Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.339
Filtrar
1.
Molecules ; 26(4)2021 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-33669948

RESUMO

To demonstrate the importance of sample preparation used in Fourier transform infrared (FTIR) spectroscopy of microbiological materials, bacterial biomass samples with and without grinding and after different drying periods (1.5-23 h at 45 °C), as well as biogenic selenium nanoparticles (SeNPs; without washing and after one to three washing steps) were comparatively studied by transmission FTIR spectroscopy. For preparing bacterial biomass samples, Azospirillum brasilense Sp7 and A. baldaniorum Sp245 (earlier known as A. brasilense Sp245) were used. The SeNPs were obtained using A. brasilense Sp7 incubated with selenite. Grinding of the biomass samples was shown to result in slight downshifting of the bands related to cellular poly-3-hydroxybutyrate (PHB) present in the samples in small amounts (under ~10%), reflecting its partial crystallisation. Drying for 23 h was shown to give more reproducible FTIR spectra of bacterial samples. SeNPs were shown to contain capping layers of proteins, polysaccharides and lipids. The as-prepared SeNPs contained significant amounts of carboxylated components in their bioorganic capping, which appeared to be weakly bound and were largely removed after washing. Spectroscopic characteristics and changes induced by various sample preparation steps are discussed with regard to optimising sample treatment procedures for FTIR spectroscopic analyses of microbiological specimens.


Assuntos
Azospirillum/química , Nanopartículas/análise , Selênio/análise , Biomassa , Espectroscopia de Infravermelho com Transformada de Fourier
2.
Molecules ; 26(4)2021 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-33671752

RESUMO

Micro- and nanoplastic particles are increasingly seen not only as contaminants themselves, but also as potential vectors for trace organic chemicals (TOrCs) that might sorb onto these particles. An analysis of the sorbed TOrCs can either be performed directly from the particle or TOrCs can be extracted from the particle with a solvent. Another possibility is to analyze the remaining concentration in the aqueous phase by a differential approach. In this review, the focus is on analytical methods that are suitable for identifying and quantifying sorbed TOrCs on micro- and nano-plastics. Specific gas chromatography (GC), liquid chromatography (LC) and ultraviolet-visible spectroscopy (UV-VIS) methods are considered. The respective advantages of each method are explained in detail. In addition, influencing factors for sorption in the first place are being discussed including particle size and shape (especially micro and nanoparticles) and the type of polymer, as well as methods for determining sorption kinetics. Since the particles are not present in the environment in a virgin state, the influence of aging on sorption is also considered.


Assuntos
Microplásticos/análise , Nanopartículas/análise , Plásticos/análise , Poluentes Químicos da Água/análise , Tamanho da Partícula
3.
J Chromatogr A ; 1638: 461859, 2021 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-33465582

RESUMO

In this work we present a comparison exercise between two metrological institutes for size measurement of silica nanoparticles by Asymmetrical Flow Field-Flow Fractionation (AF4) coupled to static light scattering. The work has been performed in the frame of a French inter-laboratory comparison (ILC) exercise organized by the nanoMetrology Club (CnM). The general aim of this multi-technique comparison was to improve the measurement process for each technique, after establishing a well-defined measurement procedure. The results obtained by two national metrological institutes (NMIs), the LNE (France) and the SMD (Belgium) by AF4-UV-DRI-MALS will be presented and discussed. Three different samples were characterized: the reference material ERM®-FD304, which is a suspension of colloidal silica in aqueous solution and two silica bimodal samples consisting of two populations of SiO2 nanoparticles of unknown size in aqueous solution, with different populations' ratios. The procedure for the preparation of the sample before the analysis, and main separation parameters have been previously defined between the two institutes and will be described. The principals measured parameters were the weight-average (dge_w), number-average (dge_n) and z-average (dge_z) geometric diameter; the average hydrodynamic diameter (dh); and the diameter obtained by external calibration using polystyrene latex standards (dcal). Results between the two NMIs were comparable and coherent with the expected size values of those obtained by other techniques like Scanning Mobility Particle Sizer (SMPS) and Scanning Electron Microscopy (SEM) also involved in this ILC exercise. Where discrepancies are observed, they leave the results compatible within their uncertainties and underpin the challenges in analysing data and reporting results, making AF4 a powerful tool to compare to other measurement techniques.


Assuntos
Difusão Dinâmica da Luz , Fracionamento por Campo e Fluxo , Nanopartículas/análise , Dióxido de Silício/química , Academias e Institutos , Bélgica , França , Tamanho da Partícula , Água/química
4.
Chemosphere ; 262: 127295, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32536422

RESUMO

Good air quality is documented as a significant factor of social justice. The human health hazards associated with air pollution are not distributed equally across cities; the most vulnerable people are more exposed to ambient air as they commute to work and wait for buses or trains at the stations. Aerosols play important roles in atmosphere quality and the climate; their oxidation at the nanoscale level may possibly increase the reactivity and toxicity of atmospheric particulates. Indoor school environments are characterized by high concentrations of different airborne particulate and gaseous pollutants. The documentation of nanoparticles (NPs), ultra-fine particles (UFPs), and micron-size particle species present in indoor primary schools are an important aspect in the recognition of their influence in respirational difficulties and decreased cognitive progress in children. This work utilizes the study of condensed water, sampled with portable dehumidifiers (PD), to describe NPs and UFPs in the vapor stage of enclosed zones. The acquired extracts were analyzed by advanced electron microscopy techniques. A total of 392 NPs and 251 UFPs were examined in a set of 22 samples acquired in moderately limited or inadequately ventilated indoor areas from several schools. Noting that NPs-related disorders happen at particular places of respirational structure, identification of site-specific NPs accumulation should be anticipated in direction to better verify the corresponding human health outcomes resulting from respirable NPs.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar em Ambientes Fechados/análise , Nanopartículas/análise , Aerossóis/análise , Poluição do Ar/análise , Atmosfera , Criança , Cidades , Poeira , Monitoramento Ambiental/métodos , Gases , Humanos , Veículos Automotores , Tamanho da Partícula , Material Particulado/análise , Instituições Acadêmicas
5.
Chemosphere ; 262: 127784, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32777612

RESUMO

While several studies have investigated the potential impact of nanoplastics, proof of their occurrence in our global environment has not yet been demonstrated. In the present work, by developing an innovative analytical strategy, the presence of nanoplastics in soil was identified for the first time. Our results demonstrate the presence of nanoplastics with a size ranging from 20 to 150 nm and covering three of the most common plastic families: polyethylene, polystyrene and polyvinyl chloride. Given the amount of organic matter in the soil matrix, the discrimination and identification of large nanoplastic aggregates are challenging. However, we provided an innovative methodology to circumvent the organic matter impact on nanoplastic detection by coupling size fractionation to molecular analysis of plastics. While photodegradation has been considered the principal formation pathway of nanoplastics in the environment, this study provides evidence, for the first time, that plastic degradation and nanoplastic production can, however, occur in the soil matrix. Moreover, by providing an innovative and simple extraction/analysis method, this study paves the way to further studies, notably regarding nanoplastic environmental fate and impacts.


Assuntos
Monitoramento Ambiental/métodos , Microplásticos/análise , Nanopartículas/análise , Poluentes do Solo/análise , Solo/química , França , Tamanho da Partícula , Polietileno/análise , Poliestirenos/análise , Cloreto de Polivinila/análise
6.
J Sci Food Agric ; 101(2): 684-692, 2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32705699

RESUMO

BACKGROUND: Sulfamethazine (SMZ), a veterinary drug widely used in animal husbandry, is harmful to human health when excess residues are present in food. In this study, a fast, reliable, and sensitive immunochromatographic assay (ICA) was developed on the basis of the competitive format by using time-resolved fluorescent nanobeads (TRFN) as label for the detection of SMZ in egg, honey, and pork samples. RESULTS: Under optimized working conditions, this method had limits of detection of 0.016, 0.049, and 0.029 ng mL-1 and corresponding linear ranges of 0.05 to 1.00, 0.05 to 5.00, and 0.05 to 1.00 ng mL-1 in egg, honey, and pork samples, respectively. The recovery experiments showed that the average recoveries ranged from 90.5% to 113.9%, 82.4% to 112.0%, and 79.8% to 93.4% with corresponding coefficients of variation of 4.1% to 11.7%, 7.5% to 11.5%, and 4.8% to 8.7% for egg, honey, and pork samples, respectively. The developed TRFN-ICA was also systematically compared with high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) by analyzing 45 actual samples from egg, honey, and pork. CONCLUSION: Overall, the developed TRFN-ICA had high reliability and excellent potential for the ultrasensitive detection of SMZ for food safety monitoring, also providing a universal platform for the on-site detection of other targets. © 2020 Society of Chemical Industry.


Assuntos
Anti-Infecciosos/análise , Ovos/análise , Contaminação de Alimentos/análise , Mel/análise , Imunoensaio/métodos , Carne/análise , Sulfametazina/análise , Drogas Veterinárias/análise , Animais , Galinhas , Imunoensaio/instrumentação , Limite de Detecção , Nanopartículas/análise , Suínos
7.
J Sci Food Agric ; 101(2): 735-745, 2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32706118

RESUMO

BACKGROUND: Coated nano zinc oxide (Cnz) is a new feed or food additive, which is a potential replacement for a pharmacological dose level of ZnO. This study evaluated the positive effects of different concentrations of Cnz on the intestinal bacterial core, enterobacterial composition and mucosal barrier function in a pig model. RESULTS: Microbiota sequencing results showed that Cnz could significantly alter the intestinal microbiota composition and metabolism. Besides increasing the richness indices (ACE and Chao1), 10% Cnz could protect the intestinal mucosal barrier through increasing the expression of occludin and zonula occludens-1 in the small intestine, increase the abundance of Lachnospiraceae UCG-004 and decrease the abundance of Ruminococcus flavefaciens compared to high ZnO diet and 5% Cnz material. CONCLUSIONS: Cnz material at 10% supplementation is more effective than a level of 5% Cnz in increasing intestinal barrier through affecting gut microbiota. © 2020 Society of Chemical Industry.


Assuntos
Bactérias/efeitos dos fármacos , Fezes/microbiologia , Microbioma Gastrointestinal/efeitos dos fármacos , Óxido de Zinco/administração & dosagem , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Suplementos Nutricionais/análise , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/microbiologia , Nanopartículas/administração & dosagem , Nanopartículas/análise , Suínos , Óxido de Zinco/análise
8.
J Chromatogr A ; 1632: 461600, 2020 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-33091793

RESUMO

Aquatic ecosystems are facing multiple direct and indirect stressors from anthropogenic activities. Aquatic colloids, including natural and manufactured nanoparticles, have received global concern owing to their ability to transport metals, nutrients and pollutants, and their potential to pose ecological risks for wildlife and human health. Asymmetric flow-field flow fractionation (AF4) has become one of the most promising and powerful approaches to characterize colloidal particles over the last ten years. This review overviews the advances and applications of AF4 for the study of aquatic systems over the last decade. The analytical challenge of AF4 and known deviation from theoretical assumptions are also critically discussed, such as sample losses, membrane-analyte interactions, and overloading. Future needs for methodological advances are addressed.


Assuntos
Ecossistema , Fracionamento por Campo e Fluxo/métodos , Rios , Coloides/química , Nanopartículas/análise , Espectrometria de Fluorescência
9.
Chemosphere ; 254: 126794, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957267

RESUMO

Present study carried out pot experiments and evaluated effects of single and binary mixture of nanoparticles (exposed via sludge as soil conditioner) on spinach plant. Exposure of Ag2O nanoparticles (NPs) (1 and 10 mg/kg soil-sludge) did not show significant reduction in plant as compared to control. On the other hand, TiO2 NPs (exposed as single and in binary mixture) resulted in significant increase in root length (29% and 37%) and fresh weight (60% and 48%) at highest exposure concentration. Total chlorophyll content decreased for Ag2O and binary mixture (7% and 4%, respectively) and increased for TiO2 (5%) at 10 mg/kg soil-sludge. The toxic interaction between Ag2O and TiO2 NPs was additive at both exposure concentrations. Ag2O NPs had higher tendency of root surface adsorption than TiO2 NPs. Metal content in spinach leaves at highest exposure concentration was Ag: 2.6 ± 0.55 mg/g plant biomass(for Ag2O NPs) and 1.02 ± 0.32 mg/g plant biomass (for Ag2O + TiO2 NPs) and for Ti: 1.12 ± 0.78 (for TiO2 NPs) mg/g plant biomass and 0.58 ± 0.41 mg/g (for Ag2O + TiO2 NPs). The inadvertent ingestion of NPs- contaminated spinach resulted in projected daily intake (DI) of Ag and Ti for different age-mass classes (child to adult) exceeding the oral reference dose for toxicity during oral ingestion. In conclusion, we report no acute toxicity of single and binary mixture of NPs to spinach but significant accumulation of Ag and Ti metals in spinach leaves. There are high chances that ingestion of spinach grown in such environment might lead to human health risks.


Assuntos
Nanopartículas/toxicidade , Poluentes do Solo/toxicidade , Spinacia oleracea/efeitos dos fármacos , Biomassa , Clorofila , Humanos , Nanopartículas Metálicas/toxicidade , Metais/toxicidade , Nanopartículas/análise , Folhas de Planta/química , Esgotos , Solo , Poluentes do Solo/análise , Spinacia oleracea/crescimento & desenvolvimento , Titânio/farmacologia
10.
Chemosphere ; 254: 126822, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957270

RESUMO

Atmosphere contamination management is one of the most important features in pollution risk management. The worldwide rise in tourism increases apprehension about its probable destructive conservation influence on various aspects of global conservation. One of the principal dangers increased by tourism-based modes of travel are nanoparticles (NPs) containing potentially hazardous elements (PHEs) contamination. One example of this is island destination of Lanzarote, in Spain's Canary Islands in which we examined contamination of the local atmosphere, water and soil. Important NPs containing PHEs, (e.g. arsenic, chromium, lead, and mercury), were found in this locale. It is reasonable to assume that this pollution poses an increased environmental danger to the local biome(s). Modes of transport (i.e. by car, airplane, bus) were shown to be an important contributor to this localized contamination as demonstrated by particulate matter (PM) readings collected near the island's airport. If no measures are taken to reduce vehicle and aircraft traffic, the tendency is to increase environmental degradation will continue unabated. As this particular area of Lanzarote is also one of wine production, increased pollution has the potential for negative impacts on the region's economy.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Nanopartículas/análise , Material Particulado/análise , Emissões de Veículos/análise , Aeronaves , Aeroportos , Atmosfera , Ecossistema , Poluição Ambiental , Geologia , Ilhas , Solo , Espanha
11.
PLoS One ; 15(7): e0235988, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32726346

RESUMO

Titanium dioxide (TiO2) is a common component in personal care products (PCP), which through use enters the wastewater treatment plant (WWTP) and ultimately the environment. A citizen science approach is utilized here to inform the prevalence and usage of TiO2 containing PCP on a household scale, which generates information as to the quantity of TiO2 entering the WWTP, and the portion ultimately discharged to the environment. Meanwhile, citizen science sourced inventories were generated to estimate the quantity of TiO2, and potentially nanoscale TiO2 entering the WWTP from consumer products and to determine which products had the greatest contribution. The estimated values were compared with water samples from the WWTP which quantified the amount of total titanium present using ICP-AES. These values were at a similar level with other top-down estimation approaches and suggest that a citizen science approach is valid to estimate the loading of TiO2, and potentially other emerging contaminants, while at the same time engaging with community stakeholders.


Assuntos
Ciência do Cidadão/métodos , Cosméticos/análise , Nanopartículas/análise , Titânio/análise , Águas Residuárias/química , Poluentes Químicos da Água/análise , Humanos
12.
Artigo em Inglês | MEDLINE | ID: mdl-32475216

RESUMO

Zinc oxide nanoparticles (ZnO NPs) production and usage might lead to a large discharge of ZnO NPs into the natural environment, raising concerns of pollution and ecological security. The effects of ZnO NPs on waste activated sludge hydrolytic acidification and microbial communities were studied in semi-continuous fermentation systems. The fermentation performance of eight ZnO NPs concentrations including ZnO NPs normal [0.01, 0.1, 1 and 10 mg/g mixed liquor suspended solids (MLSS)] and ZnO NPs shock (10, 1000, 1000 and 10,000 mg/g MLSS) were discussed, and their biodegradability was also analyzed. The experimental results showed that proteins, polysaccharides and short-chain fatty acids were enhanced by ZnO NPs, particularly by ZnO NPs shock. Low ZnO NPs concentrations inhibited coenzyme 420 (F420) and dehydrogenase activities but enhanced α-glucosidase and protease activities. Illumina MiSeq sequencing revealed that ZnO NPs addition enriched Azospira, Ottowia and Hyphomicrobium but not Anaerolineaceae.


Assuntos
Fermentação , Microbiota/efeitos dos fármacos , Nanopartículas/toxicidade , Esgotos/microbiologia , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/toxicidade , Óxido de Zinco/toxicidade , Anaerobiose , Biodegradação Ambiental , Hidrólise , Nanopartículas/análise , Esgotos/química , Poluentes Químicos da Água/análise , Óxido de Zinco/análise
13.
J Vis Exp ; (159)2020 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-32510496

RESUMO

The current particle size threshold of the European Particle Number (PN) emission standards is 23 nm. This threshold could change because future combustion engine vehicle technology may emit large amounts of sub-23 nm particles. The Horizon 2020 funded project DownToTen (DTT) developed a sampling and measurement method to characterize particle emissions in this currently unregulated size range. A PN measurement system was developed based on an extensive review of the literature and laboratory experiments testing a variety of PN measurement and sampling approaches. The measurement system developed is characterized by high particle penetration and versatility, which enables the assessment of primary particles, delayed primary particles, and secondary aerosols, starting from a few nanometers in diameter. This paper provides instruction on how to install and operate this Portable Emission Measurement System (PEMS) for Real Drive Emissions (RDE) measurements and assess particle number emissions below the current legislative limit of 23 nm.


Assuntos
Condução de Veículo , Monitoramento Ambiental/métodos , Nanopartículas/análise , Nanopartículas/química , Tamanho da Partícula , Emissões de Veículos/análise , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/química , Monitoramento Ambiental/instrumentação , Laboratórios , Material Particulado/análise , Material Particulado/química
14.
Aquat Toxicol ; 224: 105481, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32380301

RESUMO

Modern nano-engineered pesticides have great promise for agriculture due to their extended, low dose release profiles that are intended to increase effectiveness but reduce environmental harm. Whether nanopesticides, including copper (Cu) formulations, cause reduced levels of toxicity to non-target aquatic organisms is unclear but important to assess. Predicting how aquatic species respond to incidental exposure to Cu-based nanopesticides is challenging because of the expected very low concentrations in the environment, and the two forms of exposure that may occur, namely to Cu ions and Cu nanoparticles. We conducted Cu speciation, tissue uptake, and 7-day toxicity laboratory experiments to test how a model estuarine organism, the amphipod Leptocheirus plumulosus, responded to two popular Cu-based nanopesticides, CuPRO and Kocide, and conventional CuCl2. Exposure concentrations ranged from 0 to 2.5 ppm, which were similar to those found in estuarine water located downstream of agricultural fields. Cu dissolution rates were much slower for the nanopesticides than the ionic formula, and Cu body burden in amphipods increased approximately linearly with the nominal exposure concentration. Amphipod survival declined in a normal dose-response manner with no difference among Cu formulations. Growth and movement rates after 7 days revealed no difference among exposure levels when analyzed with conventional statistical methods. By contrast, analysis of respiration rates, inferred from biomass measurements, with a bioenergetic toxicodynamic model indicated potential for population-level effects of exposure to very low-levels of the two nanopesticides, as well as the control contaminant CuCl2. Our results indicate that toxicity assessment of environmental trace pollutant concentrations may go undetected with traditional ecotoxicological tests. We present a process integrating toxicity test results and toxicodynamic modeling that can improve our capacity to detect and predict environmental impacts of very low levels of nanomaterials released into the environment.


Assuntos
Anfípodes/efeitos dos fármacos , Cobre/toxicidade , Estuários , Nanopartículas/toxicidade , Praguicidas/toxicidade , Poluentes Químicos da Água/toxicidade , Anfípodes/química , Animais , Carga Corporal (Radioterapia) , Cobre/análise , Relação Dose-Resposta a Droga , Nanopartículas/análise , Praguicidas/análise , Água do Mar/química , Poluentes Químicos da Água/análise
15.
Nanomedicine (Lond) ; 15(15): 1501-1512, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32378459

RESUMO

Nanotechnology and nanomedicine have excellent potential in dealing with a range of different health problems, including viruses, which are considered to be a serious challenge in the medical field. Application of nanobiotechnology could represent a new avenue for the treatment or disinfection of viruses. There is increasing concern regarding the control of coronaviruses, among these, Middle East respiratory syndrome coronavirus, severe acute respiratory syndrome coronavirus and severe acute respiratory syndrome coronavirus-2 are well known and dangerous examples. This article aims to provide an overview of recent studies on the effectiveness of nanoparticles as diagnostic or antiviral tools against coronaviruses. The possibilities of effectively using nanomaterials as vaccines and nanosensors in this field are also presented.


Assuntos
Antivirais/uso terapêutico , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/terapia , Nanopartículas/uso terapêutico , Animais , Antivirais/análise , Técnicas Biossensoriais/métodos , Coronavirus/efeitos dos fármacos , Coronavirus/isolamento & purificação , Infecções por Coronavirus/prevenção & controle , Humanos , Nanomedicina/métodos , Nanopartículas/análise , Nanotecnologia/métodos , Pandemias/prevenção & controle , Pneumonia Viral/diagnóstico , Pneumonia Viral/prevenção & controle , Pneumonia Viral/terapia
16.
Nat Nanotechnol ; 15(6): 482-490, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32451501

RESUMO

Distance-dependent magnetic resonance tuning (MRET) technology enables the sensing and quantitative imaging of biological targets in vivo, with the advantage of deep tissue penetration and fewer interactions with the surroundings as compared with those of fluorescence-based Förster resonance energy transfer. However, applications of MRET technology in vivo are currently limited by the moderate contrast enhancement and stability of T1-based MRET probes. Here we report a new two-way magnetic resonance tuning (TMRET) nanoprobe with dually activatable T1 and T2 magnetic resonance signals that is coupled with dual-contrast enhanced subtraction imaging. This integrated platform achieves a substantially improved contrast enhancement with minimal background signal and can be used to quantitatively image molecular targets in tumours and to sensitively detect very small intracranial brain tumours in patient-derived xenograft models. The high tumour-to-normal tissue ratio offered by TMRET in combination with dual-contrast enhanced subtraction imaging provides new opportunities for molecular diagnostics and image-guided biomedical applications.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Meios de Contraste/análise , Glioma/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Nanopartículas/análise , Animais , Encéfalo/diagnóstico por imagem , Humanos , Aumento da Imagem/métodos , Camundongos , Micelas , Nanotecnologia/métodos
17.
Nat Commun ; 11(1): 2567, 2020 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-32444803

RESUMO

Ambient particulate matter pollution is one of the leading causes of global disease burden. Epidemiological studies have revealed the connections between particulate exposure and cardiovascular and respiratory diseases. However, until now, the real species of ambient ultrafine particles (UFPs) in humans are still scarcely known. Here we report the discovery and characterization of exogenous nanoparticles (NPs) in human serum and pleural effusion (PE) samples collected from non-occupational subjects in a typical polluted region. We show the wide presence of NPs in human serum and PE samples with extreme diversity in chemical species, concentration, and morphology. Through chemical multi-fingerprinting (including elemental fingerprints, high-resolution structural fingerprints, and stable iron isotopic fingerprints) of NPs, we identify the sources of the NPs to be abiogenic, particularly, combustion-derived particulate emission. Our results provide evidence for the translocation of ambient UFPs into the human circulatory system, and also provide information for understanding their systemic health effects.


Assuntos
Material Particulado/análise , Material Particulado/química , Derrame Pleural/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Feminino , Humanos , Ferro/análise , Pneumopatias/sangue , Pneumopatias/patologia , Masculino , Metais/análise , Camundongos , Microscopia Eletrônica de Transmissão , Pessoa de Meia-Idade , Nanopartículas/análise , Nanopartículas/química , Tamanho da Partícula , Material Particulado/sangue , Material Particulado/toxicidade , Células RAW 264.7 , Espectrometria por Raios X
18.
Nat Commun ; 11(1): 1653, 2020 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-32245962

RESUMO

Particulate matter (PM) pollutants, including nanoscale particles (NPs), have been considered serious threats to public health. In this work, a self-powered air filter that can be used in high-efficiency removal of PM, including NPs, is presented. An ionic liquid-polymer (ILP) composite is irregularly distributed onto a sponge network to form an ILP@MF filter. Enabled by its unique electrochemical properties, the ILP@MF filter can remove PM2.5 and PM10 with high efficiencies of 99.59% and 99.75%, respectively, after applying a low voltage. More importantly, the charged ILP@MF filter realizes a superior removal for NPs with an efficiency of 93.77%. A micro-button lithium cell or silicon-based solar panel is employed as a power supply platform to fabricate a portable and self-powered face mask, which exhibits excellent efficacy in particulate removal compared to commercial masks. This work shows a great promise for high-performance purification devices and facile mask production to remove particulate pollutants.


Assuntos
Filtros de Ar , Recuperação e Remediação Ambiental/métodos , Material Particulado/análise , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Nanopartículas/análise
19.
Nat Nanotechnol ; 15(6): 500-506, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32313220

RESUMO

Capturing the dynamics of live cell populations with nanoscale resolution poses a significant challenge, primarily owing to the speed-resolution trade-off of existing microscopy techniques. Flow cytometry would offer sufficient throughput, but lacks subsample detail. Here we show that imaging flow cytometry, in which the point detectors of flow cytometry are replaced with a camera to record 2D images, is compatible with 3D localization microscopy through point-spread-function engineering, which encodes the depth of the emitter into the emission pattern captured by the camera. The extraction of 3D positions from sub-cellular objects of interest is achieved by calibrating the depth-dependent response of the imaging system using fluorescent beads mixed with the sample buffer. This approach enables 4D imaging of up to tens of thousands of objects per minute and can be applied to characterize chromatin dynamics and the uptake and spatial distribution of nanoparticles in live cancer cells.


Assuntos
Citometria de Fluxo/instrumentação , Microscopia de Fluorescência/instrumentação , Imagem Óptica/instrumentação , Desenho de Equipamento , Humanos , Imageamento Tridimensional/instrumentação , Nanopartículas/análise , Saccharomyces cerevisiae/citologia , Linfócitos T/citologia
20.
Food Chem ; 319: 126579, 2020 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-32193061

RESUMO

Food processing generates a large amount of self-assembled colloidal nanoparticles (NPs), which have defined structures and directly interact with macrophages. Their promising potential as a new source of functional NPs and a key to elucidate food-body interactions prompt the importance of the method development. This study attempts to apply capillary zone electrophoresis (CZE) in studying self-assembled nanoparticles in a real liquid food system of freshwater clam (Corbicula fluminea) soup, a popular delicacy in East Asia with proven hepatoprotective effects. The soup sample was satisfactorily separated into one nanoparticle fraction and multiple molecular fractions within five minutes by the single and rapid CZE analysis, which was of high repeatability (peak area RSD < 4%, migration time RSD < 1%) and accurate quantification with a linear area-number relationship in the range of (7.5-110) × 1011 particles/mL (R2 > 0.99). Therefore, CZE analysis can be an efficient tool for the investigation of self-assembled nanoparticles in real liquid food systems.


Assuntos
Eletroforese Capilar/métodos , Análise de Alimentos/métodos , Nanopartículas/análise , Frutos do Mar/análise , Animais , Corbicula/química , Nanopartículas/química , Reprodutibilidade dos Testes
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...