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1.
Nano Lett ; 24(1): 130-139, 2024 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-38150297

RESUMEN

Photothermal immunotherapy has become a promising strategy for tumor treatment. However, the intrinsic drawbacks like light instability, poor immunoadjuvant effect, and poor accumulation of conventional inorganic or organic photothermal agents limit their further applications. Based on the superior carrying capacity and active tumor targeting property of living bacteria, an immunoadjuvant-intensified and engineered tumor-targeting bacterium was constructed to achieve effective photothermal immunotherapy. Specifically, immunoadjuvant imiquimod (R837)-loaded thermosensitive liposomes (R837@TSL) were covalently decorated onto Rhodobacter sphaeroides (R.S) to obtain nanoimmunoadjuvant-armed bacteria (R.S-R837@TSL). The intrinsic photothermal property of R.S combined R837@TSL to achieve in situ near-infrared (NIR) laser-controlled release of R837. Meanwhile, tumor immunogenic cell death (ICD) caused by photothermal effect of R.S-R837@TSL, synergizes with released immunoadjuvants to promote maturation of dendritic cells (DCs), which enhance cytotoxic T lymphocytes (CTLs) infiltration for further tumor eradication. The photosynthetic bacteria armed with immunoadjuvant-loaded liposomes provide a strategy for immunoadjuvant-enhanced cancer photothermal immunotherapy.


Asunto(s)
Nanopartículas , Neoplasias , Rhodobacter sphaeroides , Humanos , Adyuvantes Inmunológicos , Liposomas , Imiquimod , Neoplasias/patología , Inmunoterapia , Línea Celular Tumoral , Fototerapia
2.
J Clin Periodontol ; 51(2): 196-208, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38088448

RESUMEN

AIM: To reveal the cellular composition and molecular environment of the periodontal and peri-implant inflammatory infiltrates through a single-cell sequencing technique, which may explain the pathological difference between these two diseases. A special focus was placed on the phenotypes and potential roles of neutrophils and fibroblasts in peri-implant/periodontal tissue immunity. MATERIALS AND METHODS: High-throughput single-cell transcriptomic profiling of peri-implant tissues from patients with peri-implantitis as well as periodontal tissues from patients with periodontitis and healthy donors was performed. Immunofluorescence analysis was carried out to further validate the identified cell subtypes and their involvement in peri-implantitis and periodontitis. RESULTS: Based on our single-cell resolution analysis, a quantified proportional increase of neutrophil (Neu) subtypes was shown in peri-implantitis. Among these, a predominance of Neutro_CXCR2 was revealed. We also found the involvement of inflammation-promoting fibroblasts as well as a predominance of CXCL8+ fibroblast-CXCR2+ neutrophil interaction in peri-implantitis. CONCLUSIONS: Our study indicated that the predominance of CXCL8+ fibroblast-CXCR2+ neutrophil interaction might underline the enhanced host response in peri-implantitis compared with periodontitis. This information offers a molecular basis by which fibroblast and neutrophil subtypes might be diagnostically and therapeutically targeted in peri-implantitis.


Asunto(s)
Implantes Dentales , Periimplantitis , Periodontitis , Humanos , Neutrófilos , Inflamación , Periodontitis/patología , Fibroblastos
3.
Artículo en Inglés | MEDLINE | ID: mdl-38526576

RESUMEN

PURPOSE: This large retrospective, single-center, follow-up study investigated the endoscopic prelacrimal recess approach (PLRA) for treating maxillary sinus inverted papilloma (MSIP). METHODS: Between January 2007 and November 2022, patients with MSIP treated with PLRA were enrolled. Data on clinical manifestations, imaging, and surgical procedures were collected. The visual analog scale (VAS) scores for maxillofacial numbness and nasal symptoms and the SNOT-22 nasal symptom scores were statistically analyzed. RESULT: Of 122 patients (68 males and 54 females) enrolled in the study, with a mean age of 50.75 ± 12.84 years (26-80 years), 111 patients underwent PLRA, nine underwent modified PLRA, one converted to an endoscopic medial maxillectomy (EMM), and one to an endoscopic modified Denker's approach. The average follow-up was 86.60 (13-192) months, the recurrence rate was 3.28%, and 29 patients (23.77%) complained of maxillofacial numbness one month postoperatively, which disappeared in most cases one year after surgery. Five patients (4.10%) experienced mild numbness at the end of the follow-up period. Maxillary sinus ostium contracture or atresia occurred in two cases (1.64%). After surgery, the VAS nasal symptom scores improved significantly (P < 0.001). SNOT-22 indicated that the most common postoperative symptom was thick nasal discharge. CONCLUSION: PLRA is a flexible first-choice surgical treatment for maxillary sinus inverted papilloma and can be modified according to the extent of the lesion, the surgeon's experience and technique, and surgical instruments. That can help achieve complete resection and reduce recurrence and surgical complications. Upper teeth numbness, the most common postoperative complication, tends to disappear after 1 year.

4.
Environ Sci Technol ; 57(50): 21005-21015, 2023 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-38048287

RESUMEN

Crumb rubber (CR) is a commonly used infill material in artificial turf worldwide. However, the potential health risk associated with exposure to CR containing environmentally persistent free radicals (EPFRs) remains under investigation. Herein, we observed the widespread presence of CR particles in the range of 2.8-51.4 µg/m3 and EPFRs exceeding 6 × 1015 spins/g in the ambient air surrounding artificial turf fields. Notably, the abundance of these particles tended to increase with the number of operating years of the playing fields. Furthermore, by analyzing saliva samples from 200 participants, we established for the first time that EPFR-carrying CR could be found in saliva specimens, suggesting the potential for inhaling them through the oral cavity and their exposure to the human body. After 40 min of exercise on the turf, we detected a substantial presence of EPFRs, reaching as high as (1.15 ± 1.00) × 1016 spins of EPFR per 10 mL of saliva. Moreover, the presence of EPFRs considerably increased the oxidative potential of CR, leading to the inactivation of Ca2+, redox reactions, and changes in spatial binding of the α-1,4-chain of salivary amylase to Ca2+, all of which could influence human saliva health. Our study provides insights into a new pathway of human exposure to CR with EPFRs in artificial turf infill, indicating an increased human health risk of CR exposure.


Asunto(s)
Exposición a Riesgos Ambientales , Goma , Humanos , Exposición a Riesgos Ambientales/análisis , Saliva , Radicales Libres
5.
Mikrochim Acta ; 190(11): 447, 2023 10 21.
Artículo en Inglés | MEDLINE | ID: mdl-37864774

RESUMEN

Flexible silver substrates were made by in situ reduction of silver nanoparticles in bacterial cellulose membranes using the unique advantage of dopamine. Subsequently, we modified the substrate with 4-mercaptophenol (4-MP), a molecule capable of specifically recognizing ClO-, and its corresponding SERS signal changes with the concentration of hypochlorite, thus allowing the quantitative detection of ClO- content. The method showed a negative linear correlation (R2 = 0.9567) with the SERS intensity at 1077 cm-1 over the concentration range 0.5-100 µM, and the detection limit was 0.15 µM. The RSD of the SERS intensity at 1077 cm-1 under five batches was 4.2%, which proved the good reproducibility of P-BCM-Ag NP-MP. Finally, the P-BCM-Ag NPs were used for the detection of hypochlorite in cell contents, artificial urine, and clinical serum samples, utilizing spike experiments in all three environments. The recoveries were in the range 90-110% indicating the accuracy of the method for the detection of hypochlorite and validating the promising application of this assay for practical detection in intricate biological samples.


Asunto(s)
Celulosa , Nanopartículas del Metal , Dopamina , Ácido Hipocloroso , Plata/química , Nanopartículas del Metal/química , Reproducibilidad de los Resultados , Espectrometría Raman/métodos
6.
Molecules ; 27(19)2022 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-36235099

RESUMEN

In order to understand the basic situation of pesticide residues in vegetables in China's porcelain capital, four kinds of common vegetables on the market were selected in this study for detection and analysis of pesticide residues. The pesticide residues in vegetables were analyzed through sample selection, optimization of instrument and equipment conditions, and comparison of detection pass rates. The sampling locations were common vegetables purchasing places such as large and medium-sized supermarkets. QuEChERS method was used as the sample pretreatment, and gas chromatography (GC-MS/MS) was used for quantitative analysis. Finally, the exposure risk of pesticides was assessed according to the test results. The results showed that all the pesticides were detected in four kinds of vegetables, but the detected pesticides did not exceed the national standard (GB 2763-2014, China). Moreover, the target risk coefficient (THQ) and risk index (HI) values of four vegetables were less than one, indicating that the combined and toxic effect of pesticide residual mixed contamination was smaller in four vegetables. Therefore, there was no significant harm from people using these vegetables.


Asunto(s)
Residuos de Plaguicidas , Plaguicidas , Porcelana Dental , Exposición Dietética/análisis , Contaminación de Alimentos/análisis , Frutas/química , Cromatografía de Gases y Espectrometría de Masas/métodos , Humanos , Residuos de Plaguicidas/análisis , Plaguicidas/análisis , Medición de Riesgo , Espectrometría de Masas en Tándem/métodos , Verduras/química
7.
Nanomedicine ; 25: 102167, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32006685

RESUMEN

The application of photodynamic therapy (PDT) is of ever-increasing importance in the treatment of malignant tumors; however, there are several major constraints that make it impossible to achieve optimal therapeutic effects. Our objective is to develop a novel photosensitizing drug for skin cancer. In the experiment, we fabricated four-arm-poly ethylene glycol modified amino-rich graphite phase carbon nitride nanosheets (AGCN-PEG), which have good stability in physiological solution and show selective accumulation in tumor cells. Under hypoxic conditions, the AGCN-PEG induced PDT can effectively inhibit growth on A431 human epidermoid carcinoma cells in vivo and in vitro. What's more, after being combined with TMPyP4, the therapeutic effect of AGCN-PEG was greatly improved.


Asunto(s)
Nanoestructuras/química , Neoplasias/terapia , Fotoquimioterapia , Fármacos Fotosensibilizantes/farmacología , Línea Celular Tumoral , Grafito/química , Humanos , Neoplasias/patología , Nitrilos/química , Nitrilos/farmacología , Fármacos Fotosensibilizantes/síntesis química , Fármacos Fotosensibilizantes/química , Polietilenglicoles/química , Polietilenglicoles/farmacología , Especies Reactivas de Oxígeno/química , Hipoxia Tumoral/efectos de los fármacos
8.
Prep Biochem Biotechnol ; 47(10): 1025-1031, 2017 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-28857665

RESUMEN

Biomass acid hydrolysate of oleaginous yeast Trichosporon cutaneum after microbial oil extraction was applied as substrate for bacterial cellulose (BC) production by Komagataeibacter xylinus (also named as Gluconacetobacter xylinus previously) for the first time. BC was synthesized in static culture for 10 days, and the maximum BC yield (2.9 g/L) was got at the 4th day of fermentation. Most carbon sources in the substrate (glucose, mannose, formic acid, acetic acid) can be utilized by K. xylinus. The highest chemical oxygen demand (COD) removal (40.7 ± 3.0%) was obtained at the 6th day of fermentation, and then the COD increased possibly due to the degradation of BC. The highest BC yield on COD consumption was 38.7 ± 4.0% (w/w), suggesting that this is one efficient bioconversion for BC production. The BC structure was affected little by the substrate by comparison with that generated in classical HS medium using field-emission scanning electron microscope (FE-SEM), Fourier transform infrared, and X-ray diffraction. Overall, this technology can both solve the issue of waste oleaginous yeast biomass and produce valuable biopolymer (BC).


Asunto(s)
Biomasa , Celulosa/metabolismo , Gluconacetobacter xylinus/metabolismo , Microbiología Industrial/métodos , Aceites/aislamiento & purificación , Trichosporon/metabolismo , Ácidos/metabolismo , Análisis de la Demanda Biológica de Oxígeno , Fermentación , Hidrólisis , Aceites/metabolismo , Residuos Sólidos/análisis , Trichosporon/química
9.
Int J Biol Macromol ; 263(Pt 1): 130291, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38378119

RESUMEN

In abdominal wall defect repair, surgical site infection (SSI) remains the primary cause of failure, while complications like visceral adhesions present significant challenges following patch implantation. We designed a Janus multifunctional hydrogel patch (JMP) with antibacterial, anti-inflammatory, and anti-adhesive properties. The patch comprises two distinct layers: a pro-healing layer and an anti-adhesion layer. The pro-healing layer was created by a simple mixture of polyvinyl alcohol (PVA), quaternized chitosan (QCS), and gallic acid (GA), crosslinked to form PVA/QCS/GA (PQG) hydrogels through GA's self-assembly effect and hydrogen bonding. Additionally, the PVA anti-adhesive layer was constructed using a drying-assisted salting method, providing a smooth and dense physical barrier to prevent visceral adhesion while offering essential mechanical support to the abdominal wall. The hydrogel patch demonstrates widely adjustable mechanical properties, exceptional biocompatibility, and potent antimicrobial properties, along with a sustained and stable release of antioxidants. In rat models of skin and abdominal wall defects, the JMP effectively promoted tissue healing by controlling infection, inhibiting inflammation, stimulating neovascularization, and successfully preventing the formation of visceral adhesions. These compelling results highlight the JMP's potential to improve the success rate of abdominal wall defect repair and reduce surgical complications.


Asunto(s)
Pared Abdominal , Quitosano , Ratas , Animales , Hidrogeles/farmacología , Alcohol Polivinílico , Ácido Gálico , Pared Abdominal/cirugía , Antibacterianos/farmacología , Adhesivos , Adherencias Tisulares/prevención & control
10.
Water Res ; 229: 119431, 2023 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-36527870

RESUMEN

The widespread presence of microplastics (MPs) in the Yangtze River, the third longest river in the world, has drawn increasing attention. Although numerous studies have been conducted recently to investigate and analyze the MPs exposure to the surface water of the river, most merely focus on a certain part of the Yangtze River, and knowledge of MPs based on the basin-wide is still scattered. This article reveals the spatial distribution characteristics of MPs in the Yangtze River from the whole watershed scale. Among the five areas in the basin, the upstream and the midstream were demonstrated to contain more MPs (3598.6 particles/m3 and 3226.8 particles/m3). The obtained results suggested the MP presented in the entire watersheds was uneven and the 'hotspots' occurred, where the MPs concentrations were relatively higher than the surrounding. The discharging of the wastewater treatment plants along the river, the locations of dams, and the stability and fragment of MPs, were demonstrated to be the important driving factors in the spatial distribution of MPs and leading to the appearance of the MP 'hotspots' in the Yangtze River, but were previously overlooked. It is the first study to evaluate the ecological risk of MPs exposure to the surface water of the Yangtze River with multiple assessment methods, taking not only abundance but also morphological characteristics, polymer composition and toxic effect into account. More importantly, based on the multiple individual MPs risk assessment methods, we developed the BetaMP method which achieves a comprehensive assessment of MP risk in basin-wide by taking multiple MP characteristics into account for the first time. This is conducive to better understanding the environmental impacts of MPs pollution in the different regions of the river.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Plásticos , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente/métodos , Ríos , Agua , Medición de Riesgo , China
11.
Int Dent J ; 73(3): 377-386, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36244799

RESUMEN

OBJECTIVES: Dental pulp stem cells (DPSCs) are a type of mesenchymal stem cell possessing self-renewal and multilineage differentiation capabilities. The dysfunction of DPSCs is related to the pathologic process of pulpitis. The participation of circular RNAs (circRNAs) in DPSC differentiation has been identified. This work focussed on exploring the functions and mechanism of circFKBP5 in DPSC dysfunction evoked by lipopolysaccharide (LPS). MATERIALS AND METHODS: The viability and apoptosis of human DPSCs (hDPSCs) were determined using Cell Counting Kit-8 assay and flow cytometry. Inflammation was analysed by measuring the release of inflammatory cytokines. The osteogenic differentiation of hDPSCs was investigated by performing alkaline phosphatase (ALP) staining and alizarin red S staining and detecting the changes of ALP and runt-related transcription factor 2 (RUNX2) proteins. The dual-luciferase reporter, RNA immunoprecipitation (RIP), and pull-down assays were used to confirm the binding between miR-708-5p and circFKBP5 or G-protein-coupled receptor (GPCR)-kinase interacting protein 2 (GIT2). RESULTS: CircFKBP5 expression was decreased in hDPSCs and, functionally, reexpression of circFKBP5 attenuated LPS-induced apoptosis, inflammation, and inhibition of proliferation ability and osteogenic differentiation in hDPSCs. Mechanistically, circFKBP5 acted as a sponge for miR-708-5p, which was verified to target GIT2. LPS induced miR-708-5p expression in hDPSCs, and knockdown of miR-708-5p protected against LPS-evoked hDPSC dysfunction. Besides, GIT2 expression was decreased in hDPSCs after LPS treatment. Rescue experiments showed that GIT2 could mediate the protective functions of circFKBP5 on hDPSCs under LPS treatment. CONCLUSIONS: CircFKBP5 could protect against LPS-induced apoptosis, inflammation, and osteogenic differentiation inhibition in hDPSCs via the miR-708-5p/GIT2 axis.


Asunto(s)
MicroARNs , Osteogénesis , Humanos , Osteogénesis/fisiología , Pulpa Dental/metabolismo , Lipopolisacáridos/farmacología , Lipopolisacáridos/metabolismo , Células Madre/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Inflamación/metabolismo , Diferenciación Celular/fisiología , Apoptosis
12.
J Hazard Mater ; 445: 130420, 2023 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-36462237

RESUMEN

Intensive application of low-density polyethylene mulch films has resulted in substantial accumulation of residual plastics in agricultural soil. Although considerable concerns have been raised on the residual plastic pollution, their impacts on the soil-rhizosphere microbe-plant ecosystem have not been fully elucidated. In this study, we used a pot experiment to determine the effects of residual plastic films with different sizes (La, Ma, Mi and Mx) on properties, enzyme systems and nutrients of soil, composition of rhizosphere microbial community, and physiology, growth and stress response of rice plants. Residual plastic films significantly decreased soil bulk density and increased soil porosity, leading to the alteration of extracellular enzyme activities, and accumulation of dissolved nitrogen (NO3-N + NH4-N). The structures of both bacterial and fungal communities were significantly changed by residual plastic films with rhizosphere microbes more sensitive to small-sized plastics. Plant growth was inhibited to different extents by residual plastic films with different sizes. The weighted gene co-expression network analysis (WGCNA) showed that photosynthesis and carbon fixation of rice plants were repressed by residual plastic films, due to the reduced chlorophyll content and rubisco activity. In addition, the endogenous jasmonic acid and antioxidant enzyme system were induced to activate tolerant responses in rice plants to the stress imposed by residual plastic films. The partial least squares path models (PLS-PMs) revealed that residual plastic films had direct and/or indirect effects on the soil-rhizosphere microbe-plant system.


Asunto(s)
Microbiota , Oryza , Suelo/química , Rizosfera , Ecosistema , Plásticos , Microbiología del Suelo , Plantas
13.
Environ Sci Pollut Res Int ; 30(25): 67854-67864, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37119489

RESUMEN

The pollution of freshwater environments with microplastics (MPs) has attracted increasing attention owing to their threats to aquatic ecosystems and human health. Here, we sampled and analyzed MPs from mainstream, tributary, and backwater areas in the Wanzhou section of the Three Gorges Reservoir (TGR) in impoundment and flood periods. Microplastic pollution was the most severe in the backwater areas. The average abundance of MPs reached the highest value in the flood period (5.27±3.47×107 items km-2), which was 3-5 times that in the impoundment period. In the 0.3-5 mm size class, the 1-5 mm fraction was the most abundant, accounting for more than 81% in the flood period and 68% of the total MP particle abundance in the impoundment period in the mainstream and backwater areas. However, 0.3-1 mm MPs contributed more than 50% in the tributaries during the impoundment period. Polystyrene, polypropylene, and polyethylene MPs were detected in foam, fragment, sheet, and line-shaped MP particles. White, opaque, foamed polystyrene MPs contributed 32-81% to total MP particle abundance in the watershed. Microplastic particle surfaces showed signs of damage and oxidation, and ten different elements were found. Oxygen was clustered on the surface of foam and fragment MPs. Microplastic pollution was severe in the Wanzhou watershed. Especially in the backwater areas, oxidized MPs of variable shapes derived mainly from surface runoff in the flood period and sewage discharge in the impoundment period were abundant. The results of this study contribute to understanding seasonal pollution patterns and surface characteristics of MPs in the TGR and similar watersheds.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Humanos , Plásticos , Agua , Ecosistema , Poliestirenos , Estaciones del Año , Monitoreo del Ambiente , Contaminantes Químicos del Agua/análisis , China
14.
Sci Total Environ ; 817: 153006, 2022 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-35016924

RESUMEN

Microplastics (MPs) pollution in the aquatic environment raises considerable concerns. Freshwater system is generally considered as an important source for MPs transformation into the marine environment, however, only limited data on the MPs pollution in global freshwater systems is available at this time. In this study, we explored the abundance, characteristics and distribution of microplastics in the Scheldt River. The investigation results indicated that the abundance of microplastics in sediments (15-413 items/kg dry weight (DW)) was much higher than that in surface water (0-113 items/m3), and small size MPs (less than 500 µm) frequently appeared in sediments. Industrial activities were regarded as the major cause of MP discharging. Risk assessment models with using data of the concentration of MPs, polymer types and toxicity of MPs exposure were developed to assess the risk of MPs pollution in both surface water and sediment of the Westerscheldt estuary. Risk assessment results revealed that MPs exposure have potentially adverse effects on the aquatic ecosystem and human health. MPs tend to be transported from "Hotspots", such as urban or industries area, to remote areas. The risk assessment of MPs serves as a baseline for better understanding the distribution and characteristics of MPs and highlights the need of intensively monitoring to limit MPs release by intensively monitoring. This research provides a perspective on the risk of MPs that could be used in future studies.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Ecosistema , Monitoreo del Ambiente/métodos , Estuarios , Sedimentos Geológicos , Humanos , Microplásticos/toxicidad , Plásticos , Medición de Riesgo , Contaminantes Químicos del Agua/análisis
15.
Sci Total Environ ; 851(Pt 2): 158167, 2022 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-35998719

RESUMEN

Microplastic (MP) exposure in the environment has been commonly demonstrated to have adverse effects on human health. The majority of studies on MP were related to the aquatic and terrestrial systems, its potential risk for ecosystem and human health when exposed to the atmosphere is not well-understood. The presented study, taking Xi'an, a megacity in Northwest China, as an example, first estimated the possibility of local residents bearing MPs pollution. The results figured out an average abundance of MPs in TSP, PM10, and PM2.5 was 12.5, 3.5 and 0.8 particles/L, respectively. A total of 15 polymer types of MPs were identified in the atmosphere. Although a species sensitivity distribution (SSD) approach is acknowledged to be useful to estimate the potential risk of pollutants, the result of SSD when used to evaluate the risk of MPs is debatable. In this study, SSD-based risk assessment showed that the atmospheric MP pollution in Xi'an had not yet reached the level of threatening human. However, unlike chemicals, it is unreliable to assess risk using the relationship of dose-response for MPs because toxic effects of MPs can be influenced by not only the abundance but also the characteristics, e.g., morphological size, shape and oxidative potential. Since insufficient mechanistic understanding regarding the relative relationship between MP characteristics and their toxic effects and limitation of the quality and relevance of toxicity data, the uncertainty of risk assessment of the atmospheric MPs is inevitable and the risk of the atmospheric MPs was tended to be underestimated. This poses a challenge to manufacturers and public health authorities, as well as researchers alike, however, we are already being exposed to the atmospheric MPs.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Humanos , Plásticos/toxicidad , Ecosistema , Incertidumbre , Monitoreo del Ambiente , Contaminantes Químicos del Agua/análisis , Atmósfera , China , Material Particulado/toxicidad
16.
Environ Pollut ; 310: 119880, 2022 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-35932900

RESUMEN

Land-use types may affect soil aggregates' stability and organic carbon (OC) distribution characteristics, but little is known about the effects on the distribution characteristics of microplastics (MPs) in the aggregates. Hence, the MPs abundance of soil aggregates and analyzed aggregates' stability, composition, and OC content from two soil layers of four land-use types in Gansu Province were investigated in this study. The total MPs abundances in woodland, farmland (wheat, maize, and potato), orchard, and intercropping (potato + apple orchard) of top and deep soils were 1383.3 and 1477.9, 1324.6 and 931.1, 1757.1 and 1930.9, 2127.2 and 1998.0, 1335.9 and 886.7, and 1777.5 and 1683.3 items kg-1, respectively. The largest MPs abundance was detected in the >5 mm fractions of topsoil in potato (3077.3 items kg-1), followed by maize (3044.7 items kg-1) and intercropping (2718.4 items kg-1). In the topsoil, the total MPs abundance increased significantly with decreasing aggregate stability, and also was positively correlated with bulk density, microbial biomass, and total nitrogen contents of bulk soil. Summarizing, the abundance distribution of MPs correlates with the soil aggregate characteristics of the different land-use types.


Asunto(s)
Microplásticos , Suelo , Agricultura , Carbono , China , Plásticos , Zea mays
17.
Huan Jing Ke Xue ; 43(10): 4430-4439, 2022 Oct 08.
Artículo en Zh | MEDLINE | ID: mdl-36224129

RESUMEN

In order to explore the distribution of microplastics in the freshwater environment of Qinghai-Tibet Plateau, 63 surface water samples were collected in Huangshui River basin of Qinghai province during the wet season, and the distribution characteristics and main influencing factors of microplastics in the surface water were analyzed by means of metallographic microscope, Fourier infrared spectroscopy, field investigation, and image data analysis. The potential ecological risks of microplastics were evaluated using risk index (H) and pollution load index (PLI) models. The abundance of microplastics in surface water ranged from 665-8780 n·m-3, with the highest average abundance of 5414 n·m-3 in Huangyuan County. The abundance of microplastics increased from upstream to downstream. The main colors of microplastics were transparent (67%) and black (17%), and the particle size was less than 50 µm (70%). Polyethylene (66%) and polypropylene (12%) were the main polymer types. The abundance of microplastics was positively correlated with cultivated land area, precipitation, and ultraviolet intensity, but the opposite results were observed in dissolved oxygen, redox potential, and wind speed. Additionally, the potential ecological risk of surface water in the Huangshui River basin was relatively low.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Monitoreo del Ambiente/métodos , Oxígeno/análisis , Plásticos/análisis , Polietileno/análisis , Polipropilenos/análisis , Agua/análisis , Contaminantes Químicos del Agua/análisis
18.
Environ Pollut ; 301: 119019, 2022 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-35189297

RESUMEN

A large amount of disposable plastic face masks (DPFs) is produced and used during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, which results in an inevitable consequence of the dramatic increase of DPFs waste. However, the impact of DPFs exposure to the environment on their toxicity is rarely considered. In this study, a range of 76-276 items/L microplastics (MPs) was detected in the DPFs leachates, and fibrous (> 80.3%) and polypropylene (PP, > 89.2%) MPs were dominant. Co, Cu, Ni, Sr, Ti and Zn, were commonly detected in all leachates of the tested DPFs. Organics, such as acetophenone, 2,4-Di-tert-butylphenol, benzothiazole, bisphenol-A and phthalide, were found in the DPFs leachate, which were including organic solvents and plasticizer. Besides, we first found an emerging environmental risk substance, namely environmentally persistent free radicals (EPFRs), was generated in the DPFs leachates. The characteristic g-factors of the EPFRs was in a range of 2.003-2.004, identified as mixture of carbon- and oxygen-centered radicals. By means of in vitro toxicity assay, the DPFs leachate were confirmed to cause cytotoxicity and oxidative stress. Significantly, it is found that the formed EPFRs could contribute more toxic effects. Furthermore, when compared to N95 respirators, the tested surgical masks tend to release more MPs, leach more metals and organics, and generate more EPFRs. Surgical masks were thus showed higher risk than N95 respirators after exposure to water. This work highlights the importance of understanding the chemical complexity and possible toxicity of DPFs for their risk assessment.


Asunto(s)
COVID-19 , Máscaras , Radicales Libres , Humanos , Pandemias , Plásticos , SARS-CoV-2
19.
Chemosphere ; 307(Pt 4): 136094, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35995200

RESUMEN

Polystyrene (PS) is selected as a representative nanoplastic and persistent pollutant for its difficult degradation and wide application. The environmental risk assessment of PS is obstructed by the toxic dye-based fluorescent PS, which false positives could be induced by the leakage of dye. For high biocompatibility, low toxicity, hydrophilicity, good water dispersibility, strong fluorescent stability, graphene oxide quantum dots (o-CQDs) are selected and embedded into PS microspheres, i.e., o-CQDs@PS, by microemulsion polymerization and denoted as CPS. Meanwhile, the sizes of CPS, e.g., 100, 150, and 200 nm, could be controlled by optimizing the type and number of water-soluble initiators. The anti-interference, low toxicity, and in vivo fluorescent tracing of CPS are proven by the coexistence of metals (including Fe2+, Fe3+, K+, Ba2+, Al3+, Zn2+, Mg2+, Ca2+, and Na+) on the fluorescence intensity of CPS, the growth of Chlorella pyrenoidosa and Artemia cysts as aquatic phytoplankton and zooplankton cultured with CPS, and the transfer of CPS from water into brine shrimp. In the concentration range of 0.1-100 mg/L, CPS can be quantitatively determined, which is suitable for coastal water and wastewater treatment plants. Therefore, CPS with standard size is suitable as reference material of PS.


Asunto(s)
Chlorella , Contaminantes Ambientales , Nanosferas , Puntos Cuánticos , Animales , Artemia/metabolismo , Contaminantes Ambientales/metabolismo , Grafito , Microplásticos , Poliestirenos/toxicidad , Puntos Cuánticos/toxicidad , Agua/metabolismo
20.
Nat Prod Bioprospect ; 11(6): 643-649, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34529253

RESUMEN

Ten 3,5-dimethylcoumarins (1-6 and 8‒11) involving six new ones (1-6), together with a known 3-methylcoumarin (7), were isolated from the aerial parts of three Chelonopsis plants, C. praecox, C. odontochila, and C. pseudobracteata. The structures of the new compounds were determined by extensive HRESIMS, 1D and 2D NMR spectroscopic analyses. According to the substitution at C-5, these coumarins were classified into 5-methyl, 5-hydroxymethyl, 5-formyl, and 5-nor types. All the isolates were assayed for their inhibition on α-glucosidase, protein tyrosine phosphatase 1B, and T-cell protein tyrosine phosphatase in vitro.

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