In recent years,microplastics(MPs)in freshwater lake have been receiving increasing attention;however,the microbial communities on the surface of MPs have not been well studied.To investigate the potential risk posed ...In recent years,microplastics(MPs)in freshwater lake have been receiving increasing attention;however,the microbial communities on the surface of MPs have not been well studied.To investigate the potential risk posed by MPs to the lake ecosystem and its surface microbial community structure,MPs samples were collected in September 2023 in the freshwater Dongting Lake,Hunan,China,at five sites,and the differences in bacterial species community composition and structure between MPs and water samples were analyzed.Results show that MPs(13.71±3.32 items/L)in the samples were mostly black in color,fiber in shape,and PES in composition,and those<0.5 mm in size are dominant.The bacterial composition in water was different from that on MPs.At phylum level,Proteobacteria,Actinobacteria,Cyanobacteria,and Bacteroidetes were dominated in relative abundance in both water and MPs.Proteobacteria was more abundant in MPs than in water.The relative abundance of Bacteroidota and Actinobacteriota was significantly lower in MPs than in water.At genus level,Pantoea and Pseudomonas were potentially pathogenic genera in MPs surfaces.The presence of Cyanobacteria and pathogenic bacteria is undoubtedly a potential risk to the deterioration of the water quality.This study revealed the difference in the distribution of bacterial community in water and MPs in Dongting Lake and provided new perspectives to further understanding of MPs pollution in freshwater lakes.展开更多
Expanded polystyrene (EPS) is a common type of microplastics (MPs) often found in coastal areas especially aquaculture areas.It is considered as an important site for microbial colonization and biofilm formation,as we...Expanded polystyrene (EPS) is a common type of microplastics (MPs) often found in coastal areas especially aquaculture areas.It is considered as an important site for microbial colonization and biofilm formation,as well as a carrier of pollutants like heavy metals.However,the dynamic changes of bacterial communities attached to EPS and their interaction with heavy metals are still poorly unknown.In this study,a one-year field exposure experiment was conducted at an aquaculture farm near Donghai Island,in Leizhou Bay,Zhanjiang,Guangdong,in South China Sea.The bacterial communities attached to EPS MPs were examined by 16S r DNA high-throughput sequencing,and the relationships between bacterial biofilms and heavy metals were explored.The results show that there were notable seasonal variations in the bacterial diversity of EPS MPs.Species biodiversity was the highest in summer and the lowest in winter.The greatest number of bacterial species and lowest level of uniformity were observed in the spring.The bacterial community structure changed with exposure time,and the most significant difference in the 12-month group (P<0.05) was found.The dominant bacterial species attached to EPS MPs were mainly Proteobackteria and Firmicutes at the phylum level,and Pseudomonas and Exiguobacterium were dominant at the genus level.Furthermore,EPS MPs acted as transport carriers for potential pathogenic bacteria.High correlations were found between bacterial species and the total concentration of heavy metals on EPS MPs,as well as their speciation fractions.Different chemical speciation of heavy metals migrated and altered over seasons within biofilms,which would further exacerbate the ecological risks.展开更多
Microplastics(MPs),particularly polyvinyl chloride microplastics(PVC MPs)have become a notable environmental pollutant that affect various marine organisms such as Pinctada fucata martensii.As filter feeders,these biv...Microplastics(MPs),particularly polyvinyl chloride microplastics(PVC MPs)have become a notable environmental pollutant that affect various marine organisms such as Pinctada fucata martensii.As filter feeders,these bivalves consume significant volumes of water containing MPs,leading to contact with and ingestion of MPs.Moreover,given the ecological and economic importance of P.f.martensii in artificial pearl production,investigating the effects of PVC MPs exposure is crucial.This study aimed to investigate the effects of PVC MPs exposure on nucleus retention,pearl formation,oxidative stress by examining superoxide dismutase(SOD)activity,catalase(CAT)activity,lipid peroxidation(LPO),and total antioxidant capacity(TAOC)of P.f.martensii,while also exploring transcriptomic changes at different concentrations and exposure time points,including a recovery period.The pearl oysters were exposed to PVC MPs at concentrations of 1-,2.5-,and 5-mg PVC MPs/L for 10 d followed by 6 d of recovery.After 1-,4-,10-d of exposure,and additional 6 d of recovery,samples were taken and analyzed.Findings revealed that only prolonged exposure(10 d)to PVC MPs affected SOD activity,while CAT activity,LPO,and TAOC remained unaffected throughout the experiment.Notably,SOD activity was restored during the 6-d recovery phase.Transcriptome analysis highlighted significant gene alterations linked to various pathways,affecting cellular processes,environmental information processing,genetic information processing,metabolism,and organismal systems,with an increase in pathway-related genes during recovery,implying a potential role of PVC MPs as gene inhibitors.This study provided insights into the effects of PVC MPs on P.f.martensii,shedding light on pearl retention,oxidative systems,and molecular pathways influenced by PVC MPs.Additionally,it contributed novel information on potential MPs exposure biomarkers,particularly relevant to marine organisms like P.f.martensii.展开更多
Penaeus vannamei, known as the whiteleg shrimp, holds significant economic importance in aquaculture. The intensive culture of P. vannamei poses substantial environmental risks, particularly in fragile ecosystems like...Penaeus vannamei, known as the whiteleg shrimp, holds significant economic importance in aquaculture. The intensive culture of P. vannamei poses substantial environmental risks, particularly in fragile ecosystems like estuarine mangroves. Although there is a consensus on the pollution and harmful effects of microplastics(MPs), study on the pollution and potential risks posed by P. vannamei in estuary mangroves remains scarce. Therefore, the extent of microplastic pollution was evaluated and the correlation between the properties of MPs and the potential risks they pose to P. vannamei was examined.The average MP abundance in P. vannamei from Jiulong River estuary was determined to be 0.46±0.03 n/g in five different polymers, i.e., polypropylene(PP), polyethylene(PE), polystyrene(PS), polyethylene terephthalate(PET), and polyvinyl chloride resin(PVC). The total percentage of PS, PE, and PET polymers was the greatest(73.85%), where PET and PP(26.16%) were highly correlated in size and shape. Small MPs(1-200 μm) come in irregular particles, fragments, films, and large-sized MPs(200-1 000 μm) were mainly foam-shaped. The hazard risk level of MPs in P. vannamei from Jiulong River estuary reached grade Ⅲ, and the overall hazard risk index(H) value was 593.66. Among all samples,PVC polymer accounted for the lowest proportion(5.52%), but the H value was as high as 582.42, which contributed 98.11% to the overall hazard risk index. Regardless of global or Chinese, the microplastic pollution of P. vannamei in the estuary is at a moderate level. The protocol for MPs characteristics and correlation in seafood should be the basis for the risk assessment framework. Further studies are needed to evaluate how the exposure to MPs poses a risk for human health.展开更多
Ingestion of microplastics by various organisms has been widely evidenced.Chemicals associated with microplastics(MPs)may be released to digestive tracts upon ingestion.However,the effect of aging and temperature on t...Ingestion of microplastics by various organisms has been widely evidenced.Chemicals associated with microplastics(MPs)may be released to digestive tracts upon ingestion.However,the effect of aging and temperature on the chemical desorption for MPs remains poorly understood.The exposure of polyethylene(PE)particles to UV radiation in dry air,tap water,and sea water was conducted to mimic the aging process of MPs in different environments.Polychlorinated biphenyls(PCBs),as a typical hydrophobic organic contaminant,were preloaded in these aged and pristine PE.The desorption was performed by exposing preloaded PE particles in simulated gastric and gut fluids at 25℃and 40℃.After UV aging,the average diameter of PE particles decreased rapidly with aging time,indicating continuously fragmentation of PE under UV exposure.The desorption of PCBs from PE particles under different conditions varied from 7%to 40%,and that from aged PE in gut fluid at 37℃was significantly higher than those under other conditions(P<0.05).Furthermore,a clear declining trend was observed as lg K_(ow)(octanol-water partition coefficient)value increased.The aging process,hydrophobicity of chemicals,and incubation temperature were important factors on the desorption of PCBs from PE.The present study helps understand the desorption of PCBs from microplastics and the potential risks of microplastics ingestion by organisms.展开更多
Glucocorticoids are widely utilized for treating various immune and inflammation-related diseases,prompting significant interest in their potential application for COVID-19 treatment.This study explored the efficacy a...Glucocorticoids are widely utilized for treating various immune and inflammation-related diseases,prompting significant interest in their potential application for COVID-19 treatment.This study explored the efficacy and safety of dexamethasone(DEX)and methylprednisolone(MP)in treating severe COVID-19.A cohort of 94 adult patients,aged 18 years and older,with severe COVID-19 was recruited.They received intravenous MP(40-80 mg/d)or DEX(5-10 mg/d)for 7-10 d.The primary objective was to assess the effects of these treatments on mortality rates.Additionally,the study aimed to compare the impact of these medications on various parameters,including the oxygenation index,inflammatory index,fungal infections,and hyperglycemia,serving as secondary endpoints.The findings revealed no fatalities in either group.However,there was one case of pulmonary fibrosis and Aspergillus fumigatus infection in the DEX group,and two cases of Aspergillus infection in the MP group.Although the differences were not statistically significant(P>0.05),the MP group showed a faster improvement in blood oxygen saturation compared to the DEX group,with a median time of 5 d vs 7 d.No statistically significant difference was observed between the two groups regarding improvement in C-reactive protein levels(P>0.05).Notably,DEX was associated with a higher incidence of hyperglycemia compared to MP(P<0.05).Both DEX and MP significantly reduced mortality rates among patients with severe COVID-19 and improved blood oxygen saturation and inflammatory markers.However,MP exhibited a more rapid onset of efficacy and fewer adverse reactions.展开更多
Microplastics(MPs)pollution has emerged as a critical global environmental issue,for which rivers serve as key conduits for the transport of MPs from land to ocean.There remained a lack of clarity regarding the charac...Microplastics(MPs)pollution has emerged as a critical global environmental issue,for which rivers serve as key conduits for the transport of MPs from land to ocean.There remained a lack of clarity regarding the characteristics and transport patterns of MPs pollution in diverse environmental media and seasons within a river basin.The Jiulong River basin in Fujian,southeast China was studied as case,whose spatial-temporal distribution,pollution characteristics,and transport dynamics of MPs in both surface water and groundwater were analyzed.Additionally,the features of MPs in different land use types during the dry season were examined.Results show that in wet season,the abundance of MPs in river water varied from 840 to 12300 p/m^(3),with an average of 3920 p/m^(3);in groundwater,the range was 740-1820 p/m^(3),averaging 1107 p/m^(3);and from 68 to 951 p/kg,with an average value of 265 p/kg in the soil(dry weight).In dry season,levels of MPs in river water ranged from 580 to 8880 p/m^(3),with an average of 4034 p/m^(3);groundwater exhibited a range of 860-14980 p/m^(3),averaging 3453 p/m^(3).Fibers consistently dominated the morphology of MPs,of which polyethylene terephthalate was identified as the predominant composition in each environmental medium.Our findings underscore the spatial and temporal variability in distribution and contamination characteristics of MPs across different media.Notably,MPs abundance in river water and groundwater exhibited a seasonal pattern,being higher in levels in dry season than in wet season.The downstream transport of MPs was facilitated by surface runoff,in which MPs in groundwater and surface water could complement to each other.Furthermore,population density and human activities were identified as influential factors on the distribution and abundance of MPs.This study revealed the order of magnitude of difference in annual estimates of MPs entering the sea among different models.Additionally,the interception volume by mangrove forest in the Jiulong River estuary was estimated approximately 1.51×10^(10)MPs particles per year.Ecological interception shall be considered when estimating the fluxes of MPs into the sea.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.52209048,52109083)the Hunan Provincial Natural Science Foundation(Nos.2024JJ5207,2021JJ40100)+1 种基金the Special Fund for Building Chenzhou National Sustainable Development Agenda Innovation Demonstration Zone in Hunan Province(No.2022sfq51)the China National University Student Innovation&Entrepreneurship Development Program(No.S202310536023)。
文摘In recent years,microplastics(MPs)in freshwater lake have been receiving increasing attention;however,the microbial communities on the surface of MPs have not been well studied.To investigate the potential risk posed by MPs to the lake ecosystem and its surface microbial community structure,MPs samples were collected in September 2023 in the freshwater Dongting Lake,Hunan,China,at five sites,and the differences in bacterial species community composition and structure between MPs and water samples were analyzed.Results show that MPs(13.71±3.32 items/L)in the samples were mostly black in color,fiber in shape,and PES in composition,and those<0.5 mm in size are dominant.The bacterial composition in water was different from that on MPs.At phylum level,Proteobacteria,Actinobacteria,Cyanobacteria,and Bacteroidetes were dominated in relative abundance in both water and MPs.Proteobacteria was more abundant in MPs than in water.The relative abundance of Bacteroidota and Actinobacteriota was significantly lower in MPs than in water.At genus level,Pantoea and Pseudomonas were potentially pathogenic genera in MPs surfaces.The presence of Cyanobacteria and pathogenic bacteria is undoubtedly a potential risk to the deterioration of the water quality.This study revealed the difference in the distribution of bacterial community in water and MPs in Dongting Lake and provided new perspectives to further understanding of MPs pollution in freshwater lakes.
基金Supported by the Hainan Province Science and Technology Special Fund (No.ZDYF2022SHFZ317)the Guangdong Province Key Laboratory of Applied Marine Biology (No.2023B1212060047)the Program for Scientific Research Start-up Funds of Guangdong Ocean University (No.060302332301)。
文摘Expanded polystyrene (EPS) is a common type of microplastics (MPs) often found in coastal areas especially aquaculture areas.It is considered as an important site for microbial colonization and biofilm formation,as well as a carrier of pollutants like heavy metals.However,the dynamic changes of bacterial communities attached to EPS and their interaction with heavy metals are still poorly unknown.In this study,a one-year field exposure experiment was conducted at an aquaculture farm near Donghai Island,in Leizhou Bay,Zhanjiang,Guangdong,in South China Sea.The bacterial communities attached to EPS MPs were examined by 16S r DNA high-throughput sequencing,and the relationships between bacterial biofilms and heavy metals were explored.The results show that there were notable seasonal variations in the bacterial diversity of EPS MPs.Species biodiversity was the highest in summer and the lowest in winter.The greatest number of bacterial species and lowest level of uniformity were observed in the spring.The bacterial community structure changed with exposure time,and the most significant difference in the 12-month group (P<0.05) was found.The dominant bacterial species attached to EPS MPs were mainly Proteobackteria and Firmicutes at the phylum level,and Pseudomonas and Exiguobacterium were dominant at the genus level.Furthermore,EPS MPs acted as transport carriers for potential pathogenic bacteria.High correlations were found between bacterial species and the total concentration of heavy metals on EPS MPs,as well as their speciation fractions.Different chemical speciation of heavy metals migrated and altered over seasons within biofilms,which would further exacerbate the ecological risks.
基金Supported by the Science and Technology Program of Guangdong Province(No.2022A1515010030)the National Natural Science Foundation of China(No.32102817)+3 种基金the Department of Education of Guangdong Province(Nos.2020ZDZX1045,2021KCXTD026)the earmarked fund for CARS-49,Students Innovation and Entrepreneurship Training Program(No.CXXL2022015)the Technology Program of Guangdong Zhanjiang(No.2022A01010)the Hengli Biosciences Excellence Project of Guangdong Ocean University(No.B23335-4)。
文摘Microplastics(MPs),particularly polyvinyl chloride microplastics(PVC MPs)have become a notable environmental pollutant that affect various marine organisms such as Pinctada fucata martensii.As filter feeders,these bivalves consume significant volumes of water containing MPs,leading to contact with and ingestion of MPs.Moreover,given the ecological and economic importance of P.f.martensii in artificial pearl production,investigating the effects of PVC MPs exposure is crucial.This study aimed to investigate the effects of PVC MPs exposure on nucleus retention,pearl formation,oxidative stress by examining superoxide dismutase(SOD)activity,catalase(CAT)activity,lipid peroxidation(LPO),and total antioxidant capacity(TAOC)of P.f.martensii,while also exploring transcriptomic changes at different concentrations and exposure time points,including a recovery period.The pearl oysters were exposed to PVC MPs at concentrations of 1-,2.5-,and 5-mg PVC MPs/L for 10 d followed by 6 d of recovery.After 1-,4-,10-d of exposure,and additional 6 d of recovery,samples were taken and analyzed.Findings revealed that only prolonged exposure(10 d)to PVC MPs affected SOD activity,while CAT activity,LPO,and TAOC remained unaffected throughout the experiment.Notably,SOD activity was restored during the 6-d recovery phase.Transcriptome analysis highlighted significant gene alterations linked to various pathways,affecting cellular processes,environmental information processing,genetic information processing,metabolism,and organismal systems,with an increase in pathway-related genes during recovery,implying a potential role of PVC MPs as gene inhibitors.This study provided insights into the effects of PVC MPs on P.f.martensii,shedding light on pearl retention,oxidative systems,and molecular pathways influenced by PVC MPs.Additionally,it contributed novel information on potential MPs exposure biomarkers,particularly relevant to marine organisms like P.f.martensii.
基金Supported by the Natural Science Foundation of Xiamen (No. 3502Z20227322)the Natural Science Key Foundation of Fujian Province (No. 2020J02002)+1 种基金the Social Science Foundation of Fujian Province (No. FJ2024BF047)the Financial Research Projects of Fujian Province (No. 2024-48)。
文摘Penaeus vannamei, known as the whiteleg shrimp, holds significant economic importance in aquaculture. The intensive culture of P. vannamei poses substantial environmental risks, particularly in fragile ecosystems like estuarine mangroves. Although there is a consensus on the pollution and harmful effects of microplastics(MPs), study on the pollution and potential risks posed by P. vannamei in estuary mangroves remains scarce. Therefore, the extent of microplastic pollution was evaluated and the correlation between the properties of MPs and the potential risks they pose to P. vannamei was examined.The average MP abundance in P. vannamei from Jiulong River estuary was determined to be 0.46±0.03 n/g in five different polymers, i.e., polypropylene(PP), polyethylene(PE), polystyrene(PS), polyethylene terephthalate(PET), and polyvinyl chloride resin(PVC). The total percentage of PS, PE, and PET polymers was the greatest(73.85%), where PET and PP(26.16%) were highly correlated in size and shape. Small MPs(1-200 μm) come in irregular particles, fragments, films, and large-sized MPs(200-1 000 μm) were mainly foam-shaped. The hazard risk level of MPs in P. vannamei from Jiulong River estuary reached grade Ⅲ, and the overall hazard risk index(H) value was 593.66. Among all samples,PVC polymer accounted for the lowest proportion(5.52%), but the H value was as high as 582.42, which contributed 98.11% to the overall hazard risk index. Regardless of global or Chinese, the microplastic pollution of P. vannamei in the estuary is at a moderate level. The protocol for MPs characteristics and correlation in seafood should be the basis for the risk assessment framework. Further studies are needed to evaluate how the exposure to MPs poses a risk for human health.
基金Supported by the National Natural Science Foundation of China(No.21936004)the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(No.SML2021SP208)the Fundamental Research Funds for the Central Universities(No.21623118)。
文摘Ingestion of microplastics by various organisms has been widely evidenced.Chemicals associated with microplastics(MPs)may be released to digestive tracts upon ingestion.However,the effect of aging and temperature on the chemical desorption for MPs remains poorly understood.The exposure of polyethylene(PE)particles to UV radiation in dry air,tap water,and sea water was conducted to mimic the aging process of MPs in different environments.Polychlorinated biphenyls(PCBs),as a typical hydrophobic organic contaminant,were preloaded in these aged and pristine PE.The desorption was performed by exposing preloaded PE particles in simulated gastric and gut fluids at 25℃and 40℃.After UV aging,the average diameter of PE particles decreased rapidly with aging time,indicating continuously fragmentation of PE under UV exposure.The desorption of PCBs from PE particles under different conditions varied from 7%to 40%,and that from aged PE in gut fluid at 37℃was significantly higher than those under other conditions(P<0.05).Furthermore,a clear declining trend was observed as lg K_(ow)(octanol-water partition coefficient)value increased.The aging process,hydrophobicity of chemicals,and incubation temperature were important factors on the desorption of PCBs from PE.The present study helps understand the desorption of PCBs from microplastics and the potential risks of microplastics ingestion by organisms.
基金Cultivation fund in Second Hospital of Shandong University(Grant No.2023YP11).
文摘Glucocorticoids are widely utilized for treating various immune and inflammation-related diseases,prompting significant interest in their potential application for COVID-19 treatment.This study explored the efficacy and safety of dexamethasone(DEX)and methylprednisolone(MP)in treating severe COVID-19.A cohort of 94 adult patients,aged 18 years and older,with severe COVID-19 was recruited.They received intravenous MP(40-80 mg/d)or DEX(5-10 mg/d)for 7-10 d.The primary objective was to assess the effects of these treatments on mortality rates.Additionally,the study aimed to compare the impact of these medications on various parameters,including the oxygenation index,inflammatory index,fungal infections,and hyperglycemia,serving as secondary endpoints.The findings revealed no fatalities in either group.However,there was one case of pulmonary fibrosis and Aspergillus fumigatus infection in the DEX group,and two cases of Aspergillus infection in the MP group.Although the differences were not statistically significant(P>0.05),the MP group showed a faster improvement in blood oxygen saturation compared to the DEX group,with a median time of 5 d vs 7 d.No statistically significant difference was observed between the two groups regarding improvement in C-reactive protein levels(P>0.05).Notably,DEX was associated with a higher incidence of hyperglycemia compared to MP(P<0.05).Both DEX and MP significantly reduced mortality rates among patients with severe COVID-19 and improved blood oxygen saturation and inflammatory markers.However,MP exhibited a more rapid onset of efficacy and fewer adverse reactions.
基金Supported by the National Natural Science Foundation of China(No.41961144011)。
文摘Microplastics(MPs)pollution has emerged as a critical global environmental issue,for which rivers serve as key conduits for the transport of MPs from land to ocean.There remained a lack of clarity regarding the characteristics and transport patterns of MPs pollution in diverse environmental media and seasons within a river basin.The Jiulong River basin in Fujian,southeast China was studied as case,whose spatial-temporal distribution,pollution characteristics,and transport dynamics of MPs in both surface water and groundwater were analyzed.Additionally,the features of MPs in different land use types during the dry season were examined.Results show that in wet season,the abundance of MPs in river water varied from 840 to 12300 p/m^(3),with an average of 3920 p/m^(3);in groundwater,the range was 740-1820 p/m^(3),averaging 1107 p/m^(3);and from 68 to 951 p/kg,with an average value of 265 p/kg in the soil(dry weight).In dry season,levels of MPs in river water ranged from 580 to 8880 p/m^(3),with an average of 4034 p/m^(3);groundwater exhibited a range of 860-14980 p/m^(3),averaging 3453 p/m^(3).Fibers consistently dominated the morphology of MPs,of which polyethylene terephthalate was identified as the predominant composition in each environmental medium.Our findings underscore the spatial and temporal variability in distribution and contamination characteristics of MPs across different media.Notably,MPs abundance in river water and groundwater exhibited a seasonal pattern,being higher in levels in dry season than in wet season.The downstream transport of MPs was facilitated by surface runoff,in which MPs in groundwater and surface water could complement to each other.Furthermore,population density and human activities were identified as influential factors on the distribution and abundance of MPs.This study revealed the order of magnitude of difference in annual estimates of MPs entering the sea among different models.Additionally,the interception volume by mangrove forest in the Jiulong River estuary was estimated approximately 1.51×10^(10)MPs particles per year.Ecological interception shall be considered when estimating the fluxes of MPs into the sea.
