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1.
Sci Total Environ ; 950: 175288, 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-39111419

RESUMEN

Widely employed nitrophenols (NPs) are refractory and antioxidant due to their strong electron-withdrawing group (-NO2). Actually, NPs are readily reduced to aminophenols (APs). However, APs remain toxic and necessitate further treatment. Herein, we utilized a novel sequential reduction-oxidation system of carbon-modified zero-valent aluminum (C@ZVAl) combined with persulfate (PS) for the thorough removal of both NPs and APs. The results demonstrated that p-nitrophenol (PNP, up to 1000 mg/L) exhibited complete reduction to p-aminophenol (PAP), and then over 98.0 % of PAP could be effectively oxidized, in the meantime the removal rate of chemical oxygen demand (COD) was as high as 95.9 %. Based on the SEM and XPS characterizations, we found that C@ZVAl has exceptionally high reactivity that generates massive electrons and reduces PNP to PAP through accelerated electron transfer. In the subsequent oxidation step, PS can be rapidly activated by C@ZVAl to generate SO4- radicals for PAP oxidization. Meanwhile, the mineralization of COD proceeds. The temporal binding of reduction and oxidation can be regulated by varying the PS dosing time. Namely, the appropriate delay in PS dosing facilitates sufficient reduction to provide enough reactants for oxidation, favoring the mineralization of PNP and COD. More crucially, dinitrodiazophenol (DDNP) in an actual explosive wastewater without any pretreatment can be effectively mineralized by this sequential reduction-oxidation system, affirming the excellent performance of this process in practical applications. In conclusion, the C@ZVAl-PS based sequential reduction-oxidation looks very promising for enhanced mineralization of nitro-substituted organic contaminants.

2.
Nanotechnology ; 35(34)2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38788702

RESUMEN

As a promising alternative to Ir based acidic oxygen evolution reaction (OER) catalysts, Ru suffers from severe fading issues. Supporting it on robust oxides such as TiO2is a simple and effective way to enhance its lifetime. Here, we find that a simple reduction-oxidation process can further improve both activity and stability of RuO2-TiO2composites at high potentials. In this process, the degree of oxidation was carefully controlled to form Ru/RuO2heterostructure to improve OER activity. Moreover, due to the oxophilicity difference of Ru and Ti, the structure of catalysts was changed from supported to embedded, which enhanced the protective effect of TiO2and mitigated the dissolution of Ru element in acidic electrolyte, making as-prepared Ru/RuO2-TiO2with better durability at all tested potentials.

3.
Brain Behav Immun ; 117: 1-11, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38141839

RESUMEN

OBJECTIVE: While genetic and cohort studies suggest immune and reduction/oxidation (redox) alterations occur in psychosis, less is known about potential alterations in children and adolescents. METHODS: We conducted a systematic review to identify immune and redox biomarker studies in children and adolescents (mean age ≤ 18 years old) across the psychosis spectrum: from psychotic like experiences, which are common in children, to threshold psychotic disorders like schizophrenia. We conducted meta-analyses when at least three studies measured the same biomarker. RESULTS: The systematic review includes 38 pediatric psychosis studies. The meta-analyses found that youth with threshold psychotic disorders had higher neutrophil/lymphocyte ratio (Hedge's g = 0.40, 95 % CI 0.17 - 0.64), tumor necrosis factor (Hedge's g = 0.38, 95 % CI 0.06 - 0.69), C-reactive protein (Hedge's g = 0.38, 95 % CI 0.05 - 0.70), interleukin-6 (Hedge's g = 0.35; 95 % CI 0.11 - 0.64), and total white blood cell count (Hedge's g = 0.29, 95 % CI 0.12 - 0.46) compared to youth without psychosis. Other immune and oxidative stress meta-analytic findings were very heterogeneous. CONCLUSION: Results from several studies are consistent with the hypothesis that signals often classified as "proinflammatory" are elevated in threshold pediatric psychotic disorders. Data are less clear for immune markers in subthreshold psychosis and redox markers across the subthreshold and threshold psychosis spectrum. Immune and redox biomarker intervention studies are lacking, and research investigating interventions targeting the immune system in threshold pediatric psychosis is especially warranted.


Asunto(s)
Trastornos Psicóticos , Adolescente , Humanos , Niño , Biomarcadores , Proteína C-Reactiva , Interleucina-6 , Estrés Oxidativo
4.
Biomolecules ; 13(11)2023 10 24.
Artículo en Inglés | MEDLINE | ID: mdl-38002251

RESUMEN

Inflammatory bowel disease (IBD) is characterized by chronic relapsing inflammation of the gastrointestinal tract. The prevalence of IBD is increasing with approximately 4.9 million cases reported worldwide. Current therapies are limited due to the severity of side effects and long-term toxicity, therefore, the development of novel IBD treatments is necessitated. Recent findings support apurinic/apyrimidinic endonuclease 1/reduction-oxidation factor 1 (APE1/Ref-1) as a target in many pathological conditions, including inflammatory diseases, where APE1/Ref-1 regulation of crucial transcription factors impacts significant pathways. Thus, a potential target for a novel IBD therapy is the redox activity of the multifunctional protein APE1/Ref-1. This review elaborates on the status of conventional IBD treatments, the role of an APE1/Ref-1 in intestinal inflammation, and the potential of a small molecule inhibitor of APE1/Ref-1 redox activity to modulate inflammation, oxidative stress response, and enteric neuronal damage in IBD.


Asunto(s)
Enfermedades Inflamatorias del Intestino , Estrés Oxidativo , Humanos , Inflamación/tratamiento farmacológico , Inflamación/patología , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Oxidación-Reducción , ADN-(Sitio Apurínico o Apirimidínico) Liasa/metabolismo
5.
Biomaterials ; 303: 122391, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37995457

RESUMEN

Reactive oxygen species (ROS) play a crucial role in regulating the metabolism of tumor growth, metastasis, death and other biological processes. ROS-based nanodynamic therapies (NDTs) are becoming attractive due to non-invasive, low side effects and tumor-specific advantages. NDTs have rapidly developed into numerous branches, such as photodynamic therapy, chemodynamic therapy, sonodynamic therapy and so on. However, the complexity of the tumor microenvironment and the limitations of existing sensitizers have greatly restricted the therapeutic effects of NDTs, which heavily rely on ROS levels. To address the limitations of NDTs, various strategies have been developed to increase ROS yield, which is an urgent aspect for the positive development of NDTs. In this review, the nanodynamic potentiation strategies in terms of unique properties and universalities of NDTs are comprehensively outlined. We mainly summarize the current dilemmas faced by each NDT and the respective solutions. Meanwhile, the NDTs universalities-based potentiation strategies and NDTs-based combined treatments are elaborated. Finally, we conclude with a discussion of the key issues and challenges faced in the development and clinical transformation of NDTs.


Asunto(s)
Neoplasias , Fotoquimioterapia , Humanos , Especies Reactivas de Oxígeno/metabolismo , Medicina de Precisión , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Fotoquimioterapia/métodos , Terapia Combinada , Microambiente Tumoral , Línea Celular Tumoral
6.
Chemistry ; 29(71): e202302369, 2023 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-37721190

RESUMEN

Silicon monoxide (SiO) has attracted great attention due to its high theoretical specific capacity as an alternative material for conventional graphite anode, but its poor electrical conductivity and irreversible side reactions at the SiO/electrolyte interface seriously reduce its cycling stability. Here, to overcome the drawbacks, the dicharged SiO anode coated with Cu coating layer is elaborately designed by in-situ reduction method. Compared with the pristine SiO anode of lithium-ion battery (293 mAh g-1 at 0.5 A g-1 after 200 cycles), the obtained SiO/Cu composite presents superior cycling stability (1206 mAh g-1 at 0.5 A g-1 after 200 cycles). The tight combination of Cu particles and SiO significantly improves the conductivity of the composite, effectively inhibits the side-reaction between the active material and electrolyte. In addition, polypyrrole-coated SiO composites are further prepared by in-situ oxidation method, which delivers a high reversible specific capacity of 1311 mAh g-1 at 0.5 A g-1 after 200 cycles. The in-situ coating strategies in this work provide a new pathway for the development and practical application of high-performance silicon-based anode.

7.
Materials (Basel) ; 16(10)2023 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-37241334

RESUMEN

Oxide-dispersion-strengthened (ODS) alloys have long been considered for high temperature turbine, spacecraft, and nuclear reactor components due to their high temperature strength and radiation resistance. Conventional synthesis approaches of ODS alloys involve ball milling of powders and consolidation. In this work, a process-synergistic approach is used to introduce oxide particles during laser powder bed fusion (LPBF). Chromium (III) oxide (Cr2O3) powders are blended with a cobalt-based alloy, Mar-M 509, and exposed to laser irradiation, resulting in reduction-oxidation reactions involving metal (Ta, Ti, Zr) ions from the metal matrix to form mixed oxides of increased thermodynamic stability. A microstructure analysis indicates the formation of nanoscale spherical mixed oxide particles as well as large agglomerates with internal cracks. Chemical analyses confirm the presence of Ta, Ti, and Zr in agglomerated oxides, but primarily Zr in the nanoscale oxides. Mechanical testing reveals that agglomerate particle cracking is detrimental to tensile ductility compared to the base alloy, suggesting the need for improved processing methods to break up oxide particle clusters and promote their uniform dispersion during laser exposure.

8.
Int J Mol Sci ; 24(7)2023 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-37047024

RESUMEN

Redox is a constant phenomenon in organisms. From the signaling pathway transduction to the oxidative stress during the inflammation and disease process, all are related to reduction-oxidation (redox). Nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor targeting many antioxidant genes. In non-stressed conditions, NRF2 maintains the hemostasis of redox with housekeeping work. It expresses constitutively with basal activity, maintained by Kelch-like-ECH-associated protein 1 (KEAP1)-associated ubiquitination and degradation. When encountering stress, it can be up-regulated by several mechanisms to exert its anti-oxidative ability in diseases or inflammatory processes to protect tissues and organs from further damage. From acute kidney injury to chronic kidney diseases, such as diabetic nephropathy or glomerular disease, many results of studies have suggested that, as a master of regulating redox, NRF2 is a therapeutic option. It was not until the early termination of the clinical phase 3 trial of diabetic nephropathy due to heart failure as an unexpected side effect that we renewed our understanding of NRF2. NRF2 is not just a simple antioxidant capacity but has pleiotropic activities, harmful or helpful, depending on the conditions and backgrounds.


Asunto(s)
Nefropatías Diabéticas , Factor 2 Relacionado con NF-E2 , Humanos , Antioxidantes/uso terapéutico , Antioxidantes/metabolismo , Nefropatías Diabéticas/metabolismo , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Riñón/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Estrés Oxidativo , Especies Reactivas de Oxígeno/metabolismo
9.
Eur J Lipid Sci Technol ; 125(1)2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36818638

RESUMEN

It is desirable to quickly check the composition of lipids in small size samples, but achieving this is challenging using the existing staining methods. Herein, we developed a highly sensitive and semi-quantitative method for analysis of lipid samples with ceric ammonium molybdate (CAM) staining. The CAM detection method was systematically evaluated with a wide range of lipid classes including phospholipids, sphingolipids, glycerolipids, fatty acids (FA) and sterols, demonstrating high sensitivity, stability, and overall efficiency. Additionally, CAM staining provides a clean yellow background in high performance thin-layer chromatography (HPTLC) which facilitates quantification of lipids using image processing software. Lipids can be stained with CAM reagent regardless of their head group types, position of the carbon-carbon double bonds, geometric isomerism and the variation in the length of FA chain, but staining is mostly affected by the degree of unsaturation of the FA backbone. The mechanism of the CAM staining of lipids was proposed on principles of the reduction-oxidation reaction, in which Mo(VI) oxidizes the unsaturated lipids into carbonyl compounds on the HPTLC plate upon heating, while itself being reduced to Mo(IV). This method was applied for the separation, identification, and quantification of lipid extracts from porcine brain.

10.
J Hazard Mater ; 442: 130126, 2023 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-36303354

RESUMEN

Electrochemical treatment can be an effective approach for degrading recalcitrant organic contaminants because its anode/cathode produces powerful oxidizing/reducing conditions. Herein, through the cooperation of the cathodic reductive and anodic oxidative processes, 4-chlorophenol (4-CP) was successfully degraded in an electrochemical system. TiO2 nanotube arrays (TNTAs)/Sb-SnO2 and TNTAs/Pd were successfully prepared and served as the anode and cathode electrodes, respectively, to generate oxidative (hydroxyl radical, ·OH) and reductive (chemically adsorbed hydrogen, Hads) agents. The sequential reduction-oxidation (SRO) process provided a reasonable degradation pathway that accomplished reductive detoxification in the cathode and oxidative mineralization in the anode. The SRO mode achieved dechlorination efficiency (DE) of 86.9 ± 3.9% and TOC removal efficiency of 64.8 ± 4.2% within 3 h and under a current density of 8 mA cm-2, both of which were significantly higher than those obtained in the sequential oxidation-reduction or the simultaneous redox modes. The increment of current density and reaction time could improve 4-CP degradation performance, but a high current density would decrease the cathode stability and a longer reaction time led to the generation of ClO4-. This study has demonstrated that sequential reduction-oxidation can be an effective and tunable process for degrading recalcitrant organic contaminants.

11.
Sci Total Environ ; 862: 160843, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36521603

RESUMEN

Excess chromium (Cr) and arsenic (As) coexist in soil such as chromated copper arsenate (CCA) contaminated sites, leading to high risks of pollution. Fe-biochar with adjustable redox activity offers the possibility of simultaneous stabilization of Cr and As. Here, a series of Fe-biochar with distinct Fe/C structure were rationally produced for the remediation of Cr and As contaminated soil (BCX-Fe, X represented the biomass/Fe ratio). Adsorption tests showed that maximal adsorption of BC5-Fe for Cr(VI) and As(III) reached 73.7 and 81.3 mg/g. A 90-day soil remediation experiment indicated that the introduction of 3% (w/w) Fe-biochar reduced the leaching state of Cr(VI) by 93.8-99.7% and As by 75.2-95.6%. Under simulated groundwater erosion for 10 years and acid rain leaching for 7.5 years, the release levels of Cr(VI) and As in the BC5-Fe remediated soil could meet the groundwater class IV standard in China (Cr(VI)<0.1 mg/L, As<0.05 mg/L). Accelerated aging tests demonstrated that BC5-Fe had long-term Cr and As stabilization ability. The quenching experiment, EPR, and XPS suggested that the corrosion products of Fe dominated the adsorption and redox reactions, while the O groups acted as electron transfer stations and constituted redox microcirculation in the synchronous uptake of Cr/As. Based on these insights, we believe that our study will provide meaningful information about the application potential of Fe-biochar for the heavy metal contaminated soil remediation.


Asunto(s)
Arsénico , Contaminantes del Suelo , Suelo , Carbón Orgánico/química , Cromo/análisis , Contaminantes del Suelo/análisis , Adsorción
12.
Antioxidants (Basel) ; 11(7)2022 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-35883881

RESUMEN

Paeonol is a naturally occurring phenolic agent that attenuates neurotoxicity in neurodegenerative diseases. We aimed to investigate the antioxidant and protective effects of paeonol and determine its transport mechanism in wild-type (WT; NSC-34/hSOD1WT) and mutant-type (MT; NSC-34/hSOD1G93A) motor neuron-like amyotrophic lateral sclerosis (ALS) cell lines. Cytotoxicity induced by glutamate, lipopolysaccharides, and H2O2 reduced viability of cell; however, the addition of paeonol improved cell viability against neurotoxicity. The [3H]paeonol uptake was increased in the presence of H2O2 in both cell lines. Paeonol recovered ALS model cell lines by reducing mitochondrial oxidative stress induced by glutamate. The transport of paeonol was time-, concentration-, and pH-dependent in both NSC-34 cell lines. Kinetic parameters showed two transport sites with altered affinity and capacity in the MT cell line compared to the WT cell line. [3H]Paeonol uptake increased in the MT cell line transfected with organic anion transporter1 (Oat1)/Slc22a6 small interfering RNA compared to that in the control. Plasma membrane monoamine transporter (Pmat) was also involved in the uptake of paeonol by ALS model cell lines. Overall, paeonol exhibits neuroprotective activity via a carrier-mediated transport system and may be a beneficial therapy for preventing motor neuronal damage under ALS-like conditions.

13.
Cell Rep ; 40(2): 111065, 2022 07 12.
Artículo en Inglés | MEDLINE | ID: mdl-35830797

RESUMEN

Tissue-resident macrophages (TRMs) are heterogeneous cell populations found throughout the body. Depending on their location, they perform diverse functions maintaining tissue homeostasis and providing immune surveillance. To survive and function within, TRMs adapt metabolically to the distinct microenvironments. However, little is known about the metabolic signatures of TRMs. The thymus provides a nurturing milieu for developing thymocytes yet efficiently removes those that fail the selection, relying on the resident thymic macrophages (TMφs). This study harnesses multiomics analyses to characterize TMφs and unveils their metabolic features. We find that the pentose phosphate pathway (PPP) is preferentially activated in TMφs, responding to the reduction-oxidation demands associated with the efferocytosis of dying thymocytes. The blockade of PPP in Mφs leads to decreased efferocytosis, which can be rescued by reactive oxygen species (ROS) scavengers. Our study reveals the key role of the PPP in TMφs and underscores the importance of metabolic adaptation in supporting Mφ efferocytosis.


Asunto(s)
Macrófagos , Vía de Pentosa Fosfato , Macrófagos/metabolismo , Fagocitosis , Especies Reactivas de Oxígeno/metabolismo
14.
Curr Drug Targets ; 23(13): 1261-1276, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35792117

RESUMEN

Lung toxicity is a key limiting factor for cancer therapy, especially lung, breast, and esophageal malignancies. Radiotherapy for chest and breast malignancies can cause lung injury. However, systemic cancer therapy with chemotherapy may also induce lung pneumonitis and fibrosis. Radiotherapy produces reactive oxygen species (ROS) directly via interacting with water molecules within cells. However, radiation and other therapy modalities may induce the endogenous generation of ROS and nitric oxide (NO) by immune cells and some nonimmune cells such as fibroblasts and endothelial cells. There are several ROS generating enzymes within lung tissue. NADPH Oxidase enzymes, cyclooxygenase-2 (COX-2), dual oxidases (DUOX1 and DUOX2), and the cellular respiratory system in the mitochondria are the main sources of ROS production following exposure of the lung to anticancer agents. Furthermore, inducible nitric oxide synthase (iNOS) has a key role in the generation of NO following radiotherapy or chemotherapy. Continuous generation of ROS and NO by endothelial cells, fibroblasts, macrophages, and lymphocytes causes apoptosis, necrosis, and senescence, which lead to the release of inflammatory and pro-fibrosis cytokines. This review discusses the cellular and molecular mechanisms of redox-induced lung injury following cancer therapy and proposes some targets and perspectives to alleviate lung toxicity.


Asunto(s)
Lesión Pulmonar , Neoplasias , Traumatismos por Radiación , Humanos , Especies Reactivas de Oxígeno , Células Endoteliales , Oxidación-Reducción , Óxido Nítrico , Pulmón , Fibrosis
15.
J Hazard Mater ; 430: 128479, 2022 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-35739664

RESUMEN

Electroactive Fe-biochar has attracted significant attention for As(III)/Cr(VI) immobilization through redox reactions, and its performance essentially lies in the regulation of various Fe/C moieties for desired redox performance. Here, a series of Fe-biochar with distinct Fe/C speciation were rationally produced via two-step pyrolysis of iron minerals and biomass waste at 400-850 °C (BCX-Fe-Y, X and Y represented the first- and second-step pyrolysis temperature, respectively). The redox transformation of Cr(VI) and As(III) by Fe-biochar was evaluated in simulated wastewater under oxic or anoxic conditions. Results showed that more effective Cr(VI) reduction could be achieved by BCX-Fe-400, while a higher amount of As (III) was oxidized by BCX-Fe-850 under the anoxic environment. Besides, BCX-Fe-400 could generate more reactive oxygen species (e.g.,•OH) by reducing the O2, which enhanced the redox-related transformation of pollutants under the oxic situation. The evolving redox performance of Fe-biochar was governed by the transition of the redox state from reductive to oxidative related to the Fe/C speciation. The small-sized amorphous/low-crystalline ferrous minerals contributed to a higher electron-donating capacity (0.43-1.28 mmol g-1) of BCX-Fe-400. In contrast, the oxidative surface oxygen-functionalities (i.e., carboxyl and quinoid) on BCX-Fe-850 endowed a stronger electron-accepting capacity (0.71-1.39 mmol g-1). Moreover, the graphitic crystallites with edge-type defects and porous structure facilitated the electron transfer, leading to a higher electron efficiency of BCX-Fe-850. Overall, we unveiled the roles of both Fe and C speciation in maneuvering the redox reactivity of Fe-biochar, which can advance our rational design of electroactive Fe-biochar for redox-related environmental remediation.


Asunto(s)
Arsénico , Cromo , Carbono , Carbón Orgánico/química , Cromo/química , Hierro/química , Minerales , Oxidación-Reducción
16.
Materials (Basel) ; 15(10)2022 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-35629722

RESUMEN

One of the possible solutions for the transition of the actual energetic model is the use of thermal energy storage technologies. Among them, thermochemical energy storage based on redox reactions involving metal oxides is very promising due to its high energy density. This paper deals with the development of the kinetic study based on data extracted from the thermogravimetric analysis of a cobalt-nickel mixed oxide (Co2.4Ni0.6O4) without and with the addition of SiO2 particles to improve the cyclability. The results show that in the reduction reaction the activation energy is not affected by the addition of SiO2 particles while in the oxidation reaction an increase in the activation energy is observed. The theoretical models fitting with the experimental data are different for each material in the reduction reaction. The mixed oxide is controlled by a nucleation and growth mechanism for conversion ratios higher than 0.5, while the added material is controlled by diffusion mechanisms. In the oxidation reaction, the two materials are controlled by a nucleation and growth mechanism for conversion ratios higher than 0.5.

17.
Microorganisms ; 10(5)2022 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-35630497

RESUMEN

The zam gene mediating resistance to acetazolamide in cyanobacteria was discovered thirty years ago during a drug tolerance screen. We use phylogenetics to show that Zam proteins are distributed across cyanobacteria and that they form their own unique clade of the ribonuclease II/R (RNB) family. Despite being RNB family members, multiple sequence alignments reveal that Zam proteins lack conservation and exhibit extreme degeneracy in the canonical active site-raising questions about their cellular function(s). Several known phenotypes arise from the deletion of zam, including drug resistance, slower growth, and altered pigmentation. Using room-temperature and low-temperature fluorescence and absorption spectroscopy, we show that deletion of zam results in decreased phycocyanin synthesis rates, altered PSI:PSII ratios, and an increase in coupling between the phycobilisome and PSII. Conserved cysteines within Zam are identified and assayed for function using in vitro and in vivo methods. We show that these cysteines are essential for Zam function, with mutation of either residue to serine causing phenotypes identical to the deletion of Zam. Redox regulation of Zam activity based on the reversible oxidation-reduction of a disulfide bond involving these cysteine residues could provide a mechanism to integrate the 'central dogma' with photosynthesis in cyanobacteria.

18.
Water Res ; 218: 118453, 2022 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-35489147

RESUMEN

Chloronitrobenzenes (CNBs) are typical refractory aromatic pollutants. The reduction products of CNBs often possess higher toxicity, and the electron-withdrawing substituent groups are detrimental to the ring-opening during the oxidation treatment, leading to ineffective removal of CNBs by either reduction or oxidation technology. Herein we demonstrate a controllable reduction-oxidation coupling (ROC) process composed of zero-valent iron (ZVI) and H2O2 for the effective removal of CNBs from both water and soil. In water, ZVI first reduced p-CNB into 4-chloronitrosobenzene and 4-chloroaniline intermediates, which were then suffered from the subsequent oxidative ring-opening by ·OH generated from the reaction between Fe(II) and H2O2. By controlling the addition time of H2O2, the final mineralization rate of p-CNB reached 6.6 × 10-1 h-1, about 74 times that of oxidation alone (9.0 × 10-3 h-1). More importantly, this controllable ROC process was also applicable for the site remediation of CNBs contaminated soil by either ex-situ treatment or in-situ injection, and, respectively decreased the concentrations of p-CNB, m-CNB, and o-CNB from 1105, 980, and 94 mg/kg to 3, 1, and < 1mg/kg, meeting the remediation goals (p-CNB: < 32.35 mg/kg, o-CNB and m-CNB: < 1.98 mg/kg). These laboratory and field trial results reveal that this controllable ROC strategy is very promising for the treatment of electron-withdrawing groups substituted aromatic contaminates.


Asunto(s)
Restauración y Remediación Ambiental , Contaminantes Químicos del Agua , Peróxido de Hidrógeno , Hierro , Nitrobencenos , Oxidación-Reducción , Suelo , Agua , Contaminantes Químicos del Agua/análisis
19.
Materials (Basel) ; 15(6)2022 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-35329472

RESUMEN

A sol-gel technique was applied to prepare the two-component oxide system Cu-Mg-O, where MgO plays the role of oxide matrix, and CuO is an active chemical looping component. The prepared samples were characterized by scanning electron microscopy, low-temperature nitrogen adsorption, and X-ray diffraction analysis. The reduction behavior of the Cu-Mg-O system was examined in nine consecutive reduction/oxidation cycles. The presence of the MgO matrix was shown to affect the ability of CuO towards reduction and re-oxidation significantly. During the first reduction/oxidation cycle, the main characteristics of the oxide system (particle size, crystallization degree, etc.) undergo noticeable changes. Starting from the third cycle, the system exhibits a stable operation, providing the uptake of similar hydrogen amounts within the same temperature range. Based on the obtained results, the two-component Cu-Mg-O system can be considered as a prospective chemical looping agent.

20.
Mater Today Bio ; 14: 100223, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35243298

RESUMEN

Inflammatory arthritis is a major cause of disability in the elderly. This condition causes joint pain, loss of function, and deterioration of quality of life, mainly due to osteoarthritis (OA) and rheumatoid arthritis (RA). Currently, available treatment options for inflammatory arthritis include anti-inflammatory medications administered via oral, topical, or intra-articular routes, surgery, and physical rehabilitation. Novel alternative approaches to managing inflammatory arthritis, so far, remain the grand challenge owing to catastrophic financial burden and insignificant therapeutic benefit. In the view of non-targeted systemic cytotoxicity and limited bioavailability of drug therapies, a major concern is to establish stimuli-responsive drug delivery systems using nanomaterials with on-off switching potential for biomedical applications. This review summarizes the advanced applications of triggerable nanomaterials dependent on various internal stimuli (including reduction-oxidation (redox), pH, and enzymes) and external stimuli (including temperature, ultrasound (US), magnetic, photo, voltage, and mechanical friction). The review also explores the progress and challenges with the use of stimuli-responsive nanomaterials to manage inflammatory arthritis based on pathological changes, including cartilage degeneration, synovitis, and subchondral bone destruction. Exposure to appropriate stimuli induced by such histopathological alterations can trigger the release of therapeutic medications, imperative in the joint-targeted treatment of inflammatory arthritis.

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