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Aqueous-phase chemistry of glyoxal (GL) with reduced nitrogen compounds (RNCs) plays a significant source of secondary brown carbon (SBrC), which is one of the largest uncertainties in climate predictions. However, few studies have revealed that SBrC formation is affected by multifunctional RNCs, which has a non-negligible atmospheric abundance. Hence, we performed theoretical and experimental approaches to investigate the reaction mechanisms and kinetics of the mixtures for ammonium sulfate (AS), multifunctional amine (monoethanolamine, MEA) and GL. Our experiments indicate that the light-absorption and the growth rate are enhanced in MEA-GL mixture relative to AS-GL and MEA-AS-GL mixtures, and MEA reactions of the chromophores by more efficiently than the analogous AS reactions. Quantum chemical calculations show that the formation and propagation of oligomers proceed via four-step nucleophilic addition reactions in three reaction systems. The presence of MEA provides the extra two branched chains to affect the natural charges and steric hindrance of intermediates, facilitated the formation of chromophores. Molecule dynamics simulations reveal that the interfacial and interior attraction on the aqueous aerosols with MEA is more pronounced for small α-dicarbonyls, to facilitate the further engagement in the aqueous-phase reactions. Our results show a possible missing source for SBrC formation on urban, regional and global scales. [ABSTRACT FROM AUTHOR]

The synthesis of substituted 2,4,6,8,10,12-hexaazaisowurtzitane via direct condensation is challenging. The selection of starting ammonia derivatives is very limited. The important step in developing alternative synthetic routes to these compounds is to investigate their formation process in detail. Here, we examined an acid-catalyzed condensation between benzyl carbamate and glyoxal in a ratio of 2:1 in a range of polar protic and aprotic solvents, and discovered a new process occurring during the cascade condensation of glyoxal with ammonia derivatives as well as discovered several processes hindering the formation of caged compounds. More specifically, a cyclic compound, N,N′-bis(carbobenzoxy)-3,6-diamino-1,4-dioxane-2,5-diol, was found to form at the early stage of condensation under low acidity conditions. The formation of this compound is governed by an easier condensation of alcohol groups compared to the amide ones. The condensation intermediates, N,N′-bis(carbobenzoxy)ethan-1,2-diol, N,N′,N″-tris(carbobenzoxy)ethanol, and N,N′,N″,N‴-tetrakis(carbobenzoxy)ethan, were obtained at a higher acidity. A range of solvents were identified: those that react with benzyl carbamate, those that promote the progress of side processes, and those that promote precipitation of condensation intermediates. A few byproducts were isolated and identified. It was found that DMSO exhibits a strong deactivating ability, while CH3CN exhibits a strong activating ability towards the acid-catalyzed condensation process of benzyl carbamate with glyoxal. [ABSTRACT FROM AUTHOR]

The work addresses the use of bio-based and –degradable materials for the production of a moist, adaptive and anti-microbial wound dressing. The dressing is targeted to exhibit a pH-dependent active agent release. Xanthan hydrogel structures are coated on cellulose fabrics via stencil printing and subsequently cross-linked using glyoxal. By alteration of the cross-linker content from 1 to 6% by mass, the hydrogel elasticity can be tuned within a range of 2–16 kPa storage modulus. Increasing initial glyoxal concentrations also result in higher amounts of glyoxal release. Glyoxal, an anti-microbial agent with approval in veterinary medicine, is mostly released upon wound application supporting infection management. As wound simulation, normal saline, as pH 5 and pH 8 buffer solutions, were used. The release profile and magnitude of approx. 65%–90% glyoxal is pH-dependent. Increased release rates of glyoxal are present in pH 8 fluids, which mostly base on faster hydrogel swelling. Higher total glyoxal release is present in pH 5 fluid and normal saline after 3 days. Accordingly, a pH-dependent release profile was encountered. As glyoxal attacks any cell unselectively, it is expected to be effective against antibiotic resistant bacteria. By stencil printing the dressing size can be adjusted to minimize healthy glyoxal tissue exposure. [ABSTRACT FROM AUTHOR]

In this research, synthesis of different imidazopyridine derivatives was performed using aryl glyoxals, thiobarbituric acid, and 2-aminopyridine in the presence of acetic acid in ethanol at 80 °C. Different aryl glyoxals can be used in this method. Finally, the desired products were separated by simple filtration in excellent yields. The salient features of this protocol are a simple operation, mild reaction conditions, simple work up, easy product isolation, and preparation of potentially bioactive compounds. [ABSTRACT FROM AUTHOR]

Glycation is a non-enzymatic reaction wherein sugars or dicarbonyls such as methylglyoxal (MGO) and glyoxal (GO) react with proteins, leading to protein inactivation. The hydrolysing enzyme human deglycase-1 (hDJ-1) is reported to decrease glycative stress by deglycating the modified proteins, specifically at cysteine, lysine, and arginine sites. This specificity of hDJ-1 is thought to be regulated by its active site cysteine residue (Cys106). Structural analysis of hDJ-1 by molecular docking and simulation studies, however, indicates a possible role of glutamate (Glu18) in determining its substrate specificity. To elucidate this, Glu18 present at the catalytic site of hDJ-1 was modified to aspartate (Asp18) by SDM, and the resultant mutant was termed mutant DJ-1 (mDJ-1). Both hDJ-1 and mDJ-1 were heterologously expressed in Escherichia coli BL21 (DE3) strain and purified to homogeneity. The hDJ-1 showed k cat values of 1.45 × 103 s−1, 3.6 × 102 s−1, and 3.1 × 102 s−1, and K m values 0.181 mM, 18.18 mM, and 12.5 mM for N- acetylcysteine (NacCys), N- acetyllysine (NacLys), and N- acetylarginine (NacArg), respectively. The mDJ-1 showed altered k cat values (8 × 102 s−1, 3.8 × 102 s−1, 4.9 × 102 s−1) and K m values of 0.14 mM, 6.25 mM, 5.88 mM for NacCys, NacLys and NacArg, respectively. A single amino acid change (Glu18 to Asp18) improved the substrate specificity of mDJ-1 toward NacLys and NacArg. Understanding hDJ-1's structure and enhanced functionality will facilitate further exploration of its therapeutic potential for the treatment of glycation-induced diabetic complications. [Display omitted] • Protein human deglycase-1 (hDJ-1) acts on amino acids with different specificities. • The structural analysis of hDJ-1 was performed to understand its substrate specificity. • Docking and MD simulation suggested the role of glutamate-18 in substrate specificity. • Glutamate was replaced with aspartate (E18D) to produce mutant protein mDJ-1. • mDJ-1 showed altered substrate specificity towards N -acetyllysine and N -acetylarginine. [ABSTRACT FROM AUTHOR]

Glyoxal oxidase (GLOX, EC 1.2.3.15) is a class of hydrogen peroxide synthases involved in lignin degradation. Several GLOX genes of biotrophic and necrotrophic phytopathogenic fungi have been confirmed to contribute to fungal growth, development, and pathogenicity. However, the composition, sequence characteristics and functions of genes in the GLOX family of hemi-biotrophic phytopathogenic fungi remain poorly understood. This study identified a GLOX- -encoding gene CsGLOX in the hemi-biotrophic phytopathogenic fungus Colletotrichum siamense by bioinformatics analysis and PCR cloning. The encoded protein contains a signal peptide and five cell wall stress-responsive component (WSC) domains at the N terminus, followed by a catalytic structural domain (AA5_1). CsGLOX-deficient mutants were constructed by homologous replacement, which significantly increased the formation of conidia and reduced the pathogenicity and the high-osmotic stress tolerance of the fungus. However, the deletions did not influence fungal filamentous growth. This study proposes that the CsGLOX gene is involved in pathogen conidial formation, pathogenicity, and osmotic stress response, which deepens our understanding of the pathogenic mechanism of hemi-biotrophic phytopathogenic fungus C. siamense. [ABSTRACT FROM AUTHOR]

Air quality is a prevalent concern due to its imposing health risks. The state of Utah, USA, at times over the last 20 years has suffered from some of the worst air quality in the nation. The propensity for the state of Utah to experience elevated concentrations of particulate matter and ozone can in part be attributed to its unique geography that features dry, mountainous topography. Valleys in Utah create ideal environments for extended cold-pool events. In this review, we summarize the research executed in Utah over the past 20 years (2002–2022) by dividing the state into six regions: Utah Valley, Summit County, Southern Utah (regions south of Utah Valley), Cache Valley, Uinta Basin, and Salt Lake Valley. We review the published literature chronologically and provide a summary of each region identifying areas where additional research is warranted. We found that the research effort is weighted towards Uinta Basin and Salt Lake Valley, with the other regions in Utah only adding up to 20% of the research effort. We identified a need for more source apportionment studies, speciated volatile organic compound (VOC) studies, and ozone isopleths. Where ozone isopleths are not able to be created, measurement of glyoxal and formaldehyde concentrations could serve as surrogates for more expensive studies to inform ozone mitigation policies. [ABSTRACT FROM AUTHOR]

Single-cell RNA sequencing has become an important method to identify cell types, delineate the trajectories of cell differentiation in whole organisms, and understand the heterogeneity in cellular responses. Nevertheless, sample collection and processing remain a severe bottleneck for single-cell RNA sequencing experiments. Cell isolation protocols often lead to significant changes in the transcriptomes of cells, requiring novel methods to preserve cell states. Here, we developed and benchmarked protocols using glyoxal as a fixative for single-cell RNA sequencing applications. Using Drop-seq methodology, we detected a large number of transcripts and genes from glyoxal-fixed Drosophila cells after single-cell RNA sequencing. The effective glyoxal fixation of transcriptomes in Drosophila and human cells was further supported by a high correlation of gene expression data between glyoxal-fixed and unfixed samples. Accordingly, we also found highly expressed genes overlapping to a large extent between experimental conditions. These results indicated that our fixation protocol did not induce considerable changes in gene expression and conserved the transcriptome for subsequent single-cell isolation procedures. In conclusion, we present glyoxal as a suitable fixative for Drosophila cells and potentially cells of other species that allow high-quality single-cell RNA sequencing applications. [ABSTRACT FROM AUTHOR]

Background: Histamine H2 receptor antagonists are a group of drugs that inhibit gastric juice secretion in gastrointestinal diseases. However, there is evidence to suggest that H2 blockers have a broader spectrum of activity. The antioxidant properties of H2 blockers have not been fully elucidated, and their anti-glycation potential has not been studied to date. Therefore, this is the first study to compare the antioxidant and antiglycation potentials of the most popular H2 antagonists (ranitidine, cimetidine, and famotidine) on protein glycoxidation in vitro. Methods: Bovine serum albumin (BSA) was glycated using sugars (glucose, fructose, galactose, and ribose) as well as aldehydes (glyoxal and methylglyoxal). Results: In the analyzed group of drugs, ranitidine was the only H2 blocker that significantly inhibited BSA glycation in all tested models. The contents of protein carbonyls, protein glycoxidation products (↓dityrosine, ↓N-formylkynurenine), and early (↓Amadori products) and late-stage (↓AGEs) protein glycation products decreased in samples of glycated BSA with the addition of ranitidine relative to BSA with the addition of the glycating agents. The anti-glycation potential of ranitidine was comparable to those of aminoguanidine and Trolox. In the molecular docking analysis, ranitidine was characterized by the lowest binding energy for BSA sites and could compete with protein amino groups for the addition of carbonyl groups. H2 blockers also scavenge free radicals. The strongest antioxidant properties are found in ranitidine, which additionally has the ability to bind transition metal ions. The systematic literature review also revealed that the anti-glycation effects of ranitidine could be attributed to its antioxidant properties. Conclusions: Ranitidine showed anti-glycation and antioxidant properties. Further research is needed, particularly in patients with diseases that promote protein glycation. [ABSTRACT FROM AUTHOR]

Reactive α-dicarbonyls (α-DCs), such as methylglyoxal (MGO), glyoxal (GO), and 3-deoxyglucosone (3-DG), are potent precursors in the formation of advanced glycation end products (AGEs). In particular, MGO and MGO-derived AGEs are thought to be involved in the development of vascular complications in diabetes. Experimental studies showed that citrus and pomegranate polyphenols can scavenge α-DCs. Therefore, the aim of this study was to evaluate the effect of a citrus and pomegranate complex (CPC) on the α-DCs plasma levels in a double-blind, placebo-controlled cross-over trial, where thirty-six elderly subjects were enrolled. They received either 500 mg of Citrus sinensis peel extract and 200 mg of Punica granatum concentrate in CPC capsules or placebo capsules for 4 weeks, with a 4-week washout period in between. For the determination of α-DCs concentrations, liquid chromatography tandem mass spectrometry was used. Following four weeks of CPC supplementation, plasma levels of MGO decreased by 9.8% (−18.7 nmol/L; 95% CI: −36.7, −0.7 nmol/L; p = 0.042). Our findings suggest that CPC supplementation may represent a promising strategy for mitigating the conditions associated with MGO involvement. This study was registered on clinicaltrials.gov as NCT03781999. [ABSTRACT FROM AUTHOR]

Background and Objectives: Gluten-free products have been produced as part of medical therapy and have gained popularity among individuals seeking weight loss or healthier dietary options. Assessing the potential risks associated with these products is essential in optimizing their compositions and developing new dietetic approaches. This study aimed to determine the glyoxal (GO) and methylglyoxal (MGO) contents in gluten-free bread, biscuits, and cookies and to examine their bioaccessibility using an in vitro gastrointestinal model. Materials and Methods: A total of 26 gluten-free and 19 gluten-containing (control) products were analyzed for their GO and MGO levels utilizing a high-performance liquid chromatography (HPLC) device. Results: Post-digestion, the GO and MGO values increased significantly across all food groups compared with pre-digestion values (p < 0.05), and the bioaccessibility exceeded 100%. Specifically, gluten-free bread exhibited higher post-digestion GO and MGO values than the control group (p < 0.05). Conversely, gluten-containing biscuits and cookies had higher post-digestion GO and MGO values compared to gluten-free products (p < 0.05). Conclusions: The detection of precursors to advanced glycation end products (AGEs) in gluten-free products has drawn attention to the potential health risks associated with their consumption. Therefore, reevaluation of the formulations and technologies used in these products and the introduction of new strategies are crucial in mitigating AGE content. [ABSTRACT FROM AUTHOR]

Aqueous secondary organic aerosol (aqSOA) formation from volatile and semivolatile organic compounds at the air-liquid interface is considered as an important source of fine particles in the atmosphere. However, due to the lack of in situ detecting techniques, the detailed interfacial reaction mechanism and dynamics still remain uncertain. In this study, synchrotron-based vacuum ultraviolet single-photon ionization mass spectrometry (VUV SPI-MS) was coupled with the System for Analysis at the Liquid Vacuum Interface (SALVI) to investigate glyoxal dark oxidation products at the aqueous surface. Mass spectral analysis and determination of appearance energies (AEs) suggest that the main products of glyoxal dark interfacial aging are carboxylic acid related oligomers. Furthermore, the VUV SPI-MS results were compared and validated against those of in situ liquid time-of-flight secondary ion mass spectrometry (ToF-SIMS). The reaction mechanisms of the dark glyoxal interfacial oxidation, obtained using two different approaches, indicate that differences in ionization and instrument operation principles could contribute to their abilities to detect different oligomers. Therefore, the mechanistic differences revealed between the VUV SPI-MS and ToF-SIMS indicate that more in situ and real-time techniques are needed to investigate the contribution of the air-liquid interfacial reactions leading to aqSOA formation.

α-Dicarbonyls are significant degradation products resulting from the Maillard reaction during food processing. Their presence in foods can indicate the extent of heat exposure, processing treatments, and storage conditions. Moreover, they may be useful in providing insights into the potential antibacterial and antioxidant activity of U.S. honey. Despite their importance, the occurrence of α-dicarbonyls in honey produced in the United States has not been extensively studied. This study aims to assess the concentrations of α-dicarbonyls in honey samples from different regions across the United States. The identification and quantification of α-dicarbonyls were conducted using reverse-phase liquid chromatography after derivatization with o-phenylenediamine (OPD) and detected using ultraviolet (UV) and mass spectrometry methods. This study investigated the effects of pH, color, and derivatization reagent on the presence of α-dicarbonyls in honey. The quantification method was validated by estimating the linearity, precision, recovery, method limit of detection, and quantification using known standards for GO, MGO, and 3-DG, respectively. Three major OPD-derivatized α-dicarbonyls including methylglyoxal (MGO), glyoxal (GO), and 3-deoxyglucosone (3-DG), were quantified in all the honey samples. 3-Deoxyglucosone (3-DG) was identified as the predominant α-dicarbonyl in all the U.S. honey samples, with concentrations ranging from 10.80 to 50.24 mg/kg. The total α-dicarbonyl content ranged from 16.81 to 55.74 mg/kg, with the highest concentration measured for Southern California honey. Our results showed no significant correlation between the total α-dicarbonyl content and the measured pH solutions. Similarly, we found that lower amounts of the OPD reagent are optimal for efficient derivatization of MGO, GO, and 3-DG in honey. Our results also indicated that darker types of honey may contain higher α-dicarbonyl content compared with lighter ones. The method validation results yielded excellent recovery rates for 3-DG (82.5%), MGO (75.8%), and GO (67.0%). The method demonstrated high linearity with a limit of detection (LOD) and limit of quantitation (LOQ) ranging from 0.0015 to 0.002 mg/kg and 0.005 to 0.008 mg/kg, respectively. Our results provide insights into the occurrence and concentrations of α-dicarbonyl compounds in U.S. honey varieties, offering valuable information on their quality and susceptibility to thermal processing effects.

The detection and analysis of α-dicarbonyl compounds (α-DCs) in food can guide the daily diet of patients with various chronic diseases. However, these compounds have poor stability, lack color-generating groups, and have low ionization efficiency. Therefore, it is difficult to monitor them. We established a new simple and sensitive method for the simultaneous determination of four α-DCs, including glyoxal (GO), methylglyoxal (MG), 2,3-butanedione (DMGO), and 3-deoxyglucosone (3-DG) in beer by ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS) with pre-column derivatization using 3-benzyl-2-oxo-4λ3-thiazolidine-4-carbohydrazide (BOTC), a novel MS probe for targeted identification of carbonyl compounds. α-DCs were derivatized with BOTC at 60 °C for 60 min, and the gradient analysis was carried out on a CSH C18 (2.1 mm × 50 mm; 1.7 μm) column for 5 min with a mobile phase A of 0.1% formic acid (FA) in water and mobile phase B of 0.1% FA in acetonitrile. The linearity range of this method was 0.39–500 μM (R2 ≥ 0.9995). The limits of detection (LOD) were in the range of 13–50 fmol. The average recoveries of α-DCs were 95.15–101.67%. This method was successfully applied to the detection of α-DCs in beer; the content of 3-DG was the highest, several hundred times higher than that of GO, MG, and DMGO, and the difference was significant. This new BOTC derivatization-based UHPLC-MS/MS method for the simultaneous detection of four α-DCs in beer is highly sensitive and can be used for the detection of α-DCs in alcoholic beverages. [ABSTRACT FROM AUTHOR]

The formation of the most widely used antithyroid drug in the world, 1-methyl-1H-imidazole-2(3H)-thione (methimazole or thiamazole), by the reduction of 4,5-dihydroxy-1-methylimidazolidine-2-thione (1-Me-DHIT) with 1-methylthiourea or by the reaction of 1-methylthiourea excess and glyoxal were studied. A new method for the synthesis of methimazole from available reagents, 1-Me-DHIT and 1-methylthiourea, was proposed. [ABSTRACT FROM AUTHOR]

Human exposure to dicarbonyls occurs via ingestion (e.g., food), inhalation (e.g., electronic cigarettes) and dysregulation of endogenous metabolic pathways (e.g., glycolysis). Dicarbonyls are electrophiles able to induce carbonylation of endogenous substrate. They have been associated with the onset and progression of several human diseases. Several studies have advocated the use of dicarbonyl binders as food preservatives or as drugs aimed at mitigating carbonylation. This study presents the setup of an easy and cheap assay for the screening of selective and potent dicarbonyl binders. The method is based on the incubation of the candidate molecules with a molecular probe. The activity is then determined by measuring the residual concentration of the molecular probe over time by liquid chromatography (LC). However, the naturally occurring dicarbonyls (e.g., glyoxal, methylglyoxal) are not appealing as probes since they are hard to separate and detect using the most popular LC variants. Benzylglyoxal (BGO) was therefore synthesized and tested, proving to be a convenient probe that allows a direct quantification of residual dicarbonyls by reversed phase LC without derivatization. The method was qualified by assessing the binding ability of some molecules known as binders of natural occurring dicarbonyls, obtaining results consistent with literature. [ABSTRACT FROM AUTHOR]

Background: Hyperglycaemia is frequent in acute ischemic stroke and denotes a bad prognosis, even in the absence of pre-existing diabetes. However, in clinical trials treatment of elevated glucose levels with insulin did not improve stroke outcome, suggesting that collateral effects rather than hyperglycaemia itself aggravate ischemic brain damage. As reactive glucose metabolites, glyoxal and methylglyoxal are candidates for mediating the deleterious effects of hyperglycaemia in acute stroke. Methods: In 135 patients with acute stroke, we used liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) to measure glyoxal, methylglyoxal and several of their glycated amino acid derivatives in serum. Results were verified in a second cohort of 61 stroke patients. The association of serum concentrations with standard stroke outcome scales (NIHSS, mRS) was tested. Results: Glucose, glyoxal, methylglyoxal, and the glyoxal-derived glycated amino acid Nδ-(5-hydro-4-imidazolon-2-yl)ornithine (G-H1) were positively correlated with a bad stroke outcome at 3 months as measured by mRS90, at least in one of the two cohorts. However, the glycated amino acids Nε-carboxyethyllysine (CEL) and in one cohort pyrraline showed an inverse correlation with stroke outcome probably reflecting lower food intake in severe stroke. Patients with a poor outcome had higher serum concentrations of glyoxal and methylglyoxal. Conclusions: The glucose-derived α-dicarbonyl glyoxal and glycated amino acids arising from a reaction with glyoxal are associated with a poor outcome in ischemic stroke. Thus, lowering α-dicarbonyls or counteracting their action could be a therapeutic strategy for hyperglycaemic stroke. [ABSTRACT FROM AUTHOR]

A comprehensive study on the properties and implementation of glyoxylic‐acetals in sodium‐ion energy storage systems is presented. Electrolytes containing 1,1,2,2‐tetramethoxyethane (tetramethoxyglyoxal, TMG), 1,1,2,2‐tetraethoxyethane (tetraethoxyglyoxal, TEG) and a mixture of the latter with propylene carbonate (PC) exhibit increased thermal stabilities and higher flash points compared to classical electrolytes based on carbonates as solvents. Due to its favorable properties, 1 m NaTFSI in TEG/PC (3 : 7), has been selected and used for sodium‐ion energy storage systems based on a Prussian Blue (PB) positive electrode and a hard carbon (HC) negative electrode. Compared to conventional electrolyte (based on a 1 : 1 mixture of ethylene carbonate, EC, and dimethyl carbonate, DMC), this glyoxylic‐acetal electrolyte provides competitive capacity and prolonged cycle life. Postmortem XPS analysis indicates that the electrode‐electrolyte interphases formed in presence of TEG are thicker and presumably more protective, inhibiting typical degradation processes of the electrodes. Furthermore, it is demonstrated that the suitable properties of TEG on the cycling stability can also be exploited for the construction of highly stable sodium‐ion capacitors. [ABSTRACT FROM AUTHOR]

Glyoxal and methylglyoxal are important volatile organic compounds in the atmosphere. The gas–particle partitioning of these carbonyl compounds makes significant contributions to O3 formation. In this study, both the gas- and particle-phase glyoxal and methylglyoxal concentrations at the foot and top of Mount Hua were determined simultaneously. The results showed that the gaseous-phase glyoxal and methylglyoxal concentrations at the top were higher than those at the foot of the mountain. However, the concentrations for the particle phase showed the opposite trend. The average theoretical values of the gas–particle partitioning coefficients of the glyoxal and methylglyoxal concentrations (4.57 × 10−10 and 9.63 × 10−10 m3 μg−1, respectively) were lower than the observed values (3.79 × 10−3 and 6.79 × 10−3 m3 μg−1, respectively). The effective Henry's law constants (eff.KH) of the glyoxal and methylglyoxal were in the order of 108 to 109 mol/kgH2O/atm, and they were lower at the foot than they were at the top. The particle/gas ratios (P/G ratios) of the glyoxal and methylglyoxal were 0.039 and 0.055, respectively, indicating more glyoxal and methylglyoxal existed in the gas phase. The factors influencing the partitioning coefficients of the glyoxal and methylglyoxal were positively correlated with the relative humidity (RH) and negatively correlated with the PM2.5 value. Moreover, the partitioning coefficient of the glyoxal and methylglyoxal was more significant at the top than at the foot of Mount Hua. [ABSTRACT FROM AUTHOR]

The kinetics of elimination of various dicarbonyl-modified low-density lipoproteins from the bloodstream of Macaca mulatta monkeys were investigated. The low-density lipoproteins (LDL) in the monkey blood plasma were isolated by density gradient ultracentrifugation and labeled in vitro with the fluorescent dye FITC; thereupon, they were modified with different natural low molecular-weight dicarbonyls: malondialdehyde (MDA), glyoxal, or methylglyoxal. The control native FITC-labeled LDL and dicarbonyl-modified FITC-labeled LDL were injected into the monkey's ulnar vein; thereafter, blood samples were taken at fixed time intervals during 24 h. The plasma level of FITC-labeled LDL was determined with spectrofluorimetry. The study established that glyoxal- and monkeysglyoxal-labeled LDL circulated in monkey virtually at the same time as native (non-modified) LDL. In contrast, MDA-modified LDL disappeared from the blood extremely rapidly. Administration of the PCSK9 inhibitor involocumab (which increases LDL utilization) to patients with coronary heart disease (CHD) was found to significantly reduce levels of MDA-modified LDL. [ABSTRACT FROM AUTHOR]

Density functional theory (DFT) and the Møller–Plesset expansion (MP2) calculations were benchmarked to characterize the structure of novel derivatives of carbene hydroxymethylene. In this regard, eleven numbers of primary aldehydes including formaldehyde, acetaldehyde, formyl chloride, 2-chloroacetaldehyde, formyl fluoride, 2-fluoroacetaldehyde, formic acid, propionaldehyde, glyoxal, methyl formate, and formyl bromide (1H–11Br) were scrutinized, at the B3LYP/6-311++G(3d,3p) level of theory. Thereafter, the process of keto-enol tautomerism via a [1,2]-H-shift of 1H–11Br was monitored to reach their corresponding enol forms (1P–11P). For all species (except for one structure), the TS involves a triangle structure of C–O–H and yields cis or trans isomers of a singlet ground-state (S) carbene that contrasts the multiplicity of ordinary carbenes. The bond dissociation energy (BDE) calculations were carried out for the homolytic cleavage of C–H bonds of 1H–11Br. The AIM, as a promising analysis that definitely reveals the nature of the bond, was conducted to characterize the eigenvalues at the bond critical points (BCPs). In addition, the relation between the Hammett equation and thermodynamic parameters was obtained. Our investigation suggests new stable S derivatives of carbene hydroxymethylene that can be isolated. [ABSTRACT FROM AUTHOR]

The aldol reaction is one of the most important carbon‐carbon bond‐forming reactions in organic chemistry. Asymmetric direct cross‐aldol reaction of two different aldehydes has been regarded as a difficult reaction because of the side reactions such as self‐aldol reaction and over reaction. We found that trifluoromethyl‐substituted diarylprolinol, α,α‐bis[3,5‐bis(trifluoromethyl)phenyl]‐2‐pyrrolidinemethanol (1), is an effective organocatalyst that promotes several cross‐aldol reactions of aldehydes with excellent diastereo‐ and enantioselectivities. Acetaldehyde can be employed as a suitable nucleophilic aldehyde. Successful electrophilic aldehydes are ethyl glyoxylate, chloroacetaldehyde, dichloroacetaldehyde, chloral, α‐alkyl‐α‐oxo aldehyde, trifluoroacetaldehyde, glyoxal, alkenyl aldehyde, alkynyl aldehyde, and formaldehyde. Some of the aldehydes are commercially available as a polymer solution, an aqueous solution, or in the hydrated form. They can be used directly in the asymmetric aldol reaction as a commercially available form, which is a synthetic advantage. Given that the obtained aldol products possess several functional groups along with a formyl moiety, they are synthetically useful chiral building blocks. [ABSTRACT FROM AUTHOR]

In this study, airborne measurements of the sum of hydroperoxyl (HO2) and organic peroxy (RO2) radicals that react with nitrogen monoxide (NO) to produce nitrogen dioxide (NO2), coupled with actinometry and other key trace gases measurements, have been used to test the current understanding of the fast photochemistry in the outflow of major population centres. The measurements were made during the airborne campaign of the EMeRGe (Effect of Megacities on the transport and transformation of pollutants on the Regional to Global scales) project in Europe on board the High Altitude and Long Range Research Aircraft (HALO). The measurements of RO 2∗ on HALO were made using the in situ instrument Peroxy Radical Chemical Enhancement and Absorption Spectrometer (PeRCEAS). RO 2∗ is to a good approximation the sum of peroxy radicals reacting with NO to produce NO2. RO 2∗ mixing ratios up to 120 pptv were observed in air masses of different origins and composition under different local actinometric conditions during seven HALO research flights in July 2017 over Europe. Radical production rates were estimated using knowledge of the photolysis frequencies and the RO2∗ precursor concentrations measured on board, as well as the relevant rate coefficients. Generally, high RO2∗ concentrations were measured in air masses with high production rates. In the air masses investigated, RO2∗ is primarily produced by the reaction of O 1 D with water vapour and the photolysis of nitrous acid (HONO) and of the oxygenated volatile organic compounds (OVOCs, e.g. formaldehyde (HCHO) and glyoxal (CHOCHO)). Due to their short lifetime in most environments, the RO 2∗ concentrations are expected to be in a photostationary steady state (PSS), i.e. a balance between production and loss rates is assumed. The RO2∗ production and loss rates and the suitability of PSS assumptions to estimate the RO2∗ mixing ratios and variability during the airborne observations are discussed. The PSS assumption for RO2∗ is considered robust enough to calculate RO2∗ mixing ratios for most conditions encountered in the air masses measured. The similarities and discrepancies between measured and PSS calculated RO2∗ mixing ratios are discussed. The dominant terminating processes for RO2∗ in the pollution plumes measured up to 2000 m are the formation of nitrous acid, nitric acid, and organic nitrates. Above 2000 m, HO2 – HO2 and HO2 – RO2 reactions dominate the RO2∗ removal. RO2∗ calculations by the PSS analytical expression inside the pollution plumes probed often underestimated the measurements. The underestimation is attributed to the limitations of the PSS equation used for the analysis. In particular, this expression does not account for the yields of RO2∗ from the oxidation and photolysis of volatile organic compounds, VOCs, and OVOCs other than those measured during the EMeRGe research flights in Europe. In air masses with NO mixing ratios ≤50 pptv and low VOC/NO ratios, the RO2∗ measured is overestimated by the analytical expression. This may be caused by the formation of H 2 O and O 2 from OH and HO2 , being about 4 times faster than the rate of the OH oxidation reaction of the dominant OVOCs considered. [ABSTRACT FROM AUTHOR]

The crosslinking mechanism of glyoxal and asparagine was analyzed, and the relationship between the mechanism and practical performances of soy protein-based adhesives was also discussed. It is shown that when pH=1 and 3, glyoxal reacted with asparagine in the form of major cyclic ether compounds. When pH =5, glyoxal reacted with asparagine in two structural forms of sodium glycollate and cyclic ether compounds. However, amidogens of asparagine were easy to develop protonation under acid conditions. Supplemented by the instability of cyclic ether compounds, the reaction activity and reaction degree between glyoxal and asparagine were relatively small. Under alkaline conditions, glyoxal mainly reacted with asparagine in the form of sodium glycollate. With the increase of pH, the polycondensation was more sufficient and the produced polycondensation products were more stable. The reaction mechanism between glyoxal and asparagine had strong correspondence to the practical performances of the adhesives. Glyoxal solution could develop crosslinking reactions with soy protein under both acid and alkaline conditions. Bonding strength and water resistance of the prepared soy protein-based adhesives were increased significantly. When pH>7, glyoxal had relatively high reaction activity and reaction intensity with soy protein, and the prepared adhesives had high crosslinking density and cohesion strength, showing relatively high bonding strength, water resistance and thermal stability. [ABSTRACT FROM AUTHOR]

Three α-dicarbonyl compounds, methylglyoxal (MGO), diacetyl (DA) and glyoxal (GO) were common highly reactive glycosylation intermediates that can cause damage to biological macromolecules (e. g. DNA) in the body. The interaction properties of MGO, DA and GO with calf thymus DNA (ctDNA) were determined by multispectral methods combined with computer simulation techniques. Analysis of UV spectra indicated that MGO, DA and GO binding to ctDNA spontaneously were mainly driven by van der Waals forces and hydrogen bonding, and the energy distribution in molecular dynamics simulations supported this conclusion. The binding constants of MGO, DA and GO with ctDNA at 25 ℃ were close to those of classical groove-binders, with corresponding values of 2.99×10³, 1.96×10³ and 1. 05×10³ L·mol-1, respectively. NaCl, single and double-stranded DNA, thermal denaturation, viscosity and CD spectroscopy experiments demonstrated that MGO, DA and GO were all bound to ctDNA via groove binding. Molecular docking visualization showed that MGO, DA and GO were bound in the AT-rich minor groove region of DNA, with DT7 and DA18 being the active sites of binding. Molecular dynamics simulations of the MGO-ctDNA complex had higher root mean square deviation, radius of gyration, and root mean square fluctuation values than free DNA, indicating that the binding of MGO loosened and tended to destabilise parts of the DNA structure. Gel electrophoresis experiments showed that MGO, DA and GO could damage plasmid DNA in the presence of lysine and Cu2+, and MGO and GO even completely disrupted the superhelical morphology of DNA. [ABSTRACT FROM AUTHOR]

Pinus elliottii Engelm bark is a byproduct of Uruguay's milling industry. As a circular economy strategy, it is burned in broilers for energy production. Aiming to increase the added value of the bark, this work analyzes the extraction of its tannins to use them in the development of formaldehyde-free adhesives, while evaluating whether it retains its calorific power for further energy production. The best extraction conditions (methanol at 65 °C for 2 h) were identified at a laboratory level after which they were scaled up to 50 L, which did not affect extraction yield. The Stiasny number remained above 65%, meaning the extractive was suitable for its use in adhesive formulations. The characterization of the extractives was completed with molecular weight distribution, FTIR-ATR, ABES and DSC. Finally, two formaldehyde-free adhesive formulations were developed using hexamine and glyoxal as hardeners. Their behaviors were compared through rheological analysis, DSC and ABES. It was determined that the adhesive formulations with hexamine at pHs of 8 and 10 are suitable for their use in the timber industry. It was noted that they react the best at a pressing temperature of 160 °C. After the extraction, the calorific power of the P. elliottii Engelm bark decreased by only 13%, thus remaining useful for energy production. [ABSTRACT FROM AUTHOR]

A simple, facile, and highly efficient approach has been unfolded for the syntheses of β‐carboline tethered imidazole derivatives. This expeditious catalyst‐free strategy proceeds through the assembly of 1‐formyl‐9H‐β‐carbolines, glyoxal derivatives and ammonium acetate via the formation of concomitant four C−N bonds in a one‐pot operation. The current approach has various advantages, including multicomponent nature, simple reaction conditions, short reaction time, broad substrate scope, and high product yield. Importantly, the β‐carboline tethered imidazole derivatives displayed excellent photophysical properties with quantum yield up to 90%. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the mechanisms by which amino acids simultaneously remove formaldehyde and glyoxal and to evaluate the cytotoxicity of their products. γ-Aminobutyric acid or L-alanine was reacted with formaldehyde and glyoxal at a molar ratio of 5:1:1 for 95 ℃, 4 h. The amounts of residual formaldehyde and glyoxal were tested by the 2,4-dinitrophenyl hydrazine (2,4-DNPH) derivatization method. Formaldehyde was found to promote the removal of glyoxal by γ-aminobutyric acid, increasing the removal rate from 55.8% to 70.6%. Similarly, glyoxal could promote the removal of formaldehyde by L-alanine, increasing the removal rate from 2% to 41.3%. The major products were identified as imidazole salts using high-resolution mass spectrometry (HR-MS) and nuclear magnetic resonance spectroscopy (NMR). The reaction mechanism was that the dehydration reaction between one molecule of amino acid and one molecule of formaldehyde took place to form Mannich base, which reacted with one molecule of amino acid to produce an immediate product with two imine groups, attacking glyoxal via nucleophilic addition and finally resulting in the formation of imidazole salts by dehydration reaction. The imidazole salts formed with γ-aminobutyric acid or L-alanine significantly attenuated the cytotoxicity of formaldehyde and glyoxal. Both imidazole salts were detected in commercial and home-made potato chips and biscuits, and their contents could be greatly increased by addition of L-alanine and γ-aminobutyric acid to the raw materials. The results of this study indicated that γ-aminobutyric acid and L-alanine have potential application in the reduction and control of formaldehyde and glyoxal in thermally processed foods.

This study aimed to improve some surface properties such as color, gloss, and surface roughness changes of Oriental beech (Fagus orientalis L.) wood impregnated with some water repellent chemicals such as glycerol (GR) and glyoxal (GX) after weathering. Oriental beech wood specimens were impregnated with a 4 % aqueous solution of GR, GX, and a mixture of GR and GX (1:1; weight : weight) (GR+GX) and then exposed to weathering in Muğla Province in Turkey. Results showed that [delta]L* values of all wood specimens were decreased after weathering. Moreover, the decreases in the control specimen were higher than in the impregnated wood specimens. Oriental beech wood specimens showed a greenish and yellowish tendency, giving -[delta]a* and +[delta]b* values, respectively. Total color changes of GR impregnated Oriental beech was the lowest after weathering. The gloss of all Oriental beech test specimens decreased after weathering. The control specimen gave the lowest value in all three surface roughness parameters (Ra, Rz, and Rq) after weathering. Among the impregnated specimens, the groups impregnated with GR had, in general, the highest value in all three roughness degrees and showed the most negative results in surface roughness.

Chemical crosslinking is an established method for improving the wet performance of paper. In the chemical crosslinking process, covalent bonds are formed between cellulosic surfaces. The formed intra- and inter-fiber bonds increase the paper’s wet strength and reduce its water absorptivity. The majority of published studies concern crosslinking treatments with glyoxal, citric acid (CA), or with 1,2,3,4-butanetetra-carboxylic acid (BTCA). The most severe disadvantage of the crosslinking treatments with glyoxal, CA, and BTCA is that the formed crosslinks make the fibers and the paper more brittle. This downside effect has largely impeded the utilization of crosslinking in paper and paperboard making. In the present study, handsheets made from Nordic bleached softwood kraft pulp (NBSK) were crosslinked with methylated 1,3-dimethylol-4,5-dihydroxyethylene urea (mDMDHEU), which is commonly used in cotton fabric finishing. Similar to using glyoxal and citric acid, crosslinking with mDMDHEU notably increased the handsheet wet strength and decreased the water absorption. Compared to the use of glyoxal or CA, the crosslinking with mDMDHEU did not make the handsheets that brittle. These results suggest that mDMDHEU could be a more viable crosslinking agent for improving the wet performance of paper products.

ABSTRACT: Introduction. The article presents the results of studies of the effect of complex additive based on glyoxal on the properties of cement-based foam concrete mix and foam concrete of natural hardening. The relevance of the study is determined by the necessity to provide the required process parameters of mixture for transportation and laying the formwork, as well as providing strength and thermal and physical characteristics of wall structures for the development of the northern regions of Russia, including the Arctic zone. It has been proposed to decrease the shrinkage deformations of the concrete mix and increase compressive strength of hardened foam concrete by affecting the cement matrix with complex modifier based on glyoxal. Materials and methods. The effect of modifying additives on the properties of the foam concrete mixture and foam concrete was studied at a W/S mixture ratio of 0.45. Research has been carried out using test methods set out in national standards. The results of the study of the effect of complex modifying additives (CMA) based on an aqueous solution of glyoxal and organic acids on the rheological and strength properties of foam concrete are presented, the regularities of the processes and the mechanism of structure formation of the modified foam concrete are determined. Results. The use of modifying additives leads to increase result in increasing the aggregative stability and reducing the plastic shrinkage of the foam concrete mix by 22–70%. In foam concrete with the complex additive LA 0.5% + Gl 0.55% the compressive strength rises from 1.96 to 2.43 MPa at the age of 28 days while maintaining the average density of D600. The thermal conductivity coefficient of foam concrete modified with various additives decreased by 5–30% compared to references. Conclusions. The obtained results of the study create in the construction industry the basis for the import substitution of modifying additives on the domestic mineral resource base and the production of effective structural and heatinsulating concretes for the development of the northern regions of Russia.

Examples of air- and water-stable main-group radicals are scarce in the literature due to the higher reactivity of radical compounds as well as several synthetic challenges. Herein, we report two stable structurally characterized glyoxal radical cations (1˙+ and 2˙+) stabilized by cyclic(alkyl)(amino)carbene (CAAC) and bicyclic (alkyl)(amino)carbene (BICAAC), respectively. Both 1˙+ and 2˙+ are stable under harsh conditions such as strong acids, bases, mild oxidizing agents, and reducing agents, as well as towards bovine serum. Radical (2˙+) represents the first isolated radical stabilized by a BICAAC ligand. [ABSTRACT FROM AUTHOR]

Constructed on the benzothiazole-oxanthracene structure, a fluorescent probe RBg for Cu+ was designed under the ESIPT mechanism and synthesized by incorporating amide bonds as the connecting group and glyoxal as the identifying group. Optical properties revealed a good sensitivity and a good linear relationship of the probe RBg with Cu+ in the concentration range of [Cu+] = 0–5.0 μmol L−1. Ion competition and fluorescence-pH/time stability experiments offered further possibilities for dynamic Cu+ detection in an aqueous environment. HRMS analysis revealed a possible 1:1 combination of RBg and Cu+. In addition, colorimetric Cu+ detection and lysosome-targeted properties of the probe RBg were analyzed through RBg-doped PVDF nanofiber/test strips and RBg-Mito/Lyso trackers that were co-stained in living HeLa cells, enabling the probe's future applications as real-time detection methods for dynamic Cu+ tracking in the lysosomes and Cu+ detection under diversified conditions. [ABSTRACT FROM AUTHOR]

The present work, highlights a highly effective unique procedure for the synthesis of N,3‐diphenybenzo[d]imidazo[2,1‐b]thiazoles and oxybis(1‐phenyl‐2‐(phenylamino)ethanones) via the one‐pot three‐component reaction between aryl glyoxal, aryl amine, and 2‐aminobenzothiazole under catalyst‐free conditions. The present mild and green method uses EtOH without catalyst at reflux conditions. No catalyst with high yields, availability of the starting materials, operational simplicity, cleaner reaction profile, no harmful byproducts, and the isolated products in pure form are the advantages of this protocol. Structures of all the freshly synthesized products have been deduced by their FT‐IR, 1H‐NMR, 13C‐NMR, and elemental analysis. [ABSTRACT FROM AUTHOR]

One of the most important by-products generated in the forestry industry is the bark obtained during the debarking process. Pine (Pinus radiata D. Don) and eucalyptus (Eucalyptus globulus L.) are the main important tree species exploited in the Chilean forestry industry. The bark of P. radiata D. Don is an interesting source of extracts, rich in condensed tannins, with potential uses in biopolymer and bioadhesive preparation. Conversely, the E. globulus bark extracts are rich in hydrolyzable tannins with few applications. Nevertheless, the forest industry generates a high volume of these by-products, simultaneously. Then, it is interesting to determine a suitable process for the joint valorization of both forest by-products at a large scale. In this work, alkaline extraction (NaOH and Na2SO3) was performed at a pilot scale of a mixture of E. globulus and P. radiata barks prepared at different ratios (0%–100%). The effect of bark mixture composition on the resulting extract's properties was evaluated. All extracts were characterized according to their chemical composition by FTIR-ATR, MALDI-TOF, and molecular weight distribution (GPC). In addition, the Stiasny number was tested to determine the potential use of extracts in bioadhesive formulation. The self-condensation reaction of resulting extracts was studied using Dynamic Mechanical Analysis (DMA) and Automated Bond Evaluation System (ABES) techniques. Results show a good interaction between condensed and hydrolyzable tannins from both species' barks. It also demonstrated the potential application of the obtained extracts, for a bark ratio of 50:50, in the formulation of bioadhesives for particleboard manufacture. The obtained product showed a similar performance to that of the bioadhesive formulated with the extract obtained using only P. radiata bark. [ABSTRACT FROM AUTHOR]

Rfn (formaldehyde/nitrogen dioxide) is a common indicator based on satellite observations used to classify ozone formation sensitivity. However, it may underestimate anthropogenic volatile organic compounds (VOCs) in heavily polluted cities when only formaldehyde (HCHO) is used in Rfn to measure VOCs, since it is mainly derived from natural sources worldwide. In this study, we used multiaxis differential optical absorption spectroscopy to acquire tropospheric observations of nitrogen dioxide (NO2), HCHO and glyoxal (CHOCHO) in Beijing from 1 April 2019 to 31 March 2020. Combined with VOCs detected simultaneously by gas chromatography—mass spectrometry and proton transfer reaction–time-of-flight/mass spectrometry near the ground, we evaluated the representativeness of HCHO column densities on total VOCs (TVOC) in equivalent propylene concentrations, which is called reactivity. The results showed that there were significant seasonal differences in the response of HCHO to TVOC reactivity, with fitting slopes of 2.3 (spring), 2.6 (summer), 2.9 (autumn) and 1.0 (winter) in the four seasons, respectively. Since CHOCHO can be used to partly characterize the contribution of anthropogenic VOC emissions and demonstrated a better response to TVOC reactivity in winter, with fitting slopes of 0.2 (spring), 0.2 (summer), 0.2 (autumn) and 0.5 (winter) in the four seasons, respectively, we introduced CHOCHO to construct a new indicator (HCHO + 6 × CHOCHO). The fitting slopes of the four seasons were more similar, being 3.2 (spring), 3.6 (summer), 4.0 (autumn) and 4.0 (winter). The ratio of the new indicator to NO2, Rmn ((HCHO + 6 × CHOCHO)/NO2), was used to reclassify the ozone formation sensitivity of urban areas in North China, revealing that it is a transition regime before 1300 LST (LST = UST + 8) and an NOx-limited regime afterwards. Rmn improved the sensitivity from the VOC-limited regime to the NOx-limited regime, enhancing the sensitivity of NOx and providing new robust support for ozone pollution prevention and control. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Comprehensive Summary: 2,4,6,8‐Tetraazanoradamantane skeleton is a unique rigid cage‐like organic structure that has not been established. In this article, a facile protocol to build all‐bridge‐position‐functionalized 2,4,6,8‐tetraazanoradamantane skeleton by condensation of glyoxal, primary amines and disubstituted malondialdehydes, which were in situ generated from 2,2‐dipropenyl‐1,3‐dioxolane or 4,4‐dimethoxyhepta‐2,5‐diene via ozonation, is reported for the first time. A variety of primary amines are compatible with this process, and the corresponding 2,4,6,8‐tetraalkyl‐2,4,6,8‐tetraazanoradamantane‐9‐one ethylene or methyl ketals were achieved in 16%—58% yields. N‐Benzyl group could be converted to other functionalities such as acetyl and nitro, which indicates the structural diversity of this scaffold. [ABSTRACT FROM AUTHOR]

Copyright of Wood Industry / Drvna Industrija is the property of Drvna Industrija and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Lithium-sulfur batteries (LSBs) are among the most promising next generation battery technologies. First prototype cells show higher specific energies than conventional Li-ion batteries (LIBs) and the active material is cost-effective and ubiquitously abundant. However, Li-S batteries still suffer from several limitations, mainly the cycle life, inflation of cells, and also the lack of a component production value chain. As this battery system is based on a complex conversion mechanism, the electrolyte plays a key role, not only for specific energy, but also for rate capability, cycle stability and costs. Herein, we report on electrolytes based on glyoxylic-acetal based solvents, Tetraethoxyglyoxal (TEG) and Tetramethoxyglyoxal (TMG). These solvents have been examined before for supercapacitors and LIBs, but never for LSBs, although they exhibit some beneficial properties, and the production value chain has already been well established as they are precursors for several chemicals. A specially adapted electrolyte composition is established by adjusting solvent ratio and LiTFSI concentration in a TXG:DOL solvent blend. The obtained electrolytes show long cycle life as well as high coulombic efficiencies without the use of LiNO3, a component leading normally to cell inflation and safety issues. In addition, a successful evaluation in a multilayer Li-S-pouch cell was performed. The electrolytes were thoroughly characterized, and their sulfur conversion mechanism is discussed. [ABSTRACT FROM AUTHOR]

A novel voltammetric platform based on pencil graphite electrode (PGE) modification has been proposed, containing bimetallic (NiFe) Prussian blue analogue nanopolygons decorated with electro-polymerized glyoxal polymer nanocomposites (p-DPG NCs@NiFe PBA Ns/PGE). Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and square wave voltammetry (SWV) were utilized to investigate the electrochemical performance of the proposed sensor. The analytical response of p-DPG NCs@NiFe PBA Ns/PGE was evaluated through the quantity of amisulpride (AMS), one of the most common antipsychotic drugs. Under the optimized experimental and instrumental conditions, the method showed linearity over the range from 0.5 to 15 × 10−8 mol L−1 with a good correlation coefficient (R = 0.9995) and a low detection limit (LOD) reached, 1.5 nmol L−1, with excellent relative standard deviation for human plasma and urine samples. The interference effect of some potentially interfering substances was negligible, and the sensing platform demonstrated an outstanding reproducibility, stability, and reusability. As a first trial, the proposed electrode aimed to shed light on the AMS oxidation mechanism, where the oxidation mechanism was monitored and elucidated using the FTIR technique. It was also found that the prepared p-DPG NCs@NiFe PBA Ns/PGE platform had promising applications for the simultaneous determination of AMS in the presence of some co-administered COVID-19 drugs, which could be attributed to the large active surface area, and high conductivity of bimetallic nanopolygons. [ABSTRACT FROM AUTHOR]

Acid and alkali pretreatment are the most commonly employed strategy in a lignocellulosic biorefinery. The main objective of the study was to evaluate the chemical implications of acid and alkali on the lignin structure and subsequently on the adhesive performance. The study also aimed to investigate the effect of complete replacement of phenol and formaldehyde in the commercial wood adhesive with phenolic lignin and glyoxal, respectively. The phenolic lignin was derived from the two differentially pretreated sugarcane bagasse, i.e., acid and alkali. The isolated lignin was characterized and utilized for the synthesis of lignin-based glyoxal resin. The resins were comparatively evaluated for their mechanical properties as wood adhesives. Adhesives derived from acid pretreated sugarcane bagasse were found to be superior to lignin derived from alkali pretreated sugarcane bagasse in terms of mechanical properties and shear strength. [ABSTRACT FROM AUTHOR]

Concise and attractive synthesis of a new class of pyrimido[5,4‐e][1,3]oxazine diones was attained with impressive yields, using a convenient and elegant condensation reaction between thiobarbituric acid and aryl glyoxals in the presence of N‐methyl urea in EtOH under thermal and thermal microwave‐assisted conditions. Some specific merits of the current procedure, include the availability of the starting materials, low reaction time, high reaction yield, operational simplicity, no harmful by‐products, and the high purity of the isolated products. Structures of all the freshly synthesized products have been deduced by their FT‐IR, 1H‐NMR, 13C‐NMR, and elemental analysis. [ABSTRACT FROM AUTHOR]

Background/Aims: Trazodone is a selective serotonin reuptake inhibitor; however, other mechanisms of the drug's anti-depressive properties have also been postulated. Hence, the aim of the study was to perform a systematic review and assess antiglycoxidative properties of trazodone in in vitro models. Methods: Trazodone's scavenging and chelating properties were measured with spectrophotometric method. The impact of the drug on carbonyl/ oxidative stress was marked in the bovine serum albumin (BSA) model where sugars (glucose, fructose, galactose, ribose) and aldehydes (glyoxal and methylglyoxal) were used as glycation agents. Aminoguanidine and N-acetylcysteine (NAC) were applied as reference glycation/ free radical inhibitors. Glycation biomarkers (kynurenine, N-formylkynurenine, dityrosine as well as advanced glycation end products contents) were assessed spectrofluorometrically. Concentrations of oxidation parameters (total thiols (TTs), protein carbonyls (PCs) and also advanced oxidation protein products (AOPPs) levels) were determined spectrophotometrically. Results: We demonstrated that trazodone poorly scavenged radicals (hydroxyl radical, nitric oxide, hydrogen peroxide and 2,2-diphenyl-1-picrylhydrazyl radical) and showed low ferrous ion chelating, unlike aminoguanidine and NAC. Sugars/aldehydes caused enhancement of glycation parameters, as well as a decrease of TTs and an increase of PCs and AOPPs levels compared to BSA incubated alone. Trazodone did not reduce oxidation parameters to the baseline (BSA) and significantly exacerbated glycation markers in comparison with both BSA and BSA+glycators. The content of glycation products was markedly lower in aminoguanidine and NAC than in trazodone. The molecular docking of trazodone to BSA revealed its very low affinity, which may indicate non-specific binding of trazodone, facilitating the attachment of glycation factors. Conclusion: According to our findings, it may be concluded that trazodone poorly counteracts oxidation and intensifies glycation in vitro. A possible mechanism for antiglycoxidative effect of trazodone in vivo may be the enhancement of the body's adaptive response, as indicated by the results of our systematic review. [ABSTRACT FROM AUTHOR]

The changes in protein degradation (TCA-soluble peptides), Schiff bases, dicarbonyl compounds (glyoxal-GO, methylglyoxal-MGO) and two typical advanced glycation end-products (AGEs) including Nε-carboxymethyllysine (CML), Nε-carboxyethyllysine (CEL) levels in ground pork supplemented with sucrose (4.0%) were investigated under nine freeze–thaw cycles and subsequent heating (100 °C/30 min). It was found that increase in freeze–thaw cycles promoted protein degradation and oxidation. The addition of sucrose further promoted the production of TCA-soluble peptides, Schiff bases and CEL, but not significantly, ultimately leading to higher levels of TCA-soluble peptides, Schiff bases, GO, MGO, CML, and CEL in the ground pork with the addition of sucrose than in the blank groups by 4%, 9%, 214%, 180%, 3%, and 56%, respectively. Subsequent heating resulted in severe increase of Schiff bases but not TCA-soluble peptides. Contents of GO and MGO all decreased after heating, while contents of CML and CEL increased. [ABSTRACT FROM AUTHOR]

Glyoxal (CHOCHO) is a trace gas in the atmosphere, often used as an indicator of biogenic emissions. It is frequently compared to formaldehyde concentrations, which serve as indicators of anthropogenic emissions, to gain insights into the characteristics of the environmental source. This study employed broadband cavity-enhanced absorption spectroscopy to detect gaseous CHOCHO, methylglyoxal, and NO2. Two different detection methods are compared. Spectrograph and CCD Detection: This approach involves coupling the system to a spectrograph with a charge-coupled device (CCD) detector. It achieved a 1 min 1-σ detection limit of 2.5 × 108 molecules/cm3, or 10 parts per trillion (ppt). Methylglyoxal and NO2 achieved 1 min 1-σ detection limits of 34 ppt and 22 ppt, respectively. Interferometer and PMT Detection: In this method, an interferometer is used in conjunction with a photomultiplier tube (PMT) detector. It resulted in a 2 min 1-σ detection limit of 1.5 × 1010 molecules/cm3, or 600 ppt. The NO2 2 min 1-σ detection limit was determined to be 900 ppt. Concentrations of methylglyoxal were difficult to determine using this method, as they appeared to be below the detection limit of the instrument. This study discusses the advantages and limitations of each of these detection methods.

Biogenic volatile organic compounds (BVOC), which are mainly emitted from plants, are a major precursor for the formation of ground-level ozone (O3) and secondary organic aerosols (SOA). In the northern region of Thailand, 63.8% of the land area is covered by forests. Herein we investigated the effects of biogenic volatile organic compounds (BVOC) emitted from plants and anthropogenic NOx emissions on ground-level ozone (O3) and fine particulate matters (PM2.5) formation. The Weather Research and Forecasting Model coupled with Chemistry (WRF-Chem Model) was applied to simulate three scenarios including baseline, noBio and modiAntho simulations. The modeling results over the northern region of Thailand indicate that BVOC emissions over the northern region of Thailand contributed only 5.3%–5.6% of the total concentrations of PM2.5 and BVOC had a direct relationship to glyoxal and SOA of glyoxal. The comparison between the observed and the modeled isoprene over the study site showed an underestimation (3- to 4-folds) of the simulated concentrations during the study period (June and November 2021). In June, decreases in anthropogenic NOx emissions by 40% led to PM2.5 reductions (5.3%), which corresponded to a zero BVOC emission scenario. While higher PM2.5 reductions (5.6%) were found to be caused by anthropogenic NOx reductions in November, small increases in PM2.5 were observed over the area near a power plant located in Lampang Province. Therefore, both VOC and NOx emission controls may be necessary for areas near the lignite mine and power plant. Since the areas within the vicinity of the power plant were under VOC-limited regimes, while the other areas were determined to be NOx-limited.

Space‐borne observations are used to characterize the fate of formaldehyde and glyoxal in wildfire plumes. Their distribution measured by the Tropospheric Monitoring Instrument reveals striking differences between the two compounds near intense fires. In typical situations, the glyoxal‐to‐formaldehyde ratio is highest near the fire (∼0.1) and decreases downwind of the source area due to the larger contribution of pyrogenic emissions to the glyoxal abundance and to the longer lifetime of formaldehyde. However, a pronounced glyoxal depletion is detected above high‐level clouds, not seen for formaldehyde, likely due to processing in pyrocumulonimbus clouds generated by the fires. This depletion suggests glyoxal retention upon droplet freezing and/or its outgassing in hydrated form in the upper troposphere. The absence of a sizable loss of formaldehyde during convection indicates that its hydration in liquid droplets and subsequent outgassing as methanediol represent at most a minor sink of formaldehyde. Plain Language Summary: Wildfires have a strong impact on air quality and climate owing to their associated large emissions of aerosols and gases. For very intense events, the injected material can reach high altitudes, in particular when the fires induce formation of convective pyrocumulonimbus clouds. Using the high spatial resolution observations from the spaceborne Tropospheric Monitoring Instrument, we investigate the respective distributions of formaldehyde and glyoxal, two proxys for volatile organic compounds emissions, at close proximity of intense fire sources. Typically, the glyoxal signal is maximum near the fire source and decreases downwind, while the formaldehyde distribution is more extended and shows weaker spatial gradient. However, we have identified a significant glyoxal depletion, not seen for formaldehyde, in case of injection at high altitudes, typically above the freezing level, suggesting its retention in ice particles or its outgassing in a hydrated form. Key Points: Space observations of glyoxal‐to‐formaldehyde ratio typically show highest values near fires and decrease downwindA pronounced glyoxal depletion is identified above high‐level pyrocumulonimbus clouds generated by intense wildfiresGlyoxal depletion is likely due to retention in ice particles or outgassing as glyoxal hydrate when droplets reach the upper troposphere [ABSTRACT FROM AUTHOR]