Absence Of Peroxide Research Articles

LI-ION BATTERY RECYCLING AT PILOT SCALE: DEMONSTRATING THE RESYNTHESIS ROUTE ALSO FOR NMC-LFP MIXED BLACK MASS

The hydrometallurgical recycling of end-of-life Li-ion batteries constitutes a sustainable path for the integral recovery of battery components. However, the heterogeneity of electrode materials constitutes a limitation for process optimization that must provide robust and flexible strategies. In this work, the preliminary results obtained as part of the demonstration activities of the LIFE DRONE project are reported with particular attention to the possibility of integrating the recycling process based on the resynthesis of NMC (Nickel Manganese Cobalt) cathodes with the treatment of mixed black mass also containing LFP (Lithium Ferrous Phosphate) electrodic powders. The experimental results obtained highlight the possibility of leaching NMC black mass in the absence of hydrogen peroxide when NMC-LFP mixtures are used with almost quantitative extraction yields of metals. In particular, working without H2O2 at 60°C for 3 h the following yields of extraction were obtained: 89% for Ni, 69% for Mn, 89% for Co, 91% for Li, 90% for Fe, 100% for P, 56% for Al and 32% for Cu. Furthermore, the experimental data showed that by varying the pH of the leach liquor, it is possible to separate selectively iron phosphate by quantitative precipitation (100% for Fe, 100% for P and 60% for Al) before proceeding with NMC resynthesis.

Novel Immunosensor Based on Metal Single-Atom Nanozymes with Enhanced Oxidase-Like Activity for Capsaicin Analysis in Spicy Food.

Capsaicin (CAP) is a primary indicator for assessing the level of pungency. Herein, iron-based single-atom nanozymes (SAzymes) (Fe/NC) with exceptional oxidase-like activity were used to construct an immunosensor for CAP analysis. Fe/NC could imitate oxidase actions by transforming O2 to •O2- radicals in the absence of hydrogen peroxide (H2O2), which could avoid complex operations and unstable results. By regulating the Fe atom loads, an optimal Fe0.7/NC atom usage rate could improve the catalytic activity (Michaelis-Menten constant (Km) = 0.09 mM). Fe0.7/NC was integrated with goat antimouse IgG by facile mix incubation to develop a competitive enzyme-linked immunosorbent assay (ELISA). Our Fe0.7/NC immunosensing platform is anticipated to outperform the conventional ELISA in terms of stability and shelf life. The proposed immunosensor provided color responses across 0.01-1000 ng/mL CAP concentrations, with a detection limit of 0.046 ng/mL. Fe/NC may have potential as nanozymes for CAP detection in spicy foods, with promising applications in food biosensing.

Rational Design of Enzymatic Electrodes: Impact of Carbon Nanomaterial Types on the Electrode Performance

This research focuses on the rational design of porous enzymatic electrodes, using horseradish peroxidase (HRP) as a model biocatalyst. Our goal was to identify the main obstacles to maximizing biocatalyst utilization within complex porous structures and to assess the impact of various carbon nanomaterials on electrode performance. We evaluated as-synthesized carbon nanomaterials, such as Carbon Aerogel, Coral Carbon, and Carbon Hollow Spheres, against the commercially available Vulcan XC72 carbon nanomaterial. The 3D electrodes were constructed using gelatin as a binder, which was cross-linked with glutaraldehyde. The bioelectrodes were characterized electrochemically in the absence and presence of 3 mM of hydrogen peroxide. The capacitive behavior observed was in accordance with the BET surface area of the materials under study. The catalytic activity towards hydrogen peroxide reduction was partially linked to the capacitive behavior trend in the absence of hydrogen peroxide. Notably, the Coral Carbon electrode demonstrated large capacitive currents but low catalytic currents, an exception to the observed trend. Microscopic analysis of the electrodes indicated suboptimal gelatin distribution in the Coral Carbon electrode. This study also highlighted the challenges in transferring the preparation procedure from one carbon nanomaterial to another, emphasizing the importance of binder quantity, which appears to depend on particle size and quantity and warrants further studies. Under conditions of the present study, Vulcan XC72 with a catalytic current of ca. 300 µA cm−2 in the presence of 3 mM of hydrogen peroxide was found to be the most optimal biocatalyst support.

A Study on the Lateral Channel of Scytalidium Catalase

Catalases are antioxidant enzymes. Their main function is to convert hydrogen peroxide, one of the reactive oxygen species, into water and oxygen. A bifunctional catalase enzyme from Scytalidium thermophilum, which belongs to the monofunctional catalase family, exhibits oxidase activity in the absence of hydrogen peroxide without the need for a cofactor. It is able to oxidize a variety of ortho- and para-diphenolic compounds, but the oxidase activity is very low (~ 10,000-fold) compared to its main activity in peroxide degradation. In this study, an attempt was made to improve the oxidase activity of catalase for its industrial utilization. For this purpose, the residues located in the lateral channel (H214, D224, and K248), which are thought to play an important role in the access of oxidase substances to the active site, were selected and converted into an amino acid with a smaller side chain -Ala- by site-directed mutagenesis. The changes in the catalytic efficiency of the variants were evaluated by spectrophotometric analysis. The results showed that oxidase activity was increased two- to threefold in all variants, while some exhibited decreased catalase activity. The D224A variant gave the best results as it showed approximately 2-fold increase in oxidase activity without loss of catalase activity (about 92% of the wild-type catalase activity was retained). Thus, a protein variant with improved properties was successfully produced.

Functional characterization of a catalase gene PtCat associated with sclerotia formation in Pleurotus tuber-regium.

Pleurotus tuber-regium (Fr.) Sing. can evade oxygen by forming sclerotia under oxidative stress, consequently averting the development of hyperoxidative state, during which the expression level of catalase gene (PtCat) is significantly up-regulated. To investigate the relationship between the catalase gene and sclerotia formation, over-expression and interference strains of the PtCat gene were obtained by Agrobacterium tumefaciens-mediated transformation for phenotypic analysis. In the absence of hydrogen peroxide (H2O2) stress, a minor difference was observed in the mycelial growth rate and the activity of antioxidant enzymes between the over-expression and interference strains. However, when exposed to 1-2mM H2O2, the colony diameter of the over-expression strain was approximately 2-3× that of the interference strain after 8days of culturing. The catalase activity of the over-expression strain increased by 1000U/g under 2mM H2O2 stress, while the interference strain increased by only 250U/g. After one month of cultivation, the interference strain formed an oval sclerotium measuring 3.5cm on the long axis and 2cm on the short axis, while the over-expression strain did not form sclerotia. Therefore, it is concluded that catalase activity regulates the formation of sclerotia in P. tuber-regium.

ANTIPROLIFERATIVE AND ANTIOXIDANT EFFECTS OF CARNOSIC ACID ON HUMAN LIVER CANCER CELLS

The purpose of the study was to investigate the cytotoxic effects of carnosic acid alone and in combination with cisplatin on human liver cancer cells and their capacity to scavenge reactive oxygen species induced in the presence or absence of hydrogen peroxide.Cytotoxic effects of agents on human liver cancer cells for 24 and 48 hours were evaluated by methyl-thiazol tetrazolium-bromide assay. Mitochondrial membrane potential were detected JC-1 kit. The intracellular reactive oxygen species levels were determined using 2’-7’dichlorofluorescin diacetateassay. According to our findings, both carnosic acid alone and in combination with cisplatin showed cytotoxic effects in human liver cancer cells at 24 and 48 hours of exposure. In particular, it was seen that the cell viability significantly decreased in a dose-dependent manner at 48 hours of exposure, and the combined treatment was found to have a more pronounced cytotoxic effect. In addition, all carnosic acid concentrations alone and in combination with cisplatin were identified to significantly reduce mitochondrial membrane potential. We observed that both carnosic acid alone and in combination with cisplatin lowered intracellular reactive oxygen species levels in the presence or absence of hydrogen peroxide. The results suggested that carnosic acid alone or in combination with cisplatin might be a promising agent in the treatment of liver cancer.

Systematic identification and characterization of five transcription factors mediating the oxidative stress response in Candida albicans

Candida albicans is an opportunistic human fungal pathogen that causes superficial and systemic infections, particularly in immunocompromised individuals. In response to C. albicans infection, innate immune cells of the host produce and accumulate reactive oxygen species (ROS), which can lead to irreversible damage and apoptosis of fungal cells. Several transcription factors involved in this oxidative stress response have been identified; however, a systematic study to identify the transcription factors that mediate the oxidative stress response has not yet been conducted. Here, we screened a comprehensive transcription factor mutant library consisting of 211 transcription factor deletion mutant strains in the presence and absence of hydrogen peroxide (H2O2), a potent ROS inducer, and identified five transcription factors (Skn7, Dpb4, Cap1, Dal81, and Stp2) that are sensitive to H2O2. Genome-wide transcriptional profiling revealed that H2O2 induces a discrete set of differentially regulated genes among the five identified transcription factor mutant strains. Functional enrichment analysis identified KEGG pathways pertaining to glycolysis/gluconeogenesis, amino sugar and nucleotide sugar metabolism, and ribosome synthesis as the most enriched pathways. GO term analysis of the top common differentially expressed genes among the transcription factor mutant strains identified hexose catabolism and iron transport as the most enriched GO terms upon exposure to H2O2.This study is the first to systematically identify and characterise the transcription factors involved in the response to H2O2. Based on our transcriptional profiling results, we found that exposure to H2O2 modulates several downstream genes involved in fungal virulence. Overall, this study sheds new light on the metabolism, physiological functions, and cellular processes involved in the H2O2-induced oxidative stress response in C. albicans.

Nano-ferroelectric oxidase mimics for colorimetric detection of glutathione

The oxidase-mimicking activity of ferroelectric BaTiO3 nanoparticles (BTO NPs) is reported. In the absence of hydrogen peroxide or oxygen, BTO NPs catalyzed the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) and other chromogenic substrates. The catalytic constant (Kcat) was eight times that of fluorescein and 104 times that of bovine serum albumin-protected Se nanozymes. In the mechanism of the chromogenic reaction catalyzed by BTO NPs, the intrinsic electric field of the ferroelectric BTO drove the separation of holes and electrons, and the separated carriers reacted with water to produce reactive oxygen species that oxidized the chromogenic substrates. The BTO NPs-TMB chromogenic system was used to detect glutathione, which restored the blue-colored oxidized TMB to its colorless initial state. There was a good linear relationship between the absorbance change and the GSH concentration over the range 0.50–20 μM, with a 0.2-μM limit of detection. This work not only proposed a new idea of screening and designing nanozymes from ferroelectric materials but also expand the application of ferroelectric nanomaterials to bio-detection.

Peptide extract from spent yeast improves resistance of Saccharomyces cerevisiae to oxidative stress

Yeast cells face various stress factors during industrial fermentations, since they are exposed to harsh environmental conditions, which may impair biomolecules productivity and yield. In this work, the use of an antioxidant peptide extract obtained from industrial spent yeast was explored as supplement for Saccharomyces cerevisiae fermentation to prevent a common bottleneck: oxidative stress. For that, a recombinant yeast strain, producer of β-farnesene, was firstly incubated with 0.5 and 0.7 g/L peptide extract, in the presence and absence of hydrogen peroxide (an oxidative stress inducer), for 1–5 h, and then assayed for intracellular reactive oxygen species, and growth ability in agar spot assays. Results showed that under 2 mM H2O2, the peptide extract could improve cells growth and reduce reactive oxygen species production. Therefore, this antioxidant effect was further evaluated in shake-flasks and 2-L bioreactor batch fermentations. Peptide extract (0.7 g/L) was able to increase yeast resistance to the oxidative stress promoted by 2 mM H2O2, by reducing reactive oxygen species levels between 1.2- and 1.7-fold in bioreactor and between 1.2- and 3-fold in shake-flask fermentations. Moreover, improvements on yeast cell density of up to 1.5-fold and 2-fold, and on biomolecule concentration of up to 1.6-fold and 2.8-fold, in bioreactor and shake-flasks, respectively, were obtained. Thus, culture medium supplementation with antioxidant peptide extracted from industrial spent yeast is a promising strategy to improve fermentation performance while valuing biomass waste. This valorization can promote a sustainable and eco-friendly solution for the biotechnology industry by the implementation of a circular economy model.Key points• Peptide extract from spent yeast applied for the first time on yeast fermentation.• Antioxidant peptide extract enhanced S. cerevisiae oxidative stress resistance.• Fermentation performance under stress improved by peptide extract supplementation.

The Distinction between Dematiaceous Molds and Non-Dematiaceous Fungi in Clinical and Spiked Samples Treated with Hydrogen Peroxide Using Direct Fluorescence Microscopy

Dematiaceous fungi are pigmented molds with a high content of melanin in their cell walls that can cause fatal infections in immunocompromised hosts. Direct microscopy is the main method for the rapid diagnosis of dematiaceous fungi in clinical specimens. However, it is often difficult to distinguish their hyphae from non-dematiaceous hyphae and yeast pseudohyphae. Our aim was to develop a fluorescence staining method that targets melanin for the detection of dematiaceous molds in clinical specimens. Glass slide smears of clinical samples and sterile bronchoalveolar lavage spiked with dematiaceous and non-dematiaceous fungi were treated with hydrogen peroxide, and digital images were recorded using direct microscopy with different fluorescent filters. The images of fungi were compared for their fluorescence intensity using the NIS-Elements software. The fluorescent signal between dematiaceous and non-dematiaceous fungi demonstrated a markedly increased mean intensity for dematiaceous molds following hydrogen peroxide treatment (7510.3 ± 10,427.6 vs. 0.3 ± 3.1, respectively, p < 0.0001). No fluorescent signal was detected in the absence of hydrogen peroxide. "Staining" fungal clinical specimens with hydrogen peroxide, followed by fluorescence microscopy examination, can differentiate between dematiaceous and non-dematiaceous fungi. This finding can be used for the detection of dematiaceous molds in clinical specimens and enables the early and appropriate treatment of infections.

Application of amino acids for gold leaching: Effective parameters and the role of amino acid structure

The main objective of this research work was to employ different amino acids, and investigate on their capability in gold extraction by leaching process. For this purpose, 8 amino acids (Glycine, Alanine, Valine, Phenyl Alanine, Histidine, Asparagine, Aspartic Acid, and Cysteine) were used to leach native gold and various effective parameters were accordingly verified. The studied parameters were temperature, hydrogen peroxide concentration (as oxidant agent), pH and amino acid concentration. The obtained results indicated that the existence of hydrogen peroxide, moderate temperature, and alkaline pH were the key factors for gold leaching, using amino acids except for Cysteine which could dissolve gold at ambient temperature and in absence of hydrogen peroxide. It was also concluded that the order of amino acids in gold leaching was: Asparagine > Glycine > Histidine > Cysteine > Phenyl Alanine > Valine > Aspartic acid > Alanine. Comparing the leaching rates with related amino acids molecular structures, showed that aliphatic and aromatic amino acids were the lowest effective agents and the existence of N, O, and S donor atoms on the amino acid carbon side chain could be considered as the sign of higher ability for complexing with gold. However, it was also found that the amino acids with just COO− group(s) on the side chain could not dissolve gold effectively. It was also found that all of amino acids are degraded and polymerized during gold dissolution (except Glycine) which leads to spoiling of the agent and has a negative effect on dissolution.

Facile synthesis and characterization of Fe2O3 nanoparticles using L-lysine and L-serine for efficient photocatalytic degradation of methylene blue dye

In this work, Fe 2 O 3 nanoparticles, abbreviated as OL and OS, were facilely synthesized by the combustion procedure using L-lysine and L-serine as organic fuels, respectively. Also, the OL and OS samples were identified using different instruments such as Raman spectrometer, FT-IR spectrophotometer, UV–Vis spectrophotometer, XRD, HR-TEM, BET surface area, and FE-SEM. The XRD confirmed that the mean grain size of OL and OS samples is 42.23 and 33.16 nm, respectively. The HR-TEM images confirmed that irregular, hexagonal, and spherical shapes, have an average diameter of 39.13 and 34.28 nm, were observed in the OL and OS samples, respectively. The BET surface area of the OL and OS samples is 16.20 and 28.34 m 2 /g, respectively. Additionally, the OL and OS samples were accomplished for the photocatalytic degradation of methylene blue dye in the absence and presence of hydrogen peroxide. The % degradation of 45 mL of 25 mg/L of methylene blue dye in the case of using OL and OS samples in the absence of hydrogen peroxide is 55.23 and 63.64 % after 120 min, respectively. Also, in the presence of hydrogen peroxide, the % degradation in the case of using OL and OS samples is 100 % after 35 and 25 min, respectively.

Degradation of dye wastewater by using cobalt, copper and nickel Schiff base complexes as catalysts: spectral, molecular modelling, catalytic activity and metal removal from aqueous solution

ABSTRACT Metal complexes of Co(II), Cu(II) and Ni(II) with the Schiff base ligand, 6,6ʹ-(([1,1ʹ-biphenyl]-4,4ʹ diylbis(azaneylylidene))bis(methaneylylidene))bis(2,4-dichlorophenol) (H2L) were synthesised. All synthesised compounds were identified and characterised. The conductivity measurements showed the non-electrolytic nature of all the complexes. The decomposition of all complexes ended with metal oxide. Octahedral geometries were proposed for all complexes. Photocatalytic degradation of methylene blue dye (MB) in the presence and absence of hydrogen peroxide was studied by using Co(II), Cu(II) and Ni(II) complexes as catalysts. Fluorescence studies have shown that the reported compounds can act as photoactive materials. Density functional theory was used to investigate the geometries of the ligand and its complexes. The adsorption of Co2+, Ni2+ and Cu2+ in an aqueous solution on H2L ligand under various conditions was studied. The optical properties of all complexes were studied. Antimicrobial activities of the ligand and its transition metal complexes were studied. The in-vitro cytotoxicity of ligand and its cobalt(II), nickel(II) and copper(II) complexes were evaluated towards the human Liver Carcinoma (HepG2) cell line and compared with standard cisplatin.

Development of floating 3D-microfloral CuO-polysulfone beads for wastewater treatment

Sustainable recycling of earth-abundant transition metals and water-overwhelming macroplastics are currently needed to alleviate depletion of resources and risks posed against environmental sustainability and health. In this contribution, copper metal recovered from an electronic waste was used to fabricate microfloral copper(II)oxide (CuO) particles via an anodized metastable pathway. Interaction of the latter with hot polysulfone in dimethylsulfoxide (DMSO) led to the formation of a floating photocatalyst via a non-solvent phase separation. The catalyst was used for the degradation of humic acid and flavonoid dyes in the presence or absence of hydrogen peroxide (H2O2), a light-emitting diode (LED) and sunlight. A pyramidal triangular model was used to predict the life cycle of H2O2 while an enhanced photocatalytic property was observed after irradiation with light. The as-synthesized materials showed attractiveness for the degradation of phenolic and carboxylic acid-bearing organic pollutants in water.

High sensitivity and rapid detection of hepatitis B virus DNA using lateral flow biosensors based on Au@Pt nanorods in the absence of hydrogen peroxide.

Nanozymes are a kind of nanomaterial with enzymatic activity, and have attracted wide attention in signal probe fields owing to their good catalytic activity and stability. Herein, we designed gold@platinum nanorods (Au@Pt) with enhanced oxidase-like activity as signal probes to construct lateral flow biosensors (LFBs) for the detection of hepatitis B virus DNA (HBV-DNA). The enhanced oxidase-like activity of Au@Pt nanorods can effectively catalyze the oxidation of 3,3',5,5'-tetramethylenebenzidine (TMB) to a blue substrate in the absence of hydrogen peroxide (H2O2). Based on this principle, LFBs using Au@Pt nanorods as signal probes can provide an effective signal amplification strategy and prevent biomolecules from being affected by H2O2. Under optimal conditions, LFBs have a good linear relationship between 0.1 nM and 50 nM, and the calculated detection limit was 8.5 pM. The technological strategy in the detection and quantification of HBV-DNA in this work may be helpful to achieve a rapid and accurate diagnosis of early HBV-DNA and provide new ideas for the development of point-of-care testing.

Cobalt-decorated 3D hybrid nanozyme: A catalytic amplification platform with intrinsic oxidase-like activity

Research about constructing multi-dimensional carbon nanomaterials is of great significance in electrocatalytic and sensing fields in order to integrate structural merits of each individual unit. Also, nanomaterials with enzyme-like activities are prospective candidates for artificial enzyme design and electrochemical application. Herein, we fabricate Co, N co-doped hierarchical hybrid (Co@NCNTs/NC) nanozyme, which integrates of both N-doped carbon nanotubes (NCNTs) and N-doped carbon sheets (NC). The three-dimensional (3D) porous carbon composite is prepared by thermal treatment of metal-organic framework (MOF) which was synthesized by growing of ZIF-67 on ZIF-L at room temperature. The obtained nanomaterial not only possesses an improved oxidase-like activity that can catalyze 3,3′,5,5′-tetramethylbenzidine (TMB) in the absence of hydrogen peroxide (H2O2), but also constructs a signal amplification platform towards dopamine (DA) due to the synergistic catalysis of Co species and N-doped porous carbon architecture. The electrocatalytic performance for DA detection shows a broad linear range from 30 nM to 710 μM and a detection limit of 9 nM. The Co@NCNTs/NC/GCE is employed to practically detect DA in human serum and artificial cerebrospinal fluid (aCSF) samples with satisfactory results. The present work exhibits a great promising in colorimetric and electrochemical sensing fields and presents a new sight for the fabrication of MOF-derived nanozyme.

Assessment of the compounds formed by oxidative reaction between p-toluenediamine and p-aminophenol in hair dyeing processes: Detection, mutagenic and toxicological properties

Previous studies have demonstrated the presence of precursors and coupling agents in wastewater from hair dyeing processes. The complex reaction involved in the oxidation of these compounds can generate extremely hazardous sub-products, leading to an increase in the mutagenicity and toxicity of wastewater. Without proper treatment, this highly toxic wastewater may find its way into the drinking water treatment plant. The present work aimed to investigate the main products generated after the oxidation reaction involving p-toluenediamine (PTD) and p-aminophenol (PAP) – precursors that widely used in the composition of commercial permanent hair dyes, under experimental conditions close to the routine hair dyeing process (in the presence and absence of hydrogen peroxide in ammoniacal medium), using spectroscopic techniques. The study also investigated the mutagenicity and toxicity of the products formed in the hairdressing wash water and conducted detection analysis to determine the presence of the precursors and Bandrowski's Base Derivative (BBD) in samples of wastewater, surface and drinking water using HPLC-DAD and linear voltammetry techniques. Based on this investigation, we identified several PTD and PAP self-oxidation products and eleven sub-products derived from the reaction between PTD and PAP. Assays conducted using Salmonella typhimurium YG1041, with and without activation-induced rat liver metabolism (S9), indicated mutagenicity of the reaction products in concentrations above 10.0 μg μL−1. The concentrations of PTD, PAP, and several reactions and oxidation products of these precursors were detected in wastewater and water samples.

Synergistic induction of TNF-α by palmitate and oxidative stress in human monocytic cells involves the NF-κB/p38 MAPK signaling

Abstract Tumor necrosis factor (TNF)-α is a key proinflammatory cytokine expressed in obesity/ type-2 diabetes. In metabolic disease conditions, TNF-α is co-expressed with increased circulatory levels of free fatty acids, such as long-chain unsaturated fatty acid palmitate. The hypoxic milieu in the adipose tissue is known to exert oxidative stress. Although it is known that palmitate may induce TNF-α in different cell types, it still remains unclear whether the oxidative stress could augment TNF-α expression in human monocytic cells, and thus exacerbate metabolic inflammation. To test the hypothesis, THP-1 monocytic cells were stimulated with palmitate, in presence or absence of hydrogen peroxide (H2O2) or 1% hypoxia. TNF-α, CHOP, ERN1, and HIF-1α mRNA expression was assessed by qRT-PCR; TNF-α protein expression was detected by flow cytometry/ immunohistochemistry; reactive oxygen species (ROS) expression was measured by DCFH-DA assay; and NF-κB/p38 MAPK phosphorylation was detected by western blotting. We found that TNF-α mRNA and protein expression were significantly upregulated in THP-1 cells co-stimulated with palmitate and H2O2/hypoxia. TNF-α expression associated positively with intracellular ROS, transcripts of CHOP, ERN1, HIF-1α, and phosphorylation of NF-κB/p38 MAPK. Synergistic TNF-α expression co-induced by palmitate and H2O2/hypoxia was diminished by cell treatments with curcumin, apocynin, or N-acetyl cysteine (P&amp;lt;0.01). In conclusion, palmitate and oxidative stress promote the TNF-α expression in human monocytic cells via the mechanisms involving ER stress, HIF-1α stabilization, and NF-κB/p38 MAPK signaling. These findings may have pathophysiological significance in metabolic inflammatory conditions.

Removal of Organic Micropollutants from Treated Municipal Wastewater by O3/UV/H2O2 in a UVA-LED Reactor

ABSTRACT Organic micropollutants (OMPs) have been widely detected in the aqueous environment and their effect on the environment and human health has been studied. The removal of OMPs from effluents of a conventional urban wastewater treatment plant by ozonation as well as photo-enhancement of ozonation using UVA-LED panels and photolysis in the presence and absence of hydrogen peroxide was investigated. In a novel semi-technical reactor municipal wastewater was treated for 2 hours, using ozone – O3 (3 mg O3·L−1) and in combination with UVA-LED – O3/UV (peak wavelength 371 nm, 0.78 W·m−2) and in combination with UVA-LED and hydrogen peroxide – O3/UV/H2O2 (20 mg H2O2·L−1). The highest removal fractions for all OMPs were obtained with O3/UV/H2O2 (candesartan: 93.3%, irbesartan: 79.9%, 1 H-benzotriazole: 42.2%, hydrochlorothiazide: 40.8%, 4-/5-methyl-1 H-benzotriazole: 39%, and metoprolol: 24%) and with O3 (diclofenac: 87.2%, carbamazepine: 76.4%, and sulfamethoxazole: 53.5%). As a conclusion of the different AOP combinations of this study, UV photo-enhancement of ozonation has much more beneficial effects on OMP removal when it is combined with an additional H2O2 dosing.

Fluorophore-Dapagliflozin Dyad for Detecting Diabetic Liver/Kidney Damages via Fluorescent Imaging and Treating Diabetes via Inhibiting SGLT2.

Type II diabetes is a prevalent disease; if left untreated, it could cause serious complications including liver and kidney damages. Hence, early diagnosis for these damages and effective treatment of diabetes are of high importance. Herein, a fluorophore-dapagliflozin dyad (DX-B-DA) has been developed as a theranostic system that can be triggered by intrahepatic/intrarenal reactive oxygen species (ROS) to concomitantly release a near-infrared (NIR) fluorescent dye (DX) and a SGLT2 inhibitor dapagliflozin (DA). In this dyad (DX-B-DA), the NIR fluorophore (DX) and the drug DA were covalently linked through a boronate ester bond which serves as the fluorescence quencher as well as the ROS-responsive moiety that can be cleaved by pathological levels of ROS in diabetics. The in vitro experiments indicate that, in the absence of hydrogen peroxide, the dyad is weakly emissive and keeps its drug moiety in an inactive state, while upon responding to hydrogen peroxide, the dyad simultaneously releases the NIR dye and the drug DA, suggesting that it can serve as an activatable probe for detecting and imaging diabetic liver/kidney damages as well as a prodrug for diabetes treatment upon being triggered by ROS. The dyad was then injected in mouse model of type II diabetes, and it is found that the dyad can not only offer visualized diagnosis for diabetes-induced liver/kidney damages but also exhibit high efficacy in treating type II diabetes and consequently ameliorating diabetic liver/kidney damages.