Sustainable remediation of Cr(VI)-contaminated soil by soil washing and subsequent recovery of washing agents using biochar supported nanoscale zero-valent iron

Soil contamination by Cr(VI) has attracted widespread attention globally in recent years, but it remains a significant challenge in developing an environmentally friendly and eco-sustainable technique for the disposal of Cr(VI)-contaminated soil. Herein, a sustainable cyclic soil washing system for Cr(VI)-polluted soil remediation and the recovery of washing agents using biochar supported nanoscale zero-valent iron (nZVI-BC) was established. Citric acid (CA) was initially screened to desorb Cr(VI) from contaminated soil, mobilizing Cr from the highly bioaccessible fractions. The nZVI-BC exhibited superior properties for Cr(VI) and Cr(total) removal from spent effluent, allowing effective recovery of the washing agents. The elimination mechanism of Cr(total) by nZVI-BC involved the coordinated actions of electrostatic adsorption, reduction, and co-precipitation. The contributions to Cr(VI) reduction by Fe0, surface-bound Fe(II), and soluble Fe(II) were 0.6 %, 39.8 %, and 59.6 %, respectively. Meanwhile, CA favored the activity of surface-bound Fe(II) and Fe0 in nZVI-BC, enhancing the production of soluble Fe(II) to strengthen Cr(VI) removal. Finally, the recovered washing agent was proven to be reused three times. This study showcases that the combined soil washing using biodegradable chelant CA and effluent treatment by nZVI-BC could be a sustainable and promising strategy for Cr(VI)-contaminated soil remediation.

[The identification of a novel reassortant H3N2 avian influenza virus based on nanopore sequencing technology and genetic characterization]

Objective: To identify a novel reassortant H3N2 avian influenza virus using nanopore sequencing technology and analyze its genetic characteristics. Methods: The positive samples of the H3N2 avian influenza virus, collected from the external environment in the farmers' market of Guangzhou, were cultured in chicken embryos. The whole genome was sequenced by targeted amplification and nanopore sequencing technology. The genetic characteristics were analyzed using bioinformatics software. Results: The phylogenetic trees showed that each gene fragment of the strain belonged to the Eurasian evolutionary branch, and the host source was of avian origin. The HA gene was closely related to the origin of the H3N6 virus. The NA gene was closely related to the H3N2 avian influenza virus from 2017 to 2020. The PB1 gene was closely related to the H5N6 avian influenza virus in Guangxi Zhuang Autonomous Region and Fujian Province from 2016 to 2022 and was not related to the PB1 gene of the H5N6 avian influenza epidemic strain in Guangzhou. The other internal gene fragments had complex sources with significant genetic diversity. Molecular characteristics indicated that the strain exhibited the molecular characteristics of a typical low pathogenic avian influenza virus and tended to bind to the receptors of avian origin. On important protein sites related to biological characteristics, this strain had mutations of PB2-L89V, PB1-L473V, NP-A184K, M1-N30D/T215A, and NS1-P42S/N205S. Conclusions: This study identified a novel reassortant H3N2 avian influenza virus by nanopore sequencing, with the PB1 gene derived from the H5N6 avian influenza virus. The virus had a low ability to spread across species, but further exploration was needed to determine whether its pathogenicity to the host was affected.

UiO-66/AgNPs Coating for Dental Implants in Preventing Bacterial Infections

Titanium (Ti)-based biomaterials lack inherent antimicrobial activities, and the dental plaque formed on the implant surface is one of the main risk factors for implant infections. Construction of an antibacterial surface can effectively prevent implant infections and enhance implant success. Silver nanoparticles (AgNPs) exhibit broad antibacterial activity and a low tendency to induce drug resistance, but AgNPs easily self-aggregate in the aqueous environment, which significantly impairs their antibacterial activity. In this study, UiO-66/AgNP (U/A) nanocomposite was prepared, where zirconium metal-organic frameworks (UiO-66) were employed as the confinement matrix to control the particle size and prevent aggregation of AgNPs. The bactericidal activity of U/A against methicillin-resistant Staphylococcus aureus and Escherichia coli increased nearly 75.51 and 484.50 times compared with individually synthesized Ag. The antibacterial mechanism can be attributed to the enhanced membrane rupture caused by the ultrafine AgNPs on UiO-66, leading to protein leakage and generation of intracellular reactive oxygen species. Then, U/A was loaded onto Ti substrates (Ti-U/A) by using self-assembly deposition methods to construct an antibacterial surface coating. Ti-U/A exhibited excellent antibacterial activities and desired biocompatibility both in vitro and in vivo. The U/A nanocomposite coating technique is thus expected to be used as a promising surface modification strategy for Ti-based dental implants for preventing dental implant infections.

18F-Labeled Amidobenzimidazole Analogue for Visualizing STING Expression in Tumor

The stimulator of interferon genes (STING) is pivotal in mediating STING-dependent type I interferon production, which is crucial for enhancing tumor rejection. Visualizing STING within the tumor microenvironment is valuable for STING-related treatments, yet the availability of suitable STING imaging probes is limited. In this study, we developed [18F]AlF-ABI, a novel 18F-labeled agent featuring an amidobenzimidazole core structure, for positron emission tomography (PET) imaging of STING in B16F10 and CT26 tumors. [18F]AlF-ABI was synthesized with a decay-corrected radiochemical yield of 38.0 ± 7.9% and radiochemical purity exceeding 97%. The probe exhibited a nanomolar STING binding affinity (KD = 35.6 nM). Upon administration, [18F]AlF-ABI rapidly accumulated at tumor sites, demonstrating significantly higher uptake in B16F10 tumors compared to CT26 tumors, consistent with STING immunofluorescence patterns. Specificity was further validated through in vitro cell experiments and in vivo blocking PET imaging. These findings suggest that [18F]AlF-ABI holds promise as an effective agent for visualizing STING in the tumor microenvironment.

Chalcopyrite functionalized ceramic membrane for micropollutants removal and membrane fouling control via peroxymonosulfate activation: The synergy of nanoconfinement effect and interface interaction

This work developed a novel chalcopyrite (CuFeS2) incorporated catalytic ceramic membrane (CFSCM), and comprehensively evaluated the oxidation-filtration efficiency and mechanism of CFSCM/peroxymonosulfate (PMS) for organics removal and membrane fouling mitigation. Results showed that PMS activation was more efficient in the confined membrane pore structure. The CFSCM50/PMS filtration achieved almost complete removal of 4-Hydroxybenzoic acid (4-HBA) under the following conditions: pH = 6.0, CPMS = 0.5 mM, and C4-HBA = 10 mg/L. Meanwhile, the membrane showed good stability after multiple uses. During the reaction, SO4•- and •OH were generated in the CFSCM50/PMS system, and SO4•- was considered to be the dominant reactive species for pollutant removal. The roles of copper, iron, and sulfur species, as well as the possible catalytic mechanism were also clarified. Besides, the CFSCM50/PMS catalytic filtration exhibited excellent antifouling properties against NOM with reduced reversible and irreversible fouling resistances. The Extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory analysis showed an increased in repulsive energy at the membrane-foulant interface in the CFSCM50/PMS system. Membrane fouling model analysis indicated that standard blocking was the dominant fouling pattern for CFSCM50/PMS filtration. Overall, this work demonstrates an efficient catalytic filtration process for foulants removal and outlines the synergy of catalytic oxidation and interface interaction.

Effective remediation of leachate concentrate by peroxymonosulfate in a catalytic ceramic membrane filtration process: Performance and mechanism

Membrane concentrated landfill leachate has been characterized by complex component and degradation resistant. In this work, a new catalytic ceramic membrane (CuCM) was developed by in-situ integrating copper oxide in the membrane and used in combination with peroxymonosulfate (PMS) for leachate concentrate treatment. The performance and key factors of the CuCM/PMS system were systematically studied. Results showed that the CuCM/PMS system experienced promising efficiency in the pH range of 3 ∼ 11. The highest COD, TOC, UV254 and Color removal efficiency achieved by the CuCM-3/PMS system under the conditions of pH = 7.0 and CPMS = 10 mM, which reached up to 63.4%, 50.5%, 75.1% and 90.2%, respectively. The possible mechanism of leachate remediation was proposed and non-free radicals (Cu(Ⅲ), 1O2) played an important role in the CuCM/PMS system for leachate remediation. The fluorescence spectrum and GC-MS analysis showed that the refractory organics with a high molecular weight in the leachate concentrate were mostly oxidized into small molecules, which also alleviated the membrane fouling. In addition, the slight decrease in COD (7.4%) and TOC (9.7%) after 6 cycles revealed the good catalytic stability and reusability of CuCM-3/PMS. This work provides a feasible strategy for leachate concentrate remediation via a nonradical oxidation process.

Immune-mediated hematological disease in dogs is associated with alterations of the fecal microbiota: a pilot study

BACKGROUND

The dog is the most popular companion animal and is a valuable large animal model for several human diseases. Canine immune-mediated hematological diseases, including immune-mediated hemolytic anemia (IMHA) and immune thrombocytopenia (ITP), share many features in common with autoimmune hematological diseases of humans. The gut microbiome has been linked to systemic illness, but few studies have evaluated its association with immune-mediated hematological disease. To address this knowledge gap, 16S rRNA gene sequencing was used to profile the fecal microbiota of dogs with spontaneous IMHA and ITP at presentation and following successful treatment. In total, 21 affected and 13 healthy control dogs were included in the study.

RESULTS

IMHA/ITP is associated with remodeling of fecal microbiota, marked by decreased relative abundance of the spirochete Treponema spp., increased relative abundance of the pathobionts Clostridium septicum and Escherichia coli, and increased overall microbial diversity. Logistic regression analysis demonstrated that Treponema spp. were associated with decreased risk of IMHA/ITP (odds ratio [OR] 0.24-0.34), while Ruminococcaceae UCG-009 and Christensenellaceae R-7 group were associated with increased risk of disease (OR = 6.84 [95% CI 2-32.74] and 8.36 [95% CI 1.85-71.88] respectively).

CONCLUSIONS

This study demonstrates an association of immune-mediated hematological diseases in dogs with fecal dysbiosis, and points to specific bacterial genera as biomarkers of disease. Microbes identified as positive or negative risk factors for IMHA/ITP represent an area for future research as potential targets for new diagnostic assays and/or therapeutic applications.

Enhancement of peroxymonosulfate activation by humic acid-modified sludge biochar: Role of singlet oxygen and electron transfer pathway

Sludge biochar (SBC) modified by humic acid (HA) was used to activate peroxymonosulfate (PMS) for degrading naproxen (NPX). HA-modified biochar (SBC-50HA) boosted the catalytic performance of SBC for PMS activation. The SBC-50HA/PMS system had good reusability and structural stability, and was unaffected by complex water bodies. The results of Fourier transform infrared (FTIR) and X-ray diffraction spectroscopy (XPS) indicated that graphitic carbon (CC), graphitic N, and C-O on SBC-50HA played a vital part on the removal of NPX. The key role of non-radical pathways such as singlet oxygen (¹O₂) and electron transfer in the SBC-50HA/PMS/NPX system was verified by inhibition experiments, electron paramagnetic resonance (EPR), electrochemistry, and PMS consumption. The possible degradation pathway of NPX was proposed by density functional theory (DFT) calculations, and the toxicity of NPX and its degradation intermediates were evaluated.

Preparation, performance and mechanism of metal oxide modified catalytic ceramic membranes for wastewater treatment

Catalytic ceramic membranes (CMs) integrated with different metal oxides were designed and fabricated by an impregnation-sintering method. The characterization results indicated that the metal oxides (Co₃O₄, MnO₂, Fe₂O₃ and CuO) were uniformly anchored around the Al₂O₃ particles of the membrane basal materials, which could provide a large number of active sites throughout the membrane for the activation of peroxymonosulfate (PMS). The performance of the CMs/PMS system was evaluated by filtrating a phenol solution under different operating conditions. All the four catalytic CMs showed desirable phenol removal efficiency and the performance was in order of CoCM, MnCM, FeCM and CuCM. Moreover, the low metal ion leaching and high catalytic activity even after the 6th run revealed the good stability and reusability of the catalytic CMs. Quenching experiments and electron paramagnetic resonance (EPR) measurements were conducted to discuss the mechanism of PMS activation in the CMs/PMS system. The reactive oxygen species (ROS) were supposed to be SO₄˙^- and ¹O₂ in the CoCM/PMS system, ¹O₂ and O₂˙^- in the MnCM/PMS system, SO₄˙^- and ·OH in the FeCM/PMS system, and SO₄˙^- in the CuCM/PMS system, respectively. The comparative study on the performance and mechanism of the four CMs provides a better understanding of the integrated PMS-CMs behaviors.

Efficient degradation of Congo red by persulfate activated with different particle sizes of zero-valent copper: performance and mechanism

In this study, Congo red (CR) was degraded by different particle sizes of zero-valent copper (ZVC) activated persulfate (PS) under mild temperature. The CR removal by 50 nm, 500 nm, 15 μm of ZVC activated PS was 97%, 72%, and 16%, respectively. The co-existence of SO₄^2- and Cl^- promoted the degradation of CR, and HCO₃^- and H₂PO₄^- were detrimental to the degradation. With the reduction of ZVC particle size, the effect of coexisting anions on degradation grew stronger. The high degradation efficiency of 50 nm and 500 nm ZVC was achieved at pH=7.0, while the high degradation of 15 μm ZVC was achieved at pH=3.0. It was more favorable to leach copper ions for activating PS to generate reactive oxygen species (ROS) with the smaller particle size of ZVC. The radical quenching experiment and electron paramagnetic resonance (EPR) analysis indicated that SO₄^-•, •OH and •O₂^- existed in the reaction. The mineralization of CR reached 80% and three possible paths were suggested for the degradation. Moreover, the degradation of 50 nm ZVC can still reach 96% in the 5th cycle, indicating promising application potential in dyeing wastewater treatment.

Ultrafast short-range catalytic pathway modified peroxymonosulfate activation over CuO with surface oxygen defects for tetracycline hydrochloride degradation

The presence of antibiotics in water bodies seriously threatens the ecosystem and human health. Advanced oxidation processes (AOPs) based on peroxymonosulfate (PMS), an effective method to remove antibiotics, have a bottleneck problem that the low oxidant utilization is attributed to the hindered electron transfer between metal oxides and peroxides. Here, CuO with rich oxygen vacancies (OVs), MSCuO-300, was synthesized to efficiently degrade tetracycline hydrochloride (TTCH) (k = 0.095 min^-1). The dominant role of direct adsorption and activation of OVs and its regulated Cu-O, rather than surface hydroxyl adsorption, mediated a short-range catalytic pathway. The shortened catalytic pathway between active sites and PMS accelerated the charge transfer at the interface, which promoted PMS activation. Compared with Cu_xO-500 and Commercial CuO, the activation rate of PMS was increased by 11.97, and 12.64 times, respectively. OVs contributed to the production of ¹O₂ and O₂^•-, the main active species. In addition, MSCuO-300/PMS showed excellent adaptability to real water parameters, such as pH (3-11), anions, and continuous reactor maintained for 168 h. This study provides a successful case for the purification of antibiotic-containing wastewater in the design of efficient catalysts by oxygen defect strategies.

Facilitated catalytic ozonation of atrazine over highly stabilized Zn-Al layered double oxides composites: efficacy and mechanism

A series of Zn-Al Layered Double Oxides (ZnAl-LDO) composites were prepared by the hydrothermal and calcination method via employing the Zn-Al Layered Double Hydroxide (ZnAl-LDH) as the precursors in the present study. The structural properties and the catalytic ozonation activity of Zn_rAl-T composites synthesized with different Zn/Al molar ratios and calcination temperatures were systematically investigated. Diversified characterizations were applied to analyze the phase structure and chemical composition of Zn_rAl-T composites. As the calcination temperature increased, the layered ZnAl-LDH structure could be entirely destroyed and the crystallinity gradually improved. With the Zn/Al mole ratio of 4.0 and calcination temperature of 500°C, the Zn4Al-500 composite obtained the outstanding catalytic ozonation performance for atrazine (ATZ) degradation with the pseudo-first-order constant of 0.5080 min^-1, which was 5 times more than that in O₃ alone. Meanwhile, the ATZ degradation efficiency was gradually enhanced from 44.1% to 99.9% within 3.0 min when the solution pH ranged from 3.0 to 10.0. Besides, the Zn₄Al-500 composite exhibited splendid stability over multiple reaction cycles. In addition, the radical scavenging test and electron spin resonance measurement demonstrated that superoxide radical and hydroxyl radical are the dominant reactive species in O₃/Zn₄Al-500 process. Moreover, nineteen and ten transformation products were detected in O₃ alone and O₃/Zn₄Al-500 process, and possible degradation pathways of ATZ were further elucidated. Overall, the Zn₄Al-500 composite would provide a potential alternative for pollutants removal due to its high catalytic ozonation efficiency, stability, and reusability.

Coagulation characteristic and mechanism of Fe(III) salts toward typical Cr(III) complexes in wastewater treatment

Cr(III) complexes are typical pollutants in various industrial wastewater and pose a serious threat to the ecosystem and humans. The coagulation process is commonly used in water treatment plants, yet its removal characteristic and mechanism toward Cr(III) complexes have been rarely reported. In this study, the Fe(III) coagulation process was adopted for the evaluation of Cr(III) complex removal in terms of Cr residual concentration as well as floc size. The results showed that Fe(III) with a dose of 0.8 mM removed more than 80% of total Cr for Cr³⁺ and Cr(III)-acetate, whereas poor removal rate (~ 50%) was obtained for Cr(III)-citrate under the same conditions. Neutral and alkaline conditions facilitated Cr(III)-acetate removal by Fe(III) coagulation, while limited influence was observed for Cr(III)-citrate with various pH. The main removal mechanism of Cr(III)-acetate was precipitation. Cr(III)-citrate elimination largely relied on the adsorption property and sweeping effect of Fe floc. Moreover, Cr(III)-acetate was easier to be separated from a solution since the generated floc sizes were 270 μm. Flocs that formed in the Cr(III)-citrate treatment were only 0.3 μm, resulting in separation difficulties during the coagulation process. The presence of Cr(III)-acetate and Cr(III)-citrate caused a significant decline in membrane flux. This study provided fundamental knowledge of Fe coagulation treatment in Cr(III) complex-containing wastewater.

Revealing the synergistic mechanism of the generation, migration and nearby utilization of reactive oxygen species in FeOCl-MOF yolk-shell reactors

Fenton-like reactions is attractive for environmental pollutant control, but there is an urgent need to improve the utilisation of hydroxyl radicals (·OH) in practical applications. Here, for the first time, FeOCl is encapsulated within a Metal Organic Framework (MOF) (Materials of Institut Lavoisier-101 (MIL-101(Fe))) as a yolk-shell reactor (FeOCl-MOF) by in situ growth. The interaction between FeOCl and the MOF not only increases the electron density of FeOCl, but also shifts down the d-band centre. The increase of electron density could promote the efficient conversion of H₂O₂ to ·OH catalysed by FeOCl. And the shift of the d-band centre to the lower energy level facilitates the desorption of ·OH. Experimental and theoretical calculations showed that the high catalytic performance was attributed to the unique yolk-shell structure that concentrates the catalytic and adsorption sites in a confinement space, as well as the improved electron density and d-band centre for efficient generation, rapid desorption and utilized nearby of ·OH. Which is utilized nearby by the organic pollutants adsorbed by the surface MOF, thus greatly improving the effective conversion of H₂O₂ and the ·OH utilisation (from 25.5% (Fe²⁺/H₂O₂) to 77.1% (FeOCl-MOF/H₂O₂)). In addition, a catalytic reactor was constructed to achieve continuous efficient treatment of organic pollutants. This work provides a Fenton-like microreactor for efficient generation, rapid desorption, and nearby utilization of ·OH to improve future technologies for deep water purification in complex environments.

Ultrastable Fe-N-C Fuel Cell Electrocatalysts by Eliminating Non-Coordinating Nitrogen and Regulating Coordination Structures at High Temperatures

Pyrolyzed Fe-N-C materials have attracted considerable interest as one of the most active noble-metal-free electrocatalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). Despite significant progress is made in improving their catalytic activity during past decades, the Fe-N-C catalysts still suffer from fairly poor electrochemical and storage stability, which greatly hurdles their practical application. Here, an effective strategy is developed to greatly improve their catalytic stability in PEMFCs and storage stability by virtue of previously unexplored high-temperature synthetic chemistry between 1100 and 1200 °C. Pyrolysis at this rarely adopted temperature range not only enables the elimination of less active nitrogen-doped carbon sites that generate detrimental peroxide byproduct but also regulates the coordination structure of Fe-N-C from less stable D1 (O-FeN₄ C₁₂ ) to a more stable D2 structure (FeN₄ C₁₀ ). The optimized Fe-N-C catalyst exhibits excellent stability in PEMFCs (>80% performance retention after 30 h under H₂ /O₂ condition) and no activity loss after 35 day storage while maintaining a competitive ORR activity and PEMFC performance.

The efficient adsorption of tetracycline from aqueous solutions onto polymers with different N-vinylpyrrolidone contents: equilibrium, kinetic and dynamic adsorption

Extensive use of antibiotics in the world will cause potential risks to human health and ecosystems. The removal of these antibiotics has attracted much attention. Composite materials are growing attention for diverse pollutants separation and removal based on their specific functionality and surface area. In this study, a series of N-vinylpyrrolidone-divinylbenzene polymers (NVPD) with different N-vinylpyrrolidone (NVP) contents were facilely prepared for the adsorption of tetracycline (TC). The effect of polymer surface properties and aqueous solution chemistry (pH, ionic strength, humic acid) on TC adsorption was further studied. The dynamic adsorption and regeneration experiments were also assessed. The results showed that only 25% of NVP was involved in the reaction. When NVP dosage (%) was 75%, polymer (NVPD-g) owned the largest BET surface area (613.23 m2/g) and obtained the maximum TC adsorption capacities (258.76 mg/g). In the kinetic, the adsorption between TC and polymers with NVP was controlled by chemical adsorption and intra-particle diffusion. The TC adsorption process of NVPD-g depended on the contribution of the hydrophobic effect, electrostatic interactions, H-bonding, π-π electron donor-acceptor (EDA) interactions, and cation-π bonding. Moreover, the removal efficiency of TC by NVPD-g was enhanced in the presence of humic acid (HA) in the dynamic adsorption and 1197 BV (2394 mL) of TC simulated wastewater can be treated. These findings suggest that NVPD-g has a potential application in the purification of TC.

Fe-O-Zr in MOF for effective photo-Fenton Bisphenol A degradation: Boosting mechanism of electronic transmission

To enhance the efficiency of photogenerated electron transport in the photo-Fenton reaction, we report a Fe-doped UiO-66 containing Fe-O-Zr bonds for the photo-Fenton reaction system. The modulation changes the energy bandgap from 3.89 eV to 2.02 eV, and its absorption edge is red-shifted from the UV region to the visible range. Simultaneously, Fe-O-Zr reduces the redox internal resistance, enhances the photocurrent and catalytic process, and suppresses the compounding of photogenerated electrons and holes. These promote the valence cycling of Fe(III)/Fe(II) in the photo-Fenton reaction. Compared with UiO-66, the hydroxyl radical generation efficiency of this reaction system was increased by 5.8 times (UiO-66: 0.0009 mM/min, FeUiO-1: 0.0053 mM/min). The degradation efficiency of BPA was increased by 100.8 times (UiO-66: 0.0012 min^-1, FeUiO-1: 0.121 min^-1), and the removal rate of TOC also reached 69.55%. The removal rate of BPA was maintained at more than 85% through 5 cycles. The reaction system was able to maintain a removal rate more than 97% at pH:3-9. In the presence of anions, such as Cl^-, SO₄^2-, NO₃^2- (10 mM), the degradation rates of BPA were still above 94%. The catalytic efficiency was 2.02 times higher under natural light than relative to dark conditions. It was demonstrated by EPR and inhibition experiments that the main active species in the reaction were hydroxyl radicals and vacancies. The HOMO energy level and LUMO energy level of the intermediates were analyzed, and the possible degradation pathways of the active species were speculated. Evaluation of the biological toxicity of intermediates demonstrated that the system can effectively detoxify BPA. This investigation provides a reference method to enhance the efficiency of the photo-Fenton reaction of MOFs.

Combining international survey datasets to identify indicators of stress during the COVID-19 pandemic: A machine learning approach to improve generalization

Introduction

The magnitude and exceptional opportunity to research the psychological distress of shelter in place resulted in a publication frenzy on a smorgasbord of research studies of variable scientific robustness. Confinement, fear of contagion, social isolation, financial hardship, etc. equated to stratospheric stress levels. The decline in protective factors as a function of quarantine anecdotally reflected historic rates of anxiety and depression.

Objectives

In this study, we combined 12 variegate datasets and developed an algorithm to build a model to identify key predictors of pandemic-related stress with high accuracy and generalizability.

Methods

This study reports on existing published data. We first describe the International (Adamson et al., 2020) and then the Italian dataset (Flesia et al., 2020). The time-frame (first wave of lockdown), method (survey), measurement tool (Perceived Stress Scale), and outcome measures were extremely similar to enable consolidation of datasets (see Figure1). The Flesia et al., (2020) data set was integrated into the Adamson et al., (2020) dataset as the first step towards data validation construction of the ML predictive model.

Results

We aim to demonstrate the strength of combining cross-cultural datasets, and the applicability of ML algorithms to facilitate the process and generate a predictive model that identifies and validates key predictors of pandemic-related stress and accommodates for interaction with demographic, cultural, and other mitigating factors while concurrently having high generalizability.

Conclusions

We believe our model provides clinicians, researchers, and decision-makers with evidence to investigate the moderators and mediators of stress, and introduce novel interventions to mitigate the long-term effects of the COVID-19 pandemic.

Disclosure

No significant relationships.

Evidence of altered fatty acid metabolism in dogs with naturally occurring valvular heart disease and congestive heart failure

INTRODUCTION

Myxomatous mitral valve disease (MMVD) is the most common cardiac condition in adult dogs. The disease progresses over several years and affected dogs may develop congestive heart failure (HF). Research has shown that myocardial metabolism is altered in cardiac disease, leading to a reduction in β-oxidation of fatty acids and an increased dependence upon glycolysis.

OBJECTIVES

This study aimed to evaluate whether a shift in substrate use occurs in canine patients with MMVD; a naturally occurring model of human disease.

METHODS

Client-owned dogs were longitudinally evaluated at a research clinic in London, UK and paired serum samples were selected from visits when patients were in ACVIM stage B1: asymptomatic disease without cardiomegaly, and stage C: HF. Samples were processed using ultra-performance liquid chromatography mass spectrometry and lipid profiles were compared using mixed effects models with false discovery rate adjustment. The effect of disease stage was evaluated with patient breed entered as a confounder. Features that significantly differed were screened for selection for annotation efforts using reference databases.

RESULTS

Dogs in HF had altered concentrations of lipid species belonging to several classes previously associated with cardiovascular disease. Concentrations of certain acylcarnitines, phospholipids and sphingomyelins were increased after individuals had developed HF, whilst some ceramides and lysophosphatidylcholines decreased.

CONCLUSIONS

The canine metabolome appears to change as MMVD progresses. Findings from this study suggest that in HF myocardial metabolism may be characterised by reduced β-oxidation. This proposed explanation warrants further research.

Confined Growth of Silver-Copper Janus Nanostructures with {100} Facets for Highly Selective Tandem Electrocatalytic Carbon Dioxide Reduction

Electrocatalytic carbon dioxide reduction reaction (CO₂ RR) holds significant potential to promote carbon neutrality. However, the selectivity toward multicarbon products in CO₂ RR is still too low to meet practical applications. Here the authors report the delicate synthesis of three kinds of Ag-Cu Janus nanostructures with {100} facets (JNS-100) for highly selective tandem electrocatalytic reduction of CO₂ to multicarbon products. By controlling the surfactant and reduction kinetics of Cu precursor, the confined growth of Cu with {100} facets on one of the six equal faces of Ag nanocubes is realized. Compared with Cu nanocubes, Ag₆₅ -Cu₃₅ JNS-100 demonstrates much superior selectivity for both ethylene and multicarbon products in CO₂ RR at less negative potentials. Density functional theory calculations reveal that the compensating electronic structure and carbon monoxide spillover in Ag₆₅ -Cu₃₅ JNS-100 contribute to the enhanced CO₂ RR performance. This study provides an effective strategy to design advanced tandem catalysts toward the extensive application of CO₂ RR.

Catalytic ozonation oxidation of ketoprofen by peanut shell-based biochar: effects of the pyrolysis temperatures

A series of peanut shell (HS)-based biochar were prepared at different pyrolysis temperatures and subsequently used as the effective ozonation catalysts for ketoprofen (KET) degradation in aqueous solution. The physicochemical properties and morphology of the obtained biochar were analysed by ICP, TG, XRD, FT-IR, SEM, TEM, BET and etc. characterizations. The results demonstrated that the pyrolysis temperature played an important role on the structure and morphology of HS-based biochar. As the pyrolysis temperature increased, the cellulose and hemicellulose of HS gradually decomposed, resulting in the loss of biochar mass, improvement of the surface roughness, the increase of specific surface area, and the formation of new functional groups. The HS-based biochar pyrolyzed at 600°C (HS600) achieved the fast KET degradation rate with the pseudo-first-order rate constant of 0.922 min^-1 and the low adsorption rate of 1.3% in O₃/HS600 process. Meanwhile, the effects of the HS600 dosage, initial KET concentration, temperature, water matrix, and solution pH on KET degradation were systematically evaluated. Besides, the HS600 displayed great stability and reusability towards KET degradation during multiple cycling experiments. Moreover, the single oxygen, superoxide radical and hydroxyl radical were involved in O₃/HS600 process and the mechanisms for the improvement of KET degradation were also elucidated. It could be speculated that the enhancement of the catalytic ozonation by HS-based biochar was probably attributed to the increased active sites and the intense chemical bonds, and delocalized π electron.

Enhancing the separation efficiency of photo-induced carriers in a Bi2S3/BiOCl heterostructure by cooperative influence of oxygen vacancies and the interfacial electric field

The outstanding photocatalytic activity of Bi2S3/BiOCl heterostructures derived from enhanced light-utilization efficiency is demonstrated.

Manganese oxide OMS-2 loaded on activated carbon fiber: a novel catalyst-assisted UV/PMS process for carbamazepine treatment in water

A novel catalyst was prepared by loading OMS-2 onto activated carbon fiber (ACF) via a one-step hydrothermal method, which was further adopted for carbamazepine treatment.

Relying on the non-radical degradation of oxytetracycline by peroxymonosulfate activated with a magnetic Cu/Fe composite: performance and mechanism

CuFe-1 nanoparticles were successfully synthesized, and they could effectively activate peroxymonosulfate to assist the degradation of oxytetracycline.

Cu-Doped magnetic loofah biochar for tetracycline degradation via peroxymonosulfate activation

The Cu-doped deactivated magnetic biochar exhibited high PMS activation to degrade TC with a high removal rate of 97.6%.

Vegetation Community Characteristics Under Different Vegetation Eco-restoration Techniques at Xiangjiaba Hydropower Station

The objective of this study is to understand the characteristics of vegetation communities under different vegetation eco-restoration models (vegetation concrete eco-restoration technique, frame beam filling soil technique, thick layer base material spraying technique, and external soil spray seeding technique). Vegetation coverage, dominant species, species composition, and species diversity of vegetation community under different vegetation eco-restoration modes were analyzed by field survey. The vegetation community of the abandoned slag slope was unstable due to the simple vegetation community structure. The species and number of the thick layer base material spraying slope were low and fail to form a healthy multilayer community structure due to invade of Leucaena leucocephala (Lam.) de Wit. Studying the allelopathy of Leucaena leucocephala (Lam.) de Wit and seeking the best species composition that can coexist with it is significant to promote the positive succession of the vegetation community. The frame beam filling soil technique, external-soil spray seeding technique, and vegetation concrete eco-restoration technique can effectively promote the succession process of the vegetation community and have well water and soil conservation capacity. These findings suggest that artificial vegetation eco-restoration measures can effectively promote vegetation eco-restoration and the positive succession of vegetation community of disturbed slopes. The research results can provide scientific advice for vegetation eco-restoration and subsequent control and management of disturbed slopes in the Xiangjiaba project, and also can be helpful to other similar projects.

Tailored d-Band Facilitating in Fe Gradient Doping CuO Boosts Peroxymonosulfate Activation for High Efficiency Generation and Release of Singlet Oxygen

In the field of heterogeneous catalysis, limitations of the surface reaction process inevitably make improving the catalytic efficiency to remove pollutants in water a major challenge. Here, we report a unique structure of Fe surface-gradient-doped CuO that improves the overall catalytic processes of adsorption, electron transfer, and desorption. Interestingly, gradient doping leads to an imbalanced charge distribution in the crystal structure, thereby promoting the adsorption and electron transport efficiency of peroxymonosulfate (PMS). The orbital hybridization of Fe also improves the electronic activity. More importantly, the occupied d-orbital distribution is closer to the lower energy level, which improves the desorption of the reaction intermediate (¹O₂). As a result, the production and desorption of ¹O₂ have been improved, resulting in excellent BPA degradation ability (kinetic rate increased by 67.3 times). Two-dimensional infrared correlation spectroscopy is used to better understand the doping process and catalytic mechanism of Fe-CuO. Fe-O changes before Cu-O and is more active. The Fe-required active sites, active species intensity, and kinetic reaction rates show a good correlation. This research provides a scientific basis for expanding the purification of toxic organic pollutants in complex water environments by heterogeneous catalytic oxidation.

Degradation and regeneration of Fe-N x active sites for the oxygen reduction reaction: the role of surface oxidation, Fe demetallation and local carbon microporosity

The severe degradation of Fe-N-C electrocatalysts during a long-term oxygen reduction reaction (ORR) has become a major obstacle for application in proton-exchange membrane fuel cells. Understanding the degradation mechanism and regeneration of aged Fe-N-C catalysts would be of particular interest for extending their service life. Herein, we show that the by-product hydrogen peroxide during the ORR not only results in the oxidation of the carbon surface but also causes the demetallation of Fe active sites. Quantitative analysis reveals that the Fe demetallation constitutes the main reason for catalyst degradation, while previously reported carbon surface oxidation plays a minor role. We further reveal that post thermal annealing of the aged catalysts can transform the oxygen functional groups on the carbon surface into micropores. These newly formed micropores not only help to increase the active-site density but also the intrinsic ORR activity of the neighbouring Fe-N₄ sites, both contributing to complete activity recovery of aged Fe-N-C catalysts.

[Design and Implementation of Intelligent Monitoring Collar for Potential Patients with Viral Pneumonia Based on DA14699 Chip]

In order to improve the level of epidemic prevention and control, and strengthen the observation and monitoring of potential patients with viral pneumonia in isolated state, a medical intelligent monitoring collar based on DA14699 Bluetooth low-power chip was proposed. DA14699 chip is used as the main controller in the design scheme, and the temperature, cough and location information of potential patients are recorded and analyzed by its high-efficiency wireless multi-core processing ability. The LIS3DH three-axis acceleration sensor is used to judge the cough symptoms. The MLX90640 infrared sensor is used to continuously measure the body temperature. The L218 four frequency GSM / GPRS positioning module is used to complete the rapid and accurate positioning of personnel, so as to realize the comprehensive supervision of the implementation of home isolation measures. DA14699 chip supports Bluetooth BLE5.1 protocol. Epidemic prevention personnel can transmit and read the data recorded in the smart collar from a long distance, and display it directly on the intelligent Bluetooth handheld terminal, effectively avoid the risk of infection caused by close contact. Through the actual test, the monitoring function of the key parameters of the collar is reliable and has high application value.

Copper oxide/graphitic carbon nitride composite for bisphenol a degradation by boosted peroxymonosulfate activation: Mechanism of Cu-O covalency governs

Surface structure can govern heterogeneous catalysis, resulting in its critical role in nonradical reactions. Here, we explored whether Cu-O covalency plays a critical role in controlling the inherent properties of copper oxide/graphitic carbon nitride (CuO-CN). Experiments and theoretical calculations show that, in contrast to the traditional concept of low-valent metal control activity, surface modification enlarges Cu-O covalency, and high-valent copper species at the surface easily bind peroxymonosulfate (PMS, (HSO₅^-)) anions. Therefore, optimized CuO-CN corresponds to a 14.8-fold higher kinetic reaction rate (0.10392 min^-1) for PMS activation and pollutant degradation over those of unoptimized CuO-CN. Based on two-dimensional Fourier transform infrared correlation spectroscopy (2D-FT-IR-COS), Cu-O was determined to be the main active site. Cu-O is more active than other groups and acts before other groups. Benefiting from this electron transfer mechanism, CuO-CN shows good environmental tolerance (pH, anions, humic acid and actual water bodies such as tap water and groundwater). The established empirical kinetic model shows a strong linear correlation with the experimental kinetic reaction rate (> 0.94). CuO-CN/PMS can degrade organic pollutants efficiently for up to 30 days in a filter reactor. This work provides an understanding of the key role of the surface electronic structure in the nonradical activation of PMS and may provide support for improving the design of PMS catalysts.

[Molecular-related epidemic characteristics of influenza A (H3N2) viruses in Guangzhou, 2019]

Objective: To isolate the influenza A (H3N2) viruses from different sources in Guangzhou in 2019 and analyze these viruses' evolution and variation characteristics. Methods: The hemagglutinin (HA) and neuraminidase (NA) genes of H3N2 isolates from outpatient monitoring, influenza outbreaks, and inpatient severe cases in Guangzhou in 2019 were sequenced. Bioinformatics software analyzed the variations and evolution characteristics of HA and NA genes. Results: The epidemic peaks of influenza A (H3N2) viruses were made up of period Ⅰ (from January to August) and period Ⅱ (from November to December). The positive rate of influenza A (H3N2) in males was 13.46% (703/5 221), which was higher than that in females (11.50%, 510/4 435) (χ²=8.43,P=0.00). The group's positive rate of 10-20 years old was the highest (25.18%,665/2 641). The isolates from different sources were highly homologous and closely related to 3C.2a.1 branches, which could be further divided into three small groups of Group 1-3. Gene recombination was observed between different branches. The mutations of HA antigen sites gradually appeared from Group 1 to Group 3, leading to new antigen drift. Variations of HA antigenic sites mainly occurred in the region of A and B. The mutations of receptor binding sites of Group 1 and Group 3 viruses occurred in the anterior and posterior walls. There were two glycosylation sites lacked on region A of HA antigen observed in the isolates of Group 2-3. Conclusions: Genetic variations of H3N2 influenza viruses in Guangzhou included gene mutations and gene recombination. Under the pressure of the vaccine, the evolution of viruses was rapid. Therefore, the monitoring of molecular-related epidemic characteristics of the H3N2 influenza virus was necessary.

Synergistic mechanism and degradation kinetics for atenolol elimination via integrated UV/ozone/peroxymonosulfate process

The present research systematically investigates the atenolol (ATL) degradation in integrated UV/Ozone (O₃)/peroxymonosulfate (PMS) process focusing on the synergistic mechanism, reaction kinetics, pollutant degradation pathway and antibacterial activity. The results manifested that the integrated UV/O₃/PMS process showed the noteworthy superiority to ATL degradation compared with UV/PMS, UV/O₃ and O₃/PMS systems. Simultaneously, the impacts of operating parameters like PMS dosage, initial ATL concentration, solution pH and water matrix were comprehensively explored. The ATL elimination efficiency increased linearly with PMS dose and significantly enhanced in alkaline conditions. The ^•OH and SO₄^•- were the primary reactive radicals for ATL oxidation in UV/O₃/PMS system based on the radical scavenging experiments and electron paramagnetic resonance characterization. Besides, a simplified kinetic model on the basis of the dominant reactions and the steady-state assumption was established to foretell the relative contributions of reactive oxidants for ATL elimination in UV/O₃/PMS process. Main transformation products were determined via UPLC-QTOF-MS to infer the possible degradation pathways of ATL. Furthermore, the UV/O₃/PMS process could distinctly mitigate the antibacterial activity of ATL and its intermediates to E. coli and B. subtilis. Our findings may have critical implications for the development of novel oxidation processes for recalcitrant contaminants mitigation in water purification.

Study on the adsorption and desorption performance of magnetic resin for Congo red

This study was to evaluate the adsorption capability of a magnetic resin (NDMP) to the removal of Congo red (CR) from aqueous solution. The adsorption kinetic and isotherm of NDMP were studied, as well as the desorption performance of NDMP. The results showed that the adsorption process of NDMP on CR was more suitable for Pseudo-second-order kinetic model. The whole adsorption process was affected by intraparticle diffusion and ion exchange. The adsorption isotherm of CR by NDMP was fitted better with Langmuir model. It showed that the adsorption of CR on NDMP resin was single layer adsorption. The maximum adsorption capacity (Q_m) of CR at 308 K can reach 354.29 mg/g. In the desorption, 10% NaCl and NaOH eluents had better desorption rate for CR than other mass fraction. While NaCl(10%)-MeOH mixed eluent with volume ratio of 3:7 had the best regeneration performance. The desorption rate can reach 90% within 30 min. The adsorption performance of NDMP on CR didn't decrease after 13 times successive adsorption-desorption by NaCl(10%)-methanol eluent, indicating that NDMP can be efficiently regenerated. The excellent adsorption-desorption performance of NDMP on CR suggests that the magnetic resin has a great potential for treating CR dye wastewater.

Efficient persulfate non-radical activation of electron-rich copper active sites induced by oxygen on graphitic carbon nitride

Peroxymonosulfate (PMS) non-radical reactions possess high catalytic activity for specific pollutants under complex water environments. However, the synthesis of high-performance catalysts and the discussion of non-radical reaction mechanisms are still unsatisfactory. Here, a novel and efficient non-radical catalyst (O-CuCN) was successfully assembled using the scheme of Copper (Cu) and oxygen (O) co-doping. The O element with great electronegativity induces graphite carbon nitride (g-C₃N₄) to act as a medium to change the phase properties and electron density distribution of g-C₃N_4, and provides a support for the targeting of Cu. Cu is introduced into g-C₃N₄ as an active site in the phase structure, and an electron-rich center with the Cu site is formed, which forms a metastable intermediate after the adsorption of PMS by Cu as the active site. The new catalyst O-CuCN has outstanding activity in the PMS system, and its degradation rate for bisphenol A (BPA) is increased by more than 20 times compared to that of g-C₃N₄, and it has excellent environmental tolerance and stability. This work demonstrates that the formation of metastable intermediates and the initiation of effective non-radical reactions can be achieved by constructing differentiated electron density structures.