Sang Hoon; Heo, Seung Jin; Kim, Hyun Jae

2014-07-01

325

Evaluation of the tolerance of acetic acid and 2-furaldehyde on the growth of Pichia stipitis and its respiratory deficient.  

Science.gov (United States)

The use of lignocellulosic residues for ethanol production is limited by toxic compounds in fermenting yeasts present in diluted acid hydrolysates like acetic acid and 2-furaldehyde. The respiratory deficient phenotype gives the cell the ability to resist several toxic compounds. So the aim of this work was to evaluate the tolerance to toxic compounds present in lignocellulosic hydrolysates like acetic acid and 2-furaldehyde in Pichia stipitis and its respiratory deficient strains. The respiratory deficient phenotype was induced by exposure to chemical agents such as acriflavine, acrylamide and rhodamine; 23 strains were obtained. The selection criterion was based on increasing specific ethanol yield (g ethanol g(-1) biomass) with acetic acid and furaldehyde tolerance. The screening showed that P. stipitis NRRL Y-7124 ACL 2-1RD (lacking cytochrome c), obtained using acrylamide, presented the highest specific ethanol production rate (1.82 g g(-1 )h(-1)). Meanwhile, the ACF8-3RD strain showed the highest acetic acid tolerance (7.80 g L(-1)) and the RHO2-3RD strain was able to tolerate up to 1.5 g L(-1) 2-furaldehyde with a growth and ethanol production inhibition of 23 and 22 %, respectively. The use of respiratory deficient yeast phenotype is a strategy for ethanol production improvement in a medium with toxic compounds such as hydrolysed sugarcane bagasse amongst others. PMID:24700134

Ortiz-Muñiz, B; Rasgado-Mellado, J; Solis-Pacheco, J; Nolasco-Hipólito, C; Domínguez-González, J M; Aguilar-Uscanga, M G

2014-10-01

326

Determination of critical conditions for the esterification of acetic acid with ethanol in the presence of carbon dioxide  

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Full Text Available In this work, we present the calculation of critical coordinates for the esterification of acetic acid with ethanol in compressed carbon dioxide. Determination of the critical pressure for this system is useful, since the conversion of this reaction increases with pressure in the two-phase region, reaching a maximum at the critical point. We used a calculation framework based on a coordinate transformation for molar fractions, producing a new compositional domain. For a system with five components (acetic acid + ethanol + ethyl acetate + water + carbon dioxide and one equilibrium reaction, the compositional domain is entirely described by three independent transformed coordinates. The results obtained were compared with experimental observations presented in the literature. The results illustrate the capability of the framework used to determine critical coordinates for reactive systems, and thus its usefulness as a tool for pressure tuning for this esterification reaction in compressed carbon dioxide.

G. M. Platt

2006-09-01

327

Calibration and intercomparison of acetic acid measurements using proton-transfer-reaction mass spectrometry (PTR-MS  

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Full Text Available Acetic acid is one of the most abundant organic acids in the ambient atmosphere, with maximum mixing ratios reaching into the tens of parts per billion by volume (ppbv range. The identities and associated magnitudes of the major sources and sinks for acetic acid are poorly characterized, due in part to the limitations of available measurement techniques. This paper demonstrates that, when properly calibrated, proton-transfer-reaction mass spectrometry (PTR-MS can be a valuable technique for fast response, accurate quantification of acetic acid in ambient air. Three different PTR-MS configurations were calibrated at low ppbv mixing ratios using permeation tubes, which yielded calibration factors between 7.0 and 10.9 normalized counts per second per ppbv (ncps ppbv?1 at a drift tube field strength of 132 Townsend (Td. Detection limits ranged from 0.06 to 0.32 ppbv with dwell times of 5 s. These calibration factors showed negligible humidity dependence. Acetic acid was measured with PTR-MS on Appledore B Island, ME, during the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT campaign and validated based on acetic acid measured in parallel using tandem mist chambers coupled with ion chromatography (MC/IC. Mixing ratios ranged from a minimum of 0.075 ± 0.004 ppbv to 3.555 ± 0.171 ppbv, with a median mixing ratio of 0.530 ± 0.025 ppbv. An orthogonal least squares linear regression of paired data yielded a slope of 1.14 ± 0.06 (2?, an intercept of 0.049 ± 0.020 (2? ppbv, and an R2 of 0.78.

K. B. Haase

2012-11-01

328

The Effect of Curcumin (Active Substance of Turmericon the Acetic Acid-Induced Visceral Nociception in Rats  

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Full Text Available In the present study, the effect of chronic oral administration of curcumin in the presence or absence of morphine and noloxone was investigated on the visceral nociception induced by acetic acid in rats. Intraperitoneal injection of acetic acid (1 mL, 2% produced contractions in the abdominal musculature (writhes. The latency time to the beginning of the first writhe was measured and the total number of writhes in the 1 h after acetic acid injection was counted. The latency time to the beginning of the first writhe was significantly (p<0.05 increased and the number of writhes was significantly (p<0.05 decreased by curcumin (20 and 40 mg kg-1 body weight. The same results were obtained after subcutaneous injection of morphine (1 mg kg-1 b.wt.. Naloxone at the dose of 1 mg kg-1 body weight had no effect on pain intensity. Curcumin significantly (p<0.05 enhanced the effect of morphine on the visceral pain responses, however did not reverse the effect of naloxone. Present data suggest that in the acetic acid-induced visceral nociception of rats, curcumin may produce an antinociceptive effect and the endogenous analgesic opioid system is involved in the curcumin-induced antinociception.

Hossein Tajik

2008-01-01

329

ETHANOL, ACETIC ACID, AND WATER ADSORPTION FROM BINARY AND TERNARY LIQUID MIXTURES ON HIGH-SILICA ZEOLITES  

Science.gov (United States)

Adsorption isotherms were measured for ethanol, acetic acid, and water adsorbed on high-silica ZSM-5 zeolite powder from binary and ternary liquid mixtures at room temperature. Ethanol and water adsorption on two high-silica ZSM-5 zeolites with different aluminum contents and a h...

330

Importance of the surrounding colonic mucosa in distinguishing between hyperplastic and adenomatous polyps during acetic acid chromoendoscopy  

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Full Text Available AIM: To examine the characteristics of colonic polyps, where it is difficult to distinguish adenomatous polyps from hyperplastic polyps, with the aid of acetic acid chromoendoscopy.METHODS: Acetic acid spray was applied to colonic polyps smaller than 10 mm before complete excision. Endoscopic images were taken before and 15-30 s after the acetic acid spray. Both pre- and post-sprayed images were shown to 16 examiners, who were asked to interpret the lesions as either hyperplastic or adenomatous polyps. Regression analysis was performed to determine which factors were most likely related to diagnostic accuracy.RESULTS: In 50 cases tested by the 16 examiners, the overall accuracy was 62.4% (499/800. Regression analysis demonstrated that surrounding colonic mucosa was the only factor that was significantly related to accuracy in discriminating adenomatous from hyperplastic polyps (P < 0.001. Accuracy was higher for polyps with linear surrounding colonic mucosa than for those with nodular surrounding colonic mucosa (P < 0.001, but was not related to the shape, location, or size of the polyp.CONCLUSION: The accuracy of predicting histology is significantly related to the pattern of colonic mucosa surrounding the polyp. Making a histological diagnosis of colon polyps merely by acetic acid spray is helpful for colon polyps with linear, regularly patterned surrounding colonic mucosa, and less so for those with nodular, irregularly patterned surrounding colonic mucosa.

Jeong Hwan Kim, Sun-Young Lee, Byung Kook Kim, Won Hyeok Choe, So Young Kwon, In-Kyung Sung, Hyung-Seok Park, Choon-Jo Jin

2008-03-01

331

Acetic acid promoted metal-free aerobic carbon-carbon bond forming reactions at ?-position of tertiary amines.  

Science.gov (United States)

The oxidative functionalization of the benzylic C-H bonds in tetrahydroisoquinolines and tetrahydro-?-carboline derivatives was investigated. C-C bond forming reactions proceeded with a range of nucleophiles (nitroalkane, enol silyl ether, indole, allylstannane, and tetrabutylammonium cyanide) under metal-free conditions and an oxygen atmosphere. Acetic acid caused a significant acceleration effect. PMID:25062493

Ueda, Hirofumi; Yoshida, Kei; Tokuyama, Hidetoshi

2014-08-15

332

Effect of Post-Harvest Acetic Acid and Plant Essential Oils on Shelf-Life Extension of Tomato Fruits  

International Nuclear Information System (INIS)

In vitro effect of different concentrations of acetic acid on linear growth of Alternaria alternate was studied. The causal agent of tomato black rots in contact and fumigation showed that acetic acid inhibit A. alternata growth at 2 ml/L and on 0.8 ml/L in contact and fumigation, respectively. In vivo effect showed that acetic acid at 6 ml/L reduced severity of infection of tomato fruits from 53.5% to 4.8% after 3 weeks of storage in dipping method but at the strongest fumigation methods, acetic acid inhibit tomato fruits rot at 0.4 ml/L after 3 weeks of storage. In vitro effect of camphore (Eucalyptus globulus Labill), caraway (Carium carvum L.) and peppermint oil (Mentha piperita L.) at different concentrations were tested against Alternaria alternata, since caraway oil is the strongest oil effect on fungal growth followed by peppermint and camphore respectively. Similarly in in vivo caraway oil inhibit tomato fruits rots at 6 ml/L followed by peppermint that inhibited tomato rots at 8 ml / L but camphore reduced tomato rots at 8 ml/L from 40% to 8.1%. Accepted April 2013

333

Modeling of the Thermodynamics of the Acetic Acid?Water Mixture Using the Cubic-Plus-Association Equation of State  

DEFF Research Database (Denmark)

The cubic-plus-association (CPA) equation of state is applied in this work to mixtures containing acetic acid and water. A previously developed modification of the model, the so-called CPA-Huron?Vidal (CPA-HV), is used. New CPA parameters have been estimated based on the vapor pressure, liquid density, enthalpy of vaporization, and vapor-phase compressibility factor data. The CPA-HV parameters have been fitted to, among others, experimental vapor compressibility factor data and experimental relative volatility data at different temperature ranges. The purpose of the work was to investigate whether the CPA-HV model can describe the vapor?liquid equilibrium for acetic acid?water over a temperature range of 200 K and at the same time represent the behavior of pure acetic acid and acetic acid?water mixtures with respect to enthalpies of vaporization and compressibility factors. It is shown that satisfactory results are overall obtained, but if an excellent match is needed over the whole temperature range, then different interaction parameters need to be used at the various temperature ranges.

Breil, Martin Peter; Kontogeorgis, Georgios

2011-01-01

334

Comparison of Visual Inspection with acetic acid and Pap smear in cervical cancer screening at a tertiary care hospital  

International Nuclear Information System (INIS)

th values of combined test were significantly higher than either of the two tests alone (p<0.01). Conclusion: Visual inspection with acetic acid has significantly higher sensitivity than Pap smear and may replace pap smear as a primary screening tool for universal screening. Combined test with higher predictive accuracy may be used for opportunistic screening. (author)

335

Synthesis and structural and vibrational analysis of (5,7-dichloro-quinolin-8-yloxy) acetic acid  

Science.gov (United States)

We have prepared the (5,7-dichloro-quinolin-8-yloxy) acetic acid and characterized it by infrared and Raman spectroscopies in the solid phase and by nuclear magnetic resonance (NMR) spectroscopy in a CDCl3 solution. The density functional theory (DFT) together with the 6-31G* and 6-311++G** basis sets were used to study its structure and vibrational properties. Two stable conformations of the compound were theoretically determined in the gas phase and probably these conformations are present in the solid phase. The harmonic vibrational wavenumbers for the optimized geometries were calculated at the same theory levels. For a complete assignment of all the observed bands in the vibrational spectra the DFT calculations were combined with Pulay's scaled quantum mechanical force field (SQMFF) methodology in order to fit the theoretical wavenumber values to the experimental ones. The force constants for the (5,7-dichloro-quinolin-8-yloxy) acetic acid were calculated and compared with those obtained for the (5-chloro-quinolin-8-yloxy) acetic acid and 2-(quinolin-8-yloxy)-acetic acid compounds. Furthermore, the characteristics of the electronic delocalization, the topological properties of the electronic charge density together with the highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) energy gaps were studied.

Romano, Elida; Castillo, María V.; Pergomet, Jorgelina L.; Zinczuk, Juan; Brandán, Silvia A.

2012-06-01

336

Production of acetic acid by hydrothermal two-step process of vegetable wastes for use as a road deicer  

Science.gov (United States)

This study aimed to produce acetic acid from vegetable wastes by a new hydrothermal two-step process. A continuous flow reaction system with a maximum treatment capacity of 2 kg/h of dry biomass developed by us was used. Five kinds of vegetables of carrots, white radish, chinese cabbage, cabbage and potato were selected as the representation of vegetable wastes. First, batch experiments with the selected vegetables were performed under the condition of 300°C, 1 min for the first step, and 300°C, 1 min and 70% oxygen supply for the second step, which is the optimum condition for producing acetic acid in the case of using starch as test material. The highest yields of acetic acid from five vegetables were almost the same as those obtained from starch. Subsequently, similar the highest yield of acetic acid and experimental conditions from vegetables were also obtained successfully using the continuous flow reaction system. These results should be useful for developing an industrial scale process.

Jin, F.; Watanabe, Y.; Kishita, A.; Enomoto, H.; Kishida, H.

2008-07-01

337

Root-uptake of 14C derived from acetic acid and 14C transfer to rice edible parts  

International Nuclear Information System (INIS)

plant in sand culture was considered to be decreased compared with that for the plant in the hydroponics experiment. It was suggested that rice plant absorbed and assimilated 14C through the plant roots not because of uptake of 14C-acetic acid but because of uptake of 14C in gaseous forms such as 14CO2.

338

Root-Uptake of C-14 Acetic Acid by Various Plants and C-14 Dynamics Surrounding the Experimental Tessera  

International Nuclear Information System (INIS)

sorbed by all the plants through their roots were considered to be very small. Inorganic carbon transformed from C-14 acetic acid would be taken up by plants through the roots, and some fraction of C-14 would be assimilated into the shoots by photosynthesis. (authors)

339

Mitochondrial degradation in acetic acid-induced yeast apoptosis: the role of Pep4 and the ADP/ATP carrier.  

Science.gov (United States)

We have previously shown that acetic acid activates a mitochondria-dependent death process in Saccharomyces cerevisiae and that the ADP/ATP carrier (AAC) is required for mitochondrial outer membrane permeabilization and cytochrome c release. Mitochondrial fragmentation and degradation have also been shown in response to this death stimulus. Herein, we show that autophagy is not active in cells undergoing acetic acid-induced apoptosis and is therefore not responsible for mitochondrial degradation. Furthermore, we found that the vacuolar protease Pep4p and the AAC proteins have a role in mitochondrial degradation using yeast genetic approaches. Depletion and overexpression of Pep4p, an orthologue of human cathepsin D, delays and enhances mitochondrial degradation respectively. Moreover, Pep4p is released from the vacuole into the cytosol in response to acetic acid treatment. AAC-deleted cells also show a decrease in mitochondrial degradation in response to acetic acid and are not defective in Pep4p release. Therefore, AAC proteins seem to affect mitochondrial degradation at a step subsequent to Pep4p release, possibly triggering degradation through their involvement in mitochondrial permeabilization. The finding that both mitochondrial AAC proteins and the vacuolar Pep4p interfere with mitochondrial degradation suggests a complex regulation and interplay between mitochondria and the vacuole in yeast programmed cell death. PMID:20345665

Pereira, Clara; Chaves, Susana; Alves, Sara; Salin, Bénédict; Camougrand, Nadine; Manon, Stéphen; Sousa, Maria João; Côrte-Real, Manuela

2010-06-01

340

Metal-organic coordination architectures of azole heterocycle ligands bearing acetic acid groups: Synthesis, structure and magnetic properties  

International Nuclear Information System (INIS)

Four new coordination complexes with azole heterocycle ligands bearing acetic acid groups, [Co(L1)2]n (1), [CuL1N3]n (2), [Cu(L2)2.0.5C2H5OH.H2O]n (3) and [Co(L2)2]n (4) (here, HL1=1H-imidazole-1-yl-acetic acid, HL2=1H-benzimidazole-1-yl-acetic acid) have been synthesized and structurally characterized. Single-crystal structure analysis shows that 3 and 4 are 2D complexes with 44-sql topologies, while another 2D complex 1 has a (43)2(46)-kgd topology. And 2 is a 3D complex composed dinuclear ?1,1-bridging azido CuII entities with distorted rutile topology. The magnetic properties of 1 and 2 have been studied. - Graphical Abstract: The synthesis, crystal structure, and magnetic properties of the new coordination complexes with azole heterocycle ligands bearing acetic acid groups are reported.

 
 
 
 
341

Estimation of normal chromium-51 ethylene diamine tetra-acetic acid clearance in children  

International Nuclear Information System (INIS)

In order to estimate the normal range of chromium-51 ethylene diamine tetra-acetic acid (EDTA) clearance in children, we selected a series of 256 patients with past or present urinary tract infection who showed, at the time of the clearance determination, normal technetium-99m dimercaptosuccinic acid (DMSA) scintigraphy and normal left to right DMSA relative uptake. The clearance was calculated by means of either the simplified second exponential method or the 120-min single blood sample; Chantler's correction was used in order to correct for having neglected the first exponential. There was a progressive increase in clearance from the first weeks of life (mean value around 1 month: 55 ml/min/1.73 m2), with a plateau at around 18 months. Between 2 and 17 years of age, the clearance values remained constant, with a mean value of 114 ml/min/1.73 m2 (SD: 24 ml/min); this is similar to the level described for inulin clearance. No significant differences were observed between boys and girls, or between clearance values calculated with one or with two blood samples. Taking into account the hour of intravenous injection of the tracer, we did not observe any influence of the lunchtime meal on the distribution of the 51Cr-EDTA clearance values. (orig.)

342

Estimation of normal chromium-51 ethylene diamine tetra-acetic acid clearance in children  

Energy Technology Data Exchange (ETDEWEB)

In order to estimate the normal range of chromium-51 ethylene diamine tetra-acetic acid (EDTA) clearance in children, we selected a series of 256 patients with past or present urinary tract infection who showed, at the time of the clearance determination, normal technetium-99m dimercaptosuccinic acid (DMSA) scintigraphy and normal left to right DMSA relative uptake. The clearance was calculated by means of either the simplified second exponential method or the 120-min single blood sample; Chantler's correction was used in order to correct for having neglected the first exponential. There was a progressive increase in clearance from the first weeks of life (mean value around 1 month: 55 ml/min/1.73 m[sup 2]), with a plateau at around 18 months. Between 2 and 17 years of age, the clearance values remained constant, with a mean value of 114 ml/min/1.73 m[sup 2] (SD: 24 ml/min); this is similar to the level described for inulin clearance. No significant differences were observed between boys and girls, or between clearance values calculated with one or with two blood samples. Taking into account the hour of intravenous injection of the tracer, we did not observe any influence of the lunchtime meal on the distribution of the [sup 51]Cr-EDTA clearance values. (orig.)

Piepsz, A. (Dept. of Radioisotopes, Academic Hospital, VUB Brussels (Belgium) Dept. of Radioisotopes, Hopital Saint-Pierre, Brussels (Belgium)); Pintelon, H. (Dept. of Radioisotopes, Academic Hospital, VUB Brussels (Belgium)); Ham, H.R. (Dept. of Radioisotopes, Hopital Saint-Pierre, Brussels (Belgium))

1994-01-01

343

Variation in indole-3-acetic acid transport and its relationship with growth in etiolated lupin hypocotyls.  

Science.gov (United States)

The relationship between the variation in polar auxin transport (PAT) and elongating growth in etiolated Lupinus albus hypocotyls was investigated. Parameters of auxin transport, such as the amount transported, intensity of the transport and sensitivity to 1-N-naphthylphthalamic acid (NPA) inhibition were measured in isolated sections from different sites (apical, middle and basal) along the hypocotyls in seedlings of different ages. Auxin transport was studied by applying radioactive indole-3-acetic acid (IAA) to upright and inverted sections. Basipetal transport was much higher than acropetal and very sensitive to NPA inhibition, which indicates that transport is polarized. Polarity was expressed as the NPA-induced inhibition and the basipetal/acropetal ratio. As a rule, both the amount of IAA transported and the polarity varied with the age of the seedlings, with values increasing from 3 to 5d and then decreasing. Both parameters were higher in apical (where most growth is localized) than in middle and basal regions, although this longitudinal gradient tended to disappear with aging as hypocotyl growth slowed and finally ceased. The application of NPA did not modify hypocotyl elongation in 5-d-old intact seedlings. Derooting of the seedlings drastically reduced elongation in the control, while NPA partially restored the growth, which suggests that NPA induces an increase in auxin in the elongation region. These results suggest that a basipetally decreasing gradient in PAT along the hypocotyl, which changes with age, may be responsible for auxin distribution pattern controlling growth. PMID:16904231

Nicolás, Juana Inés López; Acosta, Manuel; Sánchez-Bravo, José

2007-07-01

344

[Studies on the mode of action of indole-3-acetic acid by means of heavy water].  

Science.gov (United States)

The auxin-induced cell elongation and the formation of indoleacetyl-aspartic acid (IAAsp) of pea epicotyl sections and Agrostemma hypocotyl sections are inhibited by heavy water. The formation of IAAsp requires a specific enzyme. The lack of IAAsp in D2O-treated plant tissues may be due to an influence of D2O on the induction or on the synthesis of that enzyme. Treatment of plant sections with synthetic IAAsp has no effect on the growth of the sections in D2O. Indole-3-acetic acid (IAA) increases the incorporation of (32)P-orthophosphate into ribosomal and soluble RNA of pea epicotyl sections in H2O but not in D2O. The synthesis of ribosomal RNA is decreased by heavy water.The effects of IAA and D2O on the soluble proteins of pea sections have been studied by PAA-gel electrophoresis. D2O does not change the pattern of protein bands in comparison with the H2O-control, but prevents the probably IAA-induced alteration of the Rf-value of one protein band on the pherogram. It is assumed that the inhibition of auxin-induced reactions in the D2O-medium is due to the stabilizing effect of heavy water on allosteric proteins. The results of this work support the hypothesis that IAA acts as allosteric effector. PMID:24515821

Dahlhelm, H

1969-09-01

345

Nucleic acid bases in 1-alkyl-3-methylimidazolium acetate ionic liquids: A thermophysical and ionic conductivity analysis  

International Nuclear Information System (INIS)

Highlights: ? We report the effect of nucleic acid bases on the ionicity of 1,3-dialkylimidazolium acetate ILs. ? Thermophysical properties of the neat ILs were studied as a function of temperature. ? Effect of nucleobase content on the ILs conductivity, density and viscosity (298 K–343 K). ? Walden plots were determined and used to clarify the role of the nucleobases in the ILs ionicity. - Abstract: The use of ionic liquids as a media for dissolving DNA holds great promise for the development of new base materials in electrochemistry. This paper reports the systematic study of the effect of two nucleic acid bases, uracil and adenine, on the ionicity of 1-alkyl-3-methylimidazolium acetates achieved by monitoring several thermodynamic and transport properties. Density, dynamic viscosity, speed of sound, refractive index and ionic conductivity of 1-ethyl-3-methylimidazolium acetate and 1-butyl-3-methylimidazolium acetate were studied as a function of temperature at atmospheric pressure. The thermal expansion coefficients and molar volumes of these ionic liquids were calculated from the experimental density values. The various properties of the binary mixtures 1-ethyl-3-methylimidazolium acetate with uracil or adenine, namely, their ionic conductivity, density and viscosity in the temperature range 298 K–343 K were determined as a function of the nucleobase content. Walden plots were determined and used to clarify the role of the nucleobases in the ionic liquids ionicity.

346

Enhanced-effect of hypertonic saline, acetic acid and their mixture on hepatic radiofrequency ablation: an experimental study  

International Nuclear Information System (INIS)

Objective: To compare the effects of hypertonic saline, acetic acid and acetic acid- hypertonic saline (AAHS) solution on the ablated volume produced by hepatic radiofrequency ablation (RFA) in rabbits in vivo, and to determine the optimal synergist for radiofrequency ablation. Methods: Thirty big-ear white rabbits were equally divided into group A (RFA alone), group B (RFA with 36% NaCl injection), group C (RFA with 50% acetic acid injection), group D (RFA with 50% AAHS injection), group E (50% AAHS injection alone), and group F (36% NaC1 injection alone), with five rabbits in each group. Follow-up exam with CT scanning was made. The experimental rabbits were sacrificed by stages. The livers were collected and fixed in 10% formalin. Both the longitudinal and transverse diameter of the necrosis lesion produced by radiofrequency ablation were measured, the results were compared among groups. Results: The difference in the lowest impedance value between group A and other groups was statistically significant (P0.997). The persistent time of group A was significantly shorter than that of both group B and group D (P<0.05), while significant difference in persistent time existed between group C and group B or group D (P<0.05). The coagulation necrosis area in group B, C and D was significantly larger than that in group A (P<0.05). The transverse coagulation necrosis area of group D was the largest (P<0.05). Marked enhancement at the rim of coagulation necrosis lesions was observed on enhanced CT scans one week after the procedure. The coagulation necrosis lesions were obviously contracted three weeks after the treatment. Operation-related complications occurred in six rabbits (50%, 6/12). Peritoneal adhesion and ascites occurred in 4 rabbits receiving acetic acid (50%, 4/6) and in two rabbits not receiving acetic acid (33%, 2/ 6). Conclusions: Combination of RFA with 50% acetic acid-hypertonic saline injection can produce larger hepatic coagulation necrosis volume in experimental rabbits, the synergy of 50% acetic acid-hypertonic saline is superior to single pharmaceutical solution. (authors)

347

Root-uptake of {sup 14}C derived from acetic acid and {sup 14}C transfer to rice edible parts  

Energy Technology Data Exchange (ETDEWEB)

Three types of culture experiments using paddy rice (Oryza sativa L.) were performed to examine root-uptake of {sup 14}C in the form of acetic acid: double pot experiment (hydroponics), wet culture experiment (submerged sand medium), and chamber experiment (hydroponics and submerged sand medium). The {sup 14}C radioactivity in the plant, mediums, and atmospheric carbon dioxide ({sup 14}CO{sub 2}) in the chamber were determined, and the distribution of {sup 14}C in the plant was visualized using autoradiography. In the double pot experiment, the shoot of the plant and the lower root which was soaked in the culture solution had {sup 14}C radioactivity, but the upper root which did not have contact with the solution had none. There were also {sup 14}C radioactivity in the grains and roots in the wet culture experiment. Results of the chamber experiment showed that {sup 14}CO{sub 2} gas was released from the culture solution in both types of cultures. Results indicated that the {sup 14}C-acetic acid absorbed by rice plant through its root would be very small. Most of the {sup 14}C-acetic acid was transformed into gaseous forms either in the culture solution or rhizosphere. A relatively longer time would be needed to assimilate {sup 14}C derived from acetic acid to grain parts after it was once absorbed by the shoot through the root. Availability of {sup 14}C for the plant in sand culture was considered to be decreased compared with that for the plant in the hydroponics experiment. It was suggested that rice plant absorbed and assimilated {sup 14}C through the plant roots not because of uptake of {sup 14}C-acetic acid but because of uptake of {sup 14}C in gaseous forms such as {sup 14}CO{sub 2}.

Ogiyama, Shinichi [Office of Biospheric Assessment for Waste Disposal, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi 263-8555 (Japan)], E-mail: ogiyama@nirs.go.jp; Suzuki, Hiroyuki [Graduate School of Pharmaceutical Sciences, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba-shi 263-5522 (Japan); Inubushi, Kazuyuki [Graduate School of Horticulture, Chiba University, 648 Matsudo, Matsudo-shi 271-8510 (Japan); Takeda, Hiroshi; Uchida, Shigeo [Office of Biospheric Assessment for Waste Disposal, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi 263-8555 (Japan)

2010-02-15

348

Antibacterial Power of Sodium Hypochlorite Combined with Surfactants and Acetic Acid  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese O objetivo deste estudo foi verificar o poder antibacteriano do hipoclorito de sódio a 1% acrescido do ácido acético 1%, do NaOCl 5,25%, e de duas soluções irrigadoras modificadas com surfactantes, Hypoclean e Chlor-Xtra, em tubos de dentina bovina. Um total de 120 tubos de dentina preparados a part [...] ir de incisivos bovinos foram infectados durante 28 dias com o Enterococcus faecalis, e aleatoriamente divididos em seis grupos: NaOCl 5,25%; Hypoclean; Chlor-Xtra; NaOCl 1% com ácido acético 1%; tubos de dentina infectados (controle positivo); e tubos de dentina esterilizados (controle negativo). Em períodos de tempo de 0, 7, 14, 21 e 28 dias, raspas de dentina foram coletadas usando brocas esféricas com diâmetros crescentes, e mantidas em tubos de ensaio contendo 3 mL de infusão cérebro coração (brain heart infusion). A análise dos dados foi feita com testes paramétricos (ANOVA a um fator e teste de comparações múltiplas de Bonferroni, ?=1%). Após a cultura, o número de unidades formadoras de colônias (UFC) foi contado. Todas as soluções de hipoclorito de sódio mostraram pequena quantidade de UFC nos períodos por até 28 dias. Chlor Xtra e Hypoclean tiveram menor número de UFC em todos os períodos observados, com maior efetividade antimicrobiana do que o NaOCl 5,25% e do que o NaOCl a 1% com ácido acético a 1%. Abstract in english The aim of this ex vivo study was to compare the antibacterial power of 1% NaOCl with 1% acetic acid, 5.25% NaOCl and two commercially available NaOCl modified with surfactants in bovine root dentin. A total of 120 dentin tubes prepared from intact bovine incisors were infected for 21 days with Ente [...] rococcus faecalis and randomly divided into six groups as follows: 5.25%NaOCl; Hypoclean; Chlor-Xtra; 1% NaOCl with 1% acetic acid; infected dentin tubes (positive control); and sterile dentin tubes (negative control). At experimental times of 0, 7, 14, 21 and 28 days, dentin chips were collected using sequential round burs with increasing diameters in separate test tubes containing 3 mL of freshly prepared BHI. Statistical analysis were performed using parametric methods (one-way ANOVA, and Bonferroni's multiple comparisons test, ?=0.01). After culturing, the number of colony-forming units (CFU) was counted. All the NaOCl solutions showed small number of CFU over 28 days. ChlorXtra and Hypoclean had the smallest number of CFU at all times with greater antimicrobial efficacy than 5.25% NaOCl and 1% NaOCl solution with 1% acetic acid.

Luciano, Giardino; Carlos, Estrela; Zahed, Mohammadi; Flavio, Palazzi.

349

Improvement of sensitivity of electrolyte cathode discharge atomic emission spectrometry (ELCAD-AES) for mercury using acetic acid medium.  

Science.gov (United States)

A method has been developed to improve the sensitivity of the electrolyte cathode discharge atomic emission spectrometry (ELCAD-AES) for mercury determination. Effects of various low molecular weight organic solvents at different volume percentages as well as at different acid molarities on the mercury signal were investigated using ELCAD-AES. The addition of few percent of organic solvent, acetic acid produced significant enhancement in mercury signal. Acetic acid of 5% (v/v) with the 0.2M acidity has been found to give 500% enhancement for mercury signal in flow injection mode. Under the optimized parameters the repeatability, expressed as the percentage relative standard deviation of spectral peak area for mercury with 5% acetic acid was found to be 10% for acid blank solution and 5% for 20 ng/mL mercury standard based on multiple measurements with a multiple sample loading in flow injection mode. Limit of detection of this method was determined to be 2 ng/mL for inorganic mercury. The proposed method has been validated by determining mercury in certified reference materials, Tuna fish (IAEA-350) and Aquatic plant (BCR-060). Accuracy of the method for the mercury determination in the reference materials has been found to be between 3.5% and 5.9%. This study enhances the utility of ELCAD-AES for various types of biological and environmental materials to quantify total mercury at very low levels. PMID:22483872

Shekhar, R

2012-05-15

350

Acetic acid increases the phage-encoded enterotoxin A expression in Staphylococcus aureus  

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Full Text Available Abstract Background The effects of acetic acid, a common food preservative, on the bacteriophage-encoded enterotoxin A (SEA expression and production in Staphylococcus aureus was investigated in pH-controlled batch cultures carried out at pH 7.0, 6.5, 6.0, 5.5, 5.0, and 4.5. Also, genomic analysis of S. aureus strains carrying sea was performed to map differences within the gene and in the temperate phage carrying sea. Results The sea expression profile was similar from pH 7.0 to 5.5, with the relative expression peaking in the transition between exponential and stationary growth phase and falling during stationary phase. The levels of sea mRNA were below the detection limit at pH 5.0 and 4.5, confirmed by very low SEA levels at these pH values. The level of relative sea expression at pH 6.0 and 5.5 were nine and four times higher, respectively, in the transitional phase than in the exponential growth phase, compared to pH 7.0 and pH 6.5, where only a slight increase in relative expression in the transitional phase was observed. Furthermore, the increase in sea expression levels at pH 6.0 and 5.5 were observed to be linked to increased intracellular sea gene copy numbers and extracellular sea-containing phage copy numbers. The extracellular SEA levels increased over time, with highest levels produced at pH 6.0 in the four growth phases investigated. Using mitomycin C, it was verified that SEA was at least partially produced as a consequence of prophage induction of the sea-phage in the three S. aureus strains tested. Finally, genetic analysis of six S. aureus strains carrying the sea gene showed specific sea phage-groups and two versions of the sea gene that may explain the different sea expression and production levels observed in this study. Conclusions Our findings suggest that the increased sea expression in S. aureus caused by acetic acid induced the sea-encoding prophage, linking SEA production to the lifecycle of the phage.

da Silva Ayla

2010-05-01

351

A 9-vinyladenine-based molecularly imprinted polymeric membrane for the efficient recognition of plant hormone {sup 1}H-indole-3-acetic acid  

Energy Technology Data Exchange (ETDEWEB)

9-Vinyladenine was synthesized as a novel functional monomer for molecular imprinting techniques and its structure was established with elemental analysis and {sup 1}H NMR spectroscopy. The binding mechanism between this functional monomer 9-vinyladenine and the plant hormone {sup 1}H-indole-3-acetic acid in acetonitrile was studied with UV-vis spectrophotometry. Based on this study, using {sup 1}H-indole-3-acetic acid as a template molecule, a specific 9-vinyladenine-based molecularly imprinted polymeric membrane was prepared. Then, the resultant polymeric membrane morphologies were visualized with scanning electron microscopy, and the membrane permselectivity for {sup 1}H-indole-3-acetic acid, {sup 1}H-indole-3-butyric acid and kinetin was tested with separate experiments and competitive diffusion experiments. These results showed that the imprinted polymeric membrane prepared with 9-vinyladenine exhibited higher transport selectivity for the template molecule {sup 1}H-indole-3-acetic acid than {sup 1}H-indole-3-butyric acid or kinetin. The membrane prepared with 9-vinyladenine also took on higher permselectivity for {sup 1}H-indole-3-acetic acid in comparison with the imprinted membrane made with methacrylic acid. It is predicted that the 9-vinyladenine-based molecularly imprinted membrane may be applicable to the assay of {sup 1}H-indole-3-acetic acid or for the preparation of a molecularly imprinted polymer sensor for the analysis of {sup 1}H-indole-3-acetic acid in plant samples.

Chen Changbao [College of Chemistry and Material Science, Shandong Agricultural University, Taian, Shandong 271018 (China); Chen Yanjun [College of Chemistry and Material Science, Shandong Agricultural University, Taian, Shandong 271018 (China); Zhou Jie [College of Chemistry and Material Science, Shandong Agricultural University, Taian, Shandong 271018 (China)]. E-mail: zhoujie@sdau.edu.cn; Wu Chunhui [College of Chemistry and Material Science, Shandong Agricultural University, Taian, Shandong 271018 (China)

2006-05-31

352

Effects of Radiation-Induced Crosslinking on the Thermal Stability of Poly Lactic Acid and Cellulose Acetate Blends  

International Nuclear Information System (INIS)

Full text: Polylactic acid (PLA) was blended with cellulose acetate to improve the thermal stability of PLA, while simultaneously retaining the inherent compost ability of both polymers. The blends were irradiated by an electron beam accelerator, both with and without triallyl isocyanurate (TAIC) as a crosslinking agent. Results from gel fraction and differential scanning calorimeter (DSC) showed that blends with TAIC were able to undergo crosslinking reactions induced by radiation, whereas results from thermo mechanical analyzer (TMA) showed that the presence of cellulose acetate improved the thermal stability of PLA

353

Transport of the two natural auxins, indole-3-butyric acid and indole-3-acetic acid, in Arabidopsis  

Science.gov (United States)

Polar transport of the natural auxin indole-3-acetic acid (IAA) is important in a number of plant developmental processes. However, few studies have investigated the polar transport of other endogenous auxins, such as indole-3-butyric acid (IBA), in Arabidopsis. This study details the similarities and differences between IBA and IAA transport in several tissues of Arabidopsis. In the inflorescence axis, no significant IBA movement was detected, whereas IAA is transported in a basipetal direction from the meristem tip. In young seedlings, both IBA and IAA were transported only in a basipetal direction in the hypocotyl. In roots, both auxins moved in two distinct polarities and in specific tissues. The kinetics of IBA and IAA transport appear similar, with transport rates of 8 to 10 mm per hour. In addition, IBA transport, like IAA transport, is saturable at high concentrations of auxin, suggesting that IBA transport is protein mediated. Interestingly, IAA efflux inhibitors and mutations in genes encoding putative IAA transport proteins reduce IAA transport but do not alter IBA movement, suggesting that different auxin transport protein complexes are likely to mediate IBA and IAA transport. Finally, the physiological effects of IBA and IAA on hypocotyl elongation under several light conditions were examined and analyzed in the context of the differences in IBA and IAA transport. Together, these results present a detailed picture of IBA transport and provide the basis for a better understanding of the transport of these two endogenous auxins.

Rashotte, Aaron M.; Poupart, Julie; Waddell, Candace S.; Muday, Gloria K.; Brown, C. S. (Principal Investigator)

2003-01-01

354

Studies on the growth and indole-3-acetic acid and abscisic acid content of Zea mays seedlings grown in microgravity  

Science.gov (United States)

Measurements were made of the fresh weight, dry weight, dry weight-fresh weight ratio, free and conjugated indole-3-acetic acid, and free and conjugated abscisic acid in seedlings of Zea mays grown in darkness in microgravity and on earth. Imbibition of the dry kernels was 17 h prior to launch. Growth was for 5 d at ambient orbiter temperature and at a chronic accelerational force of the order of 3 x 10(-5) times earth gravity. Weights and hormone content of the microgravity seedlings were, with minor exceptions, not statistically different from seedlings grown in normal gravity. The tissues of the shuttle-grown plants appeared normal and the seedlings differed only in the lack of orientation of roots and shoots. These findings, based upon 5 d of growth in microgravity, cannot be extrapolated to growth in microgravity for weeks, months, and years, as might occur on a space station. Nonetheless, it is encouraging, for prospects of bioregeneration of the atmosphere and food production in a space station, that no pronounced differences in the parameters measured were apparent during the 5 d of plant seedling growth in microgravity.

Schulze, A.; Jensen, P. J.; Desrosiers, M.; Buta, J. G.; Bandurski, R. S.

1992-01-01

355

Effect of Gibberellic Acid, Kinetin and Indole 3-Acetic Acid on Seed Germination Performance of Dianthus caryophyllus (Carnation  

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Full Text Available The experiment was undertaken with an objective to investigate the effect of various concentrations of plant growth regulators, i.e., Gibberellic acid (GA3, Kinetin and Indole 3-acetic acid (IAA on seed germination of Dianthus caryophyllus. Dianthus seeds were soaked in different concentrations (0 ppm or control, 10 ppm, 20 ppm, 30 ppm and 40 ppm of each of GA3, Kinetin and IAA for 24 h at room temperature (25±2oC. Three replicates of each treatment with ten seeds per replicate were arranged for precise physiological analysis. Significant variation was found in all aspects after analysis of variance (ANOVA of each mean value. After two weeks of seed soaking, it was noted that germination percentages were significantly accelerated by lower concentrations (10 and 20 ppm of used hormones. Amongst the three potential growth regulators, 20 ppm was found most effective because it showed highest germination percentage for GA3 (87.46%, Kinetin (78.92% and IAA (75.35%. A great deal of information relating to seed germination practices shows that these plant growth regulators were efficient in overcoming dormancy leading to rapid seed germination. GA3 was selected as best hormone in this study, which showed highest seed germination (87.46%. These results could be useful in large scale cultivation of Dianthus caryophyllus plants to improve its floricultural impact worldwide.

Rajib Roychowdhury

2012-10-01

356

Microscopic diagnosis of sodium acetate-acetic acid-formalin-fixed stool samples for helminths and intestinal protozoa: a comparison among European reference laboratories.  

Science.gov (United States)

The present study aimed to compare the diagnostic performance of different European reference laboratories in diagnosing helminths and intestinal protozoa, using an ether-concentration method applied to sodium acetate-acetic acid-formalin (SAF)-preserved faecal samples. In total, 102 stool specimens were analysed during a cross-sectional parasitological survey in urban farming communities in Côte d'Ivoire. Five SAF-preserved faecal samples were prepared from each specimen and forwarded to the participating reference laboratories, processed and examined under a microscope adhering to a standard operating procedure (SOP). Schistosoma mansoni (cumulative prevalence: 51.0%) and hookworm (cumulative prevalence: 39.2%) were the predominant helminths. There was excellent agreement (kappa > 0.8; p hominis (median prevalence: 55.9%) and Entamoeba histolytica/Entamoeba dispar (median prevalence: 47.1%). Substantial agreement among reference laboratories was found for E. coli (kappa = 0.69), but only fair or moderate agreement was found for other Entamoeba species, Giardia intestinalis and Chilomastix mesnili. There was only poor agreement for B. hominis, Isospora belli and Trichomonas intestinalis. In conclusion, although common helminths were reliably diagnosed by European reference laboratories, there was only moderate agreement between centres for pathogenic intestinal protozoa. Continued external quality assessment and the establishment of a formal network of reference laboratories is necessary to further enhance both accuracy and uniformity in parasite diagnosis. PMID:19456836

Utzinger, J; Botero-Kleiven, S; Castelli, F; Chiodini, P L; Edwards, H; Köhler, N; Gulletta, M; Lebbad, M; Manser, M; Matthys, B; N'Goran, E K; Tannich, E; Vounatsou, P; Marti, H

2010-03-01

357

Impact of trace element addition on degradation efficiency of volatile fatty acids, oleic acid and phenyl acetate and on microbial populations in a biogas digester.  

Science.gov (United States)

The effect of trace element addition on anaerobic digestion of food industry- and household waste was studied using two semi-continuous lab-scale reactors, one (R30+) was supplied with Fe, Co and Ni, while the other (R30) acted as a control. Tracer analysis illustrated that methane production from acetate proceeded through syntrophic acetate oxidation (SAO) in both digesters. The effect of the trace elements was also evaluated in batch assays to determine the capacity of the microorganisms of the two digesters to degrade acetate, phenyl acetate, oleic acid or propionate, butyrate and valerate provided as a cocktail. The trace elements addition improved the performance of the process giving higher methane yields during start-up and early operation and lower levels of mainly acetate and propionate in the R30+ reactor. The batch assay showed that material from R30+ gave effects on methane production from all substrates tested. Phenyl acetate was observed to inhibit methane formation in the R30 but not in the R30+ assay. A real-time PCR analysis targeting methanogens on the order level as well as three SAO bacteria showed an increase in Methanosarcinales in the R30+ reactor over time, even though SAO continuously was the dominating pathway for methane production. Possibly, this increase explains the low VFA-levels and higher degradation rates observed in the R30+ batch incubations. These results show that the added trace elements affected the ability of the microflora to degrade VFAs as well as oleic acid and phenyl acetate in a community, where acetate utilization is dominated by SAO. PMID:22683024

Karlsson, Anna; Einarsson, Peter; Schnürer, Anna; Sundberg, Carina; Ejlertsson, Jörgen; Svensson, Bo H

2012-10-01

358

??????????????????? Synthesis of Acidic Ionic Liquids and Catalysts Application of Benzaldehyde Acetal  

Directory of Open Access Journals (Sweden)

Full Text Available  

??????N-???????????3?????????????????????????????????????????????????????????N-????-N(??????-????????????????????????????????????????????????????????????????????????????2.8%?????2 h?????125???????????????88.59%?????????4????????????

Three novel ionic liquids were synthesized using benzyl chloride, N-ethyl imidazole and pyridine as raw materials, the structure of these products were charactered, and these materials were applied to catalytic synthesis of benzaldehyde acetal. Compared with the traditional catalyst, the N-ethyl imidazole-N (p-sulfo benzalhydantoin-chloride imidazole salt ionic liquids have good catalytic activity. The synthesis reaction of benzaldehyde acetal catalyzed by the acidic ionic liquid was studied. The result shows that the yield of benzaldehyde acetal was 88.59% under the following conditions: Molar percentage of catalyst relative to the reactants 2.8%, reaction temperature 125?C and reaction time 2 h. The catalytic activity maintains stable even the acidic ionic liquid was used 4 times.

???

2012-07-01

359

Removal of iodine species by concentrated nitric acid, (2)  

International Nuclear Information System (INIS)

One of the most effective removing processes of iodine species is what is called ''Iodox Process'', which contains oxidation and absorption of iodine species by highly concentrated nitric acid. The result of fundamental test with bubble column in this process had been reported. Present paper describes the fundamental experiment by the use of packed column. This experiment has been carried out to clear the effect of feed gas flow rate, nitric acid flow rate, nitric acid concentration, and methyl iodide concentration on removal efficiency of methyl iodide. The following results were obtained. The decontamination factor of methyl iodide (DF) increases exponentially with nitric acid concentration, which agrees with the result obtained by using the bubble column. The factor is in inverse proportion to feed gas flow rate, and is also almost independent of nitric acid flow rate and methyl iodide concentration. The relation between the decontamination factor and the capacity coefficient has been examined, and then the experimental equations of the capacity coefficient and the decontamination factor on this fundamental experiment have been estimated. (author)

360

Biodiversity of yeasts, lactic acid bacteria and acetic acid bacteria in the fermentation of "Shanxi aged vinegar", a traditional Chinese vinegar.  

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Shanxi aged vinegar is a famous traditional Chinese vinegar made from several kinds of cereal by spontaneous solid-state fermentation techniques. In order to get a comprehensive understanding of culturable microorganism's diversity present in its fermentation, the indigenous microorganisms including 47 yeast isolates, 28 lactic acid bacteria isolates and 58 acetic acid bacteria isolates were recovered in different fermenting time and characterized based on a combination of phenotypic and genotypic approaches including inter-delta/PCR, PCR-RFLP, ERIC/PCR analysis, as well as 16S rRNA and 26S rRNA partial gene sequencing. In the alcoholic fermentation, the dominant yeast species Saccharomyces (S.) cerevisiae (96%) exhibited low phenotypic and genotypic diversity among the isolates, while Lactobacillus (Lb.) fermentum together with Lb. plantarum, Lb. buchneri, Lb. casei, Pediococcus (P.) acidilactici, P. pentosaceus and Weissella confusa were predominated in the bacterial population at the same stage. Acetobacter (A.) pasteurianus showing great variety both in genotypic and phenotypic tests was the dominant species (76%) in the acetic acid fermentation stage, while the other acetic acid bacteria species including A. senegalensis, A. indonesiensis, A. malorum and A. orientalis, as well as Gluconobacter (G.) oxydans were detected at initial point of alcoholic and acetic acid fermentation stage respectively. PMID:22265314

Wu, Jia Jia; Ma, Ying Kun; Zhang, Fen Fen; Chen, Fu Sheng

2012-05-01

 
 
 
 
361

Protective and therapeutic effects of resveratrol on acetic acid-induced gastric ulcer.  

Science.gov (United States)

Sprague Dawley rats of both sexes were injected with either saline or RVT (10 mg/kg) either before or after acetic acid ulcer induction and decapitated 3, 5 or 10 days after ulcer. In the saline-treated ulcer groups, macroscopically evident ulcers were observed, while RVT-pretreated or RVT-treated groups had lower macroscopic ulcer scores. Likewise, the microscopic damage scores were lower for the RVT-administered groups. Gastric myeloperoxidase activity, malondialdehyde, collagen and tumour necrosis factor-alpha levels, as well as luminol- and lucigenin-enhanced chemiluminescence levels that were elevated in the saline-administered ulcer groups, were depressed with both RVT-pretreatment and RVT-treatment. Moreover, depleted glutathione levels in the ulcer groups were increased back to control levels by both pre- and post-treatments of RVT. Results demonstrate that resveratrol has both protective and therapeutic effects on oxidative gastric damage by suppressing pro-inflammatory cascades, including the activation of pro-inflammatory cytokines, accumulation of neutrophils and release of oxygen-derived free radicals. PMID:19479585

Solmaz, Ali; Sener, Göksel; Cetinel, Sule; Yüksel, Meral; Ye?en, Cumhur; Ye?en, Berrak C

2009-06-01

362

Standardization of DNA Extraction from Methanol Acetic Acid Fixed Cytogenetic Cells of Cattle and Buffalo  

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Full Text Available The aim of the study is to standardize the simple method for extracting DNA from cells fixed in fixative (3:1 ratio of methanol and acetic acid glacial mostly used for chromosomal studies in cattle and buffaloes. These fixed cells were stored for more than 6 months at refrigerated temperature. The fixed cells were washed 2-3 times by the ice cold 1x Phosphate Buffer Saline (PBS with pH 7.4, so that effect of fixative may be eliminated. The genomic DNA was extracted by adding cell lysis and nucleus lysis buffers. The quality and quantity of DNA were estimated. The readings of nano drop and agarose gel electrophoresis indicate good quality DNA isolated with a rapid and simple protocol routinely using in our laboratory. The method enables us to study the DNA of a cattle and buffaloes after completing cytogenetic investigation or in cases where DNA samples are otherwise not available. This protocol may be useful for molecular analysis of DNA from fixed cells palettes.

Sanghamitra Katragadda

2013-01-01

363

Strain typing of acetic acid bacteria responsible for vinegar production by the submerged elaboration method.  

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Strain typing of 103 acetic acid bacteria isolates from vinegars elaborated by the submerged method from ciders, wines and spirit ethanol, was carried on in this study. Two different molecular methods were utilised: pulsed field gel electrophoresis (PFGE) of total DNA digests with a number of restriction enzymes, and enterobacterial repetitive intergenic consensus (ERIC) - PCR analysis. The comparative study of both methods showed that restriction fragment PFGE of SpeI digests of total DNA was a suitable method for strain typing and for determining which strains were present in vinegar fermentations. Results showed that strains of the species Gluconacetobacter europaeus were the most frequent leader strains of fermentations by the submerged method in the studied vinegars, and among them strain R1 was the predominant one. Results showed as well that mixed populations (at least two different strains) occurred in vinegars from cider and wine, whereas unique strains were found in spirit vinegars, which offered the most stressing conditions for bacterial growth. PMID:20832673

Fernández-Pérez, Rocío; Torres, Carmen; Sanz, Susana; Ruiz-Larrea, Fernanda

2010-12-01

364

VUV absorption spectrum of acetic acid between 6 and 20 eV  

International Nuclear Information System (INIS)

Absorption spectra of acetic acid were measured between 6 and 20 eV at a resolution of 8 meV. Previous measurements had a spectral limit of 11.7 eV. Analysis and band assignment were aided by data from theoretical calculations on valence states and from photoelectron spectroscopy. Valence transitions and nsa' 3COOH+, as well as transitions converging to the first excited state of the ion are discussed and assigned in the spectral region below 12 eV. Our assignments of valence transitions differ in many aspects from those of previous studies. Most of the Rydberg bands have never previously been assigned. Observation, analysis and possible assignments of absorption features between 12 and 20 eV were carried out for the first time. Rydberg bands converging to the higher ionization limits merge to form broad absorption features. Some absorption features in the 14-17 eV region are assigned to two types of valence ?*(C-H) <- ? transitions

365

A diverse assemblage of indole-3-acetic acid producing bacteria associate with unicellular green algae.  

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Microalgae have tremendous potential as a renewable feedstock for the production of liquid transportation fuels. In natural waters, the importance of physical associations and biochemical interactions between microalgae and bacteria is generally well appreciated, but the significance of these interactions to algal biofuels production have not been investigated. Here, we provide a preliminary report on the frequency of co-occurrence between indole-3-acetic acid (IAA)-producing bacteria and green algae in natural and engineered ecosystems. Growth experiments with unicellular algae, Chlorella and Scenedesmus, revealed IAA concentration-dependent responses in chlorophyll content and dry weight. Importantly, discrete concentrations of IAA resulted in cell culture synchronization, suggesting that biochemical priming of cellular metabolism could vastly improve the reliability of high density cultivation. Bacterial interactions may have an important influence on algal growth and development; thus, the preservation or engineered construction of the algal-bacterial assembly could serve as a control point for achieving low input, reliable production of algal biofuels. PMID:24879600

Bagwell, Christopher E; Piskorska, Magdalena; Soule, Tanya; Petelos, Angela; Yeager, Chris M

2014-08-01

366

High-performance radioimmunoassay for 5-hydroxy indole acetic acid (5HIAA)  

International Nuclear Information System (INIS)

A highly specific and sensitive radioimmunoassay for the main metabolite of serotonine, 5-hydroxy indole acetic acid (5HIAA) was developed. Iodination of the analogue was performed either by coupling 5HIAA to 125I-glycyl-tyrosine without any contact between 5HIAA and oxidation reagents or after protection of the 5-hydroxyl group by acetylation. The immunogen was synthesized by coupling first glycine to the epsilon-lysine residues of bovine serum albumin and then 5HIAA to glycine. Twenty-seven moles of 5HIAA were thus coupled. Antibodies raised in rabbits could be diluted up to 1/300,000. As expected this new class of antibodies exhibited a much greater affinity for 5HIAA-glycinamide than for 5HIAA. The chemical conversion of 5HIAA from biological samples into 5HIAA glycinamide lead to a very high specificity, demonstrated by competition experiments with 22 analogues, and to a sensitivity threshold below 5 pg exemplified by measurement of 5HIAA content in different areas of the mouse brain. (author)

367

Indole-3-acetic acid production by endophytic Streptomyces sp. En-1 isolated from medicinal plants.  

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Plant-associated actinobacteria are rich sources of bioactive compounds including indole-derived molecules such as phytohormone indole-3-acetic acid (IAA). In view of few investigations concerning the biosynthesis of IAA by endophytic actinobacteria, this study evaluated the potential of IAA production in endophytic streptomycete isolates sourced from medicinal plant species Taxus chinensis and Artemisia annua. By HPLC analysis of IAA combined with molecular screening approach of iaaM, a genetic determinant of streptomycete IAA synthesis via indole-3-acetamide (IAM), our data showed the putative operation of IAM-mediated IAA biosynthesis in Streptomyces sp. En-1 endophytic to Taxus chinensis. Furthermore, using the co-cultivation system of model plant Arabidopsis thaliana and streptomycete, En-1 was found to be colonized intercellularly in the tissues of Arabidopsis, an alternative host, and the effects of endophytic En-1 inoculation on the model plant were also assayed. The phytostimulatory effects of En-1 inoculation suggest that IAA-producing Streptomyces sp. En-1 of endophytic origin could be a promising candidate for utilization in growth improvement of plants of economic and agricultural value. PMID:23512121

Lin, Lan; Xu, Xudong

2013-08-01

368

The effects of indole-3-acetic acid on human and horse serum butyrylcholinesterase.  

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Butyrylcholinesterase (BChE) constitutes the first line defense in the serum of higher organisms and is a marker for toxic exposure. Indole-3-acetic acid (IAA) is a major plant growth hormone of the auxin class, affecting cell enlargement, and differentiation. As a result of the industrial usage, this agrochemical is consumed by non-target organisms. In this study, the interaction of IAA with purified human and horse serum BChEs were investigated. Both BChE species displayed biphasic hill plots using butyrylthiocholine as substrate. IAA interaction with BChE species was stable and concentration dependent. IAA was found to be linear-mixed type inhibitor for human serum BChE, and alpha and the Ki values were 2.15 +/- 1.09 mM and 3.09 +/- 0.95 mM, respectively. With horse enzyme IAA displayed uncompetitive inhibition with the Ki value of 1.05 +/- 0.09 mM. Acquisition of large amounts of IAA is unlikely but it can be taken as a basis for future inhibitor designs. PMID:16429500

Bodur, Ebru; Cokugras, A Nese

2005-12-15

369

Endohyphal bacterium enhances production of indole-3-acetic acid by a foliar fungal endophyte.  

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Numerous plant pathogens, rhizosphere symbionts, and endophytic bacteria and yeasts produce the important phytohormone indole-3-acetic acid (IAA), often with profound effects on host plants. However, to date IAA production has not been documented among foliar endophytes -- the diverse guild of primarily filamentous Ascomycota that live within healthy, above-ground tissues of all plant species studied thus far. Recently bacteria that live within hyphae of endophytes (endohyphal bacteria) have been detected, but their effects have not been studied previously. Here we show not only that IAA is produced in vitro by a foliar endophyte (here identified as Pestalotiopsis aff. neglecta, Xylariales), but that IAA production is enhanced significantly when the endophyte hosts an endohyphal bacterium (here identified as Luteibacter sp., Xanthomonadales). Both the endophyte and the endophyte/bacterium complex appear to rely on an L-tryptophan dependent pathway for IAA synthesis. The bacterium can be isolated from the fungus when the symbiotic complex is cultivated at 36°C. In pure culture the bacterium does not produce IAA. Culture filtrate from the endophyte-bacterium complex significantly enhances growth of tomato in vitro relative to controls and to filtrate from the endophyte alone. Together these results speak to a facultative symbiosis between an endophyte and endohyphal bacterium that strongly influences IAA production, providing a new framework in which to explore endophyte-plant interactions. PMID:24086270

Hoffman, Michele T; Gunatilaka, Malkanthi K; Wijeratne, Kithsiri; Gunatilaka, Leslie; Arnold, A Elizabeth

2013-01-01

370

Influence of Subcutaneous Indole-3-Acetic Acid Administration in Metabolism and Function of the Rat Leukocyte  

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Full Text Available Indole-3-Acetic Acid (IAA is a naturally occurring auxin, well known for its regulatory function in plant growth and its association with fruit ripening and senescence. This study aimed to investigate the effect of IAA administration on leukocytes metabolism and function. This growth plant hormone promoted a decrease in glucose oxidation (20% by neutrophils and an increase in glutamine consumption (31% by these cells, but no alteration was shown on consumption of the glucose and glutamine by lymphocytes. IAA did not cause a marked effect on the key enzyme activities of glucose and glutamine metabolism in neutrophils or lymphocytes. The IAA treatment did not show alteration of the phagocytic parameters of Staphyloccocus aureus engulment by neutrophils, with bacteria killed by myeloperoxidase activity in these cells, compared with the control animals. The observations presented led us to conclude that administration of subcutaneous IAA promotes an alteration in the rat`s neutrophil metabolism, deduced by a decrease in glucose consumption and an increase in glutamine consumption in neutrophils; suggesting that the alteration of glucose metabolism could be compensated for by glutamine utilization in these cells. The metabolism alteration in rat neutrophils does not reduces the phagocytic capacity or myeloperoxidase activity of this cell. The effect of IAA administration, similar to in vitro studies, may reflect the reaction between IAA and myeloperoxidase.

2007-01-01

371

Cyclic calcination/carbonation looping of dolomite modified with acetic acid for CO2 capture  

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The dolomite modified with acetic acid solution was proposed as a CO2 sorbent for calcination/carbonation cycles. The carbonation conversions for modified and original dolomites in a twin fixed-bed reactor system with increasing the numbers of cycles were investigated. The carbonation temperature in the range of 630 C-700 C is beneficial to the carbonation reaction of modified dolomite. The carbonation conversion for modified dolomite is significantly higher than that for original sorbent at the same reaction conditions with increasing numbers of reaction cycles. The modified dolomite exhibits a carbonation conversion of 0.6 after 20 cycles, while the unmodified sorbent shows a conversion of 0.26 at the same reaction conditions, which is calcined at 920 C and carbonated at 650 C. At the high calcination temperature over 920 C modified dolomite can maintain much higher conversion than unmodified sorbent. The mean grain size of CaO derived from modified dolomite is smaller than that from original sorbent with increasing numbers of reaction cycles. The calcined modified dolomite possesses greater surface area and pore volume than calcined original sorbent during the multiple cycles. The pore volume and pore area distributions for calcined modified dolomite are also superior to those for calcined unmodified sorbent during the looping cycle. The modified dolomite is proved as a new and promising type of regenerable CO2 sorbent for industrial applications. (author)

372

Inactivation of Listeria monocytogenes on frankfurters by monocaprylin alone or in combination with acetic acid.  

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The antilisterial activity of monocaprylin (MC) and its combination with acetic acid (AA) on frankfurters was investigated. Each frankfurter was surface inoculated with a three-strain mixture of Listeria monocytogenes to obtain an inoculation level of 4.0 log CFU per frankfurter, and then dipped for 35 s in sterile deionized water (45 or 50 degrees C) containing 1% ethanol (control), 50 mM MC plus 1% ethanol, 1% AA plus 1% ethanol, or 50 mM MC plus 1% AA plus 1% ethanol. Samples were vacuum packaged, stored at 4 degrees C for 77 days, and analyzed for L. monocytogenes. Sensory odor and color of frankfurters were evaluated using a 9-point hedonic scale. Color was also objectively measured using the Minolta Chroma Meter. From day 0 to day 77, population counts of L. monocytogenes on frankfurters dipped in antimicrobial solutions at 50 degrees C were consistently lower than the control counts. Similar results were observed for samples treated at 45 degrees C. However, L. monocytogenes grew readily on control samples at both temperatures. Dipping of frankfurters in antimicrobial solutions (45 or 50 degrees C) significantly reduced (P 0.05). Overall, results indicated that dipping of frankfurters with MC reduced L. monocytogenes, and inclusion of AA further enhanced MC antilisterial activity, without any negative effect on odor or color. PMID:17685330

Garcia, Marilyn; Amalaradjou, Mary Anne Roshni; Nair, Manoj Kumar Mohan; Annamalai, Thirunavukkarasu; Surendranath, Suman; Lee, Seok; Hoagland, Thomas; Dzurec, David; Faustman, Cameron; Venkitanarayanan, Kumar

2007-07-01

373

Structural analysis of fructans produced by acetic acid bacteria reveals a relation to hydrocolloid function.  

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Some strains of acetic acid bacteria (Gluconobacter frateurii TMW 2.767, Gluconobacter cerinus DSM 9533T, Neoasaia chiangmaiensis NBRC 101099, Kozakia baliensis DSM 14400) produce high amounts of fructans, which can be exploited in food applications as previously demonstrated empirically for dough systems. In order to get insight into the structure and functionality of these polymers, we investigated the fructans isolated from these strains with respect to their linkage types and molecular weights/shapes using NMR spectroscopy and AF4-MALS-RI. Each fructan was identified as levan. The isolated levan fractions were highly similar according to their basic linearity and linkage types, but differed significantly in terms of their individual molecular weight distributions. In aqueous solutions the size of levan molecules present in all isolated levans continuously increased with their molecular weight and they tended to adopt a more compact molecular shape. Our data suggest that the increasing molecular weight of a levan particle enforces intramolecular interactions to reach the structural compactness of a microgel with hydrocolloid properties. PMID:23399151

Jakob, Frank; Pfaff, Andre; Novoa-Carballal, Ramon; Rübsam, Heinrich; Becker, Thomas; Vogel, Rudi F

2013-02-15

374

Influence of Seed Treatment with Indole Acetic Acid on Mungbean Cultivation  

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Full Text Available The study was carried out in the Field Laboratory of the Department of Crop Botany, Bangladesh Agricultural University, Mymensingh during the period from October 2000 to February 2001 to evaluate the influence of seed treatment with Indole Acetic Acid (IAA by the concentration of 50 ppm, 100 ppm and 200 ppm on the growth, yield and yield contributing characters of two modern mungbean (Vigna radiata L. varieties viz. Barimoog-4 and Barimoog-5. The two-factor experiment was laid out by Randomized Complete Block Design (RCBD with 3 replications. In the experimental, seed treatment with 100 ppm IAA resulted the highest plant height, leaf area, leaf area index and number of seeds pod-1 (7.73. On the other hand, seed treatment with 200 ppm IAA resulted the highest Relative Growth Rate (RGR, Crop Growth Rate (CGR, Net Assimilation Rate (NAR, total dry matter, number of pods plant-1 (16.30, pod length (5.59 cm, fresh weight of pod plant-1 (13.00 g, dry weight of pod plant-1 (9.65 g, 1000-seed weight (40.10 g, seed yield plant-1 (4.99 g, harvest index (38.48. In addition, among the mungbean varieties, Binamoog-5 performed better than that of Binamoog-4.

Rumman Shafi Quaderi

2006-01-01

375

Fluorescent rhodanine-3-acetic acids visualize neurofibrillary tangles in Alzheimer's disease brains.  

Science.gov (United States)

There is a high demand for the development of an imaging agent for neurofibrillary tangles (NFTs) detection in Alzheimer's diagnosis. In the present study, a series of rhodanine-3-acetic acids was synthesized and evaluated for fluorescence imaging of NFTs in brain tissues of AD patients. Five out of seven probes have shown excellent binding affinity to NFTs over amyloid plaques in the Thiazine red R displacement assay. However, the selectivity in this in vitro assay is not confirmed by the histopathological evaluation, which indicates significant differences in the binding sites in the assays. Probe 6 showed binding affinity (IC50=19nM) to tau aggregates which is the highest among this series. Probes 2, 3, 4 and 5 display IC50 values of lower than 100nM to tau aggregates to displace Thiazine red R. Evaluation of the cytotoxicity of these five probes with human liver carcinoma cells revealed that these compounds excert negligible cytotoxicity. The in vivo studies with zebrafish embryos confirmed negligible cytotoxicity at 24 and 72h post fertilization. PMID:23859773

Anumala, Upendra Rao; Gu, Jiamin; Lo Monte, Fabio; Kramer, Thomas; Heyny-von Haußen, Roland; Hölzer, Jana; Goetschy-Meyer, Valerie; Schön, Christian; Mall, Gerhard; Hilger, Ingrid; Czech, Christian; Herms, Jochen; Schmidt, Boris

2013-09-01

376

Microstructural characterization of oxide film formed on NiTi by anodization in acetic acid  

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NiTi was galvanostatically anodized in acetic acid aiming at forming an anodic film for improving corrosion resistance. While the corrosion behavior of anodized NiTi in Hanks' solution was reported elsewhere [P. Shi, F.T. Cheng, H.C. Man, Mater. Lett., submitted for publication], the present work reports the microstructural characterization of the anodic film formed. Bright-field image of the sample cross-section captured by transmission electron microscopy (TEM) revealed an oxide film of about 20 nm thick, which was smooth and free of defects. The surface roughness R {sub a} of the film, determined by atomic force microscopy (AFM), was about 1.45 nm. Analysis by X-ray photoelectron spectroscopy (XPS) along the depth of the anodic film indicated that the oxidation state of Ti varied from +4 (corresponding to TiO{sub 2}) at the surface to lower oxidation states (corresponding to Ti suboxides) beneath. A small amount of Ni in the metallic and oxidized states was also present. The Ni/Ti atomic ratio was about 0.04 at the surface of the anodic film, which was much lower than the corresponding value of 0.30 for the mechanically polished samples. Selected-area diffraction (SAD) patterns and high-resolution TEM image of the anodic film showed that the film was amorphous.

Cheng, F.T. [Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong)]. E-mail: apaftche@polyu.edu.hk; Shi, P. [Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Department of Materials and Chemical Engineering, Liaoning Institute of Technology, Jinzhou, Liaoning (China); Pang, G.K.H. [Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Wong, M.H. [Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Man, H.C. [Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong)

2007-07-12

377

Enhanced acetic acid and succinic acid production under microaerobic conditions by Corynebacterium glutamicum harboring Escherichia coli transhydrogenase gene pntAB.  

Science.gov (United States)

Some microorganisms, such as Escherichia coli, harbor transhydrogenases that catalyze the interconversion between NADPH and NADH. However, such transhydrogenase genes have not been found in the genome of a glutamic acid-producing bacterium Corynebacterium glutamicum. In this study, the E. coli transhydrogenase genes udhA and pntAB were introduced into the C. glutamicum wild-type strain ATCC 13032, and the metabolic characteristics of the recombinant strains under aerobic and microaerobic conditions were examined. No major metabolic changes were observed following the introduction of the E. coli transhydrogenase genes under aerobic conditions. Under microaerobic conditions, significant metabolic change was not observed following the introduction of the udhA gene. However, the specific production rates of lactic acid, acetic acid, and succinic acid, and the overall production levels of acetic acid and succinic acid were increased by introducing the E. coli pntAB gene. Moreover, the NADH/NAD(+) ratio was increased by introduction of pntAB. Our results suggest that the E. coli PntAB transhydrogenase enhances the conversion of NADPH to NADH in C. glutamicum under microaerobic conditions, and the increased NADH/NAD(+) ratio results in increased succinic acid production. In addition, acetic acid production might be enhanced to supply ATP to the anaplerotic reaction catalyzed by pyruvate carboxylase. PMID:25008167

Yamauchi, Yuto; Hirasawa, Takashi; Nishii, Masato; Furusawa, Chikara; Shimizu, Hiroshi

2014-01-01

378

Synthesis of Ortho Acid Ester-Type 1,3-Dioxolanofullerenes: Radical Reaction of [60]Fullerene with Halocarboxylic Acids Promoted by Lead(IV) Acetate.  

Science.gov (United States)

A lead(IV) acetate-promoted radical reaction of [60]fullerene with halocarboxylic acids has been exploited to synthesize rare ortho acid ester-type 1,3-dioxolanofullerenes, the hydroxyl group of which can be further transformed to an ester or ether group. Intriguingly, an ortho acid ester-type 1,3-dioxolanofullerene can also be converted to a 1,4-dioxanonofullerene in the presence of a base or manipulated to another ortho acid ester-type 1,3-dioxolanofullerene by reaction with a stronger halocarboxylic acid. Moreover, two possible reaction pathways leading to the observed products are also proposed. PMID:25360886

You, Xun; Li, Fa-Bao; Wang, Guan-Wu

2014-11-21

379

Removing acidic components from natural gases in stratum conditions  

Energy Technology Data Exchange (ETDEWEB)

Results are examined of a study of the physical and chemical processes with occur with interaction between hydrogen sulfide and carbon dioxide in Terrigeneous rocks in conditions which are similar to stratum conditions. Data are cited from a pilot plant experiment for stratum removal of acidic components from a gas. The possibility of industrial use of the method for purifying natural gas through pumping is shown in the twelfth to thirteenth levels of the Mubarek deposit.

Grinman, B.Kh.; Ataullin, E.I.; Khvan, G.D.; Orlovskiy, M.Yu.

1983-01-01

380

Transport of indole-3-butyric acid and indole-3-acetic acid in Arabidopsis hypocotyls using stable isotope labeling.  

Science.gov (United States)

The polar transport of the natural auxins indole-3-butyric acid (IBA) and indole-3-acetic acid (IAA) has been described in Arabidopsis (Arabidopsis thaliana) hypocotyls using radioactive tracers. Because radioactive assays alone cannot distinguish IBA from its metabolites, the detected transport from applied [3H]IBA may have resulted from the transport of IBA metabolites, including IAA. To test this hypothesis, we used a mass spectrometry-based method to quantify the transport of IBA in Arabidopsis hypocotyls by following the movement of [13C1]IBA and the [13C1]IAA derived from [13C1]IBA. We also assayed [13C6]IAA transport in a parallel control experiment. We found that the amount of transported [13C1]IBA was dramatically lower than [13C6]IAA, and the IBA transport was not reduced by the auxin transport inhibitor N-1-naphthylphthalamic acid. Significant amounts of the applied [13C1]IBA were converted to [13C1]IAA during transport, but [13C1]IBA transport was independent of IBA-to-IAA conversion. We also found that most of the [13C1]IBA was converted to ester-linked [13C1]IBA at the apical end of hypocotyls, and ester-linked [13C1]IBA was also found in the basal end at a level higher than free [13C1]IBA. In contrast, most of the [13C6]IAA was converted to amide-linked [13C6]IAA at the apical end of hypocotyls, but very little conjugated [13C6]IAA was found in the basal end. Our results demonstrate that the polar transport of IBA is much lower than IAA in Arabidopsis hypocotyls, and the transport mechanism is distinct from IAA transport. These experiments also establish a method for quantifying the movement of small molecules in plants using stable isotope labeling. PMID:22323783

Liu, Xing; Barkawi, Lana; Gardner, Gary; Cohen, Jerry D

2012-04-01

 
 
 
 
381

Location of transported auxin in etiolated maize shoots using 5-azidoindole-3-acetic acid  

International Nuclear Information System (INIS)

A study was undertaken using the photoaffinity labeling agent, tritiated 5-azidoindole-3-acetic acid ([3H],5-N3IAA), to identify cells in the etiolated maize (Zea mays L.) shoot which transport auxin. Transport of [3H],5-N3IAA was shown to be polar, inhibited by 2,3,5-triiodobenzoic acid (TIBA) and essentially freely mobile. There was no detectable radiodecomposition of [3H],5-N3IAA within tissue kept in darkness for 4 hours. Shoot tissue which had taken up [3H],5-N3IAA was irradiated with ultraviolet light to covalently fix the photoaffinity labeling agent within cells that contained it at the time of photolysis. Subsequent microautoradiography showed that all cells contained radioactivity; however, the amount of radioactivity varied among different cell types. Epidermal cells contained the most radioactivity per area, approximately twofold more than other cells. Parenchyma cells in the mature stelar region contained the next largest amount and cortical cells, sieve tube cells, tracheary cells, and all cells in the leaf base contained the least amount of the radioactive label. Two observations suggest that the auxin within the epidermal cells is transported in a polar manner: (a) the amount of auxin in the epidermal cells is greatly reduced in the presence of TIBA, and (b) auxin accumulates on the apical side of a wound in the epidermis and is absent on the basal side. While these results indicate that auxin in the epidermis is polarly transported, this tissue cannot be the only pathway since the epidermis is only a small fraction of the shoot volume

382

Biofilm formation and indole-3-acetic acid production by two rhizospheric unicellular cyanobacteria.  

Science.gov (United States)

Microorganisms that live in the rhizosphere play a pivotal role in the functioning and maintenance of soil ecosystems. The study of rhizospheric cyanobacteria has been hampered by the difficulty to culture and maintain them in the laboratory. The present work investigated the production of the plant hormone indole-3-acetic acid (IAA) and the potential of biofilm formation on the rhizoplane of pea plants by two cyanobacterial strains, isolated from rice rhizosphere. The unicellular cyanobacteria Chroococcidiopsis sp. MMG-5 and Synechocystis sp. MMG-8 that were isolated from a rice rhizosphere, were investigated. Production of IAA by Chroococcidiopsis sp. MMG-5 and Synechocystis sp. MMG-8 was measured under experimental conditions (pH and light). The bioactivity of the cyanobacterial auxin was demonstrated through the alteration of the rooting pattern of Pisum sativum seedlings. The increase in the concentration of L-tryptophan and the time that this amino acid was present in the medium resulted in a significant enhancement of the synthesis of IAA (r > 0.900 at p = 0.01). There was also a significant correlation between the concentration of IAA in the supernatant of the cyanobacteria cultures and the root length and number of the pea seedlings. Observations made by confocal laser scanning microscopy revealed the presence of cyanobacteria on the surface of the roots and also provided evidence for the penetration of the cyanobacteria in the endorhizosphere. We show that the synthesis of IAA by Chroococcidiopsis sp. MMG-5 and Synechocystis sp. MMG-8 occurs under different environmental conditions and that the auxin is important for the development of the seedling roots and for establishing an intimate symbiosis between cyanobacteria and host plants. PMID:24705871

Ahmed, Mehboob; Stal, Lucas J; Hasnain, Shahida

2014-08-28

383

Attempting to monitor the incorporation of deuterium into indole-3-acetic acid and tryptophan in Zea mays grown on deuterium oxide labeled water  

Energy Technology Data Exchange (ETDEWEB)

We are attempting to determine when seedlings of Zea mays sweet corn, var. Silver Queen begin de novo biosynthesis of tryptophan and indole-3-acetic acid (IAA). We wish to use the general precursor, deuterium labeled water, to minimize assumptions as to the biosynthetic route. Protium in positions 2, 4, 5, 6 7 of the indole ring are non-exchangeable. IAA and tryptophan synthesized via the shikimic acid pathway would contain deuterium in one or more of these positions . The protium on the indene nitrogen, the carboxyl, the amino group, or the protium alpha to the carboxyl exchange readily and so are removed prior to analysis by base catalyzed exchange. The IAA, or trypotophan, is then purified by DEAE, Dowex 50, and two HPLC steps. IAA is methylated with diazomethane and analyzed by GC/MS. Trytophan is acetylated with triethylamine-acetic anhydride and then methylated with diazomethane and analyzed by GC/MS. Results of these studies on plants grown for varying lengths of time and under various light and nutrient conditions will be reported.

Jensen, P.J.; Bandurski, R.S. (Michigan State Univ., East Lansing (USA))

1989-04-01

384

An improved synthesis of 1,3,5-triaryl-2-pyrazolines in acetic acid aqueous solution under ultrasound irradiation  

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Full Text Available Abstract Background Pyrazoline derivatives have been found to possess a broad spectrum of biological activities. Among various pyrazoline derivatives, 2-pyrazolines seem to be the most frequently studied. A variety of methods have been reported for the preparation of this class of compound. However, in spite of their potential utilit