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PubMed2006

Photocatalytic activity of the calcined H-titanate nanowires for photocatalytic oxidation of acetone in air.

Hydrogen titanate (H-titanate) nanowires were prepared via a hydrothermal reaction of TiO2 powders (P25) in KOH solutions and then calcined at various temperatures. The phase structure, crystallite size, morphology, specific surface area, and pore structures of the calcined H-titanate nanowires at various temperatures were characterized with field emission scanning electron microscope, X-ray diffraction, transmission electron microscopy and nitrogen adsorption-desorption isotherms, and their photocatalytic activities were evaluated by photocatalytic oxidation of acetone in air. With increasing calcination temperature, the specific surface area and porosity of the calcined samples steadily decreased. At a calcination temperature range of 400-600 degrees C, the calcined H-titanate nanowires showed higher photocatalytic activity than P25 powders for photocatalytic oxidation of acetone. Especially, at 500 degrees C, the calcined H-titanate nanowires showed the highest photocatalytic activity, which exceeded that of P25 by a factor of about 1.8 times. This can be attributed to the synergetic effect of larger specific surface area, higher pore volume and the presence of brookite TiO2. With further increase in the calcination temperature (700-900 degrees C), the photocatalytic activity of the samples decreased obviously owing to the growth of TiO2 crystallites.

Acetone↗
PubMed2005

Improved cellular adhesion to acetone plasma modified polystyrene surfaces.

The plasma polymerization of acetone has been used to modify polystyrene substrates for the controlled growth of human fibroblast cells. The surface modified polystyrene was studied by X-ray photoelectron spectroscopy, water contact angle and atomic force microscopy. This showed the surface oxygen levels and wettability to increase rapidly with exposure to the acetone plasma. High-resolution XPS allowed the determination of the relative amounts of surface hydroxyl, carbonyl and carboxyl groups. This showed that there was little incorporation of carboxyl groups in the deposited films. AFM measurements revealed the films to be conformal with a surface roughness equivalent to that of the underlying polystyrene substrate with film growth rates of approximately 0.5 nm min(-1). High edge-definition patterns were produced with a simple masking procedure and allowed the confinement of cells to selected areas of the substrate. These chemically patterned surfaces allowed the study of cells confined to particular regions of the substrate as a function of incubation time.

Acetone↗
PubMed2005

Hypoglycaemic and antidiabetic activity of acetonic extract of Vernonia colorata leaves in normoglycaemic and alloxan-induced diabetic rats.

The aqueous extract of Vernonia colorata (Willd.) Drake (Composeae) leaves is used by African traditional medicine practitioners as a remedy for the treatment of diabetes. Our previous studies have shown the hypoglycaemic activity of the aqueous extract of Vernonia colorata leaves (300 mg/kg, per os) in normoglycaemic rats. The aim of the present study was to investigate the hypoglycaemic and antidiabetic activity of acetonic and hexanic extracts of the leaves of Vernonia colorata in order to further discriminate the type of extract which provides a better antidiabetic activity. Experiments were performed in normoglycaemic and alloxan-induced diabetic rats. The acetonic extract of the leaves of Vernonia colorata (AELVC) (100 mg/kg, per os) induced a significant decrease of blood glucose in normoglycaemic rats. The glycaemia varied from 4.72+/-0.11 to 3.72+/-0.22 mmol/l (p<0.05, n=5) 3 h after AELVC administration per os. In contrast, the hexanic extract of the leaves of Vernonia colorata (HELVC) increased significantly the glycaemia in normoglycaemic rats. Like glibenclamide, AELVC has an antihyperglycaemic effect in oral glucose tolerance test (OGTT) and alloxan-induced diabetic rats. These results have shown that: (i) AELVC and HELVC have an opposite effect on basal blood glucose in normoglycaemic rats, suggesting that the mechanisms of action of both above-mentioned extracts are different; (ii) AELVC has also an antidiabetic activity in hyperglycaemic rat models.

Acetone↗
PubMed2006

Fluorescence quenching of 3-methyl 7-hydroxyl Coumarin in presence of acetone.

Fluorescence quenching of 3-methyl 7-hydroxyl Coumarin in prescence of the acetone is reported here. It was found that the quenching observed was of dynamic nature. It is also observed that quenching of the fluorescence of the indicator had a full reversiblity. As it has a full reversiblity, a novel optical sensor for acetone can be constructed on this quenching.

Acetone↗
PubMed1990

Time-course of alterations of bladder function following acetone-induced cystitis.

Although chemical cystitis is known clinically to cause decreased bladder function, there are few experimental studies on the progression of, and recovery from chemical cystitis. Mature male rabbits underwent intravesical instillation of 50% acetone solution through a urethral catheter. Micturition profiles showed a marked decrease of the mean and maximal micturition volume and an increase in number of micturitions as early as one day after treatment. The micturition profile gradually normalized between four and eight weeks after instillation. In vivo cystometry showed a very small bladder capacity and low compliance during the first week following instillation, and gradually recovered to control levels by four weeks. Functional studies using the in vitro whole bladder model showed a significant decrease in the ability of the bladder to generate pressure and to empty at three days after instillation. These parameters recovered partially by two weeks, and completely by four weeks. Chemical cystitis induced by intravesical acetone instillation resulted in a severe decrease in the bladder function, i.e. contracted bladder with low compliance and poor ability to generate pressure and empty. However, these changes were reversible within the two month period of study.

Acetone↗
PubMed1985

Acetone-treated pertussis vaccine--a potent and safer new pertussis vaccine.

A vaccine was prepared from the growth of Bordetella pertussis by repeated treatment with acetone. The vaccine has been designated as acetone-treated pertussis vaccine (ATPV). A total of ten batches of ATPV were prepared, five each from B. pertussis strains 134 and 509. These strains are routinely employed at this Institute for the production of conventional whole-cell pertussis vaccine (WCPV) for blending in diphtheria-pertussis-tetanus vaccine. The mouse protective and histamine sensitizing activities of ATPV and WCPV were compared. The ATPV showed 1.5- to 2-fold higher potency than the WCPV. The histamine sensitizing activity of ATPV was much reduced compared with that of the WCPV. No appreciable difference was observed in the results of a mouse weight-gain tests between the ATPV and WCPV. The details of the preparation of ATPV have been described. Because of higher potency and reduced histamine sensitizing activity, the ATPV may prove more acceptable in immunization programmes against pertussis, even in countries where WCPV is unpopular due to its suspected reactogenicity.

Acetone↗
PubMed1997

The overwet phenomenon in two-component acetone-based primers containing aryl amine and carboxylic acid monomers.

OBJECTIVES: The overwet phenomenon was first reported when a moist bonding technique was used with an earlier commercial version of All-Bond 2 (Bisco) that contained BPDM in primer B. This study investigated whether ultrastructural features of the overwet phenomenon could also be detected in other commercially available two-component acetone-based primers containing BPDM, PMDM and PMGDM, as well as an experimental two-component primer containing DSDM. METHODS: Thirty 1 mm dentin discs prepared from third molars were each conditioned with 10% H3PO4 for 20 s and rinsed for 20 s. They were randomly divided into 5 groups: Group I (Bond-It, Jeneric/Pentron:PMGDM); Group II (Wet Bond, Chameleon Dental Products:PMGDM); Group III (Tenure S, Den-Mat:PMDM); Group IV (present commercial version of All-Bond 2, Bisco:BPDM) and Group V (Experimental two-component primer system containing DSDM in primer B). Following a moist bonding technique using the respective system, discs from each group were further bonded together to form three disc pairs using a chemical-cured resin. Bonded disc pairs were demineralized in EDTA and processed for TEM examination. For this ultramicroscopical study, results such as the features of the overwet phenomenon were analyzed by visual inspection of the specimens in each group (n = 12). RESULTS: Isolated blister-like spaces of variable dimensions were observed within the primer layer in all groups and possessed the following characteristics: 1) a layer of resin-impregnated dentin was always present along the base of the primary blister; 2) surface primer globules, sometimes containing secondary blisters, were identified within these primary blisters; 3) dentinal tubules within the blister-like spaces were not completely sealed; 4) primer globules were circumscribed by a halo of fine kinked strands of material. SIGNIFICANCE: Although the technique of moist bonding is based on valid biological principles, incorporation of resin monomers that are immiscible with water rendered the application of current two-component, acetone-based primers very technique-sensitive in terms of tubular seal, when used on moist, acid-conditioned dentin. Further studies should be directed at elimination of this type of oil-in-water (O/W) "macroemulsion" formation through optimal micellar solubilization of these resin monomers in water.

Acetone↗
PubMed1998

Cold acetone fixation and methacrylate embedding. A suitable method for routine processing of bone marrow biopsies.

Here we report that acetone fixation at -18 degrees C with subsequent embedding in methyl-/butylmethacrylate is a reliable method for the routine processing of bone marrow biopsies. This method allows good conventional histological visualization of morphological details, which is comparable with other fixation procedures. The essential advantage of this method is that a wide range of monoclonal antibodies and polyclonal antisera can be used for immunohistochemical investigations for diagnostic and scientific purposes. The addition of 5% polyethylene glycol 400 to the acetone minimizes freeze-related artefacts. The immunohistochemical demonstration of a number of antigens is mostly affected by the medium used for slide preparation and to a lesser extent by the concentration of benzoylperoxide used for polymerization. Performing polymerization at 4 degrees C and using N, N-dimethyl-p-toluidine as accelerator allows the concentration of benzoylperoxide to be reduced to 0.2 g% (8.3 mmol). Under these conditions the methacrylate embedding procedure has only minimal effects on the quality of immuno- and enzyme histochemistry. Additionally, the simplified method for removing the polymerization inhibitor from the methacrylate components and the shortened impregnation step are further advantages of the embedding method described here.

Acetone↗
PubMed1997

Laser-induced modification of DNA and Poly[A,G] at guanine moiety using acetone as photosensitizer.

The interactions of triplet acetone with polyadenylic acid (Poly[A]), polyguanylic acid (Poly[G]), polyadenylic-guanylic acid (Poly[A,G]) and single-stranded DNA (ssDNA) were investigated in neutral aqueous solution using KrF (248 nm) laser flash photolysis. The transient absorption spectra and kinetics of DNA and polynucleotides obtained under acetone sensitization demonstrated that the predominant transient species was guanine radical. These novel findings have offered time-resolved evidence for photochemical modification of DNA and Poly[A,G] at guanine moiety.

Acetone↗
PubMed2000

Derivatization of protonated peptides via gas phase ion-molecule reactions with acetone.

The protonated [M + H]+ ions of glycine, simple glycine containing peptides, and other simple di- and tripeptides react with acetone in the gas phase to yield [M + H + (CH3)2CO]+ adduct ion, some of which fragment via water loss to give [M + H + (CH3)2CO - H2O]+ Schiff's base adducts. Formation of the [M + H + (CH3)2CO]+ adduct ions is dependent on the difference in proton affinities between the peptide M and acetone, while formation of the [M + H + (CH3)2CO - H2O]+ Schiff's base adducts is dependent on the ability of the peptide to act as an intramolecular proton "shuttle." The structure and mechanisms for the formation of these Schiff's base adducts have been examined via the use of collision-induced dissociation tandem mass spectrometry (CID MS/MS), isotopic labeling [using (CD3)2CO] and by comparison with the reactions of Schiff's base adducts formed in solution. CID MS/MS of these adducts yield primarily N-terminally directed a- and b-type "sequence" ions. Potential structures of the b1 ion, not usually observed in the product ion spectra of protonated peptide ions, were examined using ab initio calculations. A cyclic 5 membered pyrrolinone, formed by a neighboring group participation reaction from an enamine precursor, was predicted to be the primary product.

Acetone↗
PubMed2000

Absolute band intensities in the nu19/nu23 (530 cm(-1)) and nu7 (777 cm(-1)) bands of acetone ((CH3)2CO) from 232 to 295 K.

Absolute band intensities of acetone ((CH3)2CO) in the nu19/nu23 and nu7 band systems near 530 and 777 cm(-1), respectively, were measured at temperatures of 232, 262 and 295 K, using a Fourier transform infrared (FTIR) spectrometer. No evident temperature dependence for the band intensities was observed. The dipole moments and the fundamental band intensities were derived in the harmonic oscillator approximation. The results are useful for the spectroscopic retrieval of acetone concentrations in the upper atmosphere.

Acetone↗
PubMed1995

Removal of superglue from the external ear using acetone: case report and literature review.

The ability of superglue preparations (cyanoacrylate) to bond instantly to skin as well as inanimate objects presents a special problem when instilled into the external ear canal. We present two cases of patients who had it successfully removed under the microscope with the help of acetone BP to debond it from the skin, without any damage to the meatus or the tympanic membrane. The third patient had the superglue removed without the help of acetone but sustained damage to the tympanic membrane. A literature review of similar cases is included.

Acetone↗
PubMed1989

Simultaneous determination of bromide and iodide as acetone derivatives by gas chromatography and electron capture detection in natural waters and biological fluids.

Oxidation of bromide and iodide ions in acidic solutions in the presence of acetone forms the corresponding acetone derivatives. Iodate was reduced with thiosulfate prior to the determination. After extraction with benzene the bromo- and iodoacetone were measured by gas chromatography using electron capture detection. The bromide and iodide contents of rainwater, drinking water, river water, seawater, oil brine, common salt, cow milk, and human blood serum were determined. The relative standard deviations for bromide at 10(-7) M and for iodide at 10(-8) M concentration were 1.9% and 3.0%, respectively, using a 10-mL sample for the determination without preconcentration.

Acetone↗
PubMed2005

Activated carbon load equalization of discontinuously generated acetone and toluene mixtures treated by biofiltration.

Studies were conducted to evaluate use of granular activated carbon (GAC) as a passively operated load-equalization mechanism for biofilters treating gas streams with dynamically varying (intermittent) pollutant loading. In the initial stage of research, abiotic fixed-bed sorption experiments and numerical modeling were conducted to assess the degree of load-equalization achieved by GAC columns for air flows containing intermittent loading of acetone and toluene present as single-component contaminants and as a mixture. In the subsequent stage of research, an integrated system consisting of a GAC column in series before a biofilter was used to treat a gas stream containing a mixture of acetone and toluene at influent concentrations of 430 ppm(v) and 100 ppm(v) respectively. To simulate loading conditions expected from an industrial process with intermittent operation, contaminated air was supplied 8 h/day and uncontaminated air was supplied 16 h/day. The system was operated with different empty bed contact times, as low as 2.5 s for the GAC column and 14.5 s for the biofilter. Performance of an additional, conventionally operated biofilter (i.e., without GAC load equalization system) was used as a basis of comparison. Data are presented which clearly demonstrate that passively operated GAC load-dampening systems installed in series before biofilters can lead to more uniform loading as a function of time and thereby improve biofilter treatment performance. Results also demonstrate that, because of competitive sorption, the degree of load equalization achieved for different constituents in multi-contaminant gas streams can vary markedly. A pore and surface diffusion model (PSDM) was able to accurately predict the degree of load-dampening achieved by GAC columns for single and multicomponent waste gases.

Acetone↗
PubMed2004

Charge development in the transition state for decarboxylations in water: spontaneous and acetone-catalyzed decarboxylation of aminomalonate.

A covalent imminium adduct, formed by condensation of aminomalonate with acetone, undergoes decarboxylation (k = 0.03 s-1 at 25 degrees C) in water 30 000 times more rapidly than does aminomalonate in the absence of acetone. A Brønsted plot of the observed rates of decarboxylation of these and other ionized carboxylic acids, as a function of the pKC-H values of the carbon acids generated by their decarboxylation, exhibits a betalg value of 0.7, indicating that the structures of the transition states for decarboxylation of the carboxylate forms of these acids approaches the structures of the carbanions generated by their decarboxylation. On the basis of an estimated pKC-H value for benzene in water ( approximately 43), extrapolation of that Brønsted plot leads to the prediction that benzoate decarboxylation should proceed at detectable rates in water at temperatures below the critical point. That prediction was confirmed experimentally. Using this same relationship, and extrapolating to the observed rate constant for enzymatic decarboxylation of orotidine 5'-monophosphate, we estimate that the "effective" pKa value of the 6-CH group of uridine 5'-monophosphate, the product of decarboxylation, is 9.5 at the active site of yeast OMP decarboxylase.

Acetone↗
PubMed2004

Chemical constituents, antifungal and antioxidative effects of ajwain essential oil and its acetone extract.

GC and GC-MS analysis of ajwain essential oil showed the presence of 26 identified components which account for 96.3% of the total amount. Thymol (39.1%) was found as a major component along with p-cymene (30.8%), gamma-terpinene (23.2%), beta-pinene (1.7%), terpinene-4-ol (0.8%) whereas acetone extract of ajwain showed the presence of 18 identified components which account for 68.8% of the total amount. The major component was thymol (39.1%) followed by oleic acid (10.4%), linoleic acid (9.6%), gamma-terpinene (2.6%), p-cymene (1.6%), palmitic acid (1.6%), and xylene (0.1%). Moreover, the oil exhibited a broad spectrum of fungitoxic behavior against all tested fungi such as Aspergillus niger, Aspergillus flavus, Aspergillus oryzae, Aspergillus ochraceus, Fusarium monoliforme, Fusarium graminearum, Pencillium citrium, Penicillium viridicatum, Pencillium madriti, and Curvularia lunata as absolute mycelial zone inhibition was obtained at a 6-microL dose of the oil. However, the acetone extract showed better antioxidative activity for linseed oil as compared with synthetic antioxidants such as butylated hydroxyl toluene and butylated hydroxyl anisole.

Acetone↗
PubMed2000

Pervaporative stripping of acetone, butanol and ethanol to improve ABE fermentation.

Acetone-butanol-ethanol fermentation by anaerobic bacterium C. acetobutylicum is a potential source for feedstock chemicals. The problem of product induced inhibition makes this fermentation economically infeasible. Pervaporation is studied as an effective separation technique to remove the toxic inhibitory products. Various membranes like Styrene Butadiene Rubber (SBR), Ethylene Propylene Diene Rubber (EPDM), plain Poly Dimethyl Siloxane (PDMS) and silicalite filled PDMS were studied for the removal of acetone, butanol and ethanol, from binary aqueous mixtures and from a quaternary mixture. It was found that the overall performance of PDMS filled with 15% w/w of silicalite was the best for removal of butanol in binary mixture study. SBR performance was best for the quaternary mixture studied.

Acetone↗
PubMed1997

The influence of 2-propanol and acetone on oviposition rate and oviposition site preference for acetic acid and ethanol of Drosophila melanogaster.

Drosophila melanogaster strains, homozygous for the alcohol dehydrogenase alleles AdhF, AdhS, and Adhn4 respectively, were tested for oviposition site preference with a Multiple Choice Device consisting of 18 patches per choice disk. Equal numbers of patches with ethanol-, acetic acid-, and water-supplemented medium were offered simultaneously. Patches with acetic acid-supplemented medium were chosen predominantly as oviposition sites. Pretreatment of flies with increasing concentrations of 2-propanol to inhibit alcohol dehydrogenase (ADH) activity resulted not only in a decreasing choice of acetic acid patches, but also in the laying of a decreasing number of eggs. Adh-null mutant flies showed a similar change in behavior pattern after 2-propanol treatment. Therefore it was concluded that ADH activity is not involved primarily in oviposition site preference behavior. A complicating factor is acetone, the oxidation product of 2-propanol, which had an even larger impact on egg production. However, differences in ADH allozymes with respect to biochemical oxidation capacity of secondary alcohols will not necessarily lead to differences between the Adh genotypes in oviposition rates or apparent changes in preferences, due to additional biochemical differences in inhibition rates by acetone of the various allozymes and other enzyme systems.

1-Propanol↗