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This study objective is to degrade xanthate from flotation tailings wastewater by using a coagulation-flocculation co-Fenton oxidation process in an acid mine drainage (AMD)-H2O2 system. More than 98% sodium butyl xanthate (SBX) removal rate was achieved by the method under optimal conditions. The acids and Fe2+ in AMD were sufficient to initiate a Fenton reaction at the aid of H2O2. Furthermore, iron ions were reduced to an extremely low level (0.19 mg/L) by participating in an oxidation process. Meanwhile, the Cu2+ ions in AMD facilitated the coagulation-flocculation process. Comparison experiments confirmed that the method was superior to the AMD alone (54.26%) and H2O2 alone (32.23%) in terms of performance in degrading SBX. The kinetic results showed that SBX degradation followed a pseudo first-order kinetic model. Additionally, the electron paramagnetic resonance (EPR) and quenching results suggested that hydroxyl radicals (â¢OH) were the main active species in AMD-H2O2 system. Degradation products were analyzed, and two possible pathways of SBX degradation were proposed. One pathway displayed that the SBX was first transformed into butyl xanthate peroxide (BPX), CO32- and S2O32-, and then further decomposed into CO2, H2O and SO42- under the ongoing â¢OH attack. Another pathway showed that precipitates consisting of butyl copper xanthate and iron oxide species were generated during the SBX degradation. This study provides a novel perspective on the innovative application of AMD in Fenton oxidation and provides a strong basis for the green and sustainable treatment of xanthate wastewater in tailings.
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Águas Residuárias , Poluentes Químicos da Água , Peróxido de Hidrogênio , Poluentes Químicos da Água/análise , Ferro , Oxirredução , ÁcidosRESUMO
China has implemented various policies and measures for controlling air pollutants. However, our knowledge of the long-term trends in ambient volatile organic compounds (VOCs) after the implementation of these action plans in China remains limited. To address this, we conducted a five-year analysis (2016-2020) of VOC compositions and concentrations in Beijing. The annual VOC concentration decreased from 44.0 ± 28.8 to 26.2 ± 16.4 ppbv, with alkanes being the most prevalent group. The annual average concentrations of alkenes, alkynes, and aromatics have experienced a significant decrease of over 50 %. Seasonal variations indicated higher VOC concentrations in winter and autumn, with more significant reductions observed in winter and autumn. The impact of meteorological conditions caused variations in VOC reductions during the Chinese Spring Festival. Satellite-based measurements of formaldehyde (HCHO) columns confirmed the reduction of VOC emissions during the Coronavirus (COVID-19) lockdown. The normalized annual average VOC concentration decreased by 2.9ppbv yr-1 from 2016 to 2020, and emission reduction contributed to 58.8 % of VOC reduction from 2016 to 2020 after meteorological normalization, indicating the effectiveness of implemented control measures. Based on receptor model, vehicle emissions and industrial sources were identified as the largest contributors to VOC concentrations. Vehicle emissions, liquefied petroleum gas/natural gas (LPG/NG) use, and coal combustion were major drivers of VOC reduction. Potential source region analysis revealed that air masses transported from northwestern and southern regions significantly contributed to VOC concentrations in Beijing. The range of source regions shrunk in both northwestern and southern regions with the reduction in VOC concentrations. The annual variations of ozone formation potential indicated a significant decrease in VOC reactivities through emission control. These results could provide insights into future emission control and coordinated efforts to improve PM2.5 and ozone levels in China.
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As a common cause for food-borne diseases, the Salmonella spp. are generally prevalent among livestock, whereby they are likely to be transmitted to human via environmental contamination. To explore the potential mechanism for prevalence of MDR Salmonella and its risk for dissemination via contaminated environments, we profiled the colonization dynamics of MDR Salmonella in chicken, herein we found that an adaptive evolution, driven by mutagenesis in a small protein-encoding gene (STM14_1829), conferred the multidrug resistant (MDR) Salmonella with increased fitness in asymptomatic host. Then the mechanistic study demonstrated that only one amino acid substitution in small protein STM14_1829 rendered MDR Salmonella capable to better invade and persist in phagocytotic cells by modulating bacterial flagella overexpression. Concerningly, the evolved Salmonella was also more resilient to the potential stressors generally found in environments and food processing, including heat, cold, adverse pH and oxidations. It implied that the evolved subpopulations are plausibly more persistent in environments once they contaminated through animal manure or human excreta. Moreover, the evolution promoted the pathogenesis caused by MDR Salmonella in susceptible hosts, resulting in higher risk for dissemination of pathogens via contaminated environments. Together, our data provided the novel insights into that in vivo adaptive evolution benefits Salmonella colonization, persistence and pathogenesis, by promoting bacterial tolerance via modulating flagella expression. These findings may explain the rationale behind the increasing prevalence of certain MDR Salmonella clones in livestock and associated environment, and underscoring the need for advanced strategies to tackle the possible evolution of such zoonotic pathogens.
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Antibacterianos , Doenças Transmitidas por Alimentos , Animais , Humanos , Antibacterianos/farmacologia , Virulência , Salmonella/genética , Bactérias , Farmacorresistência Bacteriana Múltipla/genéticaRESUMO
The proper treatment and utilization of oily sludge (OS) and incineration fly ash (IFA) remains a significant challenge due to their hazardous nature. To attain effective recovery of petroleum hydrocarbons and synergistic disposal, this study investigated the co-pyrolysis of OS and IFA, resulting in successful energy recovery, CO2 mitigation, and heavy metal immobilization. Results revealed that the peak ratio of light oil to heavy oil fractions reached 179.42% with 20 wt% IFA addition, accompanied by the highest aromatic hydrocarbons selectivity of 30.72% and the lowest coke yield of 106.13 mg/g OS under the optimal temperature of 600 °C. In-depth analysis indicated that IFA inhibited the poly-condensation of macromolecular PAHs and promoted their cracking into light aromatic hydrocarbons. The addition of 50 wt% IFA significantly increased H2 yield (21.02 L/kg OS to 60.95 L/kg OS) and facilitated CO2 sequestration due to its higher content of Ca-bearing minerals. Moreover, high IFA ratios promoted the reduction of Fe species in OS to a low-valence state. Heavy metals in co-pyrolysis char were well immobilized into stable fractions with lower environmental risks. This work highlights the potential of co-pyrolysis as a viable approach for simultaneous disposal of multiple hazardous wastes and offers new insights for their utilization.
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Studying microplastics and nanoplastics (MNP) in environmental matrices is extremely challenging, and recent developments in labelling techniques may hold much promise to further our knowledge in this field. Here, we reviewed MNP labelling techniques and applications to provide the first systematic and in-depth insight into MNP labelling. We classified all labelling techniques for MNP into four main types (fluorescent, metal, stable isotope and radioisotope) and discussed per type the synthesis methods, detection methods, influencing factors, and the current and future applications and challenges. Direct labelling of environmental MNP with fluorescent dyes and metals enables simple visualisation and selective detection of MNP to improve detection efficiency. However, it is still an open question how to avoid co-labelling of non-plastic (i.e. non-target, matrix) materials. Labelling of MNP that are intentionally added in the environment may allow semi-automatic detection of MNP particles with high accuracy and sensitivity during studies on e.g. transport and degradation. The detection limit of labelled MNP largely depends on particle size and the type of matrix. Fluorescent labelling allows efficient detection of microplastics, whereas metal labelling is preferred for nanoplastics research due to a potentially higher sensitivity. A major challenge for fluorescent and metal labelling is to develop techniques that do not alter the inherent MNP properties or only do so minimally, in particular the surface properties. Stable and radioactive isotope labelling (13C and 14C, but also 15N, 2H) of the polymer itself allows to preserve inherent MNP properties, but have been largely ignored. Overall, labelling of MNP holds great promise for advancing our fundamental understanding of the behaviour of plastics, notably the smallest fractions, in the environment.
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OBJECTIVES: The purpose of this study was to explore whether psychological resilience can influence changes in cognitive function in older adults and provide clues and rationale for improving cognitive function and preventing the onset of dementia in the geriatric population. METHODS: A total of 2495 older adults aged 60 years or older from the Ma' anshan Healthy Aging Cohort were included in the study. Participants' cognitive functioning and psychological resilience were measured using the MMSE (mini-mental state examination) scale and the SRQS (stress resilience quotient scale) scale during the 5 years of follow-up, and the association was explored. Those with MMSE scores ≤ 17 in the illiterate group, ≤ 20 in the elementary school group, and ≤ 24 in the secondary school and above group were considered cognitive impairment. RESULTS: The prevalence of cognitive impairment increased from 6.89% to 14.30% during the five years of follow-up. At 5-year follow-up, the group with the highest psychological resilience had 41 (6.83%) individuals whose cognitive functioning changed from normal to cognitive impairment, while the group with the worst psychological resilience had 114 (18.33%) individuals. The study also found a significant effect of different levels of psychological resilience on changes in cognitive functioning after adjusting for potential confounders. Compared with Q1 (the reference group), the Odds ratio of cognitive decline in Q2, Q3 and Q4 groups were 0.51(0.42,0.64), 0.37(0.29,0.47) and 0.19(0.13,0.27), respectively. CONCLUSIONS: Improving the level of psychological resilience in older adults may be one way to prevent the incidence of cognitive impairment.
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Disfunção Cognitiva , Envelhecimento Saudável , Resiliência Psicológica , Humanos , Idoso , Estudos de Coortes , Cognição , Disfunção Cognitiva/psicologiaRESUMO
Wide usage of plastic coupled with mismanagement has created a humongous environmental hazard threatening entire ecosystems. To date, the potential effects of plastic debris-induced soil nutrition substance changes and the relevant microbial metabolic behavior remain unclear. Here, we studied the effect of plastic films polyethylene and polylactic acid in differential soil environments (farmland, woodland, and wetland) for 120 days. Soil enzyme activities (urease, neutral phosphatase, and catalase) and nutrition substance (NH4+-N, available P, available K, and soil organic matter) present obvious variations in polylactic acid groups compared to polyethylene-treated samples. 16S rRNA gene sequencing indicates that several bacteria abundance such as Bacteroidales, Actinobacteriota, Nitrososphaeraceae, Pyrinomonadalcs, Muribaculaceae, exhibited obvious up-regulation or down-regulation, and simultaneously, the carbon, nitrogen, and phosphorus cycling relevant species Bryobacter, Bradyrhizobium, and Sphingomonas, expressed wider margin of down-regulation in abundance in plastic treatment soil samples. As a result, the abundance of metabolites including sugar, amino acid, and fatty acids, which may associated with nutrition substance metabolic pathways, were significantly altered in the stress of plastic. These findings provide valuable information on the environmental effects of plastics, and the relationships of subsequent nutrition substance changes and microbial metabolic behavior.
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Microbiota , Solo , Solo/química , RNA Ribossômico 16S , Bactérias , Polietileno , Bacteroidetes , Microbiologia do Solo , PlásticosRESUMO
Primary dolomite is believed to be formed through cyanobacterial calcification, yet the details and mechanisms of this process are not fully understood. In this study, a freshwater filamentous cyanobacterium, Leptolyngbya boryana, was cultured and domesticated in artificial freshwater and brackish solutions with various Mg/Ca ratios. The hydrochemistry, the extracellular polymeric substance (EPS) composition, and precipitate mineralogy in the medium were monitored. The results showed that the L. boryana induced proto-dolomite precipitation in brackish medium with salinity of 1.5 % and Mg/Ca ratio of 5. The proto-dolomite in this study has a "double spherical" appearance and a hollow core, which may have originally been filled by the complex composed of EPS and amorphous CaMg carbonate. With regard to elemental composition, the cyanobacterially-induced proto-dolomite is rich in calcium inside and magnesium-rich on the surface, and cyanobacterial organic matter is sealed inside the particles during spherulite growth. In this study, the accelerators for Mg2+ to enter the carbonate lattice mainly include extracellular acidic amino acids and polysaccharides. The changes of these promoters among different cultures were related to the growth state of cyanobacteria under salinity stress. The polysaccharides concentration has a significant increasing in the dolomite-precipitating medium, indicating that it may be the main promoter of proto-dolomite precipitation and significantly increases the amount of Mg2+ precipitation. At the meantime, the amount of precipitated Ca2+ was suppressed by increasing salinity and Mg2+, thus leading to the precipitation of proto-dolomite in this shifting process. This study can potentially provide a reference for explaining the dolomite (proto-dolomite) precipitation in aerobic brackish environment where cyanobacteria thrive.
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Cianobactérias , Magnésio , Magnésio/química , Matriz Extracelular de Substâncias Poliméricas/metabolismo , Cianobactérias/metabolismo , Carbonato de Cálcio/química , Água Doce , Águas Salinas , Polissacarídeos/metabolismoRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Saposhnikoviae Radix (SR) is a traditional Chinese medicine, known as "Fangfeng". As one of the main active components, Saposhnikoviae Radix polysaccharides (SP) demonstrated a range of biological activities, especially immunity regulation activity. AIMS OF THE STUDY: This study aimed at exploring whether polysaccharides have activity after degradation, then discovering the potential effective fragments of SP. MATERIALS AND METHODS: Here we establish the chromatographic fingerprints method for 32 batches of 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatives of oligosaccharides by HPLC, meanwhile evaluating its immunomodulatory activity in vivo. Then, the potential effective fragments of SP were screened out based on the spectrum-effect relationship analysis between fingerprints and the pharmacological results. Besides, liquid chromatography ion trap-time of flight mass spectrometry (LC-IT-TOF MS) coupled with multiple data-mining techniques was used to identify the potential effective oligosaccharides. RESULTS: These findings showed that the hydrolysate of SP have significant immunomodulatory, and the immunity regulation activity varies under different hydrolysis conditions. The 4 potential effective peaks of the hydrolysate of SP were mined by spectrum-effect relationship. Finally, the chemical structure of 4 potential effective oligosaccharide fragments of SP was elucidated based on LC-IT-TOF MS. F10 was inferred tentatively to be Hex1â6Hex1â6Hex1â6Hex1â6Hex1â6Gal; F18 was confirmed to be Rhamnose; F14 was inferred tentatively to be Hex1â4Hex1â 4Hex1â4Gal and F25 was tentatively inferred to be Ara1â6Gal. CONCLUSIONS: This study may provide a sound experimental foundation in the exploration of the active fragments from macromolecular components with relatively complex structures such as polysaccharides.
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Medicamentos de Ervas Chinesas , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/química , Cromatografia Líquida , Cromatografia Líquida de Alta Pressão/métodos , Polissacarídeos/farmacologia , Polissacarídeos/análise , Oligossacarídeos/farmacologiaRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Pulmonary injury and fibrosis can be caused by various factors because of their inflammatory nature, both can lead to serious clinical consequences. Inula japonica Thunb. is used in traditional Chinese medicine for the treatment of lung diseases. However, the effect and mechanism of action of the essential oil of I. japonica (EOI) on pulmonary injury and fibrosis are not well understood. AIM OF THE STUDY: To investigate the therapeutic effects of EOI on mice with bleomycin (BLM)-induced acute pulmonary injury and chronic fibrosis formation, as well as its potential mechanism. MATERIALS AND METHODS: A short-term mouse model of pulmonary injury was established by intratracheal injection of BLM to investigate the anti-inflammatory effect of EOI, and a long-term model of pulmonary fibrosis was used to explore the anti-fibrosis effect of EOI. High-dose EOI (200 mg/kg) was administered intragastrically, and low-dose (50 mg/kg) was administered by intratracheal injection. Gas chromatography-mass spectrometry (GC-MS) was used to identify the ingredients in EOI, and high-performance liquid chromatography (HPLC) was performed for the preparation of EOI compounds. Western blot and real-time qPCR were used to verify the effects of EOI and its active composition on inflammation, oxidative stress and fibrosis signaling pathway. RESULTS: Treatment with EOI significantly reduced the inflammation and oxidative stress by reducing the levels of inflammatory and oxidative cytokines such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and malondialdehyde in BLM-treated mice with acute pulmonary injury. EOI treatment could also suppress the formation of fibrous tissue in mice with BLM-induced pulmonary fibrosis through inhibiting TGF-ß/Smad and PI3K/Akt pathways. Chromatographic analysis and preparation suggested that fatty acid and phenol derivatives are present in EOI. Based on cellular inflammation and fibrosis models, the phenolic compounds in EOI can represent the anti-inflammatory and anti-fibrotic effects of EOI by regulating pro-inflammatory and pro-fibrotic cytokines such as NO, TNF-α, IL-6, TGF-ß1, and α-SMA. CONCLUSION: EOI ameliorated BLM-induced pulmonary injury and fibrosis in mice by inhibiting the inflammatory response and regulating the redox equilibrium, as well as by mediating TGFß/Smad and PI3K/Akt, which suggested that EOI has potential to treat pulmonary diseases.
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Inula , Lesão Pulmonar , Óleos Voláteis , Fibrose Pulmonar , Camundongos , Animais , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/tratamento farmacológico , Fibrose Pulmonar/patologia , Bleomicina/toxicidade , Lesão Pulmonar/tratamento farmacológico , Fator de Necrose Tumoral alfa/metabolismo , Interleucina-6/metabolismo , Óleos Voláteis/farmacologia , Óleos Voláteis/uso terapêutico , Óleos Voláteis/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fibrose , Inflamação/tratamento farmacológico , Citocinas/metabolismo , Anti-Inflamatórios/efeitos adversos , Fator de Crescimento Transformador beta/metabolismo , Fenóis/farmacologia , PulmãoRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Previous studies have found that Yang-Xin-Shu-Mai granule (YXSMG) has certain advantages in the treatment of stable coronary heart disease. However, YXSMG can inhibit the progression of atherosclerotic plaque and stabilize vulnerable plaque needs to be further explored and studied. This research, mass spectrometry analysis, network pharmacology, in vivo and in vitro experimental studies were conducted to explore the mechanism of YXSMG on atherosclerosis. AIM OF THE STUDY: To decipher the mechanism of atherosclerotic plaque, stabilization for YXSMG by analysis of its active ingredients and biological network and activity in whole animal and at cellular and molecular levels. METHODS: The active components of YXSMG were determined using high performance liquid chromatography-mass spectrometry/mass spectrometry (HPLC-MS/MS) analysis. The 'Disease-Compound-Target-Pathway' network diagram was constructed using network pharmacology, and the stability of binding between core targets and core compounds was analyzed with molecular docking. After intervention with YXSMG, the pathology of aortic plaque, inflammation in the surrounding tissue, expression of TLR9/MyD88/NF-κB pathway protein in plaque and M1/M2 polarization of plaque macrophages were evaluated in vivo in apolipoprotein E-deficient (ApoE-/-) mice fed with high-fat diet. To verify whether it suppressed inflammation by inhibiting Toll-like receptor 9 (TLR9) reprogramming of macrophage polarization, we used RAW264.7 macrophages treated with specific TLR9 agonist (ODN1826) and inhibitor (ODN2088). RESULTS: Five active compounds were identified in YXSMG: catechin, formononetin, tanshinone IIA, cryptotanshinone and glycitein. Network pharmacology studies revealed TLR9 as one of the core targets of YXSMG intervention in atherosclerosis. Computer simulation of molecular docking showed that TLR9 could interact with the core compound to form a stable complex. In vivo experiments confirmed that YXSMG could significantly inhibit atherosclerotic plaque, reduce levels of blood lipids and inflammatory factors, downregulate TLR9/MyD88/NF-κB pathway protein and inhibit aortic sinus macrophages polarization to M1, but promote their polarization to M2 to inhibit inflammation. In vitro experiments revealed that YXSMG could downregulate expression of TLR9 gene and protein in ODN1826-activated RAW264.7 macrophages. ODN2088 had a synergistic effect with YXSMG on the TLR9/MyD88/NF-κB signaling pathway, and reprogrammed macrophages polarization from M1 to M2 by inhibiting TLR9, thus reducing immuno-inflammatory response. CONCLUSION: YXSMG can reduce the level of blood lipid and improve the size of atherosclerotic plaque and inflammatory infiltration in ApoE-/- mice fed with high fat. It is concluded that YXSMG can improve the mechanism of atherosclerotic plaque by inhibiting TLR9/MyD88/NF-κB pathway reprogramming macrophage M1/M2 polarization and reducing arterial inflammation.
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Aterosclerose , Placa Aterosclerótica , Camundongos , Animais , Placa Aterosclerótica/patologia , NF-kappa B/metabolismo , Fator 88 de Diferenciação Mieloide/metabolismo , Receptor Toll-Like 9/metabolismo , Simulação por Computador , Simulação de Acoplamento Molecular , Espectrometria de Massas em Tandem , Aterosclerose/genética , Transdução de Sinais , Macrófagos , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Inflamação/patologia , Lipídeos/farmacologia , Apolipoproteínas E/genética , Camundongos Endogâmicos C57BLRESUMO
Vascular etiology is the second most prevalent cause of cognitive impairment globally. Endothelin-1, which is produced and secreted by endothelial cells and astrocytes, is implicated in the pathogenesis of stroke. However, the way in which changes in astrocytic endothelin-1 lead to poststroke cognitive deficits following transient middle cerebral artery occlusion is not well understood. Here, using mice in which astrocytic endothelin-1 was overexpressed, we found that the selective overexpression of endothelin-1 by astrocytic cells led to ischemic stroke-related dementia (1 hour of ischemia; 7 days, 28 days, or 3 months of reperfusion). We also revealed that astrocytic endothelin-1 overexpression contributed to the role of neural stem cell proliferation but impaired neurogenesis in the dentate gyrus of the hippocampus after middle cerebral artery occlusion. Comprehensive proteome profiles and western blot analysis confirmed that levels of glial fibrillary acidic protein and peroxiredoxin 6, which were differentially expressed in the brain, were significantly increased in mice with astrocytic endothelin-1 overexpression in comparison with wild-type mice 28 days after ischemic stroke. Moreover, the levels of the enriched differentially expressed proteins were closely related to lipid metabolism, as indicated by Kyoto Encyclopedia of Genes and Genomes pathway analysis. Liquid chromatography-mass spectrometry nontargeted metabolite profiling of brain tissues showed that astrocytic endothelin-1 overexpression altered lipid metabolism products such as glycerol phosphatidylcholine, sphingomyelin, and phosphatidic acid. Overall, this study demonstrates that astrocytic endothelin-1 overexpression can impair hippocampal neurogenesis and that it is correlated with lipid metabolism in poststroke cognitive dysfunction.
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Mo(VI) (MoO42-) removal by aluminum electrocoagulation (Al EC) with Al as anodes and cathodes was studied for the first time. At the initial Mo concentrations of 0.3 - 150 mg/L, kinetic analysis and effects of main factors (electrode connection modes, current density (CD), initial pH, and electrolytes) were examined, and potential mechanism of Mo(VI) removal were elucidated. Results showed that CD had significant impacts on anode weight loss, cathode weight loss, and total electrode weight loss (p value < 0.05). Cathode weight loss was higher than anode weight loss. XRD analysis results showed lower crystallinity of scums than that of precipitates. Boehmite was the most prevalent oxide in scums. An appropriate amount of NaCl was beneficial for enhancing the Mo(VI) removal efficiency and reducing the energy consumption of the Al EC process. Electrostatic attraction, surface complexation, hydroxyl exchange, flocculation, and coprecipitation were the main mechanisms involved in the Mo(VI) removal process by Al EC. Al EC outperformed conventional chemical coagulation in terms of Mo(VI) removal at the same dosage of Al. The Mo(VI) removal efficiencies in two real water samples (lake water and river water) reached up to 89.2% and 71.2%, respectively. This study provides novel insights into the strategies for the removal of oxoanionic metal pollutants and reduction of operating cost by Al EC technology.
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Oxygen evolution reaction (OER) is a multi-electron transfer process, whose intrinsic sluggish dynamic restricts the whole process of overall water splitting (OWS). To address this issue, a porous transition metal sulfide (TMS) catalyst with rich heterojunctions was prepared by vulcanization and trace Fe doping of CoMo-based metal-organic framework (MOF). In this work, the nanoflower composed of ultrathin 2D nanosheets anchored on a nickel foam presents a layered interface that contributes to the exposure of active regions. The resulting electrode denoted as Fe@CoMo2S4/Ni3S2/NF required a low overpotential (η10 = 167 mV @ 10 mA cm-2, η50 = 260 mV @ 50 mA cm-2) in 1.0 M KOH for OER and a small cell voltage (E = 1.513 V @ 10 mA cm-2) to power OWS when coupled with commercial Pt/C. It also exhibited splendid morphological and chemical stability with virtually invariant polarization curve and flower-like appearance after 1000 CV cycles, as well as long-term durability over 100 h with a constant current density of 10 mA cm-2. This work revealed the multi-anionic regulation mechanism in the surface reconstruction of sulfide electrocatalysts, and verified that Co/Mo/Ni-based oxysulfide was the true active substance of OER, which inspired the understanding and design of multi-anionic regulated electrocatalysts.
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Shape memory polymers (SMPs), as a type of smart materials, possess the unique shape memory and deformation recovery abilities. Hence, SMPs have been attracted extensive attentions and widely used in fields of electric devices, aerospace structures and biomedical engineering. Chitosan (CS), as a renewable natural biomass material, exhibits the excellent biocompatibility, biodegradability and antibacterial activities. Using biomass CS as SMPs matrix materials could greatly enhance the environmental friendliness and adaptability, promoting the applications in fields of biomedical engineering and smart devices. This paper provides a detailed overview of current research progress about CS-based SMPs, including diverse stimuli responsiveness, multifunctionalities and various applications. Though, the research on CS-based SMPs is still in the early stage, which exhibits extensive prospect and potential, and could be of significance in advancing smart biomedical technologies.
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Soil redox potential (Eh) plays an important role in the biogeochemical cycling of soil nutrients. Whereas its effect soil process and nutrients' availability under elevated atmospheric CO2 concentration and warming has seldom been investigated. Thus, in this study, a field experiment was used to elucidate the effect of elevated CO2 concentration and warming on soil Eh, redox-sensitive elements and root radial oxygen loss (ROL). We hypothesized elevated CO2 and warming could alter soil Eh by promoting or inhibiting ROL. We found that soil Eh in the rhizosphere was significantly higher than that of non-rhizosphere. Elevated CO2 enhanced soil Eh by 11.5%, which corresponded to a significant decrease in soil Fe2+ and Mn2+concentration. Under elevated CO2, the concentration of Fe2+ and Mn2+ decreased by 14.7% and 13.7%, respectively. We also found that elevated CO2 altered rice root aerenchyma structure and promoted rice root ROL. Under elevated CO2, rice root ROL increased by 79.5% and 112.2% for Yangdao 6 and Changyou 5, respectively. Warming had no effect on soil Eh and rice root ROL. While warming increased the concentration of Mn2+ and SO42- by 4.9% and 19.3%, respectively. There was a significant interaction between elevated CO2 and warming on Fe2+ and Mn2+. Under elevated CO2, warming had no effect on the concentration of Fe2+ but decreased Mn2+ concentration significantly. Our study demonstrated that elevated atmospheric CO2 in the future could increase soil Eh by promoting rice root ROL, which will alter some soil nutrients' availability, such as Fe2+ and Mn2+.
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Oryza , Poluentes do Solo , Solo/química , Dióxido de Carbono , Oxigênio , Oxirredução , Oryza/química , Poluentes do Solo/análiseRESUMO
BACKGROUND: Lotus rhizome juice (LRJ) is susceptible to the Maillard reaction (MR) and caramelization, which tend to cause a reduction in quality and lower consumer acceptance of the product. 1,2-Dicarbonyl compounds (DCs) and heterocyclic compounds have attracted increasing attention as key intermediates responsible for the formation of brown pigments during MR and caramelization. However, little is known about the effects of these two types of compounds on brown pigments in LRJ during sterilization. This study quantified the changes in brown intensity (A420), DCs, and heterocyclic compounds before and after spiking, and identified the precursors and intermediates for brown pigment formation as well as the formation pathways of the intermediates. RESULTS: The spiking experiments suggested that spiking with fructose resulted in more 3-deoxyglucosone (3-DG) and 2,3-dihydro-3,5-dihydroxy-6-methyl-4(H)-pyran-4-one (DDMP), while that with lysine led to more glucosone (GS) and 2,3-butanedione (2,3-BD) in LRJ. The addition of glucose, asparagine, and glutamine promoted the formation of 5-hydroxymethylfurfural (HMF) significantly, whereas the addition of glucose, lysine, and asparagine resulted in more norfuraneol. Spiking with reducing sugars and amino acids promoted both glyoxal (GO) and methylglyoxal (MGO), and the effect of glucose on GO was particularly significant. Correlation analysis showed that A420 had the highest correlation with 3-DG in the fructose- and lysine-spiked group, and with HMF in the glucose-, asparagine-, and glutamine-spiked groups. CONCLUSION: This study revealed that fructose, glucose, asparagine, glutamine, and lysine were essential precursors of MR and caramelization in LRJ during sterilization. 3-Deoxyglucosone and DDMP were mainly produced by caramelization with fructose as the primary precursor, whereas GS and 2,3-BD were primarily formed via MR with lysine catalysis. The MR and caramelization were the main formation pathways of HMF (catalyzed by asparagine and glutamine) and norfuraneol (catalyzed by lysine and asparagine), with glucose as the critical precursor. Methylglyoxal was mainly produced by MR or caramelization, and caramelization was the main formation pathway of GO, with glucose as the precursor. Dor brown pigment formation from fructose and lysine, 3-DG was identified as the most crucial intermediate, while for that from glucose, asparagine, and glutamine, HMF was found to be the most important intermediate. © 2023 Society of Chemical Industry.
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Compostos Heterocíclicos , Lotus , Lotus/metabolismo , Aldeído Pirúvico/análise , Lisina , Asparagina , Glutamina , Rizoma/química , Glucose/química , Reação de Maillard , Frutose/química , Glioxal/análise , EsterilizaçãoRESUMO
Potato is the third most important food crop in the world. Diverse pathogens threaten sustainable crop production but can be controlled, in many cases, through the deployment of disease resistance genes belonging to the family of nucleotide-binding, leucine-rich-repeat (NLR) genes. To identify effective disease resistance genes in established varieties, we have successfully established SMRT-AgRenSeq in tetraploid potatoes and have further enhanced the methodology by including dRenSeq in an approach that we term SMR-AgRenSeq-d. The inclusion of dRenSeq enables the filtering of candidates after the association analysis by establishing a presence/absence matrix across resistant and susceptible varieties that is translated into an F1 score. Using a SMRT-RenSeq-based sequence representation of the NLRome from the cultivar Innovator, SMRT-AgRenSeq-d analyses reliably identified the late blight resistance benchmark genes Rpi-R1, Rpi-R2-like, Rpi-R3a, and Rpi-R3b in a panel of 117 varieties with variable phenotype penetrations. All benchmark genes were identified with an F1 score of 1, which indicates absolute linkage in the panel. This method also identified nine strong candidates for Gpa5 that controls the potato cyst nematode (PCN) species Globodera pallida (pathotypes Pa2/3). Assuming that NLRs are involved in controlling many types of resistances, SMRT-AgRenSeq-d can readily be applied to diverse crops and pathogen systems.
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To realize the quantum anomalous Hall (QAH) effect in two-dimensional (2D) intrinsic magnetic materials, which combines insulating bulk states and metallic edge channel states, is still challenging in experiment. Here, based on first-principles calculations, we predicted two stable kagome-latticed QAH insulators: Cr3Se4 and Fe3S4 monolayers, with the Chern number C = 1. It is found that both structures exhibit a large magnetic anisotropy energy and sizable band gaps, and a topological phase transition from C = -1 to C = 1 occurs when the magnetization orientation changes from the z-axis to the -z-axis. Remarkably, the non-trivial topological properties are robust against biaxial strains of up to ±6%. Furthermore, a variable high Chern number of C = 2 or C = 3 can be observed by stacking two or three layers of the QAH monolayer with an MoS2 insulator. Our results signify that such layered kagome materials can be promising platforms for exploring novel QAH physics.
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Landfill leachate nanofiltration concentrate is a kind of wastewater containing high concentrations of color and refractory organics. Herein, we proposed a novel three-dimensional electrochemical technology (3DET) with waste aluminum scraps as particle electrodes for its treatment. The planar and particle electrodes were first optimized. Ti/RuO2 and graphite were used as anodes in the two-dimensional electrochemical technology (2DET). In the light of contaminant removal (color, UV254, COD, and TOC), chlorine reduction, and energy consumption, graphite was selected as planar anodes and cathodes. Moreover, 3DET with Al particle electrodes (Al 3DET) outperformed that with conventional granular activated carbon electrodes, 2DET, and Al particles. At 120 min, the removal efficiencies of color, UV254, COD, and TOC using Al 3DET were 98.94 %, 84.72 %, 51.93 %, and 67.46 %, respectively. UV-vis and EEM spectroscopy, and GC-MS analyses indicate that macromolecular organic matter such as humic-like substances could be effectively degraded and simultaneously removed. Reactive species identification tests including free radical quenching and EPR spectra were conducted. The results indicate that in addition to anodic direct oxidation, indirect oxidation by oxidative species (H2O2, â¢OH, and RCS) and flocculation by Al species also played a vital role in contaminant removal. Continuous-flow experiments show that Fe EC as a post-treatment step of Al 3DET could effectively provide a neutralization effect for the 3DET effluent and enhance the removal efficiency of contaminants. The total operating cost of combined process was 1.307 USD/m3. This study shows that the Al 3DET-Fe EC process is a promising technology for the treatment of nanofiltration concentrate.