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Urban green spaces play a crucial role in cities by providing near-natural environments that greatly impacts the health of residents. However, these green spaces have recently been scrutinized as potential reservoirs of antibiotic resistance genes (ARGs), posing significant ecological risks. Despite this concern, our understanding of the distribution, sources, and ecological risks associated with ARGs remains limited. In this study, we investigated the spatial distribution of soil ARGs using spatial interpolation and auto-correlation analysis. To apportion the source of soil ARGs in urban green spaces of Tianjin, Geo-detector method (GDM) was employed. Furthermore, we evaluated the ecological risk posed by ARGs employing risk quotients (RQ). The results of our study showed a significantly higher abundance of Quinolone resistance genes in the soil of urban green spaces in Tianjin. These genes were mainly found in the northwest, central, and eastern regions of the city. Our investigation identified three main factors contributing to the presence of soil ARGs: antibiotic production, precipitation, livestock breeding, and hospital. The results of ecological risk in RQ value showed a high risk associated with Quinolone resistance genes, followed by Aminoglycoside, Tetracycline, Multidrug, MLSB, Beta Lactam, Sulfonamide, and Chloramphenicol. Mantel-test and correlation analysis revealed that the ecological risk of ARGs was greatly influenced by soil properties and heavy metals. This study provides a new perspective on source apportionment and the ecological risk assessment of soil ARGs in urban green spaces.
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Cidades , Microbiologia do Solo , Medição de Risco , China , Resistência Microbiana a Medicamentos/genética , Monitoramento Ambiental , Solo/química , Antibacterianos/análise , Farmacorresistência Bacteriana/genéticaRESUMO
The emergence of antibiotic resistance is a severe threat to public health. There are few studies on the effects of sewage discharge on antibiotics and antibiotic resistance genes (ARGs) contamination in Jiaozhou Bay sediment. Herein, a total of 281 ARG subtypes, 10 mobile genetic elements (MGEs), 10 antibiotics and bacterial communities in marine sediments from Jiaozhou Bay were characterized. Similar bacterial community structures and ARG profiles were identified between the various sampling sites inside the bay, which were both dominated by multidrug and (fluoro)quinolone resistance genes and harbored lower relative abundances of ARGs than those in the sampling sites near the bay exit. Compared with antibiotics and MGEs, bacterial community composition was a more important driver of ARG diversity and geographic distribution. The abundance of pathogens carrying genetic information increased dramatically in southern Jiaozhou Bay is affected by sewage discharge, which indicating that wastewater discharge facilitated ARG contamination of marine sediments. This study highlights the risk of disseminating antibiotic resistance-influencing factors from treated wastewater discharge into marine environment there is an urgent need to optimize or improve wastewater treatment processes to enhance the removal of antibiotics and ARGs. This study has necessary implications for filling the gap in information on antibiotic resistance in Jiaozhou Bay and developing future pollution regulation and control measures.
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Esgotos , Águas Residuárias , Genes Bacterianos , Baías , Bactérias/genética , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/genética , Sedimentos Geológicos , ChinaRESUMO
Wild birds are known to harbor and discharge antibiotic-resistant bacteria (ARB) and their associated antibiotic resistance genes (ARGs). However, assessments of their contribution to the dissemination of antibiotic resistance in the environment are limited to culture-dependent bacterial snapshots. Here, we present a high-throughput sequencing study that corroborates extensive ARG exchange between wild bird feces and their habitats and implies the need to scrutinize high-mobility birds as potential vectors for global propagation of ARGs. We characterized the resistome (281 ARGs) and microbiome of seven wild bird species and their terrestrial and aquatic habitats. The resistomes of bird feces were influenced by the microbial community structure, mobile genetic elements (MGEs), and residual antibiotics. We designated 33 ARGs found in more than 90% of the bird fecal samples as core ARGs of wild bird feces, among which 16 ARGs were shared as core ARGs in both wild bird feces and their habitats; these genes represent a large proportion of both the bird feces (35.0 ± 15.9%) and the environmental resistome (29.9 ± 21.4%). One of the most detected ß-lactam resistance genes (blaTEM, commonly harbored by multidrug resistant "superbugs") was used as molecular marker to demonstrate the high interconnectivity of ARGs between the microbiomes of wild birds and their habitats. Overall, this work provides a comprehensive analysis of the wild bird resistome and underscores the importance to consider genetic exchange between animals and the environment in the One Health approach.
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Antibacterianos , Microbiota , Animais , Antibacterianos/farmacologia , Genes Bacterianos , Antagonistas de Receptores de Angiotensina/farmacologia , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Resistência Microbiana a Medicamentos/genética , Aves , Animais SelvagensRESUMO
Metal concentration in marine sediments is influenced by sedimentation rate. In this study, the metal concentration in sediments of Bohai Bay, China, was adjusted by sedimentation rate, which was derived from the radionuclide dating method. The results showed that the sedimentation rate of Bohai Bay sediments increased from 0.3 to 0.55 g/a over time, especially in the last 30 years since the economic reform in China. The sequence of metal concentrations (mg/kg) is: Cr(97.41) > Zn(73.14) > Cu(20.59) > Pb(16.42) > Cd(0.49). Through the adjustment, the change of metal concentration in sediment cores increased obviously from bottom to surface sediments. It indicated that the increasing sedimentation rate of Bohai Bay in recent years diluted the metal concentration in the sediment.
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Baías/química , Sedimentos Geológicos/química , Metais Pesados/análise , China , Monitoramento Ambiental , Metais Pesados/química , Fatores de Tempo , Poluentes Químicos da Água/análiseRESUMO
Eutrophication and climate change may affect the top-down versus bottom-up controls in aquatic ecosystems. However, the relative prevalence of the two controls in planktonic ecosystems along the eutrophication and climate gradients has rarely been addressed. Here, using the field surveys of 17 years in a typical bay and estuary, we test two opposite patterns of trophic control dominance and their response to regional temporal eutrophication and climate fluctuations. It was found that trophic control of planktonic ecosystems fluctuated between the dominance of top-down and bottom-up controls on time scales in both the bay and estuary studied. The relative prevalence of these two controls in both ecosystems was significantly driven directly by regional dissolved inorganic nitrogen but, for the estuary, also by the nonlinear effects of regional sea surface temperature. In terms of indirect pathways, community relationships (synchrony and grazing pressure) in the bay are driven by both regional dissolved inorganic nitrogen - soluble reactive phosphorus ratio and sea surface temperature, but this drive did not continue to be transmitted to the trophic control. Conversely, trophic control in estuary was directly related to grazing pressure and indirectly related to synchrony. These findings support the view that eutrophication and climate drive the relative prevalence of top-down versus bottom-up controls at ecosystem and temporal scales in planktonic ecosystems, which has important implications for predicting the potential impacts of anthropogenic and environmental perturbations on the structure and function of marine ecosystems.
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Extracellular polymeric substances (EPS) secreted by organisms tend to encapsulate microplastics (MPs), forming an EPS-corona that affects the fate of MPs in marine ecosystems. However, the impact of the EPS-corona on the biotoxicity of MPs to marine organisms remains poorly understood. Herein, the effect of the EPS-corona on the toxicity of polystyrene (PS) MPs of different sizes (0.1 and 1 µm) to Skeletonema costatum (S. costatum) was investigated. The preferential adsorption of medium molecule weight (â¼55 kDa) proteins onto PS MPs mainly contributed to the EPS-corona formation, decreasing the surface charge negativity of small-sized PS MPs (0.1 µm) by 72.4 %. Nitrogen (N) and oxygen (O) moieties in polysaccharides and proteins were identified as the preferential adsorption sites in the EPS-PS MPs interaction. Density functional theory (DFT) calculations confirmed the nuclear magnetic resonance spectroscopy (NMR) results, revealing that the binding mode between EPS and PS MPs was mainly hydrogen bonding. In addition, EPS-corona increased the cell density of S. costatum by 35.5-36.0 % when exposed to small-sized PS MPs (0.1 µm, 25-50 mg/L). These findings provide new insights into how EPS-corona affects the environmental fate and ecological risks associated with micro- and nano-sized plastics in marine ecosystems.
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Matriz Extracelular de Substâncias Poliméricas , Microplásticos , Poliestirenos , Poluentes Químicos da Água , Microplásticos/toxicidade , Microplásticos/química , Adsorção , Poliestirenos/toxicidade , Poliestirenos/química , Matriz Extracelular de Substâncias Poliméricas/metabolismo , Matriz Extracelular de Substâncias Poliméricas/química , Poluentes Químicos da Água/toxicidade , Poluentes Químicos da Água/química , Proteínas/química , Proteínas/metabolismo , Peso Molecular , Diatomáceas/efeitos dos fármacos , Diatomáceas/metabolismo , Tamanho da PartículaRESUMO
Macroinvertebrates play a vital role in coastal ecosystems and are an important indicator of ecosystem quality. Both anthropogenic activity and environmental changes may lead to significant changes in the marine macroinvertebrate community. However, the assembly process of benthic biodiversity and its mechanism driven by environmental factors at large scales remains unclear. Here, using the benthic field survey data of 15 years at large spatial and temporal scales from the Yellow Sea Large Marine Ecosystem, we investigated the relative importance of environmental selection, dispersal processes, random-deterministic processes of macroinvertebrates community diversity assembly, and the responses of this relative importance driven by temperature and nutrients. Results showed that the macroinvertebrates community diversity is mainly affected by dispersal. Nitrogen and phosphorus are the most important negative factors among environmental variables, while geographical distance is the main limiting factor of ß diversity. Within the range of 0.35-0.70 mg/L of nutrients, increasing nutrient concentration can significantly facilitate the contribution of the decay effect to ß diversity. Within the temperature range studied (15.0-18.0°C), both warming and cooling can lead to a greater tendency for species diversity assembly processes to be dominated by deterministic processes. The analysis contributes to a better understanding of the assembly process of the diversity of coastal marine macroinvertebrates communities and how they adapt to global biogeochemical processes.
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Biochar is a widely proposed solution for improving degraded soil in coastal wetland ecosystems. However, the impacts of biochar addition on the soil and plant communities in the wetland remains largely unknown. In this study, we conducted a greenhouse experiment using soil seed bank from a coastal saline-alkaline wetland. Three types of biochar, including Juglans regia biochar (JBC), Spartina alterniflora biochar (SBC) and Flaveria bidentis biochar (FBC), were added to the saline-alkaline soil at ratios of 1%, 3% and 5% (w/w). Our findings revealed that biochar addition significantly increased soil pH, and increased available potassium (AK) by 3.74% - 170.91%, while reduced soil salinity (expect for 3% SBC and 5%SBC) by 28.08% - 46.93%. Among the different biochar types, the application of 5% FBC was found to be the most effective in increasing nutrients and reducing salinity. Furthermore, biochar addition generally resulted in a decrease of 7.27% - 90.94% in species abundance, 17.26% - 61.21% in community height, 12.28% - 56.42% in stem diameter, 55.34% - 90.11% in total biomass and 29.22% - 78.55% in root tissue density (RTD). In particular, such negative effects was the worst in the SBC samples. However, 3% and 5% SBC increased specific root length (SRL) by 177.89% and 265.65%, and specific root surface area (SRSA) by 477.02% and 286.57%, respectively. The findings suggested that the plant community performance was primarily affected by soil pH, salinity and nutrients levels. Furthermore, biochar addition also influenced species diversity and functional diversity, ultimately affecting ecosystem stability. Therefore, it is important to consider the negative findings indirectly indicate the ecological risks associated with biochar addition in coastal salt-alkaline soils. Furthermore, Spartina alterniflora was needed to desalt before carbonization to prevent soil salinization when using S. alterniflora biochar, as it is a halophyte.
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Micro(nano)plastics (MNPs) inevitably interact with coexisting contaminants and can act as vectors to affect their fate in organisms. However, the quantitative contribution of MNPs in the in vivo bioaccumulation and distribution of their coexisting contaminants remains unclear. Here, by selecting tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) as the typical coexisting contaminant, we quantified the contribution of MNPs to bioaccumulation and distribution of TDCIPP with toxicokinetic models. Results indicated that MNPs differentially facilitated TDCIPP bioaccumulation and distribution, and NPs slowed down TDCIPP depuration more significantly than MPs. Model analysis further revealed increasing contributions of MNPs to whole-fish TDCIPP bioaccumulation over time, with NPs (33-42%) contributing more than MPs (12-32%) at 48 h exposure. NPs contributed more than MPs to TDCIPP distribution in the liver (13-19% for MPs; 36-52% for NPs) and carcass (24-45% for MPs; 57-71% for NPs). The size-dependent vector effect might be attributed to the fact that MNPs promote contaminant transfer by damaging biofilm structure and increasing tissue membrane permeability, with NPs exerting stronger effects. This work demonstrated the effectiveness of using modeling tools to understand the relative importance of MNPs as contaminant vectors in the TK process and highlighted the higher contaminant transfer potential of NPs under combined exposure scenarios.
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Fosfatos , Poluentes Químicos da Água , Animais , Peixe-Zebra , Compostos Organofosforados/toxicidade , Plásticos , ToxicocinéticaRESUMO
For coastal eutrophication, lots of studies focused on the influence from environmental factors, especially nitrogen and phosphorus, on algae blooms. The interaction between algae and environmental factors has been often ignored. Using Chattonella marina, a dominant species in marine algal blooms, we established a trophic gradient system that simulated C. marina blooms at three trophic levels: eutrophic, mesotrophic, and oligotrophic, and examined the life history patterns of C. marina and the interactions with environmental factors. Increased trophic levels influenced the growth potential of C. marina, while its unique cyst reproduction allowed it to thrive in nutrient-limited environments. Adequate nutrients caused changes in dissolved oxygen (DO) and pH led by C. marina, with the carbonate system playing a crucial role in regulating pH under nutrient-limited conditions. Limiting the growth of C. marina in areas with low nutrient by manipulating reactive silicate (SiO32-) availability may prove effective. Nitrate (NO3-) was the preferred nutrient for C. marina when its concentration exceeded that of ammonium (NH4+). Phosphorus played a crucial role in the growth and proliferation of C. marina, especially when other nutrients were scarce. The findings of this study may provide valuable insights into the effective management and prevention of algae blooms.
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Estramenópilas , Eutrofização , Estado Nutricional , Nutrientes , Nitrogênio , FósforoRESUMO
The increase in alien plant invasions poses a major threat to global biodiversity and ecosystem stability. However, the presence of microplastics (MPs) as an environmental stressor could impact the interactions between invasive and native species in an invasive plant community. Nevertheless, the community alterations and underlying mechanisms resulting from these interactions remain unclear. Herein, we systematically investigated the impacts of polyethylene (PE) and polypropylene (PP) on invasive plant communities invaded by Amaranthus palmeri through soil seed bank. The results illustrated that MPs markedly declined community height and biomass, and altered community structure, low-dose MPs could prominently increase community invasion resistance, but reduced community stability. The niche width and niche overlap of A. palmeri and S. viridis declined when exposed to high-dose MPs, but MPs elicited a significant rise in the niche width of S. salsa. PP had the potential to reduce the diversity of invasive plant community. Structural equation model revealed that PP addition could change soil total phosphorus content, thereby leading to a reduction of the community stability. Our study helps to fill the knowledge gap regarding the effects of MPs on invasive plant communities and provide new perspectives for invasive plant management.
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Amaranthus , Microplásticos , Plásticos , Ecossistema , Plantas , Solo/química , PolipropilenosRESUMO
Small-sized microplastics (MPs) pose greater ecological toxicity due to their larger surface area, which makes them more likely to act as carriers for other pollutants and to be ingested by aquatic organisms. However, traditional visual analysis often neglects small-sized MPs and their associated ecological risk. This study utilized Laser Direct Infrared (LDIR) spectroscopy and traditional visual analysis to examine MPs in 31 sediment samples from Jinzhou Bay, a typical semi-enclosed bay located at the economic center of Dalian, China. The results showed significant heterogeneity in MP distribution, with averages of 1192 and 2361 items/kg dry weight reported by visual analysis and LDIR spectroscopy, respectively. LDIR spectroscopy identified MPs as small as 10 µm, with the majority of MPs (89.21 %) within the 10-250 µm range, and a significant proportion (46.45 %) between 10 and 50 µm among them. However, visual analysis was limited to detecting MPs >50 µm, and significant portions were identified between 50 and 100 µm (49.36 %) and 100-250 µm (31.01 %), missing a substantial fraction of smaller MPs. The predominant polymers identified were polyamide (PA), polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and acrylonitrile butadiene styrene (ABS). LDIR spectroscopy demonstrated a strong positive correlation between MP abundance and clay content, a relationship not observed with traditional visual analysis. The Potential Ecological Risk Index (PERI) indicated that over 87 % of sites posed an extremely high risk according to LDIR spectroscopy, compared to 51 % by traditional visual analysis. These discrepancy underscores the underestimation of ecological risks by traditional methods, particularly for small-sized MPs. High-risk polymers such as polyvinyl chloride (PVC), ABS, and polyurethane (PUR) significantly influenced PERI values. These findings highlight the critical need for precise identification and thorough risk assessment of small-sized MPs in environmental studies and offer insights for understanding of MP vertical migration in aquatic environments, particularly in the context of co-settlement with sediments.
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OBJECTIVE: To employ enzyme-linked immunosorbent assay (ELISA) to measure the serum level of thrombospondin-1 (TSP-1) and analyze its diagnostic value for prostate cancer. METHODS: The serum levels of TSP-1 were measured by human TSP-1 ELISA kit in 50 patients with organ-confined prostate cancer (n = 22) and non-organ-confined prostate cancer (n = 28). And the subjects of benign prostatic hyperplasia (BPH, n = 20) and healthy controls (n = 16) were selected. RESULTS: The average serum concentration of TSP-1 was (200 ± 49) µg/L in prostate cancer group, (281 ± 53) µg/L in BPH group and (323 ± 56) µg/L in healthy control group. There were significant inter-group differences in the serum levels of TSP-1 (both P < 0.05). The average serum concentration of TSP-1 was (216 ± 34) µg/L in organ-confined prostate cancer (including stages I and II) and (188 ± 49) µg/L in non-organ-confined prostate cancer (including stages III and IV) respectively (P = 0.030). The level of TSP-1 was also correlated with Gleason score (r = -0.32, P = 0.023). However, the relationship between TSP-1 levels and lymph node metastasis remained elusive (P = 0.189). The diagnostic sensitivity and specificity of TSP-1 and prostate specific antigen (PSA) for prostate cancer were 72%, 90% and 64%, 70% respectively (both P < 0.05). The area under the receiver operating characteristic curve (ROC) of TSP-1 and PSA were 0.886 and 0.719 respectively (P = 0.028). CONCLUSION: As a relatively ideal predictor of prostate cancer, the serum concentration of TSP-1 can not only distinguish prostate cancer from BPH, but also correlate with tumor stage and Gleason grade.
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Neoplasias da Próstata/diagnóstico , Trombospondina 1/sangue , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias da Próstata/sangue , Sensibilidade e EspecificidadeRESUMO
Antibiotics and nanoplastics are widely detected in the coastal ecosystem. However, the transcriptome mechanism elucidating the effect of antibiotics and nanoplastics co-exposure on the gene expression of aquatic organisms in coastal environment is still unclear. Here, single and joint effects of sulfamethoxazole (SMX) and polystyrene nanoplastics (PS-NPs) on the intestinal health and gene expression of medaka juveniles (Oryzias melastigma), which live in coastal environment, were investigated. The SMX and PS-NPs co-exposure decreased intestinal microbiota diversity compared to the PS-NPs, and caused more adverse effect on the intestinal microbiota composition and intestinal damage compared to the SMX, indicating that PS-NPs might enhance the toxicity of SMX on the medaka intestine. The increased abundance of Proteobacteria in the intestine was observed in the co-exposure group, which might induce the intestinal epithelium damage. In addition, the differentially expressed genes (DEGs) were mainly involved in the drug metabolism-other enzymes, drug metabolism-cytochrome P450, metabolism of xenobiotics by cytochrome P450 pathways in visceral tissue after the co-exposure. The expression of the host immune system genes (e.g., ifi30) could be associated with the increased pathogens in intestinal microbiota. This study is useful for understanding the toxicity effect of antibiotics and NPs on aquatic organisms in coastal ecosystem.
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Oryzias , Poluentes Químicos da Água , Animais , Microplásticos/toxicidade , Microplásticos/metabolismo , Oryzias/metabolismo , Sulfametoxazol/toxicidade , Sulfametoxazol/metabolismo , Ecossistema , Poliestirenos/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Antibacterianos/metabolismo , Intestinos , Poluentes Químicos da Água/análiseRESUMO
A complete mitochondrial genome (mitogenome) can provide important information for gene rearrangement, molecular evolution and phylogenetic analysis. Currently, only a few mitogenomes of hermit crabs (superfamily Paguridae) in the infraorder Anomura have been reported. This study reports the first complete mitogenome of the hermit crab Diogenes edwardsii assembled using high-throughput sequencing. The mitogenome of Diogenes edwardsii is 19,858 bp in length and comprises 13 protein-coding genes, 2 ribosomal RNA genes, and 22 transfer RNA genes. There are 28 and six genes observed on the heavy and light strands, respectively. The genome composition was highly A + T biased (72.16%), and exhibited a negative AT-skew (-0.110) and positive GC-skew (0.233). Phylogenetic analyses based on the nucleotide dataset of 16 Anomura species indicated that D. edwardsii was closest related to Clibanarius infraspinatus in the same family, Diogenidae. Positive selection analysis showed that two residues located in cox1 and cox2 were identified as positively selected sites with high BEB value (>95%), indicating that these two genes are under positive selection pressure. This is the first complete mitogenome of the genus Diogenes, and this finding helps us to represent a new genomic resource for hermit crab species and provide data for further evolutionary status of Diogenidae in Anomura.
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Anomuros , Genoma Mitocondrial , Animais , Anomuros/genética , Filogenia , Evolução Molecular , Rearranjo GênicoRESUMO
The stress produced from biodegradable plastics on soil ecosystem is a rising global concern. However, effects of such microplastics (MPs) on soil ecology are still debatable. In this study, the biodegradable microplastic PBAT (polyadipate/butylene terephthalate) was used as the target object, compared with the traditional microplastic LDPE (low-density polyethylene). A pot experiment and was high-throughput sequencing analysis used to determine the effect of different additions of MPs on soil bacterial community structure and the correlation between soil bacterial community structure and chemical properties was investigated. Compared with LDPE, the results showed that EC, TN, TP, NH4+-N, and NO3--N changed obviously with the increasing of PBAT addition (p < 0.05), but pH changed little and the community richness was significantly higher in soils with low PBAT addition than that with higher PBAT addition. PBAT is beneficial to soil nitrogen fixation, but it will significantly reduce the soil P content and affect the nitrification and denitrification reaction. It suggested that addition of PBAT MPs and its addition amount result in changes in soil fertility, community abundance, and structure and composition of bacterial communities in soil samples, while the presence of PBAT MPs might affect soil carbon-nitrogen cycle.
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Plásticos Biodegradáveis , Microplásticos , Plásticos/química , Polietileno , Ecossistema , Solo/químicaRESUMO
It is thought remediating cadmium pollution with biochar can affect plant traits. However, the potential impact of this practice on plant communities is poorly understood. Here, we established natural-germinated plant communities using soil seed bank from a saline-alkaline wetland and applied a biochar treatment in Cd-polluted wetland soil. The outcomes illustrated that Juglans regia biochar (JBC), Spartina alterniflora biochar (SBC), and Flaveria bidentis biochar (FBC) promoted exchangeable Cd transform into FeMn oxide bound Cd. Additionally, most biochar addition reduced species abundance, root-shoot ratio, biomass, diversity, and community stability, yet enhanced community height. Among all treatments, the 5 % SBC demonstrated the most significant reduction in species abundance, biomass, species richness and functional richness. Specifically, it resulted in a reduction of 92.80 % in species abundance, 73.80 % in biomass, 66.67 % in species richness, and 95.14 % in functional richness compared to the CK. We also observed changes in root morphological traits and community structure after biochar addition. Soil pH, salinity, and nutrients played a dominant role in shaping plant community. These findings have implications for biodiversity conservation, and the use of biochar for the remediation of heavy metals like cadmium should be approached with caution due to its potential negative impacts on plant communities.
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Cádmio , Poluentes do Solo , Cádmio/análise , Áreas Alagadas , Poluentes do Solo/análise , Carvão Vegetal/química , Solo/químicaRESUMO
Microplastics (MPs) undergo aging over time, which can influence their behavior in the environment. While laboratory-simulated studies have investigated MP aging, research on natural aging in various real environments remains limited. This study aims to investigate the physical, chemical and biological changes that occur in five types of MPs after more than 10 months of natural aging in three different real environments: seawater, air and soil. Results are compared with previous laboratory experiments. The surface roughness of all types of aged MPs was found to be higher in seawater than in air and soil, which differed from previous simulated studies that showed the highest roughness in air. All aged MPs exhibited the occurrence of hydroxyl and carbonyl groups due to the oxidation processes. Interestingly, the MPs aged in soil showed the lowest level of these functional groups, while in seawater or air, some MPs demonstrated the highest. This contrasts with previous studies indicating the highest level of oxygen-containing functional groups in aged MPs in air. Bacterial analysis identified fourteen bacterial phyla on the surface of aged MPs in all three real environments, with varying abundance in specific environments. Notably, the composition of bacterial communities in the microplastisphere was determined by the surrounding environments, independent of MP types. Natural aging is more complex than laboratory simulations, and the degree of MP aging increases with the complexity of environmental factors. These findings enhance our understanding of the natural aging of MPs in different real environments.
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Microplásticos , Poluentes Químicos da Água , Plásticos , Radical Hidroxila , SoloRESUMO
Molecularly imprinted polymers (MIPs) have aroused great attention as a new material for the removal or detection of pharmaceuticals and personal care products (PPCPs). However, it is not clear about the superiority and deficiency of MIPs in the process of removing or detecting PPCPs. Herein, we evaluated the performance of MIPs in the aspects of adsorption capacity, binding affinity, adsorption rate, and compatibility to other techniques, and proposed ways to improve its performance. Without regard to the selectivity of MIPs, for the PPCPs adsorption, MIPs surprisingly did not always perform better than the conventional adsorbents (non-imprinted polymers, biochar, activated carbon and resin), indicating that MIPs should be used where selectivity is crucial, for example recovery of specific PPCPs in an environmental sample extraction process. Compared to the traditional solid-phase extraction for PPCPs detection pretreatment, the usage of MIPs as substitute extraction agents could obtain high selectivity of specific substance, due to the uniformity and effectiveness of the specific sites. A promising development in the future would be to combine other simple and rapid quantitative technologies, such as electro/photochemical sensor and catalytic degradation, to realize rapid and sensitive detection of trace PPCPs.
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Impressão Molecular , Adsorção , Polímeros Molecularmente Impressos , Polímeros , Extração em Fase SólidaRESUMO
Microplastics (MPs) and sulfamethoxazole (SMX) are ubiquitous in various aquatic environments, but little is known about their joint toxicity mechanism on marine organisms. This study investigated the individual and joint toxicity of SMX and five MPs, including polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polystyrene (PS) and bioplastic polylactic acid (PLA), on Skeletonema costatum. The inhibition rates (IR) of the single MPs systems (50 mg/L) followed the order of PP > PE > PLA > PS > PET, while the addition of 0.3 mg/L SMX significantly decreased the toxicity of PP, PE and PLA in the joint system due to the "shelter" effect from MPs adsorption. As for the PS and SMX joint system, the malondialdehyde (MDA), reactive oxygen species (ROS) levels and superoxide dismutase (SOD) activity were higher than those of the other joint systems. The metabolomic results showed that SMX downregulated glycerophospholipid and amino acid metabolism. PS caused the downregulation of glycerophospholipids, carbohydrates and amino acid via the hetero-aggregation with algae. The co-exposure of SMX and PS alleviated the perturbation of alanine, aspartate and glutamate metabolism of algae compared with SMX. These findings enhance our understanding of the potential mechanisms of the MPs and organic pollutants joint toxicity in the marine environment.