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1.
Environ Pollut ; 319: 120994, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36603757

RESUMO

Microplastics (MPs) are present across the global ocean and can be encountered by many species, including zooplankton. Although they fall within the size range of zooplankton prey, there are few studies on MPs ingestion carried out in situ. In this study, we analyzed MPs ingestion during two seasons (rainy and dry) of organisms from 5 taxonomic groups of zooplankton from two bays of the Mexican central Pacific: Manzanillo and Navidad. In total, 2643 individuals were analyzed, and of those 23 individuals contained MPs. The ingestion rate by taxonomic group was 1 MP/36 copepods (0.02), 1 MP/30 decapods-mysis (0.03), 1 MP/29 decapods-megalopa (0.03), and 1 MP/200 fish larvae (0.005). No plastics were found in chaetognaths, amphipods, or decapods-zoea. The average length of the ingested particles was 468.1 ± 113.8 µm, with a minimum of 15.6 and a maximum of 647.6 µm. All MPs >300 µm were fibers, with diameters <50 µm. Fragments were the most abundant MPs (54.2%), followed by fibers (34.2%) and spheres (11.4%). Statistical analyses showed no significant differences (p > 0.05) between the bays or seasons. Using RAMAN spectroscopy, it was possible to identify 6 different types of polymers, with poly (ethylene:propylene) being the most abundant (42.8%). This polymer is commonly used to manufacture plastic bags, ropes and fishing nets. The results confirm that certain zooplankton groups are consuming MPs and suggest that omnivorous species are more likely to ingest MPs, possibly due to their capacity for foraging flexibility and opportunistic feeding strategies. However, the ingestion of MPs cannot be attributed to a single factor; it is necessary to consider variables such as the sampling area, feeding strategy, size, and seasonality to understand the dynamics of MPs ingestion by zooplankton groups.


Assuntos
Poluentes Químicos da Água , Zooplâncton , Animais , Microplásticos , Plásticos , Poluentes Químicos da Água/análise , Monitoramento Ambiental/métodos , Polietileno , Ingestão de Alimentos
2.
Chemosphere ; 315: 137745, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36608883

RESUMO

Microplastics are plastic particles less than 5 mm in diameter and are widely present in water environments. Their unique surface structures can adsorb coexisting pollutants in the surrounding environment, such as antibiotics and metal ions, leading to compound pollution. The adsorption of ciprofloxacin on polyethylene microplastics under different environmental conditions (pH and salinity) was investigated. The Freundlich model fitted well at 25 °C, indicating that the adsorption of ciprofloxacin by polyethylene microplastics was multilayered, and Fourier Transform infrared spectroscopy (FTIR) analysis indicated that the adsorption of ciprofloxacin by polyethylene microplastics was physical. The kinetic adsorption of ciprofloxacin on polyethylene microplastics followed a pseudo-second-order mode. Heavy metals (Cu2+, Cr3+, Cr6+, Cd2+, and Pb2+) affected the adsorption of ciprofloxacin by microplastics, which was related to the type and concentration of metal ions and the valence state of the ions. The acute toxicity of microplastics and the microplastic-ciprofloxacin-Cu2+ complex were evaluated using luminescent Photobacterium phosphoreum, demonstrating the polyethylene toxicity microplastic-ciprofloxacin-Cu2+ complex was mainly caused by Cu2+ and ciprofloxacin rather than microplastics. This study provides theoretical support for the environmental behavior and ecological effects of microplastics in aqueous environments.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Microplásticos/química , Plásticos/química , Polietileno/toxicidade , Ciprofloxacina/toxicidade , Ciprofloxacina/análise , Adsorção , Poluentes Químicos da Água/análise , Metais Pesados/toxicidade , Metais Pesados/química , Íons
3.
J Hazard Mater ; 446: 130652, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36603420

RESUMO

Per- and polyfluoroalkyl substances (PFASs) present adverse effects for human health, which result in strong needs for reliable tools monitoring personal exposure to PFASs. This study manufactured two wristbands of high density polyethylene (HDPE) and thermoplastic polyurethane (TPU), and used the wristbands to monitor PFASs personal exposure. The analytical method was developed to measure 32 PFASs in the paired HDPE and TPU wristbands worn by 60 postgraduates. Twenty-nine of 32 PFASs were detected and hexafluoropropylene oxide dimer acid (HFPO-DA) was predominant individual PFASs with median concentrations of 337 and 554 pg/g for HDPE and TPU wristbands respectively. The gender and grade of students had moderate effects on PFASs distribution in the wristbands. Higher PFASs levels were determined in the two wristbands worn by the male students compared to the females, and the greatest PFASs concentration was observed in the wristbands worn by the first-year postgraduates, follow by second- and third-year postgraduates. Additionally, significant correlations between paired HDPE and TPU wristbands were observed for perfluorobutanoic acid (PFBA), perfluorohexane sulfonic acid (PFHxS), perfluoroheptane sulfonic acid (PFHpS), perfluorooctane sulfonic acid (PFOS), and HFPO-DA. These results suggest that HDPE and TPU wristbands can be used as effective tools for monitoring personal PFAS exposure.


Assuntos
Ácidos Alcanossulfônicos , Fluorcarbonetos , Feminino , Humanos , Masculino , Polietileno , Poliuretanos , Fluorcarbonetos/análise , Estudantes , Monitoramento Ambiental
4.
J Hazard Mater ; 446: 130717, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36610343

RESUMO

Large amounts of microplastics (MPs) accumulate in the sludge anaerobic digestion system after being treated by the wastewater treatment plants, inevitably leading to aging and chemicals leaching. However, no information is available about the effects of aged MPs and leachates on the anaerobic digestion of sludge. In this study, the effects of different aged MPs ((polyethylene (PE), polyethylene terephthalate (PET), polyvinyl chloride (PVC), and polylactic acid (PLA)) and leachates on anaerobic methanogenesis of sludge were investigated. PLA-related treatments caused no adverse effects on anaerobic digestion. While PE-, PET-, and PVC-related treatments significantly inhibited methane production with an order of leachates (26.4-42.4 %) > MPs (16.1-22.9 %) > aged MPs (2.4-11.8 %). For different leachates, PET leachate caused the strongest inhibitory effects. The same order was found for the methane potential and hydrolysis coefficient. These results suggest that the inhibition of MPs on methanogenesis is mainly caused by the leachates. Based on biochemical and microbial community analysis, the primary mechanism is that the leachates induce oxidative stress, damaging microbial cells and reducing microbial activity, consequently inhibiting methanogenesis. Furthermore, via effect-directed analysis, methyl benzoate (MB), dimethyl phthalate (DMP), and 2,4-Di-tert-butylphenol (DTBP) were identified as key components in the PET-leachate inhibiting anaerobic methanogenesis.


Assuntos
Microplásticos , Esgotos , Microplásticos/toxicidade , Anaerobiose , Plásticos , Eliminação de Resíduos Líquidos/métodos , Polietilenotereftalatos , Polietileno , Metano , Reatores Biológicos
5.
J Hazard Mater ; 446: 130712, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36621296

RESUMO

With the intensification of microplastic (MP) pollution, the impact of MPs on soil ecosystems has garnered considerable attention. We investigated the effects of two commonly used MPs, polyethylene (PE) and polypropylene (PP), at different sizes and doses, on the properties and microbial communities in saline-alkali soil. We found that MP treatment significantly reduced the electrical conductivity but somewhat enhanced the enzyme activities and effective nutrient content of the soil. Microbial diversity is affected by the type, dose, size and interaction of MPs, with fungi being more sensitive than bacteria. Under high-dose PE treatment, the dominant bacteria and fungi enriched, and the diversity indexes declined significantly. Meanwhile, under high-dose PP treatment, several unique bacteria and fungi with low abundance were observed, which eventually increased the diversity indexes. Moreover, PE exerted a stronger effect on bacterial function than PP. High-dose PE treatment suppressed the nitrogen fixation potential of soil bacteria. However, high-dose PP treatment promoted that. In conclusion, our findings showed that PE exerts a stronger negative effect on saline-alkali soil ecosystems than PP. Our findings help bridge the knowledge gap in the impact of MPs on saline-alkaline soils and provide guidance for the rational use of agricultural plastics in saline-alkaline soils.


Assuntos
Microbiota , Poluentes do Solo , Microplásticos/farmacologia , Plásticos , Solo , Álcalis , Microbiologia do Solo , Poluentes do Solo/análise , Polipropilenos , Polietileno/farmacologia , Bactérias
6.
Anal Chim Acta ; 1239: 340746, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36628737

RESUMO

A diffuser-incorporated near-infrared (NIR) trans-reflectance measurement is demonstrated for quantitative detection of polyethylene (PE) particles captured in perfluorohexane (PFH, C6F14). PFH effectively captures PE particles through its hydrophobicity and absorbs little NIR radiation, recommending it for use in background-free NIR detection of captured PE particles. A reflective metal disk was used to push the captured PE particles in PFH toward the bottom of the vial that contained the sample, and the trans-reflectance measurement was performed by illuminating NIR radiation from the bottom of the vial at 45o. Reproducibility is limited by the variation in the positions of small PE-particle aggregates at the water/PFH interface and the difficulty in ensuring full NIR sampling (coverage) of large aggregates. An effective way to secure improved reproducibility under these circumstances is illumination of broader and more uniform NIR radiation for measurement. For this purpose, a polytetrafluoroethylene (PTFE) disk was uniquely incorporated as a diffuser for the trans-reflectance measurement. Compared to the measurement with no diffuser, the diffuser-incorporated scheme produced more distinct PE peaks of low-quantity samples (0.1 and 0.2 mg) and enhanced the reproducibility in measurements of all the samples (0.1-4.0 mg of PE). As a result, the correlation between peak intensity and particle quantity was excellent (R2: 0.997), and a limit of detection of 0.07 mg was achieved.


Assuntos
Fluorcarbonetos , Espectroscopia de Luz Próxima ao Infravermelho , Microplásticos , Plásticos , Estudos de Viabilidade , Reprodutibilidade dos Testes , Polietileno
7.
Artigo em Inglês | MEDLINE | ID: mdl-36674403

RESUMO

Fomite transmission is a possible route by which different pathogens spread within facilities. In hospital settings, elevator buttons are widely observed to be covered with various types of plastic wraps; however, limited information is available concerning the impact of different plastic materials on cleaning. Our study aimed to identify which plastic material is suitable for the coverage of elevator buttons and the optimal intervals for their cleaning. We tested six plastic covers, including polyethylene (PE), polymethylpentene (PMP), polyvinyl chloride (PVD), and polyvinylidene chloride (PVDC) plastic wraps; a thermoplastic polyurethane (TPU) keyboard cover; and a polyethylene terephthalate-ethylene vinyl acetate (PET-EVA) laminating film, which are plastic films. The bioburden on the elevator buttons at different time intervals was measured using an adenosine triphosphate (ATP) bioluminescence assay. Our results show that wraps made of PVDC had superior durability compared with those of PMP, PVC, and PVDC, in addition to the lowest detectable ATP levels among the six tested materials. Regarding different button locations, the highest ATP values were found in door-close buttons followed by door-open, and first-floor buttons after one- and three-hour intervals (p = 0.024 and p < 0.001, respectively). After routine disinfection, the ATP levels of buttons rapidly increased after touching and became more prominent after three hours (p < 0.05). Our results indicate that PVDC plastic wraps have adequate durability and the lowest residual bioburden when applied as covers for elevator buttons. Door-close and -open buttons were the most frequently touched sites, requiring more accurate and precise disinfection; therefore, cleaning intervals of no longer than three hours may be warranted.


Assuntos
Desinfecção , Elevadores e Escadas Rolantes , Polietileno , Trifosfato de Adenosina
8.
Bone Joint J ; 105-B(1): 29-34, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36587249

RESUMO

AIMS: Several short- and mid-term studies have shown minimal liner wear of highly cross-linked polyethylene (HXLPE) in total hip arthroplasty (THA), but the safety of using thinner HXLPE liners to maximize femoral head size remains uncertain. The objective of this study was to analyze clinical survival and radiological wear rates of patients with HXLPE liners, a 36 mm femoral head, and a small acetabular component with a minimum of ten years' follow-up. METHODS: We retrospectively identified 55 patients who underwent primary THA performed at a single centre, using HXLPE liners with 36 mm cobalt-chrome heads in acetabular components with an outer diameter of 52 mm or smaller. Patient demographic details, implant details, death, and all-cause revisions were recorded. Cox regression and Kaplan-Meier survival was used to determine all-cause and liner-specific revision. Of these 55 patients, 22 had a minimum radiological follow-up of seven years and were assessed radiologically for linear and volumetric wear. RESULTS: Overall survival rate for all-cause revision was 94.5% (95% confidence interval (CI) 81.7% to 97.2%) at a mean follow-up of 12.8 years (10.9 to 18.7). Three patients were revised, none for liner wear, fracture, or dissociation. A total of 22 patients were included in the radiological analysis (mean follow-up 9.9 years (7.5 to 13.7)). Mean linear liner wear was 0.085 mm (95% CI -0.086 to 0.257) and the volumetric wear rate was 11.097 mm3/year (95% CI -6.5 to 28.7). CONCLUSION: Using HXLPE liners with 36 mm heads in 52 mm acetabular components or smaller is safe, with excellent survival and low rates of linear and volumetric wear at medium-term follow-up. Patients did not require revision surgery for liner complications such as fracture, dissociation, or wear. Our results suggest that the advantages of using larger heads outweigh the potential risks of using thin HXLPE liners.Cite this article: Bone Joint J 2023;105-B(1):29-34.


Assuntos
Artroplastia de Quadril , Prótese de Quadril , Humanos , Artroplastia de Quadril/métodos , Polietileno , Seguimentos , Estudos Retrospectivos , Cabeça do Fêmur/cirurgia , Falha de Prótese , Desenho de Prótese
9.
Food Res Int ; 163: 112217, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36596146

RESUMO

In this study, the effect of ultrasound processing on the properties of two packages widely used in food products was evaluated: polyamide (PA) and polyethylene (PE) multilayer packaging. Packages composed of PE/PA/PE (Film A) and PE/PA/PE/PA/PE (Film B) were filled with aqueous and fatty food simulants and treated in an ultrasound water bath (frequency 25 kHz, volumetric power of 9.74 W/L, temperature of 25 °C, and time of 30 and 60 min). Materials were evaluated in term of structure and performance properties. Ultrasound did not or induced small changes in chemical groups, crystallinity, melting temperature, and tensile strength of the films. Film A showed a reduction in heat sealing tensile strength of 25% in the machine direction and 22% in the transverse direction. Film B showed a 20% increase of water vapor transmission rate after ultrasound processing. Although ultrasound had little impact on the properties of the evaluated materials, these modifications do not compromise the use of these packages for applications in ultrasound-processed foods. Therefore, the results indicate that ultrasound can be used as a food processing technology in multilayer PA and PE packaging.


Assuntos
Embalagem de Alimentos , Nylons , Embalagem de Alimentos/métodos , Polietileno/química , Manipulação de Alimentos , Resistência à Tração
10.
Environ Monit Assess ; 195(2): 255, 2023 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-36592237

RESUMO

The occurrence and characterization of marine debris on beaches bring opportunities to track back the anthropogenic activities around shorelines as well as aid in waste management and control. In this study, the three largest beaches in Thanh Hoa (Vietnam) were examined for plastic waste, including macroplastics (≥ 5 mm) on sandy beaches and microplastics (MPs) (< 5 mm) in surface water. Among 3803 items collected on the beaches, plastic waste accounted for more than 98%. The majority of the plastic wastes found on these beaches were derived from fishing boats and food preservation foam packaging. The FT-IR data indicated that the macroplastics comprised 77% polystyrene, 17% polypropylene, and 6% high-density polyethylene, while MPs discovered in surface water included other forms of plastics such as polyethylene- acrylate, styrene/butadiene rubber gasket, ethylene/propylene copolymer, and zein purified. FT-IR data demonstrated that MPs might also be originated from automobile tire wear, the air, and skincare products, besides being degraded from macroplastics. The highest abundance of MPs was 44.1 items/m3 at Hai Tien beach, while the lowest was 15.5 items/m3 at Sam Son beach. The results showed that fragment form was the most frequent MP shape, accounting for 61.4 ± 14.3% of total MPs. MPs with a diameter smaller than 500 µm accounted for 70.2 ± 7.6% of all MPs. According to our research, MPs were transformed, transported, and accumulated due to anthropogenic activities and environmental processes. This study provided a comprehensive knowledge of plastic waste, essential in devising long-term development strategies in these locations.


Assuntos
Plásticos , Poluentes Químicos da Água , Vietnã , Espectroscopia de Infravermelho com Transformada de Fourier , Resíduos/análise , Monitoramento Ambiental , Microplásticos , Polietileno/análise , Praias , Poluentes Químicos da Água/análise
11.
Ecotoxicol Environ Saf ; 250: 114500, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36603488

RESUMO

The widespread use but low recovery rate of agricultural films has led to microplastic accumulation in farmlands, which poses a serious threat to the health of the soil ecosystem. There is an urgent need for early warning and monitoring of soil microplastics pollution, as well as the performance of bioremediation research. In this study, earthworms were used as test organisms to carry out toxicological tests under low-density polyethylene (LDPE) stress. A canonical correlation analysis model (CCA) was established to analyze the relationship between oxidative stress and microbial community. A path analysis model (PA) was also constructed to examine the detoxification mechanism of earthworms under LDPE stress. The results showed that low concentrations (100 and 500 mg/kg) of LDPE did not cause oxidative damage to earthworms but stimulated their physiological metabolism. Meanwhile, 1000 mg/kg LDPE concentrations caused oxidative damage to earthworms and altered their internal microbial community structure. Furthermore, at 1500 mg/kg LDPE concentrations, the oxidative stress to the earthworms is aggravated, and their physiological responses work in conjunction with the microbial community to cope with the adverse condition. Lastly, treatment with 2000 mg/kg LDPE induced the appearance of LDPE tolerant populations in the microbial community in vivo. Taken together, our results provide a theoretical basis for revealing the physiological response of earthworms when challenged in a polluted environment and provide a model for pollution remediation and ecological security monitoring of soil ecosystems.


Assuntos
Microbiota , Oligoquetos , Poluentes do Solo , Animais , Polietileno/toxicidade , Polietileno/metabolismo , Plásticos/metabolismo , Oligoquetos/metabolismo , Análise de Correlação Canônica , Poluentes do Solo/análise , Microplásticos/metabolismo , Estresse Oxidativo , Solo/química
12.
Environ Sci Technol ; 57(2): 929-938, 2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36603902

RESUMO

The presence of plastic fragments in the environment is a growing global concern. In this study, we explored the effects of dynamic fluctuations of capillary fringe on the transport of microplastics (MPs) in the substrate combining various environmental and MP properties. Both experimental and Hydrus-2D modeling results confirmed that increasing cycles of water table fluctuation led to the rise of capillary fringe. An increase in the cycles of water table fluctuations did not significantly change the overall MP retention percentages in 0.5 mm substrate but altered the MP distribution along the column. In 1 and 2 mm substrate, the increase in cycle numbers enhanced the MP transport from substrate to the water below. In terms of the size of the MPs, more 20-25 µm polyethylene (PE2) were retained in the substrate compared to 4-6 µm polyethylene (PE1) under the same number of fluctuation cycles. High-density polytetrafluoroethylene (PTFE, 5-6 µm) exhibited higher retention percentages compared to PE1 particles. Ultraviolet aging for 60 days enhanced PE1 transport along the column, while 60 days of seawater aging did not affect PE1 transport greatly. For PTFE, ultraviolet and seawater aging enhanced its retention in the substrate. The retention percentages of both PE1 and PTFE in the column increased with the elevated ionic strength and the decrease of fluctuation velocity. This work highlights that capillary fringe fluctuation can serve as a pathway to relocate MPs to the tidal aquifer.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , Microplásticos , Plásticos/química , Poluentes Químicos da Água/análise , Politetrafluoretileno , Polietileno , Monitoramento Ambiental
13.
Rev Med Liege ; 78(1): 12-16, 2023 Jan.
Artigo em Francês | MEDLINE | ID: mdl-36634060

RESUMO

Total knee replacement (TKR) is currently the gold standard in the surgical management of degenerative knee diseases. It is a reliable operation with 95 % good results at 10 years after surgery. Aseptic loosening is the primary cause of TKR failure. It results from a periprosthetic osteolytic reaction secondary to the host's reaction to the wear particle of the prosthesis and responsible for an imbalance in osteoformation and osteolysis. Polyethylene (PE) is responsible for the majority of periprosthetic reactions but the release of metal particles may play an underestimated role with the risk of systemic manifestations. The first clinical signs appear on average 7 years after prosthesis placement. Radio-clinical assessment may be normal in the early stages. Infectious process must be systematically excluded before concluding to another type of complication.


L'arthroplastie par prothèse totale de genou (PTG) est actuellement l'intervention de référence dans la prise en charge chirurgicale des pathologies dégénératives du genou. C'est une opération fiable, avec 95 % de bons résultats à 10 ans de l'intervention. Le descellement aseptique représente la première cause d'échec d'une PTG. Il résulte d'une réaction ostéolytique périprothétique secondaire à la réaction de l'hôte aux particules d'usure de la prothèse, responsable d'un déséquilibre en ostéoformation et ostéolyse. Le polyéthylène (PE) est responsable de la majorité de ces réactions, mais la libération de particules métalliques pourrait jouer un rôle sous-estimé avec des risques de manifestations systémiques. Les premiers signes cliniques apparaissent en moyenne 7 ans après la mise en place de la prothèse. Le bilan radio-clinique peut être normal au stade débutant. Un processus infectieux doit systématiquement être exclu avant de conclure à un autre type de complication.


Assuntos
Artroplastia do Joelho , Prótese do Joelho , Osteólise , Humanos , Polietileno , Artroplastia do Joelho/efeitos adversos , Prótese do Joelho/efeitos adversos , Falha de Prótese , Articulação do Joelho , Osteólise/etiologia
14.
Huan Jing Ke Xue ; 44(1): 231-242, 2023 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-36635811

RESUMO

This study aimed to explore the occurrence state, morphological characteristics, polymer types, as well as potential ecology of microplastics in the Weihe River in Northwest China. Thus, we identified the abundance distribution, shape, particle size, color, and polymer type of microplastics in the surface water of the Weihe River by conducting field sampling, microscope observation, Fourier infrared spectroscopy, Micro-Raman spectroscopy, etc., during the normal water period (May) of 2021. Subsequently, we analyzed the potential ecological and environmental risks of microplastics using the pollution load index method and species sensitivity distribution method. The results showed that microplastics were detected to exist in all sampling points and the abundance ranged from (2.9±0.8) to (10.3±2.8) n·L-1. The concentration of microplastics in the main stream of the Weihe River was higher than that in the tributaries. Fiber (15.04%-77.03%), small size (<0.5 mm) (27.27%-89.38%), and colored (15.85%-49.53%) were the predominant microplastic types. Polyethylene (32.98%), polypropylene (29.79%), polystyrene (21.21%), and polyethylene (10.61%) terephthalate were the main types of polymers detected. In general, the microplastic pollution in Weihe River was at a medium level and had not affected aquatic organisms, but its high concentration and the characteristic of the plastics to adsorb other pollutants are still of concern.


Assuntos
Microplásticos , Poluentes Químicos da Água , Plásticos , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Polietileno , China , Água
15.
J Orthop Surg Res ; 18(1): 24, 2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36627685

RESUMO

BACKGROUND: The risks of metal release due to fretting and corrosion at the head-neck junction and consequent adverse local tissue reaction (ALTR) have concerns in metal-on-polyethylene (MoP) total hip arthroplasty (THA). Although trunnions have become thinner in diameter to increase the range of motion, it has remained unclear whether this change affects metal release and ALTR in vivo. This study aimed to investigate serum metal concentrations and the prevalence of ALTR in MoP THA with a 9/10-mm stem trunnion. PATIENTS AND METHODS: A consecutive series of 37 hips that underwent THA using MoP grafted with poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) with a 9/10-mm trunnion stem were retrospectively reviewed. Serum metal levels were assessed and compared with those in MoP THA with a 10/12-mm trunnion stem. ALTR was diagnosed with serum metal levels and cross-sectional images. The factors associated with serum metal levels were also assessed. RESULTS: The median serum cobalt and chromium levels were 1.5 µg/L and 1.0 µg/L in the 9/10-mm group and 0.2 µg/L and 0.4 µg/L in the 10/12-mm group, respectively. ALTR was found in 5 hips of 3 patients. Revision surgery was performed in 4 hips, and all stem trunnions and femoral heads showed severe corrosion. Postoperative walking ability was associated with serum metal levels. CONCLUSION: It was found that a 9/10-mm stem trunnion with MoP grafted with PMPC had high risks of metal release in primary THA. Careful follow-up and cross-sectional imaging are needed to detect ALTR for early revision.


Assuntos
Artroplastia de Quadril , Prótese de Quadril , Humanos , Artroplastia de Quadril/efeitos adversos , Polietileno , Prótese de Quadril/efeitos adversos , Estudos Retrospectivos , Falha de Prótese , Metais , Cobalto , Reoperação/efeitos adversos , Desenho de Prótese
16.
Water Sci Technol ; 87(1): 99-114, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36640026

RESUMO

Microplastic (MP) pollution has been rising as a threatening risk and recently has appealed to the attention of more researchers. In this study, influential parameters affecting the removal rate of polyethylene microplastics (PEMPs) were optimized through response surface methodology (RSM). In Box Behnken Design (BBD), independent parameters were pH, PEMP size, coagulant dosage and polyacrylamide dosage. Two experimental sets were conducted, one with ferric chloride and the second with poly aluminum chloride as two commonly applied coagulants in drinking water treatment plants (DWTPs). Comparing the results of optimized parameters, PAC was a better coagulant with the predicted removal rate of 58.19%, while the removal rate with ferric chloride as a coagulant was predicted to be 56.37%. Moreover, some experiments were conducted to analyze the effect of ozone gas and sodium hypochlorite as disinfectants on removal rate. The highest removal rate was observed when 2 ppm of O3 was added to the solution coagulated with optimal dosage of PAC, reaching the removal rate of 76.8%.


Assuntos
Desinfetantes , Poluentes Químicos da Água , Purificação da Água , Microplásticos , Plásticos , Polietileno , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Floculação
17.
Water Sci Technol ; 87(1): 115-129, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36640027

RESUMO

Microplastics (MPs) are an issue of prime environmental concern globally. The abundance of MP particles in the informal open solid waste landfill soil was evaluated showing 180-1120 MP particles per kg of soil. Moisture content (MC), electrical conductivity (EC) and pH of the MP-contaminated soil compared to the baseline showed 2.96% MC, 187-441 µS/cm EC and 6.94 pH. Morphology of extracted MPs in SEM showed particle fragmentation as film fragments (13.7%), fragments (56.1%), fibres (26.4%) and foam (3.8%). EDS results showed Carbon 71.8% and 24.5% oxygen with traces of Na, Al, Si and Cl-. FTIR of field obtained MPs identified were polyethylene and polypropylene. The association of MP particles with COD and chloride was discovered. MP particles of Low-density Polyethylene of size of 1 mm × 1 mm and thickness 25 µm up to 20 numbers showed no effect adding to the COD values. The COD values increased with increase in MP particle numbers. Similarly, chloride associations with MP particles showed an increase in MP particles reducing chloride values by 31% in landfill runoff water. It is interpreted that MP particle disintegration into nano-sized plastics (NPs) in the soil/runoff water can greatly increase the COD values and impair the salt mass balance.


Assuntos
Microplásticos , Poluentes Químicos da Água , Microplásticos/química , Plásticos , Cloretos , Resíduos Sólidos , Solo , Poluentes Químicos da Água/análise , Polietileno/análise , Água , Monitoramento Ambiental
18.
J Environ Manage ; 329: 117044, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36584507

RESUMO

Photodegradation of plastic in solid-phase requires the polymer to be composited with an efficient photocatalyst. We report herein the successful synthesis and characterization of fluoride-doped-TiO2 and its applicability, for the first time, on solid-phase photodegradation of polyethylene films. Nearly half weight loss of polyethylene, containing only 2% of the photocatalyst, is eliminated after three weeks of ultraviolet A radiation using a low consumption light emitting diode lamp, defeating previously reported data. The half-life time of the plastic was around 3 weeks, highlighting the viability of this process for real applications. Results were compared to raw PE and PE composite with well-known TiO2, resulting in, respectively, 0 and 26% of weight loss. The degradation process was monitored by optical microscopy, scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, Fourier transform infrared and X-ray photoelectron spectroscopy, which revealed the formation of plastic cracks, loss of polyethylene crystallinity and thus stability, the oxidation of C-H bonds and the oxidized state of the surface compounds during photodegradation. The obtained results open a path for the future production of cleaner and self-photodegradable plastics, where the photocatalyst would be introduced in all the manufactured plastics, making possible the quicker photodegradation of the plastics that end up on the environment and the plastics reaching wastewater treatment plants.


Assuntos
Polietileno , Raios Ultravioleta , Fluoretos , Titânio/química , Catálise
19.
Environ Pollut ; 319: 120977, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36586558

RESUMO

Microplastics have been widely reported as carriers of antibiotics, yet studies investigating the combined ecotoxicology of microplastics and antibiotics on organisms is limited. In this study, different sized polystyrene plastics and oxytetracycline (OTC) were used to carry out a 30-day single and binary-combined exposure experiment of zebrafish, and the microplastics and OTC accumulation, liver histological alteration, biomarkers and transcriptomic response of zebrafish were evaluated. Our results indicated that 300 nm and 50 nm plastic particles increased the OTC accumulation in liver by 33.8% and 44.5%, respectively. Microplastics and OTC induced severe liver histological damage, and the damage is size-dependent, increasing with the decrease of microplastics sizes. The liver biomarkers indicated a different response pattern in single microplastics exposure and combined with OTC, single or co-exposure of 50 nm nano-plastics and OTC induced intense responses of integrated biomarker response values. The 50 nm nano-plastics, OTC and their combined exposure induced 1330, 2693 and 3965 significantly differentially expressed genes, respectively, in which the steroid biosynthesis pathway was significantly affected by all the three treatments. This study elucidated the size-dependent effects of microplastics and provided detailed data from histopathology to transcriptome profile, enhancing our understanding of the ecotoxicity of microplastics and OTC.


Assuntos
Oxitetraciclina , Poluentes Químicos da Água , Animais , Peixe-Zebra/fisiologia , Oxitetraciclina/toxicidade , Polietileno , Microplásticos/toxicidade , Ecotoxicologia , Plásticos , Antibacterianos/toxicidade , Poliestirenos , Biomarcadores , Poluentes Químicos da Água/toxicidade , Poluentes Químicos da Água/análise
20.
J Chem Inf Model ; 63(1): 76-86, 2023 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-36475723

RESUMO

Permeation through polymer membranes is an important technology in the chemical industry, and in its design, the self-diffusion coefficient is one of the physical quantities that determine permeability. Since the self-diffusion coefficient sensitively reflects intra- and intermolecular interactions, analysis using an all-atom model is required. However, all-atom simulations are computationally expensive and require long simulation times for the diffusion of small molecules dissolved in polymers. MD-GAN, a machine learning model, is effective in accelerating simulations and reducing computational costs. The target systems for MD-GAN prediction were limited to polyethylene melts in previous studies; therefore, this study extended MD-GAN to systems containing copolymers with branches and successfully predicted water diffusion in various polymers. The correlation coefficient between the predicted self-diffusion coefficient and that of the long-time simulation was 1.00. Additionally, we found that incorporating statistical domain knowledge into MD-GAN improved accuracy, reducing the mean-square displacement prediction outliers from 14.6% to 5.3%. Lastly, the distribution of latent variables with embedded dynamics information within the model was found to be strongly related to accuracy. We believe that these findings can be useful for the practical applications of MD-GAN.


Assuntos
Simulação de Dinâmica Molecular , Polímeros , Polímeros/química , Água/química , Difusão , Polietileno
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