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Environmental Toxicology and Chemistry Oct 2022Numerous per- and polyfluoroalkyl substances (PFAS) are of growing concern worldwide due to their ubiquitous presence, bioaccumulation and adverse effects. Surface...
Numerous per- and polyfluoroalkyl substances (PFAS) are of growing concern worldwide due to their ubiquitous presence, bioaccumulation and adverse effects. Surface waters in the United States have displayed elevated concentrations of PFAS, but so far discrete water sampling has been the commonly applied sampling approach. In the present study we field-tested a novel integrative passive sampler, a microporous polyethylene tube, and derived sampling rates (R ) for nine PFAS in surface waters. Three sampling campaigns were conducted, deploying polyethylene tube passive samplers in the effluent of two wastewater treatment plant (WWTP) effluents and across Narragansett Bay (Rhode Island, USA) for 1 month each in 2017 and 2018. Passive samplers exhibited linear uptake of PFAS in the WWTP effluents over 16-29 days, with in situ R for nine PFAS ranging from 10 ml day (perfluoropentanoic acid) to 29 ml day (perfluorooctanesulfonic acid). Similar sampling rates of 19 ± 4.8 ml day were observed in estuarine field deployments. Applying these R values in a different WWTP effluent predicted dissolved PFAS concentrations mostly within 50% of their observations in daily composite water samples, except for perfluorobutanoic acid (where predictions from passive samplers were 3 times greater than measured values), perfluorononanoic acid (1.9 times), perfluorodecanoic acid (1.7 times), and perfluoropentanesulfonic acid (0.1 times). These results highlight the potential use of passive samplers as measurement and assessment tools of PFAS in dynamic aquatic environments. Environ Toxicol Chem 2022;41:2375-2385. © 2022 SETAC.
Topics: Environmental Monitoring; Fluorocarbons; Polyethylene; Water; Water Pollutants, Chemical
PubMed: 35833595
DOI: 10.1002/etc.5431 -
Scientific Reports Sep 2023Microplastic (MP) pollution in agricultural soils, resulting from the use of plastic mulch, compost, and sewage sludge, jeopardizes the soil microbial populations....
Microplastic (MP) pollution in agricultural soils, resulting from the use of plastic mulch, compost, and sewage sludge, jeopardizes the soil microbial populations. However, the effects of MPs on soil chemical properties and microbial communities remain largely unknown. Here, we investigated the effects of different concentration levels (0, 0.1, 1, 3, 5, and 7%; w:w) of low-density polyethylene (LDPE) MPs on the chemical properties and bacterial communities of agricultural soil in an incubation study. The addition of LDPE MPs did not drastically change soil pH (ranging from 8.22 to 8.42). Electrical conductivity increased significantly when the LDPE MP concentrations were between 1 and 7%, whereas the total exchangeable cations (Na, K, Mg, and Ca) decreased significantly at higher LDPE MP concentrations (3-7%). The highest available phosphorus content (2.13 mg kg) was observed in 0.1% LDPE MP. Bacterial richness (Chao1 and Ace indices) was the lowest at 0.1% LDPE MP, and diversity indices (Shannon and Invsimpson) were higher at 0 and 1% LDPE MP than at other concentrations. The effect of LDPE MP concentrations on bacterial phyla remained unchanged, but the bacterial abundance varied. The relative abundance of Proteobacteria (25.8-33.0%) was the highest in all treatments. The abundance of Acidobacteria (15.8-17.2%) was also high, particularly in the 0, 0.1, and 1% LDPE MPs. With the increase in LDPE MP concentration, the abundance of Actinobacteria gradually increased from 7.80 to 31.8%. Our findings suggest that different MP concentration levels considerably alter soil chemical properties and microbial composition, which may potentially change the ecological functions of soil ecosystems.
Topics: Microplastics; Soil; Plastics; Polyethylene; Microbiota; Bacteria
PubMed: 37770500
DOI: 10.1038/s41598-023-42285-w -
Journal of Pharmaceutical Sciences Jul 2020Semifluorinated alkanes (SFAs) are aprotic solvents, which may be used as drug solvents for topical ocular applications, for instance, in dry eye syndrome. Their...
Semifluorinated alkanes (SFAs) are aprotic solvents, which may be used as drug solvents for topical ocular applications, for instance, in dry eye syndrome. Their physical properties suggest that they might be prone to interaction with plastic materials, such as, polyethylene (PE) and polypropylene (PP), which are commonly used as packaging materials for pharmaceutical products. In this study, we investigate interactions of PE and PP with a liquid SFA perfluorohexyloctane (PFHO) using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and cross-polarized light microscopy. Binary phase diagrams of PFHO-PE and PFHO-PP systems demonstrating interactions of PFHO with the polymeric materials were constructed based on DSC data. According to this data, PFHO tends to lower the melting temperatures of PE and PP. The equilibrium values of solubilities of the polymers in PFHO and PFHO in the polymers were obtained by extrapolation of melting enthalpy data. Absorption of PFHO by PE and PP materials at ambient conditions after 4 weeks of equilibration was also studied by TGA. From the presented results, it may be concluded that thorough studies of interactions of PE or PP with SFAs are required when these materials are used as packaging components in SFA-based formulations.
Topics: Fluorocarbons; Pharmaceutical Preparations; Polyethylene; Polypropylenes
PubMed: 32240694
DOI: 10.1016/j.xphs.2020.03.026 -
Acta Ortopedica Mexicana 2010
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Acta Ortopedica Mexicana 2010
Review
Topics: Chemical Phenomena; History, 20th Century; Mechanical Phenomena; Osteolysis; Polyethylene; Product Packaging; Sterilization; Vitamin E
PubMed: 20836377
DOI: No ID Found -
Journal of Infection in Developing... Mar 2013Contaminated sponges might lead to cross-contamination in kitchens since they can transfer microorganisms to surfaces where microorganisms can survive for hours or days...
INTRODUCTION
Contaminated sponges might lead to cross-contamination in kitchens since they can transfer microorganisms to surfaces where microorganisms can survive for hours or days and contaminate food. The main objective of this study was to evaluate the transfer and the survival of bacteria from kitchen sponges to surfaces of AISI 316 stainless steel and polyethylene.
METHODOLOGY
Twenty-four sponges were collected from industrial kitchens in the state of Rio Grande do Sul and aseptically split into two equal parts. One part was subjected to enumeration of heterotrophic microorganisms, faecal coliforms, coagulase-positive Staphylococcus and search detection of Salmonella enterica. The other part was rubbed on surfaces of AISI 316 stainless steel (12 sponges) or polyethylene (12 sponges). The transfer and survival of microorganisms was quantified by swab collection and pour-plate method using plate count agar.
RESULTS
All sponges were contaminated by heterotrophic microorganisms (average of 6.8 log CFU/sponge) and 83.3% with faecal coliforms (average of 5 log CFU/sponge). None of the sponges were contaminated by S. enterica and/or coagulase-positive Staphylococcus. The average transfer of microorganisms varied between 3.3 and 5.5 log CFU/cm2 for stainless steel and from 3.5 to 5.6 log CFU/cm2 for polyethylene. Although the survival rate decreased over time, more than 1 log CFU/cm2 of heterotrophic microorganisms survived after 24 hours on both surfaces.
CONCLUSIONS
The sponges used in food services were significantly contaminated and could transfer large amounts of microorganisms to surfaces of AISI 316 stainless steel and polyethylene.
Topics: Bacteria; Bacterial Load; Environmental Microbiology; Food Handling; Humans; Microbial Viability; Polyethylene; Stainless Steel
PubMed: 23493001
DOI: 10.3855/jidc.2472 -
Proceedings of the Institution of... Nov 2019Evaluation and prediction of wear play a key role in product design and material selection of total hip replacements, because wear debris is one of the main causes of... (Review)
Review
Evaluation and prediction of wear play a key role in product design and material selection of total hip replacements, because wear debris is one of the main causes of loosening and failure. Multifactorial clinical or laboratory studies are high cost and require unfeasible timeframes for implant development. Simulation using finite element methods is an efficient and inexpensive alternative to predict wear and pre-screen various parameters. This article presents a comprehensive literature review of the state-of-the-art finite element modelling techniques that have been applied to evaluate wear in polyethylene hip replacement components. A number of knowledge gaps are identified including the need to develop appropriate wear coefficients and the analysis of daily living activities.
Topics: Arthroplasty, Replacement, Hip; Finite Element Analysis; Humans; Mechanical Phenomena; Polyethylene
PubMed: 31466506
DOI: 10.1177/0954411919872630 -
Orthopaedics & Traumatology, Surgery &... Feb 2023Slightly more than 20 years after its first clinical use, highly cross-linked polyethylene (HXLPE) has been widely adopted. Despite initial concerns about oxidation and... (Review)
Review
Slightly more than 20 years after its first clinical use, highly cross-linked polyethylene (HXLPE) has been widely adopted. Despite initial concerns about oxidation and lack of fatigue resistance, first generation HXLPE, with 15 years of follow-up and widespread use, continues to provide excellent results, even in a young, active population. Remelted HXLPE might have a lower wear rate than annealed HXLPE and will no doubt have a better resistance to oxidation. Second generation materials, consisting of polyethylene (PE) that is sequentially irradiated then annealed and PE that is infused with antioxidants, also have provided encouraging short- and medium-term results. Data from national joint registers confirm data from clinical trials. Even in more challenging cases (dual mobility, hip resurfacing, revision surgery and thin liners), HXLPE has generated promising results. However, failures (rim fractures) have been documented, including for all the latest HXLPE generations. Consequently, certain precautions must be taken during its use and close patient monitoring is necessary.
Topics: Humans; Arthroplasty, Replacement, Hip; Polyethylene; Hip Prosthesis; Prosthesis Failure; Prosthesis Design
PubMed: 36302450
DOI: 10.1016/j.otsr.2022.103457 -
Molecules (Basel, Switzerland) Jul 2022It is inevitable that reclaimed cotton stalks will contain a certain amount of plastic film due to the wide application of plastic mulching during the process of cotton...
It is inevitable that reclaimed cotton stalks will contain a certain amount of plastic film due to the wide application of plastic mulching during the process of cotton cultivation, and this makes it inappropriate to return it to the field or for it to be processed into silage. In this study, biochars were prepared by the co-pyrolysis of cotton stalk with low-density polyethylene (LDPE) in the proportions of 1:0, 3:1, 2:1, and 1:1 (/) at 400 °C, 450 °C, and 500 °C and maintaining them for 1 h. The effects of the co-pyrolysis of cotton stalk with LDPE on the properties of biochars (e.g., pH, yield, elemental analysis, specific surface area, etc.) and the Pb(II) removal capacity were analyzed. Co-pyrolysis cotton stalks with LDPE could delay the decomposition of LDPE but could promote the decomposition of cotton stalk. At 400 °C and 450 °C, the addition of LDPE decreased the H/C ratio, while no significant difference was found between the pristine biochar and the blended biochar pyrolyzed at 500 °C. An FTIR analysis indicated that the surface functional groups of biochar were not affected by the addition of LDPE, except for CH and CH. The results of the SEM showed that LDPE could cover the surface of biochar when pyrolyzed at 400 °C, while many macropores were found in the blended biochar that was pyrolyzed at 450 °C and 500 °C, thus increasing its surface area. The blended biochar that was pyrolyzed at 500 °C was more effective in the removal of Pb(II) than the cotton-stalk-derived biochar, which was dominated by monolayer adsorption with a maximum adsorption capacity of approximately 200 mg·g. These results suggested that the co-pyrolysis of cotton stalks and LDPE may be used to produce biochar, which is a cost-effective adsorbent for heavy metal removal from aqueous solutions.
Topics: Adsorption; Charcoal; Lead; Polyethylene; Pyrolysis
PubMed: 35956817
DOI: 10.3390/molecules27154868 -
The Bone & Joint Journal Jan 2016The 'jumbo' acetabular component is now commonly used in acetabular revision surgery where there is extensive bone loss. It offers high surface contact, permits weight... (Review)
Review
The 'jumbo' acetabular component is now commonly used in acetabular revision surgery where there is extensive bone loss. It offers high surface contact, permits weight bearing over a large area of the pelvis, the need for bone grafting is reduced and it is usually possible to restore centre of rotation of the hip. Disadvantages of its use include a technique in which bone structure may not be restored, a risk of excessive posterior bone loss during reaming, an obligation to employ screw fixation, limited bone ingrowth with late failure and high hip centre, leading to increased risk of dislocation. Contraindications include unaddressed pelvic dissociation, inability to implant the component with a rim fit, and an inability to achieve screw fixation. Use in acetabulae with < 50% bone stock has also been questioned. Published results have been encouraging in the first decade, with late failures predominantly because of polyethylene wear and aseptic loosening. Dislocation is the most common complication of jumbo acetabular revisions, with an incidence of approximately 10%, and often mandates revision. Based on published results, a hemispherical component with an enhanced porous coating, highly cross-linked polyethylene, and a large femoral head appears to represent the optimum tribology for jumbo acetabular revisions.
Topics: Acetabulum; Arthroplasty, Replacement, Hip; Bone Screws; Hip Prosthesis; Humans; Polyethylene; Prosthesis Design; Reoperation
PubMed: 26733644
DOI: 10.1302/0301-620X.98B1.36139