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1.
Small ; : e2312209, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38530091

RESUMO

Developing novel proton exchange membranes (PEMs) with low cost and superior performance to replace Nafion is of great significance. Polyoxometalate-doped sulfonated poly(aryl ether ketone sulfone) (SPAEKS) allows for the amalgamation of the advantages in each constituent, thereby achieving an optimized performance for the hybrid PEMs. Herein, the hybrid membranes by introducing 2MeIm-{Mo132} into SPAEKS are obtained. Excellent hydrophilic properties of 2MeIm-{Mo132} can help more water molecules be retained in the hybrid membrane, providing abundant carriers for proton transport and proton hopping sites to build successive hydrophilic channels, thus lowering the energy barrier, accelerating the proton migration, and significantly fostering the proton conductivity of hybrid membranes. Especially, SP-2MIMo132-5 exhibits an enhanced proton conductivity of 75 mS cm-1 at 80 °C, which is 82.9% higher than pristine SPAEKS membrane. Additionally, this membrane is suitable for application in proton exchange membrane fuel cells, and a maximum power density of 266.2 mW cm-2 can be achieved at 80 °C, which far exceeds that of pristine SPAEKS membrane (54.6 mW cm-2). This work demonstrates that polyoxometalate-based clusters can serve as excellent proton conduction sites, opening up the choice of proton conduction carriers in hybrid membrane design and providing a novel idea to manufacture high-performance PEMs.

2.
J Hazard Mater ; 469: 133984, 2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38460263

RESUMO

Light-stabilizing additives may contribute to the overall pollution load of microplastics (MPs) and potentially enter the food chain, severely threatening aquatic life and human health. This study investigated the variation between polystyrene (PS) MPs and phthalocyanine blue (CuPC)-containing MPs before and after photoaging, as well as their effects on Microcystis aeruginosa. The presence of PS-MPs increased cell mortality, antioxidant enzyme activity, and the variation in extracellular components, while the presence of CuPC exacerbated these variations. CuPC-containing MPs caused different increasing trends in superoxide dismutase and malondialdehyde activities due to electron transfer across the membrane. Transcriptomic analysis revealed that the MPs and CuPC affected various cellular processes, with the greatest impact being on cell membranes. Compared with MPs, CuPC negatively affected ribosome and polysaccharide formation. These findings provide insights into the molecular mechanisms underlying the cellular response to MPs and their associated light-stabilizer pollution and imply the necessity for mitigating the pollution of both MPs and light-stabilizers.


Assuntos
Cianobactérias , Indóis , Microcystis , Compostos Organometálicos , Poluentes Químicos da Água , Humanos , Microplásticos/toxicidade , Plásticos/toxicidade , Antioxidantes , Poliestirenos , Poluentes Químicos da Água/toxicidade
3.
Sci Total Environ ; 920: 170982, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38367723

RESUMO

The application of iron-doped biochar in peroxymonosulfate (PMS) activation systems has gained increasing attention due to their effectiveness and environmental friendliness in addressing environmental issues. However, the behavioral mechanism of iron doping and the detailed 1O2 generation mechanism in PMS activation systems remain ambiguous. Here, we investigated the effects of three anions (Cl-, NO3-and SO42-) on the process of iron doping into bone char, leading to the synthesis of three iron-doped bone char (Fe-ClBC, Fe-NBC and Fe -SBC). These iron-doped bone char were used to catalyze PMS to degrade acetaminophen (APAP) and exhibited the following activity order: Fe-ClBC > Fe-NBC > Fe-SBC. Characterization results indicated that iron doping primarily occurred through the substitution of calcium in hydroxyapatite within BC. In the course of the impregnation, the binding of SO42- and Ca2+ hindered the exchange of iron ions, resulting in lower catalytic activity of Fe-SBC. The primary reactive oxygen species in the Fe-ClBC/PMS and Fe-NBC/PMS systems were both 1O2. 1O2 is produced through O2•- conversion and PMS self-dissociation, which involves the generation of metastable iron intermediates and electron transfer within iron species. The presence of oxygen vacancies and more carbon defects in the Fe-ClBC catalyst facilitates 1O2 generation, thereby enhancing APAP degradation within the Fe-ClBC/PMS system. This study is dedicated to in-depth exploration of the mechanisms underlying iron doping and defect materials in promoting 1O2 generation.


Assuntos
Acetaminofen , Ferro , Suínos , Animais , Ferro/química , Peróxidos/química , Oxirredução , Oxigênio
4.
Environ Int ; 184: 108466, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38310816

RESUMO

The selective removal of targeted pollutants from complex wastewater is challenging. Herein, a novel persulfate (PS)-based advanced oxidation system equipped with a series of two-dimensional (2D) bimetallic oxide nanosheets (NSs) catalysts is developed to selectively degrade bisphenol A (BPA) within mixed pollutants via initiating nonradical-induced polymerization. Results indicate that the Ni0.60Co0.40Ox NSs demonstrate the highest catalytic efficiency among all Ni-Co NSs catalysts. Specifically, BPA degradation rate is 47.34, 27.26, and 9.72 times higher than that of 4-chlorophenol, phenol, and 2,4-dichlorophenol in the mixed solution, respectively. The lower oxidative potential of BPA in relation to the other pollutants renders it the primary target for oxidation within the PDS activation system. PDS molecules combine on the surface of Ni0.60Co0.40Ox NSs to form the surface-activated complex, triggering the generation of BPA monomer radicals through H-abstraction or electron transfer. These radicals subsequently polymerize on the surface of the catalyst through coupling reactions. Importantly, this polymerization process can occur under typical aquatic environmental conditions and demonstrates resistance to background matrices like Cl- and humic acid due to its inherent nonradical attributes. This study offers valuable insights into the targeted conversion of organic pollutants in wastewater into value-added polymers, contributing to carbon recycle and circular economy.


Assuntos
Compostos Benzidrílicos , Poluentes Ambientais , Poluentes Químicos da Água , Óxidos , Águas Residuárias , Oxirredução , Fenóis/análise
5.
Sci Total Environ ; 920: 170933, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38360324

RESUMO

As emerging contaminants, microplastics (MPs) are becoming a matter of global concern, and they have complex interactions with dissolved organic matter (DOM) widely present in aqueous environments. Here, we investigate the molecular interactions between aged polystyrene microplastics (PS-MPs) and fulvic acid (FA) under neutral conditions using a series of analytical techniques. The structural changes of FA and the binding interactions of PS-MPs with FA at a molecular level were explored by fluorescence and FT-IR combined with two-dimensional correlation spectroscopy (2D-COS). Results showed that photoaging of PS-MPs changed the sequence of structural variations with FA. Atomic force microscopy-infrared spectroscopy (AFM-IR) strongly demonstrated that the surface roughness of both pristine and aged PS-MPs greatly increased after FA addition. Meanwhile, AFM-IR and Raman spectroscopy revealed a stronger interaction between aged PS-MPs and FA. The content of oxygen-containing functional groups in PS-MPs increased after aging and after binding with FA, and surface distribution of these functional groups also changed. XPS analyses indicated that the oxygen content in PS-MPs increased after the interaction with FA and the increase in oxygen content was even greater in aged PS-MPs. Overall, these research findings are useful to understand the environmental impacts of DOM-MPs interactions and to address the uncertainty of MPs aging effect on their environmental behavior in aquatic ecosystems.

6.
J Microbiol Immunol Infect ; 57(2): 246-256, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38383245

RESUMO

BACKGROUND: Trichomonas vaginalis is parasitic protozoan that causes human urogenital infections. Accumulated reports indicated that exosomes released by this parasite play a crucial role in transmitting information and substances between cells during host-parasite interactions. Current knowledge on the protein contents in T. vaginalis exosome is mainly generated from three previous studies that used different T. vaginalis isolates as an experimental model. Whether T. vaginalis exosomes comprise a common set of proteins (core exosome proteome) is still unclear. METHODS: To explore the core exosome proteome in T. vaginalis, we used liquid chromatography-tandem mass spectrometry (LC-MS/MS) to identify the contents of sucrose ultracentrifugation-enriched exosome and supernatant fractions isolated from six isolates. RESULTS: Transmission electron microscopy (TEM) confirmed the presence of exosomes in the enriched fraction. Proteomic analysis identified a total of 1870 proteins from exosomal extracts. There were 1207 exosomal-specific proteins after excluding 436 'non-core exosomal proteins'. Among these, 72 common exosomal-specific proteins were expressed in all six isolates. Compared with three published T. vaginalis exosome proteome datasets, we identified 16 core exosomal-specific proteins. These core exosomal-specific proteins included tetraspanin (TvTSP1), the classical exosome marker, and proteins mainly involved in catalytic activity and binding such as ribosomal proteins, ras-associated binding (Rab) proteins, and heterotrimeric G proteins. CONCLUSIONS: Our study highlighted the importance of using supernatant fraction from exosomal extract as a control to eliminate 'non-core exosomal proteins'. We compiled a reference core exosome proteome of T. vaginalis, which is essential for developing a fundamental understanding of exosome-mediated cell communication and host-parasite interaction.


Assuntos
Exossomos , Trichomonas vaginalis , Humanos , Trichomonas vaginalis/metabolismo , Proteoma/análise , Exossomos/química , Exossomos/metabolismo , Proteômica , Cromatografia Líquida , Espectrometria de Massas em Tandem
7.
Sci Total Environ ; 912: 168833, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38036120

RESUMO

Bone char is a functional material obtained by calcining animal bones and is widely used for environmental remediation. In this work, iron was inserted into porcine bone-derived bone char via ion exchange to synthesize iron-doped bone char (Fe-BC) for efficient catalysis of hydrogen peroxide. This is the first time that Fe-BC has been used as a catalyst for the activation of H2O2. The effectiveness of the Fe-BC catalyst was influenced by the annealing temperature and the amount of iron doping. The results showed that the activation of H2O2 by the Fe-BC catalyst with the best catalytic performance could achieve 97.6% of APAP degradation within 30 min. Insights from electron paramagnetic resonance (EPR), free radical scavenging experiments and linear sweep voltammetry (LSV) proposed a reaction mechanism based on free radicals dominated degradation pathways (OH and O2-). Iron served as the primary active site in Fe-BC, with defect sites and oxygen-containing groups in the catalyst also contributing to the removal of pollutants. The Fe-BC/H2O2 system demonstrated resilience to interference from common anions (Cl-, NO3-, SO42- and HCO3-) in water, but was less effective against humic acid (HA). Based on the detection of intermediates produced during APAP degradation, possible degradation pathways of APAP were proposed and the toxicity of intermediates was evaluated. This work provides fresh insights into the use of heterogeneous Fenton catalysts for the removal of organic pollutants from water.


Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Animais , Suínos , Peróxido de Hidrogênio/química , Ferro/química , Acetaminofen , Água , Oxigênio , Poluentes Químicos da Água/análise , Catálise , Oxirredução
8.
Sci Total Environ ; 913: 169623, 2024 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-38159742

RESUMO

Infrared (IR) spectroscopy is a powerful technique for detecting and identifying Microplastics (MPs) in the environment. However, the aging of MPs presents a challenge in accurately identification and classification. To address this challenge, a classification model based on deep convolutional neural networks (CNNs) was developed using infrared spectra results. Particularly, original infrared (IR) spectra were used as the sample dataset, therefore, relevant spectral details were preserved and additional noise or distortions were not introduced. The Adam (Adaptive moment estimation) algorithm was employed to accelerate gradient descent and weight update, the Dropout function was implemented to prevent overfitting and enhance the generalization performance of the network. An activation function ReLu (Rectified Linear Unit) was also utilized to simplify the co-adaptation relationship among neurons and prevent gradient disappearance. The performance of the CNN model in MPs classification was evaluated based on accuracy and robustness, and compared with other machine learning techniques. CNN model demonstrated superior capabilities in feature extraction and recognition, and greatly simplified the pre-processing procedure. The identification results of aged commercial microplastic samples showed accuracies of 40 % for Artificial Neural Network, 60 % for Random Forest, 80 % for Deep Neural Network, and 100 % for CNN, respectively. The CNN architecture developed in this work also demonstrates versatility by being suitable for both limited data cases and potential expansion to include more discrete data in the future.

9.
Hum Genet ; 2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37758909

RESUMO

Nonmutational epigenetic reprogramming is a crucial mechanism contributing to the pronounced heterogeneity of prostate cancer (PCa). Among these mechanisms, N6-methyladenosine (m6A)-modified long non-coding RNAs (lncRNAs) have emerged as key players. However, the precise roles of m6A-modified lncRNAs in PCa remain to be elucidated. In this study, methylated RNA immunoprecipitation sequencing (MeRIP-seq) was conducted on primary and metastatic PCa samples, leading to the identification of 21 lncRNAs exhibiting differential methylation and expression patterns. We further established a PCa prognostic signature, named m6A-modified lncRNA score (mLs), based on 9 differential methylated lncRNAs in 4 multicenter cohorts. The high mLs score cohort exhibited a tendency for earlier biochemical recurrence (BCR) compared to the low mLs score cohort. Remarkably, the predictive performance of the mLs score surpassed that of five previously reported lncRNA-based signatures. Functional enrichment analysis underscored a negative correlation between the mLs score and lipid metabolism. Additionally, through MeRIP-qPCR, we pinpointed a hub gene, MIR210HG, which was validated through in vitro and in vivo experiments. These findings collectively illuminate the landscape of m6A-methylated lncRNAs in PCa tissue via MeRIP-seq and harness this information to prognosticate PCa outcomes using the mLs score. Furthermore, our study validates, both experimentally and mechanistically, the facilitative role of MIR210HG in driving PCa progression.

10.
Sci Total Environ ; 899: 165615, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37481081

RESUMO

Microplastics (MPs) in the environment are a major global concern due to their persistent nature and wide distribution. The aging of MPs is influenced by several processes including photodegradation, thermal degradation, biodegradation and mechanical fragmentation, which affect their interaction with contaminants. This comprehensive review aims to summarize the aging process of MPs and the factors that impact their aging, and to discuss the effects of aging on the interaction of MPs with contaminants. A range of characterization methods that can effectively elucidate the mechanistic processes of these interactions are outlined. The rate and extent of MPs aging are influenced by their physicochemical properties and other environmental factors, which ultimately affect the adsorption and aggregation of aged MPs with environmental contaminants. Pollutants such as heavy metals, organic matter and microorganisms have a tendency to accumulate on MPs through adsorption and the interactions between them impact their environmental behavior. Aging enhances the specific surface area and oxygen-containing functional groups of MPs, thereby affecting the mechanism of interaction between MPs and contaminants. To obtain a more comprehensive understanding of how aging affects the interactions, this review also provides an overview of the mechanisms by which MPs interact with contaminants. In the future, there should be further in-depth studies of the potential hazards of aged MPs in different environments e.g., soil, sediment, aquatic environment, and effects of their interaction with environmental pollutants on human health and ecology.


Assuntos
Poluentes Ambientais , Microplásticos , Humanos , Idoso , Microplásticos/toxicidade , Plásticos , Adsorção , Envelhecimento , Biodegradação Ambiental
11.
Front Oncol ; 13: 999193, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37274263

RESUMO

Background: Colon cancer is one of the common cancers, and its prognosis remains to be improved. The role of cuproptosis as a newly discovered form of cell death in the development of colon cancer has not been determined. Methods: Based on 983 colon cancer samples in the TCGA database and the GEO database, we performed a comprehensive genomic analysis to explore the molecular subtypes mediated by cuproptosis-related genes. Single-sample gene set enrichment analysis (ssGSEA) was utilized to quantify the relative abundance of each cell infiltrate in the TME. A risk score was established using least absolute shrinkage and selection operator regression (LASSO), and its predictive ability for colon cancer patients was verified to explore its guiding value for treatment. Results: We identified two distinct cuproptosis-related molecular subtypes in colon cancer. These two distinct molecular subtypes can predict clinicopathological features, prognosis, TME activity, and immune-infiltrating cells. A risk model was developed and its predictive ability was verified. Compared with patients in the high-risk score group, patients in the low-risk score group were characterized by lower tumor microenvironment score, higher stem cell activity, lower tumor mutational burden, lower microsatellite instability, higher sensitivity to chemotherapeutics, and better immunotherapy efficacy. Conclusion: This study contributes to understanding the molecular characteristics of cuproptosis-related subtypes. We demonstrate a critical role for cuproptosis genes in colon cancer s in the TME. Our study contributes to the development of individualized treatment regimens for colon cancer.

12.
Chemosphere ; 326: 138471, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36963158

RESUMO

The activity of iron-based catalysts in advanced oxidation processes (AOPs) is limited by the redox cycle of Fe(III) and Fe(II). In this work, iron oxychloride (FeOCl) with a unique layered structure was loaded on the bone char (BC) to enhance the activation of peroxymonosulfate (PMS). Characterization of the FeOCl-BC catalyst reveals that the loading of FeOCl changed the composition and structure of BC and BC reduced the bond gap of FeOCl. Acetaminophen (APAP) as a target pollutant could be almost completely degraded at neutral pH, and the removal rate reached 0.6597 min-1. APAP could also be selectively oxidized by FeOCl-BC/PMS system in the presence of some inorganic anions (SO42-, NO3-, and Cl-) and humic acid. Quenching experiments, electron paramagnetic resonance (EPR), chemical probes, and linear sweep voltammetry (LSV) confirm that the primary oxidation mechanism of the FeOCl-BC/PMS system was dominated by 1O2. The 1O2 was generated from the conversion of O2•- and the self-dissociation of PMS, involving the formation of metastable iron intermediates and the redox cycle of Fe(III) and Fe(II). The unique structure of FeOCl, the transport of lattice oxygen and the enrichment of electrons by carbon defects play an essential role in generating reactive species. In this work, the limitation of the redox cycle of Fe(III) and Fe(II) was broken by loading FeOCl on the surface of BC, and a new catalytic mechanism was proposed. This work provides a new perspective for the construction of efficient iron-based catalysts and the practical application of PMS-based AOPs.


Assuntos
Poluentes Ambientais , Oxigênio Singlete , Compostos Férricos , Acetaminofen , Poluentes Ambientais/química , Peróxidos/química , Ferro/química , Compostos Ferrosos
13.
Sci Total Environ ; 871: 162151, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-36764556

RESUMO

The most important factor that restricts the decomposition of H2O2 in the Fe3+/H2O2 reaction is the slow cycling efficiency of reducing Fe3+ to Fe2+. In this study, the addition of tungsten disulfide (WS2) as a co-catalyst achieved a rapid cycling of the reaction rate-limiting step and a significant enhancement of H2O2 decomposition, which resulted in the effective degradation of acetaminophen (APAP). Results show that 99.6% of APAP (5 mg L-1) could be degraded by H2O2/Fe3+/WS2 system within 2.5 min. The conversion of Fe3+ to Fe2+ occurred mainly on the surface of WS2 due to the redox reaction of the exposed W4+ active sites with Fe3+ after the unsaturated S atoms were bound to protons. Electron paramagnetic resonance (EPR) and radical quenching experiments evaluated the contribution of hydroxyl radical (•OH) and superoxide radical (O2•-) in the degradation of pollutants. WS2 showed good recoverability after four cycles of the reaction. This study provides a new perspective to improve the efficiency of Fe3+/H2O2 and provides a reference for the involvement of transition metal sulfides in advanced oxidation processes (AOPs).

14.
Chemosphere ; 320: 137820, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36736841

RESUMO

Microplastics (MPs), antibiotics and microorganism ubiquitously coexist in aquatic environments. MPs inevitably undergo photoaging processes in aquatic environments, affecting the interactions between MPs and antibiotics and the antibiotic resistance of microorganism. In this study, the impact of photoaging processes of MPs on their adsorption behavior of tetracycline (TC) and related formation of antibiotic resistance were investigated. It was found that the photoaging processes significantly increased the adsorption capacity of TC onto MPs, with the Qe increasing from 0.387 to 0.507 mg/g at 288 K and from 0.507 to 0.688 mg/g at 308 K. The site energy distribution (SED) analysis further confirmed that the enhanced adsorption capacity was attributed to more high-energy adsorption sites acquired from MPs photoaging processes. Moreover, the enhanced adsorption of TC further facilitated the formation of seven antibiotic resistance genes (i.e., tetA, tetB, tetC, tetD, tetE, tetG, tetK) when MPs adsorbed with TC was covered by biofilm. This study helps comprehensively understand the environmental behaviors of co-existing MPs, antibiotics and microorganisms, providing a theoretical basis for evaluating and mitigating their coexistence risks.


Assuntos
Compostos Heterocíclicos , Envelhecimento da Pele , Poluentes Químicos da Água , Microplásticos , Plásticos , Cloreto de Polivinila , Adsorção , Tetraciclina , Antibacterianos , Resistência Microbiana a Medicamentos , Poluentes Químicos da Água/análise
15.
Sci Total Environ ; 868: 161533, 2023 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-36640880

RESUMO

Hydroxyl radicals (•OH) are the most active, aggressive and oxidative reactive oxygen species. In the natural aquatic environment, •OH plays an important role in the biogeochemistry cycle, biotransformation, and pollution removal. This paper reviewed the distribution and formation mechanism of •OH in aquatic environments, including natural waters, colloidal substances, sediments, and organisms. Furthermore, factors affecting the formation and consumption of •OH were thoroughly discussed, and the mechanisms of •OH generation and scavenging were summarized. In particular, the effects of climate change and artificial work on •OH in the largest natural aquatic environment, i.e., marine environment was analyzed with the help of bibliometrics. Moreover, Fenton reactions make the •OH variation more complicated and should not be neglected, especially in those areas with suspended particles and sediments. Regarding the •OH variation in the natural aquatic environment, more attention should be given to global change and human activities.

16.
Sci Total Environ ; 871: 161826, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-36708820

RESUMO

Natural iron-bearing minerals are widely distributed in the environment and show prominent catalytic performance in pollutant removal. This work provides an overview of groundwater restoration technologies utilizing heterogeneous electro-Fenton (HEF) techniques with the aid of different iron forms as catalysts. In particular, applications of natural iron-bearing minerals in groundwater in the HEF system have been thoroughly summarized from either the view of organic pollutant removal or degradation. Based on the analysis of the catalytic mechanism in the HEF process by pyrite (FeS2), goethite (α-FeOOH), and magnetite (Fe3O4) and the geochemistry analysis of these natural iron-bearing minerals in groundwater, the feasibility and challenges of HEF for organic degradation by using typical iron minerals in groundwater have been discussed, and natural factors affecting the HEF process have been analyzed so that appropriate in situ remedial measures can be applied to contaminated groundwater.

17.
Sci Total Environ ; 849: 157951, 2022 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-35961392

RESUMO

Microplastics (MPs), an emerging pollutant, are of global concern due to their wide distribution and large quantities. In addition to MPs themselves, various additives within MPs (such as plasticizers, flame retardants, antioxidants and heavy metals) may also have harmful effects on the environment. Most of these additives are physically bound to plastics and can therefore be leached from the plastic and released into the environment. Aging of MPs in the actual environment can affect the migration and release of additives, further increasing the ecotoxicological risk of additives to organisms. This work reviews the functions of several commonly used additives in MPs, and summarizes the representative characterization methods. Furthermore, the migration and leaching of additives in the human environment and marine environment are outlined. As aging promotes the internal chain breaking of MPs and the increase of specific surface area, it in turn stimulates the release of additives. The hazards of additive exposure have been elucidated, and various studies from the laboratory have shown that more toxic additives such as phthalates and brominated flame retardants can disrupt a variety of biological processes in organisms, including metabolism, skeletal development and so on. Increase of MPs ecological risk caused by the leaching of toxic additives is discussed, especially under the effect of aging. This study presents a systematic summary of various functional and environmental behaviors of additives in plastics, using weathering forces as the main factor, which helps to better assess the environmental impact and potential risks of MPs.


Assuntos
Poluentes Ambientais , Retardadores de Chama , Metais Pesados , Poluentes Químicos da Água , Envelhecimento , Antioxidantes , Poluentes Ambientais/toxicidade , Retardadores de Chama/toxicidade , Humanos , Microplásticos , Plastificantes/toxicidade , Plásticos/toxicidade , Poluentes Químicos da Água/análise
18.
Water Res ; 222: 118921, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35932707

RESUMO

As an emerging pollutant, microplastics (MPs) may interact with dissolved organic matter (DOM) which is prevalent in the aqueous environment. Meanwhile, the aging of MPs in the actual environment increases the uncertainty of their environmental fate. Here, the interaction mechanisms between pristine and aged polypropylene microplastics (PP-MPs) and humic acid (HA) at pH 7.0 were explored. Microstructural changes of HA were examined by fluorescence and Fourier transformation infrared (FT-IR) spectroscopy. Atomic force microscopy coupled with infrared (AFM-IR) and micro-Raman techniques were used to characterize and analyze the interacted PP-MPs. The addition of HA increased the surface roughness of both pristine and aged PP-MPs. Results of AFM-IR and Raman spectra showed that the interaction of PP-MPs with HA accelerated their surface oxidation and enhanced the characteristic signals. XPS spectra showed that the oxygen content ratio of pristine and aged PP-MPs increased by 0.95% and 1.48% after the addition of HA, respectively. PP-MPs after aging interacted more strongly with HA and there was a higher affinity between them. Two-dimensional correlation spectroscopy (2D-COS) combined with FT-IR spectra further elucidated the interaction mechanism at the molecular level. This work will help to evaluate the environmental impact of MPs in ecosystems and understand their interactions with DOM.


Assuntos
Microplásticos , Poluentes Químicos da Água , Ecossistema , Substâncias Húmicas/análise , Plásticos/química , Polipropilenos , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/química
19.
Sci Total Environ ; 851(Pt 1): 157948, 2022 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-35963400

RESUMO

Traditionally, toxicity of microplastics is ascribed to the chemicals adsorbed on them. However, microplastics can also interact with biomolecules, such as secretory proteins from aquatic organisms, and form protein-coated microplastics corona complex with unknown toxic effects. Here, we investigated the toxic effects of polystyrene microplastics (PS) and bovine serum albumin (BSA) coated PS corona complex (PS + BSA) on adult zebrafish (Danio rerio) intestines. The food intake ratio, accumulation and distribution of microplastics, histopathological changes, and molecular effects related to the antioxidant system in the intestine were studied. For the first time, we observed that PS + BSA aggregated on the inner surface of the zebrafish intestine, whereas PS dispersed. The aggregation of PS + BSA resulted in increased microplastics accumulation and longer residence time in the zebrafish intestine, which inhibited food intake and generated reactive oxygen species (ROS) in the intestine. Furthermore, the functions of the Keap1-Nrf2-ARE antioxidant signaling pathway and the activation of antioxidant enzymes were significantly affected by PS + BSA after a 21-day exposure. Ultimately, a higher accumulation of ROS and stronger inhibition of antioxidants led to more severe intestinal injury. These results suggest that the increased toxicity of protein-coated microplastics corona complex may be affected by oxidative damage and can result in the inhibition of digestion due to their aggregation and longer residence time in the intestine. Therefore, the ecological risk of microplastics may be underestimated owing to the interactive mechanisms of microplastics and protein coronas.


Assuntos
Coroa de Proteína , Poluentes Químicos da Água , Animais , Antioxidantes , Proteína 1 Associada a ECH Semelhante a Kelch , Microplásticos/toxicidade , Fator 2 Relacionado a NF-E2 , Plásticos/toxicidade , Poliestirenos/toxicidade , Espécies Reativas de Oxigênio , Soroalbumina Bovina , Poluentes Químicos da Água/toxicidade , Peixe-Zebra
20.
Front Microbiol ; 13: 893692, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35602021

RESUMO

Trichomonas vaginalis is a parasitic protist that infects the human urogenital tract. During the infection, trichomonads adhere to the host mucosa, acquire nutrients from the vaginal/prostate environment, and release small extracellular vesicles (sEVs) that contribute to the trichomonad adherence and modulate the host-parasite communication. Approximately 40-70% of T. vaginalis strains harbor a double-stranded RNA virus called Trichomonasvirus (TVV). Naked TVV particles have the potential to stimulate a proinflammatory response in human cells, however, the mode of TVV release from trichomonads to the environment is not clear. In this report, we showed for the first time that TVV particles are released from T. vaginalis cells within sEVs. The sEVs loaded with TVV stimulated a higher proinflammatory response of human HaCaT cells in comparison to sEVs from TVV negative parasites. Moreover, a comparison of T. vaginalis isogenic TVV plus and TVV minus clones revealed a significant impact of TVV infection on the sEV proteome and RNA cargo. Small EVs from TVV positive trichomonads contained 12 enriched and 8 unique proteins including membrane-associated BspA adhesine, and about a 2.5-fold increase in the content of small regulatory tsRNA. As T. vaginalis isolates are frequently infected with TVV, the release of TVV via sEVs to the environment represents an important factor with the potential to enhance inflammation-related pathogenesis during trichomoniasis.

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