Low Concentrations Of Ethanol Research Articles

Electrochemical corrosion tests in an environment of low-conductive ethanol-gasoline blends: Part 1 – Testing of supporting electrolytes

Bioethanol is a promising biofuel that can be used in the pure form or in the form of ethanol-gasoline blends (EGBs) as a transportation fuel. The combustion of bioethanol in petrol engines is associated with several problems, with bioethanol corrosion effects on metallic construction engine parts being one of the most serious ones. Electrochemical methods, such as electrochemical impedance spectroscopy, measurement of polarization characteristics (Tafel scan), etc., have been found to be efficient in studying corrosion effects in metal-EGB systems. However, a fuel environment with a low ethanol content (such as E10 and lower) has low conductivity, which can be a limiting factor for electrochemical corrosion studies. Supporting electrolytes can be used to increase the conductivity of such environments. These supporting electrolytes must be inert against the occurring corrosion reactions in order not to negatively affect the obtained corrosion data. In this work, we tested four potential supporting electrolytes (lithium perchlorate, tetrabutylammonium tetrafluoroborate, potassium hexafluorophosphate, and tetrabutylammonium bromide) to be used for the electrochemical corrosion tests on mild steel in the environment of an E85 fuel. In our study, we demonstrated that tetrabutylammonium tetrafluoroborate (TBATFB) can successfully be used for short-term corrosion studies as it exhibited minimum effects on the obtained electrochemical data even at a relatively high concentration of about 500 mg/L. The use of this supporting electrolyte can substantially facilitate electrochemical corrosion studies in less conductive media such as EGBs with a low content of ethanol. • Corrosion behavior of mild steel in the environment of E85 fuel was tested. • Electrochemical impedance spectroscopy and Tafel scan were used as testing methods. • Applicability of four supporting electrolytes for the testing methods was studied. • TBATFB was found to be usable for short-term corrosion studies by the testing methods.

In vitro long-term culture of isolated ovine preantral follicles: Influence of ethanol on steroid production, oocyte meiotic resumption, and metabolomic profile.

Ethanol is used routinely to dilute cell culture media supplements with little or no water solubility. This study evaluates the effect of low concentration of ethanol on the follicular development, oocyte maturation, hormone production, gene expression, and metabolomics profile of spent culture medium after long-term culture of isolated ovine preantral follicles. For this, follicles were cultured for 18 days in α-Minimum Essential Medium+ alone (control treatment) or supplemented with 100 ng/mL recombinant bovine FSH (rbFSH treatment) or with 0.2%-v/v ethanol (ethanol treatment). Ethanol treatment increased the percentage of degenerated follicles and oocytes significantly, however, it showed the highest estradiol secretion. Also, the rate of meiosis resumption was higher in ethanol treatment than Control treatment. Ethanol treatment decreased the mRNA levels of B-cell lymphoma 2 (BCL2), BCL2 associated X, Aquaporin 3, Connexin 43, Inhibin Subunit Beta A, kit ligand, Heat Shock Protein (HSP A1A) significantly when compared to the Control treatment. However, mRNA levels of cytochrome P450 family 19, and FSH receptors were significantly higher in ethanol treatment than in the Control treatment. The levels of some metabolites, which are likely amino acids, lipids, an analog of Cyclic guanosine monophosphate, and a derivative of phosphoinositol phosphate metabolism, had higher relative concentrations in ethanol and rbFSH treatments than the Control treatment. In conclusion, ethanol addition augmented the follicular and oocyte degeneration rates but increased the estradiol production and the meiotic resumption. Furthermore, the follicular metabolomic profile was similar between ethanol and rbFSH treatments being both treatments; however, different from the Control treatment.

Physicochemical composition and fermentation kinetics of a novel Palm Sap-based Kefir Beverage from the fermentation of Borassus aethiopum Mart. fresh sap with kefir grains and ferments

Palm sap collected (sugary juice) from palm trees is very widespread in the intertropical regions of Asia, America and Africa. This study aimed to evaluate the use of kefir grains and ferments as starters for the fermentation of fresh palm sap (PS) from Borassus aethiopum Mart. to produce new kefir-like beverages (KLBs). The batch fermentation was performed statically at room temperature (22 °C) during 48 h. Physicochemical analysis were performed using standard and HPLC methods. The KLBs (kefir-like beverages) from PS showed low ethanol and glycerol contents ranging from 0.84 ± 0.14 to 17.30 ± 2.06 g/L (0.07 to 1.38% v/v) and 0 to 0.67 g/L respectively. The pH value decreased significantly during 24 h of fermentation and ranging from 3.98 to 4.40 at the end of fermentation. The organic acids (lactate, acetate, propionate, citrate, succinate and pyruvate) were detected in KLBs from PS. There was an increase in the content of lactate, acetate, propionate and succinate during fermentation process, except citrate content. Lactate and acetate content reached maximum values ranging between 5.18 and 9.31 g/L, 0.94 and 1.69 g/L respectively. Sucrose concentration decreased significantly and reached a value ranging from 0 to 0.84 g/L, except in KLBs fermented using milk ferments (9.45 g/L). The study showed that water and milk kefir grains as well as kefir ferments were well adapted to ferment Borassus aethiopum Mart. fresh sap for KLBs production. Palm sap could be an ideal alternative base substrate to produce non-dairy probiotic fermented beverage with low ethanol and sugar contents.

Non-Alcoholic and Craft Beer Production and Challenges

Beer is the most consumed alcoholic beverage in the world and the third most popular beverage after water and tea. Emerging health-oriented lifestyle trends, demographics, stricter legislation, religious prohibitions, and consumers’ preferences have led to a strong and steady growth of interest for non-alcoholic beers (NABs), low-alcohol beers (LABs), as well for craft beers (CBs). Conventional beer, as the worlds most consumed alcoholic beverage, recently gained more recognition also due to its potential functionality associated with the high content of phenolic antioxidants and low ethanol content. The increasing attention of consumers to health-issues linked to alcohol abuse urges breweries to expand the assortment of conventional beers through novel drinks concepts. The production of these beers employs several techniques that vary in performance, efficiency, and usability. Involved production technologies have been reviewed and evaluated in this paper in terms of efficiency and production costs, given the possibility that craft brewers might want to adapt them and finally introduce novel non-alcoholic drinks in the market.

Enhancement of biomass conservation and enzymatic hydrolysis of rice straw by dilute acid-assisted ensiling pretreatment

To reduce the cost of lignocellulosic pretreatment, rice straw was ensiled with dilute formic acid (FA, 0, 0.2, 0.4, and 0.6%) for 3, 6, 9, 15 and 30 days, and evaluated its effects on fermentation dynamics, lignocellulosic degradation and enzymatic hydrolysis. The results showed that the application of FA, especially at 0.6% level, reduced total fermentation losses of the resulting silages, as evidenced by low dry matter loss, ammonia nitrogen and ethanol content. Meanwhile, the 0.6% FA application promoted hemicellulose removal (232.41 vs 187.52 g/kg DM) and xylose production (0.35 vs 2.80 g/kg DM). The glucose yield and cellulose convertibility of rice straw increased after 30 days of ensiling, and further enhanced by the 0.6% FA application. In conclusion, the 0.6% FA-assisted ensiling pretreatment improved both biomass preservation, hemicellulose removal and enzymatic hydrolysis of rice straw, which is beneficial to the subsequent biofuel production chain.

Protective Role of Low Ethanol Administration Following Ischemic Stroke via Recovery of KCC2 and p75NTR Expression

A striking result from epidemiological studies show a correlation between low alcohol intake and lower incidence for ischemic stroke and severity of derived brain injury. Although reduced apoptosis and inflammation has been suggested to be involved, little is known about the mechanism mediating this effect in vivo. Increase in intracellular chloride concentration and derived depolarizing GABAAR-mediated transmission are common consequences following various brain injuries and are caused by the abnormal expression levels of the chloride cotransporters NKCC1 and KCC2. Downstream pro-apoptotic signaling through p75NTR may link GABAA depolarization with post-injury neuronal apoptosis. Here, we show that changes in GABAergic signaling, Cl− homeostasis, and expression of chloride cotransporters in the post-traumatic mouse brain can be significantly reduced by administration of 3% ethanol to the drinking water. Ethanol-induced upregulation of KCC2 has a positive impact on neuronal survival, preserving a large part of the cortical peri-infarct zone, as well as preventing the massive post-ischemic upregulation of the pro-apoptotic protein p75NTR. Importantly, intracortical multisite in vivo recordings showed that ethanol treatment could significantly ameliorate stroke-induced reduction in cortical activity. This surprising finding discloses a pathway triggered by low concentration of ethanol as a novel therapeutically relevant target.

Barley-sorghum craft beer production with Saccharomyces cerevisiae, Torulaspora delbrueckii and Metschnikowia pulcherrima yeast strains

The use of different yeast strains contributes to obtain insights into beer products with diverse sensory characteristics. In this study, three yeast species of different genera were selected to evaluate their fermentation performance and sensory profile for barley-sorghum beer production. Baley-sorghum wort was produced with 12.5°P and fermented with Saccharomyces cerevisiae, Torulaspora delbrueckii and Metschnikowia pulcherrima yeast strains. Differences were observed in terms of fermentation time and ability to ferment maltose. S. cerevisiae attenuated initial maltose concentration within 72 h, while M. pulcherrima and T. delbrueckii performed fermentation within 120 and 192 h, respectively. Both yeast strains simultaneously produced 11% and 23% lower ethanol concentrations, compared to S. cerevisiae with 37.9 g/L. Wort fermented with T. delbrueckii showed residual maltose concentration of 19.7 ± 4.1 g/L, resulting in significantly enhanced beer sweetness. S. cerevisiae produced significantly increased levels of higher alcohols, and obtained the highest scores for the sensory attribute body perception. Beer produced with T. delbrueckii contained significantly lower fermentative 2,3-butanediol and 2-methyl-1-butanol volatiles; this beer also showed reduced body perception. Beer conditioned with T. delbrueckii was significantly preferred over M. pulcherrima. Besides S. cerevisiae with high fermentative power, T. delbrueckii and M. pulcherrima were found to have reduced maltose fermenting abilities and provide significantly different sensory attributes to barley-sorghum beers.

Fabrication of citric acid-modified starch nanoparticles to improve their thermal stability and hydrophobicity

Starch nanoparticles (SNPs) were reacted at 130 °C for 1.5 h in the presence of citric acid (30 %) to enhance their thermal stability and hydrophobicity. Citric acid content in SNP was controlled by washing with different concentrations of ethanol (95 %, 70 % and 60 %) for 2, 5 and 10 min and then subjected to heat treatment at 130 °C. After the modification, the peak at 1732 cm−1 representing ester bond was observed via FT-IR, and the intensity of the peak was decreased with a lower ethanol content in washing medium. For the 60 % ethanol condition, the granular structure was promptly fragmented into particles less than 50 nm in the aqueous solution. The modification enhanced the thermal stability and hydrophobicity of the SNPs. The modified SNPs was used as a nano-vehicle wall material for encapsulating beta-carotene as a model hydrophobic material. Approximately 80 % beta-carotene was encapsulated in the modified SNPs.

Low concentration ethanol sensor based on graphene/ZnO nanowires

Metal-oxide based gas sensors are widely used as the gas sensing elements in industrial and residential areas. Many efforts have been made to increase sensitivity and reduce the working temperature of metal-oxide based gas sensors. In this paper, ZnO nanowires (NWs) were successfully grown on graphene (Gr) nanosheets by the hydrothermal method. The synthesized Gr/ZnO NWs nanocomposite were investigated as the sensing material. Not only is the sensor response much higher, it also works in a lower working temperature toward a low concentration of ethanol in comparison with pure ZnO NWs. The optimum working temperature is reduced from 200 °C in pure ZnO NWs to 125 in Gr/ZnO NWs sensor. The maximum response of the Gr/ZnO NWs sensor is 26, which is approximately enhanced twice as much as the pure ZnO NWs sensor. The lower limit of detection (LLOD) of the proposed sensor is as low as 1 ppm ethanol vapor. The sensor was shown a high response, good selectivity, fast response toward ethanol vapor, excellent repeatability, and low sensitivity toward a high relative humidity, as well as remarkable long-term stability.

Low Ethanol Concentrations Promote Endothelial Progenitor Cell Capacity and Reparative Function.

Background Endothelial progenitor cells (EPCs) are recruited to injured endothelium and contribute to its regeneration. There is evidence that moderate ethanol consumption prevents the development and progression of atherosclerosis in a variety of in vitro and in vivo models and increases the mobilization of progenitor cells. Furthermore, there are studies that identified ethanol at low concentration as a therapeutic tool to mobilize progenitor cells in peripheral blood. At the same time, the cell number of EPCs represents a close link to cardiovascular system constitution and function and contributes to cardiovascular risk. The aim of this study was to evaluate the effect of low dose ethanol on typical features of endothelial colony-forming cells (ECFCs), a proliferative subtype of EPCs. Methods and Results We tested whether ethanol impacts the functional abilities of ECFC (e.g., migration, tube formation, and proliferation) using in vitro assays, the intercommunication of ECFC by exploring cell surface molecules by flow cytometry, and the expression of (anti-)angiogenic molecules by ELISA. Low concentrations of ethanol concentration promoted migration, proliferation, and tubule formation of ECFC. The expression of the cell surface marker VE-cadherin, a protein which plays an important role in cell-cell interaction, was enhanced by ethanol, while (anti-)angiogenic molecule expression was not impacted. Conclusion Ethanol at moderate concentrations increases the angiogenic abilities of endothelial progenitor cells thus possibly contributing to vasoprotection.

Plasmonic Microbubble Dynamics in Binary Liquids.

The growth of surface plasmonic microbubbles in binary water/ethanol solutions is experimentally studied. The microbubbles are generated by illuminating a gold nanoparticle array with a continuous wave laser. Plasmonic bubbles exhibit ethanol concentration-dependent behaviors. For low ethanol concentrations (fe) of ≲67.5%, bubbles do not exist at the solid–liquid interface. For high fe values of ≳80%, the bubbles behave as in pure ethanol. Only in an intermediate window of 67.5% ≲ fe ≲ 80% do we find sessile plasmonic bubbles with a highly nontrivial temporal evolution, in which as a function of time three phases can be discerned. (1) In the first phase, the microbubbles grow, while wiggling. (2) As soon as the wiggling stops, the microbubbles enter the second phase in which they suddenly shrink, followed by (3) a steady reentrant growth phase. Our experiments reveal that the sudden shrinkage of the microbubbles in the second regime is caused by a depinning event of the three-phase contact line. We systematically vary the ethanol concentration, laser power, and laser spot size to unravel water recondensation as the underlying mechanism of the sudden bubble shrinkage in phase 2.

Combinatorial ethanol treatment increases the overall productivity of recombinant hG-CSF in E. coli: a comparative study.

Human granulocyte colony-stimulating factor (hG-CSF) is a cytokine that regulates the proliferation, maturation, and differentiation of precursor cells to neutrophils. In the present study, we report the feasibility of inducing recombinant hG-CSF expression (rhG-CSF) in a pET vector system by combinatorial induction using low-concentration ethanol, IPTG, and lactose and auto-induction media (AIM). The coding sequence of hG-CSF transcript variant 2 was expressed in pET14 vector, and the effect of combinatorial induction was analyzed on inclusion body (IB) formation, biomass, protein purification, and bioactivity. Results showed that there was an inverse relationship between the temperature and soluble expression of rhG-CSF. Three-step washing with Triton-X, 2M, and 5M urea resulted in the maximum recovery of IBs. Combinatorial single-spike induction with IPTG, ethanol, and lactose in a batch culture led to a 3-fold increase in the expression of rhG-CSF. It was also observed that low concentration of ethanol (1-3% v/v) could be used in lieu of IPTG for inducing the rhG-CSF protein expression without adversely affecting biomass production. A 2.4-fold increase in productivity was obtained in LB-AIM media with combinatorial ethanol induction, and the overall yield of 2.8g/L rhG-CSF was found. The purified rhG-CSF was bioactive and increased the cellular proliferation of umbilical cord blood-derived mesenchymal stem cells (U-MSC) by 29%. In conclusion, our study shows that combined ethanol induction can enhance the expression of rhG-CSF with three-step washing for recovery of the proteins from IBs and a single-step purification of rhG-CSF by affinity chromatography. KEY POINTS: • Low concentration of ethanol (1-3%) could be used in lieu of IPTG for inducing rhG-CSF expression. • Combinatorial single-spike induction with IPTG, ethanol, and lactose improved rhG-CSF expression. • Purified rhG-CSF was bioactive and increased the proliferation of U-MSC.

Application of granular cold-water-swelling starch as a clean-label oil structurant

The demand for the reduced consumption of saturated lipids has increased due to the associated health concerns. One promising approach to reduce the consumption of solid fat is oil structuring, but the use of non-label-friendly structurants poses a challenge to food industry. Herein, we proposed using granular cold-water-swelling starch as a clean-label and affordable oil structurant for the reduction of solid fat. Pre-gelatinized starch was first prepared by heating corn starch in different concentrations of aqueous ethanol, generating different degrees of pre-gelatinization. Lower ethanol concentration produced starch with higher water-holding capacity and higher swelling power. Structured oil was then prepared by dispersing the hydrated swollen starch in canola oil, followed by centrifugation to collect the solid sediment. The prepared structured oil was evaluated on rheological behavior, texture profile, color, and physical stability. The results showed that a higher degree of pre-gelatinization and a higher hydrated degree of the swollen starch led to a decrease in the rheological moduli (G′ and G″) and an elongation of the linear viscoelastic region of the structured oil, which also contributed to lower firmness and stronger stickiness. The underlying reasons were attributed to differences in particle rigidity and granular flocculation. In addition, the presence of a surfactant inhibited the flocculation of the swollen starch, and affected sample texture. By manipulating the properties of cold-water-swelling starch, this study showed that we could fine-tune the texture of the structured oil, thus demonstrating a promising and scalable approach for reducing solid fats in the daily diet.

Enhancing room temperature ethanol sensing using electrospun Ag-doped SnO2–ZnO nanofibers

The present study reports room temperature ethanol sensing with improvement in response and recovery times using Ag-doped SnO2–ZnO composite nanofibers. A comparative study of nanofibers of solo SnO2, SnO2–ZnO nanocomposite and Ag-doped SnO2–ZnO nanocomposite is presented. Nanofibers of tin oxide and zinc oxide are deposited on low-cost aluminum electrodes using electrospinning technique to analyze their gas sensing characteristics towards volatile organic compounds, especially ethanol. The effect of Ag doping on nanocomposite of SnO2 and ZnO has been studied and analyzed in terms of various gas sensing parameters viz. % response, response/recovery time, and selectivity. Ag-doped SnO2–ZnO nanofibers have shown excellent response towards low concentration of ethanol (38.78% for 0.5 ppm) at room temperature (RT) with quick response and recovery times. X-ray diffraction, X-ray photoelectron spectroscopy, I–V characterization, energy dispersive X-ray spectroscopy, and scanning electron microscopy characterizations are done to show the crystallite size, valence state, electrical properties, elemental analysis, and surface morphology of the deposited nanofibers, respectively. The effect of doping on the surface characteristics is also analyzed by calculating and comparing the crystallite size of doped and undoped nanofibers. Moreover, the use of sol–gel process route, electrospinning deposition technique, and aluminum as the electrode and glass substrate make the fabrication of the sensor very cost effective.

Evaluation and optimization of microwave‐assisted extraction of bioactive compounds from eggplant peel by‐product

A three-level five-factor central composite design was used for microwave-assisted extraction of bioactive compounds from eggplant peel. The extraction yields, total phenolic content (TPC), total flavonoid content (TFC), total anthocyanin content (TAC), and DPPH radical scavenging activity, reported as IC50, were optimized by changing the microwave power, extraction time, liquid–solid ratio, ethanol concentration, and pH of solvent. The extraction yield, TAC, TPC, and TFC significantly increased (p < .01) parallel to the increase in microwave power and the use of lower ethanol concentrations and lower liquid–solid ratios. The maximum predicted extraction yield (3.27%), TPC (1,049.84 µg GAE/ml), TFC (130.40 µg QE/ml), and TAC (6.99 mg/L) and the minimum predicted IC50 (0.52 ml/mg) were simultaneously obtained when power, extraction time, liquid–solid ratio, ethanol concentration, and pH of solvent were 269.82 W, 7.98 min, 5.01 ml/g, 73.49%, and 3.06%, respectively. Overall, bioactive compounds could be effectively extracted from eggplant peels via optimized microwave conditions. Practical applications The processing of eggplants by industries inevitably generates large amounts of peel as food waste. This valuable by-product comprises anthocyanins that are a type of polyphenol with potential applications as natural food colorant and antioxidant. In this research, microwave-assisted extraction (MAE) was performed as an effective method for the extraction of anthocyanins and phenolic and flavonoid compounds from eggplant peel. Afterward, the yield of the mentioned bioactive compounds derived from eggplant peel extracts was optimized through managing several MAE parameters such as microwave power, extraction time, liquid–solid ratio, ethanol concentration, and pH of the solvent. Such new information concerning the recovery of these valuable components from waste can improve the economy for canning industries and minimize the potential pollution of these wastes.

Traditional and Artisanal Beverages in Nigeria: Microbial Diversity and Safety Issues

A review of up to 90 articles on the microorganisms associated with important artisanal or traditional beverages in Nigeria was carried out. This resulted in an overview of the prevalent microorganisms associated with soymilk, nono (fermented cow milk), tiger nut milk, yoghurt, kunu, zobo, palm wine and the local beers pito and brukutu. The bacteria genera, namely Bacillus, Escherichia, Lactobacillus, Staphylococcus, and Streptococcus, were detected in all nine beverages. On the contrary, this survey resulted in finding that the genera Saccharomyces, Aspergillus, Candida, and Penicillium were the eukaryotic microorganisms isolated in all beverages. The occurrence of fungal isolates, which can be responsible for producing mycotoxins, is a concern and shows the need for post-production tests. Overall, there is a low prevalence of bacteria associated with hygiene, especially the Escherichia genus in alcoholic beverages such as palm wine, pito and burukutu, which may be due both to a low acidity and high ethanol content. However, the prevalence of hygiene indicator genera was higher in nonalcoholic drinks, probably because of incorrect practices during processing. The magnitude of the production and sales of unregulated local beverages in Nigeria has reached the stage where significant regulation and food safety standards are required to safeguard public health. An opportunity exists to monitor and characterize the microbial flora of the artisanal beverages using molecular methods at all stages of production and storage.

Phenolic Compound Profiles in Alcoholic Black Currant Beverages Produced by Fermentation with Saccharomyces and Non-Saccharomyces Yeasts.

Alcoholic beverages with low ethanol contents were produced by fermenting black currant juice with Saccharomyces and non-Saccharomyces yeasts without added sugar. The effects of different yeasts on the phenolic compounds (anthocyanins, hydroxycinnamic acids, flavonols, and flavan-3-ols) and other selected constituents (the ethanol content, residual sugars, organic acids, and color) of the black currants were assessed. Single yeast-fermented beverages had higher ethanol contents (3.84–4.47%, v/v) than those produced by sequential fermentation. In general, the fermentation of black currant juice increased the contents of organic acids and flavonols, whereas anthocyanin contents decreased. All of the fermentations decreased the contents of glycosylated nitrile-containing hydroxycinnamic acids, resulting in higher contents of the corresponding aglycons. Fermentation with Saccharomyces bayanus resulted in lower anthocyanin and organic acid contents compared to the other yeasts. Sequential fermentations with Saccharomyces cerevisiae and Metschnikowia pulcherrima led to the highest total hydroxycinnamic acids and anthocyanins among all of the fermentations.

High-performance ethanol sensor based on In2O3 nanospheres grown on silicon nanoporous pillar array

At the interfaces between different materials, electronic systems with unusual electronic properties can be generated. Here, we report an In2O3/Si nanoheterostructures prepared by depositing indium grain film on silicon nanoporous pillar array (Si-NPA) by a vacuum thermal evaporation technique and a following thermal oxidation method. The composition and morphology of In2O3 film on Si-NPA were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), which disclosed that the In2O3 film is composed of a layer of In2O3 nanospheres with massive interfaces coating on Si-NPA. The sensor based on In2O3/Si-NPA showed high selectivity to ethanol, and demonstrated a high response of 3.38 at the extremely low ethanol gas concentration of 2 ppm. The response and recovery times to 100 ppm were 3 s and 39 s, respectively. The high performance was attributed to the specific nanostructure feature of In2O3/Si-NPA sensor, large specific surface area and massive surface active sites. Moreover, the impressive features of In2O3/Si-NPA heterostructures have been discussed in detail from its geometrical and band structure. These results observed here indicate that the In2O3/Si-NPA sensor may be a promising sensing candidate for detecting low-concentration ethanol.

Effect of Mg-doping ZnO nanoparticles on detection of low ethanol concentrations

Pure and Mg-doped ZnO (3 at. %) nanoparticles were prepared based to sol–gel route under supercritical conditions of ethyl alcohol. The samples were characterized by certain techniques. XRD patterns showed the hexagonal wurtzite crystalline structure of ZnO and Mg-doped ZnO nanoparticles. The TEM image demonstrates the hexagonal shape and the nanometric size of the nanostructures. SEM images show the presence of hexagonal like shape nanoparticles and the increase of grain size for the Mg doped sample. The corresponding EDX analysis proves the existence of Mg with low concentrations and shows coherent distribution of high concentrations of Zn and O elements. The UV–Vis–NIR spectroscopy exhibits high absorbance of the prepared samples in the UV range. Thereafter, the effect of doping ZnO by Mg on sensing properties has been investigated. The obtained results outline an enhancement in sensing performances for Mg doped ZnO based sensor, which exhibits, competitive response and recovery times, high and linear response at working temperature 300 °C toward low and high ethanol concentrations with detection limit less than 1 ppm. Long term stability has been also investigated and sensor exhibits after one year, similar and reproducible responses.

Acute effects of alcohol on cardiac electrophysiology and arrhythmogenesis: Insights from multiscale in silico analyses

Acute excessive ethyl alcohol (ethanol) consumption alters cardiac electrophysiology and can evoke cardiac arrhythmias, e.g., in ‘holiday heart syndrome’. Ethanol acutely modulates numerous targets in cardiomyocytes, including ion channels, Ca2+-handling proteins and gap junctions. However, the mechanisms underlying ethanol-induced arrhythmogenesis remain incompletely understood and difficult to study experimentally due to the multiple electrophysiological targets involved and their potential interactions with preexisting electrophysiological or structural substrates. Here, we employed cellular- and tissue-level in-silico analyses to characterize the acute effects of ethanol on cardiac electrophysiology and arrhythmogenesis.Acute electrophysiological effects of ethanol were incorporated into human atrial and ventricular cardiomyocyte computer models: reduced INa, ICa,L, Ito, IKr and IKur, dual effects on IK1 and IK,ACh (inhibition at low and augmentation at high concentrations), and increased INCX and SR Ca2+ leak. Multiscale simulations in the absence or presence of preexistent atrial fibrillation or heart-failure-related remodeling demonstrated that low ethanol concentrations prolonged atrial action-potential duration (APD) without effects on ventricular APD. Conversely, high ethanol concentrations abbreviated atrial APD and prolonged ventricular APD. High ethanol concentrations promoted reentry in tissue simulations, but the extent of reentry promotion was dependent on the presence of altered intercellular coupling, and the degree, type, and pattern of fibrosis.Taken together, these data provide novel mechanistic insight into the potential proarrhythmic interactions between a preexisting substrate and acute changes in cardiac electrophysiology. In particular, acute ethanol exposure has concentration-dependent electrophysiological effects that differ between atria and ventricles, and between healthy and diseased hearts. Low concentrations of ethanol can have anti-fibrillatory effects in atria, whereas high concentrations promote the inducibility and maintenance of reentrant atrial and ventricular arrhythmias, supporting a role for limiting alcohol intake as part of cardiac arrhythmia management.