Effect of benzoyl chloride treatment on morphological, thermal, mechanical, and hydrothermal aging properties of date palm/polyvinyl chloride (PVC) composites.

The use of natural fibers has seen a significant rise in the composites sector, resulting in the creation of polymer composites with exceptional strength. These environmentally-friendly alternatives offer a compelling substitute for synthetic composites. This study explores the use of date palm waste as reinforcement for the fabrication of polyvinyl chloride (PVC) composites. A surface modification method was essential for improving the binding interaction between palm fibers and PVC composites. The two-hour benzoyl chloride treatment at 140 °C played a crucial role. The study examined the effects of hydrothermal aging on mechanical properties of composites, using various techniques such as surface morphology analysis, Fourier Transform Infrared spectroscopy, and Thermogravimetric Analysis, on composites made of untreated fibers and those treated with benzoyl chloride. Although the treatment of palm fiber-reinforced composites with benzoyl chloride improved their mechanical properties, it is crucial to note that hydrothermal aging reduced their tensile strength by 10%. Despite this, these composites prove to be well-suited for applications requiring moderate strength and stiffness in mild environmental conditions. These composites, while utilizing benzoyl chloride for surface treatment, still represent a more sustainable alternative to traditional synthetic composites by incorporating renewable date palm waste and enhancing mechanical properties, which potentially reduces overall environmental impact.

Investigation of interaction mechanism between polyvinyl chloride microplastics and phthalate acid esters using APGC-MS/MS.

Phthalate acid esters (PAEs) are a kind of typical endocrine disruptors chemicals (EDCs). PAEs can be enriched, migrated and released into organisms through microplastics (MPs), causing high toxicological risks. This study presented an atmospheric pressure gas chromatography-tandem mass spectrometry (APGC-MS/MS) method for 10 PAEs trace analysis. Based on this method, the interaction mechanism between polyvinyl chloride microplastics (PVC MPs) and PAEs was explored. The established APGC-MS/MS method achieved 10 PAEs analysis in 14 min with the satisfied detection limit as low as 0.0025 µg/L and excellent linearity (R2 = 0.99868-0.99996). The interaction mechanism investigation showed that PVC MPs had high adsorption and desorption capacities for PAEs. The adsorption mechanism involves adsorption distribution, surface adsorption, hydrophobic interaction and intermolecular van der Waals force. Temperature, diffusion channels, pore filling, hydrophobicity and solubilization may be potential desorption mechanisms. Moreover, the intestinal environment of warm-blood organisms has the highest bioavailability of PAEs. Overall, this APGC-MS/MS method of PAEs had the virtue of simplicity, efficiency, reliability and sensitivity, and could serve as a potential tool for risk analysis of MPs and PAEs exposure.

Emissions of Semi-Volatile Organic Compounds from Architectural Coatings and Polyvinyl Chloride Floorings: Microchamber Method.

Semi-volatile organic compounds (SVOCs) are modern chemical substances that are present in large quantities in indoor environments. Understanding the emission of SVOCs from building materials is essential to identify the main sources of indoor SVOCs and to improve indoor air quality. In this study, a reference method employing custom-designed microchambers (630 mL) was optimized by improving the structure of the gas path and adding polytetrafluoroethylene inner coating to the chamber. After optimization, the recoveries of the microchamber method were significantly improved (75.4-96.7%), and the background in the microchamber was greatly reduced (<0.02 µg/h). By using the microchamber method, 33 SVOCs (including two alkanes, one aromatic, one nitrogen compound, and twenty-nine oxygenated compounds) and 32 SVOCs (including seven alkanes, eight aromatics, and seventeen oxygenated compounds) were detected in the emissions of the architectural coating and the PVC flooring samples, respectively. The area-specific emission rates (SERa) of total SVOCs emitted from architectural coatings and PVC floorings were in the range of 4.09-1309 µg/m2/h) (median: 10.3 µg/m2/h) and 0.508-345 µg/m2/h (median: 11.9 µg/m2/h), respectively. Propanoic acid had the highest SERa (3143 µg/m2/h) in architectural coatings, while methylbenzene (345 µg/m2/h), 2-methylnaphthalene (65.2 µg/m2/h), and naphthalene (60.3 µg/m2/h) were main SVOCs emitted from PVC floorings. Meanwhile, the average second-stage (adsorbed phase) emission mass of the total SVOCs accounts for 66.3% and 47.3% in architectural coatings and PVC floorings, respectively, suggesting that the SVOCs emitted from building materials have a strong tendency to be absorbed on the surface of the room, e.g., the interior wall, the desk or even the skin.

Polyvinyl chloride microplastics disseminate antibiotic resistance genes in Chinese soil: A metagenomic analysis.

The widespread prevalence of microplastics (MPs) in the environment poses concerns as they are vectors of antibiotic resistance genes (ARGs). The relationships between antibiotic resistomes and MPs remain unexplored in soil which was considered as the reservoirs of MPs and ARGs. This study investigated the effects of polyvinyl chloride (PVC) MPs on soil bacterial communities and ARG abundance which soil samples sourced from 20 provinces across China. We found that PVC significantly influences soil bacterial community structure and ARG abundance. Structural equation modeling revealed that PVC alters soil characteristics, ultimately affecting soil bacterial communities, including ARG-containing bacterial hosts, and the relative abundance of ARGs. This study enhances our understanding of how MPs influence the proliferation and hosts of ARGs within diverse soil environments, offering crucial insights for future strategies in plastic management and disposal.

Combined effects of polyvinyl chloride or polypropylene microplastics with cadmium on the intestine of zebrafish at environmentally relevant concentrations.

Cadmium (Cd) is a common additive in polyvinyl chloride (PVC) and polypropylene (PP) plastics. Aquatic organisms were inevitably co-exposed to PVC/PP microplastics (MPs) and Cd, but their combined toxicity is still unknown. In this study, adult zebrafish were exposed to 200 µg/L MPs (PVC or PP) and 10 µg/L Cd alone or in combination for 28 days to investigate their toxicity and mechanisms. Results showed that combined exposure with PVC/PP enhanced the Cd accumulation in the zebrafish intestine. Subsequently, toxicology analyses showed that both PVC and PP possessed synergistic toxicity with Cd, manifested by the exfoliation and necrosis of intestinal epithelial cells, and increased levels of interleukin-1ß (IL-1ß), superoxide dismutase (SOD) and malondialdehyde (MDA). PP exhibited a stronger synergistic effect than PVC. Integration of non-targeted metabolomics and 16S rRNA gene sequencing revealed that combined exposure to PVC and Cd induced intestine toxicity mainly through bile acid (BA) biosynthesis, fructose (Fru) and mannose (Man) metabolism, and pentose phosphate pathway (PPP). The combined exposure of PP and Cd induced toxicity through the arginine (Arg) and glutathione (GSH) metabolisms. Meanwhile, combined exposure of PVC/PP and Cd increased the abundance of intestinal Proteobacteria and pathogen Vibrio, and decreased the abundance of Gemmobacter. These changes indrectly promoted the synergistic toxicity of PVC/PP and Cd through metabolites, such as indole-3-pyruvate (IPyA), chenodeoxycholic acid (CDCA), and cholic acid (CA). These findings highlighted that more attention should be paid to the toxicity of chemicals at environmentally relevant concentrations, particularly those co-existing with MPs.

Comparative Analysis of the Color Stability of Machined Denture Base Materials: An In-Vitro Approach.

Background: Color stability is a crucial aspect in the selection of denture base materials as it directly impacts the esthetic appeal and longevity of dental prostheses. This study aimed to compare the color stability of different denture base materials through an in vitro approach. Materials and Methods: Three machined denture base materials including polymethyl methacrylate (PMMA), Acetal (AC), and polyether ether ketone (PEEK) were subjected to artificial aging using a xenon-arc lamp. Color measurements were taken before and after aging using a spectrophotometer. Statistical analysis was performed to determine any significant differences among the materials. Results: The color stability of the denture base materials was quantitatively assessed using parameters such as ΔE values. PEEK exhibited the least color change (ΔE = 2.1 ± 0.3), followed by AC (ΔE = 3.5 ± 0.4), while PMMA showed the highest color change (ΔE = 5.9 ± 0.7). Conclusion: In this in vitro study, PEEK demonstrated superior color stability compared to AC and PMMA denture base materials under artificial aging conditions. These findings emphasize the importance of material selection in achieving long-term esthetic outcomes in dental prostheses.

Effects of polyvinyl chloride and low-density polyethylene microplastics on oxidative stress and mitochondria function of earthworm (Eisenia fetida).

Plastics are widely used worldwide due to their convenience. However, microplastics (MPs) accumulation poses a serious threat to ecosystem health. Therefore, understanding the effects of MPs on living organisms within their native ecosystem is crucial. Previous studies have primarily focused on the impacts of MPs in aquatic environments, whereas the effects of MPs on terrestrial ecosystems have remained largely understudied. Therefore, our study assessed the impacts of MPs on soil ecosystems by characterizing their toxic effects on earthworms (Eisenia fetida). Here, we exposed earthworms to two representative plastics within soil environments: polyvinyl chloride (PVC) and low-density polyethylene (LDPE). Given the known link between MPs and oxidative stress, we next quantified oxidative stress markers and mitochondrial function to assess the effects of MPs on the redox metabolism of earthworms. Mitochondria are crucial metabolic organelles that generate reactive oxygen species via uncontrolled ATP production. Our findings demonstrated that MPs exert different effects depending on their type. Neither the PVC-exposed groups nor the LDPE-exposed groups exhibited changes in oxidative stress, as worked by the action of superoxide dismutase (SOD) and glutathione (GSH). While treatment of the two types of MP did not significantly affect the amount of reactive oxygen species/reactive nitrogen species (ROS/RNS) generated, PVC exhibited a more pronounced effect on antioxidant system compared to LDPE. However, mitochondrial function was markedly decreased in the group exposed to high LDPE concentrations, suggesting that the examined LDPE concentrations were too low to activate compensatory mechanisms. Collectively, our findings demonstrated that exposure of MPs not only influences the antioxidant defense mechanisms of earthworms but also alters their mitochondrial function depending on their types.

Ecotoxicological assessment, in freshwater environment, of wastewater sludge coupled and uncoupled with micro-polyvinyl chloride on algae and water fleas.

In the frame of bioeconomy and circular economy, wastewater sludge (WS) could be a good candidate for its use in agriculture as fertilizer, due to its high content of organic matter, N and P, but on the other hand, it is full of toxicants such as heavy metal, microplastics, detergent, antibiotics, and so on that can reach groundwater and water bodies in leachate form. In this study, we have investigated different sludge concentrations in the eluate form, combined and not with PVC on two different freshwater organisms Selenastrum capricornutum and Daphnia magna, using ecotoxicity tests. At the endpoint, we have evaluated inhibition growth rate, oxidative stress, and pigments production for S. capricornutum, while in case of D. magna, we have assessed organism immobilization and development. From our results, it emerged that at the higher WS concentration, there was not inhibition growth rate, while at oxidative stress, it was higher in algae treated with WS and PVC. Higher Chl-a production was shown for algae treated with 0.3 g/L of sludge coupled with PVC, where higher phaeopigments production were recorded for algae treated with 0.3 g/L of WS. D. magna has shown an opposite trend when compared with algae, where at the highest WS concentrations supplied was corresponding to an increased mortality explaned as the highest immobility percentage. PRACTITIONER POINTS: Wastewater sludge is used in agriculture as fertilizer. PVC microplastic presence and associate ecotoxicity was tested. PVC presence increased oxidative stress in S. capricornutum. D. magna was significantly affected by sludge concentrations supplied.

Electromechanical Performances of Polyvinyl Chloride Gels Using (Polyvinyl Chloride-Co-Vinyl Acetate) (P(VC-VA)) Synergistic Plasticization.

The current polyvinyl chloride (PVC) gel flexible actuators are facing challenges of high input voltage and an insufficient elastic modulus. In this study, we conducted a detailed study on the properties of PVC gel prepared by introducing the modifier polyvinyl chloride-vinyl acetate (P(VC-VA)). We compared a modified PVC gel with the traditional one in terms of the relative dielectric constant, mechanical modulus, and electromechanical actuation performance. Experimental results demonstrated that the introduction of P(VC-VA) enhanced the dielectric constant and reduced the driving electric field strength of PVC gels. The dielectric constant increased from 4.77 to 7.3. The electromechanical actuation performance increased by 150%. We employed the Gent model to fit the experimental results, and the actual experimental data aligned well with the expectations of the Gent model. The research results show that this type of plasticizing method effectively balanced the mechanical and electrical performance of PVC gels. This study summarizes the experimental results and performance analysis of PVC gels prepared using innovative plasticization methods, revealing the potential engineering applications of polymeric gels.

Are recyclable plastics eco-friendly? Recycled PVC microplastics show higher toxicity than pristine PVC on Vallisneria natans, regardless of Cadmium.

As environmental awareness increases, the use of recyclable plastics has risen. However, it is currently unclear whether recycled microplastics (MPs) pose a lesser or greater environmental risk than pristine MPs. Cadmium (Cd), known for its toxicity to most organisms, can bind with MPs and accumulate in sediments. Few studies have explored the environmental risks posed by the coexistence of recycled MPs and pristine MPs with Cd to rooted macrophytes. We investigated the effects of recycled PVC MPs (R-PVC-MPs) and pristine PVC MPs (PVC-MPs) on Vallisneria natans in the presence and absence of Cd. Results showed that at moderate and high Cd levels, R-PVC-MPs reduced plant Cd enrichment. Despite this, the fresh weight of V. natans exposed to R-PVC-MPs was significantly lower than those exposed to PVC-MPs. Furthermore, R-PVC-MPs had more negative impacts on the physiological traits of V. natans than PVC-MPs, as chlorophyll was significantly reduced across all Cd levels. At high Cd levels, both R-PVC-MPs and PVC-MPs caused significantly high oxidative stress, with no significant differences observed. The PCoA plot showed that different MPs cause noticeable variations within the same Cd concentration. The trait network diagrams illustrated strong interactions among traits, with R-PVC-MPs showing the highest complexity. Lower average degree and decreased edge density indicate that traits of plants with R-PVC-MPs addition are more independent of each other. Our findings suggest that recycled PVC MPs pose a greater environmental risk than pristine PVC MPs, offering reference for assessing the risks of recycled plastics in freshwater ecosystems.

Effects of polyvinyl chloride microplastics and benzylalkyldimethylethyl compounds on system performance, microbial community and resistance genes in sulfur autotrophic denitrification system.

Benzylalkyldimethylethyl ammonium compounds (BAC) and polyvinyl chloride microplastics (PVC MPs), as the frequently detected pollutants in wastewater treatment plants (WWTPs), have attracted more concerns on their ecosystem risks. Therefore, this study investigated how the sulfur autotrophic denitrification (SAD) system responded to the single and joint stress of PVC MPs (1, 10 and 100 mg/L) and BAC (0.5, 5 and 10 mg/L). After 100 days of operation, the presence of 10 mg/L BAC led to obviously inhibitory effects on system performance and microbial metabolic activity. And the additions of PVC MPs or/and BAC stimulated the proliferation of intracellular resistance genes (RGs), whereas exposure to BAC increased the abundances of extracellular RGs and free RGs in water more significantly. Compared to the joint stress, BAC single stress resulted in higher abundances of free RGs in water, which further increased the risk of RGs propagation. Moreover, the interaction between mobile genetic elements and extracellular polymeric substances further increased the spread of RGs. Pathogens might be the potential hosts of RGs and enriched in SAD system and plastisphere, thereby leading to more serious ecological risks. This study will broaden the understanding of the environmental hazards posed by PVC MPs and BAC in WWTPs.

Microplastics meet micropollutants in a central european river stream: Adsorption of pollutants to microplastics under environmentally relevant conditions.

Microplastics have emerged as pervasive pollutants in aquatic environments, and their interaction with organic contaminants poses a significant environmental challenge. This study aimed to explore the adsorption of micropollutants onto microplastics in a river, examining different plastic materials and the effect of aging on adsorption capacity. Microplastics (low-density polyethylene (LDPE), polyethylene terephthalate (PET), and polyvinyl chloride (PVC)) were introduced into a river stream, and a comprehensive analysis involving 297 organic pollutants was conducted. Passive samplers were deployed to monitor micropollutant presence in the river. Sixty-four analytes were identified in the river flow, with telmisartan being the most prevalent. Nonaged PVC showed the highest telmisartan concentration at 279 ng/g (168 ng/m2 regarding the microplastic surface), while aged PVC exhibited a fourfold decrease. Conversely, aged LDPE preferentially adsorbed metoprolol and tramadol, with concentrations increasing 12- and 3-fold, respectively, compared to nonaged LDPE. Azithromycin and clarithromycin, positively charged compounds, exhibited higher sorption to PET microplastics, regardless of aging. Diclofenac showed higher concentrations on nonaged PVC compared to aged PVC. Aging induced structural changes in microplastics, including color alterations, smaller particle production, and increased specific surface area. These changes influenced micropollutant adsorption, with hydrophobicity, dissociation constants, and the ionic form of pollutants being key factors. Aged microplastics generally showed different sorption properties. A comparison of microplastics and control sand particles indicated preferential micropollutant sorption to microplastics, underscoring their role as vectors for contaminant transport in aquatic ecosystems. Analysis of river sediment emphasized the significance of contact time in pollutant accumulation. Overall, this study provides insights into the complex interactions between microplastics and organic pollutants under environmental conditions and contributes to a better understanding of the fate and behavior of these two types of contaminants in aquatic ecosystems.

Hydrothermal dechlorination strategy for high-quality oil recovery from polyvinyl chloride.

The global production of PVC is around 3.5 million tons each year. Unfortunately, the disposal of PVC waste releases toxic substances such as hydrochloric acid, polychlorinated dioxins, and furans, which can harm the environment. Therefore, there is an urgent need for a safe and environmentally friendly thermochemical treatment method that reduces the damage caused by HCl gas produced during PVC pyrolysis and improves the quality of pyrolysis oil. Hydrothermal treatment technology is one of the potential dechlorination strategies for PVC. However, its efficiency is reduced in the supercritical region, while the additives used result in secondary pollution and increased operating costs. This study is pioneering in its approach, aiming to produce high-quality oil with reduced chlorine through low-temperature hydrothermal treatment of PVC, all without additives. The results are promising, indicating that by administering steam at 250 °C with a 2.0-3.0 g-steam/g-feed ratio, we can significantly reduce chlorine content to 0.13 % while achieving an oil yield of up to 14.9 % from PVC. The hydrothermal process can reduce CO2 emissions by 15-43 % compared to pyrolysis methods, providing a simultaneous opportunity for carbon neutrality and resource recovery.

Multi-Omics Analysis Reveals the Toxicity of Polyvinyl Chloride Microplastics toward BEAS-2B Cells.

Polyvinyl chloride microplastics (PVC-MPs) are microplastic pollutants widely present in the environment, but their potential risks to human lung health and underlying toxicity mechanisms remain unknown. In this study, we systematically analyzed the effects of PVC-MPs on the transcriptome and metabolome of BEAS-2B cells using high-throughput RNA sequencing and untargeted metabolomics technologies. The results showed that exposure to PVC-MPs significantly reduced the viability of BEAS-2B cells, leading to the differential expression of 530 genes and 3768 metabolites. Further bioinformatics analyses showed that PVC-MP exposure influenced the expression of genes associated with fluid shear stress, the MAPK and TGF-ß signaling pathways, and the levels of metabolites associated with amino acid metabolism. In particular, integrated pathway analysis showed that lipid metabolic pathways (including glycerophospholipid metabolism, glycerolipid metabolism, and sphingolipid metabolism) were significantly perturbed in BEAS-2B cells following PVC-MPs exposure. This study provides new insights and targets for a deeper understanding of the toxicity mechanism of PVC-MPs and for the prevention and treatment of PVC-MP-associated lung diseases.

Mechanism Involved in Polyvinyl Chloride Nanoplastics Induced Anaerobic Granular Sludge Disintegration: Microbial Interaction Energy, EPS Molecular Structure, and Metabolism Functions.

Nanoplastics (NPs) are emerging pollutants and have been reported to cause the disintegration of anaerobic granular sludge (AnGS). However, the mechanism involved in AnGS disintegration was not clear. In this study, polyvinyl chloride nanoplastics (PVC-NPs) were chosen as target NPs and their long-term impact on AnGS structure was investigated. Results showed that increasing PVC-NPs concentration resulted in the inhibition of acetoclastic methanogens, syntrophic propionate, and butyrate degradation, as well as AnGS disintegration. At the presence of 50 µg·L-1 PVC-NPs, the hydrophobic interaction was weakened with a higher energy barrier due to the relatively higher hydrophilic functional groups in extracellular polymeric substances (EPS). PVC-NPs-induced ROS inhibited quorum sensing, significantly downregulated hydrophobic amino acid synthesis, whereas it highly upregulated the genes related to the synthesis of four hydrophilic amino acids (Cys, Glu, Gly, and Lys), resulting in a higher hydrophily degree of protein secondary structure in EPS. The differential expression of genes involved in EPS biosynthesis and the resulting protein secondary structure contributed to the greater hydrophilic interaction, reducing microbial aggregation ability. The findings provided new insight into the long-term impact of PVC-NPs on AnGS when treating wastewater containing NPs and filled the knowledge gap on the mechanism involved in AnGS disintegration by PVC-NPs.

The influence of digestive tract protein on cytotoxicity of polyvinyl chloride microplastics.

Microplastics in food and drinking water can enter the human body through oral exposure, posing potential health risks to the human health. Most studies on the toxic effects of microplastics have focused on aquatic organisms, but the effects of the human digestive environment on the physicochemical properties of microplastics and their potential toxicity during gastrointestinal digestion are often limited. In this study, we first studied the influence of interactions between digestive tract protein (α-amylase, pepsin, and trypsin) and microplastics on the activity and conformation of digestive enzymes, and the physicochemical properties of polyvinyl chloride microplastics (PVC-MPs). Subsequently, a simulated digestion assay was performed to determine the biotransformation of PVC-MPs in the digestive tract and the intestinal toxicity of PVC-MPs. The in vitro experiments showed that the protein structure and activity of digestive enzymes were changed after adsorption by microplastics. After digestion, the static contact angle of PVC-MPs was decreased, indicating that the hydrophilicity of the PVC-MPs increased, which will increase its mobility in organisms. Cell experiment showed that the altered physicochemical property of PVC-MPs after digestion process also affect its cytotoxicity, including cellular uptake, cell viability, cell membrane integrity, reactive oxygen species levels, and mitochondrial membrane potential. Transcriptome analyses further confirmed the enhanced biotoxic effect of PVC-MPs after digestion treatment. Therefore, the ecological risk of microplastics may be underestimated owing to the interactions of microplastics and digestive tract protein during biological ingestion.

Limits, challenges, and opportunities of sampling groundwater wells with plastic casings for microplastic investigations.

Investigating microplastics (MPs) in groundwater suffers from problems already faced by surface water research, such as the absence of common protocols for sampling and analysis. While the use of plastic instruments during the collection, processing, and analysis of water samples is usually avoided in order to minimize unintentional contamination, groundwater research encompassing MPs faces unique challenges. Groundwater sampling typically relies on pre-existing monitoring wells (MWs) and water wells (WWs) that are often constructed with polyvinyl chloride (PVC) casings or pipes due to their favorable price-performance ratio. Despite the convenience, however, the suitability of PVC casings for MP research is questionable. Unfortunately, the specifics of these wells are often not detailed in published studies. Current literature does not indicate significant pollution risks from PVC casings, suggesting these wells might still be viable for MP studies. Our preliminary analysis of the existing literature indicates that if PVC exceeds 6 % of the total MP concentration, it is likely that casings and pipes made of PVC are a source of pollution. Above this threshold, additional investigations in MWs and WWs with PVC casings and pipes are suggested.

Polyvinyl chloride microplastics in the aquatic environment enrich potential pathogenic bacteria and spread antibiotic resistance genes in the fish gut.

Microplastics and antibiotics coexist in aquatic environments, especially in freshwater aquaculture areas. However, as the second largest production of polyvinyl chloride (PVC) in the world, the effects of co-exposure to microplastics particles and antibiotics on changes in antibiotic resistance gene (ARG) profiles and the microbial community structure of aquatic organism gut microorganisms are poorly understood. Therefore, in this study, carp (Cyprinus carpio) were exposed to single or combined PVC microplastic contamination and oxytetracycline (OTC) or sulfamethazine (SMZ) for 8 weeks. PVC microplastics can enrich potential pathogenic bacteria, such as Enterobacter and Acinetobacter, among intestinal microorganisms. The presence of PVC microplastics enhanced the selective enrichment and dissemination risk of ARGs. PVC microplastics combined with OTC (OPVC) treatment significantly increased the abundance of tetracycline resistance genes (1.40-fold) compared with that in the OTC exposure treatment, revealing an obvious co-selection effect. However, compared with those in the control group, the total abundance of ARGs and MGEs in the OPVC treatment groups were significantly lower, which was correlated with the reduced abundances of the potential host Enterobacter. Overall, our results emphasized the diffusion and spread of ARGs are more influenced by PVC microplastics than by antibiotics, which may lead to antibiotic resistance in aquaculture.

Hydrophilic catheters for intermittent catheterization and occurrence of urinary tract infections. A retrospective comparative study in patients with spinal cord Injury.

BACKGROUND: Neurogenic bladder dysfunction is a major problem for spinal cord injury (SCI) patients not only due to the risk of serious complications but also because of the impact on quality of life. The main aim of this study is to compare the rate of urinary tract infection (UTI) associated with hydrophilic-coated catheters versus uncoated polyvinyl chloride (PVC) catheters among SCI patients presenting with functional neurogenic bladder sphincter disorders. METHODOLOGY: This was a retrospective cohort study from 2005 to 2020 including adult male or female patients who have an SCI at least more than 1 month ago with neurogenic bladder dysfunction and were using intermittent catheterization (single-use hydrophilic-coated or the standard-of-care polyvinyl chloride uncoated standard catheters) at least 3 times a day to maintain bladder emptying. RESULTS: A total of 1000 patients were selected and recruited through a stratified random sampling technique with 467 (47.60%) patients in the uncoated catheter arm and 524 (52.60%) in the coated catheter groups. The three outcome measures, namely: symptomatic UTI, Bacteriuria, and pyuria were significantly higher in the group using uncoated polyvinyl chloride (PVC) catheters compared to hydrophilic-coated catheters at the rate of 79.60% vs.46.60%, 81.10% vs. 64.69, and 53.57% versus 41.79% respectively. Males, elder patients, longer duration, and severity of SCI were associated with increased risk of symptomatic UTI. CONCLUSIONS: The results indicate a beneficial effect regarding clinical UTI when using hydrophilic-coated catheters in terms of fewer cases of symptomatic UTI. Bacteriuria is inevitable in patients with long-term catheterization, however, treatment should not be started unless the clinical symptoms exist. More attention should be given to the high-risk group for symptomatic UTIs.

A Study of Plant-Filled Polymer Composites Based on Highly Plasticized Polyvinyl Chloride.

To enhance the ecological properties of polyvinyl chloride (PVC) products, the fabrication of PVC-based composites using biofillers with acceptable performance characteristics could be considered. In this work, plant-filled PVC-based composite materials were fabricated and their optical, structural, thermal, and mechanical properties, depending on the nature of the filler, were studied. Spruce flour, birch flour, and rice husk were used as fillers. Optical measurements showed the selected technological parameters, allowing films with a uniform distribution of dispersed plant filler in the polymer matrix to be obtained. Using the plant fillers in PVC films leads to a reduction in strength characteristics; for instance, the tensile strength changed from 18.0 MPa (for pure PVC film) to ~7 MPa (for composites with 20 wt.% of fillers), and to ~5-6.2 MPa (for composites with 40 wt.% of fillers). Thermal investigations showed that the samples with plant fillers could be used at low temperatures without changing their operating characteristics. Thus, plant-filled PVC-based composite materials have a wide operating temperature range, from-65 °C to 150 °C. TGA analysis has demonstrated that the rice husk affected the thermal stability of the composites by increasing their thermal decomposition resistance. The ability to absorb water was observed during the investigation of water absorption of the samples. And the highest degree of water absorption (up to 160 mg/g) was detected for the sample with 40 wt.% of rice husk. In general, plant-filled polymer composites based on PVC can be used on an equal basis with unfilled PVC plastic compounds for some applications such as in construction (for example, for design tasks).