Rationale: Hydrogen peroxide (H sub(2)O sub(2)) is the co-substrate used by catalase to metabolize ethanol to acetaldehyde in the brain. This centrally formed acetaldehyde has been involved in ...several ethanol-related behaviors. Objectives: The present research evaluated the effect of the H sub(2)O sub(2) scavenger, alpha lipoic acid (LA), on the acquisition and reconditioning of ethanol-induced conditioned place preference (CPP). Methods: Mice received pairings of a distinctive floor stimulus (CS+) associated with intraperitoneal injections of ethanol (2.5 g/kg). On alternate days, animals received pairings of a different floor stimulus (CS-) associated with saline injections. A different group of animals received pairings with the (CS-) associated with saline injections, and on alternate days they received LA (100 mg/kg) injected 30 min prior to ethanol (2.5 g/kg) administration paired with the (CS+). A preference test assessed the effect of LA on the acquisition of ethanol-induced CPP. A similar procedure was followed to study the effect of LA on the acquisition of cocaine- and morphine-induced CPP. A separate experiment evaluated the effect of LA on the reconditioning of ethanol-induced CPP. In addition, we investigated the consequence of LA administration on central H sub(2)O sub(2) levels. Results: LA selectively blocked the acquisition of ethanol-induced CPP. Moreover, this compound impaired the reconditioning of ethanol-induced CPP. Additionally, we found that LA diminished H sub(2)O sub(2) levels in the brain. Conclusions: These data suggest that a decline in H sub(2)O sub(2) availability by LA might impede the formation of brain ethanol-derived acetaldehyde by catalase, which results in an impairment of the rewarding properties of ethanol.
The introduction of drinking water disinfection greatly reduced waterborne diseases. However, the reaction between disinfectants and natural organic matter in the source water leads to an unintended ...consequence, the formation of drinking water disinfection byproducts (DBPs). The haloacetaldehydes (HALs) are the third largest group by weight of identified DBPs in drinking water. The primary objective of this study was to analyze the occurrence and comparative toxicity of the emerging HAL DBPs. A new HAL DBP, iodoacetaldehyde (IAL) was identified. This study provided the first systematic, quantitative comparison of HAL toxicity in Chinese hamster ovary cells. The rank order of HAL cytotoxicity is tribromoacetaldehyde (TBAL) ≈ chloroacetaldehyde (CAL) > dibromoacetaldehyde (DBAL) ≈ bromochloroacetaldehyde (BCAL) ≈ dibromochloroacetaldehyde (DBCAL) > IAL > bromoacetaldehyde (BAL) ≈ bromodichloroacetaldehyde (BDCAL) > dichloroacetaldehyde (DCAL) > trichloroacetaldehyde (TCAL). The HALs were highly cytotoxic compared to other DBP chemical classes. The rank order of HAL genotoxicity is DBAL > CAL ≈ DBCAL > TBAL ≈ BAL > BDCAL > BCAL ≈ DCAL > IAL. TCAL was not genotoxic. Because of their toxicity and abundance, further research is needed to investigate their mode of action to protect the public health and the environment.
In this work, the adsorption and photodegradation of acetaldehyde and ethylene on TiO.sub.2 nanoparticles (NPs) with dominant {001} facets were studied. Additionally, the first principle calculation ...was used to complement the experimental results. TiO.sub.2 NPs were synthesized by using a hydrothermal method. The experimental results indicated that adsorption amount of acetaldehyde on TiO.sub.2 {001} facets is higher than ethylene, with the initial concentration as 500 ± 10 ppm. Photodegradation efficiency of 88% was achieved for acetaldehyde in contrast to 17% for ethylene at flow rate of 10 sccm. The first principle calculations show that the adsorption energy (E.sub.ads) for acetaldehyde is 0.603 eV and that of ethylene is 0.251 eV. This study is imperative for understanding the adsorption and photodegradation process of acetaldehyde and ethylene, two typical VOCs, and helpful to design the photocatalysts with high efficiency.
In this work, the adsorption and photodegradation of acetaldehyde and ethylene on TiO.sub.2 nanoparticles (NPs) with dominant {001} facets were studied. Additionally, the first principle calculation ...was used to complement the experimental results. TiO.sub.2 NPs were synthesized by using a hydrothermal method. The experimental results indicated that adsorption amount of acetaldehyde on TiO.sub.2 {001} facets is higher than ethylene, with the initial concentration as 500 ± 10 ppm. Photodegradation efficiency of 88% was achieved for acetaldehyde in contrast to 17% for ethylene at flow rate of 10 sccm. The first principle calculations show that the adsorption energy (E.sub.ads) for acetaldehyde is 0.603 eV and that of ethylene is 0.251 eV. This study is imperative for understanding the adsorption and photodegradation process of acetaldehyde and ethylene, two typical VOCs, and helpful to design the photocatalysts with high efficiency. Graphical
This study reports a spatiotemporal characterization of formaldehyde and acetaldehyde in the summer and winter of 2017 in the urban area of Shiraz, Iran. Sampling was fulfilled according to EPA ...Method TO-11 A. The inverse distance weighting (IDW) procedure was used for spatial mapping. Monte Carlo simulations were conducted to evaluate carcinogenic and non-cancer risk owing to formaldehyde and acetaldehyde exposure in 11 age groups. The average concentrations of formaldehyde/acetaldehyde in the summer and winter were 15.07/8.40 μg m−3 and 8.57/3.52 μg m−3, respectively. The formaldehyde to acetaldehyde ratios in the summer and winter were 1.80 and 2.43, respectively. The main sources of formaldehyde and acetaldehyde were photochemical generation, vehicular traffic, and biogenic emissions (e.g., coniferous and deciduous trees). The mean inhalation lifetime cancer risk (LTCR) values according to the Integrated Risk Information System (IRIS) for formaldehyde and acetaldehyde in summer and winter ranged between 7.55 × 10−6 and 9.25 × 10−5, which exceed the recommended value by US EPA. The average LTCR according to the Office of Environmental Health Hazard Assessment (OEHHA) for formaldehyde and acetaldehyde in summer and winter were between 4.82 × 10−6 and 2.58 × 10−4, which exceeds recommended values for five different age groups (Birth to <1, 1 to <2, 2 to <3, 3 to <6, and 6 to <11 years). Hazard quotients (HQs) of formaldehyde ranged between 0.04 and 4.18 for both seasons, while the HQs for acetaldehyde were limited between 0.42 and 0.97.
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•FA:AA ratios in the summer and winter were 1.80 and 2.43, respectively.•Sources of FA and AA were photochemical generation and vehicular traffic.•LTCR for FA and AA in summer and winter were between 4.82 × 10−6 and 2.58 × 10−4.•Hazard quotients (HQs) for FA ranged between 0.04 and 4.18 for both seasons.•HQs for AA were limited between 0.42 and 0.97 for both seasons.
The atmospheric pressure solvothermal (APS) synthesis of nanocrystalline SnOsub.2 (average size of coherent scattering regions (CSR)-7.5 ± 0.6 nm) using tin acetylacetonate as a precursor was ...studied. The resulting nanopowder was used as a functional ink component in microextrusion printing of a tin dioxide thick film on the surface of a Pt/Alsub.2Osub.3/Pt chip. Synchronous thermal analysis shows that the resulting semiproduct is transformed completely into tin dioxide nanopowder at 400 °C within 1 h. The SnOsub.2 powder and the resulting film were shown to have a cassiterite-type structure according to X-ray diffraction analysis, and IR spectroscopy was used to establish the set of functional groups in the material composition. The microstructural features of the tin dioxide powder were analyzed using scanning (SEM) and transmission (TEM) electron microscopy: the average size of the oxide powder particles was 8.2 ± 0.7 nm. Various atomic force microscopy (AFM) techniques were employed to investigate the topography of the oxide film and to build maps of surface capacitance and potential distribution. The temperature dependence of the electrical conductivity of the printed SnOsub.2 film was studied using impedance spectroscopy. The chemosensory properties of the formed material when detecting Hsub.2, CO, NHsub.3, Csub.6Hsub.6, Csub.3Hsub.6O and Csub.2Hsub.5OH, including at varying humidity, were also examined. It was demonstrated that the obtained SnOsub.2 film has an increased sensitivity (the sensory response value was 1.4-63.5) and selectivity for detection of 4-100 ppm Csub.2Hsub.5OH at an operating temperature of 200 °C.
Biomass derived glycolaldehyde was employed as C1 building block for the N-formylation of secondary amines using air as oxidant. The reaction is atom economic, highly selective and proceeds under ...catalyst free conditions. This strategy can be used for the synthesis of cyclic and acyclic formylamines, including DMF. Mechanistic studies suggest a radical oxidation pathway.
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