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The photocatalyst S-scheme BiFeO3–g-C3N4 had been prepared by combining calcination and hydrothermal reaction. 10% BiFeO3–g-C3N4 composite showed the greatest photocatalytic effect during tetracycline hydrochloride degradation (TC-HCl, 99.7% removal) within 100 min. Meantime, the photocatalytic efficacy was further confirmed by the removal efficiency of ciprofloxacin(CIP, 98.2% removal). The formation of S-scheme heterostructure and matching valence band and conduction band may be responsible for the improved photocatalytic efficiency of BiFeO3–g-C3N4. This leads to the rapid separation of photo-induced carriers, increased electronic transport capacity, and extended carrier lifetime. A study was done on the potential mechanism by employing chemical scavenger experiment revealing the paramount role of O2−. The composite could maintain photocatalytically stable even after five consecutive reaction cycles. The recovery efficiency of 10% BiFeO3–g-C3N4 was high because of the magnetic property of BiFeO3, which was convenient for the recycling process. The produced photocatalyst has potential use in the field of photocatalysis, and this work provides a novel thought to raise the photocatalysts recovery efficiency during recycling. [ABSTRACT FROM AUTHOR]

Red blood cells (RBCs) become sickle‐shaped and stiff under hypoxia as a consequence of hemoglobin (Hb) polymerization in sickle cell anemia. Distinguishing between sickle cell disease and trait is crucial during the diagnosis of sickle cell disease. While genetic analysis or high‐performance liquid chromatography (HPLC) can accurately differentiate between these two genotypes, these tests are unsuitable for field use. Here, we report a novel microscopy‐based diagnostic test called ShapeDx™ to distinguish between disease and trait blood in less than 1 h. This is achieved by mixing an unknown blood sample with low and high concentrations of a chemical oxygen scavenger and thereby subjecting the blood to slow and fast hypoxia, respectively. The different rates of Hb polymerization resulting from slow and fast hypoxia lead to two distinct RBC shape distributions in the same blood sample, which allows us to identify it as healthy, trait, or disease. The controlled hypoxic environment necessary for differential Hb polymerization is generated using an imaging microchamber, which also reduces the sickling time of trait blood from several hours to just 30 min. In a single‐blinded proof‐of‐concept study conducted on a small cohort of clinical samples, the results of the ShapeDx™ test were 100% concordant with HPLC results. Additionally, our field studies have demonstrated that ShapeDx™ is the first reported microscopy test capable of distinguishing between sickle cell disease and trait samples in resource‐limited settings with the same accuracy as a gold standard test. [ABSTRACT FROM AUTHOR]

Melatonin is a small natural compound, so called a neuro‐hormone that is synthesized mainly in pineal gland in animals. Its main role is to master the clock of the body, under the surveillance of light. In other words, it transfers the information concerning night and day to the peripheral organs which, without it, could not "know" which part of the circadian rhythm the body is in. Besides its main circadian and circannual rhythms mastering, melatonin is reported to be a radical scavenger and/or an antioxidant. Because radical scavengers are chemical species able to neutralize highly reactive and toxic species such as reactive oxygen species, one would like to transfer this property to living system, despite impossibilities already largely reported in the literature. In the present commentary, we refresh the memory of the readers with this notion of radical scavenger, and review the possible evidence that melatonin could be an in vivo radical scavenger, while we only marginally discuss here the fact that melatonin is a molecular antioxidant, a feature that merits a review on its own. We conclude four things: (i) the evidence that melatonin is a scavenger in acellular systems is overwhelming and could not be doubted; (ii) the transposition of this property in living (animal) systems is (a) theoretically impossible and (b) not proven in any system reported in the literature where most of the time, the delay of the action of melatonin is over several hours, thus signing a probable induction of cellular enzymatic antioxidant defenses; (iii) this last fact needs a confirmation through the discovery of a nuclear factor—a key relay in induction processes—that binds melatonin and is activated by it and (iv) we also gather the very important description of the radical scavenging capacity of melatonin in acellular systems that is now proven and shared by many other double bond‐bearing molecules. We finally discussed briefly on the reason—scientific or else—that led this description, and the consequences of this claim, in research, in physiology, in pathology, but most disturbingly in therapeutics where a vast amount of money, hope, and patient bien‐être are at stake. [ABSTRACT FROM AUTHOR]

Antioxidants are various types of compounds that represent a link between biology and chemistry. With the development of theoretical and computational methods, antioxidants are now being studied theoretically. Here, a novel method is presented that aims to reduce the estimated wall times for DFT calculations that result in the same or higher degree of accuracy in the second derivatives over energy than is the case with the regular computational route (i.e., optimizing the reaction system at a lower model and then recalculating the energies at a higher level of theory) by applying the inversion of theory level to the universal chemical scavenger model, i.e., phenol. The resulting accuracy and wall time obtained with such a methodological setup strongly suggest that this methodology could be generally applied to antioxidant thermodynamics for some costly DFT methods with relative absolute deviation. [ABSTRACT FROM AUTHOR]

Photoreforming is a process that connects the redox capability of photocatalysts upon light illumination to simultaneously drive the reduction of protons into hydrogen and the oxidation of organic substrates. Over the past few decades, researchers have devoted substantial efforts to enhancing the photocatalytic activity of the catalyst in hydrogen production. Currently, the realization of the potential of photocatalysts for simultaneous hydrogen production with value-added organics has motivated the research field to use the photo-oxidation path. As a distinct benefit, the less energetically demanding organic reforming is highly favorable compared to the slow kinetics of oxygen evolution, negating the need for expensive and/or harmful hole scavengers. Photocatalyst modifications, such as secondary component deposition, doping, defect, phase and morphology engineering, have been the main strategies adopted to tune the photo-oxidation pathways and oxidation products. The effect of the reaction parameters, including temperature, pH, reactant concentration and promising reactor strategies, can further enhance selectivity toward desired outcomes. This review provides a critical overview of photocatalysts in hydrogen production, including chemical reactions occurring with semiconductors and co-catalysts. The use of various oxygenates as sacrificial agents for hydrogen production is outlined in view of the transition of fossil fuels to clean energy. This review mainly focuses on recent development in the photoreforming of carboxylic acids, produced from the primary source, lignocellulose, through pyrolysis. The photo-oxidation of different carboxylic acids, e.g., formic acid, acetic acid and lactic acid, over different photocatalysts for hydrogen production is reviewed. [ABSTRACT FROM AUTHOR]

The activation of persulfate (PS) under UVA irradiation by two TiO 2 polymorphs (brookite and anatase) and titanate photocatalysts was evaluated for the simultaneous removal of the biocides methylisothiazolinone (MIT) and chloromethylisothiazolinone (CMIT), in ultrapure water and real sewage treatment plant water (SW). Titania and titanate samples were synthesized by a hydrothermal method and characterized by XRD, SEM, N 2 adsorption-desorption isotherms and UV-Vis DR. The reactions were performed in individual (brookite, anatase, titanate and PS) and hybrid (titania/PS and titanate/PS) systems and compared to those with TiO 2 -P25 as reference. In ultrapure water, the combined brookite/PS system showed a higher performance for MIT and CMIT abatement and a stronger synergistic effect between titania and PS than found in anatase/PS and titanate/PS systems, indicating the higher effectiveness of the brookite phase for PS activation under UVA. The use of SW water revealed the strong inhibitory effect of matrix constituents in the individual brookite, anatase and PS systems, which exhibited a low performance. However, the kinetics of MIT/CMIT in SW were greatly enhanced in the hybrid TiO 2 /PS systems, especially with brookite, leading to an efficient degradation of both pollutants and the decrease of total organic carbon (TOC). The addition of chemical scavengers showed a similar reactivity of HO• towards both isothiazolinones whereas a preferential attack of SO 4 • − to MIT was observed, demonstrating the selective nature of SO 4 • −. [Display omitted] [ABSTRACT FROM AUTHOR]

Main conclusion: Upregulated expression of RESPIRATORYBURSTOXIDASEHOMOLOGD (RBOHD) encoding a plasma membrane NADPH oxidase is responsible for the lesion-mimic phenotype in detached Arabidopsis leaves with mutation of PHEIDEaOXYGENASE during extended darkness. Chlorophyll degradation is an indispensable process in leaf senescence, either age-dependent or dark-induced. Besides higher chlorophyll retention, a lesion-mimic phenotype (abbreviated as LMP afterwards) was exhibited in Arabidopsis leaves with mutation of PHEIDE a OXYGENASE (PaO) involved in chlorophyll degradation during dark incubation, but the associated mechanism remains elusive. We found that dark-treated pao leaves showed higher membrane damage and H2O2 accumulation, while scavenging H2O2 by its chemical scavenger diminished LMP. RBOHD which encodes NADPH oxidase was strikingly up-regulated in pao leaves during dark treatment. Chemical inhibition of NADPH oxidase or mutation of RBOHD in pao leaves suppressed LMP. Thus, our study suggests that up-regulated RBOHD transcription is responsible for the formation of LMP in dark-treated pao leaves and there may be a retrograde signaling pathway mediating upregulation of RBOHD which remains to be elucidated. [ABSTRACT FROM AUTHOR]

Pharmaceutical CEC compounds are a potential threat to man, animals, and the environment. In this study, a sol–gel-derived TiO2 (SynTiO2) was produced and subsequently sonochemically doped with a 1.5 wt% Mo to obtain the final product (Mo (1.5 wt%)/SynTiO2). The as-prepared materials were characterized for phase structure, surface, and optical properties by XRD, TEM, N2 adsorption–desorption BET isotherm at 77 K, and PSD by BJH applications, FTIR, XPS, and UV-Vis measurements in DRS mode. Estimated average crystallite size, particle size, surface area, pore-volume, pore size, and energy bandgap were 16.10 nm, 24.55 nm, 43.30 m2/g, 0.07 cm3/g, 6.23 nm, and 3.05 eV, respectively, for Mo/SynTiO2. The same structural parameters were also estimated for the unmodified SynTiO2 with respective values of 14.24 nm, 16.02 nm, 133.87 m2/g, 0.08 cm3/g, 2.32 nm, and 3.3 eV. Structurally improved (Mo (1.5 wt%)/SynTiO2) achieved ≈100% carbamazepine (CBZ) degradation after 240 min UV irradiation under natural (unmodified) pH conditions. Effects of initial pH, catalyst dosage, initial pollutant concentration, chemical scavengers, contaminant ions, hydrogen peroxide (H2O2), and humic acid (HA) were also investigated and discussed. The chemical scavenger test was used to propose involved photocatalytic degradation process mechanism of CBZ. [ABSTRACT FROM AUTHOR]

Worldwide energy and environmental issues are forcing researchers to develop a green approach to produce a clean energy. However, traditional methods in reforming of fossil fuels to produce hydrogen (H2) are causing CO2 emission. Hydrogen is therefore an indirect greenhouse gas with a global warming potential. Hydrogen with high specific energy density can be considered as an efficient energy carrier as compared to fossil fuels. But hydrogen production from water splitting reaction has low efficiency, which limits its generation by green approach. For addressing this issue, different chemical hole scavengers have been applied, which is causing further environmental and economic problems. By using biomass as a hole scavenger to improve rate of H2 generation, environmental pollution can be controlled and value-added chemicals can be produced via its oxidation reaction. In this mini review, the effect of different influencing factors such as type of biomass feedstock, irradiation wavelength and intensity, and nature and function of applied photocatalysts in particular their structural/dimensional on the biomass photocatalytic reforming process to produce clean hydrogen will be discussed. Moreover, the fundamental principles of this process including kinetics and mechanism of the reaction will be also addressed. [ABSTRACT FROM AUTHOR]

Surface air discharge has been extensively reported to have strong antibacterial and anticancer effects, and these biological effects are more or less attributed to the short-lived aqueous reactive species produced by the air plasma. Insight into the generation mechanism for short-lived species is a key bottleneck in elucidating the antimicrobial and anticancer effects. Although the numerical study has predicted that the dissolution of gaseous NO3 plays a crucial role, but so far without experimental validation. In view of this, cavity ring-down spectroscopy is adopted in this paper to measure the NO3 spatial distribution between the surface air discharge and the solutions to be treated, and the concentrations of short-lived species in the solutions after plasma treatment are also measured for different discharge modes. A simplified chemical pathway for the conversion of gaseous NO3 to aqueous ONOOaq−/ONOOHaq and O2aq− is proposed. Moreover, the inactivation effects for Escherichia coli and A549 lung cancer cells treated by the plasma-activated solutions are measured for different concentrations of short-lived species, and the key species for sterilization and anticancer are identified by chemical scavengers. Finally, a positive correlation chain is found among the inactivation effect, the concentrations of aqueous ONOOaq−/ONOOHaq and O2aq−, and the density of gaseous NO3, implying that NO3 might be very important for the production of aqueous short-lived reactive species as well as the biological effects induced by plasma-activated solutions. [ABSTRACT FROM AUTHOR]

Sulfide species (inorganic and organic sulfides) are well known for their toxicity and corrosiveness. Several industries, including oil and gas, are prone to corrosive damage due to sulfides that necessitate their timely removal using appropriate methods. Employing chemical scavengers is the most suitable method where the scavenger combine with dissolved sulfides in aqueous/hydrocarbon phase and convert them to a nontoxic and less corrosive form that can be easily removed from the stream. Instead of direct chemical scavenger addition, different approaches, including absorption and adsorption methods, are employed in eliminating sulfide species from gas streams in different industrial applications. This review provides a detailed account of various sulfide scavengers used in oil and gas sweetening. Most recent research advancements in this area are highlighted. A brief account of the latest reported works on novel adsorbents for the desulfurization process for refinery fuels is also provided. The review ends with a short discussion on catalytic hydrodesulfurization. [ABSTRACT FROM AUTHOR]

Significant advancements have been made towards exploitation of naturally available molecular motors and their associated cytoskeletal filaments in nanotechnological applications. For instance, myosin motors and actin filaments from muscle have been used with the aims to establish new approaches in biosensing and network-based biocomputation. The basis for these developments is a version of the in vitro motility assay (IVMA) where surface-adsorbed myosin motors propel the actin filaments along suitably derivatized nano-scale channels on nanostructured chips. These chips are generally assembled into custom-made microfluidic flow cells. For effective applications, particularly in biocomputation, it is important to appreciably prolong function of the biological system. Here, we systematically investigated potentially critical factors necessary to achieve this, such as biocompatibility of different components of the flow cell, the degree of air exposure, assay solution composition and nanofabrication methods. After optimizing these factors we prolonged the function of actin and myosin in nanodevices for biocomputation from <20 min to >60 min. In addition, we demonstrated that further optimizations could increase motility run times to >20 h. Of great importance for the latter development was a switch of glucose oxidase in the chemical oxygen scavenger system (glucose oxidase–glucose–catalase) to pyranose oxidase, combined with the use of blocking actin (non-fluorescent filaments that block dead motors). To allow effective testing of these approaches we adapted commercially available microfluidic channel slides, for the first time demonstrating their usefulness in the IVMA. As part of our study, we also demonstrate that myosin motor fragments can be stored at −80 °C for more than 10 years before use for nanotechnological purposes. This extended shelf-life is important for the sustainability of network-based biocomputation. [ABSTRACT FROM AUTHOR]

In plasma-driven biocatalysis, enzymes are employed to carry out reactions using species generated by non-thermal plasmas as the precursors. We have previously demonstrated that this is feasible in principle, but that the approach suffers from the short lifetime of the biocatalyst under operating conditions. In this work, protection strategies were investigated to prevent the dielectric barrier discharge plasma-induced inactivation of biocatalysts, using recombinant unspecific peroxygenase from Agrocybe aegerita(rAaeUPO), one of the most promising enzymes for plasma-driven biocatalysis. Treatment in oxygen-free atmospheres did not provide any advantage over treatment in synthetic air, indicating that the detrimental reactive species did not originate from oxygen in the plasma phase. Chemical scavengers were employed to eliminate undesired reactive species, without any long-term effect on enzyme lifetime. Similarly, chaperones, including the known stress response proteins Hsp33, CnoX, and RidA did not increase the lifetime of rAaeUPO. Immobilization of the biocatalyst proved effective in preserving enzyme activity. The residual activity of rAaeUPO after plasma treatment strongly depended on the specific immobilization support. Essentially complete protection for at least 15 min of plasma exposure was achieved with an epoxy-butyl-functionalized carrier. This study presents new insights into plasma–protein interactions and plots a path forward for protecting biocatalytic proteins from plasma-mediated inactivation. [ABSTRACT FROM AUTHOR]

A convenient and efficient method to fabricate isolated Fe single-atom catalysts deposited on Myriophyllum aquaticum -based biochar (ISA-Fe/MC) is reported for peroxymonosulfate-based organics degradation. Firstly, the Fe nanoparticles anchored on the hierarchical porous biochar (nano-Fe/MC) can be obtained by utilizing K 2 FeO 4 as a synchronous activation and graphitization agent. Subsequently, ISA-Fe/MC was achieved by HCl etching of nano-Fe/MC to remove the excess Fe nanoparticles. Compared with nano-Fe/MC, ISA-Fe/MC demonstrated outperformed catalytic capacity towards PMS activation for phenol degradation. The combination of super high surface area, hierarchical porous structure, graphitization structure and atomically dispersed Fe species should be responsible for prominent catalytic oxidation ability and outstanding resistance to common anions and humic acid. Based on the chemical scavengers, EPR experiments and electrochemistry tests, the SO 4 •– dominated radical degradation pathway for nano-Fe/MC and electron transfer reigned non-radical degradation pathway for ISA-Fe/MC was revealed. In contrast to nano-Fe/MC, density functional theory calculations demonstrated the enhanced density of states around Fermi level in ISA-Fe/MC meaning the increased catalytic performance and more electron transfer between single-atom Fe to adjacent graphitic C and N which could serve as electron transfer channel for PMS activation. [ABSTRACT FROM AUTHOR]

The textile industry is responsible for most of the consumption and inappropriate disposal of organic and highly toxic pollutants, such as dyes. Therefore, it is necessary to remediate polluting molecules before returning the water to the environment. Photocatalysis is a promising method for dye molecule degradation as it can provide complete mineralization through an efficient photocatalytic process. CuWO4 exhibits a band gap of 2.40 eV and can be excited with visible light, making it economically advantageous for industrial-scale applications. In this work, CuWO4 was synthesized by coprecipitation (CM), microwave-assisted hydrothermal (HM), and polymeric precursor (PPM) methods to evaluate the photocatalytic behavior in response to the different characteristics obtained from the synthesis routes. In photocatalytic measurements for OH· radical generation, the sacrificial agent H2O2 was used, and in order to delay the recombination process sodium oxalate and silver nitrate scavengers were applied under visible light. CuWO4 synthesized by PPM was more efficient in the dye degradation when the Ag+ scavenger was used, indicating that the predominant reaction mechanism was by direct oxidation or hydroxyl radicals. The surface charge (− 38.5 (PPM), − 29.7 (CM), and − 16.2 mV (HM)) influence was more relevant than the specific surface area (1 (PPM), 22 (CM), and 21 m2 g−1 (HM)) of the samples in the photocatalytic process. The complete degradation occurred in 80 min for the samples obtained by CM and HM and only 20 min were necessary for the sample synthesized by PPM. [ABSTRACT FROM AUTHOR]

In order to identify the productive and perspective perforation in the deposits with scavenger reserves, one often faces a number of problems that prevent the selection of the most perspective intervals. One can add to these intervals the misinterpretation of geophysical well logging, as a result of drill mud colmatation into the formation or technogenic disturbances in the core of rocks that occur during lifting, sample preparation and analysis by classical petrophysical methods. In this regard, the authors of this article present a method of computer x-ray microtomography in order to develop criteria for the prospects of intervals in deposits with scavenger reserves. The article underlines the prospects of the computer xray microtomography method: 3D modelling, calculation of porosity and clay coefficients, volume fraction of heavy minerals, estimation of pore distribution by size and depth of drilling mud penetration of the core, as well as experimental output with recommendations for the usage of method during experiments before and after any impact. In accordance with the research results, we concluded that the method of computer x-ray microtomography under the study of core material can help in the development of effective criteria in order to identify the promising intervals for perforation in the section of a well with deposits with scavenger reserves of hydrocarbon. One can do this if there is a sufficient test and information sampling in relation to the test results under study. [ABSTRACT FROM AUTHOR]

• The use of EDTA during the synthesis of BiOBr enhances its photocatalytic activity. • The EDTA was an efficient structure-directing agent of the BiOBr formation reaction. • BiOBr was highly selective to NO 3 – ions formation in the NO oxidation reaction. • BiOBr can be the basis to develop photocatalytic coatings with DeNO x ability. Bismuth oxybromide (BiOBr) was synthesized in aqueous medium in presence of EDTA as structure-directing agent following a simple coprecipitation method at 23 °C and by microwave irradiation at 110 °C. The physicochemical properties of BiOBr (morphology, specific surface area, energy band gap and photocatalytic activity) were modified using different EDTA concentrations. Nanoparticles of BiOBr with {1 1 0} crystallographic exposed facets were obtained as a peculiar feature of the synthesis followed. The photocatalytic activity of BiOBr was evaluated in the oxidation reaction of nitric oxide (NO) in gaseous phase under UV–Vis and visible irradiation. An enhancement in the NO conversion degree was reached for BiOBr synthesized by coprecipitation with an EDTA/Bi molar ratio of 0.6. This sample showed a NO conversion degree of 94%, a selectivity to nitrate ions of 98%, a good stability after four cycles of irradiation and sample was able to retain its high photocatalytic activity under humidity conditions (70% RH). The use of different chemical scavengers revealed that superoxide radical (O 2 •-) was the main reactive specie in the mechanism of the photocatalytic reaction. BiOBr photocatalyst was successfully incorporated in two formulations of ceramic coatings to develop prototypes of building materials with active surface for the photocatalytic elimination of NO x gases from the air. [ABSTRACT FROM AUTHOR]

The present study intends to evaluate the chemical composition, antioxidant activity and GC-MS analysis of marine red seaweed Ahnfeltia plicata. The Alga was collected, shade dried, ground into a fine powder and extracted with eight different solvents to examine their extractive value and phytochemical constituents. The chemical components present in Ahnfeltia plicata were analyzed, and its free radical scavenging activity was determined by the DPPH assay. The seaweed was subjected to GC-MS analysis which revealed the presence of 20 different compounds. From the present research, it is concluded that Ahnfeltia plicata is a rich source of bioactive molecules. [ABSTRACT FROM AUTHOR]

We investigated the influence of multiple extrusions of poly-(ethylene terephthalate) (PET) blended with a polymer-based oxygen scavenger. PET and PET blended with an oxygen scavenger additive were extruded up to four times to polymer strands. They were chilled in a water bath and cut to granules. Between the extrusions, the granules were dried at (only) 60°C to avoid the oxygen scavenger losing its reactivity. The water content was up to 0.5 wt.-% and therefore up to factor 100 higher than the recommended water content for PET extrusion. For further analysis, films were extruded and bottles were stretch-blow-molded. Due to polymer degradation and the recycled PET blend viscosity being too low, this material had to be blended with virgin PET in order to be processable. We used 33 wt.-% recycled PET and 66 wt.-% virgin PET ratio. The impact of the thermomechanical stress by multiple extrusions was investigated by several test methods: analysis of the melt pressure in the extruder barrel during extrusion, intrinsic viscosity and melt flow rate, microscopy, differential scanning calorimetry, color value measurements (L*a*b* values), tensile testing, compression testing, and oxygen absorption measurements. The intrinsic viscosity reduced after four re-extrusions in a compounder from 0.82 dl/g to 0.35 dl/g for PET with scavenger and to 0.41 dl/g for pure PET. This, even though low, difference can be explained by the slightly higher PET degradation due to the oxygen scavenger. We found slightly better mechanical properties (yield stress, Young's modulus) for pure PET films compared to PET blended with an oxygen scavenger. At up to three extrusions, there was little influence on these properties. The extruded material with 3 wt.-% oxygen scavenger additive has an oxygen absorption capacity of 9.5 mg oxygen per 1 g of granules, i.e., the scavenger additive absorbed about 300 mg oxygen per 1 g of additive. Our results are relevant for in-house recycling processes of PET with oxygen scavenger. [ABSTRACT FROM AUTHOR]

Hydroxyl (OH) and hydroperoxy (HO2) radicals are central to the understanding of atmospheric chemistry. Owing to their short lifetimes, these species are frequently used to test the accuracy of model predictions and their underlying chemical mechanisms. In forested environments, laser-induced fluorescence–fluorescence assay by gas expansion (LIF–FAGE) measurements of OH have often shown substantial disagreement with model predictions, suggesting the presence of unknown OH sources in such environments. However, it is also possible that the measurements have been affected by instrumental artefacts, due to the presence of interfering species that cannot be discriminated using the traditional method of obtaining background signals via modulation of the laser excitation wavelength (" OH wave "). The interference hypothesis can be tested by using an alternative method to determine the OH background signal, via the addition of a chemical scavenger prior to sampling of ambient air (" OH chem "). In this work, the Leeds FAGE instrument was modified to include such a system to facilitate measurements of OH chem , in which propane was used to selectively remove OH from ambient air using an inlet pre-injector (IPI). The IPI system was characterised in detail, and it was found that the system did not reduce the instrument sensitivity towards OH (< 5 % difference to conventional sampling) and was able to efficiently scavenge external OH (> 99 %) without the removal of OH formed inside the fluorescence cell (< 5 %). Tests of the photolytic interference from ozone in the presence of water vapour revealed a small but potentially significant interference, equivalent to an OH concentration of ∼4×105 molec. cm -3 under typical atmospheric conditions of [ O3 ] =5 0 ppbv and [ H2O ] =1 %. Laboratory experiments to investigate potential interferences from products of isoprene ozonolysis did result in interference signals, but these were negligible when extrapolated down to ambient ozone and isoprene levels. The interference from NO3 radicals was also tested but was found to be insignificant in our system. The Leeds IPI module was deployed during three separate field intensives that took place in summer at a coastal site in the UK and both in summer and winter in the megacity of Beijing, China, allowing for investigations of ambient OH interferences under a wide range of chemical and meteorological conditions. Comparisons of ambient OH chem measurements to the traditional OH wave method showed excellent agreement, with OH wave vs OH chem slopes of 1.05–1.16 and identical behaviour on a diel basis, consistent with laboratory interference tests. The difference between OH wave and OH chem (" OH int ") was found to scale non-linearly with OH chem , resulting in an upper limit interference of (5.0±1.4) ×106 molec. cm -3 at the very highest OH chem concentrations measured (23×106 molec. cm -3), accounting for ∼14 %–21 % of the total OH wave signal. [ABSTRACT FROM AUTHOR]

High concentrations of glutamate induce neurotoxicity by eliciting reactive oxygen species (ROS) generation and intracellular Ca2+ influx. The disruption of Ca2+ homeostasis in the endoplasmic reticulum (ER) evokes ER stress, ultimately resulting in neuronal dysfunction. Additionally, glutamate participates in the development of neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases. Peroxiredoxins (Prxs) are members of a family of antioxidant enzymes that protect cells from neurotoxic factor-induced apoptosis by scavenging hydrogen peroxide (H2O2). Prx4 is located in the ER and controls the redox condition within the ER. The present study investigated the protective effects of Prx4 against glutamate-induced neurotoxicity linked to ER stress. HT22 cells in which Prx4 was either overexpressed or silenced were used to elucidate the protective role of Prx4 against glutamate toxicity. The expression of Prx4 in HT22 cells was significantly increased in response to glutamate treatment, while ROS scavengers and ER chemical chaperones reduced Prx4 levels. Moreover, Prx4 overexpression reduces glutamate-induced apoptosis of HT22 cells by inhibiting ROS formation, Ca2+ influx, and ER stress. Therefore, we conclude that Prx4 has protective effects against glutamate-induced HT22 cell damage. Collectively, these results suggest that Prx4 could contribute to the treatment of neuronal disorders. [ABSTRACT FROM AUTHOR]

The study was focused on the evaluation of two copolymers as micellar carriers for kaempferol delivery. The copolymers comprised identical hydrophilic blocks of poly(2-(dimethylamino)ethyl methacrylate and different hydrophobic blocks of either poly(ε-caprolactone) (PDMAEMA9-b-PCL70-b-PDMAEMA9) or poly(propylene oxide) (PDMAEMA13-b-PPO69-b-PDMAEMA13). The calculation of Flory-Huggins parameters and determination of encapsulation efficiency showed that PDMAEMA-b-PCL-b-PDMAEMA copolymer possessed higher capacity for kaempferol loading. The diameter of the micelles before and after lyophilization was not changed, suggesting that the micelles could be lyophilized and redispersed before administration. The in vitro release of kaempferol from PDMAEMA-b-PPO-b-PDMAEMA micelles was faster than the release from PDMAEMA-b-PCL-b-PDMAEMA micelles, probably due to the higher affinity of kaempferol to this copolymer. Further, the higher affinity resulted in a retention of antioxidant activity of kaempferol in the presence of DPPH and KO2 radicals. Thus, PDMAEMA-PCL-PDMAEMA was considered more appropriate carrier because of the higher encapsulation efficiency and preservation of antioxidant activity of the drug [ABSTRACT FROM AUTHOR]

Jarosite is an effective scavenger for metals by the chemical formula AFe3(SO4)2(OH)6. In the present article, a comprehensive literature review is performed on the formation, decomposition, and utilization of jarosite. Based on reviewed studies, biological jarosite seeds can shorten the induction period and reduce the temperature limit in the jarosite precipitation. Also, the precipitation process of jarosite is more complete with biological jarosite seeds. The crystallization parameters such as Fe2(SO4)3 concentration, agitation speed, pH and temperature have significantly affected on the morphology and the particles size of jarosite. Decomposition of jarosite is carried out using two different methods thermal and hydrothermal. Jarosite seed is a potential resource, which has to be recycled in a technically feasible and environmentally friendly manner. Besides, it is observed that jarosites have several advantages such as control iron in hydrometallurgy, zinc industry, arsenic removal and other impurities, pigment, nanoparticles, filling materials, adsorption materials, acidic reagent, and catalytic materials. [ABSTRACT FROM AUTHOR]

Photocatalysis has emerged as an environmentally friendly technology to develop selective reactions such as the oxidation of alcohol to aldehydes. Graphitic carbon nitride (CN) is a metal-free polymeric structure easily photoactivated under radiation. This work focuses on the enhancement of the photocatalytic activity of bare CN by doping it with phosphorous (P-CN). Different doping levels of P (2–12 wt.) have been explored and the samples were fully characterized by XRD, FTIR, N 2 physisorption, elemental analysis, XPS, DRS-UV–visible, and photoluminescence. A better activity and enhanced selectivity were observed in the P-CN samples if compared to the undoped CN in the oxidation of cinnamyl alcohol to cinnamaldehyde in aqueous solution. The presence of P was demonstrated to contribute to a better delocalization of photo-generated charges. Moreover, the reactivity and selectivity of the CN and P-CN samples were analyzed in water-acetonitrile mixtures, appreciating a better selectivity in the presence of acetonitrile to the detriment of the conversion of the cinnamyl alcohol. The photocatalytic oxidation mechanism over P-CN in aqueous media has been tentatively proposed based on the influence of the reactive oxidative species generated in the process by chemical scavenger tests. They suggested the contribution of superoxide radicals with more selectivity than the photo-generated holes, the second reactive species of importance in the overall oxidation scheme. The contribution of hydroxyl radicals was discharged since its presence was negligible in a probe test based on the formation of 2-hydroxy-terephthalic acid. [Display omitted] • Incorporation of P into graphitic-like carbon nitride attacking C positions. • P-doping enhanced the radiation uptake and noticeably abated the recombination rate. • Presence of optimum P dosage for selective cinnamaldehyde production in aqueous solution. • Essential role played by O 2 • and h+ in aqueous solution, being the HO• negligible. • Selectivity was severely raised in detriment of conversion by using organic solvents. [ABSTRACT FROM AUTHOR]

Interaction of amorphous and crystalline TiO2 ultrafine particles (2–6 nm) with rutin results in the formation of colored nanomaterials of an excellent dispersity and enhanced colloidal stability in aqueous media. The FTIR and Raman spectra confirmed attachment of the rutin ligand via vicinal hydroxyl groups in a catechol-like fashion. The binding of rutin to amorphous TiO2 gives rise to spontaneous crystallization of the parent nanoparticles into hydrogen titanates (H2Ti3O7 and H2Ti12O25). Such structural transformations result in photosensitization toward visible light with enhanced efficiency of the charge separation and interfacial charge transfer processes, confirmed by detailed photoelectrochemical studies of the examined nanomaterials. The effectiveness of the photocatalytic ROS generation reactions was also strongly influenced by hydrogen peroxide, which plays a double role of a reactant prone to reduction and generation of hydroxyl radicals or a redox agent destroying the intra-band gap electronic states, suppressing thereby charge recombination. The photoinduced charge transfer processes lead to generation of various reactive oxygen species, which were detected by EPR using DMPO spin trap (HOO· detection) and in the reaction with terephthalic acid acting as a chemical scavenger (HO· detection). Complexation of TiO2 particles with rutin shifts the photogeneration of hydroperoxyl (HOO·) and hydroxyl (HO·) radicals toward visible light (λ > 400 nm). A triple effect of rutin attachment to titania was established. It consists in pronounced photosensitization, promotion of crystallization and enhancement of the colloidal stability of ultrafine titania particles. Environmental implications of these assets on the photoinduced redox reactions with hydrogen peroxide in aqueous solutions upon UV or visible light irradiation were also discussed. [ABSTRACT FROM AUTHOR]

This study aimed to compare total polyphenol content and antioxidant activity of different forms of Al-Kbous black tea: teabag (TB), loose tea (LT), and opened teabag (OTB). Total polyphenol content was assessed by the Folin-Ciocalteu method, and DPPH and FRAP assays were used to determine antioxidant activity. The results revealed that TB and OTB have significantly more polyphenol than LT at the 5- and 15-minute brewing times. In addition, the data indicated that TB and OTB exhibit significantly greater DPPH radical scavenging activity than LT at all brewing times, while the results of the FRAP assay revealed that TB and LT had significantly greater reducing antioxidant power than OTB at all brewing times. In conclusion, the present results revealed that Al-Kbous black TB brewed for 5-20 minutes produces greater quantities of polyphenol and has either a greater or similar antioxidant capacity in comparison to LT. Additionally, the given results showed no effect on total polyphenol content or the radical scavenging activity of tea extract when prepared by opening the teabag. [ABSTRACT FROM AUTHOR]

Hydrogen sulfide (H2S) is an important signaling molecule whose up‐ and down‐regulation have specific biological consequences. Although significant advances in H2S up‐regulation, by the development of H2S donors, have been achieved in recent years, precise H2S down‐regulation is still challenging. The lack of potent/specific inhibitors for H2S‐producing enzymes contributes to this problem. We expect the development of H2S scavengers is an alternative approach to address this problem. Since chemical sensors and scavengers of H2S share the same criteria, we constructed a H2S sensor database, which summarizes key parameters of reported sensors. Data‐driven analysis led to the selection of 30 potential compounds. Further evaluation of these compounds identified a group of promising scavengers, based on the sulfonyl azide template. The efficiency of these scavengers in in vitro and in vivo experiments was demonstrated. [ABSTRACT FROM AUTHOR]

Plants exposed to hostile environmental conditions such as drought or extreme temperatures usually undergo oxidative stress, which has long been assumed to significantly contribute to the damage suffered by the organism. Reactive oxygen species (ROS) overproduced under stress conditions were proposed to destroy membrane lipids and to inactivate proteins and photosystems, ultimately leading to cell death. Accordingly, considerable effort has been devoted, over the years, to improve stress tolerance by strengthening antioxidant and dissipative mechanisms. Although the notion that ROS cause indiscriminate damage in vivo has been progressively replaced by the alternate concept that they act as signaling molecules directing critical plant developmental and environmental responses including cell death, the induction of genes encoding antioxidant activities is commonplace under many environmental stresses, suggesting that their manipulation still offers promise. The features and consequences of ROS effects depend on the balance between various interacting pathways including ROS synthesis and scavenging, energy dissipation, conjugative reactions, and eventually reductive repair. They represent many possibilities for genetic manipulation. We report, herein, a comprehensive survey of transgenic plants in which components of the ROS-associated pathways were overexpressed, and of the stress phenotypes displayed by the corresponding transformants. Genetic engineering of different stages of ROS metabolism such as synthesis, scavenging, and reductive repair revealed a strong correlation between down-regulation of ROS levels and increased stress tolerance in plants grown under controlled conditions. Field assays are scarce, and are eagerly required to assess the possible application of this strategy to agriculture. [ABSTRACT FROM AUTHOR]

Pt/CeO2 electrocatalysts were coated on the multi-walled carbon nanotube (MWCNT) substrate using a facile electrochemical deposition technique. X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX) were used for characterization the Pt/CeO2/MWCNT catalyst. The electrochemical behavior of prepared electrocatalysts was studied in acidic pH using cyclic voltammetry measurement at ambient temperature. Next, Fenton test was carried out as an ex-situ accelerated experiment for 96 h to investigate the performance Pt/CeO2/MWCNT electrocatalysts in chemical degradation mitigation of Nafion membrane. The impact of adding CeO2 on chemical degradation mitigation of the Nafion was investigated using Fourier-transform infrared spectroscopy (FTIR), fluoride emission rate, weight loss, and SEM tests. Achieved outcomes showed that CeO2 nanoparticles could considerably enhance the chemical degradation mitigation of the Nafion membrane in proton exchange membrane fuel cells (PEMFCs). [ABSTRACT FROM AUTHOR]

Farnesoid X receptor (FXR) agonists play important regulatory roles in bile acid, lipid and glucose metabolism in vitro and in vivo. Thus, FXR agonists exhibit potential therapeutic effects on metabolism-related diseases that are associated with extrahepatic manifestations induced by hepatitis C virus (HCV) infection. This study investigated the effect and mechanism of FXR agonist GW4064 against HCV in vitro to explore the potential application of FXR agonists. Results showed that GW4064 and other FXR agonists have potent antiviral activity against HCV in Huh7.5 cells. GW4064 down-regulated the expression of scavenger receptor class B type I protein via FXR and thereby indirectly inhibited HCV entry into cells, leading to interruption of HCV life cycle. GW4064 also exhibited synergistic anti-HCV effect with known direct-acting antiviral agents (DAAs) used in the clinic and remained sensitive to DAA-resistant HCV mutations. Therefore, FXR agonists are also a kind of antiviral agent, and might be helpful in treatment of HCV-induced hepatic and extrahepatic manifestations. [ABSTRACT FROM AUTHOR]

In this study, a novel Fe–Mn binary oxide (FMBO), which combined the oxidation capability of iron and manganese oxides, was constructed to remove sulfamethoxazole (SMX) effectively using the simultaneous co-precipitation and oxidation methods, and the reaction products were probed by liquid chromatography-mass spectrometry (LC/MS). Particularly, FMBO-mediated transformation mechanisms of SMX were explored using radical scavengers and electron paramagnetic resonance (EPR). Results indicated that the best removal efficiency was obtained at a pH of 4.0, with the H2O2 of 6.0 mmol/L and the FMBO dosage of 2.0 g/L, giving 97.6% removal of 10 mg/L SMX within 60 min. More importantly, we found that the hydroxyl (•OH) radicals generated by FMBO through Fenton-like reaction were responsible for the SMX oxidation. EPR studies were confirmed that the peak intensities of hydroxyl adduct decreased remarkably with increasing pH values. Moreover, the four SMX degradation intermediate products were detected by LC/MS and a reaction pathway for the possible mineralization of SMX, with •OH radicals as the main oxidant, was proposed. These findings provide a novel insight into the removal of SMX by FMBO-mediated radical reactions in aquatic environments. Moreover, this research suggested that FMBO can act as an efficient catalyst to remove SMX in hospital wastewater. [ABSTRACT FROM AUTHOR]

Abstract In this study, the chitosan, chitosan/nano-TiO 2 and chitosan/nano-SiO 2 coating films were prepared, their physico-chemical properties were determined. Then the preservation of Ginkgo biloba seeds coating with these films were investigated during storage. The incorporation of nano-TiO 2 and nano-SiO 2 particles of the best formula enhanced the mechanical properties of the composite films, which improved the water-vapor and gas permeability. Chitosan coating incorporation of nano-TiO 2 and nano-SiO 2 particles could significantly decrease the decay rate, shrinkage rate, respiration rate, ethylene production rate, electrolyte leakage rate, superoxide anion (O 2 · −) production rate and the accumulation of malondialdehyde (MDA) content. After storage, the firmness of G. biloba seeds coated with chitosan alone and chitosan/nanocomposite were markedly higher than those of control. Higher activities of scavenger antioxidant enzymes including peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) were enhanced in the chitosan/nano-TiO 2 and chitosan/nano-SiO 2 coating treatments during storage time. Either the composite treatment of chitosan with nano-TiO 2 or chitosan/nano-SiO 2 exhibited desirable performance in inhibiting mildew occurrence, shrinkage and maintaining the firmness of G. biloba seeds, positively affect the antioxidant activity in G. biloba seeds, thereby leading to the enhancement of seed quality. Coating G. biloba seeds with chitosan/nano-TiO 2 or chitosan/nano-SiO 2 is a potential method for commercial preservation. [ABSTRACT FROM AUTHOR]

BiOI microspheres were synthesized by using mild conditions under microwave irradiation and applying short reaction times. The effect of the reaction medium in the final morphology of BiOI was revised modifying the relative concentrations of 2-propanol and ethylene glycol (EG) used as solvents. The as-prepared samples were characterized by X-ray powder diffraction, scanning electron microscopy, diffuse reflectance spectroscopy, N2 adsorption-desorption isotherms and photoluminescence measurements. The photocatalytic activity of BiOI was evaluated in the oxidation reaction of nitric oxide (NO) under visible-light irradiation. In particular, the samples with morphology of 3D flower-like microspheres prepared with EG showed the highest activity for NO removal (83%), maintaining its performance after several photocatalytic cycles. Besides the morphology of BiOI samples, the high photocatalytic activity was associated with the large surface area and the low rate of charge recombination observed in samples prepared with EG. The use of scavenger agents allowed to determine the predominant participation of holes (h+), electrons (e−) and superoxide ion (·O2−) in the reaction mechanism of the NO oxidation. [ABSTRACT FROM AUTHOR]

Supported cobalt oxides on mesoporous nitrogen-doped carbon (CoxOy/NC) were prepared by a simple pyrolysis method using cobalt acetate as the cobalt source and chitosan as the nitrogen and carbon source. The as-synthesized catalysts were characterized by XRD, N2 adsorption/desorption, SEM, TEM and XPS. It was found that chitosan was transformed to mesoporous carbon after pyrolysis at 900 °C under N2 atmosphere, while Co2+ was reduced to metallic Co covering with cobalt oxide, which was uniformly distributed in the surface of carbon. The catalytic performances were examined by Acid Orange 7 (AO7) degradation with H2O2 as an oxidant in bicarbonate aqueous solution. The dye was decolorized completely after 20 min at room temperature with the CoxOy/NC catalyst. The catalyst can be recycled up to four times without significant loss of activity. The addition of methanol as a hydroxyl radical scavenger confirmed that the radicals take part in the reaction as the major active species. In addition, intermediate products were identified by electrospray ionization-mass spectrometry during the degradation of AO7. [ABSTRACT FROM AUTHOR]

The synthesis of (6-ethyl-1,6-dihydropyrrolo[3,2-c]carbazol-2-yl)methanol 5 and (6-ethyl-6,11-dihydro-1H-dipyrrolo[3,2-c:2′,3′-g]carbazole-2,10-diyl)dimethanol 6 were achieved via the reduction of methyl pyrrolo carbazole carboxylate 3 and methyl dipyrrolo carbazole carboxylate 4, respectively. The structures of hydroxymethyl-pyrrolocarbazoles 5 and 6 were supported by FT-IR, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, 1H and 13C NMR spectroscopy. The photophysical properties of the targeted compounds 3-6 were investigated by employing absorption and fluorescence spectroscopy in different common organic solvents. Also, the fluorescence lifetime (τF) of the compounds was measured utilizing a time-correlated single-photon counting technique in tetrahydrofuran. Antioxidant activities of compounds 3-6 were determined by employing three different assays, namely DPPH radical scavenging, ABTS cation radical decolarization and cupric reducing antioxidant capacity. The results revealed that the ABTS cationic scavenging activity assay was found to be the most sensitive method for the determination of inhibition values. [ABSTRACT FROM AUTHOR]

A deposition method was applied to synthesize a multicomponent photocatalyst based on apatite (HaP)-coated Ag/AgBr/Bi2WO6 (denoted as HaP/Ag/AgBr/Bi2WO6). Various techniques were applied to identify the synthesized photocatalyst. The photocatalytic activity of the prepared photocatalysts was examined using degradation of rhodamine B, methyl orange, and phenol as pollutants under visible-light irradiation. The results of the photocatalytic experiments showed that the HaP/Ag/AgBr/Bi2WO6 multicomponent composite exhibited excellent visible-light-driven photocatalytic activity. Meanwhile, studies on the photocatalytic activity determined that the simultaneous effects of the adsorption properties of HaP, the surface plasmonic resonance of the Ag nanoparticles, the photocatalytic activity of AgBr under visible light, and reactive oxygen species (ROS) contributed to the enhanced photocatalytic activity of the HaP/Ag/AgBr/Bi2WO6 composite. Moreover, based on studies conducted using radical scavengers, the main reactive species in the photocatalytic reaction for degradation of all the chemical pollutants were revealed and a photocatalytic mechanism for the degradation of organics over HaP/Ag/AgBr/Bi2WO6 is proposed. Furthermore, HaP/Ag/AgBr/Bi2WO6 exhibited good stability in cyclic photocatalytic trials. [ABSTRACT FROM AUTHOR]

Highlights • The high eucalyptus productivity indicates a high P scavenger efficiency by accessing successfully the stable P in the soil. • Organic phosphorus comprise an important pool of eucalyptus nutrition in highly weathered soils. • Hedley fractionation was a good indicator of potentially bioavailable P pools for the plant, as well as the citrate + oxalate method. • The available P pool was dependent on inorganic and occluded pools and the organic pool acted predominantly as a sink of P on available and inorganic pools. Abstract Phosphate fertilizers play an important role in plant nutrition. Different P fertilizer sources such as high-solubility (simple superphosphate, SSP), low-solubility (rock phosphate, RP) and complex superphosphate (CSP) are available for plant supplementation. The objective of this study was to investigate the short- and long-term redistribution of soil P after application of different P sources at establishment of an Eucalyptus forest stand. We carried out two experiments to identify the short- and long- term changes in a Brazilian Oxisol. To property identify the P pools in different times, Hadleýs fractionation methodology was applied to a long-term studies and citrate and oxalate to short-term. From zero to 180 days, the soluble P fractions were not altered in the non-fertilized treatment. Under SSP, a slight increase in this P fraction was found until 30 days, followed by a decrease in later evaluations. During the same period, a slight reduction in Pi extracted by citrate and oxalate was found under the control and a large reduction (approximately 50%) under the SSP treatment. Intermediate behavior was observed under the CSP and RP treatments, whereas there was an increase in P-citrate and P-oxalate until 30 days followed by a reduction afterwards. These results suggest that this pool comprises a potential bioavailability of P to plants. Different fertilizer sources did not increase the most recalcitrant P pool. However, different sources increased the organic P pool, mainly organic moderately labile P at long-term evaluations. Organic labile pools showed a fertilizer-specific response where CSP and RP increased respectively by 43% and 41% during the first year, and decreased to 39% in CSP treatment and 50% in RP treatment during the third year. Available P pool was highly dependent on inorganic and occluded pools and the organic pool acted predominantly as a sink of P on available and inorganic pools. The results reinforce the high level of recalcitrance of the organic pool and the fact that Eucalyptus plants must access pools of residual P in order to maintain their nutritional demands. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A simple strategy was proposed to refine persulfate-based Fenton-like system. • Titanium-based Fenton-like system was designed and estimated with two typical pollutants. • {0 0 1}-TiO 2− x /PDS Fenton-like system exhibited good capacity and stability with much reduced matrix effects. • The SO 4 −-mediated mechanisms were elucidated and clearly presented. Abstract Sulfate radical (SO 4 −) based oxidation is an efficient and selective strategy for environmental decontamination. Herein, we confirmed, for the first time, that the fine modulation on semiconducting TiO 2 was able to improve the redox-cycling capability for heterogeneous peroxydisulfate (PDS, S 2 O 8 2−) activation and radicals generation. PDS activation by defective TiO 2− x exposed by high-energy {0 0 1} polar facets was a superior Fenton-like catalytic system for rhodamine B (RhB) and bisphenol A (BPA) degradation, with good activity and selectivity under neutral pH. By radical inhibiting tests with two different scavengers, fluorescence measurements with terephthalic acid and electron paramagnetic resonance (EPR) technique, only the SO 4 − was identified to be the main reactive species from PDS activation on defective TiO 2− x for pollutants degradation. Compared to the reported TiO 2− x /H 2 O 2 system, the proposed TiO 2− x /PDS system exhibited much lower water matrix effects in the presence of four typical anions, natural organic matters and real surface water for target pollutants degradation. The selective SO 4 −-mediated TiO 2− x /PDS catalytic system in natural water matrix and the no toxicity of catalytic material were of considerable interest for practical environmental applications with highly complex chemistry. Our findings elucidated a new strategy for efficient and selective PDS activation based on the defect-related chemistry, which can degrade environmental contaminants and remedy contaminated soil based on sulfate components with much reduced matrix effects. [ABSTRACT FROM AUTHOR]

Carbon nanofibers (CNFs) have been extensively investigated due to their strong uptake and complexation ability. In this work, CNFs was characterized by using SEM, TEM, FTIR, XPS and Raman spectra. The uptake of Co(II) and Ni(II) on bacterium-derived CNFs as a function of contact time, pH, ionic strength and temperature was investigated using batch techniques. The pH-dependent uptake indicated that the uptake of Co(II) and Ni(II) onto CNFs was significantly higher at high pH values than that at low pH values. The uptake of Co(II) and Ni(II) onto CNFs was hardly affected by ionic strength, suggesting the formation of inner-sphere surface complexation of Co(II) and Ni(II) onto CNFs over a wide pH range. The Langmuir model described the uptake of Co(II) and Ni(II) onto CNFs better than the other models did. According to regeneration experiments, CNFs displayed good recoverability and recyclability in the Co(II) and Ni(II) uptake process. The findings presented herein play a significant role in the scavenging of metal ions on inexpensive and available CNFs in environmental cleanup applications. [ABSTRACT FROM AUTHOR]

A sulfite‐based oxygen scavenger (SOS) was developed with sodium metabisulfite and applied to kimchi packaging in an attempt to prevent oxygen‐mediated kimchi quality degradation. The results of the oxygen‐scavenging capacity test showed that the SOS had a competitive oxygen‐scavenging performance in comparison with commercial oxygen scavengers. The kimchi was packaged with and without the SOS and stored over 12 weeks at 0 and 10 °C for an SOS application test. The kimchi treated with the SOS showed a significantly lower (P < 0.05) headspace oxygen and carbon dioxide concentration and pressure inside the packages than the control. The pH and titratable acidity values indicated that the SOS did not retard the kimchi fermentation process. The Hunter L, a, and b values in the kimchi packaged with the SOS were significantly higher (P < 0.05) than those in the control. After 12 weeks of storage, the total aerobic bacteria counts were reduced by 1.32 and 2.97 log CFU/g, lactic acid bacteria counts were reduced by 2.22 and 4.42 log CFU/g, and total yeasts and molds counts were reduced by 1.76 and 3.04 log CFU/g at 0 and 10 °C, respectively, by the SOS compared to those in the control. These results demonstrated that the developed SOS inhibited oxygen‐mediated deterioration of the kimchi, but did not affect the kimchi fermentation. Therefore, our SOS can be used as an active food‐packaging technology for kimchi quality preservation. Practical Application: A newly designed sulfite‐based oxygen scavenger was applied in kimchi packaging, and it showed remarkable preventive effects on the kimchi quality deterioration caused by oxygen. Accordingly, it can be used as an active food‐packaging technology to maintain kimchi quality during the storage period. Moreover, it can also be effectively utilized in the packaging of other high‐moisture foods such as meat, fish, fruits, vegetables, and dairy products. [ABSTRACT FROM AUTHOR]

Graphical abstract Six macrocyclic M(II) complexes with 2-thiofuranmethyl(or 2-furanmethyl, 2-pydinemethyl) functional pendant arms formed five-coordinated mode, which benefits the supply of opened coordinated site to NO molecules. Abstract Four new complexes of Robson-type macrocycles, [CuH(L1)] 2 (ClO 4) 2 (H 2 O) 2 (1), [CuH(L2)] ClO 4 (2), [Cu H(L3)] 2 (ClO 4) 2 (3), [Cu H(L4)] 2 (ClO 4) 2 (CH 3 CH 2 OH) 2 (CH 3 CN) 2 (4) and two reported Robson-type macrocycles polymers {[CuL5](H 2 O) 2 } n (5), {[MnL5](H 2 O) 2 } n (6) were obtained. The ligands (H 2 L1, H 2 L2, H 2 L3) are the products from the condensation between bata and N,N′-bis(3-formyl-5-X-salicylimine)-1,2-ethylenediimine (X = CH 3 , Cl, F), respectively. Ligands H 2 L4 and H 2 L5 are the products of N,N′-bis(3-formyl-5-methylsalicylimine)-1,2-propylenediimineand condensation with bafa and bapa, respectively. All the metal ions have unsaturated coordinated sites, which are available for NO binding. The binding of the complexes with NO molecules have been confirmed by UV–Vis spectrophotometry. The binding constants were calculated to be 1.28 × 103 M−1, 8.9 × 102 M−1, 7.7 × 103 M−1, 1.2 × 103 M−1, 1.2 × 103 M−1, 1.3 × 103 M−1 for 1 , 2 , 3 , 4 , 5 and 6 , respectively. The control experiments revealed there was non-reversible binding of NO, which can be ascribed to specially coordination environment of the central ions. Moreover, the interactions of the complexes with calf thymus DNA (CT-DNA) have been measured by agarose gel electrophoresis, and unobvious DNA cleavage ability of complexes 1 , 3 and 4 indicating no damage to DNA. The results reveal that complexes 1 , 3 and 4 can be served as potential NO scavengers. [ABSTRACT FROM AUTHOR]

Abstract The objective of this work is to further evaluate the performance of the erythorbic acid oxygen scavenger designed by (Kundu and Seiersten, 2017) within 85% wt. Thermally Aged Lean Mono Ethylene Glycol (TAL-MEG). Experiments were performed at two levels of dissolved oxygen concentrations including 1000 ppb and >7500 ppb at pH values of 6, 9 and 11. Furthermore, the erythorbic acid oxygen scavenger was evaluated under conditions representative of an industrial MEG regeneration system in terms of salt and organic acid concentrations to replicate field usage. Strong performance of erythorbic acid in combination with manganese and diethylethanolamine (DEAE) was observed under field conditions suggesting that erythorbic acid may provide an attractive alternative oxygen scavenger for use in the oil and gas industry in place of traditional sulfite based scavengers. However, the results generated within TAL-MEG showed a reduction in the performance of erythorbic acid oxygen scavenger when compared to fresh MEG solution. Moreover, results confirmed that varying acetic acid concentration did not affect oxygen scavenger performance within TAL-MEG. It was observed that the pH of the solution was the primary factor in determining the performance of the erythorbic oxygen scavenger tested with insufficient oxygen removal achieved at a pH of 6. In contrast, strong performance was achieved at pH 9 and 11 successfully reaching below 20 ppb dissolved oxygen concentration within a reasonable timeframe with little to no impact due to the presence of mineral salt ions and organic acids. Highlights • The performance of erythorbic acid has been evaluated within thermally aged MEG. • Strong to acceptable oxygen removal performance was demonstrated at pH of 11 and 9. • The erythorbic acid demonstrated poor oxygen removal performance at a pH of 6. • Little to no impact observed due to the presence of mineral ions or acetic acid. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

A series of 4-(substituted benzylidene-amino)-2,3-dimethyl-1-phenyl- 3-pyrazoline-5-ones (3a-l) was obtained using sonochemical assisted reaction. The synthesized Schiff bases were evaluated for their antiviral, antibacterial, anticandida, DPPH scavenging and anti-tyrosinase activities in vitro. The antimicrobial screening results revealed that amongst the tested imines, compound 3l appeared to be а promising one (with a minimal inhibitory concentration 47 ug/ml). The most potent DPPH scavengers were azometines 3a and 3g. No significant inhibition on the monophenolase activity in vitro of mushroom tyrosinase was observed. [ABSTRACT FROM AUTHOR]

Graphical abstract A series of novel benzoisoselenazol-containing arenobufagin hybrids were designed, synthesized and their in vitro cytotoxicity for cancer cell lines and AC16 cell line, as well as their ROS scavenge activities were evaluated. Among them, 6d and 6f exhibited ROS scavenge activities and less cardiotoxcity. Highlights • A series of novel benzoisoselenazol-containing arenobufagin hybrids (6a – 6f) were synthesized by employing a linker of natural amino acid. • The in vitro cytotoxicity against three human cell lines and ROS scavenge activities were tested. • Two hybrids (6d and 6f) with well ROS scavenge activities and less cardiotoxicity were identified. Abstract Arenobufagin is a naturally occurring bufadienolide showing promising antitumor activity accompanied however with apparent cardiac toxicity. Following the recent discovery that oxidative damage possibly be an important cause of the cardiac toxicity of cardenolides, a strategy fusing the antitumor agent arenobufagin with a benzoisoselenazol fragment, a reactive oxygen species (ROS) scavenger, has been developed. Six novel hybrids were synthesized and their ROS scavenging activities as well as their in vitro cytotoxicity against the human hepatocellular carcinoma cell line HepG2, an adriamycin-resistant subline HepG2/ADM, and the human myocardial cell line AC16 were evaluated. The results indicate that the hybrids exhibit various degrees of in vitro ROS scavenging activities, and weaker cytotoxicity than that of arenobufagin against the myocardial cell line AC16. These findings suggest the feasibility of a strategy in which the cardiotoxicity of the potential antitumor agent arenobufagin is reduced. [ABSTRACT FROM AUTHOR]

Aims: To investigate the effect of a free radical scavenger (tempol) after relief of partial bladder outlet obstruction (pBOO) on bladder function in a rat model. Methods: pBOO was induced in 50 eight-week-old female Sprague-Dawley rats and relieved 3 weeks later. The rats were divided randomly into 5 groups: sham-operated, tempol-treated for 1 week (Treat-1w) or 3 weeks (Treat-3w), and no treatment for 1 week (nonTreat-1w) or 3 weeks (nonTreat-3w). Awaken cystometrograms were obtained 1 or 3 weeks after relief according to the grouping. The bladders were isolated and weighed. H&E, Masson’s trichrome and TUNEL staining were used to analyze histological changes. The oxidative stress assessed using malondialdehyde. The expression of beta-3 adrenoreceptor was examined by Western blotting. Results: The tempol-treated groups exhibited a significant decrease in the number of non-voiding contractions per voiding cycle (nonTreat-1w vs. Treat-1w, 1.18±0.82 vs. 0.36±0.40, P = 0.010; nonTreat-3w vs. Treat-3w, 1.51±0.69 vs. 0.23±0.25, P = 0.002). The thickness and collagen fiber deposition of the detrusor muscle layer was significantly decreased in the treated groups. Apoptosis detected was mainly observed in the urothelial cell layer, although the rate of apoptosis was significantly decreased in the treated groups (48.9±3.36% vs. 32.7±11.10%, P = 0.024; 25.8±4.67% vs. 15.7±9.83%, P = 0.314). The tempol-treated groups showed significant decreases in the MDA concentrations at both 1 and 3 weeks after relief. The expression of the beta-3 adrenoreceptor was increased in the tempol-treated rats. Conclusions: Ischemic reperfusion injury after relief of pBOO caused histological and functional changes in the bladder. Free radical scavenger treatment prevented this oxidative stress. [ABSTRACT FROM AUTHOR]