WorldWideScience
1

Development of Acetic Acid Removal Technology for the UREX+Process  

International Nuclear Information System (INIS)

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 downstream steps can be avoided. 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

2

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

3

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

OpenAIRE

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

4

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

Directory of Open Access Journals (Sweden)

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

Decontamination of aquatic vegetable leaves by removing trace toxic metals during pickling process with acetic acid solution.  

Science.gov (United States)

The heavy-metal content of aquatic plants is mainly dependent upon their ecological system. This study indicated that although the toxic heavy-metal contents could be above the recommended maximum levels depending upon their concentrations in growing water, they can be decontaminated by pickling with 5% acetic acid solution. Almost all Cd, Hg, Ba, or Sb and 99.5% Pb, 96.7% Ag, or 97.1% Al were removed from Water Spinach leaves by soaking in acetic acid solution. For Water-Shield leaves, almost all Cd, Hg, Pb, Ba, or Sb and 95.0% Ag or 96.1% Al were removed. For Watercress leaves, almost all Cd, Hg, Ba, or Sb and 99.0% Pb or 99.7% Ag were removed. For Water Hyacinth leaves, almost all Cd, Ba, or Sb and 99.0% Hg, 98.5% Pb, 95.0% Ag, or 98.7% Al were removed. PMID:21888602

Wu, Wenbiao; Yang, Yixing

2011-01-01

6

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

Directory of Open Access Journals (Sweden)

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

7

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

8

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,

9

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

OpenAIRE

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

Nomura, Yoshiyuki; Iwahara, Masayoshi; Hongo, Motoyoshi

1988-01-01

10

Vesicles protect activated acetic acid.  

Science.gov (United States)

Abstract Methyl thioacetate, or activated acetic acid, has been proposed to be central to the origin of life and 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 3 orders of magnitude faster (K=0.00663 s(-1); 100°C, pH 7.5, concentration=0.33 mM) than published rates for its catalyzed production, making it unlikely to accumulate under prebiotic conditions. However, our experiments showed that methyl thioacetate was protected from hydrolysis when inside its own hydrophobic droplets. Further, we found that methyl thioacetate protection from hydrolysis was also possible in droplets of hexane and in the membranes of nonanoic acid vesicles. Thus, the hydrophobic regions of prebiotic vesicles 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. This model of early energy storage evokes an additional critical function for the earliest cell membranes. PMID:25280019

Todd, Zoe R; House, Christopher H

2014-10-01

11

Isolation of acetic acid bacteria from honey  

OpenAIRE

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 showe...

Wasu Pathom-aree

2009-01-01

12

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

Science.gov (United States)

In this study, yeast and acetic acid bacteria strains were adopted to enhance the ethanol-type fermentation resulting to a volatile fatty acids yield of 30.22 g/L, and improve acetic acid production to 25.88 g/L, with food wastes as substrate. In contrast, only 12.81 g/L acetic acid can be obtained in the absence of strains. The parameters such as pH, oxidation reduction potential and volatile fatty acids were tested and the microbial diversity of different strains and activity of hydrolytic ferment were investigated to reveal the mechanism. The optimum pH and oxidation reduction potential for the acetic acid production were determined to be at 3.0-3.5 and -500 mV, respectively. Yeast can convert organic matters into ethanol, which is used by acetic acid bacteria to convert the organic wastes into acetic acid. The acetic acid thus obtained from food wastes micro-aerobic fermentation liquid could be extracted by distillation to get high-pure acetic acid. PMID:25416587

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

2015-05-01

13

Isolation of acetic acid bacteria from honey  

Directory of Open Access Journals (Sweden)

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

14

Labelling indole-3-acetic acid with tritium  

International Nuclear Information System (INIS)

A simple method for obtaining indole-3-acetic acid (growth stimulating plant hormone C10H9NO2) labelled with tritium is described. The preparate has specific radioactivity of 455 MBq/mmol, and 50% yield as compared to the initial amount of used substance. (author)

15

Biotechnological applications of acetic acid bacteria.  

Science.gov (United States)

The acetic acid bacteria (AAB) have important roles in food and beverage production, as well as in the bioproduction of industrial chemicals. In recent years, there have been major advances in understanding their taxonomy, molecular biology, and physiology, and in methods for their isolation and identification. AAB are obligate aerobes that oxidize sugars, sugar alcohols, and ethanol with the production of acetic acid as the major end product. This special type of metabolism differentiates them from all other bacteria. Recently, the AAB taxonomy has been strongly rearranged as new techniques using 16S rRNA sequence analysis have been introduced. Currently, the AAB are classified in ten genera in the family Acetobacteriaceae. AAB can not only play a positive role in the production of selected foods and beverages, but they can also spoil other foods and beverages. AAB occur in sugar- and alcohol-enriched environments. The difficulty of cultivation of AAB on semisolid media in the past resulted in poor knowledge of the species present in industrial processes. The first step of acetic acid production is the conversion of ethanol from a carbohydrate carried out by yeasts, and the second step is the oxidation of ethanol to acetic acid carried out by AAB. Vinegar is traditionally the product of acetous fermentation of natural alcoholic substrates. Depending on the substrate, vinegars can be classified as fruit, starch, or spirit substrate vinegars. Although a variety of bacteria can produce acetic acid, mostly members of Acetobacter, Gluconacetobacter, and Gluconobacter are used commercially. Industrial vinegar manufacturing processes fall into three main categories: slow processes, quick processes, and submerged processes. AAB also play an important role in cocoa production, which represents a significant means of income for some countries. Microbial cellulose, produced by AAB, possesses some excellent physical properties and has potential for many applications. Other products of biotransformations by AAB or their enzymes include 2-keto-L-gulonic acid, which is used for the production of vitamin C; D-tagatose, which is used as a bulking agent in food and a noncalorific sweetener; and shikimate, which is a key intermediate for a large number of antibiotics. Recently, for the first time, a pathogenic acetic acid bacterium was described, representing the newest and tenth genus of AAB. PMID:18568850

Raspor, Peter; Goranovic, Dusan

2008-01-01

16

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

17

Rapid Economic, Acetic Acid, Papanicolaou Stain (REAP) -  

OpenAIRE

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 s...

Ranu RoyBiswas

2008-01-01

18

Rapid Economic, Acetic Acid, Papanicolaou Stain (REAP -  

Directory of Open Access Journals (Sweden)

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

19

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

Science.gov (United States)

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

Donahue, Craig J.; Panek, Mary G.

1985-01-01

20

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

OpenAIRE

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

21

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

22

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

23

Simultaneous introduction of nitric, acetic and trifluoroacetic acids into anthracite  

Energy Technology Data Exchange (ETDEWEB)

Absorption tests are discussed made using Donetsk anthracite and acetic, trifluoroacetic and nitric acids. Results obtained indicate that reaction is exothermic and that nitric acid vapor increases absorption of carboxylic acid. A similar effect is shown by potassium nitrate deposited on anthracite. Much faster oxidestruction takes place in a mixture of nitric acid and helium. AcOH molecules exert a stabilizing effect, stop reaction at chemisorption stage and prevent oxidestruction. Effect is analyzed of nitric and acetic acids on oxidestruction and it is concluded that at 130 C initial absorption rate of nitric acid is approximately 40 times that of acetic acid. Anthracite in a mixture of nitric and acetic acids absorbs nitric acid first and thus facilitates absorption of carboxylic acid at later stages. Synergism occurs on absorption of mixture of nitric and acetic acids. Presence of nitric acid increases sorption of carboxylic acid which in turn stabilizes sorbent and promotes further absorption of nitric acid, thus considerably increasing sorption capacity of anthracite. 4 refs.

Rudakov, E.S.; Sapunov, V.A.; Metlova, L.P.; Kucherenko, V.A.; Zverev, I.V.

1986-11-01

24

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

25

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).

26

Acetic acid production from marine algae. Progress report No. 2, September 30--December 31, 1977  

Energy Technology Data Exchange (ETDEWEB)

Preliminary results on the production of acetic acid from marine algae by anaerobic fermentation indicate that the rate is quite fast. First order rate constants of 0.77 day/sup -1/ were observed. This rate constant gives a half-life of less than one day. In other words, with a properly designed product removal system a five day retention time would yield 98% of theoretical conversion. Determination of the theoretical conversion of marine algae to acetic acid is the subject of much experimentation. The production of one acetic acid molecule (or equivalent in higher organic acids) for each three carbon atoms in the substrate has been achieved; but it is possible that with a mixed culture more than one acetic acid molecule may be produced for each three carbons in the substrate. Work is continuing to improve the yield of acetic acid from marine algae. Marine algae have been found to be rather low in carbon, but the carbon appears to be readily available for fermentation. It, therefore, lends itself to the production of higher value chemicals in relatively expensive equipment, where the rapid conversion rate is particularly cost effective. Fixed packed bed fermenters appear to be desirable for the production of liquid products which are inhibitory to the fermentation from coarse substrates. The inhibitory products may be removed from the fermentation by extraction during recirculation. This technique lends itself to either conventional processing or low capital processing of substrates which require long retention times.

1977-01-01

27

Biosynthesis of the halogenated auxin, 4-chloroindole-3-acetic acid.  

Science.gov (United States)

Seeds of several agriculturally important legumes are rich sources of the only halogenated plant hormone, 4-chloroindole-3-acetic acid. However, the biosynthesis of this auxin is poorly understood. Here, we show that in pea (Pisum sativum) seeds, 4-chloroindole-3-acetic acid is synthesized via the novel intermediate 4-chloroindole-3-pyruvic acid, which is produced from 4-chlorotryptophan by two aminotransferases, TRYPTOPHAN AMINOTRANSFERASE RELATED1 and TRYPTOPHAN AMINOTRANSFERASE RELATED2. We characterize a tar2 mutant, obtained by Targeting Induced Local Lesions in Genomes, the seeds of which contain dramatically reduced 4-chloroindole-3-acetic acid levels as they mature. We also show that the widespread auxin, indole-3-acetic acid, is synthesized by a parallel pathway in pea. PMID:22573801

Tivendale, Nathan D; Davidson, Sandra E; Davies, Noel W; Smith, Jason A; Dalmais, Marion; Bendahmane, Abdelhafid I; Quittenden, Laura J; Sutton, Lily; Bala, Raj K; Le Signor, Christine; Thompson, Richard; Horne, James; Reid, James B; Ross, John J

2012-07-01

28

Synthesis of the ?-D-glucosyl ester of [carbonyl-13C]-indole-3-acetic acid  

International Nuclear Information System (INIS)

An efficient, operationally simple synthetic approach to 1-O-([carbonyl-13C]-indole-3'-ylacetyl)-?-D-glucopyranose is described. The synthesis was carried out by fusing a fully benzylated 1-O-glucosylpseudourea intermediate with [carbonyl-13C]-indole-3-acetic acid, followed by hydrogenolytic removal of the protective groups. (Author)

29

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

Directory of Open Access Journals (Sweden)

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

30

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

OpenAIRE

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...

Mandagara?n, B. A.; Campanella, E. A.

2006-01-01

31

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)

32

Recovery of Acetic Acid From Effluent via Freeze Crystallization  

Directory of Open Access Journals (Sweden)

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

2013-04-01

33

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

Degradation by acetic acid for crystalline Si photovoltaic modules  

Science.gov (United States)

The degradation of crystalline Si photovoltaic modules during damp-heat test was studied using some test modules with and without polymer film insertion by observing electrical and electroluminescence properties and by chemical analyses. Acetic acid generated by the hydrolysis decomposition of ethylene vinyl acetate used as an encapsulant is the main origin of degradation. The change in electroluminescence images is explained on the basis of the corrosion of electrodes by acetic acid. On the other hand, little change was observed at the pn junction even after damp-heat test for a long time. Therefore, carrier generation occurs even after degradation; however, such generated carriers cannot be collected owing to corrosion of electrodes. The guiding principle that module structure and module materials without saving acetic acid into the modules was obtained.

Masuda, Atsushi; Uchiyama, Naomi; Hara, Yukiko

2015-04-01

35

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

36

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.

37

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

38

Tetrazole acetic acid: Tautomers, conformers, and isomerization  

International Nuclear Information System (INIS)

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

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

Origin and fate of acetate in an acidic fen.  

Science.gov (United States)

Acetate is a central intermediate in the anaerobic degradation of organic matter, and the resolution of its metabolism necessitates integrated strategies. This study aims to (1) estimate the contribution of acetogenesis to acetate formation in an acidic fen (pH ~ 4.9), (2) assess the genetic potential for acetogenesis targeting the fhs gene encoding formyltetrahydrofolate synthetase (FTHFS) and (3) unravel the in situ turnover of acetate using stable carbon isotope pore-water analysis. H(2)/CO(2)-supplemented peat microcosms yielded (13)C-depleted acetate (-37.2‰ vs. VPDB (Vienna Peedee belemnite standard) compared with -14.2‰ vs. VPDB in an unamended control), indicating the potential for H(2)-dependent acetogenesis. Molecular analysis revealed a high diversity and depth-dependent distribution of fhs phylotypes with the highest number of operational taxonomic units in 0-20 cm depth, but only few and distant relationships to known acetogens. In pore waters, acetate concentrations (0-170 ?M) and ?(13)C-values varied widely (-17.4‰ to -3.4‰ vs. VPDB) and did not indicate acetogenesis, but pointed to a predominance of sinks, which preferentially consumed (12)C-acetate, like acetoclastic methanogenesis. However, depth profiles of methane and ?(13)C(CH4) revealed a temporarily and spatially restricted role of this acetate sink and suggest other processes like sulfate and iron reduction played an important role in acetate turnover. PMID:22404042

Hädrich, Anke; Heuer, Verena B; Herrmann, Martina; Hinrichs, Kai-Uwe; Küsel, Kirsten

2012-08-01

41

Acetic Acid Increases Stability of Silage under Aerobic Conditions  

Science.gov (United States)

The effects of various compounds on the aerobic stability of silages were evaluated. It has been observed that inoculation of whole-crop maize with homofermentative lactic acid bacteria leads to silages which have low stability against aerobic deterioration, while inoculation with heterofermentative lactic acid bacteria, such as Lactobacillus brevis or Lactobacillus buchneri, increases stability. Acetic acid has been proven to be the sole substance responsible for the increased aerobic stability, and this acid acts as an inhibitor of spoilage organisms. Therefore, stability increases exponentially with acetic acid concentration. Only butyric acid has a similar effect. Other compounds, like lactic acid, 1,2-propanediol, and 1-propanol, have been shown to have no effect, while fructose and mannitol reduce stability. PMID:12514042

Danner, H.; Holzer, M.; Mayrhuber, E.; Braun, R.

2003-01-01

42

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

43

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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 predict [...] ing 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; E. A., Campanella.

2006-03-01

44

Disinfection of mung bean seed with gaseous acetic acid.  

Science.gov (United States)

Mung bean seed inoculated with Salmonella Typhimurium, Escherichia coli O157:H7, and Listeria monocytogenes (3 to 5 log CFU/g) was exposed to gaseous acetic acid in an aluminum fumigation chamber. Salmonella Typhimurium and E. coli O157:H7 were not detected by enrichment of seeds treated with 242 microl of acetic acid per liter of air for 12 h at 45 degrees C. L. monocytogenes was recovered by enrichment from two of 10 25-g seed samples treated in this manner. Fumigation with gaseous acetic acid was also lethal to indigenous bacteria and fungi on mung bean seed. The treatment did not significantly reduce seed germination rates, and no differences in surface microstructure were observed between treated and untreated seed viewed by scanning electron microscopy. PMID:10456753

Delaquis, P J; Sholberg, P L; Stanich, K

1999-08-01

45

Photoionization of small sodium-doped acetic acid clusters.  

Science.gov (United States)

The uptake of sodium and the fragmentation before and after "soft" photoionization with ultraviolet light are investigated for small acetic acid clusters. The acetic acid clusters are generated in a supersonic expansion and ionized with ultraviolet light after doping with sodium in a pick-up chamber. The composition of the bare acetic acid clusters in the molecular beam is determined independently from complementary photoionization experiments using extreme ultraviolet light. The experimental results are analyzed with the help of density functional calculations for energetics and statistical adiabatic channel calculations for fragmentation kinetics. The study demonstrates that the detected ions originate from fragmentation in the neutral as well as in the ionic state, and in particular that the fragmentation pathway strongly depends on the cluster size. PMID:21384976

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

2011-03-01

46

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

47

Electrochemistry of caffeic acid in acetate-ethanolic solutions  

OpenAIRE

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 p...

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

2006-01-01

48

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

49

Stable-isotope labeled metabolites of the phytohormone, indole-3-acetic acid  

Energy Technology Data Exchange (ETDEWEB)

1,3-Dicyclohexylcarbodimide-mediated condensation of [3a,4,5,6,7,7a-{sup 13}C{sub 6}]indole-3-acetic acid with the bis(tert-butyl) esters of L-aspartic or L-glutamic acids, followed by removal of the ester groups by dilute alkali, afforded N-([3a,4,5,6,7,7a-{sup 13}C{sub 6}] indol-3-ylacetyl)-L-aspartic and N-([3a,4,5,6,7,7a-{sup 13}C{sub 6}]indol-3-ylacetyl-L-glutamic) acids, labeled forms of compounds involved in the regulation of plant growth and development. The corresponding conjugates of (R,S)-2,3-dihydro-2-oxoindole-3-acetic acid, which are likewise of physiological significance, were labeled with {sup 15}N in the amino moieties and were synthesized via the N-hydroxysuccinimide ester. (author).

Ilic, Nebojsa [Maryland Univ., Plant Biology Dept., College Park, MD (United States); Magnus, Volker [Ruder Boskovic Inst., Organic Chemistry and Biochemistry Dept., Zagreb (Croatia); Ostin, Anders; Sandberg, Goeran [Swedish Univ. of Agricultural Sciences, Forest Genetics and Plant Physiology Dept., Umeaa (Sweden)

1997-05-01

50

Stable-isotope labeled metabolites of the phytohormone, indole-3-acetic acid  

International Nuclear Information System (INIS)

1,3-Dicyclohexylcarbodimide-mediated condensation of [3a,4,5,6,7,7a-13C6]indole-3-acetic acid with the bis(tert-butyl) esters of L-aspartic or L-glutamic acids, followed by removal of the ester groups by dilute alkali, afforded N-([3a,4,5,6,7,7a-13C6] indol-3-ylacetyl)-L-aspartic and N-([3a,4,5,6,7,7a-13C6]indol-3-ylacetyl-L-glutamic) acids, labeled forms of compounds involved in the regulation of plant growth and development. The corresponding conjugates of (R,S)-2,3-dihydro-2-oxoindole-3-acetic acid, which are likewise of physiological significance, were labeled with 15N in the amino moieties and were synthesized via the N-hydroxysuccinimide ester. (author)

51

Highly Concentrated Acetic Acid Poisoning: 400 Cases Reviewed  

Directory of Open Access Journals (Sweden)

Full Text Available Background: Caustic substance ingestion is known for causing a wide array of gastrointestinal and systemic complications. In Russia, ingestion of acetic acid is a major problem which annually affects 11.2 per 100,000 individuals. The objective of this study was to report and analyze main complications and outcomes of patients with 70% concentrated acetic acid poisoning. Methods: This was a retrospective study of patients with acetic acid ingestion who were treated at Sverdlovsk Regional Poisoning Treatment Center during 2006 to 2012. GI mucosal injury of each patient was assessed with endoscopy according to Zargar’s scale. Data analysis was performed to analyze the predictors of stricture formation and mortality. Results: A total of 400 patients with median age of 47 yr were included. GI injury grade I was found in 66 cases (16.5%, IIa in 117 (29.3%, IIb in 120 (30%, IIIa in 27 (16.7% and IIIb in 70 (17.5%. 11% of patients developed strictures and overall mortality rate was 21%. Main complications were hemolysis (55%, renal injury (35%, pneumonia (27% and bleeding during the first 3 days (27%. Predictors of mortality were age 60 to 79 years, grade IIIa and IIIb of GI injury, pneumonia, stages “I”, “F” and “L” of kidney damage according to the RIFLE scale and administration of prednisolone. Predictors of stricture formation were ingestion of over 100 mL of acetic acid and grade IIb and IIIa of GI injury. Conclusion: Highly concentrated acetic acid is still frequently ingested in Russia with a high mortality rate. Patients with higher grades of GI injury, pneumonia, renal injury and higher amount of acid ingested should be more carefully monitored as they are more susceptible to develop fatal consequences.          

Konstantin Brusin

2012-12-01

52

Electrosynthesis of anisidines in aqueous sulfuric and acetic acids  

Science.gov (United States)

The influence of the concentrations of acetic and sulfuric acids on the efficiency of anisole amination by means of hydroxylamine and Ti(IV)/Ti(III) mediator was studied. Ortho- and para-anisidines were obtained with the total yields of about 79% by current and hydroxylamine.

Lisitsyn, Yu. A.; Grigor'eva, L. V.

2009-03-01

53

2-(Benzene­sulfonamido)acetic acid  

OpenAIRE

The title compound, C8H9NO4S, is of inter­est as a precursor to biologically active sulfur-containing heterocyclic cmpounds. The crystal structure displays the classical O—H?O inter­molecular hydrogen bonding typical for carboxylic acids forming dimers. Symmetry-related dimers are, in turn, linked through head-to-tail pairs of inter­molecular N—H?O inter­actions, giving rise to a zigzag chain along the c axis.

Arshad, Muhammad Nadeem; Khan, Islam Ullah; Zia-ur-rehman, Muhammad

2008-01-01

54

Kinetic stability of the dysprosium(3) complex with tetraazaporphine in acetic acid-water and acetic acid-methanol mixtures  

International Nuclear Information System (INIS)

Water-soluble dysprosium tetraazaporphine with acetylacetonate-ion as extraligand is synthesized for the first time. Its kinetic stability in acetic acid solutions is investigated. It is shown that the complex is dissociated with formation of free tetraazaporphine. Kinetic parameters of dissociation reaction are determined

55

Acetic acid formation via the hydration of gas-phase ketene under ambient conditions  

Science.gov (United States)

We have monitored changes in the infrared spectrum of gas-phase ketene in the presence of water vapor at 295 K. The products observed from ketene hydration are acetic acid, acetic acid dimer, and acetic anhydride. The time-dependence of product formation supports a reaction mechanism in which ketene hydrates to form acetic acid, which then combines with another acetic acid monomer to form a dimer, or with ketene to form acetic anhydride. These results show that ketene can undergo hydration under atmospherically-relevant temperatures and relative humidities. This reaction could be a source of atmospheric carboxylic acids, especially in biomass burning plumes.

Kahan, Tara F.; Ormond, Thomas K.; Ellison, G. Barney; Vaida, Veronica

2013-04-01

56

Formic and acetic acid aggregation in the liquid state  

International Nuclear Information System (INIS)

The microscopic structure of neat formic and acetic acid have been measured by neutron diffraction with H/D substitution on SANDALS at the ISIS neutron spallation source. These data, together with complementary x-ray data, have been modeled via the empirical potential structure refinement (EPSR) method, which integrates information obtained from the diffraction data in a Monte Carlo simulation in order to provide a three-dimensional model of the system under study compatible with the measured structure factors. Two models have been generated for each acid, in order to test their consistency, with positive results. The final structure obtained is that of two liquids that are very similar to each other, with high connectivity although rather disordered. They present a hierarchy of probability for hydrogen bond formation, where weaker bonds involving the carbonyl hydrogen for formic acid or the methyl hydrogen for acetic acid are more abundant than the stronger bonds involving the hydroxyl hydrogen. Cooperative effects are found to be fundamental for the description of aggregation of formic and acetic acid, but the structure in the liquid presents a greater variety of bonds than in the solid state.

57

Formic and acetic acid aggregation in the liquid state  

Energy Technology Data Exchange (ETDEWEB)

The microscopic structure of neat formic and acetic acid have been measured by neutron diffraction with H/D substitution on SANDALS at the ISIS neutron spallation source. These data, together with complementary x-ray data, have been modeled via the empirical potential structure refinement (EPSR) method, which integrates information obtained from the diffraction data in a Monte Carlo simulation in order to provide a three-dimensional model of the system under study compatible with the measured structure factors. Two models have been generated for each acid, in order to test their consistency, with positive results. The final structure obtained is that of two liquids that are very similar to each other, with high connectivity although rather disordered. They present a hierarchy of probability for hydrogen bond formation, where weaker bonds involving the carbonyl hydrogen for formic acid or the methyl hydrogen for acetic acid are more abundant than the stronger bonds involving the hydroxyl hydrogen. Cooperative effects are found to be fundamental for the description of aggregation of formic and acetic acid, but the structure in the liquid presents a greater variety of bonds than in the solid state.

Imberti, Silvia; Bowron, Daniel T, E-mail: silvia.imberti@stfc.ac.u [STFC, ISIS facility, Rutherford Appleton Laboratory, Didcot, OX11 0QX (United Kingdom)

2010-10-13

58

Formic and acetic acid aggregation in the liquid state.  

Science.gov (United States)

The microscopic structure of neat formic and acetic acid have been measured by neutron diffraction with H/D substitution on SANDALS at the ISIS neutron spallation source. These data, together with complementary x-ray data, have been modeled via the empirical potential structure refinement (EPSR) method, which integrates information obtained from the diffraction data in a Monte Carlo simulation in order to provide a three-dimensional model of the system under study compatible with the measured structure factors. Two models have been generated for each acid, in order to test their consistency, with positive results. The final structure obtained is that of two liquids that are very similar to each other, with high connectivity although rather disordered. They present a hierarchy of probability for hydrogen bond formation, where weaker bonds involving the carbonyl hydrogen for formic acid or the methyl hydrogen for acetic acid are more abundant than the stronger bonds involving the hydroxyl hydrogen. Cooperative effects are found to be fundamental for the description of aggregation of formic and acetic acid, but the structure in the liquid presents a greater variety of bonds than in the solid state. PMID:21386573

Imberti, Silvia; Bowron, Daniel T

2010-10-13

59

[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

60

[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

61

(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

62

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

Science.gov (United States)

...FRL-8841-2] Acetic Acid Ethenyl Ester, Polymer With Oxirane; Tolerance Exemption...tolerance for residues of acetic acid ethenyl ester, polymer with oxirane; when used as an...level for residues of acetic acid ethenyl ester, polymer with oxirane on food or...

2010-08-25

63

Acetic acid enhanced purification of crude cellulose from sugarcane bagasse: Structural and morphological characterization  

OpenAIRE

Crude cellulose prepared from alkali-extracted sugarcane bagasse was subjected to a rapid purification treatment with a mixture of 80% acetic acid-68% nitric acid (10/1, v/v) at 120 °C for 15 min. The yields of the preparations decreased slightly from 57.3%-58.6% in the crude cellulose preparations to 50.3%-51.9% in the purified cellulose samples. The purification treatment removed large amounts of resistant hemicelluloses strongly associated to the cellulose. XRD analysis revealed that the ...

Jing Bian; Feng Peng; Xiao-Peng Peng; Pai Peng; Feng Xu; Run-Cang Sun

2012-01-01

64

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.

65

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 tuhavior 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

66

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

67

Benzylidene acetal type bridged nucleic acids: changes in properties upon cleavage of the bridge triggered by external stimuli.  

Science.gov (United States)

Four classes of benzylidene acetal type bridged nucleic acids (BA-BNAs) were designed with 2',4'-bridged structures that cleaved upon exposure to appropriate external stimuli. Cleavage of 6-nitroveratrylidene and 2-nitrobenzylidene acetal type BNA bridges occurred upon photoirradiation and subsequent treatment with thiol caused changes in secondary structure to afford 4'-C-hydroxymethyl RNA. Benzylidene and 4-nitrobenzylidene acetal type BNA responded to acids and reducing agents, respectively, resulting in hydrolysis of the acetal-bridged structure. Cleavage of the bridge removed sugar conformational restrictions and changed the duplex- and triplex-forming properties of the BNA-modified oligonucleotides. Moreover, oligonucleotides incorporating a single BA-BNA modification had considerably improved stability toward 3'-exonuclease, which was lost upon cleavage of the bridge. Thus, these new BNAs may be useful as therapeutic and detection tools by sensing various environments. PMID:21644240

Morihiro, Kunihiko; Kodama, Tetsuya; Obika, Satoshi

2011-07-01

68

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

69

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

Energy Technology Data Exchange (ETDEWEB)

Graphical abstract: Model evaluation applied to case study 1: (A-G) S{sup 2?}, NO{sub 3}{sup ?}-N, NO{sub 2}{sup ?}-N, and Ac{sup ?}-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{sup ?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 (S{sup 2?}), nitrate (NO{sub 3}{sup ?}) and acetate (Ac{sup ?}) 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 S{sup 2?} concentration, S{sup 2?}/NO{sub 3}{sup ?}-N ratio and Ac{sup ?}-C/NO{sub 3}{sup ?}-N ratio. Simulation supported that the heterotrophic denitratation step (NO{sub 3}{sup ?} reduction to NO{sub 2}{sup ?}) was inhibited by S{sup 2?} compared with the denitritation step (NO{sub 2}{sup ?} reduction to N{sub 2}). Also, the S{sup 2?} oxidation by autotrophic denitrifiers was shown two times lower in rate with NO{sub 2}{sup ?} as electron acceptor than that with NO{sub 3}{sup ?} as electron acceptor. NO{sub 3}{sup ?} reduction by autotrophic denitrifiers occurs 3–10 times slower when S{sup 0} participates as final electron donor compared to the S{sup 2?}-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 S{sup 2?} 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.

Xu, Xijun; Chen, Chuan; Wang, Aijie; Guo, Wanqian; Zhou, Xu [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Lee, Duu-Jong, E-mail: djlee@ntu.edu.tw [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan (China); Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Ren, Nanqi, E-mail: rnq@hit.edu.cn [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Chang, Jo-Shu [Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan, Taiwan (China)

2014-01-15

70

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

71

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; Christiansen, Sofie Egholm

2007-01-01

72

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

73

Role of free acetic acid on the CO{sub 2} corrosion of steels  

Energy Technology Data Exchange (ETDEWEB)

Field experience has shown that CO{sub 2}corrosion is considerably reduced at low partial pressures, unless more than 0.1 to 1 mM of acetic acid is present in the water. This paper shows that acetic species actually act as a weak inhibitor of the anodic dissolution reaction, and that the role of acetic acid is clearly related to an associated inversion of the acetate/bicarbonate ratio, together with the resulting difficulty in precipitating protective iron carbonate. In addition, despite its minute concentration, acetic acid becomes the main source of the acidity consumed by corrosion. In such conditions, a genuine acetic acid corrosion occurs, controlled by a volubility equilibrium with a gas phase containing acetic acid vapor, like in the case of CO{sub 2} corrosion.

Crolet, J.L. [Elf Exploration Production, Pau (France); Thevenot, N.; Dugstad, A. [Inst. for Energiteknikk, Kjeller (Norway)

1999-11-01

74

Anion exchange process in acetic acid medium as a reconversion method for reprocessing of J-rods  

International Nuclear Information System (INIS)

In the earlier reprocessing campaign of J-rods (thorium metal and oxide pellets contained in Al cans; irradiated in the Cirus reactor), two reconversion methods namely anion exchange process in hydrochloric acid medium and oxalate precipitation route were followed. The product solution of 233U contained about 5% iron in addition to thorium impurity. In both the methods, thorium could be removed whereas iron impurity remained. Removal of iron impurity from the 233U oxide product required a subsequent solvent extraction method. In the present method of anion exchange separation, in acetic acid medium, both thorium and iron impurities are removed avoiding a separate solvent extraction purification. (author). 4 refs

75

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)

76

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

77

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

78

Kinetic Modeling of Esterification of Ethylene Glycol with Acetic Acid  

International Nuclear Information System (INIS)

The reaction kinetics of the esterification of ethylene glycol with acetic acid in the presence of cation exchange resin has been studied and kinetic models based on empirical and Langmuir approach has been developed. The Langmuir based model involving eight kinetic parameters fits experimental data much better compared to empirical model involving four kinetic parameters. The effect of temperature and catalyst loading on the reaction system has been analyzed. Further, the activation energy and frequency factor of the rate constants for Langmuir based model has been estimated.

79

Radioiron utilization and gossypol acetic acid in male rats  

Energy Technology Data Exchange (ETDEWEB)

The 24-h incorporation of VZFe into circulating red blood cells, bone marrow, urine, liver, spleen, and skeletal muscle was measured in splenectomized and sham-splenectomized rats which had received a daily, oral dose of gossypol acetic acid (20 mg GAA/kg body wt) for 91 days. A significant decrease in total body weight gain was observed in all GAA treated animals. Splenectomized rats dosed with GAA exhibited a significant decrease in hemoglobin concentration, hematocrit and erythrocyte count. A significant increase in VZFe incorporation by red blood cells and a decrease in hepatic incorporation of VZFe indicate a preferential utilization of iron in erythropoiesis among GAA treated animals.

Tone, J.N.; Jensen, D.R.

1985-01-01

80

Indole 3-acetic acid production by ectomycorrhizal fungi.  

Science.gov (United States)

Ability of 8 ectomycorrhizal fungi to synthesise indole 3-acetic acid from L-tryptophan and their growth rate were studied. Differences in the levels of IAA synthesis and biomass production among the 8 mycorrhizal fungi were observed. A positive correlation was recorded between IAA level and mycelial growth. The synthesis of IAA and mycelial biomass were maximum on 30th day after incubation. Pisolithus tinctorius and Laccaria laccata exhibited higher amounts of IAA production than other fungi, whereas Amanita muscaria and Rhizopogon luteolus showed least quantity of IAA. PMID:1521864

Gopinathan, S; Raman, N

1992-02-01

81

Radioiron utilization and gossypol acetic acid in male rats  

International Nuclear Information System (INIS)

The 24-h incorporation of 59Fe into circulating red blood cells, bone marrow, urine, liver, spleen, and skeletal muscle was measured in splenectomized and sham-splenectomized rats which had received a daily, oral dose of gossypol acetic acid (20 mg GAA/kg body wt) for 91 days. A significant decrease in total body weight gain was observed in all GAA treated animals. Splenectomized rats dosed with GAA exhibited a significant decrease in hemoglobin concentration, hematocrit and erythrocyte count. A significant increase in 59Fe incorporation by red blood cells and a decrease in hepatic incorporation of 59Fe indicate a preferential utilization of iron in erythropoiesis among GAA treated animals

82

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

International Nuclear Information System (INIS)

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 O2, 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 14C-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

83

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

Directory of Open Access Journals (Sweden)

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

84

The selective generation of acetic acid directly from synthesis gas  

International Nuclear Information System (INIS)

The authors conclude that each of the ruthenium, cobalt and iodide-containing catalyst components have very specific roles to play in the ''melt'' catalyzed conversion of synthesis gas to acetic acid. C1-Oxygenate formation is only observed in the presence of ruthenium carbonyls - [Ru(CO)3I3]- is here the dominant species - and there is a direct relationship between liquid yield, ?OAc-productivity and [Ru(CO)3I3]- content. Controlled quantities of iodide ensure that initially formed MeOH is rapidly converted to the more reactive methyl iodide. Subsequent cobalt-catalyzed carbonylation to acetic acid may be preparatively attractive (>80% selectivity, good yields) relative to competing syntheses, where the [Co(CO)4]- concentration is maximized that is, where the Co/Ru ratio is >1, the syngas feedstock is rich in CO, and the initial iodide/cobalt ratios are ca. unity. Formation of cobalt-iodide species appears to be a competing, inhibitory step in this catalysis

85

Diffusion of electrolytes in hydrolyzable glassy polymers: Acetic acid in poly(vinyl acetate), poly(vinyl alcohol), and polyesters  

OpenAIRE

Engineering materials containing poly(vinyl acetate) (PVAc) as the key component undergo hydrolytic degradation, which must be minimized or, at least, controlled. To characterize PVAc hydrolysis quantitatively, the diffusion of acetic acid (HAc) in PVAc, poly(vinyl alcohol) (PVA), unsaturated polyester (UPE), and a UPE/PVAc blend was studied in detail. The permeability cell earlier developed by the authors was modified here to reduce experimental error. As the diffusion and solubility coeffic...

Polishchuk, A. Ya; Valente, A. J. M.; Camino, G.; Luda, M. P.; Madyuskin, N. N.; Lobo, V. M. M.; Zaikov, G. E.; Revellino, M.

2002-01-01

86

Acetic acid recovery from a hybrid biological-hydrothermal treatment process of sewage sludge - a pilot plant study.  

Science.gov (United States)

A two-stage process consisting of anaerobic fermentation followed by sub-critical wet oxidation was used to generate acetic acid from sewage sludge at pilot scale. Volatile fatty acids, dominated by propionic acid, were produced over 4-6 days in the 2,000 L fermentation reactor, which also achieved 31% solids reduction. Approximately 96% of the carbon was retained in solution over the fermentation stage. Using a 200 L wet oxidation reactor operating in batch mode, the second stage achieved 98% volatile suspended solids (VSS) destruction and 67% total chemical oxygen demand (tCOD) destruction. Acetic acid produced in this stage was recalcitrant to further degradation and was retained in solution. The gross yield from VSS was 16% for acetic acid and 21% for volatile fatty acids across the process, higher than reported yields for wet oxidation alone. The pilot plant results showed that 72% of the incoming phosphorus was retained in the solids, 94% of the nitrogen became concentrated in solution and 41% of the carbon was converted to a soluble state, in a more degradable form. Acetic acid produced from the process has the potential to be used to offset ethanol requirements in biological nutrient removal plants. PMID:25768220

Andrews, J; Dare, P; Estcourt, G; Gapes, D; Lei, R; McDonald, B; Wijaya, N

2015-03-01

87

Recent advances in nitrogen-fixing acetic acid bacteria.  

Science.gov (United States)

Nitrogen is an essential plant nutrient, widely applied as N-fertilizer to improve yield of agriculturally important crops. An interesting alternative to avoid or reduce the use of N-fertilizers could be the exploitation of plant growth-promoting bacteria (PGPB), capable of enhancing growth and yield of many plant species, several of agronomic and ecological significance. PGPB belong to diverse genera, including Azospirillum, Azotobacter, Herbaspirillum, Bacillus, Burkholderia, Pseudomonas, Rhizobium, and Gluconacetobacter, among others. They are capable of promoting plant growth through different mechanisms including (in some cases), the biological nitrogen fixation (BNF), the enzymatic reduction of the atmospheric dinitrogen (N(2)) to ammonia, catalyzed by nitrogenase. Aerobic bacteria able to oxidize ethanol to acetic acid in neutral or acid media are candidates of belonging to the family Acetobacteraceae. At present, this family has been divided into ten genera: Acetobacter, Gluconacetobacter, Gluconobacter, Acidomonas, Asaia, Kozakia, Saccharibacter, Swaminathania, Neoasaia, and Granulibacter. Among them, only three genera include N(2)-fixing species: Gluconacetobacter, Swaminathania and Acetobacter. The first N(2)-fixing acetic acid bacterium (AAB) was described in Brazil. It was found inside tissues of the sugarcane plant, and first named as Acetobacter diazotrophicus, but then renamed as Gluconacetobacter diazotrophicus. Later, two new species within the genus Gluconacetobacter, associated to coffee plants, were described in Mexico: G. johannae and G. azotocaptans. A salt-tolerant bacterium named Swaminathania salitolerans was found associated to wild rice plants. Recently, N(2)-fixing Acetobacter peroxydans and Acetobacter nitrogenifigens, associated with rice plants and Kombucha tea, respectively, were described in India. In this paper, recent advances involving nitrogen-fixing AAB are presented. Their natural habitats, physiological and genetic aspects, as well as their association with different plants and contribution through BNF are described as an overview. PMID:18177965

Pedraza, Raúl O

2008-06-30

88

Diaterebic acid acetate and diaterpenylic acid acetate: atmospheric tracers for secondary organic aerosol formation from 1,8-cineole oxidation.  

Science.gov (United States)

Detailed organic speciation of summer time PM10 collected in Melbourne, Australia, indicated the presence of numerous monoterpene oxidation products that have previously been reported in the literature. In addition, two highly oxygenated compounds with molecular formulas C9H14O6 (MW 218) and C10H16O6 (MW 232), previously unreported, were detected during a period associated with high temperatures and bushfire smoke. These two compounds were also present in laboratory-produced secondary organic aerosol (SOA) through the reaction of OH radicals with 1,8-cineole (eucalyptol), which is emitted by Eucalyptus trees. The retention times and mass spectral behavior of the highly oxygenated compounds in high-performance liquid chromatography (LC) coupled to electrospray ionization-time-of-flight mass spectrometry (MS) in parallel to ion trap MS of agree perfectly between the ambient samples and the laboratory-produced SOA samples, suggesting that 1,8-cineole is the precursor of the highly oxygenated compounds. The proposed structure of the compound with molecular formula C10H16O6 was confirmed by synthesis of a reference compound. The two novel compounds were identified as diaterebic acid acetate (2-[1-(acetyloxy)-1-methylethyl]succinic acid, C9H14O6) and diaterpenylic acid acetate (3-[1-(acetyloxy)-1-methylethyl]glutaric acid, C10H16O6) based on the consideration of reaction mechanisms, the structure of a reference compound, and the interpretation of mass spectral data. Depending on the experimental conditions, the SOA yields determined in chamber experiments ranged between 16 and 20% for approximately 25 ppb of hydrocarbon consumed. The concentrations of these compounds were as high as 50 ng m(-3) during the summertime in Melbourne. This study demonstrates the importance and influence of local vegetation patterns on SOA chemical composition. PMID:19238952

Iinuma, Yoshiteru; Böge, Olaf; Keywood, Melita; Gnauk, Thomas; Herrmann, Hartmut

2009-01-15

89

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

90

Boron and ectomycorrhizal influences on indole-3-acetic acid levels and indole-3-acetic acid oxidase and peroxidase activities of Pinus echinata Mill. roots.  

Science.gov (United States)

The level of indole-3-acetic acid (IAA) in shortleaf pine (Pinus echinata Mill.) roots was increased by inoculation with the ectomycorrhizal fungus Pisolithus tinctorius (Pers.) Coker and Couch. Indole-3-acetic acid oxidase activity was also increased suggesting that the increased level of IAA was the result of increased synthesis. Boron fertilization reduced IAA levels in roots inoculated with P. tinctorius but not in noninoculated roots. PMID:14975901

Mitchell, R J; Garrett, H E; Cox, G S; Atalay, A

1986-06-01

91

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

Science.gov (United States)

Industrial microorganisms are subject to various stress conditions, including products and substrates inhibitions. Therefore, improvement of stress tolerance is of great importance for industrial microbial production. Acetic acid is one of the major inhibitors in the cellulosic hydrolysates, which affects seriously on cell growth and metabolism of Saccharomyces cerevisiae. Studies on the molecular mechanisms underlying adaptive response and tolerance of acetic acid of S. cerevisiae benefit breeding of robust strains of industrial yeast for more efficient production. In recent years, more insights into the molecular mechanisms underlying acetic acid tolerance have been revealed through analysis of global gene expression and metabolomics analysis, as well as phenomics analysis by single gene deletion libraries. Novel genes related to response to acetic acid and improvement of acetic acid tolerance have been identified, and novel strains with improved acetic acid tolerance were constructed by modifying key genes. Metal ions including potassium and zinc play important roles in acetic acid tolerance in S. cerevisiae, and the effect of zinc was first discovered in our previous studies on flocculating yeast. Genes involved in cell wall remodeling, membrane transport, energy metabolism, amino acid biosynthesis and transport, as well as global transcription regulation were discussed. Exploration and modification of the molecular mechanisms of yeast acetic acid tolerance will be done further on levels such as post-translational modifications and synthetic biology and engineering; and the knowledge obtained will pave the way for breeding robust strains for more efficient bioconversion of cellulosic materials to produce biofuels and bio-based chemicals. PMID:25007573

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

2014-03-01

92

Efficient sugar release by acetic acid ethanol-based organosolv pretreatment and enzymatic saccharification.  

Science.gov (United States)

Acetic acid ethanol-based organosolv pretreatment of sugar cane bagasse was performed to enhance enzymatic hydrolysis. The effect of different parameters (including temperature, reaction time, solvent concentration, and acid catalyst dose) on pretreatment prehydrolyzate and subsequent enzymatic digestibility was determined. During the pretreatment process, 11.83 g of xylose based on 100 g of raw material could be obtained. After the ethanol-based pretreatment, the enzymatic hydrolysis was enhanced and the highest glucose yield of 40.99 g based on 100 g of raw material could be obtained, representing 93.8% of glucose in sugar cane bagasse. The maximum total sugar yields occurred at 190 °C, 45 min, 60:40 ethanol/water, and 5% dosage of acetic acid, reaching 58.36 g (including 17.69 g of xylose and 40.67 g of glucose) based on 100 g of raw material, representing 85.4% of total sugars in raw material. Furthermore, characterization of the pretreated sugar cane bagasse using X-ray diffraction and scanning electron microscopy analyses were also developed. The results suggested that ethanol-based organosolv pretreatment could enhance enzymatic digestibilities because of the delignification and removal of xylan. PMID:25393929

Zhang, Hongdan; Wu, Shubin

2014-12-01

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

Genome-wide identification of Saccharomyces cerevisiae genes required for tolerance to acetic acid  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Acetic acid is a byproduct of Saccharomyces cerevisiae alcoholic fermentation. Together with high concentrations of ethanol and other toxic metabolites, acetic acid may contribute to fermentation arrest and reduced ethanol productivity. This weak acid is also a present in lignocellulosic hydrolysates, a highly interesting non-feedstock substrate in industrial biotechnology. Therefore, the better understanding of the molecular mechanisms underlying S. cerevisiae tolerance to acetic acid is essential for the rational selection of optimal fermentation conditions and the engineering of more robust industrial strains to be used in processes in which yeast is explored as cell factory. Results The yeast genes conferring protection against acetic acid were identified in this study at a genome-wide scale, based on the screening of the EUROSCARF haploid mutant collection for susceptibility phenotypes to this weak acid (concentrations in the range 70-110 mM, at pH 4.5. Approximately 650 determinants of tolerance to acetic acid were identified. Clustering of these acetic acid-resistance genes based on their biological function indicated an enrichment of genes involved in transcription, internal pH homeostasis, carbohydrate metabolism, cell wall assembly, biogenesis of mitochondria, ribosome and vacuole, and in the sensing, signalling and uptake of various nutrients in particular iron, potassium, glucose and amino acids. A correlation between increased resistance to acetic acid and the level of potassium in the growth medium was found. The activation of the Snf1p signalling pathway, involved in yeast response to glucose starvation, is demonstrated to occur in response to acetic acid stress but no evidence was obtained supporting the acetic acid-induced inhibition of glucose uptake. Conclusions Approximately 490 of the 650 determinants of tolerance to acetic acid identified in this work are implicated, for the first time, in tolerance to this weak acid. These are novel candidate genes for genetic engineering to obtain more robust yeast strains against acetic acid toxicity. Among these genes there are number of transcription factors that are documented regulators of a large percentage of the genes found to exert protection against acetic acid thus being considered interesting targets for subsequent genetic engineering. The increase of potassium concentration in the growth medium was found to improve the expression of maximal tolerance to acetic acid, consistent with the idea that the adequate manipulation of nutrient concentration of industrial growth medium can be an interesting strategy to surpass the deleterious effects of this weak acid in yeast cells.

Sá-Correia Isabel

2010-10-01

95

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

OpenAIRE

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 w...

BINCY JOHN; Pandeeswaran, M.; Bhuvaneshwari, D. S.; Elango, K. P.

2006-01-01

96

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

Science.gov (United States)

Acetic acid bacteria (AAB) play an important role during cocoa fermentation, as their main product, acetate, is a major driver for the development of the desired cocoa flavors. Here, we investigated the specialized metabolism of these bacteria under cocoa pulp fermentation-simulating conditions. A carefully designed combination of parallel 13C isotope labeling experiments allowed the elucidation of intracellular fluxes in the complex environment of cocoa pulp, when lactate and ethanol were included as primary substrates among undefined ingredients. We demonstrate that AAB exhibit a functionally separated metabolism during coconsumption of two-carbon and three-carbon substrates. Acetate is almost exclusively derived from ethanol, while lactate serves for the formation of acetoin and biomass building blocks. Although this is suboptimal for cellular energetics, this allows maximized growth and conversion rates. The functional separation results from a lack of phosphoenolpyruvate carboxykinase and malic enzymes, typically present in bacteria to interconnect metabolism. In fact, gluconeogenesis is driven by pyruvate phosphate dikinase. Consequently, a balanced ratio of lactate and ethanol is important for the optimum performance of AAB. As lactate and ethanol are individually supplied by lactic acid bacteria and yeasts during the initial phase of cocoa fermentation, respectively, this underlines the importance of a well-balanced microbial consortium for a successful fermentation process. Indeed, AAB performed the best and produced the largest amounts of acetate in mixed culture experiments when lactic acid bacteria and yeasts were both present. PMID:24837393

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

2014-08-01

97

Kinetics of reaction between acetic acid and Ag2+ in nitric acid medium  

International Nuclear Information System (INIS)

The reaction kinetics between acetic acid and Ag2+ in nitric acid medium is studied by spectrophotometry. The effects of concentrations of acetic acid (HAc), H+, NO3- and temperature on the reaction are investigated. The rate equation has been determined to be -dc(Ag2+)/dt=kc(Ag2+)c(HAc)c-1(H+), where k = (610±15) (mol/L)-1·min-1 with an activation energy of about (48.8±3.5) kJ·mol-1 when the temperature is 25degC and the ionic strength is 4.0 mol/L. The reduction rate of Ag2+ increases with the increase of HAc concentration or temperature and the decrease of HNO3 concentration. However, the effect of NO3- concentrations on the reaction rate is negligible. (author)

98

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

99

Acid gas removal in synfuels production  

Energy Technology Data Exchange (ETDEWEB)

The CO/sub 2/, H/sub 2/S and COS contents of gas streams of some synfuel processes and the costs for removal of these gases are tabulated. Four different types of acid gas removal processes discussed are chemisorption, physical adsorption, hybrid or combination of the first two, and sulfur conversion processes. Results of an economic study of H/sub 2/S and CO/sub 2/ removal at pressures of 1379, 2758, and 4137 kPa for 13.8 million normal m/sup 3//day of gas containing 1% H/sub 2/S and 22% CO/sub 2/. The processes considered were selective removal of H/sub 2/S with a solvent process (CATASOL 3) followed by removal of CO/sub 2/ by either the CATASOL 4A physical solvent or the CATACARB process (catalyzed hot potassium). The main feature influencing the selection of acid gas removal process are the gas composition and pressure and availability of low-level waste heat. Capital investment, utilities, and chemical costs were considered for various processes. Since the cost of commercial size synfuel process plants runs into billions of dollars, the added cost of acid gas removal must be carefully considered. (BLM)

Eickmeyer, A.G.; Gangriwala, H.A.

1981-12-01

100

Microbial process for the preparation of acetic acid, as well as solvent for its extraction from the fermentation broth  

Science.gov (United States)

A modified water-immiscible solvent useful in the extraction of acetic acid from aqueous streams is a substantially pure mixture of isomers of highly branched di-alkyl amines. Solvent mixtures formed of such a modified solvent with a desired co-solvent, preferably a low boiling hydrocarbon, are useful in the extraction of acetic acid from aqueous gaseous streams. An anaerobic microbial fermentation process for the production of acetic acid employs such solvents, under conditions which limit amide formation by the solvent and thus increase the efficiency of acetic acid recovery. Methods for the direct extraction of acetic acid and the extractive fermentation of acetic acid also employ the modified solvents and increase efficiency of acetic acid production. Such increases in efficiency are also obtained where the energy source for the microbial fermentation contains carbon dioxide and the method includes a carbon dioxide stripping step prior to extraction of acetic acid in solvent.

Gaddy, James L.; Clausen, Edgar C.; Ko, Ching-Whan; Wade, Leslie E.; Wikstrom, Carl V.

2007-03-27

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

Tolerance to acetic acid is improved by mutations of the TATA-binding protein gene.  

Science.gov (United States)

Screening a library of overexpressing mutant alleles of the TATA-binding gene SPT15 yielded two Saccharomyces cerevisiae strains (MRRC 3252 and 3253) with enhanced tolerance to acetic acid. They were also tolerant to propionic acid and hydrogen peroxide. Transcriptome profile analysis identified 58 upregulated genes and 106 downregulated genes in MRRC 3252. Stress- and protein synthesis-related transcription factors were predominantly enriched in the upregulated and downregulated genes respectively. Eight deletion mutants for some of the highly downregulated genes were acetic acid-tolerant. The level of intracellular reactive oxygen species was considerably lessened in MRRC 3252 and 3253 upon exposure to acetic acid. Metabolome profile analysis revealed that intracellular concentrations of 5 and 102 metabolites were increased and decreased, respectively, in MRRC 3252, featuring a large increase of urea and a significant decrease of amino acids. The dur1/2?mutant, in which the urea degradation gene DUR1/2 is deleted, displayed enhanced tolerance to acetic acid. Enhanced tolerance to acetic acid was also observed on the medium containing a low concentration of amino acids. Taken together, this study identified two SPT15 alleles, nine gene deletions and low concentration of amino acids in the medium that confer enhanced tolerance to acetic acid. PMID:24761971

An, Jieun; Kwon, Hyeji; Kim, Eunjung; Lee, Young Mi; Ko, Hyeok Jin; Park, Hongjae; Choi, In-Geol; Kim, Sooah; Kim, Kyoung Heon; Kim, Wankee; Choi, Wonja

2015-03-01

104

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

OpenAIRE

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 d...

Deepa D, Chandramohan G.

2013-01-01

105

Removal of ovarian hormones affects the ageing process of acetate metabolism  

Directory of Open Access Journals (Sweden)

Full Text Available Background: Despite a close association between gastrointestinal motility and sex hormones, it has been unknown whether ovarian hormones affect absorption and metabolism of nutrients. The aim of this study is, therefore, to evaluate metabolism of acetate in rats with age and the influence of ovariectomy on its change. Methods: Fourteen female rats of the F344 strain were used, and 13C-acetate breath test was performed at 2, 7 and 13 months of age. Seven rats were ovariectomized at three weeks of age (ovariectomy group and the remaining seven rats were studied as control group. After 24-hr fasting, rats are orally administrated 1ml of water containing sodium 13C-acetate (100mg/kg and housed in an animal chamber. The expired air in the chamber is collected in a breath-sampling bag using a aspiration pump. The 13CO2 concentration is measured using an infrared spectrometer for 120 min and expressed as delta per mil. Results: The breath 13CO2 excretion increased with time and peaked 30 min in control rats. In ovariectomized rats, thee peak time of 13CO2 excretion was prolonged to 40 min at 7 and 13 months of age. Cmax was significantly higher at 2 months of age but lower at 4 months of age in ovariectomized rats than in control rats. Those of two groups became equal at 7 months of age. Conclusions: From the viewpoint of acetate metabolism, removal of ovarian hormones might make rats to be precocious ones and accelerate ageing.

Tsunehiko Imai

2009-07-01

106

Metabolism of isobutylnaphthyl acetic acid in rats: determination of the chemical structures of metabolites.  

Science.gov (United States)

After oral and intravenous administration of radiolabelled isobutylnaphthyl acetic acid (INAA) to rats two metabolites were isolated from urine and plasma by HPLC. Field desorption, high resolution electron impact mass spectrometry as well as GC-MS after derivatization were used for structure elucidation and identification of the metabolites. The main biotransformation product in rat urine was found to be 5-(2'-hydroxy-2'-methyl-propyl)-1-naphthyl acetic acid (M1). The main metabolite in plasma was derived and was found to be 5-(2'-carboxypropyl)-1-naphthyl acetic acid (M2). PMID:2759131

Achtert, G; Borchers, F; Jacquot, C; Christen, M O

1989-01-01

107

1-Methylpyrrolidine-2-acetic Acid is not a Precursor of Tropane Alkaloids.  

Science.gov (United States)

1-Methylpyrrolidine-2-acetic acid and related compounds were studied as precursors in the biosynthesis of the tropane alkaloids in Erythroxylum coca and Datura innoxia. (R,S)-[1',2-(13)C2,2-(14)C,(15)N]-1-methylpyrrolidine-2- acid, (R,S)-[1',2'-(13)C2,1'-(14)C]-1-methylpyrrolidine-2-acetic acid, (R,S) [1',2'-(13)C2,1-(14)C]-1-methylpyrrolidine-2-acetate, and (R,S)-+2'-(14)C] methylpyrrolidine-2-acetic acid N-acetylcysteamine thioester were synthesized an intact plants by leaf-planting or hydroponic-feeding. Specific incorporation of compounds into ( - )-hyoscyamine, ( - )-scopolamine, ( - )-cocaine and the biosynthetically related cuscohygrine were very low. These results indicate that 1-methylpyrrolidine acid is not an efficient precursor of tropane alkaloids. PMID:8835455

Huang, M N; Abraham, T W; Kim, S H; Leete, E

1996-02-01

108

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

109

Structure-related lower surface resistivity and faster doping of poly(thiophene-3-acetic acid-co-3-hexylthiophene) compared with poly(thiophene-3-acetic acid)  

International Nuclear Information System (INIS)

Two types of electrically active polymers, namely poly(thiophene-3-acetic acid-co-3-hexylthiophene) or poly(TAA-co-HT), and poly(thiophene-3-acetic acid) or PTAA were synthesized by oxidizing polymerization, and compared in terms of structure, surface resistivity and doping rate. Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy data revealed that there is a smaller content of acetic acid functional groups in poly(TAA-co-HT) than in PTAA. Importantly, poly(TAA-co-HT) showed lower surface resistivity and higher doping rate when doped with iodine vapor in comparison with PTAA. The different surface resistivities and doping rates of the two polymers are related with the differences in their relative abundance of polar side groups and packing density of the polymer chains

110

Acute intestinal injury induced by acetic acid and casein: prevention by intraluminal misoprostol  

International Nuclear Information System (INIS)

Acute injury was established in anesthetized rabbits by intraluminal administration of acetic acid with and without bovine casein, into loops of distal small intestine. Damage was quantified after 45 minutes by the blood-to-lumen movement of 51Cr-labeled ethylenediaminetetraacetic acid (EDTA) and fluorescein isothiocyanate-tagged bovine serum albumin as well as luminal fluid histamine levels. The amount of titratable acetic acid used to lower the pH of the treatment solutions to pH 4.0 was increased by the addition of calcium gluconate. Luminal acetic acid caused a 19-fold increase in 51Cr-EDTA accumulation over saline controls; casein did not modify this effect. In saline controls, loop fluid histamine levels bordered on the limits of detection (1 ng/g) but were elevated 19-fold by acetic acid exposure and markedly increased (118-fold) by the combination of acid and casein. Intraluminal misoprostol (3 or 30 micrograms/mL), administered 30 minutes before acetic acid, significantly attenuated the increase in epithelial permeability (luminal 51Cr-EDTA, fluorescein isothiocyanate-bovine serum albumin accumulation) and histamine release (P less than 0.05). Diphenhydramine, alone or in combination with cimetidine, and indomethacin (5 mg/kg IV) were not protective. It is concluded that exposure of the epithelium to acetic acid promotes the transepithelial movement of casein leading to enhanced mast cell activation and mucosal injury. Damage ell activation and mucosal injury. Damage to the epithelial barrier can be prevented by misoprostol

111

Escherichia coli and Salmonella enterica Are Protected against Acetic Acid, but Not Hydrochloric Acid, by Hypertonicity?  

OpenAIRE

Chapman et al. (B. Chapman, N. Jensen, T Ross, and M. B. Cole, Appl. Environ. Microbiol. 72:5165-5172, 2006) demonstrated that an increased NaCl concentration prolongs survival of Escherichia coli O157 SERL 2 in a broth model simulating the aqueous phase of a food dressing or sauce containing acetic acid. We examined the responses of five other E. coli strains and four Salmonella enterica strains to increasing concentrations of NaCl under conditions of lethal acidity and observed that the ave...

Chapman, B.; Ross, T.

2009-01-01

112

Effect of chlorhexidine and acetic acid on phagocytosis by polymorphonuclear leucocytes.  

Science.gov (United States)

The effect of two disinfectants, chlorhexidine and acetic acid, on host leucocytes and bacteria was studied. At a concentration of 50 mg/l, chlorhexidine was found to be bactericidal without interfering with leucocyte function. A concentration of 500 mg/l of acetic acid was neither leucotoxic nor bactericidal. Effects equivalent to the aforementioned were achieved in serum by increasing the chlorhexidine concentration by a factor of 20 and the acetic acid concentration by a factor of 5. Acetic acid reduced leucocyte function more rapidly than it killed bacteria. On the basis of these findings, chlorhexidine is to be preferred for local application in burn wounds to prevent colonisation and infection. PMID:4065136

van Saene, J J; Veringa, S I; van Saene, H K; Verhoef, J; Lerk, C F

1985-10-01

113

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

Directory of Open Access Journals (Sweden)

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

114

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

115

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

116

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

Directory of Open Access Journals (Sweden)

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

117

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

OpenAIRE

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

118

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

OpenAIRE

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 characterizati...

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

2012-01-01

119

Synthesis of 14C-labeled halogen substituted indole-3-acetic acids  

International Nuclear Information System (INIS)

A general method for microscale synthesis of 14C-labeled indole-3-acetic acids with halogen substitutions in the benzene ring is described. The method utilizes halogen substituted phenylhydrazines reacted with [14C]-2-oxoglutarate to generate the halogenated indole-3-acetic acid. 3-Chlorophenyl-hydrazine yielded a mixture of the 4 and 6 chloro compounds that was resolved by C18-reverse phase high performance liquid chromatography. (author)

120

In vitro and in vivo release studies of fluorouracil acetic acid-dextran conjugates  

OpenAIRE

Fluorouracil acetic acid–dextran (FUD) conjugates were synthesized and its stability in buffer solution has been investigated previously in our laboratory. In this contribution, the in vitro and in vivo releases of FUD were investigated. The results revealed that no detectable 5-fluorouracil (5-FU, FU) found during in vitro and in vivo release studies. The in vitro release was dependent on both degree of substitution (DS) of 5-fluorouracil-1-acetic acid (5-FUA) in FUD and gastrointestin...

Hao, Aijun; Deng, Yingjie; Chen, Changlan; Zheng, Ying; Chen, Lijiang

2011-01-01

121

Preparation of 13C-labeled ceramide by acetic acid bacteria and its incorporation in mice  

OpenAIRE

We prepared 2-hydroxypalmitoyl-sphinganine (dihydroceramide) labeled with a stable isotope by culturing acetic acid bacteria with 13C-labeled acetic acid. The GC/MS spectrum of the trimethylsilyl derivative of 13C-labeled dihydroceramide gave molecular ions with an increased mass of 12–17 Da over that of nonlabeled dihydroceramide. The fragment ions derived from both sphinganine base and 2-hydroxypalmitate were confirmed to be labeled with the stable isotope in the spectrum. Therefore, 13C-...

Fukami, Hiroyuki; Tachimoto, Hideki; Kishi, Mikiya; Kaga, Takayuki; Waki, Hatsue; Iwamoto, Machiko; Tanaka, Yasukazu

2010-01-01

122

Acetic Acid Induces pH-Independent Cellular Energy Depletion in Salmonella enterica.  

Science.gov (United States)

Weak organic acids are widely used as preservatives and disinfectants in the food industry. Despite their widespread use, the antimicrobial mode of action of organic acids is still not fully understood. This study investigated the effect of acetic acid on the cell membranes and cellular energy generation of four Salmonella strains. Using a nucleic acid/protein assay, it was established that acetic acid did not cause leakage of intracellular components from the strains. A scanning electron microscopy study further confirmed that membrane disruption was not the antimicrobial mode of action of acetic acid. Some elongated Salmonella cells observed in the micrographs indicated a possibility that acetic acid may inhibit DNA synthesis in the bacterial cells. Using an ATP assay, it was found that at a neutral pH, acetic acid caused cellular energy depletion with an ADP/ATP ratio in the range between 0.48 and 2.63 (pbetter under acidic conditions (ADP/ATP ratio of 5.56±1.27; pfood products, such as chicken meat, which can buffer its pH. PMID:25562466

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

2015-03-01

123

Acetic acid modulates spike rate and spike latency to salt in peripheral gustatory neurons of rats.  

Science.gov (United States)

Sour and salt taste interactions are not well understood in the peripheral gustatory system. Therefore, we investigated the interaction of acetic acid and NaCl on taste processing by rat chorda tympani neurons. We recorded multi-unit responses from the severed chorda tympani nerve (CT) and single-cell responses from intact narrowly tuned and broadly tuned salt-sensitive neurons in the geniculate ganglion simultaneously with stimulus-evoked summated potentials to signal when the stimulus contacted the lingual epithelium. Artificial saliva served as the rinse and solvent for all stimuli [0.3 M NH(4)Cl, 0.5 M sucrose, 0.1 M NaCl, 0.01 M citric acid, 0.02 M quinine hydrochloride (QHCl), 0.1 M KCl, 0.003-0.1 M acetic acid, and 0.003-0.1 M acetic acid mixed with 0.1 M NaCl]. We used benzamil to assess NaCl responses mediated by the epithelial sodium channel (ENaC). The CT nerve responses to acetic acid/NaCl mixtures were less than those predicted by summing the component responses. Single-unit analyses revealed that acetic acid activated acid-generalist neurons exclusively in a concentration-dependent manner: increasing acid concentration increased response frequency and decreased response latency in a parallel fashion. Acetic acid suppressed NaCl responses in ENaC-dependent NaCl-specialist neurons, whereas acetic acid-NaCl mixtures were additive in acid-generalist neurons. These data suggest that acetic acid attenuates sodium responses in ENaC-expressing-taste cells in contact with NaCl-specialist neurons, whereas acetic acid-NaCl mixtures activate distinct receptor/cellular mechanisms on taste cells in contact with acid-generalist neurons. We speculate that NaCl-specialist neurons are in contact with type I cells, whereas acid-generalist neurons are in contact with type III cells in fungiform taste buds. PMID:22896718

Breza, Joseph M; Contreras, Robert J

2012-11-01

124

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

Directory of Open Access Journals (Sweden)

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

125

Regulation of Auxin Homeostasis and Gradients in Arabidopsis Roots through the Formation of the Indole-3-Acetic Acid Catabolite 2-Oxindole-3-Acetic Acid.  

Czech Academy of Sciences Publication Activity Database

Ro?. 25, ?. 10 (2013), s. 3858-3870. ISSN 1040-4651 R&D Projects: GA ?R(CZ) GAP305/11/0797 Institutional research plan: CEZ:AV0Z50380511 Keywords : BOX PROTEIN TIR1 * PLANT DEVELOPMENT * OXINDOLE-3- ACETIC ACID Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 9.575, year: 2013

P?n?ík, A.; Simonovik, B.; Petersson, S.V.; Hényková, Eva; Simon, Sibu; Greenham, K.; Zhang, Y.; Kowalczyk, M.; Estelle, M.; Zažímalová, Eva; Novák, Ond?ej; Sandberg, G.; Ljung, K.

2013-01-01

126

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

Energy Technology Data Exchange (ETDEWEB)

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

127

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

128

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

Directory of Open Access Journals (Sweden)

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

129

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

130

IMPROVED PROCESSES TO REMOVE NAPHTHENIC ACIDS  

Energy Technology Data Exchange (ETDEWEB)

In the second year of this project, we continued our effort to develop low temperature decarboxylation catalysts and investigate the behavior of these catalysts at different reaction conditions. We conducted a large number of dynamic measurements with crude oil and model compounds to obtain the information at different reaction stages, which was scheduled as the Task2 in our work plan. We developed a novel adsorption method to remove naphthenic acid from crude oil using naturally occurring materials such as clays. Our results show promise as an industrial application. The theoretical modeling proposed several possible reaction pathways and predicted the reactivity depending on the catalysts employed. From all of these studies, we obtained more comprehensive understanding about catalytic decarboxylation and oil upgrading based on the naphthenic acid removal concept.

Aihua Zhang; Qisheng Ma; Kangshi Wang, William A. Goddard, Yongchun Tang

2005-05-05

131

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

132

Microbiological preservation of cucumbers for bulk storage using acetic acid and food preservatives.  

Science.gov (United States)

Microbial growth did not occur when cucumbers were preserved without a thermal process by storage in solutions containing acetic acid, sodium benzoate, and calcium chloride to maintain tissue firmness. The concentrations of acetic acid and sodium benzoate required to ensure preservation were low enough so that stored cucumbers could be converted to the finished product without the need to wash out and discard excess acid or preservative. Since no thermal process was required, this method of preservation would be applicable for storing cucumbers in bulk containers. Acid tolerant pathogens died off in less than 24 h with the pH, acetic acid, and sodium benzoate concentrations required to assure the microbial stability of cucumbers stored at 30 degrees C. Potassium sorbate as a preservative in this application was not effective. Yeast growth was observed when sulfite was used as a preservative. PMID:19241560

Pérez-Díaz, I M; McFeeters, R F

2008-08-01

133

Formic and acetic acid: Valence threshold photoelectron and photoionisation total ion yield studies  

International Nuclear Information System (INIS)

Highlights: ? High-resolution threshold photoelectron spectrum of formic acid. ? High-resolution total photo-ion yield spectrum of formic acid. ? High-resolution threshold photoelectron spectrum of acetic acid. ? High-resolution total photo-ion yield spectrum of acetic acid. -- Abstract: The carboxylic acids (formic and acetic) have been studied using threshold photoelectron (TPE) and total photoion yield (TPIY) spectroscopies; simultaneously obtained spectra of formic acid (HCOOH) were recorded over the entire valence ionisation region from 11–21 eV at a resolution of ?12 meV. Higher resolution spectra (?6 meV) were also obtained in the energy region of the lowest two cationic states. Analysis of the TPE spectrum in this energy range agreed very favorably with the best available conventional photoelectron (PE) spectrum of formic acid. Autoionising Rydberg structure was observed in the TPIY spectrum of formic acid and is attributed primarily to the presence of the npa? ? 8a? Rydberg series converging on to the 32A? ionic state of formic acid. Preliminary results, at a resolution of ?8 meV, were obtained for acetic acid (CH3COOH) over the onset of the ionisation energy region. The TPE spectrum was found to be very similar to the best published photoelectron spectrum, but no Rydberg structure was observed in the TPIY spectrum.

134

Acetic Acid Activates the AMP-Activated Protein Kinase Signaling Pathway to Regulate Lipid Metabolism in Bovine Hepatocytes  

OpenAIRE

The effect of acetic acid on hepatic lipid metabolism in ruminants differs significantly from that in monogastric animals. Therefore, the aim of this study was to investigate the regulation mechanism of acetic acid on the hepatic lipid metabolism in dairy cows. The AMP-activated protein kinase (AMPK) signaling pathway plays a key role in regulating hepatic lipid metabolism. In vitro, bovine hepatocytes were cultured and treated with different concentrations of sodium acetate (neutralized acet...

Li, Xinwei; Chen, Hui; Guan, Yuan; Li, Xiaobing; Lei, Liancheng; Liu, Juxiong; Yin, Liheng; Liu, Guowen; Wang, Zhe

2013-01-01

135

Primary and secondary reduction products in irradiated acetic, monofluoroacetic and glycolic acid single crystal  

International Nuclear Information System (INIS)

Single crystals of acetic acid, monofluoroacetic acid, and glycolic acid have been irradiated at low temperature and investigated with ESR. The main purpose of the work was to obtain data for the structure and the reactions of the primary reduction products, i.e. the molecular anions. The anions of acetic acid and glycolic acid are stable at 77 K. The monofluoroacetic acid anion could not be observed even at 3 K, but a decay product tentatively assigned to the F-...CH2COOH adduct was detected. The glycolic acid anion decomposes by elimination of water to CH2COOH radical. The radical products CFH2 and C(OH)H2 were observed in monofluoroacetic and glycolic acid, respectively. They are probably formed by decomposition of the molecular cations. (author)

136

Two-dimensional hydrogen-bonded polymers in the crystal structures of the ammonium salts of phen-oxy-acetic acid, (4-fluoro-phen-oxy)acetic acid and (4-chloro-2-methyl-phen-oxy)acetic acid.  

Science.gov (United States)

The structures of the ammonium salts of phen-oxy-acetic acid, NH4 (+)·C8H6O3 (-), (I), (4-fluoro-phen-oxy)acetic acid, NH4 (+)·C8H5FO3 (-), (II), and the herbicidally active (4-chloro-2-methyl-phen-oxy)acetic acid (MCPA), NH4 (+)·C9H8ClO3 (-)·0.5H2O, (III) have been determined. All have two-dimensional layered structures based on inter-species ammonium N-H?O hydrogen-bonding associations, which give core substructures consisting primarily of conjoined cyclic motifs. The crystals of (I) and (II) are isomorphous with the core comprising R 1 (2)(5), R 1 (2)(4) and centrosymmetric R 4 (2)(8) ring motifs, giving two-dimensional layers lying parallel to (100). In (III), the water mol-ecule of solvation lies on a crystallographic twofold rotation axis and bridges two carboxyl O atoms in an R 4 (4)(12) hydrogen-bonded motif, creating two R 4 (3)(10) rings, which together with a conjoined centrosymmetric R 4 (2)(8) ring incorporating both ammonium cations, generate two-dimensional layers lying parallel to (100). No ?-? ring associations are present in any of the structures. PMID:25552984

Smith, Graham

2014-12-01

137

Two-dimensional hydrogen-bonded polymers in the crystal structures of the ammonium salts of phen­oxy­acetic acid, (4-fluoro­phen­oxy)acetic acid and (4-chloro-2-methyl­phen­oxy)acetic acid  

Science.gov (United States)

The structures of the ammonium salts of phen­oxy­acetic acid, NH4 +·C8H6O3 ?, (I), (4-fluoro­phen­oxy)acetic acid, NH4 +·C8H5FO3 ?, (II), and the herbicidally active (4-chloro-2-methyl­phen­oxy)acetic acid (MCPA), NH4 +·C9H8ClO3 ?·0.5H2O, (III) have been determined. All have two-dimensional layered structures based on inter-species ammonium N—H?O hydrogen-bonding associations, which give core substructures consisting primarily of conjoined cyclic motifs. The crystals of (I) and (II) are isomorphous with the core comprising R 1 2(5), R 1 2(4) and centrosymmetric R 4 2(8) ring motifs, giving two-dimensional layers lying parallel to (100). In (III), the water mol­ecule of solvation lies on a crystallographic twofold rotation axis and bridges two carboxyl O atoms in an R 4 4(12) hydrogen-bonded motif, creating two R 4 3(10) rings, which together with a conjoined centrosymmetric R 4 2(8) ring incorporating both ammonium cations, generate two-dimensional layers lying parallel to (100). No ?–? ring associations are present in any of the structures. PMID:25552984

Smith, Graham

2014-01-01

138

Uncatalyzed reaction of silyl ketene acetals with oxalyl chloride: a straightforward preparation of symmetrical pulvinic acids.  

Science.gov (United States)

[reaction: see text] Several natural pulvinic acids were synthesized. Silyl ketene acetals derived from methyl arylacetates (4 equiv) reacted with oxalyl chloride at -78 degrees C, without the need of adding a catalyst. After treatment of the crude diketones with DBU and acidification with hydrochloric acid, symmetrical pulvinic acids methyl esters were obtained. Saponification of the methyl esters afforded the corresponding pulvinic acids in 60-70% overall yields from oxalyl chloride. PMID:15704989

Heurtaux, Benoît; Lion, Claude; Le Gall, Thierry; Mioskowski, Charles

2005-02-18

139

IMPROVED PROCESSES TO REMOVE NAPHTHENIC ACIDS  

Energy Technology Data Exchange (ETDEWEB)

In the first year of this project, we have established our experimental and theoretical methodologies for studies of the catalytic decarboxylation process. We have developed both glass and stainless steel micro batch type reactors for the fast screening of various catalysts with reaction substrates of model carboxylic acid compounds and crude oil samples. We also developed novel product analysis methods such as GC analyses for organic acids and gaseous products; and TAN measurements for crude oil. Our research revealed the effectiveness of several solid catalysts such as NA-Cat-1 and NA-Cat-2 for the catalytic decarboxylation of model compounds; and NA-Cat-5{approx}NA-Cat-9 for the acid removal from crude oil. Our theoretical calculations propose a three-step concerted oxidative decarboxylation mechanism for the NA-Cat-1 catalyst.

Aihua Zhang; Qisheng Ma; William A. Goddard; Yongchun Tang

2004-04-28

140

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

141

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

OpenAIRE

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 v...

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

2014-01-01

142

The fate of acetic acid during glucose co-metabolism by the spoilage yeast Zygosaccharomyces bailii.  

Science.gov (United States)

Zygosaccharomyces bailii is one of the most widely represented spoilage yeast species, being able to metabolise acetic acid in the presence of glucose. To clarify whether simultaneous utilisation of the two substrates affects growth efficiency, we examined growth in single- and mixed-substrate cultures with glucose and acetic acid. Our findings indicate that the biomass yield in the first phase of growth is the result of the weighted sum of the respective biomass yields on single-substrate medium, supporting the conclusion that biomass yield on each substrate is not affected by the presence of the other at pH 3.0 and 5.0, at least for the substrate concentrations examined. In vivo(13)C-NMR spectroscopy studies showed that the gluconeogenic pathway is not operational and that [2-(13)C]acetate is metabolised via the Krebs cycle leading to the production of glutamate labelled on C(2), C(3) and C(4). The incorporation of [U-(14)C]acetate in the cellular constituents resulted mainly in the labelling of the protein and lipid pools 51.5% and 31.5%, respectively. Overall, our data establish that glucose is metabolised primarily through the glycolytic pathway, and acetic acid is used as an additional source of acetyl-CoA both for lipid synthesis and the Krebs cycle. This study provides useful clues for the design of new strategies aimed at overcoming yeast spoilage in acidic, sugar-containing food environments. Moreover, the elucidation of the molecular basis underlying the resistance phenotype of Z. bailii to acetic acid will have a potential impact on the improvement of the performance of S. cerevisiae industrial strains often exposed to acetic acid stress conditions, such as in wine and bioethanol production. PMID:23285028

Rodrigues, Fernando; Sousa, Maria João; Ludovico, Paula; Santos, Helena; Côrte-Real, Manuela; Leão, Cecília

2012-01-01

143

Comparative analysis of acetic and citric acid on internal milieu of broiler chickens  

Directory of Open Access Journals (Sweden)

Full Text Available Normal 0 21 false false false CS JA X-NONE The aim of the present study was to analyse the effect of two organic acids (acetic and citric acid inclusion on serum parameters and the level of antioxidant status of broiler chickens. Some organic acidifiers reduce the growth of many intestinal bacteria, reduce intestinal colonisation and reduce infectious processes, decrease inflammatory processes at the intestinal mucosa, increase villus height and function of secretion, digestion and absorption of nutrients. Broiler chickens hybrid Ross 308 (n=180 were divided into 3 groups: one control (C and two experimental groups (E1, E2. Experimental animals received acetic and citric acid per os in water in single dose 0.25% for 42 days. After 42 days of feeding blood samples were collected (n=10 in each group. Significant decrease of serum triglycerides in citric acid group when compared with the control group was recorded. Acetic acid administration resulted in increased sodium level. Significant increase of albumin content in both experimental groups and increase of bilirubin content in citric group was recorded. Acids administration had no significant effect on other serum and antioxidant parameters. Acetic and citric acid had no harmful influenced on internal milieu of broiler chickens. The research on the field of organic acid will be worthy of further investigation.

Marcela Capcarova

2014-02-01

144

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

145

Silicotungstic Acid Modified Bentonite: An Efficient Catalyst for Synthesis of Acetal Derivatives of Aldehydes and Ketones  

OpenAIRE

Acetals and ketals are among the important materials of organic synthesis and as protecting agent of carbonyl functionality. A milder, efficient and green synthesis of acetals and ketals has been developed using Silicotungstic acid modified Bentonite (STA-Ben) as a catalyst. STA-Ben has been synthesized and characterized by various analytical techniques. It has been found to be an efficient and reusable catalyst for the synthesis of acetyl derivatives in excellent yield...

Reshu Chaudhary; Monika Datta

2013-01-01

146

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

147

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

Directory of Open Access Journals (Sweden)

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

148

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

149

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

Directory of Open Access Journals (Sweden)

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

150

Effect of acetic acid on wet patterning of copper/molybdenum thin films in phosphoric acid solution  

International Nuclear Information System (INIS)

Copper metallization is a key issue for high performance thin film transistor (TFT) technology. A phosphoric acid based copper etchant is a potentially attractive alternative to the conventional hydrogen peroxide based etchant due to its longer-life expectancy time and higher stability in use. In this paper, it is shown that amount of the acetic acid in the phosphoric based copper etchant plays an important role in controlling the galvanic reaction between the copper and the molybdenum. As the concentration of acetic acid in the phosphoric mixture solution increased from 0 M to 0.4 M, the measured galvanic current density dropped from 32 mA/cm2 to 26 mA/cm2, indicating that the acetic acid induces the lower galvanic reaction between the copper and the molybdenum in the solution. From the XPS analysis, with the addition of the acetic acid, the thickness of the protective MoO2 passive film covering the molybdenum surface grew and the dissolution rate of the molybdenum thin film decreased. However, the dissolution rate of the copper thin film increased as the concentration of acetic acid in the mixture solution increased.

151

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

Directory of Open Access Journals (Sweden)

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

2013-02-01

152

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

Directory of Open Access Journals (Sweden)

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

153

Conversion of the refractory ammonia and acetic acid in catalytic wet air oxidation of animal byproducts.  

Science.gov (United States)

Wet air oxidation (WAO) and catalytic wet air oxidation (CWAO) of slaughtered animal byproducts (ABPs) were investigated. Two step experiment was carried out consisting of a non-catalysed WAO run followed by a CWAO run at 170-275 degrees C, 20 MPa, and reaction time 180 min. The WAO (1st step) of sample (5 g/L total organic carbon (TOC)) yielded (82.0 +/- 4)% TOC removal and (78.4 +/- 13.2)% conversion of the initial organic-N into NH4(+)-N. Four metal catalysts (Pd, Pt, Rh, Ru) supported over alumina have been tested in catalytic WAO (2nd step) at elevated pH to enhance ammonia conversion and organic matter removal, particularly acetic acid. It was found that the catalysts Ru, Pt, and Rh had significant effects on the TOC removal (95.1%, 99.5% and 96.7%, respectively) and on the abatement of ammonia (93.4%, 96.7% and 96.3%, respectively) with high nitrogen selectivity. The catalyst Pd was found to have the less activity while Pt had the best performance. The X-Ray diffraction analysis showed that the support of catalyst was not stable under the experimental conditions since it reacted with phosphate present in solution. Nitrite and nitrate ions were monitored during the oxidation reaction and it was concluded that CWAO of ammonia in real waste treatment framework was in good agreement with the results obtained from the literature for ideal solutions of ammonia. PMID:21520823

Fontanier, Virginie; Zalouk, Sofiane; Barbati, Stéphane

2011-01-01

154

Synthesis and Antiradical/Antioxidant Activities of Caffeic Acid Phenethyl Ester and Its Related Propionic, Acetic, and Benzoic Acid Analoguesc  

OpenAIRE

Caffeic acid phenethyl ester (CAPE) is a bioactive component isolated from propolis. A series of CAPE analogues was synthesized and their antiradical/antioxidant effects analyzed. The effect of the presence of the double bond and of the conjugated system on the antioxidant effect is evaluated with the analogues obtained from 3-(3,4-dihydroxyphenyl) propanoic acid. Those obtained from 2-(3,4-dihydroxyphenyl) acetic acid and 3,4-dihydroxybenzoic acid allow the evaluation of the effect of the pr...

Mohamed Touaibia; Surette, Marc E.; He?bert, Martin J. G.; Pare?, Aure?lie F.; Jacques Jean-François; Leblanc, Luc M.

2012-01-01

155

Regulation of auxin homeostasis and gradients in Arabidopsis roots through the formation of the indole-3-acetic acid catabolite 2-oxindole-3-acetic acid.  

Science.gov (United States)

The native auxin, indole-3-acetic acid (IAA), is a major regulator of plant growth and development. Its nonuniform distribution between cells and tissues underlies the spatiotemporal coordination of many developmental events and responses to environmental stimuli. The regulation of auxin gradients and the formation of auxin maxima/minima most likely involve the regulation of both metabolic and transport processes. In this article, we have demonstrated that 2-oxindole-3-acetic acid (oxIAA) is a major primary IAA catabolite formed in Arabidopsis thaliana root tissues. OxIAA had little biological activity and was formed rapidly and irreversibly in response to increases in auxin levels. We further showed that there is cell type-specific regulation of oxIAA levels in the Arabidopsis root apex. We propose that oxIAA is an important element in the regulation of output from auxin gradients and, therefore, in the regulation of auxin homeostasis and response mechanisms. PMID:24163311

Pencík, Ales; Simonovik, Biljana; Petersson, Sara V; Henyková, Eva; Simon, Sibu; Greenham, Kathleen; Zhang, Yi; Kowalczyk, Mariusz; Estelle, Mark; Zazímalová, Eva; Novák, Ondrej; Sandberg, Göran; Ljung, Karin

2013-10-01

156

Pitting Corrosion of Tin by Acetate Anion in Acidic Media  

Directory of Open Access Journals (Sweden)

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

157

STUDY OF THE INTERACTIONS BETWEEN COPPER(II) ACETATE MONOHYDRATE AND OROTIC ACID AND OROTATE LIGANDS  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english Different complexes by reacting copper(II) acetate monohydrate with orotic acid and orotate as ligands were prepared. These compounds were characterized by elemental analysis, spectroscopy, and thermal analysis. It is suggested that in both compounds, the Cu2(acetate)4 suffers the break of both acet [...] ate groups by a substitution of orotic or orotate ligands, increasing the Cu-Cu distance. It was corroborated by the magnetic moment values of 1.65 and 1.82 B.M for these compounds. The anion orotato(-1) coordinates through the carboxylic acid and the orotic acid by the oxygen from exocyclic C=O. Semiempirical PM3 calculations for both compounds were also carried out.

GLORIA V, SEGUEL; BERNABÉ L, RIVAS; CÉSAR, PAREDES.

158

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

159

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

160

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 concentrations (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

2011-02-01

161

Inhibition of Methanogenesis from Acetate in Granular Sludge by Long-Chain Fatty Acids  

OpenAIRE

The effect of four saturated long-chain fatty acids (caprylic, capric, lauric, and myristic) and one unsaturated long-chain fatty acid (oleic) on the microbial formation of methane from acetate was investigated in batch anaerobic toxicity assays. The tests were carried out with granular sludge from an upflow anaerobic sludge bed reactor. In this sludge, Methanothrix spp. are the predominant acetoclastic methanogens. Lauric acid appeared to be the most versatile inhibitor: inhibition started a...

Koster, I. W.; Cramer, A.

1987-01-01

162

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

163

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

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 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

164

Improved Processes to Remove Naphthenic Acids  

Energy Technology Data Exchange (ETDEWEB)

In the past three years, we followed the work plan as we suggested in the proposal and made every efforts to fulfill the project objectives. Based on our large amount of creative and productive work, including both of experimental and theoretic aspects, we received important technical breakthrough on naphthenic acid removal process and obtained deep insight on catalytic decarboxylation chemistry. In detail, we established an integrated methodology to serve for all of the experimental and theoretical work. Our experimental investigation results in discovery of four type effective catalysts to the reaction of decarboxylation of model carboxylic acid compounds. The adsorption experiment revealed the effectiveness of several solid materials to naphthenic acid adsorption and acidity reduction of crude oil, which can be either natural minerals or synthesized materials. The test with crude oil also received promising results, which can be potentially developed into a practical process for oil industry. The theoretical work predicted several possible catalytic decarboxylation mechanisms that would govern the decarboxylation pathways depending on the type of catalysts being used. The calculation for reaction activation energy was in good agreement with our experimental measurements.

Aihua Zhang; Qisheng Ma; Kangshi Wang; Yongchun Tang; William A. Goddard

2005-12-09

165

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

Directory of Open Access Journals (Sweden)

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

166

PRODUCTION OF CAROTENOIDS (ANTIOXIDANTS/ COLOURANT) IN SPIRULINA PLATENSIS IN RESPONSE TO INDOLE ACETIC ACID (IAA)  

OpenAIRE

The Carotenoid compounds (antioxidants) synthesis in spirulina platennsis was studied in vitro under the influence of the Indole Acetic Acid (IAA). Spirulina platensis is grown in Zarrouks medium supplemented with different concentration of Indole Acetic Acid ( 1?g/ml–10?g/ml ). The gradual increase in the total Carotenoidscontent was recorded from 1- 6 ?g/ml of IAA. Inhibition in the synthesis of Carotenoids compounds was noticed in 7?g/ml-10?g/ml the similar trend was also observed w...

Munawer Khan Mohammed,; Mazharuddin Khan Mohd.

2011-01-01

167

Acetic acid bacteria and the production and quality of wine vinegar.  

Science.gov (United States)

The production of vinegar depends on an oxidation process that is mainly performed by acetic acid bacteria. Despite the different methods of vinegar production (more or less designated as either "fast" or "traditional"), the use of pure starter cultures remains far from being a reality. Uncontrolled mixed cultures are normally used, but this review proposes the use of controlled mixed cultures. The acetic acid bacteria species determine the quality of vinegar, although the final quality is a combined result of technological process, wood contact, and aging. This discussion centers on wine vinegar and evaluates the effects of these different processes on its chemical and sensory properties. PMID:24574887

Mas, Albert; Torija, María Jesús; García-Parrilla, María del Carmen; Troncoso, Ana María

2014-01-01

168

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

169

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

Directory of Open Access Journals (Sweden)

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

170

The conjugated auxin indole-3-acetic acid-aspartic acid promotes plant disease development.  

Science.gov (United States)

Auxin is a pivotal plant hormone that regulates many aspects of plant growth and development. Auxin signaling is also known to promote plant disease caused by plant pathogens. However, the mechanism by which this hormone confers susceptibility to pathogens is not well understood. Here, we present evidence that fungal and bacterial plant pathogens hijack the host auxin metabolism in Arabidopsis thaliana, leading to the accumulation of a conjugated form of the hormone, indole-3-acetic acid (IAA)-Asp, to promote disease development. We also show that IAA-Asp increases pathogen progression in the plant by regulating the transcription of virulence genes. These data highlight a novel mechanism to promote plant susceptibility to pathogens through auxin conjugation. PMID:22374398

González-Lamothe, Rocío; El Oirdi, Mohamed; Brisson, Normand; Bouarab, Kamal

2012-02-01

171

Polarographic study of Cd(2), Pb(2), Hg(1) in anhydrous acetic acid  

International Nuclear Information System (INIS)

Anhydrous acetic acid is a solvent which can be compared to water as far as its behaviour towards acid-base reactions is concerned. It is in fact, like water both a proton acceptor (basic) - and as such it can provoke the dissociation of acids - and a proton donor (acid). This amphoteric behaviour is characterized by the equilibrium: 2 H O Ac ? Ac OH2+ + Ac O- with Ki = |Ac O H2|+ |Ac O-| = 10-14.5 analogue to 2 H2O ? H3O+ + HO- with Ki = |H3O+| |HO-| = 10-14 The acid-base reactions can in principle be characterized by a pH scale based on a definition similar to that for the pH scale in aqueous solutions. The essential difference however between aqueous and acetic acid solutions is due to the fact that acetic acid has a low dielectric constant. ? = 6.1 (at 25 deg. C) The ions therefore remain associated, almost completely, in the form of ion-pairs produced as a result of the strong electrostatic interactions. This phenomenon requires us to modify the reasoning usually applied to aqueous solutions. The new general methods of reasoning have been established and discussed by G. CHARLOT and B. TREMILLON. We will make use of them for the particular case under consideration. In the first part, we have employed the polarographic method for the study of the acetic complexes of two elements: cadmium(II) and lead (II). In the second part we have tried to show that mercurous halides are formed in acetic acid; we have attempted to determine their stability. (author)

172

Chapter 21 Architecture of Hydrates and Local Structure of Acetic Acid Aqueous Solution  

Science.gov (United States)

The protonation and deprotonation phenomena and molecular association of solute molecule with water via intermolecular hydrogen bonding forming various hydration compounds are very common in aqueous solution and in biological cell in nature. In the aqueous solution, more complicated type of hydrogen bond, hydrogen-bonding rings, various kinds of hydration compounds (hydrates), and even hydrogen-bonding network can be expected. The nature of hydrogen bonding, the bonds networking, the rule in architecture of larger hydration compounds, deprotonation of acetic acid in solution, stability of the hydrated proton, and the local structure of its aqueous solution are the most fundamental problems to understanding solute molecule living style in aqueous solution. Hydrogen-bonding rings and network in the multi-hydrates of acetic acid monomer have been investigated by ab initio calculations, and ab initio molecular dynamics (CPMD) simulations on acetic acid monomer-water system were also performed to explore the local structure of acetic acid aqueous solution. More than hundreds of multi-hydrates have been selected as candidates during our calculations. The structural optimizations and energy calculations have been performed at the MP2/6-31+g (d, p) and MP4/6-31+g (d, p) levels which are adequate for our large hydrates calculations with reliable results and reasonable cost as we stated in the Section 2. The most stable structure of the smallest hydration compound of acetic acid monomer, i.e., acetic acid water dimer, has a four-membered head-on ring with the smallest dipole moment. To verify the existence of it, the infrared spectra experiment data were collected in the dilute CCl4/HAc and CCl4/H2O ratio condition. The hydroxyl (O-H) stretching vibrations in molecules of water, acetic acid, and the dimer are distinguished, for the dissolved species are isolated from each other by surrounded solvent molecules CCl4. The calculated and measured vibration frequencies are almost lain in line with 0.872 scaling. The four-, five-, and six-membered head-on rings are the most favorable in the small multi-hydrates with a stable planar structure and the side-on ring with a weak hydrogen-bonding interaction of C-H...Ow-H. The six-membered ring is most important in the large multi-hydrates and in the local structure of dilute solution also verified by our CPMD simulations. A larger ring of or more than seven-membered could no longer maintain the planar structure. Larger multi-hydrates of acetic acid monomer could be constructed from these basic building blocks. The strength order for the five kinds of bonds is in the descending order as C-O-H...Ow-H>Ow-H...Ow-H>CO...H-Ow>Ow-H...Oa-H>>C-H...Ow-H. The three hydroxyl bonds O-H in the hydrated proton could be divided into two types: one of the hydroxyl bonds is hydrogen bonded to the deprotonated oxygen of the acetic acid, other two to waters in the hydrate. The larger the RO-H becomes, the smaller the RO...H and the stronger the associated hydrogen bond are. The hydrated proton is stable and liberated from the deprotonated acetic acid in the large multi-hydrate with more complicit head-on ring. In small hydrates, the protonating hydrogen is shared partly by the acetic acid.

Pu, Liang; Wang, Qing; Zhang, Yong; Miao, Qiang; Kim, Yang-Soo; Zhang, Zhibing

173

SYNTHESIS AND CHARACTERIZATION OF Zn(II) COMPLEX WITH THE ACETATE AND OROTIC ACID MK LIGANDS  

Scientific Electronic Library Online (English)

Full Text Available Semi-empirical calculations were used to characterize the orotic acid structure. The structures optimised using the PM3, AM1, and CNDO methods were compared with the crystallographic data. Orotic acid is a polydentate ligand due to the net charge on the atoms from the functional group. A compound wa [...] s synthesized by reacting orotic acid with zinc acetate dihydrated in a neutral and non-aqueous media. This compound was characterized by elemental analysis, spectroscopy, and thermal analysis. The orotic acid replaces water molecules from zinc acetate dihydrate and coordinates through an exo-cyclic oxygen. Based on the probable structure, PM3 semi-empirical calculations of the complex of Zn(II) were performed. The semi-empirical calculations suggest that the orotic acid coordinated through C2=O group, where acetate groups maintained the bidentate coordination and the Zn- H3Or distance is greater than that the Zn- H2O distance for the Zn(II) acetate dihydrate.

GLORIA V, SEGUEL; BERNABÉ L, RIVAS; CÉSAR, PAREDES.

174

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

International Nuclear Information System (INIS)

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.

175

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

OpenAIRE

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

176

Lipidomic profiling of Saccharomyces cerevisiae and Zygosaccharomyces bailii reveals critical changes in lipid composition in response to acetic acid stress.  

Science.gov (United States)

When using microorganisms as cell factories in the production of bio-based fuels or chemicals from lignocellulosic hydrolysate, inhibitory concentrations of acetic acid, released from the biomass, reduce the production rate. The undissociated form of acetic acid enters the cell by passive diffusion across the lipid bilayer, mediating toxic effects inside the cell. In order to elucidate a possible link between lipid composition and acetic acid stress, the present study presents detailed lipidomic profiling of the major lipid species found in the plasma membrane, including glycerophospholipids, sphingolipids and sterols, in Saccharomyces cerevisiae (CEN.PK 113_7D) and Zygosaccharomyces bailii (CBS7555) cultured with acetic acid. Detailed physiological characterization of the response of the two yeasts to acetic acid has also been performed in aerobic batch cultivations using bioreactors. Physiological characterization revealed, as expected, that Z. bailii is more tolerant to acetic acid than S. cerevisiae. Z. bailii grew at acetic acid concentrations above 24 g L(-1), while limited growth of S. cerevisiae was observed after 11 h when cultured with only 12 g L(-1) acetic acid. Detailed lipidomic profiling using electrospray ionization, multiple-reaction-monitoring mass spectrometry (ESI-MRM-MS) showed remarkable changes in the glycerophospholipid composition of Z. bailii, including an increase in saturated glycerophospholipids and considerable increases in complex sphingolipids in both S. cerevisiae (IPC 6.2×, MIPC 9.1×, M(IP)2C 2.2×) and Z. bailii (IPC 4.9×, MIPC 2.7×, M(IP)2C 2.7×), when cultured with acetic acid. In addition, the basal level of complex sphingolipids was significantly higher in Z. bailii than in S. cerevisiae, further emphasizing the proposed link between lipid saturation, high sphingolipid levels and acetic acid tolerance. The results also suggest that acetic acid tolerance is associated with the ability of a given strain to generate large rearrangements in its lipid profile. PMID:24023914

Lindberg, Lina; Santos, Aline Xs; Riezman, Howard; Olsson, Lisbeth; Bettiga, Maurizio

2013-01-01

177

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)

178

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.

1998-05-01

179

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

OpenAIRE

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 wate...

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

2011-01-01

180

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

181

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; Paul, E. A.

1971-01-01

182

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.

Wong, M.; Woodley, John

2010-01-01

183

Wet Air Oxidation of Acetic Acid Catalyzed by Platinum Supported over Cerium (Mixed) Oxide.  

Czech Academy of Sciences Publication Activity Database

Bratislava : Slovak Society of Chemical Engineering, 2008 - (Markoš, J.), s. 257 ISBN 978-80-227-2903-1. [35th International Conference of Slovak Society of Chemical Engineering. Tatranské Matliare (SK), 26.05.2008-30.05.2008] Institutional research plan: CEZ:AV0Z40720504 Keywords : catalysts for wet air oxidation * acetic acid * platinum Subject RIV: CF - Physical ; Theoretical Chemistry

Mikulová, Jana; Rossignol, S.; Barbier Jr., J.

184

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

185

Molecular Cloning and Biochemical Characterization of Indole-3-acetic Acid Methyltransferase from Poplar (Populus trichocarpa)  

Science.gov (United States)

Indole-3-acetic acid (IAA) is the most active endogenous auxin involved in various physiological processes in higher plants. Concentrations of IAA in plant tissues are regulated at multiple levels including de novo biosynthesis, degradation, and conjugation/deconjugation. In this paper, we report id...

186

Interaction of dilute acetic acid with lead-containing vitreous surfaces  

International Nuclear Information System (INIS)

Reactions of acetic acid with lead-containing vitreous glazes composed of 10 percent kaolin clay and 90 percent of various oxides including B2O3 and ZrO2 were investigated. The extraction procedure was that specified in ASTMC-738-72. The amount of lead extracted from surfaces of the glazes is presented in plots of lead release vs time

187

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

Directory of Open Access Journals (Sweden)

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

188

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 9 mol% 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

189

Radiolysis of aqueous solutions of acetic acid in the presence of Na-montmorillonite  

Science.gov (United States)

The gamma-irradiation of 0.8 mol dm-3 aqueous, oxygen-free acetic acid solutions was investigated in the presence or absence of Na-montmorillonite. H2, CH4, CO, CO2, and several polycarboxylic acids were formed in all systems. The primary characteristics observed in the latter system were: (1) Higher yield of the decomposition of acetic acid; (2) Lower yield of the formation of polycarboxylic acids; (3) No effect on the formation of methane; (4) Higher yield of the formation of carbon dioxide; and (5) The reduction of Fe3+ in the octahedral sites of Na-montmorillonite. A possible reaction scheme was proposed to account for the observed changes. The results are important in understanding heterogeneous processes in radiation catalysis and might be significant to prebiotic chemistry.

Navarro-Gonzalez, R.; Negron-Mendoza, A.; Ramos, S.; Ponnamperuma, C.

1990-01-01

190

PREPARATION AND CHARACTERIZATION OF ACETIC ACID LIGNIN-BASED EPOXY BLENDS  

OpenAIRE

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 epo...

Fangeng Chen,; Pan Feng,

2012-01-01

191

A mutation affecting the synthesis of 4-chloroindole-3-acetic acid  

OpenAIRE

Traditionally, schemes depicting auxin biosynthesis in plants have been notoriously complex. They have involved up to four possible pathways by which the amino acid tryptophan might be converted to the main active auxin, indole-3-acetic acid (IAA), while another pathway was suggested to bypass tryptophan altogether. It was also postulated that different plants use different pathways, further adding to the complexity. In 2011, however, it was suggested that one of the four tryptophan-dependent...

Ross, John J.; Tivendale, Nathan D.; Davidson, Sandra E.; Reid, James B.; Davies, Noel W.; Quittenden, Laura J.; Smith, Jason A.

2012-01-01

192

TGA-FTIR study of the vapors released by triethylamine-acetic acid mixtures  

OpenAIRE

Proprietary mixtures of amines and carboxylic acids are used as volatile corrosion inhibitors (VCIs) for the protection of iron and steel components against atmospheric corrosion. This study was focused on the nature of the vapors they release. VCI model compounds comprising mixtures of triethylamine and acetic acid were studied using thermogravimetric analysis coupled with Fourier-transform infrared spectroscopy (TGA–FTIR) at 50 ?C. As vaporization progressed, the composition...

Nhlapo, Nontete Susan; Focke, Walter Wilhelm; Vuorinen, Eino

2012-01-01

193

Supported Ionic Liquid Phase (SILP) Catalysis for the Production of Acetic acid by Methanol Carbonylation  

DEFF Research Database (Denmark)

The work presented here is focused on the development of a new reaction process. It applies Supported Ionic Liquid Phase (SILP) catalysis to a specific reaction. By reacting methanol and carbon monoxide over a rhodium catalyst, acetic acid can be formed. This reaction is important on a large scale industrially, with millions of tonnes of acetic acid being produced annually. Acetic acid is an important precursor for making adhesives, plastics and fabrics. By using the SILP concept we are able to carry out the reaction in a continuous system, allowing a steady production of acetic acid without having to stop and re-start the reaction. This sort of continuous flow reaction is a subject of great research effort in recent years as it is more sustainable (and in some cases financially viable) that the current method of carrying out chemical reactions in large size batch reactions The project started right at the beginning with the construction of a suitable test reactor, then followed by the synthesis and testing of all the catalysts reported. A variety of nitrogen based ionic liquids were initially tested, giving good results and stability in the system. Later a number of phosphonium based salts were tested (these were no longer classified as ionic liquids due to melting points above 100?C). The phosphonium salts showed even better activity in the system compared to the ionic liquids. Overall the work has shown that this process for the manufacture of acetic acid is viable industrially. This is backed up by the construction and operation of a pilot plant by Wacker Chemie AG in Munich.

Hanning, Christopher William

2012-01-01

194

Concentrations of volatile fatty acids and acetate production rates in the forestomachs of grazing camels.  

Science.gov (United States)

1. Concentration profiles of volatile fatty acids (VFA), fluid volumes and turnover rates, and acetate production rates were measured in two different seasons in the forestomachs of four fistulated dromedary camels grazing in the Kenyan thornbush savannah. 2. VFA profiles and average concentrations were similar under both feeding conditions but, due to a smaller fluid turnover, VFA outflow to lower gastric sections in the dry season was reduced by almost 50%. 3. The mean acetate production rate fell from 2234 mmol/hr in the green season to 816 mmol/hr in the dry season, i.e. by approximately 64%. PMID:2776433

Höller, H; Breves, G; Lechner-Doll, M; Schulze, E

1989-01-01

195

Carbohydrate-based polyesters made from bicyclic acetalized galactaric acid  

OpenAIRE

The dimethyl ester of 2,3:4,5-di-O-methylene-galactaric acid (Galx) was made to react in the melt with 1,n-alkanediols HO(CH2)nOH containing even numbers of methylenes (n from 6 to 12) to produce linear polycyclic polyesters. Two sets of poly(alkylene 2,3:4,5-di-O-methylenegalactarate) polyesters (PE-nGalx) with weight-average molecular weights in the ?5000 - 10000 and ?35000 - 45000 ranges were obtained using TBT and DBTO catalysts, respectively. For comparative purposes a set of poly...

Lavilla Aguilar, Cristina; Alla Bedahnane, Abdelilah; Marti?nez Ilarduya Sa?ez Asteasu, Domingo Antxon; Benito, Elena; Garci?a Marti?n, Maria Gracia; Galbis Pe?rez, Juan Antonio; Mun?oz Guerra, Sebastia?n

2011-01-01

196

Genomic Expression Program Involving the Haa1p-Regulon in Saccharomyces cerevisiae Response to Acetic Acid  

Science.gov (United States)

Abstract The alterations occurring in yeast genomic expression during early response to acetic acid and the involvement of the transcription factor Haa1p in this transcriptional reprogramming are described in this study. Haa1p was found to regulate, directly or indirectly, the transcription of approximately 80% of the acetic acid-activated genes, suggesting that Haa1p is the main player in the control of yeast response to this weak acid. The genes identified in this work as being activated in response to acetic acid in a Haa1p-dependent manner include protein kinases, multidrug resistance transporters, proteins involved in lipid metabolism, in nucleic acid processing, and proteins of unknown function. Among these genes, the expression of SAP30 and HRK1 provided the strongest protective effect toward acetic acid. SAP30 encode a subunit of a histone deacetylase complex and HRK1 encode a protein kinase belonging to a family of protein kinases dedicated to the regulation of plasma membrane transporters activity. The deletion of the HRK1 gene was found to lead to the increase of the accumulation of labeled acetic acid into acid-stressed yeast cells, suggesting that the role of both HAA1 and HRK1 in providing protection against acetic acid is, at least partially, related with their involvement in the reduction of intracellular acetate concentration. PMID:20955010

Becker, Jorg D.; Sá-Correia, Isabel

2010-01-01

197

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

198

Acetic acid production from marine algae. Progress report No. 1, July 1--September 30, 1977  

Energy Technology Data Exchange (ETDEWEB)

Progress is reported in research designed to develop an economically competitive process for producing acetic acid from biomass for the purpose of sparing petroleum for other uses, to evaluate marine algae as a potential source of biomass, and to document the feasibility of running fermentations in fixed packed bed fermenters. It was demonstrated that marine algae can be fermented to acetic acid. Initial rates of up to 168 meq/1 day were observed. These rates are substantially in excess of the 47 meq/1 day used in the economic projections. Also, when using marine algae as a substrate, acid levels were generated equivalent to the highest reported with other substrates. It was also demonstrated that a 4-foot fixed packet bed fermenter may be operated with marine algae as a substrate at 20 percent solids or 200 meq/1.

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

1977-10-14

199

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

200

Observation of SERS of picolinic acid and nicotinic acid using cellulose acetate films doped with Ag fine particles  

Science.gov (United States)

Surface enhanced Raman (SER) spectra of picolinic acid and nicotinic acid were observed using cellulose acetate (CA) films doped with Ag fine particles. The spectra obtained match those reported for silver colloids though some differences in SER band intensity were observed. The ease of preparation and handling of the CA film method renders it more useful than the colloid method for the observation of SER spectra.

Imai, Yoshika; Kurokawa, Yoichi; Hara, Masaru; Fukushima, Michiko

1997-10-01

201

[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

202

Bactericidal effect of ADP and acetic acid on Bacillus subtilis.  

Science.gov (United States)

Bacillus subtilis is a ubiquitous soil bacterium used for measuring the beta-lysin activity and in other bioassays. We observed a complete bactericidal effect of ADP on B. subtilis at concentrations of 50-100 microM at pH values 17.4 microM and similar pH values. ATP, adenosine, and HCl were not bactericidal. We used BCECF-AM, a pH-sensitive probe, and found that the killing of B. subtilis was due to a change in the intracellular pH caused by the passage across the cell membrane of these weak organic acids when incubated with B. subtilis at pH values near the pK. More experiments are needed to determine the biological meaning of these in vitro findings. PMID:8939804

Asensi, V; Parra, F; Fierer, J; Valle, E; Bordallo, C; Rendueles, P; Gascón, S; Carton, J A; Maradona, J A; Arribas, J M

1997-01-01

203

Effect of lactic, acetic and citric acids on quality changes of refrigerated green mussel, Perna viridis (Linnaeus, 1758  

Directory of Open Access Journals (Sweden)

Full Text Available Effect of lactic, acetic and citric acids on the quality changes and shelf-life extension of green mussel stored at 4oC was investigated. The inhibitory effect on bacterial growth was pronounced when the concentration of lactic, acetic and citric acids increased (P<0.05. Green mussel dipped with lactic acid had the lower total volatile base, trimethylamine, ammonia and TCA-soluble peptides contents than those dipped in acetic and citric acids. However, the increases in exudates loss and cooking loss were observed in samples dipped in organic acids, causing the denaturation of muscle protein by acids used. Thiobarbituric acid reactive substances (TBARS increased as the organic acid concentration increased (P<0.05. Lactic acid dipped samples, particularly with 0.2 M, showed the greater acceptability than did those dipped in other acids throughout the storage of 27 days. The control sample had the acceptability only for 6 days of storage.

Payap Masniyom

2007-07-01

204

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

205

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

OpenAIRE

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

206

Calculations with weak protolytes: titration of acetic acid with NaOH solution.  

OpenAIRE

In this exercise, the pH value of four points in the titration of a weak acid (acetic acid) is calculated. The first point corresponds to the initial solution of the acid (no titrant was added); the second one corresponds to a substoichiometric situation (the equivalence point was not reached). The third point is the equivalence point and the last one defines a overtitration condition. Calculations are carried out in a puzzle-like expression and the results must be entered to be checked. The ...

Milla Gonza?lez, Miguel

2013-01-01

207

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.)

208

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

Energy Technology Data Exchange (ETDEWEB)

Positron-emitting (1-/sup 11/C)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-/sup 14/C)acetate was administered as a bolus to Langendorf-perfused rat hearts and effluent /sup 14/CO/sub 2/ and labeled metabolites measured. /sup 14/CO/sub 2/ cleared monoexponentially between 5 and 25 min post administration, representing 90-97% of total effluent /sup 14/C activity. In control hearts, perfused with glucose 5 mM and insulin, 10 mU/ml t1/2 for /sup 14/CO/sub 2/ clearance was 3.4 +/- 0.2 min (n=5). TCA cycle flux, estimated from substrate utilization rates correlated linearly with 1/t1/2 when MVO/sub 2/ 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-/sup 11/C) acetate clearance from myocardium detected by PET may allow in vivo estimation of TCA cycle flux. (1-/sup 14/C) palmitate administration under control conditions demonstrated similar initial /sup 14/CO/sub 2/ 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 < 0.02); TCA cycle flux and acetate kinetics were unaltered. Thus, combined use of (1-/sup 11/C) acetate and palmitate may allow dissection of the site of inhibition of fatty acid oxidation in vivo in normal and pathophysiological conditions.

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

1987-05-01

209

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

210

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

211

Analysis of Indole-3-Acetic Acid and Related Indoles in Culture Medium from Azospirillum lipoferum and Azospirillum brasilense  

OpenAIRE

Analysis of neutral and acidic ethyl acetate extracts from culture medium of Azospirillum brasilense 703Ebc by high-performance liquid chromatography (HPLC) and combined gas chromatography-mass spectrometry demonstrated the presence of indole-3-acetic acid (IAA), indole-3-ethanol, indole-3-methanol, and indole-3-lactic acid. IAA in media of 20 strains of A. brasilense and Azospirillum lipoferum was analyzed quantitatively by both the colorimetric Salkowski assay and HPLC-based isotopic diluti...

Crozier, Alan; Arruda, Paulo; Jasmim, Janie M.; Monteiro, Ana Maria; Sandberg, Go?ran

1988-01-01

212

Main and interaction effects of acetic acid, furfural, and p-hydroxybenzoic acid on growth and ethanol productivity of yeasts  

Energy Technology Data Exchange (ETDEWEB)

The influence of the factors acetic acid, furfural, and p-hydroxybenzoic acid on the ethanol yield (Y{sub EtOH}) of Saccharomyces cerevisiae, bakers` yeast, S. cerevisiae ATCC 96581, and Candida shehatae NJ 23 was investigated using a 2{sup 3}-full factorial design with 3 centerpoints. The results indicated that acetic acid inhibited the fermentation by C. shehatae NJ 23 markedly more than by bakers` yeast, whereas no significant difference in tolerance towards the compounds was detected between the S. cerevisiae strains. Furfural and the lignin derived compound p-hydroxybenzoic acid did not affect any of the yeasts at the cell mass concentration used. The results indicated that the linear model was not adequate to describe the experimental data. Based on the results from the 2{sup 3}-full factorial experiment, an extended experiment was designed based on a central composite design to investigate the influence of the factors on the specific growth rate ({mu}), biomass yield (Y{sub x}), volumetric ethanol productivity (Q{sub EtOH}), and Y{sub EtOH}. Bakers` yeast was chosen in the extended experiment due to its better tolerance towards acetic acid, which makes it a more interesting organism for use in industrial fermentations of lignocellulosic hydrolysates.

Palmqvist, E.; Grage, H.; Meinander, N.Q.; Hahn-Haegerdal, B. [Univ. of Lund (Sweden)

1999-04-05

213

Theoretical study of the hydration of atmospheric nucleation precursors with acetic acid.  

Science.gov (United States)

While atmosphere is known to contain a significant fraction of organic substance and the effect of acetic acid to stabilize hydrated sulfuric acids is found to be close that of ammonia, the details about the hydration of (CH3COOH)(H2SO4)2 are poorly understood, especially for the larger clusters with more water molecules. We have investigated structural characteristics and thermodynamics of the hydrates using density functional theory (DFT) at PW91PW91/6-311++G(3df,3pd) level. The phenomena of the structural evolution may exist during the early stage of the clusters formation, and we tentatively proposed a calculation path for the Gibbs free energies of the clusters formation via the structural evolution. The results in this study supply a picture of the first deprotonation of sulfuric acids for a system consisting of two sulfuric acid molecules, an acetic acid molecule, and up to three waters at 0 and 298.15 K, respectively. We also replace one of the sulfuric acids with a bisulfate anion in (CH3COOH)(H2SO4)2 to explore the difference of acid dissociation between two series of clusters and interaction of performance in clusters growth between ion-mediated nucleation and organics-enhanced nucleation. PMID:25143013

Zhu, Yu-Peng; Liu, Yi-Rong; Huang, Teng; Jiang, Shuai; Xu, Kang-Ming; Wen, Hui; Zhang, Wei-Jun; Huang, Wei

2014-09-11

214

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

215

Synthesis of 2, 4-- dichloro phenoxy acetic acid [ Carboxy- 14 C] as herbicide  

International Nuclear Information System (INIS)

One of the important herbicide, that can be used for the practical mechanism investigations and studies of metabolism functions of different plants is 2,4 dichlorophenoxy acetic acid compound. In this article, the production method for labeling the titled compound is explained. At the first stage of this research work, barium[14C] carbonate is converted into potassium [14C] by using potassium azid at a reasonable temperature. Then, after a few synthesis reaction, the compound 2,4 dichlorophenoxy methyl iodide is produced via 2,4 dichlorophenoxy as a starting material. At the next stage, the real material as a herbicide: 2,4 dichlorophenoxy acetic acid [carboxy- 14C] is prepared and produced, by the coupling reaction between 2,4 dichlorophenoxy methyl iodide and potassium [14C] cyanide, and then the resulting nitrile has been hydrolyzed

216

Conclusion on the peer review of the pesticide risk assessment of the active substance acetic acid  

Directory of Open Access Journals (Sweden)

Full Text Available The conclusions of the European Food Safety Authority (EFSA following the peer review of the initial risk assessments carried out by the competent authority of the rapporteur Member State, Germany, for the pesticide active substance acetic acid are reported. The context of the peer review was that required by Commission Regulation (EC No 2229/2004, as amended by Commission Regulation (EC No 1095/2007 and Commission Regulation (EU No. 114/2010. The conclusions were reached on the basis of the evaluation of the representative uses of acetic acid as a herbicide in pome fruit, stone fruit, paths and roads, ornamental trees and shrubs, turf, and lawns. The reliable endpoints concluded as being appropriate for use in regulatory risk assessment, derived from the available studies and literature in the dossier peer reviewed, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are identified.

European Food Safety Authority

2013-01-01

217

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

218

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

219

Indole-3-acetic acid (IAA) production by Arthrobacter species isolated from Azolla.  

Science.gov (United States)

Arthrobacter species, isolated from the leaf cavities and the microsporocarps of the aquatic fern species Azolla pinnata and Azolla filiculoides, produced indole-3-acetic acid (IAA) in culture when the precursor tryptophan was added to the medium. No IAA production was detected in the absence of tryptophan. Maximum IAA formation was obtained in the first 2 d of incubation. Part of the tryptophan was transformed to N alpha-acetyl-L-tryptophan. PMID:1564446

Forni, C; Riov, J; Grilli Caiola, M; Tel-Or, E

1992-02-01

220

Production of the Phytohormone Indole-3-Acetic Acid by Estuarine Species of the Genus Vibrio?  

OpenAIRE

Strains of Vibrio spp. isolated from roots of the estuarine grasses Spartina alterniflora and Juncus roemerianus produce the phytohormone indole-3-acetic acid (IAA). The colorimetric Salkowski assay was used for initial screening of IAA production. Gas chromatography-mass spectroscopy (GC-MS) was then employed to confirm and quantify IAA production. The accuracy of IAA quantification by the Salkowski assay was examined by comparison to GC-MS assay values. Indole-3-acetamide, an intermediate i...

Gutierrez, Casandra K.; Matsui, George Y.; Lincoln, David E.; Lovell, Charles R.

2009-01-01

221

Ultrastructure of Sheep Primordial Follicles Cultured in the Presence of Indol Acetic Acid, EGF, and FSH  

OpenAIRE

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 suppleme...

José Ricardo Figueiredo; Marcelo Marcondes Seneda; José Roberto Viana Silva; Amauri Alcindo Alfieri; Poul Maddox-Hyttel; Fernanda Da Cruz Landim-Alvarenga; Ricardo Toniolli; Evelyn Rabelo Andrade

2010-01-01

222

Acetic acid modulates spike rate and spike latency to salt in peripheral gustatory neurons of rats  

OpenAIRE

Sour and salt taste interactions are not well understood in the peripheral gustatory system. Therefore, we investigated the interaction of acetic acid and NaCl on taste processing by rat chorda tympani neurons. We recorded multi-unit responses from the severed chorda tympani nerve (CT) and single-cell responses from intact narrowly tuned and broadly tuned salt-sensitive neurons in the geniculate ganglion simultaneously with stimulus-evoked summated potentials to signal when the stimulus conta...

Breza, Joseph M.; Contreras, Robert J.

2012-01-01

223

Evaluation of an acetic acid ester of monoglyceride as a suppository base with unique properties  

OpenAIRE

The objective of this investigation was to evaluate an acetic acid ester of monoglycerides made from edible, fully hydrogenated palm oil (AC-70) as a suppository based and compare it with a commercially available semisynthetic base (Suppocire AI®). Benzocaine and miconazole were used as model drugs. Suppositories were prepared by the fusion method. The drug loads in the suppositories were kept at 2% to 5% (wt/wt). In vitro release of drug from the suppositories into Sorensen's phosphate buff...

Dash, Alekha K.; Cudworth, Greggrey C.

2001-01-01

224

Biosynthesis of Indole-3-Acetic Acid by the Pine Ectomycorrhizal Fungus Pisolithus tinctorius  

OpenAIRE

Previous work has indicated that anatomical and morphological changes (stunting and dichotomy) in roots of various conifers may be influenced by plant-growth-regulating substances secreted by mycorrhizae. Indole-3-acetic acid (IAA) has been tentatively identified as a major auxin produced by some selected ectomycorrhizae. We report the isolation and detection of IAA as a secondary metabolite from Pisolithus tinctorius by thin-layer chromatography, high-performance liquid chromatography (HPLC)...

Frankenberger, W. T.; Poth, M.

1987-01-01

225

N-(7-Methyl-1,8-naphthyridin-2-ylacetamide–acetic acid (1/1  

Directory of Open Access Journals (Sweden)

Full Text Available In the title adduct, C11H11N3O·C2H4O2, all non-H atoms of the acetamide molecule are roughly coplanar, with an r.m.s. deviation of 0.0720?Å. The dihedral angle between the ring plane and the acetamide group is 8.5?(2°. In the crystal, O—H...N and N—H...O hydrogen bonds link the acetamide and acetic acid molecules.

Gao-Zhang Gou

2013-04-01

226

Rotational Isomerism in Acetic Acid: The First Experimental Observation of the High-Energy Conformer  

OpenAIRE

The high-energy conformer of acetic acid (cis-AA) is produced in an Ar matrix by vibrational excitation of the OH stretching overtone of the ground conformational state (trans-AA). IR-absorption spectroscopy provides a clear identification of the reaction product. cis-AA converts back to trans-AA in a time scale of minutes at 8 K by tunneling.

Mac?o?as, Ermelinda M. S.; Khriachtchev, Leonid; Pettersson, Mika; Fausto, Rui; Ra?sa?nen, Markku

2003-01-01

227

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

OpenAIRE

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...

Ahmad Yaganeh Moghadam; Mohammad Ali Asadi; Rohullah Dehghani; Ali Zarei Mahmoudabadi; Fariba Rayegan; Hossein Hooshyar2; Ahmad Khorshidi

2010-01-01

228

The Enhancement of Catharanthine Content in Catharanthus roseus Callus Culture Treated with Naphtalene Acetic Acid  

OpenAIRE

The research aim was to examine the enhancement of catharanthine content in Catharanthus roseus callus culture added with different concentration of Naphtalene Acetic Acid (NAA). NAA treatment produced callus that formed hairy roots. Fresh and dry weight of callus increased as the increasing of NAA concentration. The catharanthine content of C. roseus callus culture was increased by adding NAA as well. The highest catharanthine content was found in 2.5 ppm NAA added callus.

DINGSE PANDIANGAN; NELSON NAINGGOLAN

2006-01-01

229

The Enhancement of Catharanthine Content in Catharanthus roseus Callus Culture Treated with Naphtalene Acetic Acid  

Directory of Open Access Journals (Sweden)

Full Text Available The research aim was to examine the enhancement of catharanthine content in Catharanthus roseus callus culture added with different concentration of Naphtalene Acetic Acid (NAA. NAA treatment produced callus that formed hairy roots. Fresh and dry weight of callus increased as the increasing of NAA concentration. The catharanthine content of C. roseus callus culture was increased by adding NAA as well. The highest catharanthine content was found in 2.5 ppm NAA added callus.

DINGSE PANDIANGAN

2006-09-01

230

Application of molecular techniques for identification and ennumeration of acetic acid bacteria  

OpenAIRE

Application of molecular techniques for identification and enumeration of acetic acid bacteria:Los principales objetivos de la tesis son el desarrollo de técnicas de biología molecular rápidas y fiables para caracterizar bacterias acéticas.Las bacterias acéticas son las principales responsables del picado de los vinos y de la producción de vinagre. Sin embargo, existe un desconocimiento importante sobre su comportamiento y evolución. Las técnicas de enumeración y de identificación b...

Gonza?lez Benito, Angel

2005-01-01

231

Removal of benzylidene acetal and benzyl ether in carbohydrate derivatives using triethylsilane and Pd/C  

Directory of Open Access Journals (Sweden)

Full Text Available Clean deprotection of carbohydrate derivatives containing benzylidene acetals and benzyl ethers was achieved under catalytic transfer hydrogenation conditions by using a combination of triethylsilane and 10% Pd/C in CH3OH at room temperature. A variety of carbohydrate diol derivatives were prepared from their benzylidene derivatives in excellent yield.

Abhishek Santra

2013-01-01

232

Pb(II) and Zn(II) adsorption onto Na- and Ca-montmorillonites in acetic acid/acetate medium: experimental approach and geochemical modeling.  

Science.gov (United States)

Smectites are usually used as a clay barrier at the bottom of subsurface waste landfills due to their low permeability and their capacity to retain pollutants. The Na- and Ca-saturated SWy2 montmorillonites were interacted with initial Zn(NO(3))(2) or Pb(NO(3))(2) concentrations ranging from 10(-6) to 10(-2)M with a solid/liquid ratio of 10 g L(-1) and using acetic acid/acetate as buffer at pH 5 in order to reproduce a biodegradable leachate of a young landfill. These experiments revealed that Zn and Pb sorption onto Na-SWy2 is higher than that onto Ca-SWy2 in the whole range of concentrations. Metal retention into both montmorillonites increases with the decrease in acetic acid/acetate concentration. The two-site protolysis model with no electrostatic term (2SPNE model) was used to model these experiments. As the experimental data of Zn sorption were well fitted, this model was validated and has been improved by taking into account the metal-acetate complexation in solution. In order to validate the model for Pb sorption, new selectivity coefficients have been determined, namely logK(c)(PbNa)=0.5 for Na-montmorillonite and logK(c)(PbCa)=0.3 for Ca-montmorillonite. PMID:21641613

Ghayaza, Mariem; Le Forestier, Lydie; Muller, Fabrice; Tournassat, Christophe; Beny, Jean-Michel

2011-09-01

233

Pulse radiolysis of aqueous solutions of acetic acid 2-hydroxyethyl ester  

International Nuclear Information System (INIS)

The reaction of OH radicals with acetic acid 2-hydroxyethyl ester, in aqueous solutions has been studied. A rate constant of ksub(OH + 1) = 8.5 x 108 M-1 s-1 was obtained. The transients a few ?s after pulse consist of approximately 83% formylmethyl radicals, CH2CHO, the remainder being mainly CH3C(O)OCHCH2OH radicals. ?-radiolysis of 1 in N2O saturated aqueous solutions led to G(acetic acid) = 5.0 without contribution of a chain reaction. A lower limit of the rate constant of this reaction, at 200C, k >= 5 x 105 s-1, was derived from pulse radiolysis and an upper limit of k 6 s-1 was estimated from scavenging experiments with oxygen under Co60-?-irradiation. At higher concentrations of 1, and/or higher temperatures CH2CHO attacks 1, leading to a chain decomposition of 1 yielding acetic acid and acetaldehyde. Succinic aldehyde was identified as a product of the dimerization of CH2CHO. (orig./HK)

234

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)

235

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

236

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

237

Corrosion resistance of aluminum-magnesium alloys in glacial acetic acid  

International Nuclear Information System (INIS)

Vessels for the storage and conveyance of glacial acetic acid are produced from ADO and AD1 aluminum, which are distinguished by corrosion resistance, weldability and workability in the hot and cold conditions but have low tensile strength. Aluminum-magnesium alloys are stronger materials close in corrosion resistance to technical purity aluminum. An investigation was made of the basic alloying components on the corrosion resistance of these alloys in glacial acetic acid. Both the base metal and the weld joints were tested. With an increase in temperature the corrosion rate of all of the tested materials increases by tens of times. The metals with higher magnesium content show more pitting damage. The relationship of the corrosion resistance of the alloys to magnesium content is confirmed by the similar intensity of failure of the joint metal of all of the investigated alloys and by electrochemical investigations. The data shows that AMg3 alloy is close to technically pure ADO aluminum. However, the susceptibility of even this material to local corrosion eliminates the possibility of the use of aluminum-magnesium alloys as reliable constructional materials in glacial acetic acid

238

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

239

Unimolecular decomposition of formic and acetic acids: A shock tube/laser absorption study  

KAUST Repository

The thermal decomposition of formic acid (HCOOH) and acetic acid (CH3COOH), two carboxylic acids which play an important role in oxygenate combustion chemistry, were investigated behind reflected shock waves using laser absorption. The rate constants of the primary decomposition pathways of these acids:(HCOOH ? CO + H2 O (R 1); HCOOH ? CO2 + H2 (R 2); CH3 COOH ? CH4 + CO2 (R 3); CH3 COOH ? CH2 CO + H2 O (R 4)) were measured using simultaneous infrared laser absorption of CO, CO2 and H2O at wavelengths of 4.56, 4.18 and 2.93 microns, respectively. Reaction test conditions covered temperatures from 1230 to 1821 K and pressures from 1.0 to 6.5 atm for dilute mixtures of acids (0.25-0.6%) in argon. The rate constants of dehydration (R1) and decarboxylation (R2) reactions of formic acid were calculated by fitting exponential functions to the measured CO, CO2 and H2O time-history profiles. These two decomposition channels were found to be in the fall-off region and have a branching ratio, k1/k2, of approximately 20 over the range of pressures studied here. The best-fit Arrhenius expressions of the first-order rates of R1 and R2 were found to be:(k1 (1 atm) = 1.03 × 1011 exp (- 25651 / T) s- 1 (± 37 %); k1 (6.5 atm) = 9.12 × 1012 exp (- 30275 / T) s- 1 (± 32 %); k2 (1 atm) = 1.79 × 108 exp (- 21133 / T) s- 1 (± 41 %); k2 (6.5 atm) = 2.73 × 108 exp (- 20074 / T) s- 1 (± 37 %)). The rate constants for acetic acid decomposition were obtained by fitting simulated profiles, using an acetic acid pyrolysis mechanism, to the measured species time-histories. The branching ratio, k4/k3, was found to be approximately 2. The decarboxylation and dehydration reactions of acetic acid appear to be in the falloff region over the tested pressure range:(k3 (1 atm) = 3.18 × 1011 exp (- 28679 / T) s- 1 (± 30 %); k3 (6 atm) = 3.51 × 1012 exp (- 31330 / T) s- 1 (± 26 %); k4 (1 atm) = 7.9 × 1011 exp (- 29056 / T) s- 1 (± 34 %); k4 (6 atm) = 6.34 × 1012 exp (- 31330 / T) s- 1 (± 31 %) .). © 2014 The Combustion Institute.

Elwardany, A.

2014-07-16

240

Rapid and Effective Removal of Perfluorooctanoic Acid from Proteomics Samples  

OpenAIRE

We recently demonstrated that perfluorooctanoic acid (PFOA), a volatile surfactant, is as effective as sodium dodecyl sulfate (SDS) at solubilizing membrane proteins. PFOA can be removed by repeated evaporation prior to mass spectrometry analysis. However, removal of PFOA by evaporation is a lengthy process that takes approximately 6 hrs. Toward the goal of decreasing the length of time required to remove PFOA from protein digests, we tested the efficiency of PFOA removal and subsequent pepti...

Kadiyala, Chandra Sekhar Rao; Mullangi, Vennela; Zhou, Xiang; Vukoti, Krishna M.; Miyagi, Masaru

2012-01-01

241

Adaptive response to acetic acid in the highly resistant yeast species Zygosaccharomyces bailii revealed by quantitative proteomics.  

Science.gov (United States)

Zygosaccharomyces bailii is the most tolerant yeast species to acetic acid-induced toxicity, being able to grow in the presence of concentrations of this food preservative close to the legal limits. For this reason, Z. bailii is the most important microbial contaminant of acidic food products but the mechanisms behind this intrinsic resistance to acetic acid are very poorly characterized. To gain insights into the adaptive response and tolerance to acetic acid in Z. bailii, we explored an expression proteomics approach, based on quantitative 2DE, to identify alterations occurring in the protein content in response to sudden exposure or balanced growth in the presence of an inhibitory but nonlethal concentration of this weak acid. A coordinate increase in the content of proteins involved in cellular metabolism, in particular, in carbohydrate metabolism (Mdh1p, Aco1p, Cit1p, Idh2p, and Lpd1p) and energy generation (Atp1p and Atp2p), as well as in general and oxidative stress response (Sod2p, Dak2p, Omp2p) was registered. Results reinforce the concept that glucose and acetic acid are coconsumed in Z. bailii, with acetate being channeled into the tricarboxylic acid cycle. When acetic acid is the sole carbon source, results suggest the activation of gluconeogenic and pentose phosphate pathways, based on the increased content of several proteins of these pathways after glucose exhaustion. PMID:22685079

Guerreiro, Joana F; Mira, Nuno P; Sá-Correia, Isabel

2012-08-01

242

Effective trapping of fruit flies with cultures of metabolically modified acetic Acid bacteria.  

Science.gov (United States)

Acetoin in vinegar is an attractant to fruit flies when combined with acetic acid. To make vinegar more effective in attracting fruit flies with increased acetoin production, Komagataeibacter europaeus KGMA0119 was modified by specific gene disruption of the acetohydroxyacid isomeroreductase gene (ilvC). A previously constructed mutant lacking the putative ligand-sensing region in the leucine-responsive regulatory protein (KeLrp, encoded by Kelrp) was also used. The ilvC and Kelrp disruptants (KGMA5511 and KGMA7203, respectively) produced greater amounts of acetoin (KGMA5511, 0.11%; KGMA7203, 0.13%) than the wild-type strain KGMA0119 (0.069%). KGMA7203 produced a trace amount of isobutyric acid (0.007%), but the other strains did not. These strains produced approximately equal amounts of acetic acid (0.7%). The efficiency of fruit fly attraction was investigated with cultured Drosophila melanogaster. D. melanogaster flies (approximately 1,500) were released inside a cage (2.5 m by 2.5 m by 1.5 m) and were trapped with a device containing vinegar and a sticky sheet. The flies trapped on the sticky sheet were counted. The cell-free supernatant from KGMA7203 culture captured significantly more flies (19.36 to 36.96% of released flies) than did KGMA0119 (3.25 to 11.40%) and KGMA5511 (6.87 to 21.50%) cultures. Contrastingly, a 0.7% acetic acid solution containing acetoin (0.13%) and isobutyric acid (0.007%), which mimicked the KGMA7203 supernatant, captured significantly fewer flies (0.88 to 4.57%). Furthermore, the KGMA0119 supernatant with additional acetoin (0.13%) and isobutyric acid (0.007%) captured slightly more flies than the original KGMA0119 supernatant but fewer than the KGMA7203 supernatant, suggesting that the synergistic effects of acetic acid, acetoin, isobutyric acid, and unidentified metabolites achieved the efficient fly trapping of the KGMA7203 supernatant. PMID:25595769

Ishii, Yuri; Akasaka, Naoki; Goda, Itsuko; Sakoda, Hisao; Fujiwara, Shinsuke

2015-04-01

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]. Thus, combined use of [1-11C] acetate and palmitate may allow dissection of the site of inhibition of fatty acid oxidation in vivo in normal and pathophysiological conditions

244

Acidity measurements on a heteropolyacid hydrate in acetic acid solution: A case of three hydrons ionizing independently, rather than consecutively  

Energy Technology Data Exchange (ETDEWEB)

Acidity measurements by {sup 13}C NMR spectroscopy with mesityl oxide (2) as indicator (the {Delta} {delta} method) have been conducted on phosphotungstic acid, H{sub 3}PW{sub 12}O{sub 40} (1) at various levels of hydration, H{sub 3}PW{sub 12}O{sub 40} {center_dot} xH{sub 2}O (1b) in concentrated solution in acetic acid. Extrapolation to infinite dilution of indicator allowed the determination of the H{sub 0} acidity function. A comparison with the strong acids, sulfuric and perchloric, indicate that even in this solvent of low basicity the three hydrons of 1 dissociate independently, rather than consecutively as considered previously. The molecule of the heteropolyacid is thus equivalent to three molecules of strong acid in solution and behaves in essence like the solid acids, having acid sites of the same strength. Comparison with other acids has to be made at triple concentrations of the latter and shows that the complex acid 1 is significantly stronger than perchloric acid, which in turn is stronger than sulfuric acid, as already known. 20 refs., 1 fig., 3 tabs.

Farcasiu, D.; Li, Jing Qi [Univ. of Pittsburgh, PA (United States)

1995-03-01

245

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

246

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

247

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

248

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

249

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

OpenAIRE

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 arra...

Rajib Roychowdhury; Anuj Mamgain; Sunanda Ray; Jagatpati Tah

2012-01-01

250

Clinical study of CT-guided sclerotherapy using 50 percent acetic acid in the treatment of renal cyst  

International Nuclear Information System (INIS)

Objective: To investigate the efficacy of 50% acetic acid as a renal cyst sclerotherapy agent, and with further comparison to that of absolute alcohol. Methods: Eighty five patients with renal cyst were undergone sclerotherapy through spiral CT guidance including 43 cases with absolute alcohol and the others with 50% acetic acid as selerosing agents. All the cysts were aspirated under CT-guidance, beforehand. The selerosising agents were withdrawn from the cysts after a definite period of retention. Results: The disappearance rates of cyst cavity with absolute alcohol and acetic acid were 55.81% and 71.42%, respectively. Complication occurenee rates with absolute alcohol and acetic acid were 16.28% and 4.76%, respectively. The average retention periods of absolute alcohol and acetic acid in cyst were (20±4) minutes, and (10±2)minutes, respectively. Statistical analysis demonstrated that all the data in two groups were significantly different. Conclusion: Using 50% acetic acid as sclerosising agent in treating renal cyst possesses the better effect and less side effect, providing a tendency to replace the traditional therapy. (authors)

251

Radiolabeled acetate as a tracer of myocardial tricarboxylic acid cycle flux  

International Nuclear Information System (INIS)

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 clts 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

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

A mutation affecting the synthesis of 4-chloroindole-3-acetic acid.  

Science.gov (United States)

Traditionally, schemes depicting auxin biosynthesis in plants have been notoriously complex. They have involved up to four possible pathways by which the amino acid tryptophan might be converted to the main active auxin, indole-3-acetic acid (IAA), while another pathway was suggested to bypass tryptophan altogether. It was also postulated that different plants use different pathways, further adding to the complexity. In 2011, however, it was suggested that one of the four tryptophan-dependent pathways, via indole-3-pyruvic acid (IPyA), is the main pathway in Arabidopsis thaliana, although concurrent operation of one or more other pathways has not been excluded. We recently showed that, for seeds of Pisum sativum (pea), it is possible to go one step further. Our new evidence indicates that the IPyA pathway is the only tryptophan-dependent IAA synthesis pathway operating in pea seeds. We also demonstrated that the main auxin in developing pea seeds, 4-chloroindole-3-acetic acid (4-Cl-IAA), which accumulates to levels far exceeding those of IAA, is synthesized via a chlorinated version of the IPyA pathway. PMID:23073010

Ross, John J; Tivendale, Nathan D; Davidson, Sandra E; Reid, James B; Davies, Noel W; Quittenden, Laura J; Smith, Jason A

2012-12-01

254

Gluconacetobacter kakiaceti sp. nov., an acetic acid bacterium isolated from a traditional Japanese fruit vinegar.  

Science.gov (United States)

Two novel acetic acid bacteria, strains G5-1(T) and I5-1, were isolated from traditional kaki vinegar (produced from fruits of kaki, Diospyros kaki Thunb.), collected in Kumamoto Prefecture, Japan. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strains G5-1(T) and I5-1 formed a distinct subline in the genus Gluconacetobacter and were closely related to Gluconacetobacter swingsii DST GL01(T) (99.3% 16S rRNA gene sequence similarity). The isolates showed 96-100% DNA-DNA relatedness with each other, but isolates could be distinguished from closely related members of the genus Gluconacetobacter by not producing 2- and 5-ketogluconic acids from glucose, producing cellulose, growing without acetic acid and with 30% (w/v) d-glucose, and producing acid from sugars and alcohols. Furthermore, the genomic DNA G+C contents of strains G5-1(T) and I5-1 were a little higher than those of their closest phylogenetic neighbours. On the basis of the phenotypic characteristics and phylogenetic position, strains G5-1(T) and I5-1 are assigned to a novel species, for which the name Gluconacetobacter kakiaceti sp. nov. is proposed; the type strain is G5-1(T) (=JCM 25156(T)=NRIC 0798(T)=LMG 26206(T)). PMID:21841006

Iino, Takao; Suzuki, Rei; Tanaka, Naoto; Kosako, Yoshimasa; Ohkuma, Moriya; Komagata, Kazuo; Uchimura, Tai

2012-07-01

255

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

256

Removal of radium from sand filters by inorganic acids  

International Nuclear Information System (INIS)

Sand filters are used in water treatment stations to remove particulate matter from underground water, where iron and manganese are collected forming thin oxide films. These oxides of iron and manganese adsorb radium from underground water. Radium concentration increases in time on the filters, and consequently the level of radioactivity increases in the station. The removal of adsorbed radium on sand using inorganic acids was studied. Good efficiency of radium removal was obtained by controlling different parameters like temperature, time, pH, addition of competitive cations and anions. It was found that hydrochloric acid is the best for radium removal from sand filters. Maximum removal obtained was about 60% at 5M BaCl2 and 2M HCl at 50 deg C for 180-minute contact time. Kinetic parameters of the removal process were studied and compared with literature data. (author)

257

Purification and partial characterization of acetic acid esterase from malted finger millet (Eleusine coracana, Indaf-15).  

Science.gov (United States)

Acetic acid esterase (EC 3.1.1.6) cleaves the acetyl groups substituted at O-2/O-3 of the xylan backbone of arabinoxylans and is known to modulate their functional properties. To date, this enzyme from cereals has not received much attention. In the present study, acetic acid esterase from 72 h ragi malt was isolated and purified to apparent homogeneity by a four-step purification, i.e., ammonium sulfate precipitation, DEAE-cellulose, Sephacryl S-200, and phenyl-Sepharose column chromatography, with a recovery of 0.36% and a fold purification of 34. The products liberated from alpha-NA and PNPA by the action of purified ragi acetic acid esterase were authenticated by ESI-MS and 1H NMR. The pH and temperature optima of the enzyme were found to be 7.5 and 45 degrees C, respectively. The enzyme is stable in the pH range of 6.0-9.0 and temperature range of 30-40 degrees C. The activation energy of the enzymatic reaction was found to be 7.29 kJ mol-1. The apparent Km and Vmax of the purified acetic acid esterase for alpha-NA were 0.04 microM and 0.175 microM min-1 mL-1, respectively. The molecular weight of the native enzyme was found to be 79.4 kDa by GPC whereas the denatured enzyme was found to be 19.7 kDa on SDS, indicating it to be a tetramer. EDTA, citric acid, and metal ions such as Fe+3 and Cu+2 increased the activity while Ni+2, Ca+2, Co+2, Ba+2, Mg+2, Mn+2, Zn+2, and Al+3 reduced the activity. Group-specific reagents such as eserine and PCMB at 25 mM concentration completely inhibited the enzyme while iodoacetamide did not have any effect. Eserine was found to be a competitive inhibitor. PMID:17263491

Latha, G Madhavi; Muralikrishna, G

2007-02-01

258

Impact of gluconic fermentation of strawberry using acetic acid bacteria on amino acids and biogenic amines profile.  

Science.gov (United States)

This paper studies the amino acid profile of beverages obtained through the fermentation of strawberry purée by a surface culture using three strains belonging to different acetic acid bacteria species (one of Gluconobacter japonicus, one of Gluconobacter oxydans and one of Acetobacter malorum). An HPLC-UV method involving diethyl ethoxymethylenemalonate (DEEMM) was adapted and validated. From the entire set of 21 amino acids, multiple linear regressions showed that glutamine, alanine, arginine, tryptophan, GABA and proline were significantly related to the fermentation process. Furthermore, linear discriminant analysis classified 100% of the samples correctly in accordance with the microorganism involved. G. japonicus consumed glucose most quickly and achieved the greatest decrease in amino acid concentration. None of the 8 biogenic amines were detected in the final products, which could serve as a safety guarantee for these strawberry gluconic fermentation beverages, in this regard. PMID:25704705

Ordóñez, J L; Sainz, F; Callejón, R M; Troncoso, A M; Torija, M J; García-Parrilla, M C

2015-07-01

259

Restoration of reproductive potential after expiration or removal of melengestrol acetate contraceptive implants in Tigers (Panthera tigris).  

Science.gov (United States)

The need for contraception in the successful management of captive wild animals is becoming increasingly apparent. Because concerns exist regarding the reversibility of the contraceptive implant melengestrol acetate (MGA), reproductive data for 94 female Amur (Panthera tigris altaica) and Sumatran tigers (Panthera tigris sumatrae) were analyzed using survival analyses to evaluate return to reproductive status after implant removal or assumed expiration. Females placed in potential breeding situations after MGA implants were surgically removed showed a 62% return to reproduction by 5.25 years, whereas females with implants that were assumed to have expired showed only a 30% return to reproduction by 6 years. Implanted females did not reproduce as successfully as non-implanted control females, which showed an 85% probability of reproducing after placement in a new breeding situation by 2.66 years. Parturition increased the probability of reproducing in non-implanted females, but not in implanted females. Litter size, stillbirths, and offspring survival were not significantly different between non-implanted, implant-removed and implant-expired female tigers. Ten female tigers reproduced both before and after implant placement, and the differences in litter size, stillbirths, and offspring survival were not significant, nor were they significantly different from non-implanted females. Prior parturition, age when implant was removed, and duration of implantation did not affect the probability of reproducing for females after implant removal. These results show substantial reversibility of MGA implants, leading to 62% successful reproduction after implant removal. The reasons for lower successful reproduction in animals previously treated with the contraceptive compared to non-implanted females are not known, but a greater delay in reversibility was seen when implants were left in place and only presumed expired. Zoo Biol 26:275-288, 2007. (c) 2007 Wiley-Liss, Inc. PMID:19360580

Chuei, Jason Y; Asa, Cheryl S; Hall-Woods, Monica; Ballou, Jonathon; Traylor-Holzer, Kathy

2007-07-01

260

Isolation of novel indole-3-acetic acid conjugates by immunoaffinity extraction.  

Science.gov (United States)

An analytical protocol for the isolation and quantification of indole-3-acetic acid (IAA) and its amino acid conjugates was developed. IAA is an important phytohormone and formation of its conjugates plays a crucial role in regulating IAA levels in plants. The developed protocol combines a highly specific immunoaffinity extraction with a sensitive and selective LC-MS/MS analysis. By using internal standards for each of the studied compounds, IAA and seven amino acid conjugates were analyzed in quantities of fresh plant material as low as 30 mg. In seeds of Helleborus niger, physiological levels of these compounds were found to range from 7.5 nmol g(-1) fresh weight (IAA) to 0.44 pmol g(-1) fresh weight (conjugate with Ala). To our knowledge, the identification of IAA conjugates with Gly, Phe and Val from higher plants is reported here for the first time. PMID:19836533

Pencík, Ales; Rolcík, Jakub; Novák, Ondrej; Magnus, Volker; Barták, Petr; Buchtík, Roman; Salopek-Sondi, Branka; Strnad, Miroslav

2009-12-15

261

Removal of arsenic from sulphuric acid solutions  

International Nuclear Information System (INIS)

Extraction of As(III) and As(V) from sulphuric acids solutions of H2SO4 of various concentration (50-200 g/dm3 with Cyanex 923 dissolved in Exxsol 220/230) was studied and compared. Cyanex 923 can be considered as an effective arsenic extractant. Sulphuric acid is co-extracted. Extraction both of As(III) and As(V) occurs quickly and the equilibrium is obtained after 5 minutes. The isotherms of As(III) and As(V) extraction at various sulphuric acid concentrations were determined and used to model the multistage countercurrent process. Arsenic can be stripped with water. (author)

262

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

263

Graft Loss Due to Percutaneous Sclerotherapy of a Lymphocele Using Acetic Acid After Renal Transplantation  

International Nuclear Information System (INIS)

Development of lymphoceles after renal transplantation is a well-described complication that occurs in up to 40% of recipients. The gold standard approach for the treatment of symptomatic cases is not well defined yet. Management options include simple aspiration, marsupialization by a laparotomy or laparoscopy, and percutaneous sclerotherapy using different chemical agents. Those approaches can be associated, and they depend on type, dimension, and localization of the lymphocele. Percutaneous sclerotherapy is considered to be less invasive than the surgical approach; it can be used safely and effectively, with low morbidity, in huge, rapidly accumulating lymphoceles. Moreover, this approach is highly successful, and the complication rate is acceptable; the major drawback is a recurrence rate close to 20%. We herewith report a renal transplant case in which the patient developed a symptomatic lymphocele that was initially treated by ultrasound-guided percutaneous sclerotherapy with ethanol and thereafter using acetic acid for early recurrence. A few hours after injection of acetic acid in the lymphatic cavity, the patient started to complain of acute pain localized to the renal graft and fever. An ultrasound of the abdomen revealed thrombosis of the renal vein and artery. The patient was immediately taken to the operating room, where the diagnosis of vascular thrombosis was confirmed and the graft was urgently explanted. In conclusion, we strongly suggest avoiding thenclusion, we strongly suggest avoiding the use of acetic acid as a slerosating agent for the percutaneous treatment of post-renal transplant lymphocele because, based on our experience, it could be complicated by vascular thrombosis of the kidney, ending in graft loss

264

A peculiar stimulatory effect of acetic and lactic acid on growth and fermentative metabolism of Zygosaccharomyces bailii.  

Science.gov (United States)

Stimulatory or protective effects of organic acids at low concentrations, e.g. acetic and lactic acid, on microorganisms have previously been reported. Especially in case of Zygosaccharomyces bailii, a peculiar growth stimulation by these two acids has recently been noticed. In order to elucidate this interesting phenomenon, growth and fermentative metabolism of Z. bailii was investigated in media with low pH (pH 4.0), high sugar (15% (w/v)) and different acetic and lactic acid concentrations. At both experimental temperatures (7 and 30 degrees C), a growth stimulation in the presence of 2.5% (v/v) lactic acid was observed. Furthermore at 7 degrees C, the yeast exhibited another unusual behaviour as it grew much faster in media containing 1.25% (v/v) acetic acid than in the control (without any acid). Production of fermentative metabolites was also increased together with the enhanced growth at both temperatures. These possible stimulatory effects of acetic and lactic acid should be taken into consideration when the acids are used at low doses for food preservative purpose. Presence of the acids may stimulate Z. bailii growth and fermentative metabolism, particularly at refrigeration temperature, consequently resulting in an earlier spoilage. PMID:19269576

Dang, T D T; Vermeulen, A; Ragaert, P; Devlieghere, F

2009-05-01

265

The synthesis of acetic acid from methane via oxidative bromination, carbonylation, and hydrolysis  

Energy Technology Data Exchange (ETDEWEB)

Acetyl bromide and acetic acid (AA) were synthesized from methane by an energy-saving process. By reacting methane with oxygen in the presence of HBr and H{sub 2}O over a 2.5% Ba 2.5% La 0.5% Ni 0.1% Ru/SiO{sub 2} catalyst, methane was converted to CH{sub 3}Br and CO (CH{sub 3}Br/CO molar ratio=1/1) with a CH{sub 4} single-pass conversion of 70% at 660{sup o}C. Our results showed that CH{sub 3}Br was formed via the interaction of methane with bromine radicals whereas CO was generated in the oxidation of CH{sub 3}Br. Through the carbonylation of CH{sub 3}Br over RhCl{sub 3}-KI or RhCl{sub 3}-PPh{sub 3} (triphenyl phosphine) catalyst in propanoic acid, acetyl bromide could be synthesized and readily hydrolysed to acetic acid at room temperature (with more than 99.7% yield based on CH{sub 3}Br). The promotional action of PPh{sub 3} and KI is realized via the direct coordination of PPh{sub 3} to Rh and the conversion of CH{sub 3}Br to CH{sub 3}I by means of Br-I exchange, respectively. (author)

Wang, K.X.; Xu, H.F.; Li, W.S.; Au, C.T.; Zhou, X.P. [Department of Chemical Engineering, Hunan University, Hunan 410082 (China)

2006-05-10

266

Biosynthesis of Indole-3-Acetic Acid by the Pine Ectomycorrhizal Fungus Pisolithus tinctorius.  

Science.gov (United States)

Previous work has indicated that anatomical and morphological changes (stunting and dichotomy) in roots of various conifers may be influenced by plant-growth-regulating substances secreted by mycorrhizae. Indole-3-acetic acid (IAA) has been tentatively identified as a major auxin produced by some selected ectomycorrhizae. We report the isolation and detection of IAA as a secondary metabolite from Pisolithus tinctorius by thin-layer chromatography, high-performance liquid chromatography (HPLC), enzyme-linked immunosorbent (monoclonal antibody) assay (ELISA), and unequivocal identification by gas chromatography-mass spectrometry (GC-MS). The thin-layer chromatography methods for auxin isolation described here are novel, with the use of heptane-acetone-glacial acetic acid as the migrating solvent and formaldehyde, H(2)SO(4), and vanadate in detection. The acidic extract of the culture supernatant was methylated with ethereal diazomethane to detect IAA as methyl-3-IAA by HPLC, ELISA, and GC-MS. The quantitative amount of IAA detected ranged from 4 to 5 mumol liter by HPLC and ELISA. Another unidentified metabolite was detected by GC-MS with a typical indole nucleus (m/z = 130), indicating that it could be an intermediate in auxin metabolism. Plant response (Pseudotsuga menziesii, Douglas fir) was monitored upon inoculation of P. tinctorius and l-tryptophan. There was a consistent increase in plant height and stem diameter as a result of the two treatments, with statistical differences in dry weights of the shoots and roots. PMID:16347506

Frankenberger, W T; Poth, M

1987-12-01

267

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

268

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

Scientific Electronic Library Online (English)

Full Text Available 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.

2011-02-01

269

Electrogeneration of iodine (1) from methyl iodide in acetic acid for application in coulometric analysis  

International Nuclear Information System (INIS)

Conditions of electrochemical preparation of I(1) from methyl iodide in acetic acid are found. The I(1) current efficiency is close to 100% at current densities from 1.1 up to 3.3 mA/cm2. The actual redox potential of the I(1)/CH3I system in HAc is 1.186+-0.001 V. The scheme of two-electron electrochemical CH3I oxidation is proposed. The electrogenerated I(1) is used for electrochemical iodination of some organic compounds for the coulometric analysis

270

Effect of various substituted acetic acid compounds on the extraction of Eu(III) by HDEHP  

International Nuclear Information System (INIS)

The present paper reports the results obtained on the effect of various substituted acetic acid compounds (EDTA, CDTA, EDPA and DTPA) on the extraction of Eu(III) by HDEHP. The effect of temperature on the distribution of Eu(III) in these systems also studied. The results showed an increase of extraction with temperature rise, for most additives concentrations studied, indicating that extraction is an endothermic process. The results were compared and discussed for the above mentioned 4 complexing agents. 7 figs., 1 tab

271

Global Effect of Indole-3-Acetic Acid Biosynthesis on Multiple Virulence Factors of Erwinia chrysanthemi 3937?  

OpenAIRE

Production of the plant hormone indole-3-acetic acid (IAA) is widespread among plant-associated microorganisms. The non-gall-forming phytopathogen Erwinia chrysanthemi 3937 (strain Ech3937) possesses iaaM (ASAP16562) and iaaH (ASAP16563) gene homologues. In this work, the null knockout iaaM mutant strain Ech138 was constructed. The IAA production by Ech138 was reduced in M9 minimal medium supplemented with l-tryptophan. Compared with wild-type Ech3937, Ech138 exhibited reduced ability to prod...

Yang, Shihui; Zhang, Qiu; Guo, Jianhua; Charkowski, Amy O.; Glick, Bernard R.; Ibekwe, A. Mark; Cooksey, Donald A.; Yang, Ching-hong

2006-01-01

272

(Liquid + liquid) equilibria for (water + acetic acid + 2-ethyl-1-hexanol): experimental data and prediction  

International Nuclear Information System (INIS)

(Liquid + liquid) equilibrium (LLE) data for (water + acetic acid + 2-ethyl-1-hexanol) were measured at atmospheric pressure in the temperature range of (298.2 to 313.2) K. The UNIFAC model was used to predict the observed LLE data with a root-mean-square deviation value of 2.03%. A high degree of consistency of experimental data was obtained using the Othmer-Tobias correlation. The solubility of water in 2-ethyl-1-hexanol was measured at different temperatures

273

Measurement of glomerular filtration rate in children using technetium-99m diethylenetriamine penta-acetic acid  

International Nuclear Information System (INIS)

During the past 5 years, we have measured the glomerular filtration rate (GFR) by the slope-clearance method using technetium-99m diethylenetriamine penta-acetic acid technetium-99m-DTPA in 130 infants and children. The results in 22 children have been compared with inulin clearance, and a very good correlation between the two methods of measurement of GFR was demonstrated (r = 0,9616; P less than 0,0001). This study provides further evidence that technetium-99m-DTPA is a satisfactory agent for the clinical measurement of GFR in children

274

Nitrilase in biosynthesis of the plant hormone indole-3-acetic acid from indole-3-acetonitrile: cloning of the Alcaligenes gene and site-directed mutagenesis of cysteine residues.  

OpenAIRE

Indole-3-acetic acid is the major auxin in most plants. In Cruciferae, including Brassicaceae, indole-3-acetic acid is synthesized from indole-3-acetonitrile by nitrilase, after indole-3-acetonitrile is formed from tryptophan via indole-3-acetaldoxime or indole glycosinolates as the intermediate. We cloned and sequenced the gene for nitrilase (EC 3.5.5.1), which catalyzes the hydrolysis of indole-3-acetonitrile to indole-3-acetic acid, from Alcaligenes faecalis JM3. The amino acid sequence de...

Kobayashi, M.; Izui, H.; Nagasawa, T.; Yamada, H.

1993-01-01

275

Ionic liquid assisted electrospun cellulose acetate fibers for aqueous removal of triclosan.  

Science.gov (United States)

The cellulose acetate (CA) membrane prepared via electrospun was innovatively utilized as fiber-adsorbent for the separation of aqueous triclson (TCS). It was found that the presence of the room temperature ionic liquid (RTIL) in the precursor amplified electric force toward the CA-solution, thereby benefiting the formation of CA fibers. The as-spun CA fibers exhibit excellent adsorptive performance toward TCS, with fast adsorption kinetics, and the maximum adsorption capacity achieved to 797.7 mg g(-1), which established much better performance in contrast to conventional adsorbents. We proposed that the adsorption of TCS onto CA fibers was primarily facilitated by the hydrogen bonding between the abundant carbonyl, hydroxyl groups of CA surface, and the hydrogen atoms of phenol functional groups in TCS molecular. PMID:25595432

Zhang, Gong; Sun, Meng; Liu, Yang; Liu, Huijuan; Qu, Jiuhui; Li, Jinghong

2015-02-10

276

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.

277

Techno-economic Analysis for the Thermochemical Conversion of Lignocellulosic Biomass to Ethanol via Acetic Acid Synthesis  

Energy Technology Data Exchange (ETDEWEB)

Biomass is a renewable energy resource that can be converted into liquid fuel suitable for transportation applications. As a widely available biomass form, lignocellulosic biomass can have a major impact on domestic transportation fuel supplies and thus help meet the Energy Independence and Security Act renewable energy goals (U.S. Congress 2007). This study performs a techno-economic analysis of the thermo chemical conversion of biomass to ethanol, through methanol and acetic acid, followed by hydrogenation of acetic acid to ethanol. The conversion of syngas to methanol and methanol to acetic acid are well-proven technologies with high conversions and yields. This study was undertaken to determine if this highly selective route to ethanol could provide an already established economically attractive route to ethanol. The feedstock was assumed to be wood chips at 2000 metric ton/day (dry basis). Two types of gasification technologies were evaluated: an indirectly-heated gasifier and a directly-heated oxygen-blown gasifier. Process models were developed and a cost analysis was performed. The carbon monoxide used for acetic acid synthesis from methanol and the hydrogen used for hydrogenation were assumed to be purchased and not derived from the gasifier. Analysis results show that ethanol selling prices are estimated to be $2.79/gallon and $2.81/gallon for the indirectly-heated gasifier and the directly-heated gasifier systems, respectively (1stQ 2008$, 10% ROI). These costs are above the ethanol market price for during the same time period ($1.50 - $2.50/gal). The co-production of acetic acid greatly improves the process economics as shown in the figure below. Here, 20% of the acetic acid is diverted from ethanol production and assumed to be sold as a co-product at the prevailing market prices ($0.40 - $0.60/lb acetic acid), resulting in competitive ethanol production costs.

Zhu, Yunhua; Jones, Susanne B.

2009-04-01

278

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.

Falås, Per; Baillon-Dhumez, Aude

2012-01-01

279

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 (<70%) between SKU 1109 and the type strains of the closest phylogenetic neighbors. The classification of strains LMG 1529(T) and SKU 1109 into a single novel species was confirmed also by AFLP and (GTG)(5)-PCR DNA fingerprinting data, as well as by phenotypic data. Strains LMG 1529(T) and SKU 1109 can be differentiated from their closely related 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

280

Deuterium isotope effects and solvolysis of tosylates of cis- and trans-2-phenylcyclopentanol in formic acid, acetic acid and ethanol  

International Nuclear Information System (INIS)

The solvolysis of the tosylates of cis and trans 2-phenylcyclopentanol has been studied in formic acid, acetic acid and ethanol by kinetic measurements and secondary isotopes effects. In the case of the cis isomer, hydrogen migration (93 to 97%) from C-2 occurs after rapid ionisation of the tosylate to form an ion-pair which subsequently gives a bridged intermediate in a slow step. With the trans isomer the migration of the hydrogen atom (15 to 47%) and that of the phenyl group (38% in formic acid solution; less than 10% in the two other solvents) would occur in a slow step after ionisation of the tosylate to an intimate ion-pair which dissociates to a loose solvent-separated ion-pair

281

Rhodanineacetic Acid Derivatives as Potential Drugs: Preparation, Hydrophobic Properties and Antifungal Activity of (5-Arylalkylidene-4-oxo-2-thioxo-1,3-thiazolidin-3-yl)acetic Acids  

OpenAIRE

Some [(5Z)-(5-arylalkylidene-4-oxo-2-thioxo-1,3-thiazolidin-3-yl)]acetic acids were prepared as potential antifungal compounds. The general synthetic approach to all synthesized compounds is presented. Lipophilicity of all the discussed rhodanine-3-acetic acid derivatives was analyzed using a reversed phase high performance liquid chromatography (RP-HPLC) method. The procedure was performed under isocratic conditions with methanol as an organic modifier in the mobile phase using an end-capped...

Josef Jampilek; Jiri Kunes; Vejsova Marcela; Petra Hirsova; Jiri Dohnal; Veronika Opletalova; Jan Dolezel

2009-01-01

282

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

283

Genomic Expression Program Involving the Haa1p-Regulon in Saccharomyces cerevisiae Response to Acetic Acid  

OpenAIRE

The alterations occurring in yeast genomic expression during early response to acetic acid and the involvement of the transcription factor Haa1p in this transcriptional reprogramming are described in this study. Haa1p was found to regulate, directly or indirectly, the transcription of approximately 80% of the acetic acid-activated genes, suggesting that Haa1p is the main player in the control of yeast response to this weak acid. The genes identified in this work as being activated in response...

Mira, Nuno P.; Becker, Jorg D.; Sa?-correia, Isabel

2010-01-01

284

Enantioselective Synthesis of 1,2-Dihydronaphthalene-1-carbaldehydes by Addition of Boronates to Isochromene Acetals Catalyzed by Tartaric Acid.  

Science.gov (United States)

Tartaric acid is an ideal asymmetric catalyst as it is abundant, cheap, and environmentally friendly. (+)-Tartaric acid was found to catalyze a novel enantioselective [4 + 2] cycloaddition of isochromene acetals and vinylboronates. A variety of substituted isochromene acetals were tolerated, furnishing the desired dihydronaphthalenes and dihydrobenzofluorene products in good yields. High enantiomeric ratios (up to 98.5:1.5) and excellent diastereoselectivities (all >99:1) were observed employing 10 mol % of (+)-tartaric acid as the catalyst, in combination with 5 mol % of Ho(OTf)3. PMID:25715172

Luan, Yi; Barbato, Keith S; Moquist, Philip N; Kodama, Tomohiro; Schaus, Scott E

2015-03-11

285

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...

286

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)

287

Sulphydryl groups and iodo-[3H]acetic acid labeling in proteolipids from Torpedo electroplax  

International Nuclear Information System (INIS)

Several fractions of proteolipids from Torpedo electroplax were separated by DEAE-cellulose chromatography in organic solvents, and the sulphydryl groups were determined by a spectrophotometric method. On the same fractions the covalent labeling with iodo-[3H]acetic acid to sulphydryl groups was studied. In total proteolipids there were 30.3 nmol/mg protein of sulphydryl groups of which 20.6 nmoles were in the form of disulfide bonds and 10.9 nmol as free--SH groups. The highest content of sulphydryl groups (36.7 nmol/mg protein) was found in fraction II; while fraction I, that binds the cholinergic ligands, has a lower content (23.7 nmol/mg protein). The 42 Kdaltons polypeptide, which is the major band in Fraction II, has the strongest labeling with iodo-[3H]acetic acid, while the 39 Kdaltons cholinergic polypeptide shows a lower labeling. The importance of proteolipids as channel-forming macromolecules is discussed in connection with the possible significance of the 42 Kdaltons polypeptide

288

Deposition of vinyl acetic acid through the pulsed RF plasma polymerization  

International Nuclear Information System (INIS)

In this paper, pulsed RF plasma polymerization using vinyl acetic acid was investigated to obtain plasma polymers with less cross-linked structure and high-degree retention of the starting monomer groups. The chemical structure and the surface morphology of the polymerized vinyl acetic acid were characterized by Fourier transform infrared (FTIR) spectroscopy, x-ray photoelectron spectroscope (XPS) and scanning electron microscope (SEM). The duty cycles were observed to be one of the key parameters to change the film structure. The FTIR results showed that more carboxylic groups could be 'retained' with the decrease of the duty cycles. The XPS results were consistent with the FTIR measurements. Surface energy measurements indicated that the plasma films were hydrophilic. So controlling the chemical composition with some special surface functional groups being 'retained' or 'tailored' was available by pulsed plasma technologies. Some regular graft 'lighting' network patterns were interestingly found in the plasma films kept at room temperature for some time by SEM. It was estimated that the plasma polymerization proceeded differently along the 'lighting' network and on the valley of the pattern. The details need to be further studied

289

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

290

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

291

The effect of acetic acid on the CO2 corrosion of grade X70 steel  

International Nuclear Information System (INIS)

The effect of acetic acid (HAc) on the CO2 corrosion of grade X70 steel was investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), polarization tests and electrochemical impedance spectroscopy (EIS). In the absence of acetic acid, a fairly dense layer of iron carbonate (FeCO3/siderite) was formed. At 500 ppm HAc, FeCO3 layer became more porous. In addition, anodic/cathodic polarization curves were activated with the more pronounced effect on the cathodic side. By adding 1000 ppm HAc, similar polarization behavior was obtained and FeCO3 layer became yet more porous than previous conditions. At 2000 ppm HAc, FeCO3 layer disappeared completely, while polarization behavior changed and the limiting diffusive current density was observed in the cathodic side. There were two major increases in the corrosion rate at 500 and 2000 ppm HAc. The EIS results reflected similar behavior for the specimens exposed to the solutions with 0-1000 ppm HAc. Under these conditions, a charge transfer controlled behavior due to the FeCO3 layer was observed which was accelerated by increasing HAc concentration. At 2000 ppm HAc, the corrosion behavior changed considerably and the formation/adsorption of corrosion product followed by the dissolution process was observed.

292

Acetal-linked branched poly(dimethyl-aminoethyl methacrylate) as an acid cleavable gene vector with reduced cytotoxicity.  

Science.gov (United States)

An acid labile branched PDMAEMA/acetal copolymer with amino group was synthesized by the DE-ATRP and followed by Michael addition. The degradation of the polymer was strongly pH-dependent. High nucleic acid transfection efficiency with low cytotoxicity was observed compared to its non-degradable copolymer counterpart. PMID:25358033

Cao, H L; Dong, Y X; Aied, A; Zhao, T Y; Chen, X; Wang, W X; Pandit, A

2014-12-21

293

The Effect of Pre-chilling with Acetic and Lactic Acid on Shelf-life of Broiler Carcasses  

Directory of Open Access Journals (Sweden)

Full Text Available The effect of pre-chilling in acetic and lactic acid solutions on shelf-life of broiler carcass was investigated. Broiler carcasses were subjected to a 10-min pre-chill treatment with acetic acid, lactic acid and combination of them and examined for their sensorial properties, microbiological quality, pH values and ammonia levels. Treating with organic acids decreased initial microbial load of the carcasses, but not changed their colour, odour and appearance. Controls were spoiled on the 4th day of the storage. The shelf-life of carcasses treated with organic acids were 2-4 days longer. Especially, treatments with 0.6 % lactic acid and 1.0 % acetic acid enhanced the shelf-life twice more. Microbial counts (especially pseudomonas, NH3 amount and pH values of carcass were increased parallel to sensorial alterations. The data from the present study suggest that the treatment of broiler carcasses with pre-chill water containing acetic or lactic acid can help to decontaminate and to increase the shelf-life of carcasses without altering the colour and appearance of the skin.

Kamil Bostan

2001-01-01

294

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

295

Photodissociation of organic molecules in star-forming regions II: Acetic acid  

CERN Document Server

Fragments from organic molecule dissociation (such as reactive ions and radicals) can form interstellar complex molecules like amino acids. The goal of this work is to experimentally study photoionization and photodissociation processes of acetic acid (CH$_3$COOH), a glycine (NH$_2$CH$_2$COOH) precursor molecule, by soft X-ray photons. The measurements were taken at the Brazilian Synchrotron Light Laboratory (LNLS), employing soft X-ray photons from a toroidal grating monochromator (TGM) beamline (100 - 310 eV). Mass spectra were obtained using the photoelectron photoion coincidence (PEPICO) method. Kinetic energy distribution and abundances for each ionic fragment have been obtained from the analysis of the corresponding peak shapes in the mass spectra. Absolute photoionization and photodissociation cross sections were also determined. We have found, among the channels leading to ionization, that only 4-6% of CH$_3$COOH survive the strong ionization field. CH$_3$CO$^+$, COOH$^+$ and CH$_3^+$ ions are the mai...

Pilling, S; Boechat-Roberty, H M

2006-01-01

296

Biorefining of wheat straw using an acetic and formic acid based organosolv fractionation process.  

Science.gov (United States)

To assess the potential of acetic and formic acid organosolv fractionation of wheat straw as basis of an integral biorefinery concept, detailed knowledge on yield, composition and purity of the obtained streams is needed. Therefore, the process was performed, all fractions extensively characterized and the mass balance studied. Cellulose pulp yield was 48% of straw dry matter, while it was 21% and 27% for the lignin and hemicellulose-rich fractions. Composition analysis showed that 67% of wheat straw xylan and 96% of lignin were solubilized during the process, resulting in cellulose pulp of 63% purity, containing 93% of wheat straw cellulose. The isolated lignin fraction contained 84% of initial lignin and had a purity of 78%. A good part of wheat straw xylan (58%) ended up in the hemicellulose-rich fraction, half of it as monomeric xylose, together with proteins (44%), minerals (69%) and noticeable amounts of acids used during processing. PMID:24508905

Snelders, Jeroen; Dornez, Emmie; Benjelloun-Mlayah, Bouchra; Huijgen, Wouter J J; de Wild, Paul J; Gosselink, Richard J A; Gerritsma, Jort; Courtin, Christophe M

2014-03-01

297

Synthesis and extractive properties of dialkyl aminomethyl-substituted dialkyl amides of diphenylphosphinoyl acetic acid  

International Nuclear Information System (INIS)

Dialkyl amides of diphenylphosphinoyl acetic acids, dialkyl aminomethyl-substituted by the methylene group, were prepared by means of the Mannich reaction from diphenyl(dialkyl carbamoylmethyl)-phosphine oxides or by reaction of the latter compounds with tetraethyl methylenediamine. Extractive ability of the prepared compounds toward U(VI) and Pd(II) in nitrate media was studied as a function of the organic solvent nature, concentrations of extractant, ammonium nitrate and nitric acid. In dichloroethane the stoichiometric U:L ratio in extractable complexes is found to be 1:2 for all extractants studied. The highest value of uranium distribution factor (D=5.54) is obtained when nitrobenzene is used as an organic solvent

298

Synthesis of new imidazolyl acetic acid derivatives with anti-inflammatory and analgesic activities.  

Science.gov (United States)

We synthesized 2-(4-(4-fluorobenzylidene)-2-(4-fluorophenyl) 5-oxo-4,5-dihydroimidazol-1-yl) acetic acid 3. Chlorination afforded the chloro derivative 4, which reacted with different amines and hydrazine to afford compounds 5-8. Pyrazole, pyrazolone, and thiazolidinone derivatives were also synthesized from Imidazol-1-ylacetic acid hydrazide 8 to give compounds 9-12. Compounds were then evaluated for their anti-inflammatory activity against carrageenan-induced rat paw edema and their analgesic activity using the writhing test in albino mice. Compounds 5, 9, 10, 12 exhibited maximum anti-inflammatory activity, and all the compounds inhibited writhing, with 10 and 12 being two times more effective than the reference standard. PMID:18449497

Khalifa, Maha M; Abdelbaky, Nayira A

2008-04-01

299

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english 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 a [...] ntibacterial 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; Munawar Ali, Munawar; Muhammad, Ashraf; Saeed Ahmad, Nagra; , Mehr-Un-Nisa; Ismat, Fatima.

1237-12-01

300

Regulation of acetic acid production by homo- and heterofermentative lactobacilli in whole-wheat sour-doughs.  

Science.gov (United States)

The efficiency of sour-dough as a possible preservative agent of microbial spoilage of bread depends on its acetic acid content. As a secondary metabolite of sugar fermentation by lactic acid bacteria, acetic acid may be promoted in the presence of O2 or H+ acceptors. This paper studies the influence of O2 and high fructose content products (pure sugar, invert sugar, fructose syrup) addition on acetic acid production by hetero- (Lactobacillus brevis 25a, B-21, L-62; L. sanfrancisco L-99) and homofermentative (L. plantarum B-39) lactobacilli in whole-wheat sour-doughs [280 and 250 dough yield (DY)]. The pH and total titratable acidity (TTA) of sour-doughs after 44 h fermentation varied with DY and strain. As expected, the addition of O2 promoted greater increases in TTA with heterofermentative lactobacilli (15-42%) than with L. plantarum (15%). Fructose addition was only effective for heterofermentative strains, but the overall effects were smaller than those observed for oxygenation. The ability of lactobacilli to produce acetic acid in sour-doughs without treatment varied from 0.16 g/100 g flour at 44 h (B-39, 280, 350 DY) to 0.47-0.65% (L-62, 280, 350 DY). The production of acetic acid was positively promoted by all treatments. Oxygenation was again the most effective way of inducing acetic acid production; increases ranged from 54% (B-21) to 269% (L-99, 350 DY). The addition of H+ acceptors had variable effects.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7975904

Martínez-Anaya, M A; Llin, M L; Pilar Macías, M; Collar, C

1994-09-01

301

Studies on the complexes of uranium(IV), thorium(IV) and lanthanum(III) acetates with p-aminobenzoic acid, m-aminobenzoic acid, benzilic acid and phthalic acid  

International Nuclear Information System (INIS)

Complexes of acetates of U(IV), Th(IV) and La(III) with the ligands p-aminobenzoic acid, m-aminobenzoic acid, benzilic acid and phthalic acid have been prepared. Colour and chemical analytical data are recorded. They are characterised on the basis of IR and reflectance spectra and magnetic susceptibility data. (M.G.B.)

302

Gluconacetobacter medellinensis sp. nov., cellulose- and non-cellulose-producing acetic acid bacteria isolated from vinegar.  

Science.gov (United States)

The phylogenetic position of a cellulose-producing acetic acid bacterium, strain ID13488, isolated from commercially available Colombian homemade fruit vinegar, was investigated. Analyses using nearly complete 16S rRNA gene sequences, nearly complete 16S-23S rRNA gene internal transcribed spacer (ITS) sequences, as well as concatenated partial sequences of the housekeeping genes dnaK, groEL and rpoB, allocated the micro-organism to the genus Gluconacetobacter, and more precisely to the Gluconacetobacter xylinus group. Moreover, the data suggested that the micro-organism belongs to a novel species in this genus, together with LMG 1693(T), a non-cellulose-producing strain isolated from vinegar by Kondo and previously classified as a strain of Gluconacetobacter xylinus. DNA-DNA hybridizations confirmed this finding, revealing a DNA-DNA relatedness value of 81?% between strains ID13488 and LMG 1693(T), and values produce 2- and 5-keto-d-gluconic acid from d-glucose, their ability to produce acid from sucrose, but not from 1-propanol, and their ability to grow on 3?% ethanol in the absence of acetic acid and on ethanol, d-ribose, d-xylose, sucrose, sorbitol, d-mannitol and d-gluconate as carbon sources. The DNA G+C content of strains ID13488 and LMG 1693(T) was 58.0 and 60.7 mol%, respectively. The major ubiquinone of LMG 1693(T) was Q-10. Taken together these data indicate that strains ID13488 and LMG 1693(T) represent a novel species of the genus Gluconacetobacter for which the name Gluconacetobacter medellinensis sp. nov. is proposed. The type strain is LMG 1693(T) (?=?NBRC 3288(T)?=?Kondo 51(T)). PMID:22729025

Castro, Cristina; Cleenwerck, Ilse; Trcek, Janja; Zuluaga, Robin; De Vos, Paul; Caro, Gloria; Aguirre, Ricardo; Putaux, Jean-Luc; Gañán, Piedad

2013-03-01

303

Production of acetic acid and glycerol from salted and dried whey in a membrane cell recycle bioreactor  

Energy Technology Data Exchange (ETDEWEB)

The use of salted whey (liquid by-product from the dairy industry containing 7.5% NaCl) as a substrate for either acetic acid or glycerol production was investigated using two yeast strains. One was Kluyveromyces fragilis. The other organism (strain L) can utilize whey lactose that was isolated from waste whey (disposal stream). 8% NaCl, 3% Na{sub 2}SO{sub 3} and pH 8.5 at 32{sup o}C were the optimum operating conditions for maximum acetic acid production (25.84 gl{sup -1}) from salted whey using immobilized cells of yeast strain L. Also, strain L have a higher yield of acetic acid (0.497 g acetic acid per gram lactose) as compared with K. fragilis (0.322 g acetic acid per gram lactose). 1% Na{sub 2}SO{sub 3} at pH 7 and whey supplemented with peptone and malt extract were the optimal conditions for maximum batch glycerol production (13.2 gl{sup -1}) from salted whey using immobilized cells of K. fragilis. The extreme values, 18.7 gl{sup -1} for glycerol concentration and 39.78 for the percent yield of glycerol (based on sugar concentration) in a membrane cell recycle bioreactor were higher than those obtained for the immobilized cell batch reactors (13.2 gl{sup -1} and 28, respectively). (Author)

Mostafa, N.A. [Minia Univ. (Egypt). Dept. of Chemical Engineering

2001-07-01

304

Formation of N,N-Dimethylglycine, Acetic Acid, and Butyric Acid from Betaine by Eubacterium limosum  

OpenAIRE

Two bacterial strains that grow anaerobically on betaine were isolated from enrichment cultures and identified as strains of Eubacterium limosum. In a mineral medium supplemented with yeast extract and Casitone, the doubling time of E. limosum strain 11A on betaine was 6 h at 37°C. The molar growth yield amounted to 9 g of dry cell mass per mol. Betaine was fermented in accordance with the following equation: 7 betaine + 2 CO2 ? 7 N,N-dimethylglycine + 1.5 acetate + 1.5 butyrate. E. limosu...

Mu?ller, E.; Fahlbusch, K.; Walther, R.; Gottschalk, G.

1981-01-01

305

Crystal structure of an indole-3-acetic acid amido synthetase from grapevine involved in auxin homeostasis.  

Science.gov (United States)

Auxins are important for plant growth and development, including the control of fruit ripening. Conjugation to amino acids by indole-3-acetic acid (IAA)-amido synthetases is an important part of auxin homeostasis. The structure of the auxin-conjugating Gretchen Hagen3-1 (GH3-1) enzyme from grapevine (Vitis vinifera), in complex with an inhibitor (adenosine-5'-[2-(1H-indol-3-yl)ethyl]phosphate), is presented. Comparison with a previously published benzoate-conjugating enzyme from Arabidopsis thaliana indicates that grapevine GH3-1 has a highly similar domain structure and also undergoes a large conformational change during catalysis. Mutational analyses and structural comparisons with other proteins have identified residues likely to be involved in acyl group, amino acid, and ATP substrate binding. Vv GH3-1 is a monomer in solution and requires magnesium ions solely for the adenlyation reaction. Modeling of IAA and two synthetic auxins, benzothiazole-2-oxyacetic acid (BTOA) and 1-naphthaleneacetic acid (NAA), into the active site indicates that NAA and BTOA are likely to be poor substrates for this enzyme, confirming previous enzyme kinetic studies. This suggests a reason for the increased effectiveness of NAA and BTOA as auxins in planta and provides a tool for designing new and effective auxins. PMID:23136372

Peat, Thomas S; Böttcher, Christine; Newman, Janet; Lucent, Del; Cowieson, Nathan; Davies, Christopher

2012-11-01

306

Effect of humic acid on the underpotential deposition-stripping voltammetry of copper in acetic acid soil extract solutions at mercaptoacetic acid-modified gold electrodes  

International Nuclear Information System (INIS)

Electrochemical measurements were undertaken for the investigation of the underpotential deposition-stripping process of copper at bare and modified gold electrodes in 0.11 M acetic acid, the first fraction of the European Union's Bureau Communautaire de References (BCR) sequential extraction procedure for fractionating metals within soils and sediments. Gold electrodes modified with mercaptoacetic acid showed higher sensitivity for the detection of copper than bare gold electrodes, both in the absence and in the presence of humic acid in acetic acid solutions, using the underpotential deposition-stripping voltammetry (UPD-SV) method. In the presence of 50 mg l-1 of humic acid, the mercaptoacetic acid modified electrode proved to be 1.5 times more sensitive than the bare gold electrode. The mercaptoacetic acid monolayer formed on the gold surface provided efficient protection against the adsorption of humic acid onto the gold electrode surface. Variation of the humic acid concentration in the solution showed little effect on the copper stripping signal at the modified electrode. UPD-SV at the modified electrode was applied to the analysis of soil extract samples. Linear correlation of the electrochemical results with atomic spectroscopic results yielded the straight-line equation y (?g l-1) = 1.10x - 44 (ppb) (R=0.992, n=6), indicating good agreement between the two methods

307

Sol-gel process for preparing YBa2Cu4O8 precursors from Y, Ba, and Cu acidic acetates/ammonia/ascorbic acid systems  

International Nuclear Information System (INIS)

Sols were prepared by addition of ammonia to acidic acetate solutions of Y3+, Ba2+, and Cu2+. Ascorbic acid was added to a part of the sol. The resultant sols were gelled to a shard, a film, or microspheres by evaporation at 60 C or by extraction of water from drops of emulsion suspended in 2-ethylhexanol-1. Addition of ethanol to the sols facilitated the formation of gel films, fabricated by a dipping technique, on glass or silver substrates. At 100 C, gels that were formed in the presence of ascorbic acid were perfectly amorphous, in contrast to the crystalline acetate gels. Conversion of the amorphous ascorbate gels to final products was easier than for the acetate gels. The quality of coatings prepared from ascorbate gels was superior to that of acetate gel coatings

308

Biomonitoring of 2-(2-alkoxyethoxy)ethanols by analysing urinary 2-(2-alkoxyethoxy)acetic acids.  

Science.gov (United States)

2-Methoxyacetic and 2-ethoxyacetic acids are well known toxic metabolites of 2-alkoxyethanols. The use of 2-alkoxyethanols is now restricted, and the regulations have forced manufacturers to find substitutive solvents, 2-(2-alkoxyethoxy)ethanols. 2-(2-Alkoxyethoxy)ethanols resemble 2-alkoxyethanols, and their most hazardous similarity is their ability to metabolize to the 2-(2-alkoxyethoxy)acetic acids. In the present study, floor lacquerers' (n = 22) inhalation and total exposure to 2-(2-alkoxy)ethoxyethanols was measured. The measurements of inhalation exposure were done with charcoal tubes, and total exposure was biomonitored by urinalysis of 2-(2-alkoxyethoxy)acetic acids. The 8h inhalation exposures of floor lacquerers to 2-(2-methoxyethoxy)ethanol (DEGME), 2-(2-ethoxyethoxy)ethanol (DEGEE) and 2-(2-butoxyethoxy)ethanol (DEGBE) were in average 0.23 +/- 0.07 ppm (average+/-S.D., n = 3), 0.08 +/- 0.07 ppm (n = 16), and 0.05 +/- 0.03 ppm (n = 16), respectively. The excretions of 2-(2-methoxyethoxy)acetic acid (MEAA), 2-(2-ethoxyethoxy)acetic acid (EEAA) and 2-(2-butoxyethoxy)acetic acid (BEAA) were in average 4.9 +/- 4.3 mmol/mol creatinine, 9.3 +/- 8.0 mmol/mol creatinine and 9.2 +/- 7.4 mmol/mol creatinine, respectively. A linear relationship was found between the urinary 2-(2-alkoxyethoxy)acetic acid concentrations and the preceding 8-h occupational exposure to 2-(2-alkoxyethoxy)ethanol. PMID:15705492

Laitinen, J; Pulkkinen, J

2005-03-28

309

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

310

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

311

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

312

Effect of acetic acid on ZnO:In transparent conductive oxide prepared by ultrasonic spray pyrolysis  

International Nuclear Information System (INIS)

Undoped and indium doped zinc oxide (ZnO) transparent conductive oxide were prepared by a low-cost Ultrasonic Spray Pyrolysis. The influence of acetic acid on properties of the ZnO thin films was investigated. The complex formed by [CH3COO?] and [Zn2+] in precursor solution was better for the growth of ZnO film. The acetic acid added in precursor solution can supply [CH3COO?] for both [Zn2+] and [In3+] to form complexes. That made the [Zn2+] and [In3+] have similar statement, which can promote the indium doping in the ZnO films. The surface morphology, structural and electrical properties of the ZnO thin films were influenced by the acetic acid adding. The total transmittance of the ZnO thin films is above 80% in the wide wavelength region from 400 nm to 2000 nm.

313

Engineering efficient xylose metabolism into an acetic acid-tolerant Zymomonas mobilis strain by introducing adaptation-induced mutations.  

Science.gov (United States)

The impact of the two adaptation-induced mutations in an improved xylose-fermenting Zymomonas mobilis strain was investigated. The chromosomal mutation at the xylose reductase gene was critical to xylose metabolism by reducing xylitol formation. Together with the plasmid-borne mutation impacting xylose isomerase activity, these two mutations accounted for 80 % of the improvement achieved by adaptation. To generate a strain fermenting xylose in the presence of high acetic acid concentrations, we transferred the two mutations to an acetic acid-tolerant strain. The resulting strain fermented glucose + xylose (each at 5 % w/v) with 1 % (w/v) acetic acid at pH 5.8 to completion with an ethanol yield of 93.4 %, outperforming other reported strains. This work demonstrated the power of applying molecular understanding in strain improvement. PMID:22669340

Agrawal, Manoj; Wang, Yun; Chen, Rachel Ruizhen

2012-10-01

314

A contribution to the distinction of biogenic vinegar and vinegar made from synthetic acetic acid by determining the specific 14C-radioactivity  

International Nuclear Information System (INIS)

The method of Simon et al. for the separation of the acetic acid from vinegar prior to the determination of the specific 14C-radioactivity has been modified. The precipitation as calcium acetate and the preparation of free acetic acid by addition of diphosphoric acid has been replaced by an extraction procedure with diisopropylether which is faster and cheaper. On the Austrian market glacial acetic acid (Merck, p.A.) having the natural specific 14C-radioactivity was found. The natural specific 14C-radioactivity is therefore necessary but not sufficient to prove the biogenic origin of vinegar. (orig.)

315

Translocation of radiolabeled indole-3-acetic acid and indole-3-acetyl-myo-inositol from kernel to shoot of Zea mays L  

International Nuclear Information System (INIS)

Either 5-[3H]indole-3-acetic acid (IAA) or 5-[3H]indole-3-acetyl-myoinositol was applied to the endosperm of kernels of dark-grown Zea mays seedlings. The distribution of total radioactivity, radiolabeled indole-3-acetic acid, and radiolabeled ester conjugated indole-3-acetic acid, in the shoots was then determined. Differences were found in the distribution and chemical form of the radiolabeled indole-3-acetic acid in the shoot depending upon whether 5-[3H]indole-3-acetic acid or 5-[3H]indole-3-acetyl-myo-inositol was applied to the endosperm. We demonstrated that indole-3-acetyle-myo-inositol applied to the endosperm provides both free and ester conjugated indole-3-acetic acid to the mesocotyl and coleoptile. Free indole-3-acetic acid applied to the endosperm supplies some of the indole-3-acetic acid in the mesocotyl but essentially no indole-3-acetic acid to the coleoptile or primary leaves. It is concluded that free IAA from the endosperm is not a source of IAA for the coleoptile. Neither radioactive indole-3-acetyl-myo-inositol nor IAA accumulates in the tip of the coleoptile or the mesocotyl node and thus these studies do not explain how the coleoptile tip controls the amount of IAA in the shoot

316

Translocation of radiolabeled indole-3-acetic acid and indole-3-acetyl-myo-inositol from kernel to shoot of Zea mays L  

Science.gov (United States)

Either 5-[3H]indole-3-acetic acid (IAA) or 5-[3H]indole-3-acetyl-myo-inositol was applied to the endosperm of kernels of dark-grown Zea mays seedlings. The distribution of total radioactivity, radiolabeled indole-3-acetic acid, and radiolabeled ester conjugated indole-3-acetic acid, in the shoots was then determined. Differences were found in the distribution and chemical form of the radiolabeled indole-3-acetic acid in the shoot depending upon whether 5-[3H]indole-3-acetic acid or 5-[3H]indole-3-acetyl-myo-inositol was applied to the endosperm. We demonstrated that indole-3-acetyl-myo-inositol applied to the endosperm provides both free and ester conjugated indole-3-acetic acid to the mesocotyl and coleoptile. Free indole-3-acetic acid applied to the endosperm supplies some of the indole-3-acetic acid in the mesocotyl but essentially no indole-3-acetic acid to the coleoptile or primary leaves. It is concluded that free IAA from the endosperm is not a source of IAA for the coleoptile. Neither radioactive indole-3-acetyl-myo-inositol nor IAA accumulates in the tip of the coleoptile or the mesocotyl node and thus these studies do not explain how the coleoptile tip controls the amount of IAA in the shoot.

Chisnell, J. R.; Bandurski, R. S.

1988-01-01

317

Association and liquid structure of pyridine-acetic acid mixtures determined from neutron scattering using a 'free proton' EPSR simulation model.  

Science.gov (United States)

The liquid structure of pyridine-acetic acid mixtures have been investigated using neutron scattering at various mole fractions of acetic acid, ?HOAc = 0.33, 0.50, and 0.67 and compared to the structures of neat pyridine and acetic acid. Data has been modelled using empirical potential structure refinement (EPSR) with a 'free proton' reference model, which has no prejudicial weighting towards either the existence of molecular or ionised species. Analysis of the neutron scattering results shows the existence of hydrogen-bonded acetic acid chains with pyridine inclusions, rather than the formation of an ionic liquid by proton transfer. PMID:25670622

McCune, Jade A; Turner, Adam H; Coleman, Fergal; White, Caithlin M; Callear, Samantha K; Youngs, Tristan G A; Swad?ba-Kwa?ny, Ma?gorzata; Holbrey, John D

2015-03-14

318

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

319

Bombella intestini gen. nov., sp. nov., an acetic acid bacterium isolated from bumble bee crop.  

Science.gov (United States)

In the frame of a bumble bee gut microbiota study, acetic acid bacteria (AAB) were isolated using a combination of direct isolation methods and enrichment procedures. MALDI-TOF MS profiling of the isolates and a comparison of these profiles with profiles of established AAB species identified most isolates as Asaia astilbis or as 'Commensalibacter intestini', except for two isolates (R-52486 and LMG 28161(T)) that showed an identical profile. A nearly complete 16S rRNA gene sequence of strain LMG 28161(T) was determined and showed the highest pairwise similarity to Saccharibacter floricola S-877(T) (96.5%), which corresponded with genus level divergence in the family Acetobacteraceae. Isolate LMG 28161(T) was subjected to whole-genome shotgun sequencing; a 16S-23S rRNA internal transcribed spacer (ITS) sequence as well as partial sequences of the housekeeping genes dnaK, groEL and rpoB were extracted for phylogenetic analyses. The obtained data confirmed that this isolate is best classified into a new genus in the family Acetobacteraceae. The DNA G+C content of strain LMG 28161(T) was 54.9 mol%. The fatty acid compositions of isolates R-52486 and LMG 28161(T) were similar to those of established AAB species [with C18:1?7c (43.1%) as the major component], but the amounts of fatty acids such as C19:0 cyclo ?8c, C14:0 and C14:0 2-OH enabled to differentiate them. The major ubiquinone was Q-10. Both isolates could also be differentiated from the known genera of AAB by means of biochemical characteristics, such as their inability to oxidize ethanol to acetic acid, negligible acid production from melibiose, and notable acid production from d-fructose, sucrose and d-mannitol. In addition, they produced 2-keto-d-gluconate, but not 5-keto-d-gluconate from d-glucose. Therefore, the name Bombella intestini gen nov., sp. nov. is proposed for this new taxon, with LMG 28161(T) (?=DSM 28636(T)?=R-52487(T)) as the type strain of the type species. PMID:25336723

Li, Leilei; Praet, Jessy; Borremans, Wim; Nunes, Olga C; Manaia, Célia M; Cleenwerck, Ilse; Meeus, Ivan; Smagghe, Guy; De Vuyst, Luc; Vandamme, Peter

2015-01-01

320

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 toxicity 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.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 gástrica 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.

Cristina Setim Freitas

2008-08-01

321

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.

2008-08-01

322

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

323

Grafting onto polyester fibers. II. Kinetics of grafting of acrylic acid, acrylonitrile, and vinyl acetate onto polyester fibers  

International Nuclear Information System (INIS)

The kinetics of grafting of acrylonitrile, acrylic acid, and vinyl acetate onto polyester fiber by catalytic initiation and radiation were studied. The energy of activation determined for acrylic acid grafting by the catalytic method was 10.7 kcal/mole and that for vinyl acetate grafting by the radiation method, 11.7 kcal/mole. In the case of acrylonitrile grafting by the catalytic method, the rate of grafting decreased with increase in temperature of grafting, showing the differential behavior of the precipitating type of polymer from that of homogeneous polymerization. 5 figures

324

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)

325

Study on the IAA (Indole acetic acid) Productivity of Soil Yeast Strain Isolats  

International Nuclear Information System (INIS)

Twelve isolated soil yeast were tested in IAA production in peptone yeast glucose broth (PYG). All strains were screened for the Indole Acetic Acid (IAA) producing activity in PYG broth supplemented with or without L-Tryptophan (L-TRP) as precusor. IAA production was assayed calorimetrically using Salkowski's reagent. The concentration of IAA produced by yeast strains was measured by spectrophotometric method at 530nm. Y6 strain was the highest IAA producer (79ppm) at 9 days incubation period without tryptophan. Y3, Y10 and Y12 strains that were incubated without L-TRP also had the higher ability in the production of IAA than other yeast isolates. The selected yeasts having high IAA production activity were characterized by morphological study and biochemical tests including sugar assimilation and fermentation tests.

326

Ruthenium recovery from acetic acid waste water through sorption with bacterial biosorbent fibers.  

Science.gov (United States)

A fibrous bacterial biosorbent was developed to bind precious metal-organic complexes in batch and column processes. Polyethylenimine (PEI)-modified bacterial biosorbent fiber (PBBF) was prepared by spinning Corynebacterium glutamicum biomass-chitosan blends, coating them with PEI and cross-linking with glutaraldehyde. When an acetic acid waste solution containing 1822.9mg/L Ru was used as a model waste solution, Ru uptake by the PBBF was 16.5 times higher than that of the commercial ion exchange resin, Lewatit MonoPlus M600. The maximum amounts of Ru uptake were 110.5, 16.0 and 6.7mg/g for PBBF, raw biomass, and Lewatit MonoPlus M600, respectively. In a flow-through packed bed, PBBF exhibited the breakthrough time of 42.32h. Therefore, PBBF can be considered as an alternative sorbent for recovery of anionic metal-organic complexes from waste solutions. PMID:23196218

Kwak, In Seob; Won, Sung Wook; Chung, Yong Sik; Yun, Yeoung-Sang

2013-01-01

327

Systematic profiling of indole-3-acetic acid biosynthesis in bacteria using LC-MS/MS.  

Science.gov (United States)

Indole-3-acetic acid (IAA) is produced from tryptophan through five synthesis pathways. A comprehensive method for the quantification of IAA and biosynthesis-related intermediates in a culture medium was developed. Sample preparation was simple with protein precipitation. The analytes were separated on a superficially porous C18 silica column and detected by electrospray ionization-tandem mass spectrometry in the positive ion multiple reaction monitoring mode. The limit of detection was 0.05?M, and the lower limits of quantification ranged from 0.05 to 2?M. The intra-day and inter-day precision and accuracy were less than 13.96%. Ion suppression was observed, and the deuterated internal standards were used to compensate for the matrix effect. The method was applied to analyze changes in tryptophan catabolism in a culture medium of Pseudomonas putida. The proposed method is robust and suitable for the systematic profiling of IAA biosynthesis in culture supernatant. PMID:25746752

Lin, Guang-Huey; Chang, Chung-Yu; Lin, Huei-Ru

2015-04-15

328

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.

329

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

330

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

331

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)

332

Ultrastructure of Sheep Primordial Follicles Cultured in the Presence of Indol Acetic Acid, EGF, and FSH  

Science.gov (United States)

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. PMID:21188166

Andrade, Evelyn Rabelo; Maddox-Hyttel, Poul; Landim-Alvarenga, Fernanda Da Cruz; Viana Silva, José Roberto; Alfieri, Amauri Alcindo; Seneda, Marcelo Marcondes; Figueiredo, José Ricardo; Toniolli, Ricardo

2011-01-01

333

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

334

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

335

2-{2-[(E-(2-Benzoylhydrazin-1-ylidenemethyl]phenoxy}acetic acid  

Directory of Open Access Journals (Sweden)

Full Text Available In the title compound, C16H14N2O4, the dihedral angle between the aromatic rings is 12.45?(6°. The central C(=O—N—N=C bridge is roughly planar (r.m.s. deviation = 0.0346?Å and makes dihedral angles of 13.01?(7 and 0.56?(7° with the attached phenyl and benzene rings, respectively. The acetic acid unit (r.m.s. deviation = 0.0066?Å is twisted from its attached benzene ring [dihedral angle = 19.48?(6°]. In the crystal, molecules are linked by O—H...(O,N, N—H...O and C—H...O hydrogen bonds into sheets lying parallel to the bc plane. A weak aromatic ?–? stacking interaction is also observed [centroid–centroid distance = 3.7330?(7?Å].

Hoong-Kun Fun

2012-07-01

336

Large-scale gaseous acetic acid treatment to disinfect alfalfa seeds inoculated with Escherichia coli.  

Science.gov (United States)

Most outbreaks of foodborne illness related to sprout consumption are ascribed to bacterial contamination of its seeds, and they need disinfection before sprouting. Recently, gaseous acetic acid (GAA) treatment received great attention as a method for seed disinfection. In this study, the effect of GAA treatment on alfalfa seed disinfection was evaluated in a large-scale device to simulate practical applications. Alfalfa seeds (3?kg) inoculated with Escherichia coli were treated with 8.7% (vol/vol) GAA at 55°C for 1-3?h. The population of E. coli was significantly reduced (pgermination ratio of alfalfa seeds was not affected by the treatments under all the conditions. The results indicated that the GAA treatment has a potential for practical application to reduce the risk of foodborne illness caused by consumption of sprouts. PMID:24400985

Nei, Daisuke; Enomoto, Katsuyoshi; Yamamoto, Kazutaka

2014-04-01

337

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

338

THE USE OF ACETIC ACID IONTOPHORESIS IN THE MANAGEMENT OF A SOFT TISSUE INJURY  

Science.gov (United States)

Background: Contusions are common injuries that occur in athletics. If repeated, complications like myositis ossificans can occur. This case describes the examination and treatment of an athlete with an acute soft tissue injury. Objective: To describe the treatment approach used with a hockey player who sustained a soft tissue injury in his upper extremity. Case Description: A 19 year old male sustained a soft tissue injury to his upper arm while playing hockey. The athlete complained of pain rated a 2-3 out of 10. He had a well circumscribed, firm, 8 by 5 centimeter palpable mass present along the lateral arm, and was able to passively flex his elbow from 56° to 135°, demonstrating a 56° loss of elbow extension. Functionally, he was able to perform most activities of daily living, but he was unable to play hockey. Over 29 days, the athlete was treated one time with pulsed ultrasound and ice and nine times with iontophoresis using a 2% acetic acid solution. Additionally, the athlete performed pain-free active range of motion exercises for the elbow. Outcome: Following treatment, the athlete's pain resolved, the palpable mass disappeared, and his passive range of motion at the elbow was 0° to 135°. Most importantly, the athlete was able to resume playing hockey. Discussion: Acetic acid iontophoresis may be a successful intervention for soft tissue injuries of the upper extremity. In this case, it appeared helpful in decreasing the athlete's impairments and contributed to quicker resumption of all functional activities in less time than previously reported in the literature using traditional treatment interventions. PMID:21655380

Ebaugh, David

2010-01-01

339

Highly dispersed supported ruthenium oxide as an aerobic catalyst for acetic acid synthesis  

DEFF Research Database (Denmark)

The increasing need for shifting to renewable feedstocks in the chemical industry has driven research toward using green aerobic, selective oxidation reactions to produce bulk chemicals. Here, we report the use of a ruthenium mixed oxide/hydroxide (RuOx) on different support materials for the selective aerobic oxidation of ethanol to acetic acid. The RuOx was deposited onto different oxide supports using a new gas-phase reaction, which in all cases resulted in homogeneous nanoparticulate films. The RuOx particle size ranged from 0.3 to 1.5nm. The catalytic activity was evaluated on TiO2, Mg6Al2(CO3)(OH)16·4(H2O), MgAl2O4, Na2Ti6O13 nanotubes, ZnO, ?-Al2O3, WO3, CeO2, and Ce0.5Zr0.5O2 supports. The CeO2 supported RuOx had the highest activity, and selectivity toward acetic acid, of all the materials when normalized with respect to Ru-loading. This high activity was independent of the surface area of the support and the loading of RuOx under the tested conditions. This was attributed to the highly uniform size of the RuOx deposits, demonstrating that the deposition is suitable for producing small nanoparticles at high loadings. To elucidate the reason for the promotional effect of CeO2, Ce0.5Zr0.5O2 was investigated as a high oxygen storage capacity support, however, this did not result in higher catalytic activity. The high activity of CeO2 supports compared to the low activity ZnO appear correlated to the presence of high valence Ru(VI) species analogous to that observed in literature.

Laursen, Anders Bo; Gorbanev, Yury

2012-01-01

340

Oxidation of fatty acid may be enhanced by a combination of pomegranate fruit phytochemicals and acetic acid in HepG2 cells  

OpenAIRE

We investigated whether the combination of phytochemicals and acetic acid in the form of fruit vinegar provides an additive effect on changes of mRNA levels related to fatty acid oxidation in human hepatocyte (HepG2). Among the seven fruit vinegars (Rubuscoreanus, Opuntia, blueberry, cherry, red ginseng, mulberry, and pomegranate) studied, treatment of HepG2 with pomegranate vinegar (PV) at concentrations containing 1 mM acetic acid showed the highest in vitro potentiating effect on the mRNA ...

Kim, Ji Yeon; Ok, Elly; Kim, You Jin; Choi, Kyoung-sook; Kwon, Oran

2013-01-01

341

Relationship among lipoperoxides, jasmonates and indole-3-acetic acid formation in potato tuber after wounding.  

Science.gov (United States)

Plant responses to biotic and abiotic stress can be mediated by oxidised products and in this study we analysed the relation among some of them and the growth factor indole-3-acetic acid (IAA). The plant material used was potato tuber sliced below bud and incubated for different lengths of time before analysis. Wounding in potato tuber leads, in a very short time (0-30?min), to the generation of lipid hydroperoxides (LOOH) from polyunsaturated fatty acids (PUFA). These reactive species could cause a subsequent increase of 9 and 13-lipoxygenase (LOX, E.C.1.13.12.12.), analysed by RT-PCR and spectrophotometric assay, LOOH, Jasmonates and IAA all quantified by GC-MS analysis. The activation of 9 and 13-LOX, using different timing, leads to the formation of LOOH with a subsequent generation of jasmonates and IAA as highlighted by the addition on the potato tuber slices of salicylhydroxamic acid (SHAM), an inhibitor of LOX activity. A correlation between jasmonates and IAA resulted by testing their reciprocal influence during wounding in potato tuber. The relationship occurring among each hormone analysed during wounding underlines the fact that the jasmonates level can be regulated in situ and this can suggest a role for these compounds in potato tuber which has been underestimated up to now. PMID:16036342

Reverberi, Massimo; Fanelli, Corrado; Zjalic, Slaven; Briganti, Stefania; Picardo, Mauro; Ricelli, Alessandra; Fabbri, Anna Adele

2005-06-01

342

Acetic acid can catalyze succinimide formation from aspartic acid residues by a concerted bond reorganization mechanism: a computational study.  

Science.gov (United States)

Succinimide formation from aspartic acid (Asp) residues is a concern in the formulation of protein drugs. Based on density functional theory calculations using Ace-Asp-Nme (Ace = acetyl, Nme = NHMe) as a model compound, we propose the possibility that acetic acid (AA), which is often used in protein drug formulation for mildly acidic buffer solutions, catalyzes the succinimide formation from Asp residues by acting as a proton-transfer mediator. The proposed mechanism comprises two steps: cyclization (intramolecular addition) to form a gem-diol tetrahedral intermediate and dehydration of the intermediate. Both steps are catalyzed by an AA molecule, and the first step was predicted to be rate-determining. The cyclization results from a bond formation between the amide nitrogen on the C-terminal side and the side-chain carboxyl carbon, which is part of an extensive bond reorganization (formation and breaking of single bonds and the interchange of single and double bonds) occurring concertedly in a cyclic structure formed by the amide NH bond, the AA molecule and the side-chain C=O group and involving a double proton transfer. The second step also involves an AA-mediated bond reorganization. Carboxylic acids other than AA are also expected to catalyze the succinimide formation by a similar mechanism. PMID:25588215

Takahashi, Ohgi; Kirikoshi, Ryota; Manabe, Noriyoshi

2015-01-01

343

Acetic Acid Can Catalyze Succinimide Formation from Aspartic Acid Residues by a Concerted Bond Reorganization Mechanism: A Computational Study  

Directory of Open Access Journals (Sweden)

Full Text Available Succinimide formation from aspartic acid (Asp residues is a concern in the formulation of protein drugs. Based on density functional theory calculations using Ace-Asp-Nme (Ace = acetyl, Nme = NHMe as a model compound, we propose the possibility that acetic acid (AA, which is often used in protein drug formulation for mildly acidic buffer solutions, catalyzes the succinimide formation from Asp residues by acting as a proton-transfer mediator. The proposed mechanism comprises two steps: cyclization (intramolecular addition to form a gem-diol tetrahedral intermediate and dehydration of the intermediate. Both steps are catalyzed by an AA molecule, and the first step was predicted to be rate-determining. The cyclization results from a bond formation between the amide nitrogen on the C-terminal side and the side-chain carboxyl carbon, which is part of an extensive bond reorganization (formation and breaking of single bonds and the interchange of single and double bonds occurring concertedly in a cyclic structure formed by the amide NH bond, the AA molecule and the side-chain C=O group and involving a double proton transfer. The second step also involves an AA-mediated bond reorganization. Carboxylic acids other than AA are also expected to catalyze the succinimide formation by a similar mechanism.

Ohgi Takahashi

2015-01-01

344

Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Pd(II) complexes of acetic acid and phenyl acetic acid hydrazones of 2-aminonicotinaldehyde  

International Nuclear Information System (INIS)

Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Pd(II) complexes of tridentate Schiff base ligands derived from the condensation of acetic acid hydrazides, with 2-aminonicotinaldehyde have been synthesized. These complexes have been characterized based on analytical, molar conductance, magnetic susceptibility, thermal, electronic and ESR spectral studies. (author). 2 tabs., 3 figs., 2 refs

345

Effect of dissolved oxygen concentration on iron efficiency: Removal of three chloroacetic acids.  

Science.gov (United States)

The monochloroacetic, dichloroacetic and trichloroacetic acid (MCAA, DCAA and TCAA) removed by metallic iron under controlled dissolved oxygen conditions (0, 0.75, 1.52, 2.59, 3.47 or 7.09 mg/L DO) was investigated in well-mixed batch systems. The removal of CAAs increased first and then decreased with increasing DO concentration. Compared with anoxic condition, the reduction of MCAA and DCAA was substantially enhanced in the presence of O2, while TCAA reduction was significantly inhibited above 2.59 mg/L. The 1.52 mg/L DO was optimum for the formation of final product, acetic acid. Chlorine mass balances were 69-102%, and carbon mass balances were 92-105%. With sufficient mass transfer from bulk to the particle surface, the degradation of CAAs was limited by their reduction or migration rate within iron particles, which were dependent on the change of reducing agents and corrosion coatings. Under anoxic conditions, the reduction of CAAs was mainly inhibited by the available reducing agents in the conductive layer. Under low oxic conditions, the increasing reducing agents and thin lepidocrocite layer were favorable for CAA dechlorination. Under high oxic conditions, the redundant oxygen competing for reducing agents and significant lepidocrocite growth became the major restricting factors. Various CAA removal mechanisms could be potentially applied to explaining the effect of DO concentration on iron efficiency for contaminant reduction in water and wastewater treatment. PMID:25697696

Tang, Shun; Wang, Xiao-Mao; Mao, Yu-Qin; Zhao, Yu; Yang, Hong-Wei; Xie, Yuefeng F

2015-04-15

346

Removal of Cu and Zn from acid water by algae  

OpenAIRE

The alga Cyanidium caldarium is capable of precipitating metals from acid water. This study demonstrates that changes in culture and oxidation-reduction conditions may result in a different bioaccumulation of metals. The advantages of metal precipitation are a high degree of metal removal even at low pH and the feasibility of selective metal recovery.

Ahlf, Wolfgang; Calmano, Wolfgang; Erbslo?h, B.

1988-01-01

347

The short-chain fatty acid acetate reduces appetite via a central homeostatic mechanism  

OpenAIRE

Increased intake of dietary carbohydrate that is fermented in the colon by the microbiota has been reported to decrease body weight, although the mechanism remains unclear. Here we use in vivo11C-acetate and PET-CT scanning to show that colonic acetate crosses the blood–brain barrier and is taken up by the brain. Intraperitoneal acetate results in appetite suppression and hypothalamic neuronal activation patterning. We also show that acetate administration is associated with activation of a...

Frost, Gary; Sleeth, Michelle L.; Sahuri-arisoylu, Meliz; Lizarbe, Blanca; Cerdan, Sebastian; Brody, Leigh; Anastasovska, Jelena; Ghourab, Samar; Hankir, Mohammed; Zhang, Shuai; Carling, David; Swann, Jonathan R.; Gibson, Glenn; Viardot, Alexander; Morrison, Douglas

2014-01-01

348

Pexiganan acetate.  

Science.gov (United States)

Pexiganan acetate (MSI 78) is a synthetic cationic peptide (22 amino acids) with antibacterial activity. It is an analogue of magainin 2, which is a host defence peptide isolated from frog skin. The drug is thought to act by disturbing the permeability of the cell membrane or cell wall. Pexiganan acetate has good in vitro activity against Gram-positive and Gram-negative aerobes; 99% of strains were susceptible to the agent using a break-point of 64 mg/L. 89 to 97% of anaerobes were susceptible to pexiganan acetate using the same break-point. After 7 passages in vitro, there was no evidence of resistance to pexiganan acetate among 2 strains of Staphylococcus aureus. In 2 phase III multicentre randomised double-blind trials in diabetic patients with infected foot ulcers, both topical pexiganan acetate 1% and oral ofloxacin 800 mg/day achieved clinical cure or improvement in about 90% of patients. Eradication of pathogens in the 2 studies was achieved in 82% of ofloxacin recipients and 66% of pexiganan acetate recipients at the end of therapy. Limited data indicate that pexiganan acetate is well tolerated. PMID:9878992

Lamb, H M; Wiseman, L R

1998-12-01

349

The toxicity of substituted phenolic compounds to a detoxifying and an acetic acid bacterium.  

Science.gov (United States)

In the detoxifying bacterium Acinetobacter calcoaceticus 69-V and in the acetic acid bacterium Acetobacter methanolicus MB 58, glucose and xylose are oxidized, respectively, via PQQ-dependent membrane-bound dehydrogenases, which are linked to the respiratory chain in a manner enabling energy conservation via electron transport phosphorylation (ETP) in the cytoplasmic membrane. Neither the glucose and gluconic acid nor the xylose and xylonic acid are metabolized. Therefore, measurements of sugar oxidation-driven ATP syntheses ought not to be disturbed by ATP drainage caused by anabolic processes. Studying the effect of substituted phenolic compounds on these energization processes reveals that their toxicity increases with an increasing degree of chlorination and that A. calcoaceticus 69-V is more stable than A. methanolicus MB 58 against chlorinated phenols. On the other hand, A. methanolicus MB 58 is more stable against 2,4-dinitrophenol (2,4-DNP) and 2,4-dichlorophenoxyacetic acid (2,4-D), especially in the acidic pH range, in which the sensitivity of ATP synthesis to the uncouplers is higher than that of respiration. The toxicity caused by protonophoric activities ought to be barely detectable by respiratory and dehydrogenase tests. The luminescence system of Photobacterium phosphoreum tested in the luminescent bacteria test was much more sensitive. This test system should be used as a screening tool and the effects measured must be confirmed by toxicity tests evaluating the stability of bacteria themselves involved in processes of detoxification as well as the production of toxic metabolites, monitored with respect to their velocity and efficiency. PMID:9143455

Loffhagen, N; Härtig, C; Babel, W

1997-04-01

350

Influence of phenolic acids on indole acetic acid production and on the type III secretion system gene transcription in food-associated Pseudomonas fluorescens KM05.  

Science.gov (United States)

The purpose of these investigations was to evaluate the reduction capability of phenolic acids (ferulic, chlorogenic, gallic, and p-coumaric acids) on indole acetic acid synthesis by food-associated Pseudomonas fluorescens KM05. Specific genetic primer for the type III secretion system (TTSS) in P. fluorescens KM05 was designed and the influence of phenolic acids on its expression was investigated. In the work the ferulic and chlorogenic acids at the concentration of 0.02 and 0.04 ?g/ml affected on bacterial growth pattern and the signal molecules production. The phenolic acids, that were appreciable effective against P. fluorescens KM05 indole acetic acid production, significantly suppressed TTSS gene. PMID:24994472

Myszka, Kamila; Schmidt, Marcin T; Olejnik-Schmidt, Agnieszka K; Leja, Katarzyna; Czaczyk, Katarzyna

2014-12-01

351

Mass Transfer and Chemical Reaction Approach of the Kinetics of the Acetylation of Gadung Flour using Glacial Acetic Acid  

Directory of Open Access Journals (Sweden)

Full Text Available Acetylation is one of the common methods of modifying starch properties by introducing acetil (CH3CO groups to starch molecules at low temperatures. While most acetylation is conducted using starch as anhidroglucose source and acetic anhydride or vinyl acetate as nucleophilic agents, this work employ reactants, namely flour and glacial acetic acid. The purpose of this work are to study the effect of pH reaction and GAA/GF mass ratio on the rate of acetylation reaction and to determine its rate constants. The acetylation of gadung flour with glacial acetic acid in the presence of sodium hydroxide as a homogenous catalyst was studied at ambient temperature with pH ranging from 8-10 and different mass ratio of acetic acid : gadung flour (1:3; 1:4; and 1:5. It was found that increasing pH, lead to increase the degree of substitution, while increasing GAA/GF mass ratio caused such decreases in the degree of substitution, due to the hydrolysis of the acetylated starch. The desired starch acetylation reaction is accompanied by undesirable hydrolysis reaction of the acetylated starch after 40-50 minutes reaction time. Investigation of kinetics of the reaction observed that the value of mass transfer rate constant (Kcs is smaller than the surface reaction rate constant (k. Thus, it can be concluded that rate controlling step is mass transfer.  © 2015 BCREC UNDIP. All rights reservedReceived: 7th August 2014; Revised: 8th September 2014; Accepted: 14th September 2014How to Cite: Kumoro, A.C., Amelia, R. (2015. Mass Transfer and Chemical Reaction Approach of the Kinetics of the Acetylation of Gadung Flour using Glacial Acetic Acid. Bulletin of Chemical Reaction Engineering & Catalysis, 10 (1: 30-37. (doi:10.9767/bcrec.10.1.7181.30-37Permalink/DOI: http://dx.doi.org/10.9767/bcrec.10.1.7181.30-37

Andri Cahyo Kumoro

2015-03-01

352

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...

353

INFLUENCE OF DILUTE ACETIC ACID TREATMENTS ON SURVIVAL OF AMERICAN PONDWEED WINTER BUDS IN THE NEVADA IRRIGATION DISTRICT, CALIFORNIA  

Science.gov (United States)

American pondweed (Potamogeton nodosus Poir.) is commonly found in northern California irrigation canals. The purpose of this study was to test the hypothesis that exposure of American pondweed winter buds to dilute acetic acid under field conditions would result in reduced survivorship and subsequ...

354

Resolving the electrospinnability zones and diameter prediction for the electrospinning of the gelatin/water/acetic acid system.  

Science.gov (United States)

The development of suitable biomimetic scaffolds is a fundamental requirement of tissue engineering. Although electrospinning has emerged as an effective method for producing such scaffolds of nanometer-sized fibers, the influence of solution characteristics on the morphology of the resulting nanofibers depends on each polymer solution system. In this study, gelatin nanofibers and microfibers were prepared via electrospinning using mixtures of water and acetic acid at different ratios as solvents. The viscosities of gelatin solutions before electrospinning were analyzed and two different behaviors were found as a function of the solvent composition, taking into account classic models of polymer science. A power law relationship between viscosity and gelatin concentration was found for each solvent system, and an empirical model including the influence of acetic acid was obtained for aqueous systems. Moreover, a ternary diagram considering gelatin, water, and acetic acid mass fractions was constructed as a tool to establish the electrospinnability domains in terms of fiber occurrence and morphology. Also, the isodiametric curves were defined in the fibers region. Finally, in order to correlate the diameter of electrospun nanofibers and the electrospinnability zones, the Berry number was used. However, as its only allows the range of electrospinnability to be established for a fixed solvent composition, a new dimensionless parameter (Bemod) was suggested to take into account all the acetic acid aqueous solutions as a single solvent. PMID:24870557

Erencia, Marisa; Cano, Francisco; Tornero, Jose A; Macanás, Jorge; Carrillo, Fernando

2014-06-24

355

FUNCTIONAL GENOMIC ANALYSIS OF THE AUXIN/INDOLE-3-ACETIC ACID GENE FAMILY MEMBERS IN ARABIDOPSIS THALIANA  

Science.gov (United States)

Auxin regulates various aspects of plant growth and development. The AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) genes encode short-lived transcriptional repressors that are targeted by the TRANSPORT INHIBITOR RESPONSE1/AUXIN RECEPTOR F-BOX proteins. The Aux/IAA proteins regulate auxin-mediated gene expres...

356

GC-MS QUANTIFICATION OF THE METHANOL AND ACETIC ACID CONTENT OF PECTIN USING HEADSPACE SOLID-PHASE MICROEXTRACTION  

Science.gov (United States)

A simple, fast, and direct procedure was developed for the simultaneous determination of the methanol and acetic acid present as esters in the plant cell wall polysaccharide pectin. After base-hydrolysis of esters and acidification of pectin samples, headspace solid-phase microextraction was perfor...

357

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

358

Acetic Acid Sclerotherapy for Treatment of a Bile Leak from an Isolated Bile Duct After Laparoscopic Cholecystectomy  

International Nuclear Information System (INIS)

Bile leak after laparoscopic cholecystectomy is not uncommon, and it mainly occurs from the cystic duct stump and can be easily treated by endoscopic techniques. However, treatment for leakage from an isolated bile duct can be troublesome. We report a successful case of acetic acid sclerotherapy for bile leak from an isolated bile duct after laparoscopic cholecystectomy.

359

Evaluation of Physiological Effects of Acetic Acid Bacteria and Yeast Fermented Non-alchocolic Beverage Consumption in Rat Model  

OpenAIRE

Kombucha is a traditional beverage consumed in various parts of the world. It is made by fermentation of sugared black tea by a consortium of yeasts and acetic acid bacteria. Recent studies have demonstrated that Kombucha possesses antioxidant, antimicrobial, hepatoprotective, nephroprotective and hypocholesterolaemic properties. Microbial composition of Kombucha association is highly variable therefore the chemical composition of obtained beverage can vary a lot...

Semjonovs, P.; Denina, I.; Linde, R.

2014-01-01

360

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

International Nuclear Information System (INIS)

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 deg. C, 1 min for the first step, and 300 deg. 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

361

Integrated phospholipidomics and transcriptomics analysis of Saccharomyces cerevisiae with enhanced tolerance to a mixture of acetic acid, furfural, and phenol  

Science.gov (United States)

A mixture of acetic acid, furfural and phenol (AFP), three representative lignocellulose derived inhibitors, significantly inhibited the growth and bioethanol production of Saccharomyces cerevisiae. In order to uncover mechanisms behind the enhanced tolerance of an inhibitor-tolerant S.cerevisiae s...

362

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

Directory of Open Access Journals (Sweden)

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

363

Effects of pH and acetic acid on glucose and xylose metabolism by a genetically engineered ethanologenic Escherichia 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. The patented, genetically engineered, ethanologen Escherichia coli B (pLOI297) exhibits high-performance characteristics with respect to both yield and productivity in xylose-rich lab media. In addition to producing monomer sugar residues, thermochemical processing of biomass is known to produce substances that are inhibitory to both yeast and bacteria. During prehydrolysis, acetic acid is formed as a consequence of the deacetylation of the acetylated pentosan. Our investigations have shown that the acetic acid content of hemicellulose hydrolysates from a variety of biomass/waste materials was in the range 2-10 g/L (33-166 mM). Increasing the reducing sugar concentration by evaporation did not alter the acetic acid concentration. Acetic acid toxicity is pH dependent. By virtue of its ability to traverse the cell membrane freely, the undissociated (protonated) form of acetic acid (HAc) acts as a membrane protonophore and causes its inhibitory effect by bringing about the acidification of the cytoplasm. With recombinant E. coli B, the pH range for optimal growth with glucose and xylose was 6.4-6.8. With glucose, the pH optimum for ethanol yield and volumetric productivity was 6.5, and for xylose it was 6.0 and 6.5, respectively. However, the decrease in growth and fermentation efficiency at pH 7 is not significant. At pH 7, only 0.56% of acetic acid is undissociated, and at 10 g/L, neither the ethanol yield nor the maximum volumetric productivity, with glucose or xylose, is significantly decreased. The "uncoupling" effect of HAc is more pronounced with xylose and the potency of HAc is potentiated in a minimal salts medium. Controlling the pH at 7 provided an effective means of circumventing acetic acid toxicity without significant loss in fermentation performance of the recombinant biocatalyst. PMID:8323264

Lawford, H G; Rousseau, J D

1993-01-01

364

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 liqu nucleobases in the ionic liquids ionicity.

365

Preparation of cellouronic acids and partially acetylated cellouronic acids by TEMPO/NaClO oxidation of water-soluble cellulose acetate.  

Science.gov (United States)

Water-soluble cellulose acetates with a degree of substitution (DS) of 0.5, prepared by partial deacetylation of cellulose acetate of DS=2.5, were oxidized with catalytic amount of 2,2,6,6,-tetramethyl-1-piperidinyloxy radical (TEMPO), sodium hypochlorite, and sodium bromide to provide useful cellouronic acids. The oxidation was conducted at a constant pH of 10 and at 2 degrees C to avoid the occurrence of side products. Whereas only the primary hydroxyl groups of cellulose acetate were oxidized, a variable degree of oxidation (DO) resulted in a range of 0.33 to 1.0, depending on the concentration in sodium hypochlorite. Thus, polyglucuronic acid as well as partially acetylated cellouronic acid, having a range of DO were obtained. PMID:15003022

Gomez-Bujedo, Silvia; Fleury, Etienne; Vignon, Michel R

2004-01-01

366

Acetobacter fabarum sp. nov., an acetic acid bacterium from a Ghanaian cocoa bean heap fermentation.  

Science.gov (United States)

Six acetic acid bacterial isolates, obtained during a study of the microbial diversity of spontaneous fermentations of Ghanaian cocoa beans, were subjected to a polyphasic taxonomic study. (GTG)(5)-PCR fingerprinting grouped the isolates together, but they could not be identified using this method. Phylogenetic analysis based on 16S rRNA gene sequences allocated the isolates to the genus Acetobacter and revealed Acetobacter lovaniensis, Acetobacter ghanensis and Acetobacter syzygii to be nearest neighbours. DNA-DNA hybridizations demonstrated that the isolates belonged to a single novel genospecies that could be differentiated from its phylogenetically nearest neighbours by the following phenotypic characteristics: no production of 2-keto-D-gluconic acid from D-glucose; growth on methanol and D-xylose, but not on maltose, as sole carbon sources; no growth on yeast extract with 30% D-glucose; and weak growth at 37 degrees C. The DNA G+C contents of four selected strains were 56.8-58.0 mol%. The results obtained prove that the isolates should be classified as representatives of a novel Acetobacter species, for which the name Acetobacter fabarum sp. nov. is proposed. The type strain is strain 985(T) (=R-36330(T) =LMG 24244(T) =DSM 19596(T)). PMID:18768626

Cleenwerck, Ilse; Gonzalez, Angel; Camu, Nicholas; Engelbeen, Katrien; De Vos, Paul; De Vuyst, Luc

2008-09-01

367

Lactobacillus acidophilus NCFM affects vitamin E acetate metabolism and intestinal bile acid signature in monocolonized mice  

DEFF Research Database (Denmark)

Mono-colonization of germ-free (GF) mice enables the study of specific bacterial species in vivo. Lactobacillus acidophilus is a probiotic strain, however many of the mechanisms behind its health-promoting effect remain unsolved. Here, we studied the effects of Lactobacillus acidophilus NCFMTM (NCFM) on the intestinal metabolome (jejunum, caecum, and colon) in mice by comparing NCFM mono-colonized (MC) mice with GF mice using liquid chromatography coupled to mass-spectrometry (LC-MS). The study adds to existing evidence that NCFM in vivo affects the bile acid signature of mice by deconjugation and dehydroxylation of bile acids. Furthermore, we confirmed that carbohydrate metabolism is affected by NCFM in the mouse intestine. Especially, the digestion of larger carbohydrates (penta- and tetrasaccharides) was increased in MC mice. Interestingly, we also found vitamin E (?-tocopherol acetate) in higher levels in the intestine of GF mice compared to MC mice, suggesting that NCFM either metabolizes the compound orindirectly affects the absorption by changing the metabolome in the intestine. The use of NCFM to increase the uptake of vitamin E supplements in humans and animals is a highly relevant topic for further research.

Roager, Henrik Munch; Sulek, Karolina

2014-01-01

368

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

369

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

International Nuclear Information System (INIS)

9-Vinyladenine was synthesized as a novel functional monomer for molecular imprinting techniques and its structure was established with elemental analysis and 1H NMR spectroscopy. The binding mechanism between this functional monomer 9-vinyladenine and the plant hormone 1H-indole-3-acetic acid in acetonitrile was studied with UV-vis spectrophotometry. Based on this study, using 1H-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 1H-indole-3-acetic acid, 1H-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 1H-indole-3-acetic acid than 1H-indole-3-butyric acid or kinetin. The membrane prepared with 9-vinyladenine also took on higher permselectivity for 1H-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 1H-indole-3-acetic acid or for the preparation of a molecularly imprinted polymer sensor for molecularly imprinted polymer sensor for the analysis of 1H-indole-3-acetic acid in plant samples

370

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

371

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

International Nuclear Information System (INIS)

Three types of culture experiments using paddy rice (Oryza sativa L.) were performed to examine root-uptake of 14C 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 14C radioactivity in the plant, mediums, and atmospheric carbon dioxide (14CO2) in the chamber were determined, and the distribution of 14C 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 14C radioactivity, but the upper root which did not have contact with the solution had none. There were also 14C radioactivity in the grains and roots in the wet culture experiment. Results of the chamber experiment showed that 14CO2 gas was released from the culture solution in both types of cultures. Results indicated that the 14C-acetic acid absorbed by rice plant through its root would be very small. Most of the 14C-acetic acid was transformed into gaseous forms either in the culture solution or rhizosphere. A relatively longer time would be needed to assimilate 14C derived from acetic acid to grain parts after it was once absorbed by the shoot through the root. Availability of 14C for the plant in sand culture was considered to beplant 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.

372

Cartilage and bone malformations in the head of zebrafish (Danio rerio) embryos following exposure to disulfiram and acetic acid hydrazide  

International Nuclear Information System (INIS)

In order to investigate teratogenic effects, especially on cartilage and bone formation, zebrafish embryos were exposed for 144 h to the dithiocarbamate pesticide disulfiram (20–320 ?g/L) and acetic acid hydrazide (0.375–12 g/L), a degradation product of isoniazid. After fixation and full-mount staining, disulfiram could be shown to induce strong cartilage malformations after exposure to ? 80 ?g/L, whereas acetic acid hydrazide caused cartilage alterations only from 1.5 g/L. Undulating notochords occurred after exposure to disulfiram even at the lowest test concentration of 20 ?g/L, whereas at the two lowest concentrations of acetic acid hydrazide (0.375 and 0.75 g/L) mainly fractures of the notochord were observed. Concentrations of acetic acid hydrazide ? 1.5 g/L resulted in undulated notochords similar to disulfiram. Cartilages and ossifications of the cranium, including the cleithrum, were individually analyzed assessing the severity of malformation and the degree of ossification in a semi-quantitative approach. Cartilages of the neurocranium such as the ethmoid plate proved to be more stable than cartilages of the pharyngeal skeleton such as Meckel's cartilage. Hence, ossification proved significantly more susceptible than cartilage. The alterations induced in the notochord as well as in the cranium might well be of ecological relevance, since notochord malformation is likely to result in impaired swimming and cranial malformation might compromise regular food uptake. - Highlights: ? Disulfiram and acetic acid hydrazide as notochord, cartilage and bone teratogens ? Zebrafish embryos to model effects on single cartilages and bones in the head ? LC50 calculation and head length measurements after six days post-fertilization ? Lethality, head length and teratogenic effects are dose-dependent. ? Cartilages of the neurocranium are the most stable elements in the head

373

Cartilage and bone malformations in the head of zebrafish (Danio rerio) embryos following exposure to disulfiram and acetic acid hydrazide  

Energy Technology Data Exchange (ETDEWEB)

In order to investigate teratogenic effects, especially on cartilage and bone formation, zebrafish embryos were exposed for 144 h to the dithiocarbamate pesticide disulfiram (20–320 ?g/L) and acetic acid hydrazide (0.375–12 g/L), a degradation product of isoniazid. After fixation and full-mount staining, disulfiram could be shown to induce strong cartilage malformations after exposure to ? 80 ?g/L, whereas acetic acid hydrazide caused cartilage alterations only from 1.5 g/L. Undulating notochords occurred after exposure to disulfiram even at the lowest test concentration of 20 ?g/L, whereas at the two lowest concentrations of acetic acid hydrazide (0.375 and 0.75 g/L) mainly fractures of the notochord were observed. Concentrations of acetic acid hydrazide ? 1.5 g/L resulted in undulated notochords similar to disulfiram. Cartilages and ossifications of the cranium, including the cleithrum, were individually analyzed assessing the severity of malformation and the degree of ossification in a semi-quantitative approach. Cartilages of the neurocranium such as the ethmoid plate proved to be more stable than cartilages of the pharyngeal skeleton such as Meckel's cartilage. Hence, ossification proved significantly more susceptible than cartilage. The alterations induced in the notochord as well as in the cranium might well be of ecological relevance, since notochord malformation is likely to result in impaired swimming and cranial malformation might compromise regular food uptake. - Highlights: ? Disulfiram and acetic acid hydrazide as notochord, cartilage and bone teratogens ? Zebrafish embryos to model effects on single cartilages and bones in the head ? LC50 calculation and head length measurements after six days post-fertilization ? Lethality, head length and teratogenic effects are dose-dependent. ? Cartilages of the neurocranium are the most stable elements in the head.

Strecker, Ruben, E-mail: Ruben.Strecker@cos.uni-heidelberg.de [Aquatic Ecology and Toxicology Section, Center for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, D-69120 Heidelberg (Germany); Weigt, Stefan, E-mail: stefan.weigt@merckgroup.com [Institute of Toxicology, Merck KGaA, 64293 Darmstadt (Germany); Braunbeck, Thomas, E-mail: braunbeck@uni-hd.de [Aquatic Ecology and Toxicology Section, Center for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, D-69120 Heidelberg (Germany)

2013-04-15

374

Evaluation of sanitizing efficacy of acetic acid on Piper betle leaves and its effect on antioxidant properties.  

Science.gov (United States)

The sanitizing efficacy of acetic acid and its effect on health beneficial properties of Piper betle leaves were determined. Betel leaves artificially inoculated with Aeromonas, Salmonella and Yersinia were subjected to organic acid (citric acid, acetic acid and lactic acid) treatment. Pathogen populations reduced by 4 log upon individual inoculation and up to 2 log in a mixed cocktail following treatment with 2% acetic acid during storage up to 20 h at 28 degrees C, indicating a residual antimicrobial effect on pathogen during storage. Antioxidant potential ethanolic extracts of both raw and treated P. betle leaves were assayed for free radical scavenging activities against 2,2-diphenyl-1-picryhydrazyl. Polyphenols, flavonoids and the reducing power of treated and untreated P. betle were also compared. No significant (P>0.05) changes were observed in antioxidant status; flavonoids, polyphenols and reducing power of treated betel leaves. Results indicate the feasibility of a simple intervention strategy for inactivating pathogens in edible leaves of P. betle. PMID:19670009

Singla, Richu; Ganguli, Abhijit; Ghosh, Moushumi; Sohal, Sapna

2009-01-01

375

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

376

Antibacterial Power of Sodium Hypochlorite Combined with Surfactants and Acetic Acid  

Scientific Electronic Library Online (English)

Full Text Available 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.

377

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

378

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

379

Indole-3-butyric acid induces lateral root formation via peroxisome-derived indole-3-acetic acid and nitric oxide.  

Science.gov (United States)

Controlled plant growth requires regulation through a variety of signaling molecules, including steroids, peptides, radicals of oxygen and nitrogen, as well as the 'classical' phytohormone groups. Auxin is critical for the control of plant growth and also orchestrates many developmental processes, such as the formation of new roots. It modulates root architecture both slowly, through actions at the transcriptional level and, more rapidly, by mechanisms targeting primarily plasma membrane sensory systems and intracellular signaling pathways. The latter reactions use several second messengers, including Ca(2+) , nitric oxide (NO) and reactive oxygen species (ROS). Here, we investigated the different roles of two auxins, the major auxin indole-3-acetic acid (IAA) and another endogenous auxin indole-3-butyric acid (IBA), in the lateral root formation process of Arabidopsis and maize. This was mainly analyzed by different types of fluorescence microscopy and inhibitors of NO production. This study revealed that peroxisomal IBA to IAA conversion is followed by peroxisomal NO, which is important for IBA-induced lateral root formation. We conclude that peroxisomal NO emerges as a new player in auxin-induced root organogenesis. In particular, the spatially and temporally coordinated release of NO and IAA from peroxisomes is behind the strong promotion of lateral root formation via IBA. PMID:23795714

Schlicht, Markus; Ludwig-Müller, Jutta; Burbach, Christian; Volkmann, Dieter; Baluska, Frantisek

2013-10-01

380

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

Science.gov (United States)

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

381

Attempting to monitor the incorporation of deuterium into indole-3-acetic acid and tryptophan in Zea mays grown on deuterium oxide labeled water  

International Nuclear Information System (INIS)

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 ampersand 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

382

??????????????????? 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

383

Exchange of atmospheric formic and acetic acids with trees and crop plants under controlled chamber and purified air conditions  

Science.gov (United States)

We investigated the exchange of formic and acetic acids between the atmosphere and various tree species such as beech ( Fagus sylvatica L.), ash ( Fraxinus excelsior L.), spruce ( Picea abies L.) Karst, holm oak ( Quercus ilex L.), and birch ( Betula pendula L.). and some crop-plant species such as corn ( Zea mays, var. Banjo), pea ( Pisum sativum, var. Solara), barley ( Hordeum vulgare, var. Igri) and oat (Avena sativa, var. Wiesel). All experiments were done with dynamic enclosures flushed with purified oxidant-free air, containing only low or controlled amounts of the two acids. Significant and light-triggered emission of both acids from all tree species was observed. For one tree species (ash) a seasonal large increase in fall due to early leaf decomposition was found. The standard emission factors (30°C and PAR=1000 ?mol m 2 s -1) given as (nmol m -2 min -1) for acetic and formic acids, respectively, were 8.1 and 29.7 (ash, autumn), 1.0 and 3.3 (ash, summer), 0.9 and 1.4 (beech), 0.7 and 1.45 (spruce), 1.9 and 2.4 (Holm oak) and 1.7 and 6.7 (birch). Rough estimation of global annual emissions range between 20 and 130 Gmol formic acid and 10 and 33 Gmol acetic acid. These numbers reflect a 15-30% contribution by forest emissions to the continental organic acid budget. As compared to the global total NMHC emissions low molecular weight organic acids are of minor importance. In contrast to the trees, none of the crop-plant species investigated showed an emission, but always a clear deposition of both acids. Both emission from trees as well as uptake by the agricultural plants could be related to transpiration rates and leaf conductances.

Kesselmeier, J.; Bode, K.; Gerlach, C.; Jork, E.-M.

384

Radiation-induced copolymerizations of perfluorovinyl acetic acid and its methyl ester with ?-olefin  

International Nuclear Information System (INIS)

Homopolymerizations and copolymerizations of perfluorovinyl acetic acid (FVA) and its methyl ester (MFVA) were carried out by ? radiation at a temperature of 250C, a dose rate of 1 x 106 rad/hr, and FVA/?-olefin and MFVA/?-olefin ratios of 10/90-90/10 in the monomer mixture. FVA and MFVA gave small quantities of brown and greasy low-molecular-weight homopolymers. The polymerization rates of both FVA and MFVA were extremely small, as shown by the maximum G value of monomer consumption of 12. FVA and MFVA reacted with ?-olefin to form waxlike copolymers. The copolymerization rates of both FVA and MFVA with ?-olefin were remarkably larger than those of the homopolymerizations, particularly with ethylene. The polymer compositions of FVA/ethylene or MFVA/ethylene were nearly 1/2 over a wide range of the monomer compositions. The Mayo-Lewis method gave negative r1 (FVA) and r1(MFVA). The polymer composition curves could be well interpreted by introducing the penultimate model

385

The cardiovascular effect of the uremic solute indole-3 acetic Acid.  

Science.gov (United States)

In CKD, uremic solutes may induce endothelial dysfunction, inflammation, and oxidative stress, leading to increased cardiovascular risk. We investigated whether the uremic solute indole-3 acetic acid (IAA) predicts clinical outcomes in patients with CKD and has prooxidant and proinflammatory effects. We studied 120 patients with CKD. During the median study period of 966 days, 29 patients died and 35 experienced a major cardiovascular event. Kaplan-Meier analysis revealed that mortality and cardiovascular events were significantly higher in the higher IAA group (IAA>3.73 µM) than in the lower IAA group (IAAalbumin; diastolic BP and history of cardiovascular disease; and uremic toxins p-cresyl sulfate and indoxyl sulfate. Notably, IAA level remained predictive of mortality when adjusted for CKD stage. IAA levels were positively correlated with markers of inflammation and oxidative stress: C-reactive protein and malondialdehyde, respectively. In cultured human endothelial cells, IAA activated an inflammatory nongenomic aryl hydrocarbon receptor (AhR)/p38MAPK/NF-?B pathway that induced the proinflammatory enzyme cyclooxygenase-2. Additionally, IAA increased production of endothelial reactive oxygen species. In conclusion, serum IAA may be an independent predictor of mortality and cardiovascular events in patients with CKD. In vitro, IAA induces endothelial inflammation and oxidative stress and activates an inflammatory AhR/p38MAPK/NF-?B pathway. PMID:25145928

Dou, Laetitia; Sallée, Marion; Cerini, Claire; Poitevin, Stéphane; Gondouin, Bertrand; Jourde-Chiche, Noemie; Fallague, Karim; Brunet, Philippe; Calaf, Raymond; Dussol, Bertrand; Mallet, Bernard; Dignat-George, Françoise; Burtey, Stephane

2015-04-01

386

Nitric oxide metabolism and indole acetic acid biosynthesis cross-talk in Azospirillum brasilense SM.  

Science.gov (United States)

Production of nitric oxide (NO) and the presence of NO metabolism genes, nitrous oxide reductase (nosZ), nitrous oxide reductase regulator (nosR) and nitric oxide reductase (norB) were identified in the plant-associated bacterium (PAB) Azospirillum brasilense SM. NO presence was confirmed in all overexpressing strains, while improvement in the plant growth response of these strains was mediated by increased NO and indole-3-acetic acid (IAA) levels in the strains. Electron microscopy showed random distribution to biofilm, with surface colonization of pleiomorphic Azospirilla. Quantitative IAA estimation highlighted a crucial role of nosR and norBC in regulating IAA biosynthesis. The NO quencher and donor reduced/blocked IAA biosynthesis by all strains, indicating their common regulatory role in IAA biosynthesis. Tryptophan (Trp) and l-Arginine (Arg) showed higher expression of NO genes tested, while in the case of ipdC, only Trp and IAA increased expression, while Arg had no significant effect. The highest nosR expression in SMnosR in the presence of IAA and Trp, along with its 2-fold IAA level, confirmed the relationship of nosR overexpression with Trp in increasing IAA. These results indicate a strong correlation between IAA and NO in A. brasilense SM and suggest the existence of cross-talk or shared signaling mechanisms in these two growth regulators. PMID:25700632

Koul, Vatsala; Tripathi, Chandrakant; Adholeya, Alok; Kochar, Mandira

2015-04-01

387

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

Science.gov (United States)

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

388

Intraperitoneal administration of butyrate prevents the severity of acetic acid colitis in rats.  

Science.gov (United States)

Intrarectal infusion of butyrate improves colorectal disorders including ulcerative colitis (UC). However, it is not established whether systemically administered butyrate benefits such patients. The current study aimed at exploring and comparing the potential of intraperitoneally, intrarectally, and orally administered butyrate against acetic acid (AA)-induced UC in rats. Intrarectal administration of 2 ml of 50% AA was done after or without prior treatment of rats for 7 consecutive days with 100 mg/kg sodium butyrate (SB) intraperitoneally, intrarectally, or orally. Rats were sacrificed after 48 h of AA-treatment. Subsequently, colon sections were processed routinely for histopathological examination. We clinically observed diarrhea, loose stools, and hemoccult-positive stools, and histologically, epithelial loss and ulceration, crypt damage, goblet cell depletion, hemorrhage, and mucosal infiltration of inflammatory cells. The changes were significantly reduced by intraperitoneal, intrarectal, or oral butyrate, with intraperitoneal butyrate exhibiting the highest potency. It is concluded that intraperitoneal administration of butyrate abrogates the lesions of AA-induced UC and its potency surpasses that of intrarectal or oral butyrate. PMID:25743124

Malago, Joshua J; Sangu, Catherine L

2015-03-01

389

A computational NQR study on the hydrogen-bonded lattice of cytosine-5-acetic acid.  

Science.gov (United States)

A computational study at the level of density functional theory (DFT) employing 6-311++G** standard basis set was carried out to evaluate nuclear quadrupole resonance (NQR) spectroscopy parameters in cytosine-5-acetic acid (C5AA). Since the electric field gradient (EFG) tensors are very sensitive to the electrostatic environment at the sites of quadruple nuclei, the most possible interacting molecules with the target one were considered in a five-molecule model system of C5AA using X-ray coordinates transforming. The hydrogen atoms positions were optimized and two model systems of original and H-optimized C5AA were considered in NQR calculations. The calculated EFG tensors at the sites of (17)O, (14)N, and (2)H nuclei were converted to their experimentally measurable parameters, quadrupole coupling constants and asymmetry parameters. The evaluated NQR parameters reveal that the nuclei in original and H-optimized systems contribute to different hydrogen bonding (HB) interaction. The comparison of calculated parameters between optimized isolated gas-phase and crystalline monomer also shows the relationship between the structural deformation and NQR parameters in C5AA. The basis set superposition error (BSSE) calculations yielded no significant errors for employed basis set in the evaluation of NQR parameters. All the calculations were performed by Gaussian 98 package of program. PMID:17926341

Mirzaei, Mahmoud; Hadipour, Nasser L

2008-04-15

390

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)

391

Nadroparin sodium activates Nrf2/HO-1 pathway in acetic acid-induced colitis in rats.  

Science.gov (United States)

Effects of nadroparin sodium, a low molecular weight heparin, in colitis was investigated by analyzing proteins implicated in nuclear factor E2-related factor-2/heme oxygenase-1 (Nrf2/HO-1) and nuclear factor kappa B (NF-?B) pathways. Twenty-eight rats were used. Colitis was induced by acetic acid (AA). Nadroparin sodium was given to prevention and treatment groups in addition to AA. Colitis was assessed histologically and levels of proteins were analyzed with Western blot. Nadroparin not only prevented and ameliorated the AA-induced colitis histopathologically but also decreased expression of colon NF-?B, activator protein-1, cyclooxygenase-2, tumor necrosis factor-alpha, and IL-6, which were significantly increased in group AA compared to control. The accumulation of Nrf2 in nuclear fraction and HO-1 found low in group AA was increased with nadroparin (p?nadroparin prevention and treatment (p?Nadroparin sodium has both protective and therapeutic effects against colonic inflammation via exerting anti-oxidative and anti-inflammatory effects by modulating Nrf2/HO-1 and NF-?B pathways. PMID:22350949

Yalniz, Mehmet; Demirel, Ulvi; Orhan, Cemal; Bahcecioglu, Ibrahim Halil; Ozercan, Ibrahim Hanefi; Aygun, Cem; Tuzcu, Mehmet; Sahin, Kazim

2012-06-01

392

The effect of intracerebroventricular injection of histamine in visceral nociception induced by acetic acid in rats  

Directory of Open Access Journals (Sweden)

Full Text Available Objective : This study was designed to investigate the role of brain histamine and H1 and H2 receptors in mediating the central perception of visceral pain in rats. Materials and Methods : In conscious rats implanted with a lateral brain ventricle cannula, the effect of intracerebroventricular (i.c.v. injection of histamine (2.5, 10, and 40 ?g, and chlorpheniramine and ranitidine at the same doses of 5, 20, and 80 ?g were investigated on visceral pain. Visceral nociception induced by intraperitoneal (i.p. injection of acetic acid (1 mL, 1%, and the number of complete abdominal wall muscle contractions accompanied with stretching of hind limbs (writhes were counted for 1 h. Results : Histamine at doses of 10 and 40 ?g and chlorpheniramine and ranitidine at the same doses of 20 and 80 ?g, significantly decreased the numbers of writhes (P < 0.05. Pretreatment with chlorpheniramine and ranitidine at the same dose of 80 ?g, significantly prevented histamine (40 ?g-induced antinociception (P < 0.05. Conclusion : The results of this study suggest that brain histamine may be involved in modulation of visceral antinociception through both central H 1 and H 2 receptors.

Zanboori Ali

2010-01-01

393

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

394

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

Directory of Open Access Journals (Sweden)

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

395

Production of the phytohormone indole-3-acetic acid by estuarine species of the genus Vibrio.  

Science.gov (United States)

Strains of Vibrio spp. isolated from roots of the estuarine grasses Spartina alterniflora and Juncus roemerianus produce the phytohormone indole-3-acetic acid (IAA). The colorimetric Salkowski assay was used for initial screening of IAA production. Gas chromatography-mass spectroscopy (GC-MS) was then employed to confirm and quantify IAA production. The accuracy of IAA quantification by the Salkowski assay was examined by comparison to GC-MS assay values. Indole-3-acetamide, an intermediate in IAA biosynthesis by the indole-3-acetamide pathway, was also identified by GC-MS. Multilocus sequence typing of concatenated 16S rRNA, recA, and rpoA genes was used for phylogenetic analysis of environmental isolates within the genus Vibrio. Eight Vibrio type strains and five additional species-level clades containing a total of 16 environmental isolates and representing five presumptive new species were identified as IAA-producing Vibrio species. Six additional environmental isolates similar to four of the Vibrio type strains were also IAA producers. To our knowledge, this is the first report of IAA production by species of the genus Vibrio or by bacteria isolated from an estuarine environment. PMID:19218411

Gutierrez, Casandra K; Matsui, George Y; Lincoln, David E; Lovell, Charles R

2009-04-01

396

Microstructural characterization of oxide film formed on NiTi by anodization in acetic acid  

International Nuclear Information System (INIS)

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 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 TiO2) 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

397

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

398

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

399

Gluconobacter thailandicus sp. nov., an acetic acid bacterium in the alpha-Proteobacteria.  

Science.gov (United States)

Four strains of acetic acid bacteria were isolated from flowers collected in Thailand. In phylogenetic trees based on 16S rRNA gene sequences and 16S-23S rDNA internal transcribed spacer (ITS) region sequences, the four isolates were located in the lineage of the genus Gluconobacter and constituted a separate cluster from the known Gluconobacter species, Gluconobacter oxydans, Gluconobacter cerinus, and Gluconobacter frateurii. In addition, the isolates were distinguished from the known species by restriction analysis of 16S-23S rDNA ITS region PCR products using three restriction endonucleases Bsp1286I, MboII, and AvaII. The DNA base composition of the isolates ranged from 55.3-56.3 mol% G+C. The four isolates constituted a taxon separate from G. oxydans, G. cerinus, and G. frateurii on the basis of DNA-DNA similarities. Morphologically, physiologically, and biochemically, the four isolates were very similar to the type strains of G. oxydans, G. cerinus, and G. frateurii; however, the isolates were discriminated in their growth at 37 degrees C from the type strains of G. cerinus and G. frateurii, and in their growth on L-arabitol and meso-ribitol from the type strain of G. oxydans. The isolates showed no acid production from myo-inositol or melibiose, which differed from the type strains of the three known species. The major ubiquinone homologue was Q-10. On the basis of the results obtained, Gluconobacter thailandicus sp. nov. was proposed for the four isolates. The type strain is isolate F149-1(T) (=BCC 14116(T)=NBRC 100600(T)=JCM 12310(T)=TISTR 1533(T)=PCU 225(T)), which had 55.8 mol% G+C, isolated from a flower of the Indian cork tree (Millingtonia hortensis) collected in Bangkok, Thailand. PMID:15486825

Tanasupawat, Somboon; Thawai, Chitti; Yukphan, Pattaraporn; Moonmangmee, Duangtip; Itoh, Takashi; Adachi, Osao; Yamada, Yuzo

2004-06-01

400

Biosynthesis of Indole-3-Acetic Acid by the Gall-inducing Fungus Ustilago esculenta  

Directory of Open Access Journals (Sweden)

Full Text Available Ustilago esculenta incites the formation of an edible gall and prevents inflorescence and seed production in the aquatic perennial grass, Zizania latifolia. As compared to the healthy tissues, the edible galls had higher amounts of indole-3-acetic acid (IAA, which could be synthesized from the host plant and/or the fungal pathogen. In this study we investigated the ability for IAA production by U. esculenta. The production of IAA in culture by U. esculenta was solely dependent on the presence of tryptophan. The addition of thiamine (vitamin B1 to medium greatly enhanced fungal growth, whereas IAA production was completely inhibited. Maximum amount of IAA (ca.1.0 ?g mL-1 was obtained after 8-day incubation. The production of IAA was highly correlated with the amount of tryptophan. The optimum temperature for IAA production ranged from 20 to 25 ° C. However, IAA production was significantly reduced when fungus was grown in the fluctuated temperatures, indicating that a constant temperature has a profound effect on IAA production. The corn smut pathogen U. maydis also synthesized IAA using tryptophan and accumulated a maximum amount of IAA (ca.1.2 ?g mL-1 at day 3, then production was declined steadily thereafter. In contrast, the sugarcane smut pathogen U. scitaminea produced less amount of IAA (ca.0.53 ?g mL-1 compared to other two species. In addition to tryptophan, U. esculenta apparently could convert indole-3-acetamide (IAAld, indole-pyruate (IPA and indole-lactic acid (ILA into IAA. However, indole-3-acetamide (IAM was evidently not a suitable precursor for IAA production. The results suggest that biosynthesis of IAA in U. esculenta from tryptophan proceeds through IPA and IAAld.

Kuang R. Chung

2004-01-01

401

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

Energy Technology Data Exchange (ETDEWEB)

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

Zinder, S.H.

1994-02-01

402

The short-chain fatty acid acetate reduces appetite via a central homeostatic mechanism.  

Science.gov (United States)

Increased intake of dietary carbohydrate that is fermented in the colon by the microbiota has been reported to decrease body weight, although the mechanism remains unclear. Here we use in vivo(11)C-acetate and PET-CT scanning to show that colonic acetate crosses the blood-brain barrier and is taken up by the brain. Intraperitoneal acetate results in appetite suppression and hypothalamic neuronal activation patterning. We also show that acetate administration is associated with activation of acetyl-CoA carboxylase and changes in the expression profiles of regulatory neuropeptides that favour appetite suppression. Furthermore, we demonstrate through (13)C high-resolution magic-angle-spinning that (13)C acetate from fermentation of (13)C-labelled carbohydrate in the colon increases hypothalamic (13)C acetate above baseline levels. Hypothalamic (13)C acetate regionally increases the (13)C labelling of the glutamate-glutamine and GABA neuroglial cycles, with hypothalamic (13)C lactate reaching higher levels than the 'remaining brain'. These observations suggest that acetate has a direct role in central appetite regulation. PMID:24781306

Frost, Gary; Sleeth, Michelle L; Sahuri-Arisoylu, Meliz; Lizarbe, Blanca; Cerdan, Sebastian; Brody, Leigh; Anastasovska, Jelena; Ghourab, Samar; Hankir, Mohammed; Zhang, Shuai; Carling, David; Swann, Jonathan R; Gibson, Glenn; Viardot, Alexander; Morrison, Douglas; Louise Thomas, E; Bell, Jimmy D

2014-01-01

403

Study of perrhenate ions behaviour in acetic-acid medium by thin-layer chromatography method and infrared spectroscopy  

International Nuclear Information System (INIS)

Thin-layer chromatographic behaviour of perrhenate ions has been studied in an acetate solution of different concentration, used as a mobile phase, on aluminium and silicon oxides and on their mixture used as sorbent-carriers. It has been established that in acetate solutions within the range 0.2-2.0 gmol/l (pH 2.0-2.5) rhenium (7) ions form on sorbent-carriers two zones with different Rf values. Gas liquid chromatography reveals traces of acetaldehyde (2.1x10-10 gmol/l) in acetic acid which means that no interaction with rhenium takes place under chromatographic conditions. In order to understand why two zones of perrhenate ions are formed only in a certain concentration range of acetic acid, chemically pure silicon oxide has been used as a carrier along with aluminium, as well as their mixtures. In this case also two zones have been detected with the same Rf values which eliminates the possible effect of the carrier. Comparison of infrared spectra indicates that two zones formed during the chromatographic process correspond to different states of rhenium

404

Evaluation of nitric and acetic acid resistance of cement mortars containing high-volume black rice husk ash.  

Science.gov (United States)

This paper presents the performance of cement mortar containing black rice husk ash (BRHA) under nitric and acetic acid attacks. The BRHA, collected from an electrical generating power plant that uses rice husk as fuel, was ground using a grinding machine. The compressive strength loss, weight loss, and expansion of mortars under nitric and acetic acid attack were investigated. The test results of BRHA properties in accordance with the ASTM C 618 standard found that the optimal grinding time was 4 h as this achieved a Blaine fineness of 5370 cm(2)/g. For parametric study, BRHA were used as a Portland cement Type 1 replacement at the levels of 0%, 10%, 20%, 30%, 40%, and 50% by weight of binder. The water-to-binder ratios were 0.55, 0.60, and 0.65. From test results, when the percentage replacements of BRHA in cement increased, it was observed that the strength loss and weight loss of mortars containing BRHA under acetic acid attack were higher than those of the mortars against nitric acid attack. It was found that, of the various BHRA mortars, the strength loss and weight loss due to nitric and acetic acid attacks were the lowest in the mortar with 10% BRHA replacement. For 10%, 20% and 30% BRHA replacements, the rate of expansion of the BRHA mortar decreased when compared with the control mortar. For the mortars with other percentage replacements of BRHA, the rate of expansion increased. Furthermore, the effective water-to-binder ratios of control and BRHA mortars were the primary factor for determining the durability of mortar mixed with BRHA. PMID:24412985

Chatveera, B; Lertwattanaruk, P

2014-01-15

405

Utilization from Cement Kiln Dust in Removal of Acid Dyes  

Directory of Open Access Journals (Sweden)

Full Text Available Problem statement: The growth of industries and day to day changes in human activities has resulted in an increase in the volume and complexity of wastewater to the environment. Textile industry is one of the most water consumers industries of Egypt, thus discharges large amounts of wastewater effluents during processing, especially, in the coloring and washing steps. Cement kiln dust is a solid waste in cement manufacturing. Approximately 2.5-3.0 (6-9% million tons of cement kiln dust is produced annually in Egypt and that cause significant environmental problems. Approach: This study aims to investigate removal of some acid dyes from aqueous solution using cement kiln dust and monitoring the dye in colored cement kiln dust. Solution with 0.4 g L-1 concentration was treated with cement kiln dust until the color of dye disappears. The colored cement kiln residue was separate by filtration and dried. The concentration of dye was measured before and after treatment by UV-Vis spectroscopy as well as after washing of colored residue. Also, the colored residue was investigated with, XRD, IR and DSC techniques as well as the loss on ignition at 450°C. Results: The results found that the cement kiln dust has the power to remove all existing acid dyes and the residue has the same color of dye. When colored residue was washed with water, there was no back diffusion of dye in to water. This may be mainly due to chemical reaction that took place between cement kiln dust and dye. Thus analysis such as IR, XRD and DSC are in agreement with these results. Conclusion: CKD is efficient in the processes of dye removal from aqueous solutions. The interaction between acid dye and CKD is fast (just minutes. So, we suggest using spent CKD for dye removal of waste water.

Mohamed E.S.I. Saraya

2012-01-01

406

Recovery of acetic acid from pre-hydrolysis liquor of hardwood kraft-based dissolving pulp production process by reactive extraction with triisooctylamine.  

Science.gov (United States)

Acetic acid was one of the main compositions of the pre-hydrolysis liquor (PHL), which was recovered by reactive extraction with triisooctylamine (TIOA) diluted with decanol. Dilution of TIOA played an important role in extracting acetic acid from the PHL. The recovery of acetic acid from the PHL by TIOA was increased from 10.34% to 66.60% with the dilution of TIOA to 20% by decanol at the HAc to TIOA molar ratio of 1, consequently, the equilibrium distribution coefficient KD increased. The effects of time, temperature and pH on the extraction process were also studied. The extraction process was very fast. The acetic acid extraction decreased from 65.13% to 57.34% with the rise of temperature to 50°C from 20°C. A higher pH increased the dissociation of acetic acid, as a result, decreased acetic acid extraction. The hemicelluloses in the PHL were unaffected on the extraction process of acetic acid. PMID:23619137

Yang, G; Jahan, M Sarwar; Ahsan, Laboni; Zheng, Linqiang; Ni, Yonghao

2013-06-01

407

Online stable carbon isotope ratio measurement in formic acid, acetic acid, methanol and ethanol in water by high performance liquid chromatography-isotope ratio mass spectrometry  

International Nuclear Information System (INIS)

A suitable analysis condition was determined for high performance liquid chromatography-isotope ratio mass spectrometry (HPLC-IRMS) while making sequential measurements of stable carbon isotope ratios of ?13C in formic acid, acetic acid, methanol and ethanol dissolved in water. For this online column separation method, organic reagents are not applicable due to carbon contamination; thus, water and KH2PO4 at low concentrations were tested as mobile phase in combination with a HyPURITY AQUASTARTM column. Formic acid, acetic acid, methanol and ethanol were separated when 2 mM KH2PO4 aqueous solution was used. Under the determined analysis condition for HPLC-IRMS, carbon concentrations could be measured quantitatively as well as carbon isotope ratio when carbon concentration was higher than 0.4 mM L for each chemical

408

Comparative photocatalytic study of two selected pesticide derivatives, indole-3-acetic acid and indole-3-butyric acid in aqueous suspensions of titanium dioxide  

International Nuclear Information System (INIS)

Heterogeneous photocatalysed degradation of two selected pesticide derivatives such as indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) has been investigated in aqueous suspensions of titanium dioxide by monitoring the change in substrate concentration employing UV spectroscopic analysis technique and depletion in total organic carbon (TOC) content as a function of irradiation time. The degradation kinetics was studied under different conditions such as pH, types of TiO2, substrate and catalyst concentration, and in the presence of electron acceptor such as hydrogen peroxide (H2O2) besides molecular oxygen. The degradation rates were found to be strongly influenced by all the above parameters. The photocatalyst Degussa P25 showed comparatively highest photocatalytics. The pesticide derivative, indole-3-acetic acid was found to degrade slightly faster than indole-3-butyric acid

409

Methylene blue immobilized on cellulose acetate with titanium dioxide: an application as sensor for ascorbic acid  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Neste trabalho, o corante azul de metileno foi imobilizado na superfície do acetato de celulose modificado com dióxido de titânio produzindo um material híbrido sólido denominado de CA-TiO2MB. O experimento produziu uma quantidade de 1,8 mmol g-1 de TiO2 incorporado no acetato de celulose e uma quan [...] tidade de 0,170 ± 0,005 mmol g-1 de azul de metileno adsorvido na superfície do CA-TiO2. Um eletrodo de pasta de carbono desse material foi usado para estudar a oxidação eletrocatalítica do ácido ascórbico pelas técnicas de voltametria cíclica e cronoamperometria. O pH da solução não afetou o potencial de pico de anódico nem a corrente de pico anódico ao variar de 3,0 a 7,0. A oxidação do analito ocorreu em 75 mV versus ECS em solução de KCl 1,0 mol L-1 e pH 7,0. A intensidade da corrente de pico anódico variou com a concentração de ácido ascórbico na faixa de 5,0 × 10-4 mol L-1 to 4,5 × 10-3 mol L-1, sendo observada uma correlação linear com um limite de detecção de 15 µmol L-1, limite de quantificação de 50 µmol L-1 e uma sensibilidade de 7,1 µA L mol-1. A resposta do eletrodo foi muito rápida, com um tempo decorrido de 1,0 s, mostrando potencial para ser utilizado como um sensor eletroquímico para a determinação de ácido ascórbico em produtos comerciais. Abstract in english In this work, methylene blue dye was immobilized on the surface of cellulose acetate modified with titanium dioxide, producing a solid hybrid material designated as CA-TiO2MB. The experiment yielded an amount of 1.8 mmol g-1 of TiO2 incorporated in the cellulose acetate and an amount of 0.170 ± 0.00 [...] 5 mmol g-1 of methylene blue adsorbed onto CA-TiO2 surface. A carbon paste electrode of this material was used to study the electrocatalytic oxidation of ascorbic acid by cyclic voltammetric and chronoamperometric techniques. The pH of the solution had no effect on the anodic peak potential and anodic peak current when ranging from 3.0 to 7.0. The oxidation of the analyte occurred at 75 mV versus SCE in 1.0 mol L-1 KCl solution and pH 7.0. The intensity of the anodic peak current varied with the concentration of ascorbic acid from 5.0 × 10-4 mol L-1 to 4.5 × 10-3 mol L-1 and a linear correlation was observed, with a detection limit of 15 µmol L-1, quantification limit of 50 µmol L-1 and a sensitivity of 7.1 µA L mol-1. The electrode response was very fast, with an elapsed time of about 1.0 s, showing the potentiality to be utilized as an electrochemical sensor for determination of ascorbic acid in commercial samples.

Andrea A., Hoffmann; Silvio L. P., Dias; Jordana R., Rodrigues; Flavio A., Pavan; Edilson V., Benvenutti; Eder C., Lima.

410

Kinetic Analysis of Strains of Lactic Acid Bacteria and Acetic Acid Bacteria in Cocoa Pulp Simulation Media toward Development of a Starter Culture for Cocoa Bean Fermentation ?  

OpenAIRE

The composition of cocoa pulp simulation media (PSM) was optimized with species-specific strains of lactic acid bacteria (PSM-LAB) and acetic acid bacteria (PSM-AAB). Also, laboratory fermentations were carried out in PSM to investigate growth and metabolite production of strains of Lactobacillus plantarum and Lactobacillus fermentum and of Acetobacter pasteurianus isolated from Ghanaian cocoa bean heap fermentations, in view of the development of a defined starter culture. In a first step, a...

Lefeber, Timothy; Janssens, Maarten; Camu, Nicholas; Vuyst, Luc

2010-01-01

411

Rapid analysis of formic acid, acetic acid, and furfural in pretreated wheat straw hydrolysates and ethanol in a bioethanol fermentation using atmospheric pressure chemical ionisation mass spectrometry  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Atmospheric pressure chemical ionisation mass spectrometry (APCI-MS offers advantages as a rapid analytical technique for the quantification of three biomass degradation products (acetic acid, formic acid and furfural within pretreated wheat straw hydrolysates and the analysis of ethanol during fermentation. The data we obtained using APCI-MS correlated significantly with high-performance liquid chromatography analysis whilst offering the analyst minimal sample preparation and faster sample throughput.