Alcohol Vapor Research Articles

WO3−x/WS2 Nanocomposites for Fast-Response Room Temperature Gas Sensing

Currently, semiconductor gas sensors are being actively studied and used in various fields, including ecology, industry, and medical diagnostics. One of the major challenges is to reduce their operating temperature to room temperature. To address this issue, sensor layers based on WO3−x/WS2 nanostructures synthesized by the hydrothermal method have been proposed. In this paper, the morphology of the material’s surface and its elemental composition were investigated, as well as the optical band gap. Additionally, changes in the resistance of the WO3−x/WS2 sensor layers under the influence of alcohol vapors at room temperature were analyzed. The results showed that the layers exhibited a significant response, with short response and recovery times. The achieved response value to 1000 ppm of isopropanol was 1.25, with a response time of 13 s and a recovery time of 12 s. The response to 1000 ppm of ethanol was 1.35, and the response and recovery times were 20 s. This indicates that these sensor layers have promising potential for various applications.

Effects of daridorexant on rest/wake activity patterns and drinking in adult rats exposed to chronic ethanol vapor in adolescence.

Disturbance in sleep and activity rhythms are significant health risks associated with alcohol use during adolescence. Many investigators support the theory of a reciprocal relationship between disrupted circadian rhythms, sleep patterns, and alcohol usage. However, in human studies it is difficult to disentangle other factors (i.e. lifestyle, psychiatric, genetic) when determining what is causal in the relationship between substance use and sleep/activity disruptions. To this end, we used an animal model of adolescent alcohol exposure whereby male and female Wistar rats are exposed to 5 weeks of intermittent alcohol vapor during adolescence (P22-P57). Five days after ethanol vapor rats were allowed to select to drink alcohol or water in a two-bottle choice procedure for a period of 5 hours, 4 days a week for 6 weeks. Activity data was collected using a "Fitbit-like" device during vapor exposure, during acute withdrawal, and after 3 weeks of protracted withdrawal. Significant changes in rest/wake activity and circadian measures were seen during 24-hour withdrawal and after 3 weeks of withdrawal. Four weeks following withdrawal, the effects of the dual orexin antagonist, Daridorexant, (DAX 30mg, 100mg, or vehicle control), on alcohol drinking and rest and activity rhythms were assessed over a 24h period. Both daridorexant doses led to changes in circadian measures and rest/wake activity patterns. These results showed that daridorexant reduced activity, but it did not improve rest quality as measured by the mean inactive episode duration and inactive fragmentation ratio. Additionally, we did not find a significant difference in drinking behavior in animals treated with the orexin antagonist. Thus, it appears that data from this animal model do not support the use of this drug to improve adolescent alcohol-induced sleep disturbance and/or to decrease alcohol drinking.

Harnessing Halogenated Zeolitic Imidazolate Frameworks for Alcohol Vapor Adsorption.

This study explores Zeolitic Imidazolate Frameworks (ZIFs) as promising materials for adsorbing alcohol vapors, one of the main contributors to air quality deterioration and adverse health effects. Indeed, this sub-class of Metal-Organic Frameworks (MOFs) offers a promising alternative to conventional adsorbents like zeolites and activated carbons for air purification. Specifically, this investigation focuses on ZIF-8_Br, a brominated version of ZIF-8_CH3, to evaluate its ability to capture aliphatic alcohols at lower partial pressures. The adsorption properties have been investigated using both experimental and computational methods combining Density Functional Theory and Grand Canonical Monte Carlo simulations. The Ideal Adsorbed Solution Theory (IAST) has been used to assess the material selectivity in the presence of binary equimolar alcohol mixtures. Compared to ZIF-8_CH3, the brominated analog has been shown to feature a higher affinity for alcohols, a property that could be advantageously exploited in environmental remediation or in the development of membranes for alcohol vapor sensors.

The The Gas-Sensitive Properties of Tin Dioxide Films

This study investigates the fabrication and performance of SnO2 thin films for gas sensing applications, utilizing a deposition method at 2 bar pressure and 8 ml/min flow rate. A multilayer structure was developed, comprising 14 layers, each with a thickness of 250 nm, optimized for sensitivity and stability. The gas sensor, featuring a film heater and sensitive elements doped with a 1% silicon additive, demonstrated a wide operational temperature range (20-370 °C). Characterization of resistance changes revealed significant hysteresis before isothermal annealing, with resistance values stabilizing after prolonged exposure to 370 °C. Post-annealing, the sensor exhibited three orders of magnitude higher resistance, indicating improved stability and electronic transport properties. Doping with a 1N AgNO3 solution significantly enhanced sensitivity to ammonia, with a detection threshold of 500 ppm, while sensitivity to alcohol vapors decreased, indicating selectivity. Experimental results confirm that local doping and thermal treatment effectively enhance the metrological characteristics of SnO2-based sensors, making them suitable for detecting toxic gases.

Deep Microfabrication of Silica Glass Using Atmospheric Gas-Phase Catalyst Etching for Sensing Applications

Deep microfabrication processes such as the Bosch process have dramatically improved the performance of Si-MEMS devices. In contrast to Si, SiO2 is suitable for optical analysis devices because of its high transparency over a wide range and chemical durability. In recent years, micro-total analysis systems using glass-type microfluidics or microwell arrays have attracted attention in the field of biotechnology. Anisotropic microstructures on silica glass substrates are generally fabricated via reactive ion etching (RIE). However, high-power ion energy is required to fabricate deep microstructures because of the high chemical and plasma durability of SiO2. Therefore, the fabrication of vertical deep microstructures on SiO2 has been a longstanding problem because a hard mask material is etched simultaneously during RIE. We focused on surface treatment with HF gas, which enables dry etching of SiO2 without using a plasma source1,2. The chemical reaction between HF gas and SiO2 can be expressed as follows:SiO2 + 4HF → SiF4 + 2H2O.However, the etching reaction of SiO2 by HF molecules is extremely slow1. Therefore, H2O or alcohol, which form hydrogen bonds with HF molecules, are added as a catalyst in the etching of SiO2 with HF gas2,3.This study proposed the deep microfabrication of SiO2 by HF gas etching using a photoresist as a catalyst that allows micro-scale patterning on the substrate4. The hydrophilic functional groups in the catalyst formed hydrogen bonds with the HF molecules at the interface with SiO2. Therefore, the etching reaction by HF gas occurs only at the interface between SiO2 and the catalyst. This selective etching reaction enables deep microfabrication on SiO2 without the use of a plasma source or hard mask materials. The microstructures fabricated via the HF gas-phase catalyst etching were characterized by high verticality and smooth sidewall surfaces, as shown in Fig.1. This simple microfabrication process could improve the sensing performance and the mass production of SiO2-based microfluidic devices and microwells.REFERENCES Habuka, H.; Otsuka, T. Reaction of Hydrogen Fluoride Gas at High Temperatures with Silicon Oxide Film and Silicon Surface. J. Appl. Phys., 1998, 37, 6123–6127.Holmes, P. J.; Snell, J. E. A Vapor Etching Technique for the Photolithography of Silicon Dioxide. Microelectronics and Reliability, 1966, 5, 337–341.Jang, W. I.; Choi, C.A.; Lee, M.L.; Jun, C.H.; Kim, Y.T. Fabrication of MEMS Devices by Using Anhydrous HF Gas-Phase Etching with Alcoholic Vapor. Micromech. Microeng., 2002, 12, 297–306.Sano, K.-H.; Ono, Y.; Tobinaga, R.; Imamura, Y.; Hayashi, Y.; Yanagitani, T. (in press). Atmospheric Gas-phase Catalyst Etching of SiO2 for Deep Microfabrication Using HF Gas and Patterned Photoresist. ACS Appl. Mater. Interfaces, Apr. 2024. Figure 1

Bottom-up designing nanostructured oxide libraries under a lab-on-chip paradigm towards a low-cost highly-selective E-nose

BackgroundThe multisensor concept has been developed as a powerful alternative to well-known gas-analytical instrumentation for applications where a fast but accurate and reliable assessment of the environment is required. The concept follows a biology-inspired approach where the selectivity towards various gases/odors is attained via pattern recognition of multisensory signal vectors. Herein, we discuss how to design a selective multisensor library based on various metal oxide nanostructures like a lab-on-chip using a simple but efficient bottom-up growth of materials over the multi-electrode chip under robust dc electrochemical protocols. ResultsIn addition to a conventional growth of oxide layers over the metal electrodes, we show that the fine nanowall-like oxide structures appear as a quasi-matrixed percolation film over the SiO2 substrate surface in the inter-electrode gaps to constitute a chemiresistive film. We have tested two directions while applying the technique to grow Co, Ni, Mn, and Zn oxides to develop on-chip sensor arrays of, (i) monoxide type employing the oxide films with gradual change of growth time, and (ii) multi-oxide type based on the four oxides. The materials were thoroughly characterized by electron microscopy, X-ray diffraction, thermogravimetric analysis, and X-ray photoelectron spectroscopy/mapping to prove the composition and structure. Among tested oxides, ZnO readily appears not only at the electric potential-targeted chip zone but also in other areas to dope the films for yielding heterojunctions with other oxides that enhances a variability of functional properties in the on-chip sensor array. The gas-sensing performance of the chips has been tested versus various chemically akin alcohol vapors at the sub- and low ppm range of concentrations in a mixture with air. SignificanceWe show that the grown oxide nanostructures exhibit a high-sensitive chemiresistive signal which allows one to build a multisensor vector signal, selective to the kind of alcohols, even at sub-ppm concentrations. Moreover, the multi-oxide library yields options for a superior selectivity under LDA metrics than the gradient-grown mono-oxide one due to the versatility of materials while the low-cost growth protocols remain to be the same in both cases. The delivered method to produce multisensor arrays allows one producing low-cost but efficient electronic nose units for numerous applications.

THE PREPARATION OF Al-DOPED ZnO THIN FILMS BY SPRAY PYROLYSIS TECHNIQUE FOR ALCOHOL VAPOR SENSOR

Thin films of ZnO and Al-doped ZnO are deposited on glass wafer substrates using a compressed sprayer system with Zn(CH3COO)2.2H2O and AlCl3 as precursors. The influence of Al doping concentration on the crystal phase and morphology of the samples is investigated by XRD and SEM, respectively. The results show that the films have been crystallized in the form of the wurtzite hexagonal phase of the ZnO lattice, and the addition of Al does not change the ZnO crystal structure. Despite this, SEM images show that added Al significantly affects the particle size of the samples. The particle size decreases and becomes more uniform as the Al concentration increases up to 7%. Further increasing the Al concentration causes the particles to agglomerate into clusters. The resistance measurements show that the sheet resistance of the films decreases in the presence of the Al dopant, providing evidence that Al has been successfully doped into the ZnO crystal lattice. An appropriate amount of Al dopant can improve the alcohol vapor sensitivity of the film. The ZnO film doped with 7% Al exhibits the best alcohol sensitivity.

Influence of Layer’s Annealing Temperature on Sensing Properties of Spin-Coated SBS Layer Exposed to Alcohol Vapor

QCM-based alcohol vapor sensors have been widely researched, and various materials have been deposited onto the sensor surface to serve as a functional layer. However, non-conductive polymers such as SBS as a functional layer for alcohol sensors are still minimally reported. In this study, the SBS was deposited on 1 side of the QCM using the spin coating technique. After deposition, the layer was annealed for 1 h. The annealing temperatures are 100, 150 and 200 °C. The concentrations of exposed alcohol vapor were 5, 10, 15, 20, 25, 50, 75 and 100 ppm. This study demonstrated that the SBS layer has the potential to be a functional layer of alcohol sensors. SBS 200 °C is an optimum functional layer for alcohol vapor sensors due to its high ∆f and sensitivity. Meanwhile, SBS 100 °C has poor ∆f and sensitivity. This is due to the morphology of 200 °C SBS, which consists of more valleys that perform as interaction sites for SBS and alcohol molecules. However, one of the limitations of SBS as a functional sensor layer for alcohol sensors is its low selectivity, which is a characteristic of rubbery polymers. HIGHLIGHTS The SBS layer annealed at higher temperatures has more valleys than the SBS layer annealed at low temperatures. The valleys in the morphology of the SBS layer act as interaction sites for alcohol molecules, where each site interacts with an alcohol molecule. It is based on the sensor response and proved by fitting the Langmuir model. The SBS layer annealed at 200 ᵒC has a high ∆f, sensitivity, and longer response time. The selectivity of SBS was relatively low, a characteristic of rubbery polymers. The interaction between SBS and methanol is physisorption. GRAPHICAL ABSTRACT

Benefits of exercise on cognitive impairment in alcohol use disorder following alcohol withdrawal.

Although most cognitive impairments induced by prolonged alcohol consumption tend to improve within the initial months of abstinence, there is evidence suggesting certain cognitive deficits may persist. This study aimed to investigate the impact of aerobic exercise on learning and memory in alcohol use disorder (AUD) mice following a period of abstinence from alcohol. We also sought to assess the levels of monoamine neurotransmitters in the hippocampus. To this end, we established an AUD mouse model through a two-bottle choice (sucrose fading mode and normal mode) and chronic intermittent alcohol vapor (combined with intraperitoneal injection) and randomly allocated mice into exercise groups to undergo treadmill training. Learning and memory abilities were assessed through the Morris water maze test and spontaneous activity was evaluated using the open field test. The levels of dopamine, norepinephrine, serotonin, and brain-derived neurotrophic factor in the hippocampus were quantified using enzyme-linked immunoassay (ELISA) kits. The findings reveal that after cessation of alcohol consumption, learning and memory abilities in AUD mice did not completely return to normal levels. The observed enhancement of cognitive functions in AUD mice through aerobic exercise may be attributed to restoring levels of monoamine neurotransmitters in the hippocampus, boosting brain-derived neurotrophic factor (BDNF) concentrations, and facilitating an increase in hippocampal mass. These results offer empirical evidence to support aerobic exercise as a viable therapeutic strategy to alleviate cognitive deficits associated with AUD.

Monitoring of meat quality and change-point detection by a sensor array and profiling of bacterial communities

BackgroundReal-time monitoring of food consumer quality remains challenging due to diverse bio-chemical processes taking place in the food matrices, and hence it requires accurate analytical methods. Thresholds to determine spoiled food are often difficult to set. The existing analytical methods are too complicated for rapid in situ screening of foodstuff. ResultsWe have studied the dynamics of meat spoilage by electronic nose (e-nose) for digitizing the smell associated with volatile spoilage markers of meat, comparing the results with changes in the microbiome composition of the spoiling meat samples. We apply the time series analysis to follow dynamic changes in the gas profile extracted from the e-nose responses and to identify the change-point window of the meat state. The obtained e-nose features correlate with changes in the microbiome composition such as increase in the proportion of Brochothrix and Pseudomonas spp. and disappearance of Mycoplasma spp., and with representative gas sensors towards hydrogen, ammonia, and alcohol vapors with R2 values of 0.98, 0.93, and 0.91, respectively. Integration of e-nose and computer vision into a single analytical panel improved the meat state identification accuracy up to 0.85, allowing for more reliable meat state assessment. SignificanceAccurate identification of the change-point in the meat state achieved by digitalizing volatile spoilage markers from the e-nose unit holds promises for application of smart miniaturized devices in food industry.

Sol-gel derived ZnO film as a gas sensor: Influence of UV processing versus a thermal annealing

While preparing oxide layers as gas sensors by a sol-gel approach, a high-temperature annealing makes a challenge to apply in numerous applications like flexible electronics with a heavy influence on the oxide microstructure. Therefore, its replacing by UV irradiation combined with a mild heating as “photo-annealing” paves the way to develop soft protocols when designing oxide-based gas sensors bearing a fine nanocrystallinity. Herein, we consider hierarchical sol-gel derived ZnO films which were a subject of conventional annealing and photoannealing to compare their gas-sensor performance when exposed to alcohol vapors. It is found that films obtained by photoannealing have an X-ray amorphous character, in contrast to ones being thermally annealed; although, the hierarchical organization of both samples revealed by SEM is almost identical. The DFTB modeling performed for ZnO crystal exposed to alcohol molecules and water has indicated the chemiresistive effect to be enhanced with a molecular weight of analytes. These observations were validated in experiment with sol-gel ZnO layers which exhibited an alcohol response in sub-ppm concentration range down to 10 ppb. To selectively compare the impact of various alcohols, we successfully applied a linear-discriminant analysis to the vector signal of the on-chip multisensor array.

Water Microdroplets Surrounded by Alcohol Vapor Cause Spontaneous Oxidation of Alcohols to Organic Peroxides.

Using real-time mass spectrometric (MS) monitoring, we demonstrate one-step, catalyst-free spontaneous oxidation of various alcohols (ROH) to key reactive intermediates for the formation of ROO- compounds on the surface of water microdroplets surrounded by alcohol vapor, carried out under ambient conditions. These organic peroxides (POs) can act as important secondary organic aerosols (SOA). We used hydrogen-deuterium exchange by spraying D2O instead of H2O to learn about the reaction mechanism, and the results demonstrate the crucial role of the water-air interface in microdroplet chemistry. We find that the formation of POs relies on electron transfer occurring at the microdroplet interface, which generates hydrogen atoms and hydroxyl radicals that lead to a cascade of radical reactions. This electron transfer is believed to be driven by two factors: (1) the emergence of a strong electrostatic potential on the microdroplet's surface; and (2) the partial solvation of ions at the interface. Mass spectra reveal that the formation of POs is dependent on the alcohol structure, with tertiary alcohols showing a higher tendency to form organic peroxides than secondary alcohols, which in turn are more reactive than primary alcohols.

Effects of cannabidiol, with and without ∆9-tetrahydrocannabinol, on anxiety-like behavior following alcohol withdrawal in mice.

Alcohol use disorder (AUD) is commonly associated with anxiety disorders and enhanced stress-sensitivity; symptoms that can worsen during withdrawal to perpetuate continued alcohol use. Alcohol increases neuroimmune activity in the brain. Our recent evidence indicates that alcohol directly modulates neuroimmune function in the central amygdala (CeA), a key brain region regulating anxiety and alcohol intake, to alter neurotransmitter signaling. We hypothesized that cannabinoids, such as cannabidiol (CBD) and ∆9-tetrahydrocannabinol (THC), which are thought to reduce neuroinflammation and anxiety, may have potential utility to alleviate alcohol withdrawal-induced stress-sensitivity and anxiety-like behaviors via modulation of CeA neuroimmune function. We tested the effects of CBD and CBD:THC (3:1 ratio) on anxiety-like behaviors and neuroimmune function in the CeA of mice undergoing acute (4-h) and short-term (24-h) withdrawal from chronic intermittent alcohol vapor exposure (CIE). We further examined the impact of CBD and CBD:THC on alcohol withdrawal behaviors in the presence of an additional stressor. We found that CBD and 3:1 CBD:THC increased anxiety-like behaviors at 4-h withdrawal. At 24-h withdrawal, CBD alone reduced anxiety-like behaviors while CBD:THC had mixed effects, showing increased center time indicating reduced anxiety-like behaviors, but increased immobility time that may indicate increased anxiety-like behaviors. These mixed effects may be due to altered metabolism of CBD and THC during alcohol withdrawal. Immunohistochemical analysis showed decreased S100β and Iba1 cell counts in the CeA at 4-h withdrawal, but not at 24-h withdrawal, with CBD and CBD:THC reversing alcohol withdrawal effects.. These results suggest that the use of cannabinoids during alcohol withdrawal may lead to exacerbated anxiety depending on timing of use, which may be related to neuroimmune cell function in the CeA.

Autocombustion Route Derived Zinc Ferrite Nanoparticles as Chemiresistive Sensor for Detection of Alcohol Vapors.

Prolonged exposure to alcohol vapors can have detrimental effects on human health, potentially leading to eye irritation, dizziness, and in some cases, damage to the nervous system. The present article aims to provide a comprehensive understanding on the synthesis and characterization of zinc ferrite (ZnFe2O4) nanoparticles, as well as their interactions with a range of alcohol vapors, including methanol, ethanol, n-propanol, and isopropanol. These alcohols differ in their molecular weight, boiling points, diffusivity, and other properties. The study reveals the semiconducting ZnFe2O4 nanoparticulate sensor's capability for reversible, repeatable, and sensitive detection of alcohol vapors. The sensor exhibits the highest response to ethanol within operating temperature range (225-300 °C). An attempt is made to establish a correlation between the properties of the target analytes and the observed sensing signals. Additionally, the response conductance transients of ZnFe2O4 under the exposure to the studied alcohol vapors are modeled based on the Langmuir-Hinshelwood adsorption mechanism. The characteristic time constants obtained from this modeling are justified with respect to the properties of the analytes.

Synthesis, crystal structures, and alcohol vapor adsorption properties of Cd(II) and Cu(II) complexes based on a salen-type Schiff base

A salen-type Schiff base ligand (H4L) was designed and synthesized from the condensation reaction. Four complexes, formulated as {[Cd(H5L+)Cl2(μ2 − Cl)]·2CH3OH}n (1), {[Cd(H4L)Br2]·H2O}n (2), {[Cd2(H4L)2I4]·CH3OH}n (3), and [Cu3(L4-)(μ3 − Ac)2]·CH3OH·H2O (4) were synthesized and characterized by single-crystal X-ray diffraction. Complex 1 exists as a 2D sheet structure and each Cd(II) ion in the complex is six-coordinated with an octahedral geometry. Both complexes 2 and 3 exist as 1D zig-zag structures and each Cd(II) ion in the two complexes is five-coordinated with a trigonal bipyramidal geometry. Complex 4 exists as a centrosymmetric trinuclear structure, in which two Cu(II) ions are five-coordinated with a square pyramidal geometry and the other Cu(II) ion is six-coordinated with an octahedral geometry. The structural differences are attributed to coordination ability of the coordination sites and coordination configurations of the metal ions. Furthermore, alcohol vapor adsorption measurements showed that all the synthesized complexes exhibited good adsorption capacities toward methanol vapor.

Vapor and Light Responsive Biocompatible Soft Actuator.

Bioinspired smart polymeric materials that undergo three-dimensional shape deformation in response to specific stimuli have gained significant attention in the field of soft robotics and intelligent devices. Despite the substantial advancements in soft robotics, there is a growing demand for the design of multistimuli-responsive soft actuators using a single layer of material due to its reduced complexity and ease of manufacturing and durability. Here, we report the actuation characteristics of a single-layer, dual-responsive soft actuator that overcomes the commonly encountered delamination issues often associated with bilayer systems by incorporating PEDOT:PSS with cassava starch. This soft actuator exhibits deformations in response to various solvent vapors, such as water, alcohol, and acetone. Remarkably, it demonstrates opposite deformations upon exposure to water and alcohol vapors. Additionally, the actuator responds to light triggers and folds upon exposure to sunlight and infrared light. The degree of folding can be precisely controlled by adjusting the intensity of the light source. Furthermore, the periodic geometric patterns imposed on the surface of the actuator provide an additional handle to control the bending axis. For proof of concept, we leverage the actuation capabilities of our actuator to showcase a range of potential applications, including its usage in wearable textiles, crawler robots, smart curtains, push-and-pull machines, and smart lifts.

LY2444296, a κ-opioid receptor antagonist, selectively reduces alcohol drinking in male and female Wistar rats with a history of alcohol dependence

Alcohol use disorder (AUD) remains a major public health concern. The dynorphin (DYN)/κ-opioid receptor (KOP) system is involved in actions of alcohol, particularly its withdrawal-associated negative affective states. This study tested the ability of LY2444296, a selective, short-acting, KOP antagonist, to decrease alcohol self-administration in dependent male and female Wistar rats at 8 h abstinence. Animals were trained to orally self-administer 10% alcohol (30 min/day for 21 sessions) and were made dependent via chronic intermittent alcohol vapor exposure for 6 weeks or exposed to air (nondependent). After 6 weeks, the effect of LY2444296 (0, 3, and 10 mg/kg, p.o.) was tested on alcohol self-administration at 8 h of abstinence. A separate cohort of rats was prepared in parallel, and their somatic withdrawal signs and alcohol self-administration were measured after LY2444296 administration at 8 h, 2 weeks, and 4 weeks abstinence. LY2444296 at 3 and 10 mg/kg significantly reduced physical signs of withdrawal in dependent rats at 8 h abstinence, only. Furthermore, 3 and 10 mg/kg selectively decreased alcohol self-administration in dependent rats at only 8 h abstinence. These results highlight the DYN/KOP system in actions of alcohol during acute abstinence, suggesting KOP antagonism could be beneficial for mitigating acute withdrawal signs and, in turn, significantly reduce excessive alcohol consumption associated with AUD.

Modeling the mechanical response of microelectromechanical system (MEMS)-based sensors to volatile alcohol vapors: A finite element analysis

The development of microelectromechanical system-based sensors, such as microcantilever sensors, has garnered considerable interest across various fields. Notably, there is a significant focus on the detection of volatile alcohol vapors, which holds promise in mitigating breath-related illnesses. This study employed finite element analysis to simulate the deflection of a silica-based microcantilever coated with polymethyl methacrylate in response to different volatile alcohol vapors (VAVs), such as methanol, ethanol, and isopropanol. A Multiphysics framework was used to analyze the time-dependent response of a microcantilever to different concentrations of VAVs incorporating fluid–structure interaction. This complex model integrated the aspects of laminar flow, solid mechanics, and transport of dilute species. Significant agreement has been achieved between finite element analysis-simulated results and the experimental findings that we had previously documented. This alignment revealed consistent trends, with methanol exhibiting higher levels than ethanol, followed by isopropanol, further validating the robustness and reliability of the sensor system in VAV detection.

Nutritional ketosis as treatment for alcohol withdrawal symptoms in female C57BL/6J mice

Upon both acute and prolonged alcohol intake, the brain undergoes a metabolic shift associated with increased acetate metabolism and reduced glucose metabolism, which persists during abstinence, putatively leading to energy depletion in the brain. This study evaluates the efficacy of ketogenic treatments to rescue psychiatric and neurochemical alterations during long-term alcohol withdrawal. Female mice were intermittently exposed to alcohol vapor or air for three weeks, during which mice were introduced to either a ketogenic diet (KD), control diet supplemented with ketone ester (KE) or remained on control diet (CD). Withdrawal symptoms were assessed over a period of four weeks followed by re-exposure using several behavioral and biochemical tests. Alcohol-exposed mice fed CD displayed long-lasting depressive-like symptoms measured by saccharin preference and tail suspension, as well as decreased norepinephrine levels and serotonin turnover in the hippocampus. Both KD and KE rescued anhedonia for up to three weeks of abstinence. KD mice showed higher latency to first immobility in the tail suspension test, as well as lower plasma cholesterol levels. Our findings show promising effects of nutritional ketosis in ameliorating alcohol withdrawal symptoms in mice. KD seemed to better rescue these symptoms compared to KE.

Mechanisms of methanol detection in graphene oxide and conductive polymer active layers for gas sensing devices

The admixture of PEDOT:PSS with Graphene Oxide (GO) in precise proportions achieves a substantial reduction in electrical resistivity, thereby augmenting its suitability as an electrode in organic devices. This study explores the electrical and morphological attributes of commercial PEDOT:PSS and chemically synthesized aqueous PEDOT ink when both are combined with GO. The investigation extends to the application of these conductive inks as active layers in flexible methanol sensing devices. Notably, a resistivity minimum is observed in the case of GO:PEDOT:PSS 78%, while the highest response to methanol is attained with GO:PEDOT:PSS 68%. To establish a theoretical underpinning for these findings, and to understand the interaction between gas/vapors with nanostructured materials, a model rooted in Kirchhoff’s Circuit approach is developed, with the aim of elucidating the factors behind the resistivity minimum and response maximum at distinct specific mass ratios between PEDOT and GO. Calculating the equivalent resistivity and response of the systems, the positions of minimum and maximum points are in agreement with the experimental data. Furthermore, the influence of PSS in the samples is examined, unveiling diverse interaction mechanisms between methanol molecules and the active layer, resulting in varying signals during the exposure to alcoholic vapor. The theoretical model is subsequently applied to these systems, demonstrating qualitative and quantitative agreement with the experimental results.