Effect Of Alcohol Concentration Research Articles

Effects of alcohol concentration and temperature on the dynamics and stability of mutant Staphylococcal lipase

The stability and activity of lipase in organic media are important parameters in determining how quickly biocatalysis proceeds. This study aimed to examine the effects of two commonly used alcohols in industrial applications, methanol (MtOH) and ethanol (EtOH) on the conformational stability and catalytic activity of G210C lipase, a laboratory-evolved mutant of Staphylococcus epidermidis AT2 lipase. Simulation studies were performed using an open-form predicted structure under 30, 40 and 50% of MtOH and EtOH at 25 °C and 45 °C. The overall enzyme structure becomes more flexible with increasing concentration of MtOH and exhibited the highest flexibility in 40% EtOH. In EtOH, the movement of the lid was found to be temperature-dependent with a noticeable shift in the lid position at 45 °C. Lid opening was evidenced at 50% of MtOH and EtOH which was supported by the increase in SASA of hydrophobic residues of the lid and catalytic triad. The active site remained mostly intact. An open-closed lid transition was observed when the structure was re-simulated in water. Experimental evaluation of the lipase stability showed that the half-life reduced when the enzyme was treated with 40% (v/v) and 50% (v/v) of EtOH and MtOH respectively. The finding implies that a high concentration of alcohol and elevated temperature can induce the lid opening of lipase which could be essential for the activation of the enzyme, provided that the catalytic performance in the active site is not compromised. Communicated by Ramaswamy H. Sarma

Synergistic interaction on quasi-binary mixture of amino sulfonate amphoteric surfactant with nonionic diethanolamide induced by glycerol and its concentration

Molecular interaction about a quasi-binary mixtures of an amino sulfonate surfactant, sodium 3-(N-dodecyl ethylenediamino)-2-hydroxypropyl sulfonate (DES), with a fatty acid diethanolamide derived from coconut oil (CDA) in aqueous solutions containing both the glycerol of 0.100 mol/L and 0.200 mol/L was investigated using the surface tension measurement. The interfacial parameters indicate that the mixing of DES with CDA can promote the formation of the more compact distribution of molecules adsorbed in the mixed monolayer, the mixing ratio of the mixture induces the difference in the adsorption behaviors at air–liquid interface, and the standard free energy of adsorption at air–liquid interface implies the benefit of adsorption and the change of adsorption behavior based on both the concentration of glycerol in solutions and the mixing ratio in the mixture. In the framework of pseudo-phase separation model, thermodynamic models including the Clint’s model, the Rubingh’s model and the Maeda’s model were employed to effectively estimate the related micellization and thermodynamic parameters. The nonideal mixing of DES with CDA and their synergistic interactions in the mixed micelle depend on both the mixing ratio of the mixture and the concentration of glycerol in solutions. The abundant amount of DES in mixed micelle will result in the absence of synergistic interaction in aqueous solutions containing the glycerol of 0.100 mol/L, and whereas the abnormal case does not again emerge on increasing the concentration of glycerol to 0.200 mol/L. The compatibility in molecular conformation, the steric hindrance, the electrostatic repulsion and the hydrogen-bond formation are adopted to theoretically explain the interaction behavior. Thermodynamic parameters obtained using the Maeda’s treatments also confirm the absence or the presence of synergistic interaction and the formation of stable mixed micelle. These findings will help with understanding the intermolecular behavior and the effect of alcohol concentration.

Effects of ethyl alcohol on injuries severity according to injury severity scales in pedestrian fatal injury in traffic crashes

Introduction: The dominant cause of injuries in traffic crashes. A significant portion of them affects victims under the influence of ethyl alcohol. The goal of the studies was to assess the correlation between the state of sobriety and the severity of injuries expressed by injury severity scales in fatal pedestrian victims of traffic crashes. Research Material and Method: The data were obtained from the Warsaw Medical University's Department of Forensic Medicine. The analysis covered the data for 2009–2013 and included 200 fatal pedestrian victims hit by passenger cars. The assessment of the effect of risk factors on injury severity expressed in terms of injury severity scales such as Life Threat Indicator (LTI), International Classification based Injury Severity Score (ICISS), Injury Severity Score (ISS) and New Injury Severity Score (NISS), was made using adequately selected methods of statistical analysis. Results: As alcohol concentration increases in women, the values of LTI, ICISS-10 and ICISS-15 decrease, which denotes more severe injuries. In the ISS and NISS, the effect of alcohol concentration on the severity of injuries turned out to be negligible. However, these injuries are significantly heavier in women than in men. According to all the scales used, the older the victims, the milder injuries cause their death. Conclusions: The studies show that ethyl alcohol concentration may harm injury severity, especially in the case of women. The assessment of the severity of injuries in traffic crash victims is significantly influenced by their age and gender. The more risk factors the scale takes into consideration, the more precise is the assessment.

Development and evaluation of orally disintegrating tablets containing the mosapride resin complex.

The purpose of this study was to prepare a mosapride citrate-resin (Amberlite® IRP 88) complex and orally fast-disintegrating tablets of the resin complex. The resinate complex of mosapride-Amberlite® IRP 88, mass ratio 2:1, was prepared in an ethanol-water solution. The effects of alcohol concentration, temperature, and pH of the solution on complex formation were evaluated. The complex physicochemical properties were characterized by differential scanning calorimetry, X-ray diffraction and scanning electron microscopy. Orally disintegrating tablets were prepared by direct compression and were optimized using the response surface method. Optimized orally fast-disintegrating tablets disintegrated within 18 s. The pH dependence of mosapride release from the tablet decreased drug dissolution in simulated saliva, whereas it promptly released in the pH 1.0 solution. The data reported herein clearly demonstrate that tablets containing the mosapride-Amberlite® IRP 88 complex for oral disintegration could be particularly useful for patients with swallowing difficulties.

알코올의 농도에 따른 실크 비드의 적외선 분광 특성

알코올의 농도 변화에 따른 실크단백질의 구조전이 효과에 대하여 살펴보기 위하여 백옥잠 누에고치를 이용하여 실크단백질 용액을 제조하였다. 알코올의 농도를 100%, 70%, 50%로 조절하여 제조한 실크 비드의 적외선 분광 분석을 하였다. 고농도(100%) 알코올로 처리한 실크단백질은 전형적인 <TEX>${\beta}-sheet$</TEX> 구조를 반영하는 <TEX>$1265cm^{-1}$</TEX> 부근에서 흡수대를 보였으며 모델 약물로 사용한 4HR의 특성 피크는 관찰되지 않았다. 알코올의 농도를 70%, 50%로 조절하여 처리한 경우에는 모델 약물의 흡수대인 <TEX>$2933cm^{-1}$</TEX> 부근, <TEX>$1069cm^{-1}$</TEX> 부근, 그리고 <TEX>$973cm^{-1}$</TEX> 부근의 흡수대가 발현되었다. 이러한 결과는 알코올의 농도에 따라 조성되는 실크단백질의 미세 구조에 차이가 있음을 나타내며, 보다 정밀한 실크단백질 구조 제어를 위한 추가 연구가 필요한 것으로 생각된다. The structural transition of silk protein has been induced by various method including alcohol treatment. To know the effect of alcohol concentration on silk beads conformation, silk beads were prepared in different alcohol concentration (100%, 70%, and 50%) and then examined the infrared spectra of silk beads. Silk beads prepared in 100% alcohol showed at <TEX>$1265cm^{-1}$</TEX> attributed <TEX>${\beta}-sheet$</TEX> conformation and did not showed a characteristic absorption peak from model drug. However, silk beads in 70% and 50% alcohol showed some peaks originated from model drug including <TEX>$2933cm^{-1}$</TEX>, <TEX>$1069cm^{-1}$</TEX>, and <TEX>$973cm^{-1}$</TEX>. These results means that the micro-environment of silk beads was affected by alcohol concentration.

Alcohol concentration and carbonation of drinks: The effect on blood alcohol levels

Alcohol absorption and elimination vary considerably amongst individuals, and are subject to influences from a variety of factors. The effects of alcohol concentration and beverage mixer type on the rate of alcohol absorption, in a controlled environment was studied. 21 subjects (12 male, 9 female) consumed a solution containing alcohol, on three separate occasions. The three solutions were, A: Neat vodka (37.5 vol%), B: Vodka mixed with still water (18.75 vol%), C: Vodka mixed with carbonated water (18.75 vol%). The volume of alcohol each subject consumed was determined by Widmark’s equation. The alcohol was drunk in a 5 min period following an overnight fast and breath alcohol concentrations were measured over a 4 h period using a breathalyser. 20/21 subjects absorbed the dilute alcohol at a faster rate than the concentrated alcohol. The difference between the absorption rates was found to be significant ( p < 0.001). The use of a carbonated mixer had varying effects on the alcohol absorption rate. 14/21 subjects absorbed the alcohol with the carbonated mixer at a faster rate, with 7 subjects showing either no change or a decrease in rate. The mean absorption rate for solution C was 4.39 ± 0.45 (mg/100 ml/min), and the difference between this absorption rate and that with the still mixer (1.08 + 0.36) was significant ( p = 0.006).

Effects of self-administered alcohol concentration on the frequency and persistence of rats?? attending to alcohol cues

Observing responses produce contact with stimuli that are to be discriminated and have been considered an animal model of attending. In the observing-response procedure, alternating periods of drug availability versus extinction for one response are not signaled, but a second response (i.e. the observing response) produces stimuli signaling whether drug is available or not. This experiment examined the effects of the concentration of self-administered alcohol and increases in observing-response requirement on rats' observing alcohol stimuli. In addition, the effects of alcohol concentration on the persistence of observing were examined when alcohol was no longer available. Results showed that observing tracked bitonic changes in the number of alcohol deliveries rather than monotonic increases in total alcohol consumption resulting from increases in alcohol concentration. Increasing the observing-response requirement decreased the number of stimulus presentations earned. The resultant decreases in time spent in the presence of the alcohol stimulus were associated with decreases in alcohol consumption. During extinction of alcohol responding, observing was more persistent when it produced a stimulus previously associated with a higher alcohol concentration. Finally, responding for alcohol was more resistant to extinction in the presence of an observing-response-produced alcohol stimulus than in its absence, but did not depend on alcohol concentration. These results suggest that increases in the difficulty of obtaining access to alcohol cues can decrease alcohol consumption by reducing contact with those cues. In addition, if observing behavior in the present procedure is analogous to attending to alcohol cues, the results suggest that attending to alcohol cues is more persistent with cues previously associated with higher doses, and that the persistence of attending to alcohol cues and their impact on drinking may be dissociable.

Influence of Solvent Composition on the Kinetics of Cyclooctene Epoxidation by Hydrogen Peroxide Catalyzed by Iron(III) [tetrakis(pentafluorophenyl)] Porphyrin Chloride [(F20TPP)FeCl

The epoxidation of cyclooctene catalyzed by iron(III) [tetrakis(pentafluorophenyl)] porphyrin chloride [(F20TPP)FeCl] was investigated in alcohol/acetonitrile solutions in order to determine the effects of the alcohol composition on the reaction kinetics. It was observed that alcohol composition affects both the observed rate of hydrogen peroxide consumption (the limiting reagent) and the selectivity of hydrogen peroxide utilization to form cyclooctene epoxide. The catalytically active species are formed only in alcohol-containing solvents as a consequence of (F(20)TPP)FeCl dissociation into [(F20TPP)Fe(ROH)]+ cations and Cl- anions. The observed reaction kinetics are analyzed in terms of a proposed mechanism for the epoxidation of the olefin and the decomposition of H2O2. The first step in this scheme is the reversible coordination of H2O2 to [(F20TPP)Fe(ROH)]+. The O-O bond of the coordinated H2O2 then undergoes either homolytic or heterolytic cleavage. The rate of homolytic cleavage is found to be independent of alcohol composition, whereas the rate of heterolytic cleavage increases with alcohol acidity. Heterolytic cleavage is envisioned to form iron(IV) pi-radical cations, whereas homolytic cleavage forms iron(IV) hydroxo cations. The iron(IV) radical cations are active for olefin epoxidation, whereas the iron(IV) cations catalyze the decomposition of H2O2. Reaction of iron(IV) pi-radical cations with H2O2 to form iron(IV) hydroxo cations is also included in the mechanism, a process that is favored by alcohols with a high charge density on the O atoms. The proposed mechanism describes successfully the effects of H2O2, cyclooctene, and porphyrin concentrations, as well as the effects of alcohol concentration.

The effect of methanol and ethanol cross-over on the performance of PtRu/C-based anode DAFCs

In the present work, the cross-over rates of methanol and ethanol, respectively, through Nafion®-115 membranes at different temperatures and different concentrations have been measured and compared. The changes of Nafion®-115 membrane porosity in the presence of methanol or ethanol aqueous solutions were also determined by weighing vacuum-dried and alcohol solution-equilibrated membranes. The techniques of anode polarization and adsorption stripping voltammetry were applied to compare the electrochemical activity and adsorption ability, respectively. To investigate the consequences of methanol and ethanol permeation from the anode to the cathode on the performance of direct alcohol fuel cells (DAFCs), single DAFC tests, with methanol or ethanol as the fuel, have been carried out and the corresponding anode and cathode polarizations versus dynamic hydrogen electrode (DHE) were also performed. The effect of alcohol concentration on the performance of PtRu/C anode-based DAFCs was investigated.It was found that ethanol shows lower cross-over rates than methanol through the Nafion® membrane in spite of the higher membrane porosity resulted in presence of ethanol aqueous solutions. Furthermore, it was found that ethanol presents less negative effect on the cathode performance due to both its smaller permeability through Nafion® membrane and its slower electrochemical oxidation kinetics over Pt/C cathode.

Interfacial tensions upon the addition of alcohols to phenylalkane sulfonate monoisomer systems

The effects of n-pentanol and n-octanol on the interfacial tensions of phenylalkane sulfonate monoisomer systems against n-alkanes were investigated for elucidating the mechanism of ultra-low interfacial tensions related to enhanced oil recovery. The addition of n-pentanol to phenylalkane sulfonate monoisomer systems had little effect on the interfacial tensions of 1-phenylalkane sulfonate systems, whereas n-octanol could lower their interfacial tensions up to 1–2 orders for some n-alkanes. n-Pentanol could lower the interfacial tensions of 3-phenyltetradecane sulfonate against n-hexane, n-heptane and n-octane, but n-octanol had little effect on the interfacial tensions of 3-phenyltetradecane sulfonate. The interfacial tensions of 5-phenyltetradecane sulfonate could be lowered by the addition of n-pentanol, but increased upon the addition of n-octanol. The effects of alcohol concentration and time on interfacial tensions were also researched to show that interfacial tensions of 5-phenyltetradecane sulfonate solution increased with time at whether lower (0.04%, vol%) or higher (0.4%, vol%) n-octanol concentrations.

Effect of alcohol concentration and electrode composition on the ethanol electrochemical oxidation

The electrochemical oxidation on platinum and platinum rhodium bimetallic electrodes wasstudied by Differential Electrochemical Mass Spectrometry for several ethanol concentrations in solution.It is found that increasing the ethanol concentration the production of the partially oxidized products(acetaldehyde) increases as the concentration increases. On the other hand, addition of 25% at. of rhodiumincreases the full oxidation to CO 2 . Another interesting result observed is a correlation between theintensity of the dehydrogenations peak at 0.3 V vs. RHE and the CO 2 yield for the different ethanolconcentration studied.

Effect of alcohol concentration and electrode composition on the ethanol electrochemical oxidation

The electrochemical oxidation on platinum and platinum rhodium bimetallic electrodes was studied by Differential Electrochemical Mass Spectrometry for several ethanol concentrations in solution. It is found that increasing the ethanol concentration the production of the partially oxidized products (acetaldehyde) increases as the concentration increases. On the other hand, addition of 25% at. of rhodium increases the full oxidation to CO2. Another interesting result observed is a correlation between the intensity of the dehydrogenations peak at 0.3 V vs. RHE and the CO2 yield for the different ethanol concentration studied.

Wetting Study of Hydrophobic Membranes via Liquid Entry Pressure Measurements with Aqueous Alcohol Solutions

A new concept of liquid entry pressure measurements is applied to study the hydrophobicity of microporous membranes for aqueous alcohol solutions. The effects of alcohol concentration, type of alcohol, and temperature on liquid entry pressure of the membrane have been studied. Two theoretical equations for the determination of membrane pore size have been proposed. The former equation was developed taking into account the deviation from the Laplace–Young equation due to the membrane structure by means of the structure angle. The latter equation was established considering only the range of alcohol concentration in which the dispersion component of liquid surface tension remains practically constant. Hydrophobicity has been expressed in terms of wetting surface tension, γLw. Based on these measurements, the maximum concentration before the spontaneous wetting occurs would be predicted.

Separation of hydrocortisone and epi-hydrocortisone by solvent extraction

Solvent extraction, instead of traditional crystallization, is suggested as a new method for separation of hydrocortisone and its optical isomer, epi-hydrocortisone. The extraction behavior of alcohols, ketones, esters, ethers and chlorinated hydrocarbons was studied experimentally. For the industrial separation process it was found that the best solvents are n-butyl acetate or chloroform. The distribution coefficients of hydrocortisone and epi-hydrocortisone in an n-butyl acetate/water system at 17°C were found to be 9·98 and 2·62, respectively, and 5·57 and 1·93, respectively, in a chloroform/water system at 17°C. When n-butyl acetate or chloroform solution of crude hydrocortisone (the mixture of hydrocortisone, epi-hydrocortisone and other steroid impurities) was scrubbed by deionized water in a nine-stage cross-current at 25°C, the organic phase hydrocortisone purity increased from 78·10% to 98·22% (wt%) for the n-butyl acetate case and from 78·10% to 98·02% (wt%) for the chloroform case. The medicinal standard for hydrocortisone was attained. The effects of alcohol concentration, temperature, salting-out and pH on extraction are also discussed. ©1997 SCI

Chiral resolution of 4-substituted pyrrolidin-2-ones using high-performance liquid chromatography on cellulose and amylose chiral stationary phases

Analytical HPLC methods using derivatized cellulose and amylose chiral stationary phases were developed for the separation of the enantiomers of 4-substituted pyrrolidin-2-ones. Separations were performed using normal-phase methodology with a mobile phase of n-hexane-alcohol (ethanol or 2-propanol) in various percentages, and a silica-based cellulose tris-3,5-dimethylphenylcarbamate (Chiralcel OD), or amylose tris-( S)-1-phenylethylcarbamate (Chiralpak AS). The mobile phase and the chiral stationary phase were varied to achieve the best resolution. The effects of alcohol concentration, various aliphatic alcohols in the mobile phase were studied. The effects of substitution were analysed. Baseline separation was easily obtained in many cases.

清酒酵母の膜脂肪酸組成に及ぼす培地のアルコール濃度の影響

清酒酵母の膜脂肪酸組成に及ぼす培地のアルコール濃度の影響

Some effects of ethyl alcohol on the growth of rumen bacteria

The effects of ethyl alcohol on the growth rate and yield of representative isolates of obligately anaerobic rumen bacteria were studied. Yield was monitored as turbidity at 600 nm until stationary phase was obtained and quantitated as protein per milliter. Rate was determined as the fastest rate of turbidity doubling. With very few exceptions, within the concentration range allowing growth, no effects of alcohol concentration were observed on rate, but substantial effects were found on yield. Growth of most of the organisms studied was completely inhibited at an alcohol concentration between 3% and 7% vol/vol, but the growth ofBacteroides amylophilus andRuminococcus flavefaciens was drastically reduced or eliminated at a 1% alcohol concentration. It is likely that major physiological and biochemical differences exist among anaerobic rumen bacteria, and taxonomically similar organisms, as a function of alcohol exposure.

Electron solvation in alcohol-alkane mixtures

The effect of alcohol concentration on the conductivities of solutions of n-propanol in c-hexane and iso-octane and of t-butanol in c-hexane following electron pulse irradiation, are quantitatively consistent with the existence of an equilibrium between mobile electrons in the hydrocarbon and electrons solvated by alcohol dimers. For methanol solutions in iso-octane the observations suggest electron solvation by a larger association of alcohol molecules (ca. 6).

The effects of alcohol concentration on schedule-induced alcohol drinking

Rats were made polydipsic for water by the free delivery of food pellets on a fixed-time 1-min schedule. Alcohol concentrations of 2.5%, 5.0%, 7.5%, and 10% were then substituted for the water. An inverse relationship between fluid consumption and alcohol concentration was observed; however, the function relating grams of absolute alcohol consumed to concentration increased monotonically.

Effect of Alcohol Concentration and Saturation of the Acid Alcohol with K2Ptcl6 in the Analysis of Potash in Fertilizers

Effect of Alcohol Concentration and Saturation of the Acid Alcohol with K2Ptcl6 in the Analysis of Potash in Fertilizers