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The Journal of Chemical Physics Jun 2024Acetaldehyde is a very relevant atmospheric species whose photodissociation has been extensively studied in the first absorption band both experimentally and...
Acetaldehyde is a very relevant atmospheric species whose photodissociation has been extensively studied in the first absorption band both experimentally and theoretically. Very few works have been reported on acetaldehyde photodissociation at higher excitation energies. In this work, the photodissociation dynamics of acetaldehyde is investigated by means of high-level multireference configuration interaction ab initio calculations. Five different fragmentation pathways of acetaldehyde are explored by calculating the potential-energy curves of the ground and several excited electronic states along the corresponding dissociating bond distances. The excitation energy range covered in the study is up to 10 eV, nearly the ionization energy of acetaldehyde. We intend to rationalize the available experimental results and, in particular, to elucidate why some of the studied fragmentation pathways are experimentally observed in the different excitation energy regions and some others are not. Based on the shape of the calculated potential curves, we are able to explain the main findings of the available experiments, also suggesting possible dynamical dissociation mechanisms in the different energy regions. Thus, the reported potential curves are envisioned as a useful tool to interpret the currently available experiments as well as future ones on acetaldehyde photodissociation at excitation wavelengths in the range studied here.
PubMed: 38874103
DOI: 10.1063/5.0207362 -
Journal of Agricultural and Food... Jun 2024Golden apple snail (), a major alien invasive organism in China, affects food production and poses a threat to human health. Metaldehyde is a highly effective, commonly...
Golden apple snail (), a major alien invasive organism in China, affects food production and poses a threat to human health. Metaldehyde is a highly effective, commonly used snail killer with low toxicity. Virulence determination, tissue section, iTRAQ and RNA interference were used to systematically study the toxicity of metaldehyde on . The molluscicidal activity tests showed that metaldehyde exhibits strong toxicity against . Physiological and biochemical data indicate that metaldehyde can cause damage to the gills, liver, pancreas, and kidneys of snails, also reduce the oxygen consumption rate and ammonia excretion rate of golden apple snails, and cause neurological diseases. The proteome of the gill region of the golden apple snail after exposure to metaldehyde was analyzed by using iTRAQ technology. A total of 360 differential proteins were identified, and four target proteins were screened, namely, alpha-protein kinase 1 (ALPK1), cubilin (CUBN), sodium- and chloride-dependent GABA transporter 2 (GAT2), and acetylcholinesterase (AChE). RNAi was used to target the four proteins. After the ALPK1 and CUBN protein genes were interfered with by metaldehyde treatment, it was found that the mortality rate of the golden apple snail significantly increased. However, interference of GAT2 and AChE protein genes by metaldehyde led to no significant change in the mortality rates of the snails. The histopathological observation of the gill showed that the rate of cilia shedding in the gill decreased after the interference of ALPK1 and CUBN protein genes.
Topics: Animals; Snails; Molluscacides; Acetaldehyde; Gills; Acetylcholinesterase; China
PubMed: 38869049
DOI: 10.1021/acs.jafc.3c06405 -
The Journal of Physical Chemistry. A Jun 2024Criegee intermediates exert a crucial influence on atmospheric chemistry, functioning as powerful oxidants that facilitate the degradation of pollutants, and...
Criegee intermediates exert a crucial influence on atmospheric chemistry, functioning as powerful oxidants that facilitate the degradation of pollutants, and understanding their reaction kinetics is essential for accurate atmospheric modeling. In this study, the kinetics of CHOO and -CHCHOO reactions with acetaldehyde (CHCHO) were investigated using a flash photolysis reaction tube coupled with the OH laser-induced fluorescence (LIF) method. The experimental results indicate that the reaction of -CHCHOO with CHCHO is independent of pressure in the range of 5-50 Torr when using Ar as the bath gas. However, the rate coefficient for the reaction between CHOO and CHCHO at 5.5 Torr was found to be lower compared to the near-constant values observed between 10 and 100 Torr. Furthermore, the reaction of -CHCHOO with CHCHO demonstrated positive temperature dependence from 283 to 330 K, with a rate coefficient of (2.11 ± 0.45) × 10 cm molecule s at 298 K. The activation energy and pre-exponential factor derived from the Arrhenius plot for this reaction were determined to be 2.32 ± 0.49 kcal mol and (1.66 ± 0.61) × 10 cm molecule s, respectively. In comparison, the reaction of CHOO with CHCHO exhibited negative temperature dependence, with a rate coefficient of (2.16 ± 0.39) × 10 cm molecule s at 100 Torr and 298 K and an activation energy and a pre-exponential factor of -1.73 ± 0.31 kcal mol and (1.15 ± 0.21) × 10 cm molecule s, respectively, over the temperature range of 280-333 K.
PubMed: 38868987
DOI: 10.1021/acs.jpca.4c01374 -
Minerva Medica Jun 2024Alcohol consumption can cause, beyond addiction, roughly 200 different diseases and at least fourteen types of cancer. In 2016 the WHO estimated that 29% of...
Alcohol consumption can cause, beyond addiction, roughly 200 different diseases and at least fourteen types of cancer. In 2016 the WHO estimated that 29% of alcohol-related deaths were mainly due to oncological diseases, liver cirrhosis (20%), and cardiovascular disorders (19%). The aim of this review was to focus on the absorption and metabolism of ethanol and discuss the main conditions caused by alcohol consumption (i.e., liver and cardiovascular diseases, and tumors). This narrative review is based on a detailed analysis of the scientific literature published before January 31, 2024 (PubMed, Web of Science, Scopus, Google Scholar). Approximately 90% of the absorbed alcohol reaches the liver where it is metabolized to acetaldehyde, a highly reactive and toxic compound. The excessive use of alcohol causes damage to several organs and systems, mainly the liver (e.g., steatosis, steato-hepatitis, fibrosis, and cirrhosis), cardiovascular system (cardiomyopathy, arrythmias, arterial hypertension, and stroke), and significantly contribute to the onset of neoplastic lesions to various organs including the esophagus, liver and breast. Even moderate drinking appears not to reduce mortality risk. Alcohol intake is one of the main risk factors for several pathological conditions and social problems, thus drastically impacting on public health. Proper awareness of the high risk related to alcohol consumption is of crucial importance to reduce the harm to public health.
PubMed: 38867598
DOI: 10.23736/S0026-4806.24.09355-8 -
Biological & Pharmaceutical Bulletin Jun 2024Ethanol (alcohol) is a risk factor that contributes to non-communicable diseases. Chronic abuse of ethanol is toxic to both the heart and overall health, and even...
Epigallocatechin-3-gallate alleviates ethanol-induced endothelia cells injury partly through alteration of NF-κB translocation and activation of the Nrf2 signaling pathway.
Ethanol (alcohol) is a risk factor that contributes to non-communicable diseases. Chronic abuse of ethanol is toxic to both the heart and overall health, and even results in death. Ethanol and its byproduct acetaldehyde can harm the cardiovascular system by impairing mitochondrial function, causing oxidative damage, and reducing contractile proteins. Endothelial cells are essential components of the cardiovascular system, are highly susceptible to ethanol, either through direct or indirect exposure. Thus, protection against endothelial injury is of great importance for persons who chronic abuse of ethanol. In this study, an in vitro model of endothelial injury was created using ethanol. The findings revealed that a concentration of 20.0 mM of ethanol reduced cell viability and Bcl-2 expression, while increasing cell apoptosis, intracellular ROS levels, mitochondrial depolarization, and the expression of Bax and cleaved-caspase-3 in endothelial cells. Further study showed that ethanol promoted nuclear translocation of NF-κB, increased the secretion of TNF-α,IL-1β, IL-6 in the culture medium, and inhibited Nrf2 signaling pathway. The aforementioned findings suggest that ethanol has a harmful impact on endothelial cells. Nevertheless, the application of epigallocatechin-3-gallate (EGCG) to the cells can effectively mitigate the detrimental effects of ethanol on endothelial cells. In conclusion, EGCG alleviates ethanol-induced endothelial injury partly through alteration of NF-κB translocation and activation of the Nrf2 signaling pathway. Therefore, EGCG holds great potential in safeguarding individuals who chronically abuse ethanol from endothelial dysfunction.
PubMed: 38866477
DOI: 10.1248/bpb.b23-00773 -
Journal of Food Science Jun 2024Polyvinylpolypyrrolidone (PVPP) is a synthetic, insoluble polymer that can be added to white wines to improve the chemical stability of the final product by...
Polyvinylpolypyrrolidone (PVPP) is a synthetic, insoluble polymer that can be added to white wines to improve the chemical stability of the final product by precipitating unstable low molecular weight phenolic compounds responsible for visual defects and undesirable flavor characteristics (e.g., excessive bitterness and/or astringency). The objective of this study was to characterize the effects of PVPP on the quality characteristics of Viognier wine when added pre- or post-fermentation as compared to an untreated control wine. Both PVPP-treated wines contained significantly lower concentrations of monomeric phenolics and browning pigments than the control wine (p ≤ 0.05). The addition of PVPP prior to fermentation conferred protection against oxidation of the wine as measured by acetaldehyde concentration (p ≤ 0.05). Analysis of the volatile aroma profile of each wine by headspace solid phase microextraction gas chromatographymass spectrometry (HS-SPME-GC-MS) revealed that the overarching aroma profiles of the PVPP-treated wines were significantly different from the control wine, but there was no difference between wines treated with PVPP pre-fermentation versus those treated post-fermentation. Specifically, statistically significant differences were observed in 9 of the 22 quantified aroma compounds, including those notably associated with the "stone fruit" aroma of Viognier. A negative correlation was identified between aroma compound concentration removal and the hydrophobicity of each compound, suggesting that the observed differences in aroma may be due to adsorption of aroma compounds by PVPP. The findings from this study present risks and benefits to wine quality upon treatment with PVPP at commercially recommended levels, and provide potentially valuable information for industrial wine producers.
PubMed: 38858776
DOI: 10.1111/1750-3841.17141 -
ChemSusChem Jun 2024We report the catalytic synthesis of 3-hydroxy-2-butanon (acetoin) from acetaldehyde as a key step in the synthesis of C4-molecules from ethanol. Facile C-C-bond...
We report the catalytic synthesis of 3-hydroxy-2-butanon (acetoin) from acetaldehyde as a key step in the synthesis of C4-molecules from ethanol. Facile C-C-bond formation at the α-carbon of the C2 building block is achieved using an N-heterocyclic carbene (NHC) catalyst. The immobilization of the catalyst on a Merrifield's peptide resin and its spectroscopic characterisation using solid-state Nuclear Magnetic Resonance (NMR) is described herein. The immobilization of the NHC catalyst allows for process intensification steps and the reported catalytic system was subjected to batch recycling as well as continuous flow experiments. The robustness of the catalytic system was shown over a maximum of 10 h time-on-stream. Overall, high selectivity S > 90% was observed. The observed deactivation of the catalyst with increasing time-on-stream is explained by ex-situ1H solution-state, as well as 13C and 15N solid-state NMR spectra allowing us to develop a deeper understanding of the underlying decomposition mechanism of the catalyst.
PubMed: 38853691
DOI: 10.1002/cssc.202400647 -
Animal Models and Experimental Medicine Jun 2024This review delves into the detrimental impact of alcohol consumption on internal organs and reproductive health, elucidating the underlying mechanisms involving the... (Review)
Review
This review delves into the detrimental impact of alcohol consumption on internal organs and reproductive health, elucidating the underlying mechanisms involving the Toll-like receptor 4 (TLR4)/Nuclear factor kappa light chain enhancer of activated B cells (NF-kB) pathway and the Cytochrome P450 2E1 (CYP2E1)/reactive oxygen species (ROS)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathways. The TLR4/NF-kB pathway, crucial for inflammatory and immune responses, triggers the production of pro-inflammatory agents and type-1 interferon, disrupting the balance between inflammatory and antioxidant responses when tissues are chronically exposed to alcohol. Alcohol-induced dysbiosis in gut microbes heightens gut wall permeability to pathogen-associated molecular patterns (PAMPs), leading to liver cell infection and subsequent inflammation. Concurrently, CYP2E1-mediated alcohol metabolism generates ROS, causing oxidative stress and damaging cells, lipids, proteins, and deoxyribonucleic acid (DNA). To counteract this inflammatory imbalance, Nrf2 regulates gene expression, inhibiting inflammatory progression and promoting antioxidant responses. Excessive alcohol intake results in elevated liver enzymes (ADH, CYP2E1, and catalase), ROS, NADH, acetaldehyde, and acetate, leading to damage in vital organs such as the heart, brain, and lungs. Moreover, alcohol negatively affects reproductive health by inhibiting the hypothalamic-pituitary-gonadal axis, causing infertility in both men and women. These findings underscore the profound health concerns associated with alcohol-induced damage, emphasizing the need for public awareness regarding the intricate interplay between immune responses and the multi-organ impacts of alcohol consumption.
PubMed: 38853347
DOI: 10.1002/ame2.12436 -
European Archives of Psychiatry and... Jun 2024Ethanol is metabolized by alcohol dehydrogenase to acetaldehyde and induces cytochrome P450 2E1 (CYP2E1), which generates reactive oxygen species that cause inflammatory...
Ethanol is metabolized by alcohol dehydrogenase to acetaldehyde and induces cytochrome P450 2E1 (CYP2E1), which generates reactive oxygen species that cause inflammatory liver damage. Clomethiazole, a drug approved for alcohol withdrawal treatment (AWT) in some European countries, inhibits CYP2E1. We hypothesized that clomethiazole would lead to a faster reduction in oxidative stress, inflammatory cytokines, and liver enzymes compared to diazepam treatment. We analysed respective biomarkers in 50 patients undergoing AWT and 25 healthy individuals but found no statistical difference between the two medication groups over 3-5 days. Hence, our hypothesis was not confirmed during this observation period.
PubMed: 38851655
DOI: 10.1007/s00406-024-01835-7 -
European Heart Journal Jun 2024Alcohol-induced cardiomyopathy (AC) is an acquired form of dilated cardiomyopathy (DCM) caused by prolonged and heavy alcohol intake in the absence of other causes. The...
Alcohol-induced cardiomyopathy (AC) is an acquired form of dilated cardiomyopathy (DCM) caused by prolonged and heavy alcohol intake in the absence of other causes. The amount of alcohol required to produce AC is generally considered as >80 g/day over 5 years, but there is still some controversy regarding this definition. This review on AC focuses on pathogenesis, which involves different mechanisms. Firstly, the direct toxic effect of ethanol promotes oxidative stress in the myocardium and activation of the renin-angiotensin system. Moreover, acetaldehyde, the best-studied metabolite of alcohol, can contribute to myocardial damage impairing actin-myosin interaction and producing mitochondrial dysfunction. Genetic factors are also involved in the pathogenesis of AC, with DCM-causing genetic variants in patients with AC, especially titin-truncating variants. These findings support a double-hit hypothesis in AC, combining genetics and environmental factors. The synergistic effect of alcohol with concomitant conditions such as hypertension or liver cirrhosis can be another contributing factor leading to AC. There are no specific cardiac signs and symptoms in AC as compared with other forms of DCM. However, natural history of AC differs from DCM and relies directly on alcohol withdrawal, as left ventricular ejection fraction recovery in abstainers is associated with an excellent prognosis. Thus, abstinence from alcohol is the most crucial step in treating AC, and specific therapies are available for this purpose. Otherwise, AC should be treated according to current guidelines of heart failure with reduced ejection fraction. Targeted therapies based on AC pathogenesis are currently being developed and could potentially improve AC treatment in the future.
PubMed: 38848133
DOI: 10.1093/eurheartj/ehae362