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Environmentally persistent free radicals (EPFRs) play an important role in aerosol effects on air quality and public health, but their atmospheric abundance and sources are poorly understood. We measured EPFRs contained in PM2.5 collected in Fairbanks, Alaska, in winter 2022. We find that EPFR concentrations were enhanced during surface-based inversion and correlate strongly with incomplete combustion markers, including carbon monoxide and elemental carbon (R2 > 0.75). EPFRs exhibit moderately good correlations with PAHs, biomass burning organic aerosols, and potassium (R2 > 0.4). We also observe strong correlations of EPFRs with hydrocarbon-like organic aerosols, Fe and Ti (R2 > 0.6), and single-particle mass spectrometry measurements reveal internal mixing of PAHs, with potassium and iron. These results suggest that residential wood burning and vehicle tailpipes are major sources of EPFRs and nontailpipe emissions, such as brake wear and road dust, may contribute to the stabilization of EPFRs. Exposure to the observed EPFR concentrations (18 ± 12 pmol m-3) would be equivalent to smoking ∼0.4-1 cigarette daily. Very strong correlations (R2 > 0.8) of EPFR with hydroxyl radical formation in surrogate lung fluid indicate that exposure to EPFRs may induce oxidative stress in the human respiratory tract.

Electronic (e-) cigarette formulations containing nicotine salts from a range of organic acid conjugates and pH values have dominated the commercial market. The acids in the nicotine salt formulations may alter the redox environment in e-cigarettes, impacting free radical formation in e-cigarette aerosol. Here, the generation of aerosol mass and free radicals from a fourth-generation e-cigarette device was evaluated at 2 wt % nicotine salts (pH 7, 30:70 mixture propylene glycol to vegetable glycerin) across eight organic acids used in e-liquids: benzoic acid (BA), salicylic acid (SLA), lactic acid (LA), levulinic acid (LVA), succinic acid (SA), malic acid (MA), tartaric acid (TA), and citric acid (CA). Furthermore, 2 wt % BA nicotine salts were studied at the following nicotine to acid ratios: 1:2 (pH 4), 1:1 (pH 7), and 2:1 (pH 8), in comparison with freebase nicotine (pH 10). Radical yields were quantified by spin-trapping and electron paramagnetic resonance (EPR) spectroscopy. The EPR spectra of free radicals in the nicotine salt aerosol matched those generated from the Fenton reaction, which are primarily hydroxyl (OH) radicals and other reactive oxygen species (ROS). Although the aerosol mass formation was not significantly different for most of the tested nicotine salts and acid concentrations, notable ROS yields were observed only from BA, CA, and TA under the study conditions. The e-liquids with SLA, LA, LVA, SA, and MA produced less ROS than the 2 wt % freebase nicotine e-liquid, suggesting that organic acids may play dual roles in the production and scavenging of ROS. For BA nicotine salts, it was found that the ROS yield increased with a higher acid concentration (or a lower nicotine to acid ratio). The observation that BA nicotine salts produce the highest ROS yield in aerosol generated from a fourth-generation vape device, which increases with acid concentration, has important implications for ROS-mediated health outcomes that may be relevant to consumers, manufacturers, and regulatory agencies.

GaCH2, a free radical thought to play a role in the chemical vapor deposition of gallium-containing thin films and semiconductors, has been spectroscopically detected for the first time. The radical was produced in a pulsed discharge jet using a precursor mixture of trimethylgallium vapor in high pressure argon and studied by laser-induced fluorescence and wavelength resolved emission techniques. Partially rotationally resolved spectra of the hydrogenated and deuterated species were obtained, and they exhibit the nuclear statistical weight variations and subband structure expected for a 2A2–2B1 electronic transition. The measured spectroscopic quantities have been compared to our own ab initio calculations of the ground and excited state properties. The electronic spectrum of gallium methylene is similar to the corresponding spectrum of the aluminum methylene radical, which we reported in 2022. [ABSTRACT FROM AUTHOR]

C4F7N/CO2 gas mixtures have attracted extensive attention because of their excellent insulating properties and environmental friendliness. High electrical and thermal stability is an important indicator for evaluating their performance, but there have been few molecular dynamics studies of their decomposition mechanisms. In this study, using ReaxFF molecular dynamics simulations and quantum chemistry theory, the decomposition mechanism of a C4F7N/CO2 gas mixture and the effect of the O2 content on the decomposition of the mixture were simulated on the microscopic level. It was found that there are three main decomposition pathways of C4F7N molecules, of which the generation of C3F4N⋅ and CF3⋅ free radicals is the most likely to occur. COF2 is the main oxygen-containing product of the C4F7N/CO2 gas mixture, and its generation is significantly affected by the simulation time and temperature. COF2 can be regarded as the characteristic decomposition product of the C4F7N/CO2 gas mixture. The addition of O2 slightly promotes the decomposition of C4F7N, whereas the maximum decomposition rate of CO2 decreases by 0.3% and 1% after the addition of 2% and 8% O2, respectively. Relevant results of this research can provide a theoretical basis and guidance for research into the performance of C4F7N/CO2 gas mixtures and practical engineering applications of these mixtures in the future. [ABSTRACT FROM AUTHOR]

Absolute line strengths of several transitions in the ν1 fundamental band of the hydroxyl radical (OH) have been measured by simultaneous determination of hydrogen peroxide (H2O2) and OH upon laser photolysis of H2O2. Based on the well-known quantum yield for the generation of OH radicals in the 248-nm photolysis of H2O2, the line strength of the OH radicals can be accurately derived by adopting the line strength of the well-characterized transitions of H2O2 and analyzing the difference absorbance time traces of H2O2 and OH obtained upon laser photolysis. Employing a synchronized two-color dual-comb spectrometer, we measured high-resolution time-resolved absorption spectra of H2O2 near 7.9 µm and the OH radical near 2.9 µm, simultaneously, under varied conditions. In addition to the studies of the line strengths of the selected H2O2 and OH transitions, the kinetics of the reaction between OH and H2O2 were investigated. A pressure-independent rate coefficient kOH+H2O2 was determined to be [1.97 (+0.10/−0.15)] × 10−12 cm3 molecule−1 s−1 at 296 K and compared with other experimental results. By carefully analyzing both high-resolution spectra and temporal absorbance profiles of H2O2 and OH, the uncertainty of the obtained OH line strengths can be achieved down to <10% in this work. Moreover, the proposed two-color time-resolved dual-comb spectroscopy provides a new approach for directly determining the line strengths of transient free radicals and holds promise for investigations on their self-reaction kinetics as well as radical–radical reactions. [ABSTRACT FROM AUTHOR]

Oxidative species, generated endogenously via metabolism or from exogenous sources, play crucial roles in the body. At low levels, these species support immune functions by participating in phagocytosis. They also aid in cellular signaling and contribute to vasomodulation. However, when the levels of oxidative species exceed the body's antioxidant capacity to neutralize them, oxidative stress occurs. This stress can damage cellular macromolecules such as lipids, DNA, RNA, and proteins, driving the pathogenesis of diseases and aging through the progressive deterioration of physiological functions and cellular structures. Therefore, the body's ability to manage oxidative stress and maintain it at optimal levels is essential for overall health. Understanding the fundamentals of oxidative stress, along with its reliable quantification, can enable consistency and comparability in clinical practice across various diseases. While direct quantification of oxidant species in the body would be ideal for assessing oxidative stress, it is not feasible due to their high reactivity, short half-life, and the challenges of quantification using conventional techniques. Alternatively, quantifying lipid peroxidation, damage products of nucleic acids and proteins, as well as endogenous and exogenous antioxidants, serves as appropriate markers for indicating the degree of oxidative stress in the body. Along with the conventional oxidative stress markers, this review also discusses the role of novel markers, focusing on their biological samples and detection techniques. Effective quantification of oxidative stress may enhance the understanding of this phenomenon, aiding in the maintenance of cellular integrity, prevention of ageassociated diseases, and promotion of longevity. [ABSTRACT FROM AUTHOR]

The implementation of Salix psammophila sand barriers measures constitutes a crucial element in desertification control, providing a solid theoretical foundation for the future application and pretreatment of sand barriers in production practices. To address the specific damage types predominant in desert environments, we executed simulations of ultraviolet irradiation and rainfall phenomena on mechanical sand barriers in sandy areas and also inspected the variations in chemical properties during accelerated aging processes. The findings unequivocally demonstrate that: (1) The synergistic impact of ultraviolet irradiation and water accelerated the deformation and fracturing of the S.psammophila sand barriers, thereby causing a partial degradation of its chemical properties and conspicuous lignin oxidation; (2) The fissure of the sand barrier deepened, resulting in structural alterations. The existence of water expedites the degradation process of S.psammophila sand barriers under ultraviolet irradiation. (3)With respect to the binding form of C atoms, the carbon atoms at S.psammophila sand barriers were highly oxidized after 576 hours of accelerated aging. The components of C2 (C-O) and C3 (C=O) rising to 40.16% and 12.24% respectively, while the components of C1 (C-C) declined to 47.60%. The amount of hydroxyl (O-C-O), carbonyl (C=O), and carboxyl (O-C=O) groups increases in line with the expansion of the contact area between the sand barrier structure and ultraviolet irradiation as well as water. More free radical substances are generated, thereby causing the chemical binding properties to tend to be more stable. In summary, Ultraviolet irradiation and water change are the primary factors influencing the degradation of S.psammophila sand barriers material structure and properties. In future desertification control, it is imperative to focus on enhancing the longevity of sand barriers by ensuring their waterproofing capabilities and resistance to ultraviolet irradiation. [ABSTRACT FROM AUTHOR]

The current study explores the effects of microwave treatment at varying wattage and durations on the phytoconstituents, antioxidant status, anti-nutritional factors (ANFs), and metabolite profiles of de-oiled rice bran. The total phenolics and flavonoids showed both increases and decreases depending on specific microwave parameters, while flavonol content consistently increased across all treated groups compared to the control. The DPPH and ABTS free radical scavenging activity, total antioxidant capacity, FRAP, CUPRAC, metal chelating activity, and ascorbic acid content were enhanced in most of the microwaved samples; however, longer microwave exposure at higher wattage led to their reduction. A treatment-specific decrease in ANFs, including condensed tannins, oxalates, and phytates, was observed. HRMS-based untargeted metabolomics identified a diverse range of primary and secondary metabolites, which clustered in a group-specific manner, indicating notable group-wise metabolite variations. Analysis of discriminating metabolites revealed no significant differences in the overall levels of phenolics, flavonoids, vitamins and cofactors, sugars, amino acids, terpenoids, fatty acids, and their derivatives among the treated groups compared to the control; however, several individual metabolites within these metabolite classes differed significantly. These findings suggest that optimized microwaving of de-oiled rice bran can enhance phytochemicals and antioxidants while improving the metabolite profile. [ABSTRACT FROM AUTHOR]

AbstractThe synthesis of a novel large type double-layered cyclophanes has been successfully accomplished by free radical coupling reaction with the bis(N-alkylene benzothiazolium) dibromide salts as their important synthetic intermediates. The structures of the two-layered cyclophanes and the synthetic intermediates have been elucidated based on the NMR data and X-ray structural analysis, respectively. The two-layered cyclophanes consist of two different geometries, anti-two cyclic lactam amide rings inside and two bridges of disulfide bonds outside, which are unique and novel structures. Their physical properties were investigated by UV–Vis and redox potential, too. [ABSTRACT FROM AUTHOR]

When the level of reactive oxygen species (ROS) increases abnormally in the body, it damages tissue cells and is closely related to the occurrence of various chronic diseases. Antioxidant peptides (APs) are a class of active short peptides with antioxidant capacity, which have great research value. In this paper, two APs were designed and synthesized based on the structural features of APs: CHIWM (AP1) and CHCPWM (AP2). The reactive sites and activities of APs were analyzed using the quantum chemical density functional theory (DFT) method. The reactive sites are all located in the indolyl heterocycle of tryptophan residues, among which AP1 has a smaller energy gap and single point energy. Multiple free radical scavenging assays showed that AP1 and AP2 had stronger antioxidant activity than the positive control, glutathione (GSH). For scavenging DPPH free radicals, the IC50s values were 0.613 mg/mL and 0.606 mg/mL, respectively. In cellular assays, both AP1 and AP2 were able to scavenge ROS in the cells and attenuate cellular damage. In conclusion, AP1 and AP2 designed in this paper have good antioxidant activity and have the potential to be applied in the treatment of chronic diseases caused by cellular oxidative damage. [ABSTRACT FROM AUTHOR]

As one of the mainstream biodegradable materials, poly(butylene adipate-co-terephthalate) (PBAT) foams offer a sustainable alternative to traditional plastic foams, effectively reducing environmental pollution. However, the high cost and poor mechanical performance of PBAT foams impede their practical application. Herein, the glycidyl methacrylate-grafted biomass lignin (GML) was used to produce a PBAT/GML composite foam with good foaming performance and mechanical properties at high lignin-filling amounts by twin-screw melting free radical polymerization and supercritical CO2 foaming process. The compatibility of GML in the PBAT matrix was improved due to the formation of ester bonds in modified lignin, endowing the PBAT/GML (PGML) composite foam with exceptional foaming performance. Additionally, the mechanical properties of PGML composite foam were remarkably enhanced due to the introduction of the abundant aromatic structures of GML and the construction of a stable covalent crosslinking network. The compressive strengths and compression modulus of the PGML foam were improved by 2.53 times and 2.47 times, while its bending strength and bending modulus were improved by 1.27 times and 3.92 times compared to the neat PBAT. This research affords a new strategy for developing low-cost biodegradable biomass PBAT/lignin composite foam materials with good foaming performance and mechanical properties. [ABSTRACT FROM AUTHOR]

Increased intramitochondrial free iron is a key feature of various liver diseases, leading to oxidative stress, mitochondrial dysfunction, and liver damage. Polydatin is a polyphenol with a hepatoprotective effect, which has been attributed to its ability to enhance mitochondrial oxidative metabolism and antioxidant defenses, thereby inhibiting reactive oxygen species (ROS) dependent cellular damage processes and liver diseases. However, it has not been explored whether polydatin is able to exert its effects by protecting the phospholipid cardiolipin against damage from excess iron. Cardiolipin maintains the integrity and function of electron transport chain (ETC) complexes and keeps cytochrome c bound to mitochondria, avoiding uncontrolled apoptosis. Therefore, the effect of polydatin on oxidative lipid damage, ETC activity, cytochrome levels, and ROS production was explored in iron-exposed rat liver mitochondria. Fe2+ increased lipid peroxidation, decreased cardiolipin and cytochromes c + c1 and aa3 levels, inhibited ETC complex activities, and dramatically increased ROS production. Preincubation with polydatin prevented all these effects to a variable degree. These results suggest that the hepatoprotective mechanism of polydatin involves the attenuation of free radical production by iron, which enhances cardiolipin levels by counteracting membrane lipid peroxidation. This prevents the loss of cytochromes, improves ETC function, and decreases mitochondrial ROS production. [ABSTRACT FROM AUTHOR]

The exhaustion of conventional light oils necessitates the shift towards unconventional sources such as biomass, heavy oil, oil shale, and coal. Non-catalytic thermal cracking by a free radical mechanism is at the heart of the upgrading, prior to refining into valuable products. However, thermal pyrolysis is hindered by the formation of asphaltenes, precursors to coke, limiting cracking, causing equipment fouling, and reducing product stability. Free radicals are inherently present in heavy fractions and are generated during thermal processes. This makes these reactive intermediates central to understanding these mechanisms and limiting coking. Electron spin resonance (ESR) spectroscopy facilitates such mechanistic studies. Over the past decade, there has been no review of using in-situ ESR for studying thermal processes. This work begins with a brief description of free radicals' chain reactions during thermal reactions and the wealth of information ESR provides. We then critically review the literature that uses ESR for mechanistic studies in thermal pyrolysis of biomass, heavy oil, shales, and coal. We conclude that limited literature exist, and more investigations are necessary. The key findings from existing literature are summarized to know the current state of knowledge. We also explicitly highlight the research gaps. [ABSTRACT FROM AUTHOR]

Alternating copolymers are crucial for diverse applications. While dispersity (Ð, also known as molecular weight distribution, MWD) influences the properties of polymers, achieving low dispersities in alternating copolymers poses a notable challenge via free radical polymerizations (FRPs). In this work, we demonstrated an unexpected discovery that dispersities are affected by the participation of charge transfer complexes (CTCs) formed between monomer pairs during free radical alternating copolymerization, which have inspired the successful synthesis of various alternating copolymers with low dispersities (>30 examples, Ð=1.13–1.39) under visible‐light irradiation. The synthetic method is compatible with binary, ternary and quaternary alternating copolymerizations and is expandable for both fluorinated and non‐fluorinated monomer pairs. DFT calculations combined with model experiments indicated that CTC‐absent reaction exhibits higher propagation rates and affords fewer radical terminations, which could contribute to low dispersities. Based on the integration of Monte Carlo simulation and Bayesian optimization, we established the relationship map between FRP parameter space and dispersity, further suggested the correlation between low dispersities and higher propagation rates. Our research sheds light on dispersity control via FRPs and creates a novel platform to investigate polymer dispersity through machine learning. [ABSTRACT FROM AUTHOR]

The (BiO)4CO3(OH)2/BiOBr heterojunction was developed by a facile hydrothermal process using polyhedral (BiO)4CO3(OH)2 as the precursor and HBr as the etching agent. BiOBr nanosheets were vertically and orderly grown on the surface of (BiO)4CO3(OH)2, and the obtained (BiO)4CO3(OH)2/BiOBr heterojunction exhibits outstanding photocatalytic performance to degrade 50 mg L−1 of Cr(VI) and 30 mg L−1 of TC in 25 and 20 min, respectively, under simulated sunlight. The enhanced photocatalytic performance is the synergistic effect of the two factors: the unique hierarchical structure can effectively utilize light, and the suitable position of the band edge is conducive to the construction of a Z-scheme heterostructure. The free radical capture confirms that superoxide free radicals (˙O2−) and hydroxyl radicals (˙OH) are the major active agents during photocatalysis. Based on the transient photocurrent response and electrochemical impedance measurements, the (BiO)4CO3(OH)2/BiOBr heterostructure shows excellent separation efficiency of the photogenerated electron–hole pairs. This finding will inspire many researchers to develop novel high-performance photocatalysts for degrading harmful and toxic pollutants and remediating environmental pollution. [ABSTRACT FROM AUTHOR]

Although the fundamental configuration (tetrahedron-type and capsule-type) of Zr-MOCs is well understood, the synthesis of amino-functionalized Zr-based capsule (denoted as ZrC-1-NH2) based on 2-aminoterephthalic acid remains a considerable challenge. Fortunately, we obtained single crystals under solvothermal conditions and further achieved the rapid synthesis of ZrC-1-NH2 with pure phase and high yield using a microwave-assisted solvothermal method. In addition, ZrC-1-NH2 was utilized as a photocatalyst to perform the degradation of tetracycline (TC) in water. The degradation efficiency of 92.3% was achieved at the optimal conditions, and the main active free radical was determined as ·O2− according to the trapping agent experiment and EPR results. Furthermore, the possible degradation pathway of TC was proposed. [ABSTRACT FROM AUTHOR]

After cerebral ischemia, the brain encounters noxious stimuli that result in a dysfunctional balance between the production and elimination of reactive oxygen species, which in turn cause damage to cellular components. Oxidative stress may activate the inflammatory response, promoting apoptosis, autophagy, etc. Flavonoids are present in a wide range of foods and have antioxidant, anti-inflammatory, antimutagenic and anticancer properties. Dietary flavonoid intake have beneficial effects against ischemic stroke. Dietary flavonoids can significantly reduce the risk of ischemic stroke and improve its prognosis by directly scavenging free radicals, regulating redox balance, and modulating signaling pathways and gene expression to counteract the cellular damage of brain caused by oxidative stress after ischemic stroke. Therefore, this review summarizes the effect of dietary flavonoids against oxidative stress on ischemic stroke. [ABSTRACT FROM AUTHOR]

Myracrodruon urundeuva, popularly known as 'aroeira-do-sertão', a large tree, with a tall trunk. Belonging to the Anacardiaceae family, it occurs in the 'caatinga' and dry forests of Brazil, from Ceará to the states of Paraná and Mato Grosso do Sul. The present study aimed to analyse the whitening and antioxidant activities of the aqueous extract of the leaves of Myracrodruon urundeuva (AELMU). Inhibition of the tyrosinase enzyme, as well as its copper chelating capacity and antioxidant effect were evaluated. The AELMU (at 2000 µg/mL) showed excellent inhibitory action (83.76%) on tyrosinase by chelating the copper ion while kojic acid at the same concentration inhibited 97.81%. Moreover, the extract displayed important antioxidant activity (inhibited 76,46% of the 2,2-diphenyl-1-picrylhydrazyl radical - DPPH; 49,59% of thiobarbituric acid reactive substances and 51,07% of the hydroxyl radical). Thus, the extract under study is promising for use in cosmetics, given its multifactorial action. [ABSTRACT FROM AUTHOR]

Diblock copolymers of phenyl methacrylate (PMA) and butyl methacrylate (BMA) were synthesized using dual-wavelength photopolymerization with a bifunctional photoinitiator 2-(4-(2-hydroxy-2-methylpropanoyl)phenoxy)ethyl(E)-3-(1-methyl-1H-pyrrol-2-yl)acrylate (PAA-2959). [ABSTRACT FROM AUTHOR]

In this study, two characteristics of boehmite nanoparticles (BNs) were used to improve the dynamic‐mechanical properties of pure unsaturated polyester resin (Neat UP). (1) Boehmite's ability to target free radical control in the radical curing reaction of UP resin, and (2) adsorption of alkyd chains and creation of attractive interactions with the resin network. X‐ray diffraction (XRD), Fourier‐transform infrared spectroscopy (FT‐IR), and field‐emission scanning electron microscopy (FESEM) analysis were used to identify the synthesis of particles. The results of FESEM analysis showed that the average particle size was 80–100 nm. TGA was used to investigate the thermal properties of the Neat UP and UP resin containing 0.3 wt% BNs (UP 0.3 BNs). The results of the dynamic‐mechanical analysis showed that the elastic modulus of the UP 0.3 BNs composite increased by 42% compared to the Neat UP. To investigate the significant increase observed in the dynamic‐mechanical properties, the curing kinetics were investigated by differential scanning calorimetry (DSC). Investigating the activation energy in terms of the conversion degree showed earlier dominance of the diffusion phenomenon in the UP 0.3 BNs composite. Investigating the diffusion factors provided by Vyazovkin–Sbirrazzouli showed a significant decrease in K and ED in the UP 0.3 BNs composite (−10.5, 19 kJ/mol) compared to the Neat UP resin (−9.5, 40 kJ/mol). Highlights: Targeted control of free radicals increases network regularity of the UP/BNs.Impressive improvement of mechanical properties of UP/BNs compared to Neat UP.Increasing diffusion phenomenon dominance of UP/BNs system compared to Neat UP. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development 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.)

Copyright of Food Research & Development is the property of Food Research & Development 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.)

Inflammatory infiltration of synovial M1 macrophages, high levels of ROS, and NO exacerbate osteoarthritis (OA) progression. The PdZn/CoSA‐NC nanozymes, which are highly ordered PdZn intermetallic nanoparticles loaded with Co single atom N‐doped carbon‐rich in multi‐level pores, in an attempt to serve as SOD and CAT mimicking nanozymes for OA therapy is designed. The PdZn/CoSA‐NC nanozymes' high electron transfer and dual active site sufficient exposure enhances free radical adsorption and lower reaction energies, accelerating SOD‐like, CAT‐like, and GPx‐like catalyzed reactions, outperforming CoSA‐NC and PdZn/NC alone. Furthermore, PdZn/CoSA‐NC nanozymes exhibit favorable biocompatibility, reduce synovial macrophage oxidative stress in OA, alleviate hypoxia, restore mitochondrial function, regulate energy metabolism, increase antioxidant factors, and reduce inflammatory factors, thus effectively mitigating the progression of OA. Mechanistically, PdZn/CoSA‐NC nanozymes downregulate M1‐type phenotypic markers like IL‐1β by regulating purine metabolism. The PdZn/CoSA‐NC nanozymes offer a novel approach to treating oxidative stress‐related inflammatory diseases. [ABSTRACT FROM AUTHOR]

ABSTRACT Hyaluronic acid (HA) is extensively utilized in biomedical applications, and its functionality can be enhanced by introducing aldehyde groups (─CHO) through oxidation. In this study, cold atmospheric plasma (CAP) was used to treat aqueous HA solutions, resulting in the formation of plasma‐modified HA (PMHA) containing ─CHO groups. The free radicals generated from interactions between water molecules and CAP particles reacted with HA, leading to the oxidation of hydroxyl groups into ─CHO and the cleavage of glycosidic bonds, causing molecular depolymerization. The PMHA was then used to synthesize hydrogels in combination with carboxymethyl chitosan and ɛ‐polylysine. This study presents an effective approach for generating HA with aldehyde functionalities and offers insights into the interaction between CAP and polysaccharides. [ABSTRACT FROM AUTHOR]

We report on the synthesis, structure and reactivity of [{NCNMe4}Sb(C6H2-tBu2-3,5-O-4)] (3), an organoantimony(III)-oxyaryl species obtained upon Csp2–H bond activation in a phenolate ligand and stabilised by the monoanionic pincer {NCNMe4}−. The mechanism leading to the formation of 3 is highly sensitive to steric considerations. It was probed experimentally and by DFT calculations, and a number of intermediates and related complexes were identified. All data agree with successive heterolytic bond cleaving and bond forming processes involving charged species, rather than a pathway involving free radicals as previously exemplified with congeneric bismuth species. The nucleophilic behaviour of the oxyaryl ligand in 3, a complex that features both zwitterionic and quinoidal attributes, was illustrated in derivatisation reactions. In particular, insertion of CS2 in the Sb–Coxyaryl bond generates [{NCNMe4}Sb(S2C-C6H2-tBu2-3,5-O-4)]. [ABSTRACT FROM AUTHOR]

In this article, a CRET-based chemiluminescent sensor was developed for ascorbic acid detection. Au/Pt@Cu2O/CuO NPs with peroxidase activity were prepared to catalyse the decomposition of H2O2 to produce free radicals, which led to the enhancement of the chemiluminescence (CL) signal, and the CRET between luminol and MnO2 NSs was able to take place and the CL signal was reduced; the presence of ascorbic acid would reduce MnO2 NSs, which was able to weaken the energy transfer between luminol and MnO2 NSs and restored the CL signal. Under the optimal experimental conditions, the detection range of ascorbic acid was 1–1000 μM, and the LOD was 0.35 μM. The method is sensitive and has a wide linear range, and is expected to be applied to the detection of ascorbic acid in more complex environments. [ABSTRACT FROM AUTHOR]

5-Lipoxygenase (5-LOX) is a key enzyme involved in the biosynthesis of pro-inflammatory leukotrienes, leading to asthma. Developing potent 5-LOX inhibitors are highly attractive. In this research the previously synthesized isoxazole derivatives has been investigated against 5-LOX inhibitory and antioxidant in vitro assay. The compound 3 caused concentration dependent inhibition of 5-LOX with overall IC50 value of 8.47 μM. The investigated compounds C5 also exhibited good 5-LOX inhibitory effect. The IC50 demonstrated for C5 was 10.48. Among the 10 synthesized compounds, the potential 5-LOX inhibitory effect was reported for C6. The most potent compound which showed excellent free radical scavenging effect was C3 having IC50 value of 10.96 μM. The next most potent antioxidant activity was reported for C5 which non-significantly showed free radical scavenging effect. The IC50 value observed for C5 was 13.12 μM. Compound C6 also showed potent dose dependent antioxidant effect with IC50 value of 18.87 μM having percent inhibition of 91.63±0.55, 88.45±0.49, 83.53±0.45, 78.42±0.66 and 73.72±0.64 at concentration 1000–62.5 μg/mL respectively. Among the tested compounds, C6 was found most potent which showed significant 5-LOX percent inhibition assay and also reported the minimum IC50 value comparable to the reference drug. The in vitro 5-LOX enzymes inhibition assays of C5 and C3 also showed excellent percent inhibition and good potency next to C6. We concluded that amongst the investigated designed molecules the C3 was found best potent and showed significant dose dependent antioxidant activity against DPPH screening. The IC50 value reported for C3 was found good as compared to standard drug. Moreover, C5 and C6 also showed excellent free radical scavenging effect against DPPH assay. Computational methods have also been employed to explore the probable interaction model of inhibitors and enzyme active sites, and also to correlate the results of in silico and in vitro studies. [ABSTRACT FROM AUTHOR]

Turbinaria ornata, Polycladia myrica, and Padina pavonica is a perennial Mediterranean-native seaweed that is commonly used for mass display. The principal aims of this reconnaissance were the isolation of various compounds from methanolic seaweeds extraction and screening the potential effect as antibacterial, and antioxidant. The micro-dilution method was used to measure antibacterial activity. Gas chromatography-mass spectrophotometry (GC. Mass) abused to analyze the chemical components of the methanolic seaweed extract. The existence of 19 secondary metabolites was discovered using GC–MS analysis: 8 different compounds for each seaweed's species. Among these bioactive compounds, 4 compounds from P. pavonica extract showed the binding affinity and ability to react with Beta-ketoacyl synthase (PDB ID 1EK4) of Escherichia coli. The phytocompounds' drug-like and poisonous characteristics were predicted. Auto Dock was used to examine the ligand receptor complexes' binding strength. T. ornate and P. pavonica had the highest activity against K. pneumonia, with 22.50 mm (0.78 µg/ml) and 22.23 mm (5.10 µg/ml) obtained, respectively. In a concentration-dependent manner, the extract components demonstrated substantial antioxidant activity. P. pavonica had the highest scavenging activity (78.00%, IC50 = 6.35 µg/ml), while ascorbic acid had a 96.45% scavenging impact. Because the chemicals bind to the Lipinski Ro5, they have drug-like characteristics. The compounds had no hepatotoxic effects. P. pavonica extract has the prospect of being used as a source of medicinal drug-like chemicals. The docking investigation found a strong correlation between the experimental results and the docking results. Finally, brown seaweed extract, particularly P. pavonica extract, demonstrated strong antibacterial, antioxidant, and free radical scavenging properties. [ABSTRACT FROM AUTHOR]

Background: In people with type 1 diabetes mellitus, free radical activity is a major contributor to vascular problems. However, there is a dearth of information on vascular consequences in type 2 diabetes mellitus. Objectives: This research evaluated the free radical activity of individuals with type 2 diabetes who had hypertension to those who did not. Supplies and Procedures: Fifty type 2 diabetes outpatients had their blood levels of the lipid peroxidation product MDA (malondialdehyde), the free radical scavenger SOD (superoxide dismutase), and NO (nitric oxide) measured. The diabetic outpatients without hypertension were considered the controls. Result: Among 50 patients thus studied 18 were hypertensive. The concentration (median (range)) of both SOD (20.31(5.33-26.64) vs. 16.65(6.66-22.64) U/dl; p< 0.05) and NO (19.54 (11.40-37.07) vs.20.40 (15.69-35.65) U/dl; p< 0.05) were reduced in the hypertensive group. Similarly, concentration (median (range) of MDA (354(231-718) vs. 390(256-666)lmoles/dl; p< 0.01 were increased in thehypertensive group.. Conclusion: In comparison to healthy controls, we concluded that our study shows a considerable increase in free radical activity in Type II diabetes patients. [ABSTRACT FROM AUTHOR]

The aging process is influenced by the accumulation of both beneficial and harmful factors in the external environment. While extensive literature has explored the health benefits of short-term forest bathing, the potential for long-term exposure to forests to delay the aging process remains unclear. This study aimed to investigate the impact of prolonged urban forest contact on aging using a murine model. Forty male Specified Pathogen Free degree Kunming mice (6 weeks old, average weight 30.44 ± 0.91 g) were subjected to continuous subcutaneous injection of D-galactose in an urban environment and an urban forest environment to simulate an accelerated aging process lasting six weeks. Results showed that compared to urban environment, mice living in the forest environment exhibited significantly increased levels of serum oxidases CAT, GSH-Px, and SOD, as well as decreased levels of oxidative products H2O2 and MDA. These findings suggest that long-term forest living enhances serum Nrf2 expression, downstream oxidase activity, total antioxidant capacity, and resistance to free radicals and oxidative products, thus delaying the aging process. This study offers valuable insights into the potential health benefits of long-term forest living, which may play a role in delaying the aging process in humans. [ABSTRACT FROM AUTHOR]

Context: An inclusion complex between 2,2′-azobis(2-methylpropionamidine) dihydrochloride (AAPH), a widely employed azocompound, and cucurbit[7]util (CB[7]), has shown an increased yield of radicals derived from the homolytic cleavage of the azo bond. Aimed to get insights about the formation of complexes and their effect on the yield of radicals production, complexes of CB[7] with seven azocompounds were studied by computational methods. Molecular electrostatic surfaces and structural analysis showed that the inclusion of symmetrical azocompounds inside of CB[7] depends mainly on the charge density and position of the functional groups at the main chain of the azoderivative. Analysis of non-covalent interactions and thermodynamic outcomes revealed that positively charged azocompounds with amidinium or imidazolium groups presented strong favorable interactions (multiple hydrogen bonds) with the oxygens of CB[7] portals. Additionally, carbon-centered radicals generated from the complexes (azocompounds@CB[7]) were corroborated using the electron localization function (ELF). Results evidenced that the strength of the interactions and the level of inclusion (partial or complete) between the azocompound and CB[7] determined the final orientation of the radicals (located out- or inside of the CB[7] cavity). Obtained results could be employed to design new supramolecular systems based on the properties of azocomplound@CB[7] complexes for new scientific or industrial applications. Methods: First-principles calculations at B3LYP-D3BJ/6-311g(d,p) level theory in the gas phase and in solvent (PCM, water) were performed in Gaussian 16 software package. The dispersion energy correction was included through the Grimme's dispersion with Becke-Johnson damping D3(BJ). Thermodynamical data and the minimum character of all structures were obtained from vibrational frequency calculations. NBO, Multiwfn, Chemcraft, and NCIPLOT software were used to perform population analysis, analyze outcomes, visualize data, and display non-covalent interactions respectively. [ABSTRACT FROM AUTHOR]

Background: Environmentally persistent free radicals (EPFRs) are generated in the combustion processes of solid waste and can cause adverse influences on human health, especially lung diseases. Lung cancer is one of the most serious malignancies in recent years, which the global deaths rate is about 1.6 million every year. Methods and Results: In this study, we verified that ZnO/MCB EPFRs promote cell proliferation and migration, impedes cell apoptosis in lung cancer. Furthermore, we found that ZnO/MCB could influence the expression of miRNAs (miR-18a and miR-34a). In vivo, ZnO/MCB and ZnO EPFRs can reduce the weight and survival rate of BALB/c male mice more than that of BALB/c female mice. In the ZnO/MCB exposed group, male mice lung became even smaller, while the female mice the lung increased significantly. Taken together, our results provide evidence for assessing the potential health risks of persistent free radicals on fine particles. Conclusions: This study linked toxicity of EPFRs with miRNAs revealed the potential health hazard to human lung cancer. [ABSTRACT FROM AUTHOR]

Lubricin, secreted primarily by chondrocytes, plays a critical role in maintaining the function of the cartilage lubrication system. However, both external factors such as friction and internal factors like oxidative stress can disrupt this system, leading to osteoarthritis. Inspired by lubricin, a lubricating nanozyme, that is, Poly‐2‐acrylamide‐2‐methylpropanesulfonic acid sodium salt‐grafted aminofullerene, is developed to restore the cartilage lubrication system using an "In‐Out" strategy. The "Out" aspect involves reducing friction through a combination of hydration lubrication and ball‐bearing lubrication. Simultaneously, the "In" aspect aims to mitigate oxidative stress by reducing free radical, increasing autophagy, and improving the mitochondrial respiratory chain. This results in reduced chondrocyte senescence and increased lubricin production, enhancing the natural lubrication ability of cartilage. Transcriptome sequencing and Western blot results demonstrate that it enhances the functionality of mitochondrial respiratory chain complexes I, III, and V, thereby improving mitochondrial function in chondrocytes. In vitro and in vivo experiments show that the lubricating nanozymes reduce cartilage wear, improve chondrocyte senescence, and mitigate oxidative stress damage, thereby mitigating the progression of osteoarthritis. These findings provide novel insights into treating diseases associated with oxidative stress and frictional damage, such as osteoarthritis, and set the stage for future research and development of therapeutic interventions. [ABSTRACT FROM AUTHOR]

NH3 is a highly promising zero‐carbon fuel. In this paper, 19 important reactions involving NH3, NH2, and NH in the ammonia system are studied to better establish the combustion reaction mechanism of ammonia. These reactions encompass the reactions of NH3, NH2, and NH with free radicals and inorganic compounds such as O, H, OH, NO, H2O, and O2. Utilizing the transition state theory and Yao‐Lin method, energy barrier diagrams for these reactions are presented, and the harmonic and anharmonic rate constants are calculated over the temperature range from 300 to 4000 K. The calculation results reveal that, in most reactions, the harmonic rate constants exceed the anharmonic rate constants and the experimental results are closer to the anharmonic rate constants. Additionally, the kinetic and thermodynamic parameters are fitted. To summarize, most reactions are significantly influenced by the anharmonic effect. [ABSTRACT FROM AUTHOR]

In this work, two novel acridone-based photoinitiators were designed and synthesized for the free radical polymerization of acrylates with a light-emitting diode emitting at 405 nm. These acridone derivatives were employed as mono-component Type II photoinitiators and as multicomponent photoinitiating systems in the presence of an iodonium salt or an amine synergist (EDB) in which they achieved excellent polymerization initiating abilities and high final conversions of the acrylate group. Photoinitiation mechanisms through which reactive species are produced were investigated employing different complementary techniques including steady-state photolysis, steady-state fluorescence, cyclic voltammetry, UV–visible absorption spectroscopy, and electron spin resonance spectroscopy. Finally, these molecules were also used in the direct laser writing process for the fabrication of 3D objects. [ABSTRACT FROM AUTHOR]

Methamphetamine (METH) is a drug of abuse, which induces behavioral sensitization following repeated doses. Since METH alters blood pressure, in the present study we assessed whether systolic and diastolic blood pressure (SBP and DBP, respectively) are sensitized as well. In this context, we investigated whether alterations develop within A1/C1 neurons in the vasomotor center. C57Bl/6J male mice were administered METH (5 mg/kg, daily for 5 consecutive days). Blood pressure was measured by tail-cuff plethysmography. We found a sensitized response both to SBP and DBP, along with a significant decrease of catecholamine neurons within A1/C1 (both in the rostral and caudal ventrolateral medulla), while no changes were detected in glutamic acid decarboxylase. The decrease of catecholamine neurons was neither associated with the appearance of degeneration-related marker Fluoro-Jade B nor with altered expression of α-synuclein. Rather, it was associated with reduced free radicals and phospho-cJun and increased heat shock protein-70 and p62/sequestosome within A1/C1 cells. Blood pressure sensitization was not associated with altered arterial reactivity. These data indicate that reiterated METH administration may increase blood pressure persistently and may predispose to an increased cardiovascular response to METH. These data may be relevant to explain cardiovascular events following METH administration and stressful conditions. [ABSTRACT FROM AUTHOR]

In the present study, a dynamic Monte Carlo (MC) model is applied for predicting the dynamic evolution of monomer Droplet Size Distribution (DSD) and polymer Particle Size Distribution (PSD) within the presence of an inventive time step in the MC algorithm for both non‐reactive (liquid–liquid dispersion) and reactive systems. Besides, a combining approach as a second inventive strategy is introduced for implementing the MC simulation with a high number of droplets. An optimization process generated the dimensionless Model Parameters (MPs) and is applied to the MC simulation. The MC algorithm is validated with the experimental data from the literature. The novel time step can predict the dynamic evolution of monomer droplets and polymer particles in the reactive systems and diminish the time of the simulation. The combining approach is an excellent strategy for mixing the same or different number of droplets for decreasing time consumption of MC simulation. Extraordinary findings depicted the model's effectiveness and the validity of the time step and combining strategies. [ABSTRACT FROM AUTHOR]

Objective: To screen the synthesized analogues for their in vitro DPPH free radical scavenging activity. Due to their high efficacy and inexpensiveness compared to natural antioxidants, synthetic antioxidants are frequently used. The current work is primarily concerned with investigating the free radical scavenging activity of derivatives of thiobarbituric acid, based on the findings of the literature review. Methods: A series of N,N-diethylthiobarbiturates (I–XVII) were synthesized, and screened for their DPPH radical scavenging activity. Results and discussion: Limited structure-activity relationship has been established on the basis of different substituents and their varying positions. These synthetic compounds showed varying degree of inhibition in the range of IC50 values 20.28 ± 0.15 to 286.19 ± 0.16 μM. Limited structure-activity relationship was revealed that hydroxyl containing compounds (V) (IC50 = 20.28 ± 0.15 μM), (IV) (IC50 = 22.89 ± 0.19 μM), and (I) (IC50 = 26.34 ± 0.03 μM) showed comparable free radical scavenging activities with standard quercetin (IC50 = 16.96 ± 0.14 μM). Conclusions: The study indicates that N,N-diethylthiobarbiturate derivatives have the potential to be synthetic antioxidants since they have strong DPPH radical scavenging action. Additionally, molecules with hydroxyl substituting demonstrate efficacy that is comparable to that of the natural antioxidant quercetin. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to synthesize azine analogues of 1,2-diphenylethan-1-one while assessing their ability to scavenge free radicals with DPPH. In order to explore these compounds' potential as novel antioxidant agents with possible applications in the pharmaceutical, neutraceutical, and other industries, we synthesized them. Methods: The initial steps involved reacting 1,2-diphenylethan-1-one and additional amount of hydrated hydrazine in an ethanol solvent to produce the needed hydrazone, which paved the way for a two-step reaction that produced azine derivatives. Ultimately, a number of substituted aldehydes that are aromatic were heated by reflux condition, catalyzed by acetic acid with the obtained hydrazone to produce the azine derivatives in high yields. Results: These synthetic derivatives were screened for their anti-oxidant activity, compound (IIe) (IC50 = 24.13 ± 0.27 µM), (IIf) (IC50 = 29.11 ± 0.41 µM), and (IIg) (IC50 = 31.12 ± 0.44 µM) attributed the most excellent activity, however compound (IIc) and (IId) were found as significant DPPH free radical scavenging agents with IC50 values 46.21 ± 0.12 and 49.23 ± 0.54 µM, respectively while compound (IIa) and (IIb) displayed less anti-oxidant effect with IC50 values 55.11 ± 0.24 and 66.21 ± 0.12 µM. Conclusions: The study shows that the azine derivatives under investigation have promising potential as synthetic antioxidants due to their significant DPPH radical scavenging action. Furthermore, compounds containing electron-donating groups exhibit antioxidant activity comparable to that of ascorbic acid, an antioxidant that occurs naturally. These findings highlight the antioxidant qualities of the synthetic azine derivatives and suggest potential applications as medical treatments for oxidative stress-related illnesses. [ABSTRACT FROM AUTHOR]

Objective: The main objective of this work is to synthesize thiobarbituric acid based bis-Schiff base derivatives and to evaluate their ability to inhibit urease enzyme and DPPH free radical scavenging potential. Methods: Thiobarbituric acid derived bis-Schiff bases (IIIa–IIIi) were synthesized by treating 2,4-dihydroxybenzaldehyde and the starting moiety 1,3-diethyl-2-thiobarbituric acid in ethanol through refluxed followed by treating chloro ethyl acetate in DMF solvent. Subsequently, hydrazine hydrate was added to compound (II), yielding bis-hydrazide in better yield, which was further reacted via refluxed with benzaldehydes in ethanol, catalyzed by acetic acid to yield compounds (IIIa–IIIi) in excellent yields. Results: The resulting compounds were tested to inhibit urease enzyme and DPPH free radical scavenging activity. Among the series, compound (IIId) (IC50 = 16.11 ± 0.92 µM), (IIIc) (IC50 = 19.11 ± 0.55 µM), and (IIIf) (IC50 = 21.01 ± 1.42 µM) were found as promising lead urease inhibitors, stronger than the standard thiourea (IC50 = 21.15 ± 0.32 µM). Moreover, compound (IIIa) (IC50 = 40.21 ± 0.12 µM) was found as the excellent antioxidant agent comparing it with the standard ascorbic acid. Molecular docking study was performed to analyze the most potent compounds against urease enzyme. The results also shows that all compounds had good ADME properties there was no violation found in compounds ranges all are under druglikness criteria. Additional research combining in vivo, toxicological, and computational analyses can offer thorough understandings of the effectiveness, safety, and fundamental mechanisms of action of these potentially beneficial antioxidant substances. Conclusions: These compounds showed tremendous potential as DPPH free radical scavengers and urease enzyme inhibitors. Compound (IIId) demonstrated the greatest suppression of urease enzyme activity, however compound (IIIa) displayed superior antioxidant effects. Additional research, incorporating in vivo, toxicological, and computational examinations, is necessary to thoroughly assess the effectiveness, safety, and fundamental mechanisms of action of these intriguing antioxidant molecules. [ABSTRACT FROM AUTHOR]

BACKROUND: Aonla is as a good source of antioxidants due to its high ascorbic acid and polyphenol contents. However, because of its high acidity and astringent taste, aonla is rarely consumed in its fresh form. As the constituents in aonla are heat sensitive, it is essential to find a suitable drying method for preservation. Therefore, refractance window drying (RWD) of aonla slices was studied as it has the potential of retaining heat‐sensitive compounds. Results: The effect of RWD process variables, namely water temperature (75, 82.5, 90 °C) and slice thickness (2, 4, 6 mm), on different quality parameters of dehydrated aonla was studied. Increasing water temperature resulted in significantly higher ascorbic acid content, titratable acidity and product temperature, while total phenolic content, free radical scavenging activity and moisture content decreased. With the exception of product temperature, higher slice thickness led to an increase in the values of all the parameters. At the optimized processing conditions of 83 °C water temperature and 4 mm slice thickness, the ascorbic acid content, total phenolic content, free radical scavenging activity, titratable acidity and moisture content values were found to be 269.03 mg (100 g)−1, 242.33 mg (100 g)−1, 87.11%, 3.62% and 4% respectively. The aonla slices subjected to RWD also possessed 4–6% higher phytochemical content than osmotically dried and hot‐air‐dried samples. Conclusion: This research highlights the effectiveness of RWD in preserving heat‐sensitive compounds in food like aonla. The RW‐dried slices had a smoother and more uniform microstructure compared to osmotically dried and hot‐air‐dried samples. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The role of the sulfur analog of cyclic ketene acetals in the synthesis of polyvinyl chloride is examined in this study. In this context, whether 2‐methylene‐1,3‐dithiolane (S‐CKA5), 2‐methylene‐1,3‐dithione (S‐CKA6), and 2‐methylene‐1,3‐dithiepane (S‐CKA7) monomers are involved in the radical polymerization of vinyl chloride through the ring opening reaction is examined by quantum chemical methods. In light of calculations at the M06‐2X/6‐31+G(d) level, it is concluded that, in general, S‐CKAs undergo little or no ring‐opening and form block copolymers, mainly with the homopolymerization of S‐CKAs and their ring‐retaining step. It is determined that S‐CKA7 is the most prone to ring‐opening reaction and inserting dithioate links to the polymer backbone. However, the radical ring‐opening of S‐CKA7 is strongly reversible, as in other S‐CKAs. [ABSTRACT FROM AUTHOR]

In this study five different complexes of Cu(II) were synthesized for the purpose of environmentally notorious mercury sensing and preliminary biological screening. Pyridine‐2,6‐dicarboxylic acid (also known as dipicolinic acid, and abbreviated as H2DPA), 3‐phenyl pyrazole (3‐ppz), 4‐iodo‐1H‐pyrazole (4‐ipz), 4‐nitropyrazole (4‐npz), 4‐bromopyrazole (4‐bpz), and 4‐chloropyrazole (4‐cpz) were chosen as potential ligands. The synthesized complexes labelled as 1–5, namely [Cu(DPA)(3‐ppz)], [Cu(DPA)(4‐ipz)], [Cu(DPA)(4‐npz)], [Cu(DPA)(4‐bpz)], [Cu(DPA)(4‐cpz)], were proposed based on spectroscopic data (FTIR, TGA, and UV‐visible spectroscopy). These complexes feature C=O functionalities that are not involved in coordination and may be used for further applications. The isolated complexes were utilized for detecting Hg(II) ions in water samples. Various concentrations of Hg(II) ions were prepared for detection purposes, and changes in absorption concerning complexes 1–5 were determined using UV‐Visible spectroscopy. It was found that complexes 3 and 4 exhibit efficient sensing abilities towards Hg(II) ions. The antibacterial activities of complexes 1–5 were assessed against S. typhi and E. coli. The complexes 1 and 3 displayed good antibacterial activities against S. typhi (13.67, and 13.56 mm, respectively) while complexes 1, 2 and 4 were found to be efficient against E. coli (11.6, 12.66, 11.31 mm, respectively). The absorption maxima of 2,2‐diphenyl‐1‐picryhydrazyl (DPPH) at 517 nm, considerably shifted upon addition of complexes 1–5. The results reveal that the complexes possess potential free radical scavenging abilities. [ABSTRACT FROM AUTHOR]

Mechanistic understanding of free radical polymerization (FRP) in aqueous solution is hindered by the lack of kinetic coefficient data. Here, we investigated the propagation rate coefficient (kp) for FRP of HEMA in aqueous solution. The kp at 80 °C increased by 6 times as the monomer weight fraction in aqueous system decreases from 100 wt.% to 6 wt.%, that is., from 6.0 × 103 to 3.3 × 104 L·moL−1·s−1. This increase in kp is associated with the increase in pre‐exponential factor (A), which suggests an increase in entropy with increasing water molecules in the polymerization system. To investigate the effect of solvent on kp, pulse‐laser polymerization in solvents of different hydrogen bonding affinity, that is, 50 wt.% butyl propionate (BP) and dimethyl formamide (DMF), are conducted. The kp obtained are in order of kp,bulk∼kp,BP > kp,DMF, suggesting that the intermolecular hydrogen bonding at carbonyl moieties critically affects the geometry of transition state quasi‐equilibrium in propagation. We underpinned this observation by analyzing the carbonyl and alkene moieties of HEMA in different solvents using infrared (IR) spectroscopy. The mechanistic analyses and insights relating to hydrogen bonding and functional moieties can be relevant for future studies involving non‐aqueous solvents promoting hydrogen bonds. [ABSTRACT FROM AUTHOR]

Background: Migraine-related perfusion changes are documented but inconsistent across studies due to limited sample size and insufficient phenotyping. The phasic and spatial dynamics across migraine subtypes remains poorly characterized. This study aimed to determine spatiotemporal dynamics of gray matter (GM) perfusion in migraine. Methods: We prospectively recruited episodic (EM) and chronic migraine (CM) patients, diagnosed with the International Headache Society criteria and healthy controls (HCs) between 2021 and 2023 from the headache center in a tertiary medical center, and adjacent communities. Magnetic resonance (3-tesla) arterial spin labeling (ASL) was conducted for whole brain cerebral blood flow (CBF) in all participants. The voxel-wise and whole brain gray matter (GM) CBF were compared between subgroups. Spatial pattern analysis of CBF and its correlations with headache frequency were investigated regarding different migraine phases and subtypes. Sex- and age-adjusted voxel-wise and whole brain GM comparisons were performed between HCs and different EM and CM phases. Spatial pattern analysis was conducted by CBF clusters with phasic differences and spin permutation test. Correlations between headache frequency and CBF were investigated regarding different EM and CM phases. Results: Totally 344 subjects (172 EM, 120 CM, and 52 HCs) were enrolled. Higher CBF in different anatomical locations was identified in ictal EM and CM. The combined panels of the specific locations with altered CBF in ictal EM on receiver operating characteristic curve analysis demonstrated areas under curve of 0.780 (vs. HCs) and 0.811 (vs. preictal EM). The spatial distribution of ictal-interictal CBF alteration of EM and CM were not correlated with each other (p = 0.665; r = − 0.018). Positive correlations between headache frequency and CBF were noted in ictal EM and CM regarding whole GM and specific anatomical locations. Conclusions: Patients with migraine exhibited unique spatiotemporal CBF dynamics across different phases and distinct between subtypes. The findings provide neurobiological insights into how selected anatomical structures engage in a migraine attack and adapt to plastic change of repeated attacks along with chronicity. [ABSTRACT FROM AUTHOR]

The research aimed to evaluate the antioxidative and antibacterial characteristics of aqueous sumac extract on methicillin-resistant Staphylococcus aureus through in-vitro and in-vivo study. Sumac extract has been obtained through the soaking method, and its antioxidant properties were gauged using the DPPH free radical scavenging method. The minimum inhibitory concentration (MIC) of sumac extract was determined on S. aureus obtained from hospitalized patients, as well as an assessment of biofilm-formation and the release of bacterial intracellular compounds. in vivo experimentation involved injecting bacteria (108 cfu/ml) into mice, which subsequently manifested indicators of symptoms of infection, and the number of bacteria within their bloodstream was quantified. The Sumac extract demonstrated strong antioxidant properties at concentrations of 1000 mg/ml. Furthermore, the agar tests for the gram staining, mannitol, coagulase, and DNase revealed that 190 cultured bacteria samples were identified as Staphylococcus aureus. These bacteria were resistant to clindamycin, ciprofloxacin, and methicillin antibiotics, but sensitive to erythromycin and penicillin antibiotics. Additionally, the bacteria displayed significant methicillin resistance and formed a strong biofilm (65.78%). The sumac extract showed a MIC range of 125–1000 µg/ml against Staphylococcus aureus. Treatment with concentrations above the MIC was found to prevent the formation of biofilm and increase the release of bacterial intracellular compounds. Sumac extract led to a decrease in bacterial count in the blood of mice and reduced signs of infection. Sumac extract demonstrated powerful antioxidant and antibacterial effects against resistant microorganisms, suggesting its potential as a promising compound for the treatment of resistant infections in future research. [ABSTRACT FROM AUTHOR]

The basis of most neurological syndromes is the accumulation of free radical molecules. Quercetin is a polyphenolic bioflavonoid molecule and it has a very strong antioxidant effect by maintaining oxidative balance. There are many difficulties in the clinical use of quercetin due to its hydrophobic structure, low solubility, instability, poor oral bioavailability, and limited tissue-barrier penetration. Its synergistic use in complex with gold nanoparticles (AuNPs) could overcome these problems. AuNPs have recently emerged as an attractive candidate for delivery applications of various biomolecules and drugs. The aim of this study was to synthesize two different sized gold nanoparticles (AuNP 20 and AuNP 50) modified with polyethyleneimine (PEI) and quercetin, evaluate their potential neuroprotective effects on the in vitro oxidative stress model using DRG primary sensory neurons. It was shown that the antioxidant and anti-apoptotic ability of the bioflavonoid was preserved after exposure to the designed quercetin modified AuNPs. The PEI surface coating increased the stability and biocompatibility of the AuNPs in both sizes. It also potentially enables additional surface functionalization. This study indicates that designed nanoparticles (AuNP-Q-PEI) with different sizes could be a useful potential platform for the treatment of neurodegenerative syndromes or cancer diseases. Quercetin/PEI modified and two different sized (AuNP 20 and AuNP 50) gold nanoparticles were successfully synthesized. Designed nanoplatform (AuNPs-Q-PEI) increased stability and biocompatibility. After nanomaterial exposure in the oxidative stress model of the DRG sensory neurons, the level of ROS and apoptosis was significantly reduced. [Display omitted] • Quercetin/PEI modified and two different sized (AuNP 20 and AuNP 50) gold nanoparticles were successfully synthesized. • The antioxidant property of the bioflavonoid was preserved after exposure to designed Q-coated AuNPs in the DRG neurons. • The PEI surface coating increased the stability and biocompatibility of the AuNPs in both sizes. • The designed gold nanoconjugates could be a useful potential nanoplatform for the treatment of neurodegenerative syndromes. [ABSTRACT FROM AUTHOR]

Photodynamic therapy (PDT) represents a promising strategy for tumor treatment. However, the development of PDT‐based antitumor therapies faces challenges stemming from the hypoxic nature of the tumor microenvironment and the limited penetration of photosensitizers. This study presents a novel class of antitumor nanoparticles, designated as ARLN‐FP, engineered to penetrate tumor tissues deeply and inhibit tumor growth through the generation of oxygen‐independent free radicals. With the encapsulation of IR780 and dimethyl 2,2′‐azobis(2‐methylpropionate) (AIBME) in the core of ARLN‐FP, near‐infrared (NIR) laser irradiation of ARLN‐FP with induced heat generation, which subsequentially led to the decomposition of AIBME and the production of free radicals without relying on oxygen. In vitro studies indicated that ARLN‐FP penetrated more than 100 µm into multicellular tumor spheroids, demonstrating its enhanced tissue permeability. Animal studies confirmed the anti‐tumor effects of ARLN‐FP‐mediated photonic thermodynamic therapy, where the oxygen‐independent radical formation contributed to successful tumor eradication, evidenced by a significant tumor inhibition rate of 90.8% after 22 days. This research presents a feasible method to overcome the limitations of traditional oxygen‐dependent photodynamic therapies, which offers a new approach to developing nanomedicines to overcome resistance in deep and hypoxic tumor regions. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effects of copper (CuSO4) and zinc (ZnSO4) overload on male reproductive toxicity and the potential of a polysaccharide extracted from green alga Chaetomorpha linum (PS) in mitigating their toxicities. Adult male mice strain of 25 ± 2 g of weight was subdivided into eight groups. Group 1 served as control; group 2 received PS (200 mg/kg), and groups 3 and 4 received intraperitoneally zinc (60 mg/kg b.w) and copper (33 mg/kg b.w), respectively. Group 5 received both zinc (60 mg/kg b.w) and copper (33 mg/kg b.w), group 6 received zinc (60 mg/kg b.w) associated with PS (200 mg/kg), group 7 received copper (33 mg/kg b.w) associated with PS (200 mg/kg), and group 8 received zinc (60 mg/kg b.w) and copper (33 mg/kg b.w) associated with PS (200 mg/kg). Results suggested that ZnSO4 and CuSO4 significantly decreased the functional sperm parameters. Furthermore, extended exposure to these elements increased oxidative stress biomarkers, including malondialdehyde (MDA) as a measure of lipid peroxidation and advanced oxidation protein products (AOPP) indicating protein oxidative damage. This process also reduces the activity of antioxidant enzymes such as glutathione (GSH) and glutathione peroxidase (GPx), which neutralize and catalyze free radicals. Histopathological changes in mice testis were also studied. However, the co-treatments with PS significantly reduced these effects and promoted the reproductive parameters in male mice. In conclusion, PS exhibited protective effects against zinc and copper-induced reproductive toxicity, making it a potential adjuvant treatment for testicular toxicity. [ABSTRACT FROM AUTHOR]

Vat photopolymerization (VPP) based additive manufacturing (AM) technologies print 3D components by using light to selectively cure photosensitive resins. In VPP-based AM, one outstanding challenge remains in controlling the over-curing, which is mainly caused by the diffusive and/or excessive photo-induced species such as free radicals and can severely affect the geometric properties of as-printed parts. Common practices rely on formulating proper resins or optimizing exposure parameters to address the vertical over-curing but often ignore the lateral over-curing. In this work, we develop a new VPP process of photoinhibition aided photopolymer AM (PinPAM) to comprehensively address over-curing issues in both vertical and lateral dimensions for enhancing the properties of as-printed geometry. The PinPAM method incorporates an adaptive photoinhibition zone, generated both surrounding and underneath the curing zone on a layer basis. This differs from current literature approaches that utilize photoinhibition to create a higher deadzone to increase print speed or constrain vertical profiles for achieving volumetric VPP AM. We present several preliminary experimental study cases involving pillar array sample printing. By comparing part dimensions and shapes resulting from traditional VPP and PinPAM, our experiments prove the concept of PinPAM and demonstrate its potential to address over-curing in VPP. Furthermore, we present an initial case study on optimizing the PinPAM process for printing cylinder samples with targeted dimensions, illustrating the planning and implementation of PinPAM. A discussion on future research directions to establish PinPAM is included. The developed PinPAM opens up a new avenue for improving VPP printed parts' geometrical properties and facilitating its adoption in precision fabrications that demand dimensional accuracy and resolution. • New photoinhibition aided photopolymer additive manufacturing (PinPAM) process. • Novel use of photoinhibition to enhance lateral accuracy and resolution. • Feature Proof-of-concept: PinPAM addresses 3-dimensional over-curing in pillar array print. • Effects of inhibition patterning, e.g., surrounding, overlapping, intensity, shape. • Optimizing inhibition exposure in PinPAM to advance photopolymer 3D printing. [ABSTRACT FROM AUTHOR]