Excitation of metal-free graphitic carbon nitride(g-C3N4) under visible light can successfully achieve efficient activation of peroxymonosulfate(PMS). Synergistic effects and involved mechanism were systematically inv...Excitation of metal-free graphitic carbon nitride(g-C3N4) under visible light can successfully achieve efficient activation of peroxymonosulfate(PMS). Synergistic effects and involved mechanism were systematically investigated using a light-inert endocrine disrupting compound, dimethyl phthalate(DMP), as the target pollutant. Under visible light irradiation, DMP could not be degraded by direct g-C3 N4-mediated photocatalysis, while in the presence of PMS, the dominant radicals were converted from ·O2 to SO4·– and ·OH, resulting in effective DMP degradation and mineralization. Results showed that higher dosage of PMS or g-C3 N4 could increase the activation amount of PMS and corresponding DMP degradation efficiency, but the latter approach was more productive in terms of making the most of PMS. High DMP concentration hindered effective contact between PMS and g-C3 N4, but could provide efficient use of PMS. Higher DMP degradation efficiency was achieved at p H lower than the point of zero charge(5.4). Based on intermediates identification, the DMP degradation was found mainly through radical attack(·OH and SO4·–) of the benzene ring and oxidation of the aliphatic chains.展开更多
Milk fat globule membrane(MFGM),which contains abundant glycoproteins and phospholipids,exerts beneficial effects on intestinal health and immunomodulation.The aim of this study was to evaluate the protective effects ...Milk fat globule membrane(MFGM),which contains abundant glycoproteins and phospholipids,exerts beneficial effects on intestinal health and immunomodulation.The aim of this study was to evaluate the protective effects and possible underlying mechanisms of MFGM on cow’s milk allergy(CMA)in aβ-lactoglobulin(BLG)-induced allergic mice model.MFGM was supplemented to allergic mice induced by BLG at a dose of 400 mg/kg body weight.Results demonstrated that MFGM alleviated food allergy symptoms,decreased serum levels of lipopolysaccharide,pro-inflammatory cytokines,immunoglobulin(Ig)E,Ig G1,and Th2 cytokines including interleukin(IL)-4,while increased serum levels of Th1 cytokines including interferon-γand regulatory T cells(Tregs)cytokines including IL-10 and transforming growth factor-β.MFGM modulated gut microbiota and enhanced intestinal barrier of BLG-allergic mice,as evidenced by decreased relative abundance of Desulfobacterota,Rikenellaceae,Lachnospiraceae,and Desulfovibrionaceae,while increased relative abundance of Bacteroidetes,Lactobacillaceae and Muribaculaceae,and enhanced expressions of tight junction proteins including Occludin,Claudin-1 and zonula occludens-1.Furthermore,MFGM increased fecal short-chain fatty acids(SCFAs)levels,which elevated G protein-coupled receptor(GPR)43 and GPR109A expressions.The increased expressions of GPR43 and GPR109A induced CD103+dendritic cells accumulation and promoted Tregs differentiation in mesenteric lymph node to a certain extent.In summary,MFGM alleviated CMA in a BLG-induced allergic mice model through enhancing intestinal barrier and promoting Tregs differentiation,which may be correlated with SCFAs-mediated activation of GPRs.These findings suggest that MFGM may be useful as a promising functional ingredient against CMA.展开更多
Camellia oil extracted from the seeds of Camellia oleifera Abel.is a popular and high-quality edible oil,but its yield is limited by seed setting,which is mainly caused by self-incompatibility(SI).One of the obvious b...Camellia oil extracted from the seeds of Camellia oleifera Abel.is a popular and high-quality edible oil,but its yield is limited by seed setting,which is mainly caused by self-incompatibility(SI).One of the obvious biological features of SI plants is the inhibition of self-pollen tubes;however,the underlying mechanism of this inhibition in C.oleifera is poorly understood.In this study,we constructed a semi-in vivo pollen tube growth test(SIV-PGT)system that can screen for substances that inhibit self-pollen tubes without interference from the genetic background.Combined with multi-omics analysis,the results revealed the important role of galloylated catechins in self-pollen tube inhibition,and a possible molecular regulatory network mediated by UDP-glycosyltransferase(UGT)and serine carboxypeptidase-like(SCPL)was proposed.In summary,galloylation of catechins and high levels of galloylated catechins are specifically involved in pollen tube inhibition under self-pollination rather than cross-pollination,which provides a new understanding of SI in C.oleifera.These results will contribute to sexual reproduction research on C.oleifera and provide theoretical support for improving Camellia oil yield in production.展开更多
The microbial communities colonized on microplastics(MPs)have attracted widespread attention.However,few studies focused on the MPs impacts on mangrove ecosystems,particularly on bacterial communities.We investigated ...The microbial communities colonized on microplastics(MPs)have attracted widespread attention.However,few studies focused on the MPs impacts on mangrove ecosystems,particularly on bacterial communities.We investigated the MPs pollution in mangrove of Zhujiang(Pearl)River estuary(ZRE).To study the potential risk posed by MPs to the mangrove ecosystems,the differences in bacterial communities,functions,and complexity between MPs and sediment samples were reported for the first time.Microplastics(2991±1586 items/kg dry weight(dw))in sediment were mainly fibers and polyethylene,mostly transparent,and in size less than 0.5 mm.Bacterial communities and functions significantly differed from MPs in mangrove sediment.Compared with sediment,MPs significantly enriched members of Proteobacteria,Bacteroidetes,and Actinobacteria,as well as the bacteria associated with plastic-degrading and human diseases on their surface,suggesting that microbial communities on MPs may promote MPs degradation and the spread of diseases,posing potential risk to mangrove ecosystems and human health.Although bacteria on MPs exhibited a lower diversity,the co-occurrence network analysis indicated that network of bacteria colonized on MPs was bigger and more complex than those of mangrove sediment,illustrating that MPs can act as a distinct habitat in this special ecosystem.This study provides a new perspective for increasing our understanding of microplastic pollution in mangrove ecosystems.展开更多
Food allergy has become a significant public health problem affecting a large number of people worldwide.Maternal obesity causes inflammation and alters the immune system of offspring,which may exacerbate their food a...Food allergy has become a significant public health problem affecting a large number of people worldwide.Maternal obesity causes inflammation and alters the immune system of offspring,which may exacerbate their food allergy.The aim of this study was to determine whether offspring mice born to obese mothers would have more serve reactions to cow's milk protein-induced food allergy,and further investigate the underlying mechanisms.Female offspring BALB/c mice of mothers with normal and high-fat diets were sensitized withβ-lactoglobulin(BLG),respectively.Maternal obesity increased the serum immunoglobulin E and mouse mast cell protease levels,though did not have significant influence on anaphylactic symptom score,core temperature and diarrhea rate of offspring mice after BLG sensitization.Furthermore,maternal obesity led to a lower level of occludin mRNA expression in BLG-sensitized mice.The mice born to obese mothers exhibited increased mRNA expression levels of GATA-3,interleukin(IL)-4 and IL-10 in jejunum after BLG sensitization,indicating maternal obesity intensified Th2-type biased immune responses.In conclusion,maternal obesity exerted exacerbating effects on the responsiveness of their offspring to cow's milk protein sensitization.展开更多
The tubulin-like protein FtsZ assembles into the Z ring that leads to the assembly and activation of the division machinery in most bacteria.ZapA,a widely conserved protein that interacts with FtsZ,plays a pivotal rol...The tubulin-like protein FtsZ assembles into the Z ring that leads to the assembly and activation of the division machinery in most bacteria.ZapA,a widely conserved protein that interacts with FtsZ,plays a pivotal role in organizing FtsZ filaments into a coherent Z ring.Previous studies revealed that ZapA forms a dumbbell-like tetramer that binds cooperatively to FtsZ filaments and aligns them in parallel,leading to the straightening and organization of FtsZ filament bundles.However,how ZapA interacts with FtsZ remains obscure.Here,we reveal that ZapA uses a two-pronged mechanism to interact with FtsZ to facilitate Z ring formation in Escherichia coli.We find that mutations affecting surface-exposed residues at the junction between adjacent FtsZ subunits in a filament as well as in an N-terminal motif of FtsZ weaken its interaction with ZapA in vivo and in vitro,indicating that ZapA binds to these regions of FtsZ.Consistent with this,ZapA prefers FtsZ polymers over monomeric FtsZ molecules and site-specific crosslinking confirmed that the dimer head domain of ZapA is in contact with the junction of FtsZ subunits.As a result,disruption of the putative interaction interfaces between FtsZ and ZapA abolishes the midcell localization of ZapA.Taken together,our results suggest that ZapA tetramers grab the N-terminal tails of FtsZ and bind to the junctions between FtsZ subunits in the filament to straighten and crosslink FtsZ filaments into the Z ring.展开更多
The combined analysis of dual diseases can provide new insights into pathogenic mechanisms,identify novel biomarkers,and develop targeted therapeutic strategies.Polycythemia vera(PV)is a chronic myeloproliferative neo...The combined analysis of dual diseases can provide new insights into pathogenic mechanisms,identify novel biomarkers,and develop targeted therapeutic strategies.Polycythemia vera(PV)is a chronic myeloproliferative neoplasm associated with a risk of acute myeloid leukemia(AML)transformation.However,the chronic nature of disease transformation complicates longitudinal high-throughput sequencing studies of patients with PV before and after AML transformation.This study aimed to develop a diagnostic model for malignant transformation of chronic proliferative diseases,addressing the challenges of early detection and intervention.Integrated public datasets of PV and AML were analyzed to identify differentially expressed genes(DEGs)and construct a weighted correlation network.Machine-learning algorithms screen genes for potential biomarkers,leading to the development of diagnostic models.Clinical specimens were collected to validate gene expression.cMAP and molecular docking predicted potential drugs.In vitro experiments were performed to assess drug efficacy in PV and AML cells.CIBERSORT and single-cell RNA-sequencing(scRNA-seq)analyses were used to explore the impact of hub genes on the tumor microenvironment.We identified 24 genes shared between PV and AML,which were enriched in immune-related pathways.Lactoferrin(LTF)and G protein-coupled receptor 65(GPR65)were integrated into a nomogram with a robust predictive power.The predicted drug vemurafenib inhibited proliferation and increased apoptosis in PV and AML cells.TME analysis has linked these biomarkers to macrophages.Clinical samples were used to confirm LTF and GPR65 expression levels.We identified shared genes between PV and AML and developed a diagnostic nomogram that offers a novel avenue for the diagnosis and clinical management of AML-related PV.展开更多
In this study,bismuth ferrite(BiFeO_(3),BFO)catalysts doped with different contents of peanut shell biochar(BC)were prepared and used in the removal of antibiotic-resistant bacteria(ARB)by peroxymonosulfate(PMS)activa...In this study,bismuth ferrite(BiFeO_(3),BFO)catalysts doped with different contents of peanut shell biochar(BC)were prepared and used in the removal of antibiotic-resistant bacteria(ARB)by peroxymonosulfate(PMS)activation from wastewater.The PMS(0.03 mM)/5%BC-BFO(0.5 g L^(−1))system removed 1.92 log ARB within 10 min of reaction at a reaction rate of 0.4401 min^(−1).Raman spectra analysis revealed that 5%BC-BFO exhibited more defects and oxygen vacancies(Ov),which provided active sites for PMS activation to generate SO_(4)^(⋅−),O_(2)^(⋅−),and^(1)O_(2),thereby promoting ARB inactivation.The oxidation of PMSO to PMSO₂suggests that high-valent iron-oxo species may also be involved in the inactivation of ARB.The PMS/5%BC-BFO system caused oxidative damage to the ARB cell membrane,increasing its permeability from 4.34%to 46.00%.Simultaneously,it triggered the activation of bacterial self-defense mechanisms and a cascade reaction,leading to the upregulation of intracellular reactive oxygen species(ROS)levels(rising from 6.34%to 62.90%),ultimately resulting in ARB inactivation.In addition,the ARB removal under PMS activation by the fourth recycled 5%BC-BFO catalyst was 62.6%of that by the fresh 5%BC-BFO.In summary,this study proposes a low-cost and easily synthesized novel catalyst for the efficient ARB removal from wastewater.展开更多
Metal-free photocatalysts have attracted growing concern recently.Herein,the composites combining g-C_(3)N_(4)with wood pulp cellulose biochar(WPBC/g-C_(3)N_(4))were synthesized to effectively activate peroxymonosulfa...Metal-free photocatalysts have attracted growing concern recently.Herein,the composites combining g-C_(3)N_(4)with wood pulp cellulose biochar(WPBC/g-C_(3)N_(4))were synthesized to effectively activate peroxymonosulfate(PMS)under visible light for the degradation of diclofenac(DCF).The incorporation of WPBC endowed g-C_(3)N_(4)with enhanced visible light absorption,improved charge separation capability,reduced electrical conductivity,and increased photocatalytic and PMS activation capability.Based on quenching tests,electron paramagnetic resonance(EPR),electrochemical analysis and solvent exchange experiments,both radical and nonradical mechanisms were proposed.Radical species including·OH,h^(+),·O_(2)^(-)were identified to contribute to DCF degradation.The 1O2 and electron transfer were the dominant nonradical pathways for DCF degradation.Moreover,the common influencing factors were examined,and DCF concentration was the most influential factor based on principal component analysis.Generally,the composites exhibited good reusability during consecutive runs.Based on HPLC/MS analysis,four intermediates were detected and the possible DCF degradation pathway was proposed.This work provided a potential strategy based on metal-free WPBC/g-C_(3)N_(4)for the photocatalytic activation of PMS to effectively degrade emerging contaminants in wastewater.展开更多
基金supported by the Natural Science Foundation of Jiangsu Province(BK20160936,BK20160938)the National Natural Science Foundation of China(51708297)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)~~
文摘Excitation of metal-free graphitic carbon nitride(g-C3N4) under visible light can successfully achieve efficient activation of peroxymonosulfate(PMS). Synergistic effects and involved mechanism were systematically investigated using a light-inert endocrine disrupting compound, dimethyl phthalate(DMP), as the target pollutant. Under visible light irradiation, DMP could not be degraded by direct g-C3 N4-mediated photocatalysis, while in the presence of PMS, the dominant radicals were converted from ·O2 to SO4·– and ·OH, resulting in effective DMP degradation and mineralization. Results showed that higher dosage of PMS or g-C3 N4 could increase the activation amount of PMS and corresponding DMP degradation efficiency, but the latter approach was more productive in terms of making the most of PMS. High DMP concentration hindered effective contact between PMS and g-C3 N4, but could provide efficient use of PMS. Higher DMP degradation efficiency was achieved at p H lower than the point of zero charge(5.4). Based on intermediates identification, the DMP degradation was found mainly through radical attack(·OH and SO4·–) of the benzene ring and oxidation of the aliphatic chains.
基金supported by the National Key Research and Development Program of China(Grant No.2019YFC1605000)National Natural Science Foundation of China(Grant No.31871806)the Beijing Livestock Industry Innovation Team(BAIC05-2023)。
文摘Milk fat globule membrane(MFGM),which contains abundant glycoproteins and phospholipids,exerts beneficial effects on intestinal health and immunomodulation.The aim of this study was to evaluate the protective effects and possible underlying mechanisms of MFGM on cow’s milk allergy(CMA)in aβ-lactoglobulin(BLG)-induced allergic mice model.MFGM was supplemented to allergic mice induced by BLG at a dose of 400 mg/kg body weight.Results demonstrated that MFGM alleviated food allergy symptoms,decreased serum levels of lipopolysaccharide,pro-inflammatory cytokines,immunoglobulin(Ig)E,Ig G1,and Th2 cytokines including interleukin(IL)-4,while increased serum levels of Th1 cytokines including interferon-γand regulatory T cells(Tregs)cytokines including IL-10 and transforming growth factor-β.MFGM modulated gut microbiota and enhanced intestinal barrier of BLG-allergic mice,as evidenced by decreased relative abundance of Desulfobacterota,Rikenellaceae,Lachnospiraceae,and Desulfovibrionaceae,while increased relative abundance of Bacteroidetes,Lactobacillaceae and Muribaculaceae,and enhanced expressions of tight junction proteins including Occludin,Claudin-1 and zonula occludens-1.Furthermore,MFGM increased fecal short-chain fatty acids(SCFAs)levels,which elevated G protein-coupled receptor(GPR)43 and GPR109A expressions.The increased expressions of GPR43 and GPR109A induced CD103+dendritic cells accumulation and promoted Tregs differentiation in mesenteric lymph node to a certain extent.In summary,MFGM alleviated CMA in a BLG-induced allergic mice model through enhancing intestinal barrier and promoting Tregs differentiation,which may be correlated with SCFAs-mediated activation of GPRs.These findings suggest that MFGM may be useful as a promising functional ingredient against CMA.
基金Our work was supported by the National Key R&D Program of China(2018YFD1000603-1)the Natural Science Foundation of Hunan Province(2020JJ5968)+2 种基金Scientific Research Foundation for Advanced Talents of Central South University of Forestry and Technology(2018YJ002)Special Funds for the Construction of Innovative Provinces in Hunan(2021NK1007)the Key Program of Education Department of Hunan Province(grant no.20A524).
文摘Camellia oil extracted from the seeds of Camellia oleifera Abel.is a popular and high-quality edible oil,but its yield is limited by seed setting,which is mainly caused by self-incompatibility(SI).One of the obvious biological features of SI plants is the inhibition of self-pollen tubes;however,the underlying mechanism of this inhibition in C.oleifera is poorly understood.In this study,we constructed a semi-in vivo pollen tube growth test(SIV-PGT)system that can screen for substances that inhibit self-pollen tubes without interference from the genetic background.Combined with multi-omics analysis,the results revealed the important role of galloylated catechins in self-pollen tube inhibition,and a possible molecular regulatory network mediated by UDP-glycosyltransferase(UGT)and serine carboxypeptidase-like(SCPL)was proposed.In summary,galloylation of catechins and high levels of galloylated catechins are specifically involved in pollen tube inhibition under self-pollination rather than cross-pollination,which provides a new understanding of SI in C.oleifera.These results will contribute to sexual reproduction research on C.oleifera and provide theoretical support for improving Camellia oil yield in production.
基金Supported by the National Natural Science Foundation of China(Nos.42177253,41807476,41706186)Natural Science Foundation of Guangdong Province,China(No.2022A1515010197)。
文摘The microbial communities colonized on microplastics(MPs)have attracted widespread attention.However,few studies focused on the MPs impacts on mangrove ecosystems,particularly on bacterial communities.We investigated the MPs pollution in mangrove of Zhujiang(Pearl)River estuary(ZRE).To study the potential risk posed by MPs to the mangrove ecosystems,the differences in bacterial communities,functions,and complexity between MPs and sediment samples were reported for the first time.Microplastics(2991±1586 items/kg dry weight(dw))in sediment were mainly fibers and polyethylene,mostly transparent,and in size less than 0.5 mm.Bacterial communities and functions significantly differed from MPs in mangrove sediment.Compared with sediment,MPs significantly enriched members of Proteobacteria,Bacteroidetes,and Actinobacteria,as well as the bacteria associated with plastic-degrading and human diseases on their surface,suggesting that microbial communities on MPs may promote MPs degradation and the spread of diseases,posing potential risk to mangrove ecosystems and human health.Although bacteria on MPs exhibited a lower diversity,the co-occurrence network analysis indicated that network of bacteria colonized on MPs was bigger and more complex than those of mangrove sediment,illustrating that MPs can act as a distinct habitat in this special ecosystem.This study provides a new perspective for increasing our understanding of microplastic pollution in mangrove ecosystems.
基金supported by the National Key Research and Development Program of China(2019YFC1605000)the Beijing Dairy Industry Innovation Team(BAIC06-2021)。
文摘Food allergy has become a significant public health problem affecting a large number of people worldwide.Maternal obesity causes inflammation and alters the immune system of offspring,which may exacerbate their food allergy.The aim of this study was to determine whether offspring mice born to obese mothers would have more serve reactions to cow's milk protein-induced food allergy,and further investigate the underlying mechanisms.Female offspring BALB/c mice of mothers with normal and high-fat diets were sensitized withβ-lactoglobulin(BLG),respectively.Maternal obesity increased the serum immunoglobulin E and mouse mast cell protease levels,though did not have significant influence on anaphylactic symptom score,core temperature and diarrhea rate of offspring mice after BLG sensitization.Furthermore,maternal obesity led to a lower level of occludin mRNA expression in BLG-sensitized mice.The mice born to obese mothers exhibited increased mRNA expression levels of GATA-3,interleukin(IL)-4 and IL-10 in jejunum after BLG sensitization,indicating maternal obesity intensified Th2-type biased immune responses.In conclusion,maternal obesity exerted exacerbating effects on the responsiveness of their offspring to cow's milk protein sensitization.
基金supported by the National Natural Science Foundation of China(grant Nos.32070032 and 32270049)the Fundamental Research Funds for the Central Universities(grant No.2042021kf0198)+3 种基金the Young Top-notch Talent Cultivation Program of China to S.D.S.H.'s research is supported by the National Natural Science Foundation of China(grant Nos.32161133002 and 62072199)D.Y.,X.W.,H.H.,and X.Y.'s research is supported by the National Natural Science Foundation of China(grant No.32270035)the Anhui Provincial Natural Science Foundation(Award No.2208085MC40).
文摘The tubulin-like protein FtsZ assembles into the Z ring that leads to the assembly and activation of the division machinery in most bacteria.ZapA,a widely conserved protein that interacts with FtsZ,plays a pivotal role in organizing FtsZ filaments into a coherent Z ring.Previous studies revealed that ZapA forms a dumbbell-like tetramer that binds cooperatively to FtsZ filaments and aligns them in parallel,leading to the straightening and organization of FtsZ filament bundles.However,how ZapA interacts with FtsZ remains obscure.Here,we reveal that ZapA uses a two-pronged mechanism to interact with FtsZ to facilitate Z ring formation in Escherichia coli.We find that mutations affecting surface-exposed residues at the junction between adjacent FtsZ subunits in a filament as well as in an N-terminal motif of FtsZ weaken its interaction with ZapA in vivo and in vitro,indicating that ZapA binds to these regions of FtsZ.Consistent with this,ZapA prefers FtsZ polymers over monomeric FtsZ molecules and site-specific crosslinking confirmed that the dimer head domain of ZapA is in contact with the junction of FtsZ subunits.As a result,disruption of the putative interaction interfaces between FtsZ and ZapA abolishes the midcell localization of ZapA.Taken together,our results suggest that ZapA tetramers grab the N-terminal tails of FtsZ and bind to the junctions between FtsZ subunits in the filament to straighten and crosslink FtsZ filaments into the Z ring.
基金supported by grants from the National Natural Science Foundation of China(Grant numbers 81920108004,82270127,and 81800125)the grants from Shenzhen Health Development Research and Data Management Center(Grant number sz20230199 and 0868-2344ZD1274F)+1 种基金the Hunan Provincial Natural Science Foundation(Grant numbers 2024JJ3037,2023JJ30928,and 2025JJ60692)the Changsha Science and Technology Bureau(Grant number kq2208382).
文摘The combined analysis of dual diseases can provide new insights into pathogenic mechanisms,identify novel biomarkers,and develop targeted therapeutic strategies.Polycythemia vera(PV)is a chronic myeloproliferative neoplasm associated with a risk of acute myeloid leukemia(AML)transformation.However,the chronic nature of disease transformation complicates longitudinal high-throughput sequencing studies of patients with PV before and after AML transformation.This study aimed to develop a diagnostic model for malignant transformation of chronic proliferative diseases,addressing the challenges of early detection and intervention.Integrated public datasets of PV and AML were analyzed to identify differentially expressed genes(DEGs)and construct a weighted correlation network.Machine-learning algorithms screen genes for potential biomarkers,leading to the development of diagnostic models.Clinical specimens were collected to validate gene expression.cMAP and molecular docking predicted potential drugs.In vitro experiments were performed to assess drug efficacy in PV and AML cells.CIBERSORT and single-cell RNA-sequencing(scRNA-seq)analyses were used to explore the impact of hub genes on the tumor microenvironment.We identified 24 genes shared between PV and AML,which were enriched in immune-related pathways.Lactoferrin(LTF)and G protein-coupled receptor 65(GPR65)were integrated into a nomogram with a robust predictive power.The predicted drug vemurafenib inhibited proliferation and increased apoptosis in PV and AML cells.TME analysis has linked these biomarkers to macrophages.Clinical samples were used to confirm LTF and GPR65 expression levels.We identified shared genes between PV and AML and developed a diagnostic nomogram that offers a novel avenue for the diagnosis and clinical management of AML-related PV.
基金supported by Guangdong Basic and Applied Basic Research Foundation(2024A1515030201,2022A1515010197)the National Natural Science Foundation of China(41807476,42377363,42177253)Guangzhou Science and Technology Project of China(Basic and Applied Basic Research project)(202102020892).
文摘In this study,bismuth ferrite(BiFeO_(3),BFO)catalysts doped with different contents of peanut shell biochar(BC)were prepared and used in the removal of antibiotic-resistant bacteria(ARB)by peroxymonosulfate(PMS)activation from wastewater.The PMS(0.03 mM)/5%BC-BFO(0.5 g L^(−1))system removed 1.92 log ARB within 10 min of reaction at a reaction rate of 0.4401 min^(−1).Raman spectra analysis revealed that 5%BC-BFO exhibited more defects and oxygen vacancies(Ov),which provided active sites for PMS activation to generate SO_(4)^(⋅−),O_(2)^(⋅−),and^(1)O_(2),thereby promoting ARB inactivation.The oxidation of PMSO to PMSO₂suggests that high-valent iron-oxo species may also be involved in the inactivation of ARB.The PMS/5%BC-BFO system caused oxidative damage to the ARB cell membrane,increasing its permeability from 4.34%to 46.00%.Simultaneously,it triggered the activation of bacterial self-defense mechanisms and a cascade reaction,leading to the upregulation of intracellular reactive oxygen species(ROS)levels(rising from 6.34%to 62.90%),ultimately resulting in ARB inactivation.In addition,the ARB removal under PMS activation by the fourth recycled 5%BC-BFO catalyst was 62.6%of that by the fresh 5%BC-BFO.In summary,this study proposes a low-cost and easily synthesized novel catalyst for the efficient ARB removal from wastewater.
基金China Postdoctoral Science Foundation(Grant No.2019 M661856)Qing Lan Project of Jiangsu Province(Grant No.2020)+2 种基金Natural Science Foundation of Jiangsu Province,China(Grant No.BK20201385)National Key Research and Development Project(Grant No.2017YFC0505803)National Natural Science Foundation of China(NSFC)(Grant No.41977354).
文摘Metal-free photocatalysts have attracted growing concern recently.Herein,the composites combining g-C_(3)N_(4)with wood pulp cellulose biochar(WPBC/g-C_(3)N_(4))were synthesized to effectively activate peroxymonosulfate(PMS)under visible light for the degradation of diclofenac(DCF).The incorporation of WPBC endowed g-C_(3)N_(4)with enhanced visible light absorption,improved charge separation capability,reduced electrical conductivity,and increased photocatalytic and PMS activation capability.Based on quenching tests,electron paramagnetic resonance(EPR),electrochemical analysis and solvent exchange experiments,both radical and nonradical mechanisms were proposed.Radical species including·OH,h^(+),·O_(2)^(-)were identified to contribute to DCF degradation.The 1O2 and electron transfer were the dominant nonradical pathways for DCF degradation.Moreover,the common influencing factors were examined,and DCF concentration was the most influential factor based on principal component analysis.Generally,the composites exhibited good reusability during consecutive runs.Based on HPLC/MS analysis,four intermediates were detected and the possible DCF degradation pathway was proposed.This work provided a potential strategy based on metal-free WPBC/g-C_(3)N_(4)for the photocatalytic activation of PMS to effectively degrade emerging contaminants in wastewater.
