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1.
Angew Chem Int Ed Engl ; 63(23): e202402509, 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38588046

RESUMEN

Membranes are important in the pharmaceutical industry for the separation of antibiotics and salts. However, its widespread adoption has been hindered by limited control of the membrane microstructure (pore architecture and free-volume elements), separation threshold, scalability, and operational stability. In this study, 4,4',4'',4'''-methanetetrayltetrakis(benzene-1,2-diamine) (MTLB) as prepared as a molecular building block for fabricating thin-film composite membranes (TFCMs) via interfacial polymerization. The relatively large molecular size and rigid molecular structure of MTLB, along with its non-coplanar and distorted conformation, produced thin and defect-free selective layers (~27 nm) with ideal microporosities for antibiotic desalination. These structural advantages yielded an unprecedented high performance with a water permeance of 45.2 L m-2 h-1 bar-1 and efficient antibiotic desalination (NaCl/adriamycin selectivity of 422). We demonstrated the feasibility of the industrial scaling of the membrane into a spiral-wound module (with an effective area of 2.0 m2). This module exhibited long-term stability and performance that surpassed those of state-of-the-art membranes used for antibiotic desalination. This study provides a scientific reference for the development of high-performance TFCMs for water purification and desalination in the pharmaceutical industry.


Asunto(s)
Antibacterianos , Membranas Artificiales , Nylons , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Nylons/química , Purificación del Agua/métodos , Filtración/métodos , Permeabilidad
2.
Bull Environ Contam Toxicol ; 107(4): 754-763, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32556690

RESUMEN

Microplastic pollution in aquatic environment has raised concern and as a result a number of studies have recently been published to find solutions for its rapid increase. Different methods have been proposed for microplastic identification. Spectral imaging shows a lot of promise for polymer identification; however, the identification time needs to be improved. Hyperspectral imaging (HSI) combined with chemometric analysis can reduce the identification times. In this study, we provide a review of recent studies related to polymer identification using HSI with a focus on the adopted classification algorithm and its factors for the online implementation of HSI. Furthermore, we review the limit of detection by HSI and the effect of particle size on classification accuracy. Additionally, performance of this method for various types of samples is also discussed. We conclude that HSI is possible to be a fast alternative for online microplastic detection.


Asunto(s)
Microplásticos , Plásticos , Algoritmos , Imágenes Hiperespectrales , Polímeros
3.
Ecotoxicol Environ Saf ; 196: 110536, 2020 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-32234585

RESUMEN

Rivers are important routes for sea-bound microplastics. Thus, this study investigated the occurrences and distributions of microplastics and polychlorinated biphenyls (PCBs) in sediment samples from the Qiantang River (QR) and Hangzhou Bay (HZ) and analyzed the correlation between microplastics and PCBs. A total of 15 sampling sites were selected, including eight from the QR (i.e., four in the Tonglu area and four in the Fuyang area), two from the Andong salt marsh (ASM; located in a hydrodynamic turning point of the HZ), and five from HZ. The mean microplastic abundance was highest in the QR, followed by HZ and ASM, with 0.23 ± 0.06, 0.18 ± 0.05, and 0.15 ± 0.03 particles/g sediment, respectively. Cluster analysis demonstrated that fragments and fibers may have originated from domestic sewage inputs to the QR. Spatially, mean PCB concentrations from Tonglu, Fuyang, and HZ were 1.47 ± 0.10, 1.65 ± 0.10, and 1.65 ± 0.09 ng/g sediment, respectively, which were higher than that from the ASM (1.13 ± 0.09 ng/g sediment). The vertical distributions (0-5 cm, 5-10 cm, and 10-15 cm) of microplastics in the sediments at Tonglu and Fuyang decreased with increasing depth, which was opposite to the depth trend of PCB concentrations. Micro-Fourier transform infrared spectroscopy analysis suggested that polyethylene was typically the dominant polymer, accounting for 60 ± 0.08% of the total suspected plastic particles. Microbeads and films showed considerable correlations with both highly and lesser chlorinated PCBs. Overall, our findings highlight the need for routine monitoring of microplastics in China in addition to measures for controlling plastic pollution on a national scale. Further study should ascertain specific sources of microplastics and analyze their adsorption capacity to organic pollutants.


Asunto(s)
Monitoreo del Ambiente/métodos , Sedimentos Geológicos/química , Microplásticos/análisis , Bifenilos Policlorados/análisis , Contaminantes Químicos del Agua/análisis , Bahías , China , Ríos/química
4.
Molecules ; 20(9): 16788-816, 2015 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-26389873

RESUMEN

Over the past decade, a variety of ionic liquids have emerged as greener solvents for use in the chemical manufacturing industries. Their unique properties have attracted the interest of chemists worldwide to employ them as replacement for conventional solvents in a diverse range of chemical transformations including biotransformations. Biocatalysts are often regarded as green catalysts compared to conventional chemical catalysts in organic synthesis owing to their properties of low toxicity, biodegradability, excellent selectivity and good catalytic performance under mild reaction conditions. Similarly, a selected number of specific ionic liquids can be considered as greener solvents superior to organic solvents owing to their negligible vapor pressure, low flammability, low toxicity and ability to dissolve a wide range of organic and biological substances, including proteins. A combination of biocatalysts and ionic liquids thus appears to be a logical and promising opportunity for industrial use as an alternative to conventional organic chemistry processes employing organic solvents. This article provides an overview of recent developments in this field with special emphasis on the application of more sustainable enzyme-catalyzed reactions and separation processes employing ionic liquids, driven by advances in fundamental knowledge, process optimization and industrial deployment.


Asunto(s)
Biocatálisis , Materiales Biocompatibles/síntesis química , Líquidos Iónicos , Biotransformación , Humanos
5.
Protein Expr Purif ; 104: 34-40, 2014 12.
Artículo en Inglés | MEDLINE | ID: mdl-25251715

RESUMEN

In this study, a pyridine-based compound, 4'-terpyridinylsulfanylethylamine (4'-TerPSEA), has been employed as a ligand to purify via mixed-mode chromatographic procedures a humanised monoclonal antibody of the IgG1 sub-class directly from crude supernatants derived from cultured CHO cells. The antibody binding capacity, selectivity and reusability of the adsorbent, derived from the immobilisation of this ligand onto Sepharose FF™, were compared to a Protein A affinity resin. The chromatographic performance of this mixed mode adsorbent was similar to that shown by the Protein A-based adsorbent with this IgG1 mAb. In addition, the IgG1 mAb was able to bind to the immobilised 4'-TerPSEA under reducing conditions. Through the use of papain-digested IgG1 mAb, fractionated with both the 4'-TerPSEA and Protein A adsorbents, it was found that this IgG1 mAb preferentially bound to the immobilised 4'-TerPSEA Sepharose FF™ resin through its Fc region.


Asunto(s)
2,2'-Dipiridil/análogos & derivados , Anticuerpos Monoclonales Humanizados/aislamiento & purificación , Anticuerpos Monoclonales/aislamiento & purificación , Cisteamina/análogos & derivados , Inmunoglobulina G/aislamiento & purificación , Resinas Sintéticas/química , 2,2'-Dipiridil/química , Adsorción , Animales , Células CHO , Cromatografía Liquida/métodos , Cricetinae , Cricetulus , Cisteamina/química , Ligandos , Unión Proteica , Piridinas/química , Sefarosa/química , Proteína Estafilocócica A/química
6.
Environ Pollut ; 341: 123008, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38006990

RESUMEN

Cold seep sediments are an important reservoir of microplastics (MPs) whose impact on the structure and function of prokaryotic community is not well understood. In this study, the impact of 0.2% and 1% (w/w) polyethylene (PE), polystyrene (PS), and polypropylene (PP) MPs on the cold seep sediment prokaryotic community was investigated in a 120-day laboratory incubation experiment. The results revealed that exposure to MPs altered sedimentary chemical properties in a type- and concentration-dependent manner. Furthermore, MPs significantly altered the structure of bacterial community, with some MPs degradation-associated bacterial phyla significantly increasing (p < 0.05). However, in the case of archaea, the changes in the structure of microbial community were less pronounced (p > 0.05). Co-occurrence network analysis revealed that the addition of MPs reduced the network complexity, while PICRUSt2 and FAPROTAX analyses suggested that 0.2% PP and 1% PS MPs had the most significant effects on the nitrogen and carbon cycles (p < 0.05). Overall, this study provides new insights into the effects of MPs on the structure and function of microbial communities in cold seep sediments.


Asunto(s)
Microplásticos , Plásticos , Bacterias , Archaea , Polipropilenos , Poliestirenos
7.
Environ Pollut ; 316(Pt 2): 120707, 2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-36427829

RESUMEN

Microplastics (MPs) can absorb halogenated organic compounds and transport them into marine anaerobic zones. Microbial reductive dehalogenation is a major process that naturally attenuates organohalide pollutants in anaerobic environments. Here, we aimed to determine the mechanisms through which MPs affect the microbe-mediated marine halogen cycle by incubating 2,4,6-trichlorophenol (TCP) dechlorinating cultures with various types of MPs. We found that TCP was dechlorinated to 4-chlorophenol in biotic control and polypropylene (PP) cultures, but essentially terminated at 2,4-dichlorophenol in polyethylene (PE) and polyethylene terephthalate (PET) cultures after incubation for 20 days. Oxygen-containing functional groups such as peroxide and aldehyde were enriched on PE and PET after incubation and corresponded to elevated levels of intracellular reactive oxygen species (ROS) in the microorganisms. Adding PE or PET to the cultures exerted limited effects on hydrogenase and ATPase activities, but delayed the expression of the gene encoding reductive dehalogenase (RDase). Considering the limited changes in the microbial composition of the enriched cultures, these findings suggested that microbial dechlorination is probably affected by MPs through the ROS-induced inhibition of RDase synthesis and/or activity. Overall, our findings showed that extensive MP pollution is unfavorable to environmental xenobiotic detoxification.


Asunto(s)
Clorofenoles , Microplásticos , Plásticos , Anaerobiosis , Especies Reactivas de Oxígeno , Clorofenoles/toxicidad , Polietileno , Tereftalatos Polietilenos
8.
Sci Total Environ ; 881: 163366, 2023 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-37044349

RESUMEN

To date, multiple studies have shown that the accumulation of microplastics (MPs)/nanoplastics (NPs) in the environment may lead to various problems. However, the effects of MPs/NPs on microbial communities and biogeochemical processes, particularly methane metabolism in cold seep sediments, have not been well elucidated. In this study, an indoor microcosm experiment for a period of 120 days exposure of MPs/NPs was conducted. The results showed that MPs/NPs addition did not significantly influence bacterial and archaeal richness in comparison with the control (p > 0.05), whereas higher levels of NPs (1 %, w/w) had a significant adverse effect on bacterial diversity (p < 0.05). Moreover, the bacterial community was more sensitive to the addition of MPs/NPs than the archaea, and Epsilonbacteraeota replaced Proteobacteria as the dominant phylum in the MPs/NPs treatments (except 0.2 % NPs). With respect to the co-occurrence relationships, network analysis showed that the presence of NPs, in comparison with MPs, reduced microbial network complexity. Finally, the presence of MPs/NPs decreased the abundance of mcrA, while promoting the abundance of pmoA. This study will help elucidate the responses of microbial communities to MPs/NPs and evaluate their effects on methane metabolism in cold seep ecosystems.


Asunto(s)
Microbiota , Plásticos , Plásticos/metabolismo , Polietileno/metabolismo , Bacterias/metabolismo , Archaea/metabolismo , Microplásticos/metabolismo , Metano/metabolismo
9.
J Hazard Mater ; 452: 131350, 2023 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-37030223

RESUMEN

Polychlorinated biphenyls (PCBs) and microplastics (MPs) commonly co-exist in various environments. MPs inevitably start aging once they enter environment. In this study, the effect of photo-aged polystyrene MPs on microbial PCB dechlorination was investigated. After a UV aging treatment, the proportion of oxygen-containing groups in MPs increased. Photo-aging promoted the inhibitory effect of MPs on microbial reductive dechlorination of PCBs, mainly attributed to the inhibition of meta-chlorine removal. The inhibitory effects on hydrogenase and adenosine triphosphatase activity by MPs increased with increasing aging degree, which may be attributed to electron transfer chain inhibition. PERMANOVA showed significant differences in microbial community structure between culturing systems with and without MPs (p < 0.05). Co-occurrence network showed a simpler structure and higher proportion of negative correlation in the presence of MPs, especially for biofilms, resulting in increased potential for competition among bacteria. MP addition altered microbial community diversity, structure, interactions, and assembly processes, which was more deterministic in biofilms than in suspension cultures, especially regarding the bins of Dehalococcoides. This study sheds light on the microbial reductive dechlorination metabolisms and mechanisms where PCBs and MPs co-exist and provides theoretical guidance for in situ application of PCB bioremediation technology.


Asunto(s)
Bifenilos Policlorados , Envejecimiento de la Piel , Bifenilos Policlorados/metabolismo , Microplásticos , Plásticos , Poliestirenos , Biodegradación Ambiental , Cloro/farmacología , Cloro/metabolismo , Sedimentos Geológicos/microbiología
10.
Sci Adv ; 9(18): eadg6134, 2023 05 05.
Artículo en Inglés | MEDLINE | ID: mdl-37146143

RESUMEN

The successful implementation of thin-film composite membranes (TFCM) for challenging solute-solute separations in the pharmaceutical industry requires a fine control over the microstructure (size, distribution, and connectivity of the free-volume elements) and thickness of the selective layer. For example, desalinating antibiotic streams requires highly interconnected free-volume elements of the right size to block antibiotics but allow the passage of salt ions and water. Here, we introduce stevioside, a plant-derived contorted glycoside, as a promising aqueous phase monomer for optimizing the microstructure of TFCM made via interfacial polymerization. The low diffusion rate and moderate reactivity of stevioside, together with its nonplanar and distorted conformation, produced thin selective layers with an ideal microporosity for antibiotic desalination. For example, an optimized 18-nm membrane exhibited an unprecedented combination of high water permeance (81.2 liter m-2 hour-1 bar-1), antibiotic desalination efficiency (NaCl/tetracycline separation factor of 11.4), antifouling performance, and chlorine resistance.


Asunto(s)
Antibacterianos , Tetraciclina , Cloruros , Extractos Vegetales , Poliésteres
11.
Sci Total Environ ; 831: 154904, 2022 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-35364163

RESUMEN

Microplastics (MPs) and polychlorinated biphenyls (PCBs) generally coexist in the environment, posing risks to public health and the environment. This study investigated the effect of different MPs on the microbial anaerobic reductive dechlorination of Aroclor 1260, a commercial PCB mixture. MP exposure inhibited microbial reductive dechlorination of PCBs, with inhibition rates of 39.43%, 23.97%, and 17.53% by polyethylene (PE), polypropylene (PP), and polystyrene (PS), respectively. The dechlorination rate decreased from 1.63 µM Cl- d-1 to 0.99-1.34 µM Cl- d-1 after MP amendment. Chlorine removal in the meta-position of PCBs was primarily inhibited by MPs, with no changes in the final PCB dechlorination metabolites. The microbial community compositions in MP biofilms were not significantly different (P > 0.05) from those in suspension culture, although possessing greater Dehalococcoides abundance (0.52-0.81% in MP biofilms; 0.03-0.12% in suspension culture). The co-occurrence network analysis revealed that the presence of MPs attenuated microbial synergistic interactions in the dechlorinating culture systems, which may contribute to the inhibitory effect on microbial PCB dechlorination. These findings are important for comprehensively understanding microbial dechlorination behavior and the environmental fate of PCBs in environments with co-existing PCBs and MPs and for guiding the application of in situ PCB bioremediation.


Asunto(s)
Chloroflexi , Bifenilos Policlorados , Arocloros , Biodegradación Ambiental , Cloro/metabolismo , Chloroflexi/metabolismo , Sedimentos Geológicos , Microplásticos , Plásticos/metabolismo , Bifenilos Policlorados/metabolismo
12.
Mar Pollut Bull ; 181: 113912, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35870383

RESUMEN

Sediments are considered to be important sinks of microplastics, but the enrichment process of microplastics by blue carbon ecosystems is poorly studied. This study analyzed the spatial distribution and temporal changes, assessed the polymer types and morphological characteristics of microplastics in sediments of five ecosystems, i.e. forests, paddy fields, mangroves, saltmarshes and bare beaches on Ximen Island, Yueqing Bay, China. The trapping effect of blue carbon (mangrove and saltmarsh) sediments on microplastic was further explored. Temporal trends in microplastic abundance showed a significant increase over the last 20 years, with the enrichment of microplastics in mangrove and saltmarsh sediments being 1.7 times as high as that in bare beach, exhibiting blue carbon vegetations have strong enrichment effect on microplastics. The dominant color, shape, size, and polymer type of microplastics in sediments were transparent, fibers and fragments, <1 mm, and polyethylene, respectively. Significant differences in the abundance and characteristics of microplastics between intertidal sediments and terrestrial soils reveal that runoff input is the main source of microplastics. This study provided the evidence of blue carbon habitats as traps of microplastics.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Carbono , Ecosistema , Monitoreo del Ambiente , Sedimentos Geológicos , Plásticos , Contaminantes Químicos del Agua/análisis
13.
Environ Pollut ; 272: 115939, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33189442

RESUMEN

This study investigates the occurrence and distribution of microplastics in water, sediment, and crayfish samples within pond and rice-crayfish co-culture breeding modes in Jianli prefecture, China. Microplastics in environmental and biological samples were systematically extracted by CaCl2 solution, digested by H2O2 and KOH, and identified by µ-FTIR. A cleansing treatment for crayfish was performed in pure water before dissection and microplastic accumulation in different tissues (gill, stomach, gut, and flesh) of non-cleansed and cleansed crayfish were compared. The average microplastic abundances were 1.3 ± 0.1-2.5 ± 0.1 particles/L, 0.03 ± 0.01-0.04 ± 0.02 particles/g, and 0.17 ± 0.07-0.92 ± 0.19 particles/individual in water, sediment, and crayfish samples, respectively. Microplastics were detected in all studied crayfish tissues, except the flesh. There were no significant differences in microplastic abundances in water (P = 0.82), sediment (P = 0.90), and crayfish (P = 0.47 for non-cleansed samples; P = 0.30 for cleansed samples) between two breeding modes despite the detection of relatively higher microplastic abundances in the samples from the pond breeding mode. Microplastic accumulation in non-cleansed crayfish stomachs and guts (0.71 ± 0.18 particles/individual) was higher (P < 0.01) than that recorded in their gills (0.13 ± 0.06 particles/individual). Moreover, microplastics present in the stomachs and guts of cleansed crayfish were significantly less abundant (P < 0.01) than in non-cleansed crayfish, although this was not observed in the gills (P = 0.99). The majority of microplastic particles in this study had fiber-like shapes, blue and transparent colors, a size smaller than 1 mm, and polymer types of PP:PE and PE. The results demonstrate that microplastics in the environment can accumulate in the internal tissues of crayfish, which may pose a potential risk to humans through food consumption without the removal of the gills, stomach, and guts. This study provides valuable information for understanding microplastic accumulation in the different tissues of crayfish and the potential risk of human exposure to microplastics from crayfish as a food supplement.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Animales , Astacoidea , China , Monitoreo del Ambiente , Humanos , Peróxido de Hidrógeno , Fitomejoramiento , Plásticos , Agua , Contaminantes Químicos del Agua/análisis
14.
Sci Total Environ ; 733: 139400, 2020 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-32446095

RESUMEN

This study investigates the influence of marine habitats (i.e., the intertidal zone, supralittoral zone, and seawater), and polymer types (i.e., polyethylene, PE; polyethylene terephthalate, PET) on the diversity and structure of bacterial communities in marine microplastics. A three-month exposure experiment was conducted in Zhairuoshan Island, Zhoushan, China, a typical caldera volcanic island with minor anthropogenic disturbances. At the end of the exposure period, the transition for peaks corresponding to oxidized groups was observed using micro-Fourier transform infrared spectroscopy. Damages, including pits and cracks, and microorganisms were observed on the surfaces of the PE and PET pellets using scanning electron microscopy. Next-generation amplicon sequencing of the bacterial communities that had colonized the microplastics revealed that bacterial composition significantly varied depending on marine habitats and exposure times, rather than polymer type. Plastic debris in the intertidal zone exhibited the highest bacterial richness and diversity, and Bacillus was considered a potential degrader of plastic debris. The findings demonstrate that bacterial communities that colonize on microplastics are more potentially shaped by marine habitat and exposure time, and this would deepen our understanding of the ecological niche of microplastics surface.


Asunto(s)
Plásticos , Contaminantes Químicos del Agua/análisis , China , Ecosistema , Monitoreo del Ambiente , Microplásticos
15.
Environ Pollut ; 259: 113948, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32023798

RESUMEN

Microplastics are ubiquitous in marine environments. Sediments and marine organisms are recognized as the carriers and final destinations of microplastics. However, research on the concentration and abundance of microplastics in deep-sea sediments and organisms is limited. In this study, samples of sediments and organisms were collected from deep-sea locations of the western Pacific Ocean, with the depth ranging from 4601 m to 5732 m. Microplastics were extracted from the samples and analyzed by micro-Fourier-transform infrared spectroscopy. The average abundance of microplastics in the sediments was 240 items per kg dry weight of sediment. The microplastics were predominantly fibrous in shape (52.5%), blue in color (45.0%), and less than 1 mm in size (90.0%). The most commonly detected polymers were poly(propylene-ethylene) copolymer (40.0%) and polyethylene terephthalate (27.5%). The concentrations of polychlorinated biphenyls (PCBs), which are representatives of persistent organic pollutants, in the pore water of sediment samples were also investigated. A significant correlation between the distribution of microplastics and the PCB concentrations in sediments was found (P = 0.016). Microplastics were also detected in deep-sea organisms (i.e., Crinoidea, Pheronematidae, Ophiuroidea, and Gammaridea) in the sampling region, with an abundance of 0-3 items per individual biological sample. This assessment of microplastics in deep-sea sediments and benthic organisms of the western Pacific Ocean confirms that microplastic pollution exists in the deep-sea ecosystems of this region.


Asunto(s)
Monitoreo del Ambiente , Microplásticos/análisis , Contaminantes Químicos del Agua/análisis , Ecosistema , Sedimentos Geológicos/química , Océano Pacífico , Plásticos
16.
Mar Environ Res ; 162: 105151, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32956972

RESUMEN

This study investigated the physicochemical surface changes of various plastics caused by indigenous communities. The first invading microbes on plastics in 4 different aquatic communities including seawater, freshwater, marine sediments and lake sediments were developed in microcosm incubation experiments. A mixture of weathered plastics (PE, PS, PET) was incubated with different indigenous communities under their respective habitat simulations. All microbial communities were able to form populations on all plastic surfaces with time-dependent development. Biofilm also affected floatation of plastics and the communities on PE foam (PF) were dominated by genera affiliated with plastic and hydrocarbon degraders. The results showed that indigenous populations were able to degrade plastic pieces and utilize them as carbon sources where the weight of PF was reduced more effectively than PS and PET. Besides, carbonyl groups that were seen with FTIR on initial PF disappeared after microbial treatment along with signs of bioerosion on the plastic surface.


Asunto(s)
Microbiota , Plásticos , Bacterias , Biopelículas , Agua de Mar
17.
Sci Total Environ ; 703: 134768, 2020 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-31726304

RESUMEN

In this study, the occurrence and distribution of microplastics in artificial reefs around the Ma'an Archipelago, a national marine ranching area in China, were investigated. The abundance of microplastics ranged from 0.2 ±â€¯0.1 to 0.6 ±â€¯0.2 items L-1 in surface water, 30.0 ±â€¯0.0 to 80.0 ±â€¯14.1 items kg-1 dry weight in the sediment, and 2.3 ±â€¯1.5 to 7.3 ±â€¯3.5 items individual-1 in fish. Most of the detected microplastics were fiber-shaped, blue or transparent, and smaller than 1 mm. Polyethylene, polypropylene, and poly(ethylene:propylene:diene) copolymer were the most abundant polymer types in the surface water samples, whereas cellophane was dominant in the sediment and fish. The appearance of microplastic pollution around the artificial reefs could be attributed mainly to the activities of the fisheries in the area, whereas the microplastic ingestion by fish was affected by the extent of microplastic contamination of the sediment. The results highlight the widespread presence of microplastics in the water, sediment, and biota of the artificial reefs around the Ma'an Archipelago, thereby improving understanding of the environmental risks posed by microplastics to marine artificial reef ecosystems and fisheries in general.


Asunto(s)
Microplásticos , Animales , China , Ecosistema , Monitoreo del Ambiente , Contaminantes Ambientales , Peces , Sedimentos Geológicos , Agua
18.
Environ Pollut ; 244: 827-833, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30390456

RESUMEN

Microplastic particles are a global concern due to their widespread and growing threat to marine and coastal environments. To improve knowledge of microplastic pollution in China, we investigated 25 sediment samples collected with a box corer in the Southern Yellow Sea and East China Sea off the coast of China. The microplastics were extracted from sediments via density separation, after which they were observed under a microscope and characterized according to shape, color, and size, while polymer type identification was performed using micro-Fourier transform infrared spectroscopy. The abundance of microplastics in the offshore region of the Southern Yellow Sea and East China Sea was mapped. The mean concentration of microplastics at the 25 sites was 13.4 ±â€¯0.6 particles 100 g-1 dry weight (range: 6.0-24.0 particles 100 g-1 dry weight). Based on the categorization according to shape, color, and size, fiber (77%) was the most abundant shape, while blue (35%) and transparent (29%) were the most prevalent colors. In addition, the dominant size of microplastics was smaller than 1000 µm which accounted for 89%. Finally, polyethylene, polyethylene terephthalate, acrylic, polyester, cellulose, and cellophane were the most abundant types of microplastics identified. Our result highlighted the presence of microplastics in offshore sediments from the Yellow Sea and East China Sea, and provided useful information for evaluating the environmental risks posed by microplastics in China.


Asunto(s)
Monitoreo del Ambiente/métodos , Sedimentos Geológicos/química , Polietileno/análisis , Contaminantes del Suelo/química , Contaminantes Químicos del Agua/análisis , Contaminación Química del Agua/análisis , China , Ambiente , Océanos y Mares , Espectroscopía Infrarroja por Transformada de Fourier
19.
J Microbiol Biotechnol ; 28(2): 305-313, 2018 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-29429304

RESUMEN

A microbial consortium, TMC7, was enriched for the degradation of natural lignocellulosic materials under high temperature. TMC7 degraded 79.7% of rice straw during 15 days of incubation at 65°C. Extracellular xylanase was effectively secreted and hemicellulose was mainly degraded in the early stage (first 3 days), whereas primary decomposition of cellulose was observed as of day 3. The optimal temperature and initial pH for extracellular xylanase activity and lignocellulose degradation were 65°C and between 7.0 and 9.0, respectively. Extracellular xylanase activity was maintained above 80% and 85% over a wide range of temperature (50-75°C) and pH values (6.0-11.0), respectively. Clostridium likely had the largest contribution to lignocellulose conversion in TMC7 initially, and Geobacillus, Aeribacillus, and Thermoanaerobacterium might have also been involved in the later phase. These results demonstrate the potential practical application of TMC7 for lignocellulosic biomass utilization in the biotechnological industry under hot and alkaline conditions.


Asunto(s)
Bacterias/enzimología , Lignina/metabolismo , Consorcios Microbianos/fisiología , Xilosidasas/metabolismo , Bacterias/clasificación , Bacterias/genética , Bacterias/metabolismo , Basidiomycota , Biodegradación Ambiental , Biomasa , Biotecnología , Celulosa/metabolismo , Activación Enzimática , Pruebas de Enzimas , Estabilidad de Enzimas , Fermentación , Concentración de Iones de Hidrógeno , Microbiología Industrial , Consorcios Microbianos/genética , Oryza , Polisacáridos/metabolismo , ARN Ribosómico 16S/genética , Temperatura , Factores de Tiempo
20.
Adv Healthc Mater ; 7(22): e1800830, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30240165

RESUMEN

Although various types of photothermal agents are developed for photothermal cancer therapy, relatively few photothermal agents exhibit high tumor inhibition rate under relatively mild conditions. Herein, a multifunctional Bi2 S3 -Tween 20 nanoplatform loaded with PI3K inhibitor LY294002 is designed as a novel photothermal agent for inhibitor and photothermal synergistic therapy of tumors under mild photothermal therapy conditions. The LY294002 of PI3K inhibitor, after being loaded by Bi2 S3 -Tween 20 nanodots, exhibits greatly increased drug utilization and reduced side effects on normal tissues. In vivo, Bi2 S3 -Tween 20@LY294002 upon near-infrared 808 nm laser irradiation shows potent antitumor activity under relatively mild conditions (power density: 0.6 W cm-2 ). Moreover, the mechanism studies also demonstrate that Bi2 S3 -Tween 20@LY294002 potently kills LoVo cancer cells under low-power near-infrared light irradiation, by downregulating the expression of heat shock protein 70 (HSP70) so as to increase the sensitivity of tumor cell hyperthermia and activating BAX/BAK-regulated mitochondrial apoptosis pathway. The results demonstrate that the newly synthesized multifunctional nanoplatform paves a new avenue for accurate therapy of photothermal-resistant cancer.


Asunto(s)
Bismuto/química , Cromonas/química , Morfolinas/química , Nanopartículas/química , Polisorbatos/química , Sulfuros/química , Animales , Apoptosis/efectos de los fármacos , Apoptosis/efectos de la radiación , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Cromonas/farmacología , Cromonas/uso terapéutico , Regulación hacia Abajo/efectos de los fármacos , Proteínas HSP70 de Choque Térmico/metabolismo , Hemólisis/efectos de los fármacos , Humanos , Hipertermia Inducida , Rayos Infrarrojos , Ratones , Ratones Desnudos , Morfolinas/farmacología , Morfolinas/uso terapéutico , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Neoplasias/terapia , Inhibidores de las Quinasa Fosfoinosítidos-3 , Fototerapia , Proteína X Asociada a bcl-2/metabolismo
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