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The results of the thermalized flux calculation that incorporate radiative capture reactions in the presence and absence of polyethylene blocks that form an enclosure for a deuteron-deuteron (D-D) neutron generator are presented. This method can be used to measure the moderated neutron flux component in a mixture of moderated and primary neutron spectra. Using 20-cm-thick polyethylene blocks to surround a D-D neutron generator, the moderation of primary neutrons was investigated using nine indium foils. In this paper, the relationship between the moderated neutron flux and the radiative capture rates in the presence and absence of polyethylene blocks is derived. This is compared to a MCNP simulation and a calculation of modulated flux that ignore the primary neutron components. [ABSTRACT FROM AUTHOR]

Today, due to the presence of various microbial species and the reduction in healthcare costs, the use of antimicrobial materials has become indispensable for human society. Silver is the most widely used and effective antimicrobial agent, capable of penetrating bacterial structures and disrupting their biological systems. Among all methods of employing silver ions, the selection of zeolites, such as natural clinoptilolite with a crystalline aluminosilicate structure, hydrated, finely porous, and highly water-absorbent due to the ion release mechanism, has garnered significant attention. Heavy polyethylene is one of the corrosion-resistant polymers produced in Iran, offering insulation, quality, and costeffectiveness. Due to its non-toxic nature and minimal environmental concerns, it has gained considerable attention. This research introduced silver ions into the porous zeolite network through an ion exchange mechanism. Subsequently, composite polyethylene coatings containing 0%, 10%, and 20% by weight of silver zeolite were applied on the 304 AISI stainless steel substrate using dip coating method. The coatings were then characterized through X-ray diffraction and scanning electron microscopy. The results indicated that with an increase in silver zeolite content within the polyethylene matrix, the coatings became more homogeneous, thicker, and corrosion-resistant. After applying the coatings, their corrosion behavior in a 3.5% wt.% NaCl environment was studied during 10, 24, 40, 70, and 100 days using electrochemical impedance spectroscopy. According to the results of electrochemical impedance spectroscopy, adding silver zeolite to polyethylene coatings up to 10 wt.% reduced corrosion resistance, while adding 20 wt.% increased corrosion resistance in the scratch-resistant coatings. Finally, by exposing the samples to a bacterial environment containing gram-negative (Escherichia coli) and gram-positive (Staphylococcus aureus) bacteria, their antimicrobial properties were evaluated for potential antibacterial applications. The results from the halo and colony count tests suggested an improvement in antimicrobial efficacy against Staphylococcus aureus compared to Escherichia coli with increasing content of silver zeolite. [ABSTRACT FROM AUTHOR]

Objectives: To assess the overall mental health of enucleated or eviscerated patients after high-density porous polyethylene OCULFIT implantation and external prosthesis over a 1-year follow-up. Methods: Patients with an indication of enucleation or evisceration with OCULFIT implantation were included in a prospective study. The patients completed four questionnaires regarding mental health at three different visits (baseline, 3–6 months, and 9–12 months post-surgery). The questionnaires used were the following: SF-12 for multidimensional health-related quality of life (scale 0–100); Rosemberg self-esteem scale (scale 0–40); Patients Health Questionnaire-4 (PHQ-4) (scale 0–6); and a Lifetime Major Depression and Anhedonia questionnaire (categorised in groups with/without symptoms). Results: A total of 33 patients (16 enucleations and 17 eviscerations) were included in the study. The physical domain of the SF-12 questionnaire did not change between visits, but the mental domain significantly improved from the baseline to the last visit (41.71 ± 12.72 vs. 46.80 ± 10.68, p = 0.04). The number of patients with high, moderate, and low self-esteem (Rosemberg scale) was similar between the baseline and the last visit. The depression and anxiety scores of the PHQ-4 were not significantly different among visits. The number of patients with no symptoms (depression or anhedonia) improved from the baseline (42.2%) throughout the follow-up (66.7% at the last visit). Conclusions: OCULFIT orbital implant and external prosthesis placement maintained and/or improved the quality of life related to mental health in eviscerated and enucleated eyes. The number of patients with no symptoms improved from the baseline throughout the follow-up. The patients' self-esteem was already high before implantation and remained stable over the follow-up. [ABSTRACT FROM AUTHOR]

The aim of this project was to assess the thermal conductivity of polyethylene (PE) filled with carbon black (CB), specifically for geothermal pipes. The project explored the potential modification of PE's thermal conductivity by incorporating recycled textile fibers. Different types of shredded recycled fibers were tested, including two types of polyamide fibers with varying contaminations and one type of polyester fiber. Following several preparation steps, various composite materials were manufactured and compared to bulk PE using various testing methods: Differential Scanning Calorimetry analysis (DSC), mechanical testing (flexural and tensile), and laser flash analysis (LFA). The results revealed alterations in the mechanical properties of the composite materials in comparison to PE filled with CB. The LFA tests demonstrated the effectiveness in reducing polymer thermal diffusivity at higher temperatures, particularly when the material was loaded with recycled polyester fillers. [ABSTRACT FROM AUTHOR]

The tensile properties and the Weibull statistical distributions of the tensile strength of poly-(para-phenylene-2,6-benzobisoxazole) (PBO), poly-(para-phenylene terephthalamide) (PPTA), copoly-(para-phenylene-3,4′-oxydiphenylene terephthalamide (PPODTA), polyarylate (PAR), and polyethylene (PE) polymeric fiber epoxy-impregnated bundle composites have been investigated. The results show that the Weibull modulus decreases as the tensile modulus, strength, and inverse of the failure strain increase. The interfacial shear properties were also examined using the microdroplet composite. For the lower interfacial shear strength of polymeric fibers, the Weibull modulus decreases as interfacial shear strength increases. Conversely, for the higher interfacial shear strength of polymeric fibers, the Weibull modulus increases as interfacial shear strength increases. Interestingly, these inflection points were also observed for the 20–30 MPa interfacial shear strength. [ABSTRACT FROM AUTHOR]

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Plastic pollution poses a significant environmental challenge. In this study, the strain Enterobacter cloacae O5-E, a bacterium displaying polyethylene-degrading capabilities was isolated. Over a span of 30 days, analytical techniques including x-ray diffractometry, scanning electron microscopy, optical profilometry, hardness testing and mass spectrometric analysis were employed to examine alterations in the polymer. Results revealed an 11.48% reduction in crystallinity, a 50% decrease in hardness, and a substantial 25-fold increase in surface roughness resulting from the pits and cracks introduced in the polymer by the isolate. Additionally, the presence of degradational by-products revealed via gas chromatography ascertains the steady progression of degradation. Further, recognizing the pivotal role of alkane monooxygenase in plastic degradation, the study expanded to detect this enzyme in the isolate molecularly. Molecular docking studies were conducted to assess the enzyme's affinity with various polymers, demonstrating notable binding capability with most polymers, especially with polyurethane (− 5.47 kcal/mol). These findings highlight the biodegradation potential of Enterobacter cloacae O5-E and the crucial involvement of alkane monooxygenase in the initial steps of the degradation process, offering a promising avenue to address the global plastic pollution crisis. [ABSTRACT FROM AUTHOR]

The increasing awareness of the potential health risks associated with microplastics' (MPs) and nanoplastics' (NPs) presence in the environment has led to a significant rise in research focused on these particles over the past few years. This review focuses on the research on MPs'/NPs' presence and spread, pathways of exposure, toxicological effects on human health and legal framework related to MP/NP challenges. Several research projects have aimed to assess their potential harm to human health, focusing on different systems and organs. After exposure (independent of the pathway), these hazards reach the blood stream and concentrate in different organs. Further, they are responsible for harmful changes, having an immediate effect (pain, inflammation, or hormone imbalance) or lead to a long-term disease (e.g., infertility, chronic obstructive pulmonary disease, or cancer). Toxicological effects have been noticed at high concentrations of MPs, specifically polystyrene, the most widespread typical MP, but only short-term effects have been mostly studied. Significant quantities of consumed MPs have been discovered to have diverse detrimental effects, posing a threat to human welfare. The exact concentrations of microplastics that are inhaled and swallowed and then build up in the human body are still not known. Further investigation is necessary to evaluate the impact of MP/NP contamination at minimal concentrations and for prolonged durations. [ABSTRACT FROM AUTHOR]

An experimental evaluation of the decrease in actual physical and mechanical characteristics of low pressure polyethylene (HDPE) pipes depending on the duration and conditions of their operation has been conducted. To assess the impact of operational factors on the pipe characteristics, the following parameters were determined: tensile elongation and tensile strength, thermal stability (induction period of oxidation (IPO) of the material), and degree of crystallinity. It was found that, after prolonged operation of HDPE pipes compared to the initial normative values, the most significantly affected parameters are the tensile elongation and the induction period of oxidation. Moreover, the changes in tensile elongation and IPO parameters have a similar nature in terms of the loss of properties, indicating a correlation between them. The most sensitive indicators for predicting the service life of HDPE pipes are the tensile elongation and the induction period of oxidation. On the basis of the data obtained, it seems promising to monitor the IPO value when determining the technical condition of polyethylene pipes. A calculated forecast of the service life of polyethylene pipes based on reaching their ultimate state has been performed. [ABSTRACT FROM AUTHOR]

Purpose: To assess the fracture resistance and failure mode of endodontically treated premolars reconstructed by different preparation approaches: cervical margin relocation (CMR) and crown lengthening (CL) with complete ferrule (CLF) and partial ferrule (CLPF) with three different post and core systems. Materials and Methods: In this in vitro study, 100 maxillary premolars were assigned to the following 10 groups according to their preparation approach and type of post and core system (n = 10): (I) control (intact teeth), (II) prefabricated fiber post (PFP) and composite core with CMR (PFP‐CMR), (III) polyethylene fiber‐reinforced composite (PEFRC) with CMR (PEFRC‐CMR), (IV) casting post (CP) and core with CMR (CP‐CMR), (V) PFP‐CLPF, (VI) PEFRC‐CLPF, (VII) CP‐CLPF, (VIII) PFP‐CLF, (IX) PEFRC‐CLF, and (X) CP‐CLF. After thermomechanical loading, the fracture resistance and failure mode were assessed. Data were analyzed statistically (α = 0.05). Results: In all post and core systems, the CLPF approach had lower fracture resistance than CMR (p < 0.05); CLF showed higher fracture resistance than CLPF only in the PFP system (p = 0.038). In PEFRC and CP systems, the difference between CLF and CLPF was not significant (p > 0.05). No significant difference was found in fracture resistance of different post and core systems with the same preparation approach (p > 0.05). CLPF showed the highest frequency of favorable, and CLF showed the highest frequency of unfavorable fractures. Conclusion: CLPF yielded lower fracture resistance than CMR. The difference in fracture resistance was not significant between CLF and CMR but the frequency of unfavorable fractures was higher in CLF than in other groups. [ABSTRACT FROM AUTHOR]

Reintroducing recycled plastics into production processes can lead to irreversible degradation and changes in their properties, thereby limiting their recycling potential to a finite number of loops. This study investigates the impact of process-induced degradation resulting from multiple reprocessing cycles on specific material properties and aims to establish structure–property relationships. Four different polyolefins, including two polypropylenes, high-density polyethylene, and low-density polyethylene, were selected for the study. The materials underwent extrusion, pelletizing, injection molding, and milling before being reintroduced into the reprocessing cycle. This sequence of processing steps was repeated six times on each material. Various characterization techniques, including high-temperature gel permeation chromatography, melt mass flow rate, parallel-plate rheology, differential scanning calorimetry, gas chromatography–mass spectrometry, and optical defect control system, were performed to evaluate the molecular structure, rheological behavior, thermal stability, and the resulting contaminants and defects after each reprocessing step. The reprocessing of polypropylene resulted in a gradual decrease in the average molecular weights accompanied by a shift to lower viscosities and higher melt mass flow rates, whereas the polyethylene grades showed the opposite trend with a less pronounced effect in high-density polyethylene. The volatile organic compounds rose in polypropylene and sank in polyethylene after reprocessing. Additionally, all four materials exhibited an increase in degradation-related defects based on optical defect analysis. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are a potential threat to the marine environment and its associated ecosystem functions. Earlier investigations revealed that the microbiome plays a crucial role in deciding the fate of MPs in the environment. Further studies also highlighted the influences of environment and polymer types on the plastisphere microbiome. Nevertheless, the major factor that determines the plastisphere microbiome remains elusive. Thus, we examined the publicly available marine plastisphere data generated from polyethylene (PE), polypropylene (PP), and polystyrene (PS), collected from three different locations to identify the importance of environment and/or polymer types in shaping the microbiome. The beta diversity analyses showed a clear distinction between samples collected from different locations. The PERMANOVA results illustrated a significant influence of environment and sample type (control/PE/PP/PS) on the microbial communities. However, the influence of sample type on microbial diversity was not significant (P-value > 0.05) when the control samples were removed from the dataset but the environment remained a significant factor (P-value < 0.05). Further, the differential abundance analyses explicitly showed the abundance of many bacterial taxa to be significantly influenced (adjusted P-value < 0.05) by the locations rather than the polymer types. The validation analysis also supports the findings. Thus, this study suggests that both the surrounding environment and polymer types determine the microbial communities on marine MPs, but the role of the environment in shaping the microbial composition is greater than that of polymer types. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are tiny plastic particles ranging from 1 to 5000 μm in size and are of particular concern nowadays because of their ecological risk & health concerns. MPs are prevalent environmental contaminants and have been reported in various ecosystems such as soil, air, water, and road dust. However, a thorough understanding of their distribution across various environmental matrices remains elusive. Therefore, this review aims to fill this knowledge gap by examining the abundance of MPs and different techniques utilized for their identification and characterization including sampling, extraction, identification, characterization, and quantification methods. MPs possess a large surface area and exhibit hydrophobic properties, providing a substrate for environmental pollutants such as Polyaromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs). The primary mechanisms through which pollutants attached to MPs are hydrophobic interactions, electrostatic attraction, hydrogen bonding, halogen bonding, and π-π interactions. Therefore, a better understanding of these interactions is crucial for determining the fate and transport of MPs and co-contaminants in the environment. Researchers commonly deploy techniques such as stereomicroscopy and spectroscopy for the characterization and quantification of MPs. However, size and chemical properties of MPs pose a challenge in their quantification, thereby necessitating the development of standardized analytical methods. Use of bio-indicators for MPs biomonitoring has gained popularity in recent years as an affordable option over conventional techniques however research in this area is limited. With this intention, the present review is designed to provide information about the status of the field and advance our knowledge of MPs in various environmental matrices. Highlights: • Soil and road dust are one of the major sources of MPs for aquatic ecosystem. • Fibers of polypropylene & polyethylene are the most abundant MPs in soil & aquatic systems and show pollutant adsorption. • Biomonitoring of MPs emerges as a new alternative for their quantification. [ABSTRACT FROM AUTHOR]

Hydrogenolysis has been explored as a promising approach for plastic chemical recycling. Noble metals, such as Ru and Pt, are considered effective catalysts for plastic hydrogenolysis, however, they result in a high yield of low-value gaseous products. In this research, an efficient bimetallic catalyst was developed by separate impregnation of Ni and Ru on SiO2 support resulting in liquid products yield of up to 83.1 C % under mild reaction conditions, compared to the 65.5 C % yield for the sole noble metal catalyst. The carbon distribution of the liquid products from low density polyethylene hydrogenolysis with Ni-modified catalyst also shifted to a heavier fraction, compared to that with Ru catalyst. Meanwhile, the NiRu catalyst exhibited excellent performance in suppressing the cleavage of the end-chain C–C bond, leading to a methane yield of only 10.4 C %, which was 69% lower than that of the Ru/SiO2 catalyst. Temperature programmed reduction and desorption of hydrogen and propane were further conducted to reveal the detailed mechanism of low density polyethylene hydrogenolysis over the bimetallic catalyst. The results suggested that the Ni-Ru alloy exhibited stronger H adsorption properties indicating improved hydrogen coverage on the catalyst surface thus enhancing the desorption of reaction intermediates. The carbon number distribution was ultimately skewed toward heavier liquid products. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of the stress evolution of high‐density polyethylene (HDPE) at loading, relaxation, and recovery stages in a multi‐relaxation‐recovery (RR) test. The analysis is based on a three‐branch spring‐dashpot model that uses the Eyring's law to govern the viscous behavior. The spring‐dashpot model comprises two viscous branches to represent the short‐ and long‐term time‐dependent stress responses to deformation, and a quasi‐static branch to represent the time‐independent stress response. A fast numerical analysis framework based on genetic algorithms was developed to determine values for the model parameters so that the difference between the simulation and the experimental data could be less than 0.08 MPa. Using this approach, values of the model parameters were determined as functions of deformation and time so that the model can simulate the stress response at loading, relaxation, and recovery stages of the RR test. The simulation also generated 10 sets of model parameter values to examine their consistency. The study concludes that the three‐branch model can serve as a suitable tool for analyzing the mechanical properties of HDPE, and values for the model parameters can potentially be used to characterize the difference among PEs for their mechanical performance. Highlights: Developed computer programs to determine parameter values automatically.Explained the unusual stress drop during stress recovery after unloading.Evaluated the statistical range of the parameter values for the good fitting. [ABSTRACT FROM AUTHOR]

Polyethylene mulching film, which is widely utilized in arid and semi-arid agriculture, leaves residual pollution. A novel approach to addressing this issue is microbial degradation. To screen the strains that degrade polyethylene efficiently and clarify the effect of degrading strains on the turnover of soil organic carbon, a polyethylene-degrading fungus PF2, identified as Trichoderma asperellum, was isolated from long-time polyethylene-covered soil. Strain PF2 induced surface damage and ether bonds, ketone groups and other active functional groups in polyethylene, with 4.15% weight loss after 30 days, where laccase plays a key role in the degradation of polyethylene. When applied to soil, the Trichoderma-to-soil weight ratios were the following: B1: 1:100; B2: 1:200; B3: 1:300 and B4: 1:400. Trichoderma asperellum significantly increased the cumulative CO2 mineralization and soil organic carbon mineralization in the B1 and B2 treatments compared with the control (B0). The treatments B1, B3 and B4 increased the stable organic carbon content in soil. An increase in the soil organic carbon content was observed with the application of Trichoderma asperellum, ranging from 27.87% to 58.38%. A positive correlation between CO2 emissions and soil organic carbon was observed, with the soil carbon pool management index (CPMI) being most correlated with active organic carbon. Trichoderma treatments improved the CPMI, with B3 showing the most favorable carbon retention value. Thus, Trichoderma asperellum not only degrades polyethylene but also contributes to carbon sequestration and soil fertility when applied appropriately. [ABSTRACT FROM AUTHOR]

Selective laser sintering (SLS) is gaining increasing importance in polymer additive manufacturing. It has many unique advantages compared with extrusion or photopolymerization based technologies. However, one of the main challenges for SLS is the limited types of compatible polymer microparticles. This study develops a versatile material platform for the scalable synthesis of polyethylene (PE) and its composite microparticles for SLS 3D printing. The incorporation of metal oxide nanoparticles inside PE microparticles by in situ sol‐gel chemistry as well as blending with carbon black for enhanced laser absorption is found to have significant impacts on the printability and physical properties of printed structures. Importantly, this study also demonstrates that post‐printing processing can substantially enhance the mechanical properties and introduce new functionalities to 3D PE structures. Thermal annealing improves the mechanical strength and modulus by more than ten times. Electrochemical deposition of copper on the 3D PE composite structures significantly enhances the electrical conductivity and mechanical properties, which can be utilized to fabricate 3D hierarchical metallic structures with broad applications. [ABSTRACT FROM AUTHOR]

Aiming at the problems in the high surface adhesion of ultrahigh-molecular-weight polyethylene (PE-UHMW) with viscous materials as well as its poor cleaning performance, the surface of PE-UHMW was modified with microstruc-ture by using a laser marking machine, and then its hydrophobicity was characterized by using a contact angle tester. The results indicated that the surface modification increased the hydrophobicity of PE-UHMW by 50 %, resulting in its anti-adhesion performance with a self-cleaning ability. The hydrophobicity of PE-UHMW was investigated through forming different types of microstructures on the modified surface, and the results showed that the bionic hogweed texture-modified surface had the best hydrophobicity. Based on this rule, the optimal processing parameters of the microstructural hydrophobicity could be achieved by an optimized combination of processing parameters for the hydrophobicity of the hogweed bionic microstructure. This combination was determined to be a fabric size of 400 |im, a transverse spacing of 100 μm, and a vertical spacing of 100 μm. Through varying the size of the texture, a relationship between the hydrophobicity of the texture and area ratio could be derived. The hydrophobicity increased and then decreased with an increase in the texture area ratio, and the maximum was achieved at a weaving area ratio of approximately 18. 5 %. [ABSTRACT FROM AUTHOR]

Polyethylene (PE) is the most commonly used plastic type in the world, contributing significantly to the plastic waste crisis. Microbial degradation of PE in natural environments is unlikely due to its inert saturated carbon‐carbon backbones, which are difficult to break down by enzymes, challenging the development of a biocatalytic recycling method for PE waste. Here, we demonstrated the depolymerization of low‐molecular‐weight (LMW) PE using an enzyme cascade that included a catalase‐peroxidase, an alcohol dehydrogenase, a Baeyer Villiger monooxygenase, and a lipase after the polymer was chemically pretreated with m‐chloroperoxybenzoic acid (mCPBA) and ultrasonication. In a preparative experiment with gram‐scale pretreated polymers, GC‐MS and weight loss determinations confirmed ~27 % polymer conversion including the formation of medium‐size functionalized molecules such as ω‐hydroxycarboxylic acids and α,ω‐carboxylic acids. Additional analyses of LMWPE‐nanoparticles using AFM showed that enzymatic depolymerization reduced the sizes of these mCPBA‐ and enzyme‐treated LMWPE‐nanoparticles. This multi‐enzyme catalytic concept with distinct chemical steps represents a unique starting point for future development of bio‐based recycling methods for polyolefin waste. [ABSTRACT FROM AUTHOR]

Developing plastics that fill the need of polyolefins yet are more easily recyclable is a critical need to address the plastic waste crisis. However, most efforts in this vein have focused on high‐density polyethylene (PE), while many different types of PE exist. To create broadly sustainable PE with modular properties, we present the synthesis, characterization, and demonstration of materials applications for chemically recyclable PE‐like multiblock polymers prepared from distinct hard and soft blocks using ruthenium‐catalyzed dehydrogenative polymerization. By altering the branching pattern within the soft blocks, a series of PE‐like multiblock polymers were synthesized with tunable glass transition temperatures (Tg) while maintaining consistent high melting temperatures (Tm). A clear U‐shape trend between Tg and mechanical properties was found, showcasing their potential as sustainable materials with tailored properties spanning commercial linear low‐density polyethylene (LLDPE) and low‐density polyethylene (LDPE). These materials offer adjustable adhesive strength to metal and demonstrate chemical recyclability and selective depolymerization in mixed plastic streams, promoting circularity and separation. [ABSTRACT FROM AUTHOR]

Introduction: Orthodontic clear aligners and retainers have numerous advantages that is making them ever increasingly popular. However, they might, similar to any other oral appliance, contribute to biofilm formation and finally dental caries or white spot lesions or gingival inflammations. The literature on biofilm formation on orthodontic clear appliances is very scarce and limited to a few microorganisms and materials. Therefore, this experimental study evaluated the biofilm formation on 5 thermoformed and 3D printed CAD/CAM orthodontic retainers in 3 intervals. Methods: In this in vitro study, 345 specimens (270 test discs and 45 negative controls) were created from fabricated retainers. Retainers included a 3D printed CAD/CAM material (Detax) and four thermoformed retainers [Erkodent (polyethylene terephthalate glycol [PETG]); EasyVac (polyethylene); DB (polyester based on terephthalic acid); and Clear Tech]. They were all 1 mm thick, and all completely fabricated, i.e., heated or printed. The discs were placed in 96-well plates. Microorganisms were cultured on 270 discs for 24 h (90 discs), 72 h (90 other discs), and 5 days or 120 h (90 other discs). Biofilm formation of the strains and negative controls was measured using the microtiter plate assay by ELISA reading. The microbes' ability to produce biofilm was categorized based on the comparison of average optical density (OD) of tests versus a cut-off point OD (ODc) calculated as the average of the OD of corresponding negative controls plus 3× its standard deviation: non-biofilm former [OD ≤ ODc], weak biofilm former [ODc < OD ≤ (2 × ODc)], moderate biofilm former [(2 × ODc) < OD ≤ (4 × ODc)], and strong biofilm former [(4 × ODc) < OD]. These were also converted to ranked scores between zero (no biofilm) and 3. The difference between ODs with control ODs were calculated. These were analyzed using 3-way ANOVA, 2-way ANOVA, and Tukey tests (α = 0.05, α = 0.008). Results: The 3-way ANOVA showed that the overall difference among the ΔODs of 5 retainers (all microorganisms and all intervals combined, n = 270) was not significant (F = 1.860, P = 0.119). Nevertheless, the difference among 3 intervals (F = 31.607, P = 0.0000) and the difference among the 6 microorganisms (F = 24.044, P = 0.0000) were significant. According to the Tukey test, the differences between the 1st interval with either of the other two intervals was significant (both P values = 0.000). There were significant differences between Candida albicans with all other organisms (all 5 P values = 0.0000). All other pairwise comparisons were insignificant (all 10 P values ≥ 0.1). After taking the averages of the 3 intervals, the order of the biofilm generation for different materials were as follows: Detax (average score: 1.56), Easyvac (1.67), Erkodent (1.78), Clear Tech (1.83), BD (2.28). Conclusions: As far as these 6 microorganisms are of concern, there might not be a significant overall difference among the clear retainer materials tested in this study. A significant overall increase was observed between the first and third days, which later did not significantly increase more until day 5. The Candida albicans biofilm was more intense than the tested 5 bacteria, which themselves showed rather similar growth patterns to each other. [ABSTRACT FROM AUTHOR]

Heptene‐graphitic nanoplatelets (HtGNP) serve as a filler for high density polyethylene (HDPE), generated through a mechanochemical reaction involving graphite and 1‐heptene. Various analyses indicate the efficient exfoliation of graphite into HtGNP, characterized by exceptional traits. Consequently, HtGNP & HDPE_5 nanocomposites, produced via the solution process, exhibit significantly increased tensile strength and Young's modulus, boasting corresponding increases of 27.7% and 13.7% compared to pure HDPE. Thus, owing to their outstanding performance, HtGNP emerges as a promising option in the form of a novel reinforcing additive for various hydrocarbon polymers. [ABSTRACT FROM AUTHOR]

Microwave‐assisted pyrolysis of PE to hydrogen and carbon material has great potential to solve the problem of waste PE induced white pollution and provide a promising way to produce hydrogen energy. To increase the hydrogen yield, a new microwave‐assisted pyrolysis procedure should be developed. In the present study, a facile double‐layer microwave‐assisted pyrolysis (DLMP) method is developed to pyrolyze PE. Within this method, PE can be converted to hydrogen, multiwalled carbon nanotubes with extremely high efficiency compared with the traditional methods. A high hydrogen yield of 66.4 mmol g−1PE is achieved, which is ≈93% of the upper limit of the theoretical hydrogen yield generated from the PE pyrolysis process. The mechanism of high hydrogen yield during the microwave‐assisted pyrolysis of PE using the DLMP method is also clarified in detail. The DLMP method paved the potential way for recycling plastic waste into high‐value‐added products. [ABSTRACT FROM AUTHOR]

Micro/nanoplastics (MNPs), which are widely spread in the environment, have gained attention because of their ability to enter the human body mainly through ingestion, inhalation, and skin contact, thus representing a serious health threat. Several studies have reported the presence of MNPs in lung tissue and the potential role of MNP inhalation in triggering lung fibrosis and tumorigenesis. However, there is a paucity of knowledge regarding the cellular response to MNPs composed of polyethylene (PE), one of the most common plastic pollutants in the biosphere. In this study, we investigated the effects of low/high concentrations of PE MNPs on respiratory epithelial cell viability and migration/invasion abilities, using MTT, scratch, and transwell assays. Morphological and molecular changes were assessed via immunofluorescence, Western blot, and qRT-PCR. We demonstrated that acute exposure to PE MNPs does not induce cellular toxicity. Instead, cells displayed visible morphological changes also involving actin cytoskeleton reorganization. Our data underlined the role of epithelial–mesenchymal transition (EMT) in triggering this process. Moreover, a remarkable increase in migration potential was noticed, in absence of a significant alteration of the cell's invasive capacity. The present study highlights the potential impact of PE MNPs inhalation on the human respiratory epithelium, suggesting a possible role in carcinogenesis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Valorizing XLPE plastic residue through catalytic flash pyrolysis. • Precise profiling: Py–GC/MS setup dissects volatile reaction products at 500 °C. • Kaolin catalyst: proven as a low-cost natural catalyst for flash pyrolysis. • Catalyst impact: kaolin shifts hydrocarbon concentration favorably. • Plastic waste yields gasoline-range hydrocarbons from catalytic flash pyrolysis. This investigation's novelty and objective reside in exploring catalytic flash pyrolysis of cross-linked polyethylene (XLPE) plastic residue in the presence of kaolin, with the perspective of achieving sustainable production of gasoline-range hydrocarbons. Through proximate analysis, thermogravimetric analysis, and heating value determination, this study also assessed the energy-related characteristics of cross-linked polyethylene plastic residue, revealing its potential as an energy source (44.58 MJ kg−1) and suitable raw material for pyrolysis due to its low ash content and high volatile matter content. To understand the performance as a low-cost catalyst in the flash pyrolysis of cross-linked polyethylene plastic residue, natural kaolin was subjected to characterization through thermogravimetric analysis, X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray fluorescence (XRF). Cross-linked polyethylene plastic residue was subjected to thermal and catalytic pyrolysis in an analytical microreactor coupled to gas chromatography-mass spectrometry (Py–GC/MS system), operating at 500 °C, to characterize the distribution and composition of volatile reaction products. The application of kaolin as a catalyst resulted in a decline of the relative concentration of hydrocarbons in the diesel range (C 8 -C 24) from approximately 87 % to 28 %, and a reduction in lubricating oils (C 14 -C 50) from about 70 % to 13 %, while concomitantly increasing the relative concentration of lighter hydrocarbons in the gasoline range (C 8 -C 12) from around 28 % to 87 %. Therefore, catalytic flash pyrolysis offers the potential for converting this plastic waste into a new and abundant chemical source of gasoline-range hydrocarbons. This process can be deemed viable and sustainable for managing and valorizing cross-linked polyethylene plastic residue. [ABSTRACT FROM AUTHOR]

The water absorption characteristics of thermoplastic starch (TPS) reveal its ability to interact with and absorb water, influencing its overall performance in various applications. The introduction of aloe vera (AV) gel into the TPS polymeric matrix film has proven beneficial in enhancing tensile strength but a notable deficiency is observed in lowering water absorption percentage. Therefore, this paper aims to reduce the water absorption of the TPS30AV polymer matrix film by utilizing polyethylene (PE) without reducing the tensile strength performance of the TPS30AV film. The TPS30AV film was produced using melt-blending and hot-press techniques. Six samples were presented consisting of a control film (TPS30AV) and TPS30AV film with different concentrations of PE resins (5%, 10%, 20%, 30%, and 40%). The film's performance was assessed by examining its mechanical properties, water absorption, and water solubility. The finding shows that TPS30AV with 40% PE has the highest improvement in water absorption percentage which reduces from 309.86% to 34.16% but a tremendous decrement in tensile strength performance. However, TPS30AV with 10% PE has the highest tensile strength, 9.65 MPa with a 20.99% improvement in water absorption reduction. The properties obtained for TPS30AV10PE were also good in Young's modulus and water solubility percentage. It shows that the film formulated is comparable with previous studies, and improvement has been achieved. As a conclusion, adding PE improved the polymeric structure of TPS30AV and can be used as a biodegradable food-packaging film. [ABSTRACT FROM AUTHOR]

The present Bayesian network meta-analysis compared different types of polyethylene liners in total hip arthroplasty (THA) in terms of wear penetration (mm/year) and rate of revision. The type of liners compared were the crosslinked ultra-high molecular weight polyethylene (CPE/UHMWPE), Vitamin E infused highly cross-linked polyethylene (HXLPE-VEPE), modified cross-linked polyethylene (MXLPE), highly cross-linked polyethylene (HXLPE), Cross-linked polyethylene (XLPE). This study was conducted according to the PRISMA extension statement for reporting systematic reviews incorporating network meta-analyses of healthcare interventions. In June 2024, PubMed, Scopus, Embase, Google Scholar, and Cochrane databases were accessed. A time constraint was set from January 2000. All investigations which compared two or more types of polyethylene liners for THA were accessed. Only studies that clearly stated the nature of the liner were included. Data from 60 studies (37,352 THAs) were collected. 56% of patients were women. The mean age of patients was 60.0 ± 6.6 years, the mean BMI was 27.5 ± 2.0 kg/m2. The mean length of follow-up was 81.6 ± 44.4 months. Comparability was found at baseline between groups. XLPE and HXLPE liners in THA are associated with the lowest wear penetration (mm/year) and the lowest revision rate at approximately 7 years of follow-up. [ABSTRACT FROM AUTHOR]

Reduced graphene oxide (rGO) was prepared from waste plastic using the two steps pyrolysis method and subsequently functionalized with ethylene diamine (EDA) to develop amino‐functionalized rGO (EDA‐rGO). To make the thermal and mechanical properties more proficient, EDA‐rGO was further incorporated as a nanofiller into a low‐density polyethylene (LDPE) matrix using the melt mixing method followed by hot‐pressing. A variety of analytical methods, such as FT‐IR, XRD, XPS, DSC, TGA, DMA, Raman spectroscopy, and HRTEM, were used to characterize the elements and morphology of rGO and EDA‐rGO. The results showed that the addition of 5 wt% EDA‐rGO to LDPE polymers significantly improved the mechanical and thermal properties, such as storage modulus by 62%, loss modulus by 67%, young's modulus by 123%, tensile strength by 79.83%, respectively. The thermal decomposition temperatures of 5%, 10% and 50% were increased by 14.01, 9.34, and 4.8°C, respectively. This study provides a feasible and ecologically sustainable way of repurposing plastic waste concurrently enhancing the properties of polymer composites. Highlights: Synthesis & functionalization of rGO from waste plastic using EDA.EDA‐rGO used as a nanofiller to fabricate LDPE polymer nanocomposites.EDA‐rGO enhanced the thermal stability of LDPE nanocomposites.The tensile strength & modulus of the LDPE composites are greatly improved.The storage, loss modulus, Tm and Tc enhanced by 62%, 67%, 4.4°C & 2.6°C. [ABSTRACT FROM AUTHOR]

We herein report the enhancement of thermal, electrical, electromagnetic interference (EMI) shielding, and mechanical performance of polyethylene (PE) nanocomposites by the introduction of non‐covalently modified multi‐walled carbon nanotube (MWCNT) and ethylene‐glycidyl methacrylate (EGMA) copolymer. For this purpose, benzylacetic acid‐functionalized MWCNT (BA‐M) is prepared by ball milling, and it is melt‐mixed with EGMA to prepare a masterbatch. The masterbatch is then melt‐compounded with neat PE to manufacture a series of PE/EGMA/BA‐M nanocomposites with 0.5–5 wt% MWCNTs. Electron microscopic and spectroscopic analyses confirm the successful fabrication of non‐covalently functionalized BA‐M, the uniform dispersity of MWCNTs in the PE matrix, and the chemical reactions between the carboxylic acid groups of BA‐M and the epoxy group of EGMA in the nanocomposites. Scanning calorimetric data reveals that BA‐M acts as an efficient nucleating agent for the crystallization of PE. The excellent dispersity and robust interfacial bonding of BA‐M in the PE matrix result in improved electrical and EMI shielding properties in PE/EGMA/BA‐M nanocomposites. Furthermore, the tensile strength, initial modulus, and impact strength of the nanocomposites gradually rise as the BA‐M content increases. Thus, the PE/EGMA/BA‐M nanocomposite containing 5 wt% MWCNT achieves excellent performance of EMI shielding effectiveness of ~14.7 dB/mm, tensile strength of ~34.5 MPa, initial modulus of ~295.7 MPa, and impact strength of ~539.9 J/m, which represent enhancements of ~265%, ~40%, ~82%, and ~452%, respectively, compared to pristine PE. Highlights: Non‐covalently modified MWCNT (BA‐M) was prepared by facile ball milling.PE nanocomposites with BA‐M and EGMA were prepared by masterbatch melt‐mixing.Excellent dispersity and interfacial bonding of MWCNT in the PE matrix were attained.Tensile strength and initial modulus of the nanocomposites were highly improved.EMI shielding effectiveness of the nanocomposite with 5 wt% MWCNT was ~14.7 dB/mm. [ABSTRACT FROM AUTHOR]

The two‐dimensional (2D) inorganic fillers could significantly improve the properties of polyolefin, thereby satisfying a wider range of applications. Herein, in this research, high‐performance polyethylene (PE)/siloxene nanocomposites were prepared through an in‐situ polymerization with layered siloxene‐supported Ti‐based catalyst. The catalytic ethylene polymerization activity of the siloxene‐supported Ziegler‐Natta catalyst was almost twice that of the MgCl2/TiCl4 catalyst when equal weights of catalysts were used. During the in‐situ polymerization, the layered siloxene fillers exhibited uniform dispersion within the PE matrix. The incorporation of a minimal amount of siloxene filler resulted in a notable enhancement in the thermal stability and mechanical properties of PE. The breaking strength, modulus, elongation at break, and Td5% of PE/siloxene nanocomposites with only 0.71 wt% siloxene were increased by 115.7%, 45.6%, 50.6%, and 58.2°C, respectively. Therefore, this research presents a straightforward method for manufacturing PE with outstanding performance. Highlights: PE/siloxene nanocomposites were prepared through in‐situ polymerization.Siloxene is uniformly scattered in the PE matrix.The siloxene and matrix exhibit excellent interfacial adhesion.PE/siloxene nanocomposites with excellent properties were obtained. [ABSTRACT FROM AUTHOR]

Microplastic studies investigating concentrations in water are numerous, but the majority of microplastics settle and are retained in sediment, and higher concentrations are regularly reported in sediments. Thus, MPs accumulation may be more threatening to benthic fish living in sediments than to pelagic fish. The presence, abundance and diversity of microplastics were investigated by collecting samples from two pelagic, European anchovy, and horse mackerel and two benthic fish species, red mullet, and whiting that are popularly consumed in Giresun province of Türkiye, located on the southern coast of the Black Sea. Visual classification and chemical compositions of microplastics was performed using a light microscope and ATR-FTIR spectrophotometry, consecutively. The overall incidence and mean microplastics abundance in sampled fishes were 17 and 1.7 ± 0.18 MP fish−1, respectively. MPs were within the range of 0.026–5 mm in size. In most of the cases, the MP was black in color with 41%. With the rates of 56%, polypropylene was the predominant polymer type. The most dominant MP type was identified as fiber followed by fragments and pellets. The relationship between MP amounts in fish and Fulton condition factor was not strong enough to establish a cause-effect relationship. [ABSTRACT FROM AUTHOR]

In order to suppress the damage of cable insulation caused by water tree structure formed by micro‐droplets at insulation defects in low density polyethylene (LDPE) materials under AC electric field. In this paper, the siloxane group is grafted onto LDPE by melt grafting method, and different content of comonomer styrene (St) is added to improve the grafting rate of siloxane group grafted polyethylene. The effect of St on the microscopic characteristics of LDPE grafted KH570 is studied. In order to verify the accuracy and timeliness of water tree self‐healing of grafted polymer insulation materials, the microstructure characteristics of LDPE ungrafted and grafted polymer samples are analyzed by Fourier transform infrared spectroscopy, gel content test, and differential scanning calorimeter. Second, the AC dielectric properties of LDPE ungrafted and grafted polymer samples are studied by AC breakdown experiment and space charge test. Finally, the water tree length, micropore defects, and self‐healing of the samples are observed by optical microscopy and polarization and depolarization current method, and the changes of chemical composition in the water tree area before and after aging are analyzed by infrared spectroscopy. The principle and mechanism of repairing water tree defects with grafted monomers are explained. This paper not only combines the previous research results of self‐healing materials, but also provides a new method for the preparation process of LDPE grafted polymer, which has a good research prospect in practical application. [ABSTRACT FROM AUTHOR]

Polyethylene‐supported nanofiltration (NF) membranes have been reported for several cases in recent years. However, few have disclosed a NF membrane which achieves a high salt/water separation efficiency. Here, a novel polyamide NF membrane was prepared by conducting interfacial polymerization on poly(vinyl alcohol)‐decorated polyethylene separator. The polyethylene‐supported NF membranes were systematically investigated with respect to chemical structures, microscopic morphology, surface properties, as well as desalination performance. In particular, a distinctive morphology transformation occurred on the polyamide layers through regulating poly(vinyl alcohol) loading amounts. Performance testings demonstrated the optimal membrane reaches a water permeance over 17.4 L·m−2·h−1·bar−1 and Na2SO4 rejection above 98.7%, as well as favorable performance stability. This work may provide some consideration for fabricating NF membranes with new support layers and good desalination performance. [ABSTRACT FROM AUTHOR]

Equilibrium passive sampling continues to find increasing use for performing in situ assessments and monitoring of hydrophobic organic compounds (HOCs). Although this method has been successfully used in several field studies including open surface waters and sediments, comparatively, their use in groundwater has been very limited. In this study, low-density polyethylene (LDPE) passive samplers were deployed for 80 days in three groundwater wells contaminated with polycyclic aromatic hydrocarbons (PAHs). Prior to deployment, LDPE was loaded with performance reference compounds (PRCs) consisting of deuterated PAHs and their release used to ascertain system equilibrium. Within the 80-day deployment period, LDPE-groundwater equilibrium was confirmed for PAHs with molecular weights (MWs) in the range of 178 to 228 (i.e. anthracene, chrysene). Measured freely dissolved concentrations (Cw) were between one to three orders of magnitude lower than the total filtered concentrations (Ctotal) in the studied wells. The sum of PAHs (ΣPAHs) measured based on Cw and Ctotal were 2.05, 0.07 and 29.2 μg L−1 and 197, 59.7 and 1010 μg L−1, at wells 1, 2 and 3, respectively. A separate dataset, comprising long-term (2010 to 2022) concentrations of PAHs in total (i.e., unfiltered) groundwater, is also presented to provide insight into PAH contamination levels at the assessed groundwater wells based on conventional measurement. Estimated in situ LDPE daily clearance volumes (2.34 to 27.56 Ld−1) for the target analytes were far less than the daily turnover of ground water (144 to 348 Ld−1) encountered in the wells eliminating the possibility of depletive sampling of the groundwater by the passive samplers. These results represent the first published study on the practical application of equilibrium passive sampling using LDPE for monitoring and quantitatively assessing PAHs in groundwater. Also, this work demonstrates that LDPEs are a useful tool for measuring the Cw of PAHs in groundwater, a critical contaminant in many ecological and human health risk assessments. [ABSTRACT FROM AUTHOR]

This paper explores methods to improve the sustainability of packing artworks, focusing on soft wrapping of framed paintings. In 2022, the UK Museums and Heritage Sustainable Packing Group was formed. The research described in this paper focuses on one aspect of the group's activity: seeking to find materials and methods which reduce environmental burdens and comply with conservation standards for soft wrapping two-dimensional artworks for short journeys between display, storage locations and conservators' studios. The project investigated the physical qualities of recycled content polyethylene (PE), bioplastics and paper-based alternatives, along with common barrier materials such as virgin PE sheet and Bubble Wrap®, to form comparative datasets. Each material's environmental impact, potential for reuse, interaction with artworks and ability to maintain adequate buffering against environmental changes during transport was researched. Alternative methods were also explored to reduce the quantity of sealing tape and promote its reversibility and reuse. The environmental impacts of the materials were assessed by sustainability specialists at the University of Manchester's Sustainable Materials Innovation Hub. Reusable and recycled content films offered the most promising alternatives to the PE wrapping most used at present. The use of a tying method, eliminating the need for adhesive tape, also showed potential for further investigation. The low-cost testing methodology should be refined to better control the variables and allow for more repeatable testing, but these preliminary results will help to refine future research directions. [ABSTRACT FROM AUTHOR]

Corneal abrasion is a frequent complication in critically ill, intubated patients, potentially leading to visual impairment. This study compares the efficacy of three ocular care methods in preventing corneal abrasion among this vulnerable population. We conducted a randomized controlled trial involving 156 intubated adult patients admitted to the ICU. Participants were randomly allocated to one of three intervention groups (n = 52 per group): (1) polyethylene cover only, (2) polyethylene cover with artificial tear drops, and (3) polyethylene cover with Lubratex eye ointment. One eye per patient was randomly assigned as the control, receiving standard ICU eye care. Daily assessments over five days included a standardized dryness and corneal abrasion checklist, graded strip evaluation of eye dryness, and documentation of corneal abrasion incidence. Data were analyzed using descriptive and inferential statistics (SPSS-18). The incidence of corneal abrasion was significantly lower in the group receiving polyethylene cover with Lubratex eye ointment (4%) compared to the polyethylene cover with artificial tears group (36%, p < 0.001) and the polyethylene cover only group (60%, p < 0.001). The combined application of a polyethylene cover with Lubratex eye ointment effectively prevents corneal abrasion in intubated ICU patients. This method demonstrates superior efficacy compared to polyethylene covers used alone or with artificial tears. We recommend its implementation as standard practice for corneal abrasion prophylaxis in this high-risk population. Trial Registration. This study is registered with the Iranian Registry of Clinical Trials (IRCT201506294736N8) and can be accessed at www.IRCT.ir. [ABSTRACT FROM AUTHOR]

Highly cross-linked polyethylene (HXLPE) was introduced to improve wear in total hip arthroplasty, with manufacturers implementing different thermal treatments to reduce oxidation. It is important to understand how long-term time in vivo affects the wear of these materials. The purpose of this study was to investigate the wear and oxidative performance of first-generation HXLPE hip inserts implanted for greater than 10 years and compare annealed and remelted HXLPE formulations. There were 49 total hip arthroplasty liners retrieved during routine revision surgery as part of an institutional review board–approved implant retrieval program. Penetration rates for the liners were calculated as the difference between the thickness of the unloaded and loaded regions divided by implantation time. Oxidation indices for the rim, locking mechanism, articulating surface, and backside regions were measured using Fourier-transform infrared spectroscopy according to American Society for Testing and Materials 2102. Mann–Whitney U tests were used to determine the statistical difference between annealed and remelted components. The cohort had an average implantation time of 13.1 ± 2.6 years for annealed and 12.1 ± 1.7 years for remelted components. The components were revised most often for polyethylene wear, instability, and loosening. The penetration rate averaged 0.0177 ± 0.014 mm/year for annealed components and 0.015 ± 0.022 mm/year for remelted components. Penetration rates did not differ between the remelted and annealed cohorts (P =.28). Oxidation indices were found to be significantly higher in the annealed cohort for all regions of interest (P <.001). Oxidation was found to be higher in the annealed HXLPE; however, this does not seem to be associated with greater wear as we found the average penetration rates for the cohorts were low, and the penetration rates were similar between the annealed and remelted cohorts. [ABSTRACT FROM AUTHOR]

A passive daytime radiative cooling thin film material has been developed to provide the cooling source which requires no input, sustainable, and no pollutants or greenhouse gases emission. The thermally induced phase separation method and simple compression were used to prepare the compressed composite silica dioxide/polyethylene(SiO2/PE) aerogel films. The impact of SiO2 particle sizes and additions on the optical properties of composite films was investigated, and the internal microstructures and optical properties of the films were characterized. The optical properties of the films were enhanced by controlling the degree of compression. The results indicate that the addition of micro SiO2 is more favorable for increasing reflectance and nano SiO2 is more favorable for increasing emissivity, and the densification could result in emissivity enhancement and reflectance reduction. The optimal sample is achieved when the mass ratio of nano SiO2 to micro SiO2 to polyethylene is 0.5∶1∶1 and the compression ratio is one-ninth. This sample has a thickness of 0.5 mm, with 96.4% average reflectance of the solar spectrum and 95% average emissivity of the atmospheric window. The practical application performance of the sample was evaluated by testing its radiative cooling performance, antifouling and mechanical stability abilities. The experimental results show that the optimal sample achieves a significant temperature reduction of up to 6.5 ℃ compared to the sub-environment. This indicates that the SiO2/PE aerogel film has the ability to passively cool the sub-environment during both day and night, and that it has a contact angle with water of 127°, providing water resistance and potential self-cleaning properties in practical applications. [ABSTRACT FROM AUTHOR]

This study analyzed the total phenolic content (TPC), antioxidant, and antimicrobial activity of traditionally produced Malatya cheeses made from cow's milk. Cheeses were ripened either in brine using plastic drums or in dry salted polyethylene bags at 7 and 20°C for 120 days. Results showed that cheeses ripened in polyethylene had higher TPC and antioxidant activity compared to those in plastic drums. The highest TPC and antioxidant activity were found in water-soluble extracts from the dry salted samples ripened at 20°C for 120 days, while the lowest were in cheeses ripened in brine at 7°C for just 2 days. The antimicrobial activity was tested against two bacteria using an agar well diffusion technique, but no antimicrobial effects were observed. Overall, the findings suggest that salting methods, ripening times, and temperatures significantly influence the TPC and antioxidant activity of Malatya cheeses. [ABSTRACT FROM AUTHOR]

Unraveling the deformation processes of semicrystalline polymers is essential for improving their durability. Owing to their hierarchical structures composed of lamellae and spherulites, many aspects of these deformation processes remain unclear at the molecular scale, such as the differences in molecular structure changes in the elastic and plastic regions and the molecular‐scale structural changes during reversible and irreversible processes. Herein, simulated creep tests of the lamellar structure of polyethylene under a constant load are performed using the coarse‐grained molecular dynamics method. Typical creep curves are observed under various constant loads. During the recovery process after stretching, the reversible and irreversible processes are distinguished by a strain of approximately 0.4 at the boundary of the elastic and plastic regions. Interestingly, during recovery, the interfaces between the amorphous and crystalline layers are highly oriented, which may inhibit strain relaxation. In terms of the molecular structure changes in the plastic region, the number of tie chains remains constant, whereas the numbers of chain ends and loops in the amorphous layers decrease. These simulation results advance current understanding of the molecular‐scale deformation processes of semicrystalline polymers, which contribute to the improvement of long‐term durability and reliability. [ABSTRACT FROM AUTHOR]

Under varying flow rate conditions, the transport and retention of polydisperse microplastics (MPls), with an average particle size of 16 ± 6 µm, were investigated in saturated porous media. First-order reversible and irreversible kinetic sorption models were used to describe the sorption kinetics. Sensitivity analyses provided insight into the effects of each sorption parameter. Both numerical modeling and experimental measurements were utilized to evaluate the retention rates of sand filters. The influence of flow rate on sorption was reflected in variations in the distribution coefficient (Kd), the mass transfer coefficient (β), and the irreversible sorption rate (K1). Lower flow rates were associated with higher Kd and β values, indicating increased sorption and reduced mass transfer rates. An increase in Kd resulted in a more gradual sorption process, with a decrease in peak concentration, whereas changes in β had a comparatively smaller impact on sorption rate and peak concentration. Lower K1 values were linked to higher peak concentrations and decreased retention efficiency. Numerical modeling revealed retention rates of 28 ± 1% at a flow rate of 31 mL min−1 and 17 ± 1% at 65 mL min−1. The introduction of MPls into saturated sand environments modifies the transport dynamics within the medium. Consequently, these alterations affect the hydrological characteristics of porous media, impacting groundwater quality and agricultural output. The mean absolute error (MAE) of 6% between the modeled and observed retention rates indicated a high level of accuracy. This study underscores the importance of examining retention efficiency and the accuracy of numerical models in understanding MPl transport in porous media. [ABSTRACT FROM AUTHOR]

Simple Summary: This study investigates the biodegradation of polyethylene (PE) by Galleria mellonella larvae, exploring the impact of co-diet supplementation. Polyethylene, a prevalent plastic, poses significant environmental pollution due to its resistance to natural degradation. This research evaluates the larvae's efficiency in consuming PE of various densities with and without co-diets like beeswax and wheat germ + honey. The findings indicate that the larvae consumed more PE when the density was lower, with 1 mm thickness showing the highest consumption and minimal weight loss when beeswax was added. The larvae demonstrated higher biodegradation rates within 24 h compared to within 48 and 72 h. The co-diet supplementation, particularly with beeswax, enhanced PE consumption, aligning with the larvae's natural diet. This research underscores the potential of using G. mellonella larvae for the environmentally friendly biodegradation of PE, suggesting further exploration of the larvae's digestive mechanisms to develop sustainable solutions for plastic pollution. Pollution coming from plastic polymers, particularly polyethylene (PE), poses a serious threat to both humans and animals. The biodegradation of plastics facilitated by insects is a crucial and eco-friendly approach that can be employed to combat this global concern. Recently, the larvae of the greater wax moth Galleria mellonella (L.) have been recognized as avid 'plastivores'. The current study was aimed at evaluating the feeding efficiency of G. mellonella larvae on PEs of various densities with a co-diet supplementation of wheat germ + honey and beeswax. The results reveal that maximum PE consumption (9.98 ± 1.25 mg) was recorded in the case of 1.0 mm thick PE after a 24 h interval; however, the same scenario also achieved the greatest reduction in larval weight (27.79 ± 2.02 mg). A significant reduction in PE mass (5.87 ± 1.44 mg) was also observed in 1.0 mm PE when fed beeswax; however, the larvae experienced minimal weight loss (9.59 ± 3.81 mg). The larvae exhibited a higher PE consumption in 1.0 mm PE, indicating that the lower the density of PE, the greater the consumed area. Moreover, the biodegradation levels were notably higher within the 24 h interval. In conclusion, these findings suggest that the density of PEs and the supplementation of the co-diet have an impact on PE biodegradation. Additionally, the utilization of G. mellonella for the biodegradation of PE proves effective when combined with beeswax, resulting in minimal weight loss of the larvae. Our findings offer initial insights into how Galleria mellonella larvae biodegrade polyethylene (PE) of four different densities, along with co-diet supplementation. This approach helps us evaluate how varying densities affect degradation rates and provides a better understanding of the larvae's capabilities. Additionally, our observations at three specific time intervals (24, 48, and 72 h) allow us to identify the time required for achieving degradation rates. Through examining these time points, our method offers valuable insights into the initial phases of plastic consumption and biodegradation. [ABSTRACT FROM AUTHOR]

Introduction: With the increasing demand for aesthetics, the popularity of Vacuum-formed Retainers (VFRs) has been on the rise. Bisphenol-A (BPA) is added to the polymers to make them clear and tough. BPA is identified as an endocrine disruptor linked to developmental defects, infertility, cardiovascular disease and cancer. The release of BPA from various orthodontic materials, including VFRs, has been reported infrequently and with variable results. Aim: To assess the effect of immersing VFRs in distilled water on BPA release in the saliva of patients wearing VFRs. Materials and Methods: This was a single-centre prospective randomised clinical trial. A total of 28 patients aged between 15 and 25 years, who had completed their fixed orthodontic treatment in 2021 at Bharati Vidyapeeth Deemed to be University (BVDU), Dental College and Hospital, Sangli, Maharashtra, India, were selected for this in-vivo study. Patients were randomly divided into two groups. Group I patients received VFRs without immersion in water before delivery, while Group II patients received VFRs that were immersed in distilled water at 37°C for 24 hours before delivery. Four samples of unstimulated whole saliva were collected across four different time intervals: T0 (before VFR delivery), T1 (after one hour of wearing retainers), T2 (after one week of wearing retainers) and T3 (after three weeks of wearing retainers). These samples were tested for BPA release using HPLC analysis. For numerical continuous data following a normal distribution, intergroup comparison was conducted using a one-way Analysis of Variance (ANOVA) test and intragroup comparisons were performed using a paired t-test. An alpha error of 5% and a power of 80% were maintained, with p<0.05 considered statistically significant. Results: The mean age of patients selected for the study was 20±5 years. Statistical analysis revealed that the mean release of BPA (0.33 ppm) in saliva was highest in patients from Group I at T1, decreasing to 0.177 ppm at T2 and further reducing to 0.013 ppm at T3. In comparison, the mean values of BPA release in the saliva of patients in Group II were significantly lower at all time intervals: T1 (0.07 ppm), T2 (0.009 ppm) and T3 (0.001 ppm). Intergroup comparison using a one-way ANOVA test showed that the difference in BPA release between the two groups was statistically significant (p-value=0.05). Tukey's posthoc test revealed statistically significant differences in BPA release between T1-T2, T2-T3 and T1-T3. Conclusion: Prior immersion of VFRs in distilled water for 24 hours at 37°C before delivery to patients can be a simple solution to reduce BPA release in saliva. [ABSTRACT FROM AUTHOR]

Understanding the molecular basis of rheological properties is crucial from both experimental and theoretical perspectives. Slit rheometry is commonly employed to measure the viscosity of fluids. This study utilized molecular dynamics simulations to investigate isothermal contraction flow at the nanoscale. Short linear polyethylene chains were uniformly extruded by a constant-speed piston from a reservoir through an abrupt contraction slit into the surrounding vacuum. Overall, die swelling and die wetting phenomena were observed. Molecular chains were stretched within the slit, while those outside the slit shrunk. Notably, the velocity profile within the slit varied with wall slip at different extrusion velocities. The relationship between the apparent shear viscosity and shear rate exhibited two primary characteristics: the first-Newtonian plateau and the shear thinning slope. Therefore, this molecular simulation method effectively demonstrates the general non-Newtonian behavior of macroscopic polymer fluids. [ABSTRACT FROM AUTHOR]

BACKGROUND: Uncemented acetabular components are widely used in modern total hip arthroplasty (THA). Modularity has numerous advantages including the ability to use supplementary screw fixation for the shell, and allow to switch from ceramic to polyethylene (PE) bearings and vice versa, and the use of lipped and face-changing liners. OBJECTIVE: Despite these advantages, a problem with modular PE liners is dissociation. This is a rare complication in modern implants. The rate of liner dissociation is reported to be very low between 0.17% and 0.8%. Typical symptoms are sudden onset of groin pain in a previously well-functioning hip joint, followed by grinding or clicking sensations during hip joint motions indicating, that the femoral head is articulating with the metal acetabular shell rather than with the PE liner. Any newly observed noise or squeaking from a THA should undergo radiographic investigation to exclude liner dissociation. CASE PRESENTATION: We present the case of an 88-yearold male patient who developed PE liner dissociation in a cementless THA with a Pinnacle acetabular component six years after the index operation. We recommended revision of the left hip, which was performed two days later. In the interim, the patient was advised to use a pair of crutches. During revision surgery, it was observed that the metal head made contact with the cementless cup shell without damaging it from a macroscopic standpoint. Consequently, a simple exchange of the PE liner was conducted, and a 36 mm metal head was implanted due to scratches on the original head. CONCLUSION: Early diagnosis facilitates a straightforward exchange of the liner along with the head, potentially preserving the osseous integrated cup shell and stem integrity. Routine radiologic follow-up allows to distinguish between PE liner dissociation and severe PE wear. [ABSTRACT FROM AUTHOR]

Late-season dehydration (LSDN) is a physiological disorder affecting grape berry water content, resulting in dehydration. Vineyards in the Aegean Region of western Türkiye have experienced problems with LSDN, particularly during periods of high temperatures. This research examines how partial canopy covering materials affect temperature differentials inside and outside the canopy, including the determination of LSDN grape berries of Sultan 7 (Vitis vinifera L.). A partial shading net (PS) was employed to prevent LSDN in the grape berries, and shading net and polyethylene material (PSP) were deployed to assess the impact of increasing canopy temperatures on the occurrence of LSDN in grape berries. Although partial covering materials did not substantially affect grapevine yield, the control group produced the largest and the heaviest berries. In the second year, warmer conditions led to more clusters with LSDN-affected berries and increased sunburn damage on clusters. PS showed a high healthy cluster rate of 72.50%, while PSP and control showed lower rates of 63.60% and 58.10%, respectively. Throughout the study period, PS exhibited 9.02% LSDN berries, while the control and PSP showed 17.10% and 16.70% clusters with LSDN berries in the total harvested clusters, respectively. The study showed that PS treatment alleviated LSDN symptoms in clusters. [ABSTRACT FROM AUTHOR]

The antibacterial activity of biomedical polymer materials is an important basis for their resistance to biofilm contamination as implantable medical devices. However, developing durable and stable antibacterial composites through a universal manufacturing method remains a challenge. Herein, based on an organic–inorganic synergistic antibacterial strategy, functional nanoparticles with high antibacterial performance and better polymer compatibility were prepared by combining zinc oxide nanoparticles (ZnO NPs) with quaternary ammonium compound 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride (QAS), which containing siloxane group. The ZnO-QAS nanoparticles were then introduced to low-density polyethylene (LDPE) by simple melt blending to manufacture synergistic antibacterial composites. The organic–inorganic hybrid strategy significantly improved the antibacterial activity of the composites, the PE/ZnO-QAS composites possess satisfactory antibacterial efficiency of 99.9% and 99.75% against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), respectively, and it could effectively inhibit biofilms. In addition, the functionalization of organic compound QAS provides excellent polymer compatibility for ZnO NPs, which is conducive to their uniform dispersion in LDPE, and comprehensively improves the thermal stability, mechanical properties, and crystallinity of the composites. This provides potential application value for the preparation of long-term stable antibacterial biomedical materials. [ABSTRACT FROM AUTHOR]

This study proposes an affordable plasma device that utilizes a parallel-plate dielectric barrier discharge geometry with a metallic mesh electrode, featuring a straightforward 3D-printed design. Powered by a high-voltage supply adapted from a cosmetic plasma device, it operates on atmospheric air, eliminating the need for gas flux. Surface modification of polyethylene treated with this device was characterized and showed that the elemental composition after 15 min of plasma treatment decreased the amount of C to ~80 at% due to the insertion of O (~15 at%). Tested against Candida albicans and Staphylococcus aureus, the device achieved a reduction of over 99% in microbial load with exposure times ranging from 1 to 10 min. Simultaneously, the Vero cell viability remained consistently high, namely between 91% and 96% across exposure times. These results highlight this device's potential for the surface modification of materials and various infection-related applications, boasting affordability and facilitating effective antimicrobial interventions. [ABSTRACT FROM AUTHOR]

The growing production and use of plastics significantly contribute to microplastics (MPs) contamination in the environment. Humans are exposed to MPs primarily through the gastrointestinal route, as these particles are present in beverages and food, e.g., sugar. Effective isolation and identification of MPs from food is essential for their elimination. This study aimed to evaluate factors influencing the isolation of MPs from sucrose solutions to determine optimal conditions for the process. Polyethylene particles were used to test separation methods involving chemical digestion with acids and filtration through membrane filters made of nylon, mixed cellulose ester, and cellulose acetate with pore sizes of 0.8 and 10 µm. The effects of temperature and acid type and its concentration on plastic particles were examined using scanning electron microscopy and µ-Raman spectroscopy. The results indicate that increased temperature reduces solution viscosity and sucrose adherence to MPs' particles, while higher acid concentrations accelerate sucrose hydrolysis. The optimal conditions for MPs' isolation were found to be 5% HCl at 70 °C for 5 min, followed by filtration using an efficient membrane system. These conditions ensure a high recovery and fast filtration without altering MPs' surface properties, providing a reliable basis for further analysis of MPs in food. [ABSTRACT FROM AUTHOR]

In this research, a new computational method was proposed for describing the mechanical behavior of super-elastic-plastic foams under inhomogeneous compressive impacts. The method regarded the foam material as composed of two typical mechanical properties superimposed multiple times: one was the hyper-elastic layer, and the other was the elastoplastic layer. The hyper-elastic layer and the elastoplastic layer were interwoven and overlapped, divided into double-layer, four-layer, and six-layer configurations to characterize the foam material. After the equivalent layering of the foam, by comparing the results of the four-layer and six-layer divisions, it was found that when the layering reached four layers, the foam performance curve had already converged. The study utilized the HYPERFOAM model and Mullins effect in the ABAQUS software to establish the constitutive relationship of the hyper-elastic layer. It adopted the Crushable foam model to develop the constitutive relationship of the elastoplastic layer. Under uniaxial compression conditions, quasi-static and intermediate strain rate compression tests were performed on polyethylene (PE) foam materials with three different densities. Based on the experimental results, the parameter values of the hyper-elastic-plastic foam model in the ABAQUS code were determined. By comparing the computational results and the experimental results, the established finite element (FE) model was validated using the mechanical behavior of indentation and compression tests. The results showed that this method could effectively describe the complex mechanical behavior and residual deformation of hyper-elastic-plastic foam packaging materials under non-uniform compression, and the experimental and simulation results agreed well, proving the reliability of this method. [ABSTRACT FROM AUTHOR]