Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 576
Filtrar
1.
Int Immunopharmacol ; 138: 112597, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38955025

RESUMO

BACKGROUND: Guillain-Barré syndrome (GBS) is an auto-inflammatory peripheral nerve disease. Dendritic cell-mediated T cell polarization is of pivotal importance in demyelinating lesions of peripheral nerves and nerve roots. However, the regulatory function of VX-509 (Decernotinib)-modified tolerogenic dendritic cells (VX-509-tolDCs) during immune remodeling following GBS remains unclear. Here, we used experimental autoimmune neuritis (EAN) as a model to investigate these aspects of GBS. METHODS: DCs were treated with varying concentrations of VX-509 (0.25, 1, and 4 µM) or served as a control using 10-8 M 1,25-(OH)2D3. Flow cytometry was employed to assess the apoptosis, phenotype, and capacity to induce T cell responses of the treated DCs. In the in vivo experiments, EAN mice received administration of VX-509-tolDCs or 1,25-(OH)2D3-tolDCs via the tail vein at a dose of 1x106 cells/mouse on days 5, 9, 13, and 17. RESULTS: VX-509 inhibited the maturation of DCs and promoted the development of tolDCs. The function of antigen-specific CD4 + T cells ex vivo was influenced by VX-509-tolDCs. Furthermore, the adoptive transfer of VX-509-tolDCs effectively alleviated inflammatory demyelinating lesions in EAN by promoting Th17/Treg (T helper 17 and regulatory T cells) rebalance. CONCLUSION: The adoptive transfer of VX-509-tolDCs alleviated inflammatory demyelinating lesions in a mouse model of GBS, known as the EAN mouse, by partially restoring the balance between Treg and Th17 cells.

2.
Front Nutr ; 11: 1408424, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38946781

RESUMO

Objective: There is suggestive data indicating a correlation among dietary protein intake and the progression of chronic kidney disease (CKD). Nonetheless, the exact associations between dietary protein intake and the incidence of CKD have remained uncertain. We performed the first meta-analysis to explore the correlation among total protein, plant protein, animal protein intake and CKD risk. Methods: The study conformed the PRISMA statement guidelines. We comprehensively searched PubMed, Web of Science, and Embase until to December 2023. The retrieved studies underwent rigorous evaluation for eligibility, and relevant data were meticulously extracted. The Newcastle-Ottawa Scale (NOS) tool was applied to evaluate the risk of bias. Subsequently, relevant data were extracted and pooled to evaluate the relations among dietary protein intake and CKD incidence. Results: Totally, 6,191 articles were identified, six studies were eligible. A total of 148,051 participants with 8,746 CKD cases were included. All studies had a low overall risk of bias. Higher total, plant and animal protein intake were all correlated with decreased CKD incidence, pooled risk ratios (RRs) and 95% confidence intervals (CIs) were as follows: (RR = 0.82, 95% CI = 0.71-0.94, p = 0.005; I2 = 38%, p = 0.17); (RR = 0.77, 95% CI = 0.61-0.97, p = 0.03; I2 = 77%, p = 0.001); (RR = 0.86, 95% CI = 0.76-0.97, p = 0.02; I2 = 0%, p = 0.59), respectively. For fish and seafood within animal protein: RR = 0.84, 95% CI = 0.74-0.94. Subgroup analysis showed that geographical region, sample size, follow-up time, not assessing protein by food frequency questionnaire, using %energy as the measurement index, not adjusting for several covariates may be the sources of heterogeneity for plant protein. A significant non-linear relation among plant protein and incident CKD was observed by dose-response analysis. Conclusion: The data showed a lower CKD risk significantly associated higher-level dietary total, plant or animal protein (especially for fish and seafood) intake. Further prospective studies demonstrating the correlations of precise sources, intake and duration of dietary protein and incident CKD are warranted.

3.
Front Chem ; 12: 1416329, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38947956

RESUMO

5-Hydroxymethylfurfural (HMF), serving as a versatile platform compound bridging biomass resource and the fine chemicals industry, holds significant importance in biomass conversion processes. The electrooxidation of HMF plays a crucial role in yielding the valuable product (2,5-furandicarboxylic acid), which finds important applications in antimicrobial agents, pharmaceutical intermediates, polyester synthesis, and so on. Defect engineering stands as one of the most effective strategies for precisely synthesizing electrocatalytic materials, which could tune the electronic structure and coordination environment, and further altering the adsorption energy of HMF intermediate species, consequently increasing the kinetics of HMF electrooxidation. Thereinto, the most routine and effective defect are the anionic vacancies and cationic vacancies. In this concise review, the catalytic reaction mechanism for selective HMF oxidation is first elucidated, with a focus on the synthesis strategies involving both anionic and cationic vacancies. Recent advancements in various catalytic oxidation systems for HMF are summarized and synthesized from this perspective. Finally, the future research prospects for selective HMF oxidation are discussed.

5.
ISME J ; 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38913500

RESUMO

Soil microbial flora constitutes a highly diverse and complex microbiome on Earth, often challenging to cultivation, with unclear metabolic mechanisms in situ. Here, we present a pioneering concept for the in situ construction of functional microbial consortia (FMCs) and introduce an innovative method for creating FMCs by utilising phenanthrene as a model compound to elucidate their in situ biodegradation mechanisms. Our methodology involves single-cell identification, sorting, and culture of functional microorganisms, resulting in the formation of a precise in situ FMC. Through RACS-SIP, we identified and isolated phenanthrene-degrading bacterial cells from Achromobacter sp. and Pseudomonas sp., achieving precise and controllable in situ consortia based on genome-guided cultivation. Our in situ FMC outperformed conventionally designed functional flora when tested in real soil, indicating its superior phenanthrene degradation capacity. We revealed that microorganisms with high degradation efficiency isolated through conventional methods may exhibit pollutant tolerance but lack actual degradation ability in natural environments. This finding highlights the potential to construct FMCs based on thorough elucidation of in situ functional degraders, thereby achieving sustained and efficient pollutant degradation. Single-cell sequencing linked degraders with their genes and metabolic pathways, providing insights regarding the construction of in situ FMCs. The consortium in situ comprising microorganisms with diverse phenanthrene metabolic pathways might offer distinct advantages for enhancing phenanthrene degradation efficiency, such as the division of labour and cooperation or communication among microbial species. Our approach underscores the importance of in situ, single-cell precision identification, isolation, and cultivation for comprehensive bacterial functional analysis and resource exploration, which can extend to investigate MFCs in archaea and fungi, clarifying FMC construction methods for element recycling and pollutant transformation in complex real-world ecosystems.

6.
Mol Biotechnol ; 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38850457

RESUMO

Long intergenic non-coding RNA 239 (Linc00239) acts as an oncogene in colorectal cancer (CRC), esophageal squamous cell carcinoma, and acute myeloid leukemia cells. However, its role and regulatory mechanisms in clear cell renal cell carcinoma (ccRCC) remain unknown. We used StarBase and The Cancer Genome Atlas databases to evaluate Linc00239 expression and its effect on ccRCC. Furthermore, the function of Linc00239 in ccRCC proliferation and metastasis was analyzed using Cell Counting Kit-8 and Transwell assays following Linc00239 knockdown. Subsequently, the Linc00239-miRNA-mRNA regulatory associations were selected based on miRanda, miTarbase, and previous references, and their expression levels and binding relationship were further validated using quantitative real-time polymerase chain reaction, western blotting and dual-luciferase reporter gene assay. Additionally, we transfected a miRNA inhibitor to evaluate whether the miR-204-5p/RAB22A (Ras-related proteins in brain 22a) axis was involved in Linc00239 function. Linc00239 was elevated in ccRCC and correlated with poor prognosis. Linc00239 knockdown inhibited ccRCC progression. Additionally, Linc00239 inhibition elevated miR-204-5p expression and repressed RAB22A levels. Moreover, miR-204-5p inhibitors attenuated this inhibitory effect on proliferation, migration, invasion, and RAB22A level when Linc00239 was knocked down. Linc00239 promotes ccRCC proliferation and metastasis by elevating RAB22A expression through the adsorption of miR-204-5p, which provides a clue for the diagnosis and treatment of ccRCC.

7.
Sci Total Environ ; 943: 173814, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-38848915

RESUMO

The mattic layer is a main ecological function bearer of alpine meadow soils in the Qinghai-Tibet Plateau. It has high soil organic carbon (SOC) content with a variety of SOC fractions, which are thought to have different sensitivities to climate change. The effects of soil properties and climate on the SOC fractions in the mattic layer are not well understood. To address this, we analyzed the effects of environmental factors on two SOC fractions: particulate organic carbon (POC) and mineral-associated organic carbon (MAOC). A random forest model (RFM), partial correlation analysis, and structural equation model (SEM) were used to quantify the relative effects of soil and climatic factors on SOC fractions. We found that SOC and its fractions are primarily regulated by soil properties rather than climate. Partial correlation analysis and SEM revealed that climate indirectly affects SOC by influencing soil properties. Silt+Clay and exchangeable calcium (Caex) were found to be the strongest contributing factors of MAOC and POC, respectively. A distinct shift occurs in the mechanism underlying SOC stabilization with varying soil pH. In acidic and neutral environments, amorphous Al/Fe-(hydr) oxides contribute to the stability of MAOC, whereas free Al/Fe-(hydr) oxides promote SOC mineralization. Conversely, Caex positively influences the stabilization of both POC and MAOC throughout the pH range. These results can be extrapolated to predict SOC dynamics in future soil conditions affected by environmental change, especially for use in Earth system models.

8.
Virology ; 596: 110101, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38754335

RESUMO

This study characterizes a newly isolated Demerecviridae phage, named vB_SalS_PSa2, belonging to the phage T5 group. The main variations between vB_SalS_PSa2 and T5 concern structural proteins related to morphology and host recognition. vB_SalS_PSa2 is infective to 19 out of the 25 tested Salmonella enterica (including the rare "Sendai" and "Equine" serotypes) and Escherichia coli isolates, most of them being multidrug resistant. vB_SalS_PSa2 displayed good thermal stability (4-60 °C) and broad pH stability (4.0-12.0). It also exhibited antibacterial activity against S. enterica sv. Paratyphi A Enb50 at 4 °C in milk during the whole tested period (5 d), and for 3-6 h at both 25 and 37 °C. Furthermore, vB_SalS_PSa2 was able to inhibit biofilm formation and to show degradation activity on mature biofilms of E. coli K12 and S. enterica sv. Paratyphi Enb50 in both LB and milk. Altogether, these results indicate that phage vB_SalS_PSa2 is a valuable candidate for controlling foodborne S. enterica and E. coli pathogens.


Assuntos
Escherichia coli , Salmonella enterica , Salmonella enterica/virologia , Escherichia coli/virologia , Leite/virologia , Animais , Microbiologia de Alimentos , Genoma Viral , Biofilmes/crescimento & desenvolvimento , Fagos de Salmonella/fisiologia , Fagos de Salmonella/isolamento & purificação , Fagos de Salmonella/classificação , Fagos de Salmonella/genética , Bacteriófagos/fisiologia , Bacteriófagos/genética , Bacteriófagos/classificação , Bacteriófagos/isolamento & purificação , Concentração de Íons de Hidrogênio , Filogenia , Especificidade de Hospedeiro
9.
Appl Environ Microbiol ; 90(6): e0066224, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38752833

RESUMO

Fungal-bacterial consortia enhance organic pollutant removal, but the underlying mechanisms are unclear. We used stable isotope probing (SIP) to explore the mechanism of bioaugmentation involved in polycyclic aromatic hydrocarbon (PAH) biodegradation in petroleum-contaminated soil by introducing the indigenous fungal strain Aspergillus sp. LJD-29 and the bacterial strain Pseudomonas XH-1. While each strain alone increased phenanthrene (PHE) degradation, the simultaneous addition of both strains showed no significant enhancement compared to treatment with XH-1 alone. Nonetheless, the assimilation effect of microorganisms on PHE was significantly enhanced. SIP revealed a role of XH-1 in PHE degradation, while the absence of LJD-29 in 13C-DNA indicated a supporting role. The correlations between fungal abundance, degradation efficiency, and soil extracellular enzyme activity indicated that LJD-29, while not directly involved in PHE assimilation, played a crucial role in the breakdown of PHE through extracellular enzymes, facilitating the assimilation of metabolites by bacteria. This observation was substantiated by the results of metabolite analysis. Furthermore, the combination of fungus and bacterium significantly influenced the diversity of PHE degraders. Taken together, this study highlighted the synergistic effects of fungi and bacteria in PAH degradation, revealed a new fungal-bacterial bioaugmentation mechanism and diversity of PAH-degrading microorganisms, and provided insights for in situ bioremediation of PAH-contaminated soil.IMPORTANCEThis study was performed to explore the mechanism of bioaugmentation by a fungal-bacterial consortium for phenanthrene (PHE) degradation in petroleum-contaminated soil. Using the indigenous fungal strain Aspergillus sp. LJD-29 and bacterial strain Pseudomonas XH-1, we performed stable isotope probing (SIP) to trace active PHE-degrading microorganisms. While inoculation of either organism alone significantly enhanced PHE degradation, the simultaneous addition of both strains revealed complex interactions. The efficiency plateaued, highlighting the nuanced microbial interactions. SIP identified XH-1 as the primary contributor to in situ PHE degradation, in contrast to the limited role of LJD-29. Correlations between fungal abundance, degradation efficiency, and extracellular enzyme activity underscored the pivotal role of LJD-29 in enzymatically facilitating PHE breakdown and enriching bacterial assimilation. Metabolite analysis validated this synergy, unveiling distinct biodegradation mechanisms. Furthermore, this fungal-bacterial alliance significantly impacted PHE-degrading microorganism diversity. These findings advance our understanding of fungal-bacterial bioaugmentation and microorganism diversity in polycyclic aromatic hydrocarbon (PAH) degradation as well as providing insights for theoretical guidance in the in situ bioremediation of PAH-contaminated soil.


Assuntos
Aspergillus , Biodegradação Ambiental , Consórcios Microbianos , Fenantrenos , Microbiologia do Solo , Poluentes do Solo , Fenantrenos/metabolismo , Poluentes do Solo/metabolismo , Aspergillus/metabolismo , Pseudomonas/metabolismo , Pseudomonas/genética , Bactérias/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Fungos/metabolismo , Fungos/genética , Fungos/classificação
10.
Environ Pollut ; 355: 124259, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38810680

RESUMO

The global increase in electronic waste (e-waste) has led to a rise in informal recycling, emitting hazardous heavy metals (HMs) that threaten human health and ecosystems. This study presents the first comprehensive assessment of HM levels in dry deposition and soils at proximity of forty (40) informal e-waste recycling sites across Pakistan, between September 2020 to December 2021. Findings reveal that Zn (1410), Pb (410) and Mn (231) exhibited the higher mean deposition fluxes (µg/m2.day), derived from air samples, particularly in Karachi. Similarly, soils showed higher mean concentrations (µg/g dw) of Mn (477), Cu (514) and Pb (172) in Faisalabad, Lahore, and Karachi, respectively. HMs concentrations were found higher in winter or autumn and lower in summer. In addition, HM levels were significantly (p = 0.05) higher at recycling sites compared to background sites year-round, highlighting the e-waste recycling operations as the major source of their emissions. The Igeo index indicated moderate to extremely contaminated levels of Cu, Pb, Cd, and Ni in Karachi, Lahore and Gujranwala. Ingestion was found as a leading human exposure route, followed by dermal and inhalation exposure, with Pb posing the greatest health risk. The Cumulative Incremental Lifetime Cancer Risk (ILCR) model suggested moderate to low cancer risks for workers. Strategic interventions recommend mitigating health and environmental risks, prioritizing human health and ecosystem integrity in Pakistan's e-waste management.


Assuntos
Cidades , Resíduo Eletrônico , Metais Pesados , Reciclagem , Poluentes do Solo , Paquistão , Humanos , Metais Pesados/análise , Poluentes do Solo/análise , Solo/química , Monitoramento Ambiental , Poluentes Atmosféricos/análise , Medição de Risco
11.
Environ Res ; 255: 119087, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38719064

RESUMO

Pesticides play a crucial role in securing global food production to meet increasing demands. However, because of their pervasive use, they are now ubiquitous environmental pollutants that have adverse effects on both ecosystems and human health. In this study, the environmental occurrence and fate of 16 current-use pesticides (CUPs) were investigated in 93 forest soil samples obtained from 11 distinct mountains in China. The concentrations of the target pesticides ranged from 0.36 to 55 ng/g dry weight. Cypermethrin, dicofol, chlorpyrifos, chlorothalonil, and trifluralin were the most frequently detected CUPs. The CUP concentrations were generally higher in the O-horizon than in the A-horizon. Chlorpyrifos, chlorothalonil, and dicofol were detected in most deep layers in soil profiles from three mountains selected to represent distinct climate zones. No clear altitudinal trend in organic carbon-normalized concentrations of CUPs was observed in the O- or A-horizons within individual mountains. A negative correlation was noted between the CUP concentrations and the altitudes across all sampling sites. This indicated that proximity to emission sources was a key factor affecting the spatial distribution of CUPs in mountain forest soil on a national scale. The ecological risk assessment showed that dicofol and cypermethrin pose potential risks to earthworms. This study emphasizes the importance of source control when setting management strategies for CUPs.


Assuntos
Monitoramento Ambiental , Florestas , Praguicidas , Poluentes do Solo , China , Poluentes do Solo/análise , Praguicidas/análise , Solo/química
12.
Environ Pollut ; 355: 124216, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38797350

RESUMO

The Three Gorges Reservoir (TGR) is totally manmade, strongly influenced by anthropogenic activity, and lies on the upper reaches of Yangtze River. The periodic storage and discharge of water from the Three Gorges Dam could have altered the original air-plant/soil interactions of contaminants in TGR. Herein, paired atmospheric gas-particle, air-plant, and air-soil samples were collected to investigate the air-plant interaction and air-soil exchange of 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs). The air-plant interaction based on McLachlan's framework to our datasets suggests that PAHs were absorbed via gaseous deposition that was restricted by the plant-gas dynamic equilibrium. The equilibrium indicates a dynamic balance between the gaseous phase and plant surface in PAH absorption. The main limiting factor influencing the PAH uptake was the plant species rather than the atmospheric PAH concentration. The air-soil exchange of PAHs exhibited a net volatilization flux of 16.71 ng/m2/d from the soil to the air based on annual average. There was more volatilization and less deposition in summer and more deposition and less volatilization in autumn and winter. The soil serves as a secondary source of atmospheric PAHs. As the first attempt on probing the multi-interface geochemical process of PAHs, this study highlights the influence of manual water level manipulation from the TGD and environmental factors (such as temperature, humidity, and soil properties) on the regional fate of PAHs in the TGR.


Assuntos
Poluentes Atmosféricos , Monitoramento Ambiental , Hidrocarbonetos Policíclicos Aromáticos , Poluentes do Solo , Solo , Hidrocarbonetos Policíclicos Aromáticos/análise , China , Poluentes Atmosféricos/análise , Solo/química , Poluentes do Solo/análise , Plantas/metabolismo , Poluentes Químicos da Água/análise , Humanos
13.
Chemosphere ; 359: 142324, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38740339

RESUMO

Seawater warming, ocean acidification and chemical pollution are the main threats to coral growth and even survival. The legacy persistent organic contaminants (POCs), such as polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs), and the emerging contaminants, including polybrominated diphenyl ethers (PBDEs), dechlorane plus (DPs) and novel brominated flame retardants (NBFRs) were studied in corals from Luhuitou fringing reef in Sanya Bay and Yongle atoll in Xisha Islands, the South China Sea (SCS). Total average concentrations of ∑16PAHs, ∑23OCPs, ∑34PCBs, ∑8PBDEs, ∑2DPs and ∑5NBFRs in 20 coral species (43 samples) from the SCS were 40.7 ± 34.6, 5.20 ± 5.10, 0.197 ± 0.159, 3.30 ± 3.70, 0.041 ± 0.042 and 36.4 ± 112 ng g-1 dw, respectively. PAHs and NBFRs were the most abundant compounds and they are likely to be dangerous pollutants for future coral growth. Compared to those found in other coral reef regions, these pollutants concentrations in corals were at low to median levels. Except for PBDEs, POCs in massive Porites were significantly higher than those in branch Acropora and Pocillopora (p < 0.01), as large, closely packed corals may be beneficial for retaining more pollutant. The current study contributes valuable data on POCs, particularly for halogenated flame retardants (HFRs, including PBDEs, DPs and NBFRs), in corals from the SCS, and will improve our knowledge of the occurrence and fate of these pollutants in coral reef ecosystems.


Assuntos
Antozoários , Monitoramento Ambiental , Retardadores de Chama , Éteres Difenil Halogenados , Hidrocarbonetos Clorados , Poluentes Orgânicos Persistentes , Bifenilos Policlorados , Hidrocarbonetos Policíclicos Aromáticos , Água do Mar , Poluentes Químicos da Água , Animais , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise , China , Éteres Difenil Halogenados/análise , Retardadores de Chama/análise , Água do Mar/química , Bifenilos Policlorados/análise , Hidrocarbonetos Clorados/análise , Praguicidas/análise , Recifes de Corais , Oceanos e Mares
14.
Sci Rep ; 14(1): 11825, 2024 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-38783017

RESUMO

In the United States (US), chlamydia is the most frequently reported sexually transmitted infection that is nationally notifiable. We examined trends in chlamydia prevalence in the US in 2011-2016 compared with 2005-2010. Cross-sectional, nationally representative surveys, National Health and Nutrition Examination Surveys (NHANES), were used to compare national chlamydia prevalence estimates from 2011 to 2016 with those from 2005 to 2010, and changes in prevalence since 1999-2004 were also reviewed. Persons aged 18-39 years were included in these analyses. Prevalence of chlamydia was based on results from urine specimens. Results were weighted to represent the U.S. civilian, noninstitutionalized population. The baseline characteristics of the study population were similar in gender, age and race/ethnicity between the two groups (P > 0.05). The overall chlamydia prevalence was 1.88% (95% confidence interval [CI] 1.55-2.22%) in 2011-2016 and 1.57% (95% CI 1.27-1.87%) in 2005-2010, a relative increase of 19.7% (95% CI 0.2-39.2%; P < 0.05) between the two surveys. Increases in chlamydia prevalence was especially concentrated in persons who were male, aged 18 to 29 years, had > high school educational level, never married, age at first sex < 18 years, had 2-5 sexual partners in lifetime and had no past sexually transmitted diagnosis between 2005 and 2016 (P < 0.05). Multivariable logistic regression analysis demonstrated that chlamydia was more prevalent in those aged 18-29 years, being non-Hispanic Blacks, had high school educational level, being widowed/divorced/separated and had > 5 sexual partners. The chlamydia prevalence had an increasing trend from 2005-2010 to 2011-2016. Those with high chlamydia prevalence such as sexually active young adults and Non-Hispanic Black should be screened annually so that infected persons can be diagnosed and they and their sex partners can be treated promptly.


Assuntos
Infecções por Chlamydia , Humanos , Estados Unidos/epidemiologia , Infecções por Chlamydia/epidemiologia , Infecções por Chlamydia/microbiologia , Masculino , Feminino , Adulto , Adolescente , Prevalência , Adulto Jovem , Estudos Transversais , Inquéritos Nutricionais
15.
Sci Total Environ ; 929: 172643, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38649049

RESUMO

Particulate inorganic nitrogen aerosols (PIN) significantly influence air pollution and pose health risks worldwide. Despite extensive observations on ammonium (pNH4+) and nitrate (pNO3-) aerosols in various regions, their key sources and mechanisms in the Tibetan Plateau remain poorly understood. To bridge this gap, this study conducted a sampling campaign in Lhasa, the Tibetan Plateau's largest city, with a focus on analyzing the multiple isotopic signatures (δ15N, ∆17O). These isotopes were integrated into a Bayesian mixing model to quantify the source contributions and oxidation pathways for pNH4+ and pNO3-. Our results showed that traffic was the largest contributor to pNH4+ (31.8 %), followed by livestock (25.4 %), waste (21.8 %), and fertilizer (21.0 %), underscoring the impact of vehicular emissions on urban NH3 levels in Lhasa. For pNO3-, coal combustion emerged as the largest contributor (27.3 %), succeeded by biomass burning (26.3 %), traffic emission (25.3 %), and soil emission (21.1 %). In addition, the ∆17O-based model indicated a dominant role of NO2 + OH (52.9 %) in pNO3- production in Lhasa, which was similar to previous observations. However, it should be noted that the NO3 + volatile organic component (VOC) contributed up to 18.5 % to pNO3- production, which was four times higher than the Tibetan Plateau's background regions. Taken together, the multidimensional isotope analysis performed in this study elucidates the pronounced influence of anthropogenic activities on PIN in the atmospheric environment of Lhasa.

16.
Sci Total Environ ; 929: 172762, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38670350

RESUMO

Organophosphate esters (OPEs) are a class of emerging and ubiquitous contaminants that are attracting increasing attention, and their large-scale use as flame retardants and plasticizers has led to their pervasive presence in the environment, although their broader impacts remain unknown. In this study, 11 OPEs were measured in the atmosphere of Southeast Asia and Southwest China during 2016. The ∑11OPEs were higher in this region (78.0-1670 pg/m3, mean 458 pg/m3) than in many remote areas, lower than in developed regions, and comparable to levels in many developing country cities. Generally, the ∑11OPEs were higher in urban (105-1670 pg/m3, mean 538 pg/m3) than in suburban (78.0-1350 pg/m3, mean 388 pg/m3). Seasonal variations of OPEs in the air were more pronounced in Cambodia and Laos, especially for Triphenyl Phosphate (TPHP). Seasonal variations of ∑11OPEs in most regions correspond to changes in temperature and rainfall. Biomass burning may be also a factor in facilitating OPE emissions from biomass materials or soil into the atmosphere of Southeast Asia. The random forest analysis showed that among these, rainfall had the greatest effect on the seasonal variation of atmospheric OPE concentrations, followed by biomass burning and temperature. The inter-regional variation of ∑11OPEs in Southeast Asia was related to population and economic development in each region. Airflow trajectories indicated that the OPEs in this region were mainly from local sources. The health risk assessment revealed that the inhalation exposure risks of OPEs to the residents in the study areas were very low during the sampling period, but may be increasing.


Assuntos
Poluentes Atmosféricos , Monitoramento Ambiental , Ésteres , Organofosfatos , China , Poluentes Atmosféricos/análise , Organofosfatos/análise , Ésteres/análise , Retardadores de Chama/análise , Estações do Ano , Índia , Atmosfera/química , Poluição do Ar/estatística & dados numéricos
17.
Science ; 384(6692): 233-239, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38603490

RESUMO

Global estimates of the size, distribution, and vulnerability of soil inorganic carbon (SIC) remain largely unquantified. By compiling 223,593 field-based measurements and developing machine-learning models, we report that global soils store 2305 ± 636 (±1 SD) billion tonnes of carbon as SIC over the top 2-meter depth. Under future scenarios, soil acidification associated with nitrogen additions to terrestrial ecosystems will reduce global SIC (0.3 meters) up to 23 billion tonnes of carbon over the next 30 years, with India and China being the most affected. Our synthesis of present-day land-water carbon inventories and inland-water carbonate chemistry reveals that at least 1.13 ± 0.33 billion tonnes of inorganic carbon is lost to inland-waters through soils annually, resulting in large but overlooked impacts on atmospheric and hydrospheric carbon dynamics.

18.
Food Chem ; 450: 139380, 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-38640535

RESUMO

Pyrimethanil (PYR) is a fungicide that is harmful to consumers when present in foods at concentrations greater than maximum permitted residue levels. High-performance immunoprobes and dual-readout strategy may be useful for constructing sensitive lateral flow immunoassay (LFIA). Herein, the prepared litchi-like Au-Ag bimetallic nanospheres (LBNPs) exhibited high mass extinction coefficients and fluorescence quenching constants. Benefiting from LBNPs and dual-readout mode, the limits of detection of LBNPs-CM-LFIA and LBNPs-FQ-LFIA for PYR were 0.957 and 0.713 ng mL-1, which were 2.54- and 3.41-fold lower than that of gold nanoparticles-based LFIA, respectively. The limits of quantitation of LBNPs-CM-LFIA and LBNPs-FQ-LFIA were 3.740 and 1.672 ng mL-1, respectively. LBNPs-LFIA was applied to detect PYR in cucumber and grape samples with satisfactory recovery (90%-111%). LBNPs-LFIA showed good agreement with LC-MS/MS for the detection of PYR in the samples. Accordingly, this sensitive and accurate dual-readout LFIA based on LBNPs can be effectively applied for food safety.


Assuntos
Contaminação de Alimentos , Fungicidas Industriais , Ouro , Nanopartículas Metálicas , Nanosferas , Pirimidinas , Prata , Vitis , Prata/química , Ouro/química , Nanosferas/química , Pirimidinas/química , Pirimidinas/análise , Imunoensaio/métodos , Imunoensaio/instrumentação , Contaminação de Alimentos/análise , Fungicidas Industriais/análise , Fungicidas Industriais/química , Vitis/química , Nanopartículas Metálicas/química , Litchi/química , Cucumis sativus/química , Limite de Detecção
19.
Sci Total Environ ; 927: 172254, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38583609

RESUMO

Socio-economic activities like food trade can increase the uncertainty of human risk of persistent organic pollutants (POPs). We compared the change in model predicted α-hexachlorocyclohexane (α-HCH) cancer risk (CR) with and without grain trade in mainland China. In scenario without grain logistics, α-HCH moved fast away from southern and southeastern China via northward atmospheric transport. However, the grain logistics from northeastern China delivers the α-HCH previously accumulated in northeastern sink back to densely populated areas in recent years, which enhance CR by >50 % in the southern seaboard of China. The northward movement of grain production center and recent grain deficiency in southern provinces induced by dietary pattern changes is identified as the major driving factors of the reversed transport of α-HCH. The finding highlights the potential of socio-economic activities that can otherwise offset the risk reduction effect of the geochemical cycle of POPs.


Assuntos
Grão Comestível , Hexaclorocicloexano , China , Hexaclorocicloexano/análise , Humanos , Exposição Ambiental/estatística & dados numéricos , Meios de Transporte , Poluentes Ambientais/análise
20.
Environ Sci Technol ; 58(15): 6682-6692, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38547356

RESUMO

The atmospheric deposition of anthropogenic active nitrogen significantly influences marine primary productivity and contributes to eutrophication. The form of nitrogen deposition has been evolving annually, alongside changes in human activities. A disparity arises between observation results and simulation conclusions due to the limited field observation and research in the ocean. To address this gap, our study undertook three field cruises in the South China Sea in 2021, the largest marginal sea of China. The objective was to investigate the latest atmospheric particulate inorganic nitrogen deposition pattern and changes in nitrogen sources, employing nitrogen-stable isotopes of nitrate (δ15N-NO3-) and ammonia (δ15N-NH4+) linked to a mixing model. The findings reveal that the N-NH4+ deposition generally surpasses N-NO3- deposition, attributed to a decline in the level of NOx emission from coal combustion and an upswing in the level of NHx emission from agricultural sources. The disparity in deposition between N-NH4+ and N-NO3- intensifies from the coast to the offshore, establishing N-NH4+ as the primary contributor to oceanic nitrogen deposition, particularly in ocean background regions. Fertilizer (33 ± 21%) and livestock (20 ± 6%) emerge as the primary sources of N-NH4+. While coal combustion continues to be a significant contributor to marine atmospheric N-NO3-, its proportion has diminished to 22 (Northern Coast)-35% (background area) due to effective NOx emission controls by the countries surrounding the South China Sea, especially the Chinese Government. As coal combustion's contribution dwindles, the significance of vessel and marine biogenic emissions grows. The daytime higher atmospheric N-NO3- concentration and lower δ15N-NO3- compared with nighttime further underscore the substantial role of marine biogenic emissions.


Assuntos
Poluentes Atmosféricos , Carvão Mineral , Humanos , Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Nitrogênio/análise , Isótopos de Nitrogênio/análise , China , Nitratos/análise , Poeira
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...