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PubMed2006

Shear bond strength of acetone-based one-bottle adhesive systems.

The aim of this study was to assess the shear bond strength of four acetone-based one-bottle adhesive systems to enamel and dentin, and compare to that of an ethanol-based system used as control. Fifty human molars were bisected mesiodistally and the buccal and lingual surfaces were embedded in acrylic resin using PVC cylinders. The buccal surfaces were ground to obtain flat dentin surfaces, while the lingual surfaces were ground to obtain flat enamel surfaces. All specimens were polished up to 600-grit sandpapers and randomly assigned to 5 groups (n=20; 10 dentin specimens and 10 enamel specimens), according to the adhesive system used: One-Step (Bisco); Gluma One Bond (Heraeus Kulzer); Solobond M (Voco); TenureQuik w/F (Den-Mat) and OptiBond Solo Plus (Kerr) (control). Each adhesive system was applied according to the manufacturers' instructions. The respective proprietary hybrid composite was applied in a gelatin capsule (d=4.3 mm) and light-cured for 40 s. The specimens were tested in shear strength with an Instron machine at a crosshead speed of 5 mm/min. Bond strengths means were analyzed statistically by one-way ANOVA and Duncan's post-hoc (p< or =0.05). Shear bond strength means (MPa) (+/-SD) to enamel and dentin were: Enamel: One-Step=11.3(+/-4.9); Gluma One Bond=16.3(+/-10.1); Solobond M=18.9(+/-4.5); TenureQuik w/F=18.7(+/-4.5) and OptiBond Solo Plus=16.4(+/-3.9); Dentin: One-Step=6.4(+/-2.8); Gluma One Bond=3.0(+/-3.4); Solobond M=10.6(+/-4.9); TenureQuik w/F=7.8(+/-3.9) and OptiBond Solo Plus=15.1(+/-8.9). In enamel, the adhesive systems had statistically similar bond strengths to each other (p>0.05). However, the ethanol-based system (OptiBond Solo Plus) showed significantly higher bond strength to dentin than the acetone-based systems (p< or =0.0001). In conclusion, the solvent type (acetone or ethanol) had no influence on enamel bond strength, but had great influence on dentin bonding, which should be taken into account when choosing the adhesive system.

Acetone↗
PubMed1991

Metabolism of inhaled styrene in acetone-, phenobarbital- and 3-methylcholanthrene-pretreated rats: stimulation and stereochemical effects by induction of cytochromes P450IIE1, P450IIB and P450IA.

1. The effect of various cytochrome P-450 inducers, namely acetone, phenobarbital (PB) and 3-methylcholanthrene (MC), on the pharmacokinetics of styrene metabolism was studied. 2. Styrene metabolism in vivo was studied measuring phenylglyoxylic acid (PGA), the enantiomers of mandelic acid (MA), and total thioethers excreted in the urine during a 24 h period of airborne exposure to styrene at 500 cm3/m3 (2100 mg/m3). In acetone-pretreated rats, PGA and MA and thioether formation were elevated 30-50%. The R/S ratio of MA enantiomers was about two in all styrene-exposed groups except PB-pretreated rats, which showed a ratio of four. 3. Styrene metabolism in liver microsomes measured in vitro was increased by styrene 140%, acetone plus styrene by 190%, methylcholanthrene plus styrene by 180% and phenobarbital plus styrene by 250%. 4. N-Nitrosodimethylamine demethylation (NDMAD) and 7-pentoxyresorufin dealkylation (PROD) in liver microsomes were enhanced 100-150% by styrene inhalation. The metabolism of 7-ethoxyresorufin was not significantly enhanced. 5. Monoclonal antibodies to P-450 IA1, IA2, IIB1 and IIE1 were utilized to identify cytochrome P-450s by Western blot analysis. These studies showed clearly that styrene inhalation induced principally cytochrome P450IE1, whereas styrene given by gavage at a high narcotic dosage induced both P450IIE1 (NDMAD, 60%) and P450IIB (PROD, 3000%). 6. Our conclusions are that styrene metabolism in vivo in both autoinduced and induced by other foreign compounds, that cytochrome P450IIE1 induction has a major impact on styrene metabolism and that P450IIB1 induction yields an altered MA metabolite enantiomer ratio.

Acetone↗
PubMed1993

Sonochemistry of acetone and acetonitrile in aqueous solutions. A spin trapping study.

The 50 kHz sonolysis of argon-saturated water-acetone and water-acetonitrile mixtures was studied by EPR and spin trapping with 3,5-dibromo-4-nitrosobenzenesulfonate over a wide range of solvent composition. For both systems a single maximum was observed for the spin adduct yield of methyl radicals and of the radicals formed by H-abstraction from acetone and acetonitrile. These results combined with previous studies of water-methanol and water-ethanol mixtures indicate that the greater the vapor pressure of the volatile organic component, the lower the concentration of organic solute at which the maximum radical yield occurs. Methyl radicals from acetone are formed by C-C bond scission in the collapsing argon bubbles. For acetonitrile, C-H bond scission at high temperature is followed by H-addition to the triple bond and the decomposition of this intermediate radical to form methyl radicals. Since Anbar has shown (Science 161, 1343, 1961) that sonoluminescence and acoustic cavitation occur during the impact of liquid water on water with linear velocities similar to those of collapsing ocean waves, the sonochemistry of nitriles is of interest to chemical evolution studies.

Acetone↗
PubMed2001

Determination of acetone in cow milk by Fourier transform infrared spectroscopy for the detection of subclinical ketosis.

Fourier transform infrared analysis (FTIR) was used in combination with partial least squares regression (PLS) to predict the concentration of acetone in milk. FTIR spectra were compared with results of a gas-chromatographic head space method. Principal component analysis of whole spectra (3000 to 1000 cm(-1)) suggested to reduce the spectrum of analysis for acetone to 1450 to 1200 cm(-1). A second derivative was applied to the spectra to remove baseline effects and further enhance the spectral features. Full cross-validation was used to compare the reference with predicted acetone concentrations of samples not included in model development. PLS applied to the full spectral range resulted in a complex 19-factor model with a cross-validation error of 0.22 mM. After reducing the spectrum and taking the second derivative, we obtained a model with seven factors that yielded a cross-validation error of 0.21 mM. This compares favorably with a previously reported model with 20 factors and an error of 0.25 mM. Using PLS predictions to identify cows with subclinical ketosis resulted in 95 to 100% sensitivity and 96 to 100% specificity when the threshold for subclinical ketosis was 0.4 to 1.0 mM. The corresponding positive predictive values were > or = 76% and the negative predictive values > 98% throughout an assumed range of subclinical ketosis prevalence of 10 to 30%.

Acetone↗
PubMedDate not supplied

[Effects of a plant preparation Korrda-K on metabolic reactions in the liver of rats exposed to acetone].

The paper deals with the study of the preventive effect of the plant drug Korrda-K on lipid and carbohydrate metabolism in the liver of the rat exposed to acetone inhalation. The agent was found to have hepatic and membranous protective effects. On exposure to acetone, Korrda-K promotes the normalization of blood glucose levels and other biochemical parameters. The magnitude of changes in the composition of lipids and fatty acids suggests that the preventive use of the agent favours the preservation of the membrane structure of hepatocytes changed by acetone.

Acetone↗
PubMed1975

[The effect of various solvents (benzene, toluene, acetone) used with carcinogens on the collagen content of the mouse dorsal skin].

Benzene, toluene and acetone--frequently used as solvents of skin carcinogens--have different effects on the skin collagen of mice: Benzene and toluene lower the collagen content significantly whereas acetone does not. Methylcholanthrene solved in acetone causes a slower collagen decrease and a longer latency period of tumor development as can be observed, when solved in benzene or toluene. This leads to the conclusion, that benzene and toluene have a cocarcinogenic potency.

Acetone↗
PubMedDate not supplied

[The effect of the inhalation of ethanol and acetone on the indices of the antioxidant protection system and on lipid peroxidation in the brain tissue and blood serum of rats].

Ethanol or acetone inhalation resulted in a reduction in motor activity in rats, affecting largely their explorative behavior. The biochemical parameters of free-radical processes (catalyse and SOD activities, LPO levels) remained unchanged in the inhaling animals. Ethanol or acetone inhalation caused a significant decrease in blood catalyse activity and serum LPO levels. The acetone- and ethanol-induced changes in the activity of ceruloplasmin were heterodirectional. It can be concluded that it is useful to study the biochemical parameters of serum free-radical processes and to employ the findings in the therapy of inhalation toxicomanias.

Acetone↗
PubMed1992

[Isopropanol and acetone level in serum after preoperative surface disinfection with antiseptics containing isopropanol].

After preoperative skin disinfection in pediatric surgery, serum levels of isopropanol up to 12.2 mg/l (MW 5.0 mg/l +/- 3.37, n = 26) were found. They result from a rapid and prolonged but uncharacteristic percutaneous resorption of the isopropanol-containing disinfectant. In about 50% of the cases, serum levels of acetone showed an increase up to 82 mg/l already before skin disinfection, presumably caused by preoperative starvation. After skin disinfection, raised acetone levels were found in 19 of 26 cases. As increased isopropanol and acetone levels are discussed as alcoholism markers, a falsification of congener analysis after skin disinfection, e.g. in cases of adult victims of accidents, has to be taken into consideration. Endogenous serum levels of methanol (0.87 mg/l +/- 0.49), ethanol (0.32 mg/l +/- 0.09), acetaldehyde (0.31 mg/l +/- 0.10) and others remained unaffected. Some uncharacteristic elevations of propanol-1 levels are caused by contaminated rubber caps.

1-Propanol↗
PubMedDate not supplied

The effect of acetone on the viability of chicken anemia agent.

To study the effect of acetone on the viability of CAA, a sample of CAA with a known titer was treated with 90% acetone for 24 hours at room temperature. The remaining viable CAA was quantitated by titrating the treated preparation in MDCC-MSB1 cell culture. Results indicated that CAA is very resistant to inactivation by acetone.

Acetone↗
PubMed2003

Topical toxicity of two acetonic fractions of Trichilia havanensis Jacq. and four insecticides to larvae and adults of Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae).

The toxicity of botanical origin compounds such as two acetonic fractions of the seed kernels of the Meliacea Trichilia havanensis Jacq with insecticide properties (azadirone (F12) and the mixture F18 [1,7+3,7-di-O-acethylhavanensin (4:1)], three insecticides commercially available (imidacloprid, natural pyrethrins+PBO, triflumuron) and phloxine B, were tested in the laboratory. Topical bioassays using third instar and newly emerged adults of the lacewing Chrysoperla carnea (Stephens) at the maximum field recommended rate in Spain for commercials and at 1,000 ppm of active ingredient for T. havanensis acetone fractions and phloxine-B, were carried out. Imidacloprid and triflumuron were very toxic to third instar larvae inhibiting adult emergence, being the rest of insecticides harmless. Fecundity and fertility were not affected by the non-toxic compounds. Concerning adults, only imidacloprid and natural pyrethrins killed them significantly 24 hours after treatment. Phloxine B, triflumuron and T. havanensis fractions were harmless and did not cause any effect on fecundity and fertility with the exception of triflumuron, which reduced considerably the egg hatch. It can be concluded that T. havanensis acetonic fractions and phloxine B were non-toxic to larvae and adults of C. carnea when treated topically, whereas triflumuron, natural pyrethrins and imidacloprid affected one or more of the evaluated parameters under our conditions.

Acetone↗
PubMedDate not supplied

[Effect of starvation and acetone on the enzyme systems of biotransformation and toxicity of xenobiotics--CYP2E1 substrates in rats].

In experiments on 205 rats it was fixed, that starvation during 2-3 days, as well as introduction of acetone (250 and 1000 mg/kg) considerably increases CYP2E1-dependent aniline and p-nitrophenol hydroxylase activity in the liver, kidneys, lungs and CYP3A dependent erythromycin N-demethylase activity, at the same time, suppress in a liver activity enzymes, dependent CYP2D, CYP1A2 and CYP2C as well as of activity UDP-glucuronosyl-transferase, sulfotransferase and glutathione-S-transferase. The starvation causes accumulation of KoA and increases activity of N-acetyltransferase in the liver. Starvation induces the change of enzymes activity and correlates with the intensifying of the processes of lipolysis, glycogenolysis, gluconeogenesis and, especially, ketogenesis which are appreciably initiated by introduction of acetone. The starvation and introduction of acetone increases metabolism of acetanilide and brombenzene, and, increasing the formation of toxic metabolites, raise its hepato-, nephro- and pulmotoxicity. The starvation attenuates elimination of indometacin from blood plasma, but intensifies conjugation of sulfadimidine with acetic acid.

Acetone↗
PubMedDate not supplied

[Experimental substantiation of the maximum permissible concentrations of acetone and acetaldehyde in regenerated drinking water].

The paper presents experimental data indicating maximum permissible concentrations of acetone and acetaldehyde in reclaimed potable water used for different periods of time--up to 1, 3 or 12 months. The recommended concentrations for reclaimed water used for a year are 14.0 mg/l and 0.2 mg/l for acetone and acetaldehyde, respectively. The recommended levels for reclaimed water used for 1--3 months are 39.6 mg/l and 0.2 mg/l for acetone and acetaldehyde, respectively.

Acetaldehyde↗
PubMed1986

Acidic acetone extract from pregnant sow ovaries is a rich source of substances affecting uterine contractility in vitro.

Acidic acetone extract of pregnant sow ovaries was subjected to Sephadex G-25 chromatography. The solution coming from column was analysed for UV absorption, molecular weight, and also for its biological effect on a myometrium strip in vitro. This biodetection system has made it possible continuously to determine the biologically active fractions eluted from the Sephadex G-25 column. The reference materials to calibrate the Sephadex G-25 column were Blue dextran and acetone, while for calibration of the biodetection system, synthetic oxytocin was used. The extract of ovaries of pregnant sows was separated chromatographically into 8 different, biologically active fractions with distinct UV absorption and molecular weight. One of these fractions showed elution characteristics and biological effect similar to those of synthetic oxytocin in the same biodetection system. The results indicated that acidic acetone extract originating from ovaries of pregnant sows is a rich source of biologically active substances with effects on the myometrium strips in pregnancy. Partial identification of oxytocin-like substances in the ovarian extract verified the effectiveness of the biodetection system in the first steps of research to obtain new, biologically active substances from different unpurified extracts.

Acetone↗
PubMed1985

Accumulation of methane, acetone, and nitrogen in the inspired gas during closed-circuit anesthesia.

During closed-circuit anesthesia, the patient's inspired gas may become progressively contaminated by nonanesthetic gases. We studied the concentrations of methane, acetone, and nitrogen as nonanesthetic gas contaminants in the circuit gas of 16 cases during closed-circuit anesthesia. After a "short" period of denitrogenation (6-8 min), average nitrogen concentration in the closed circuit increased from 6.4 to 16.2%, methane from 4.3 to 22.4 ppm, and acetone from 0.3 to 2.2 ppm. After "long" denitrogenation (33 min), average nitrogen concentration in the closed circuit increased from 1.0 to 5.1%, methane from 3.7 to 17.9 ppm, and acetone from 1.3 to 5.9 ppm. It is concluded that gases stored in tissues or produced within the body can appear in the patient's expired gas during closed-circuit anesthesia. Intermittent flushing of the circuit with high flow gases is suggested to remove these contaminants.

Acetone↗
PubMed1985

Peroxidase-catalyzed formation of triplet acetone and chemiluminescence from isobutyraldehyde and molecular oxygen.

It has been established that the horseradish peroxidase/O2/isobutyraldehyde (IBAL) system leads to triplet acetone and formic acid formation followed by phosphorescence of the triplet acetone (see, for example, Bechara, E.J.H., Faria Oliveira, O.M.M., Durán, N., Casadei de Baptista, R., and Cilento, G. (1979) Photochem. Photobiol. 30, 101-110). In this paper many of the mechanistic details are established. The reaction is initiated by the autoxidation of IBAL to form the peracid (CH3)2CHC = O(OOH). The peracid converts horseradish peroxidase into compound I which in turn is converted into compound II by abstracting the alcoholic hydrogen atom from the enol form of IBAL. This creates a free radical with two resonance forms. (Formula: see text) Addition of molecular oxygen to the latter resonance form creates a peroxy radical which abstracts a hydrogen atom near the active site of the enzyme. The newly formed alpha-peroxide in turn forms a dioxetane-type of intermediate which rapidly decomposes into triplet acetone and formic acid. Compound II reacts with the enol by the same pathway as compound I. Thus native horseradish peroxidase is regenerated. The hydrogen atom abstraction near the enzyme active site may occur directly from ethanol, present to solubilize IBAL or from a group on the enzyme, in which case ethanol participates in a repair mechanism. Phosphate buffer is necessary because it catalyzes the keto-enol conversion of IBAL. Thus horseradish peroxidase participates in a normal peroxidatic cycle. The only chain reaction is the uncatalyzed autoxidation of IBAL, most of which occurs prior to the mixing of IBAL with the oxygenated horseradish peroxidase solution.

Acetone↗
PubMed1978

[Hepatorenal lesions in acute acetone poisoning].

Lesions of the parenchymal organs, not described so far, were found in two males and two females with acute acetone intoxication, besides the well known morbid changes in the gastrointestinal tract and ZNS, regardless the energetic hepato--and nephroprotective treatment. In all patients (one of them inhaled acetone vapours and the rest swallowed the poison per os) liver lesion is present with the corresponding clinical manifestations and changes in the laboratory liver indices. In two of the per orally intoxicated, renal lesion was also found, manifested in a milder degree. The state of the parenchymal organs is necessary to be followed up carefully in case of acute acetone intoxications and a timely treatment with hepato- and nephroprotective drugs in large doses to be applied: glucocorticoids, glucose and levulose solutions, cocarboxylase, lipovitan, vitamin "C", "B1", "B2", "B12", calcium gluconate.

Acetone↗
PubMed1994

[Urea and acetone content in milk as indicators for nutritionally caused fertility disorders of dairy cows].

In 915 records of cows of the breeds German Simmental and German Brown the relationships between fertility parameters and milk urea as well as acetone content were analysed with linear models regarding systematic effects of herd, month, lactation number and breed-Brown-Swiss blood proportion. Milk urea concentration showed significant curvilinear associations to following fertility parameters: days open, days between first and last breeding as well as number of inseminations per service period, conception rate at first insemination after calving and lactational incidence of endometritis. The reproductive traits showed an optimum at a milk urea concentration between 15 and 25 mg/dl. The regression of the fertility parameters on acetone content in milk was nearly linearly decreasing and with the exception of days to first breeding after calving significantly different from zero. An increase of milk acetone by 0.01 mmol/l lead to a prolongation of days from first to last breeding in the service period by more than one day, and to a decrease of conception rate at first insemination by nearly one percent. An approach was developed which is suitable to quantify the influence of milk constituents on fertility traits. The model developed can consider nonlinear relationships, more than one metabolic parameter and systematic effects. Thresholds for milk parameters are no longer needed as the negative effects of the metabolic influences caused by nutritional factors are quantified in terms of fertility parameters.

Acetone↗
PubMedDate not supplied

The use of delta osmolality to predict serum isopropanol and acetone concentrations.

We investigated whether serum delta osmolality will predict the total serum concentration of isopropanol and acetone metabolite. Three isopropanol ingestions were monitored by delta osmolality determinations followed by quantification of serum isopropanol and acetone concentrations. The delta osmolality was established by routine chemical analysis and standard freezing point depression osmometry. Serum isopropanol and acetone levels were quantified by gas chromatography-head space analysis (GC-HS). Patients were initially suspected of having isopropanol intoxication secondary to an elevated delta osmolality discrepancy (measured - calculated > 10 mOsm). Serum concentrations versus delta osmolality were analyzed by linear regression (correlation coefficient r = 0.713; p < 0.05). The delta osmolality paralleled and decreased relative to the total low molecular weight of volatile concentration in each case. In emergencies, delta osmolality may be a screening test to identify rapidly patients at risk for complications associated with isopropanol ingestion when GC-HS is not available.

1-Propanol↗