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Materials (Basel, Switzerland) May 2024Natural fiber composites have been extensively studied for structural applications, with recent exploration into their potential for various uses. This study...
Natural fiber composites have been extensively studied for structural applications, with recent exploration into their potential for various uses. This study investigates the impact of chemical treatments on the properties of Brazilian jute woven fabric/polyester resin composites. Sodium hydroxide, hydrogen peroxide, and peracetic acid were utilized to treat the jute fabrics, followed by resin transfer molding (RTM) to form the composites. Evaluation included water absorption, flexural strength, tensile strength, and short-beam strength. The alkaline treatment induced changes in the chemical composition of the fibers' surface. Chemical treatments resulted in increased flexural and short-beam strength of the composites, with no significant alterations in tensile properties. The hydrogen peroxide treatment exhibited lower water absorption, suggesting its potential as a viable option for enhancing the performance of these composites.
PubMed: 38793387
DOI: 10.3390/ma17102320 -
Microorganisms May 2024The aim of this study was to test the inactivation of viruses on germ carriers of different types of wood using a disinfectant in order to assess the biosafety of wood...
The aim of this study was to test the inactivation of viruses on germ carriers of different types of wood using a disinfectant in order to assess the biosafety of wood as a building material in animal husbandry. The laboratory disinfectant efficacy tests were based on German testing guidelines and current European standards. Five different types of wood germ carriers, i.e., spruce (), pine (), poplar ( sp.), beech () and Douglas fir (), were inoculated with enveloped or non-enveloped viruses and then treated with one of three different disinfectants. The results revealed that intact, fine-sawn timber with a low roughness depth can be effectively inactivated. Peracetic acid proved to be the most effective disinfectant across all tests. Regardless of the pathogen and the type of wood, a concentration of 0.1% of the pure substance at a temperature of 10 °C and an exposure time of one hour can be recommended. At a temperature of -10 °C, a concentration of 0.75% is recommended. The basic chemicals formic acid and glutaraldehyde demonstrated only limited effectiveness overall. The synergistic effects of various wood components on the inactivation of viruses offer potential for further investigation. Disinfectant tests should also be conclusively verified in field trials to ensure that the results from standardised laboratory tests can be transferred to real stable conditions.
PubMed: 38792848
DOI: 10.3390/microorganisms12051019 -
Foods (Basel, Switzerland) May 2024This study investigated the antimicrobial effects of lactic acid (LA) (3%) and peracetic acid (PA) (300 ppm) on tilapia fillets () by fogging (15 min) or by immersion (2...
This study investigated the antimicrobial effects of lactic acid (LA) (3%) and peracetic acid (PA) (300 ppm) on tilapia fillets () by fogging (15 min) or by immersion (2 s) in a pool of (NEWP 0022, ATCC 25922, and a field-isolated strain), (ATCC 25923 and a field-isolated strain), and Typhimurium (ATCC 13311 and ATCC 14028), as well as the effects on the physicochemical characteristics of the fillets. Fogging was effective and the best application method to control . Typhimurium regardless of the acid used, promoting reductions of 1.66 and 1.23 log CFU/g with PA and LA, respectively. Regarding , there were significant reductions higher than 1 log CFU/g, regardless of the treatment or acid used. For , only immersion in PA showed no significant difference ( < 0.05). For other treatments, significant reductions of 0.98, 1.51, and 1.17 log CFU/g were observed for nebulized PA, immersion, and LA fogging, respectively. Concerning the pH of the samples, neither of the acids used differed from the control. However, treatments with LA, and fogging with PA, reduced the pH compared to immersion in PA. As for color parameters, L* and a* values showed changes regardless of the acid or method used, resulting in an improved perception of fillet quality. These results indicate that fogging and immersion are alternatives for reducing Typhimurium, , and in tilapia fillets.
PubMed: 38790821
DOI: 10.3390/foods13101520 -
Journal of Food Protection May 2024Salmonella is capable of surviving dehydration within various foods, such as dried fruit. Dried fruit, including apple slices, have been the subject of product recalls...
Salmonella is capable of surviving dehydration within various foods, such as dried fruit. Dried fruit, including apple slices, have been the subject of product recalls due to contamination with Salmonella. A study was conducted to determine the fate of Salmonella on apple slices, following immersion in three antimicrobial solutions (viz., ε-polylysine [epsilon-polylysine or EP], sodium bisulfate [SBS], or peracetic acid [PAA]), and subsequent hot air dehydration. Gala apples were aseptically cored and sliced into 0.4 cm thick rings, bisected, and inoculated with a five-strain composite of desiccation-resistant Salmonella, to a population of 8.28 log CFU/slice. Slices were then immersed for 2 min in various concentrations of antimicrobial solutions, including EP (0.005, 0.02, 0.05, and 0.1%), SBS (0.05, 0.1, 0.2, and 0.3%), PAA (18 or 42 ppm), or varying concentrations of PAA + EP, and then dehydrated at 60°C for 5 h. Salmonella populations in positive control samples (inoculated apple slices washed in sterile water) declined by 2.64 log after drying. In the present study, the inactivation of Salmonella, following EP and SBS treatments, increased with increasing concentrations, with maximum reductions of 3.87 and 6.20 log (with 0.1 and 0.3% of the two compounds, respectively). Based on preliminary studies, EP concentrations greater than 0.1% did not result in lower populations of Salmonella. Pretreatment washes with either 18 or 42 ppm of PAA inactivated Salmonella populations by 4.62 and 5.63 log, respectively, following desiccation. Combining PAA with up to 0.1% EP induced no greater population reductions of Salmonella than washing with PAA alone. The addition of EP to PAA solutions appeared to destabilize PAA concentrations, reducing its biocidal efficacy. These results may provide antimicrobial predrying treatment alternatives to promote the reduction of Salmonella during commercial or consumer hot air drying of apple slices.
PubMed: 38734414
DOI: 10.1016/j.jfp.2024.100297 -
Journal of Clinical and Experimental... Apr 2024The aim of this review was to assess the evidence regarding the most commonly used chelating agents in terms of efficacy, erosive potential, cytotoxicity, interaction,... (Review)
Review
BACKGROUND
The aim of this review was to assess the evidence regarding the most commonly used chelating agents in terms of efficacy, erosive potential, cytotoxicity, interaction, antimicrobial effect, impact on sealers adhesion, and release of growth factors.
MATERIAL AND METHODS
MEDLINE (PubMed) database, Cochrane Library and Scopus were searched up to January 14, 2023, including studies with one or more of the following chelating agents: 17% EDTA, 9% and 18% HEDP, 10% and 20% citric acid, 2%-2.25% peracetic acid and 7% maleic acid. In addition, the reference lists of all selected articles were also checked to identify additional relevant studies. Articles published in English and available in full-text were selected. The quality of studies was assessed using the modified CONSORT checklist guide and the Cochrane Collaboration tool.
RESULTS
The electronic search yielded 538 citations, 56 of which were included. The articles included had moderate and low evidence values. Among 56 articles included, 55 were in vitro studies and one was a randomized clinical trial. Among the in vitro studies, 15 evaluated efficacy and dentin erosion, 12 evaluated interaction with other endodontic irrigants, 9 tested antimicrobial effect, 4 evaluated cytotoxicity in hamster and rat lung cells, 9 evaluated intervention in adhesion of filling materials and 8 focused on release of growth factors and on behavior of stem cells in regenerative endodontic. The RCT tested antimicrobial effect.
CONCLUSIONS
17% EDTA is the most effective in smear layer removal and in releasing growth factors on regenerative endodontics. However, the current incorporation of 9% and 18% etidronic acid has shown optimal results due to its compatibility with sodium hypochlorite and its capability on avoiding smear layer formation through a continuous chelation action. Despite these preliminary findings, methodological standardization between studies is required and in vivo studies are necessary to confirm in vitro studies. Chelating Agents, Smear Layer, Systematic Review, Endodontics, Root Canal Irrigants.
PubMed: 38725809
DOI: 10.4317/jced.60989 -
PloS One 2024Ricin is a highly toxic protein, capable of inhibiting protein synthesis within cells, and is produced from the beans of the Ricinus communis (castor bean) plant....
Ricin is a highly toxic protein, capable of inhibiting protein synthesis within cells, and is produced from the beans of the Ricinus communis (castor bean) plant. Numerous recent incidents involving ricin have occurred, many in the form of mailed letters resulting in both building and mail sorting facility contamination. The goal of this study was to assess the decontamination efficacy of several commercial off-the-shelf (COTS) cleaners and decontaminants (solutions of sodium hypochlorite [bleach], quaternary ammonium, sodium percarbonate, peracetic acid, and hydrogen peroxide) against a crude preparation of ricin toxin. The ricin was inoculated onto four common building materials (pine wood, drywall joint tape, countertop laminate, and industrial carpet), and the decontaminants were applied to the test coupons using a handheld sprayer. Decontamination efficacy was quantified using an in-vitro cytotoxicity assay to measure the quantity of bioactive ricin toxin extracted from test coupons as compared to the corresponding positive controls (not sprayed with decontaminant). Results showed that decontamination efficacy varied by decontaminant and substrate material, and that efficacy generally improved as the number of spray applications or contact time increased. The solutions of 0.45% peracetic acid and the 20,000-parts per million (ppm) sodium hypochlorite provided the overall best decontamination efficacy. The 0.45% peracetic acid solution achieved 97.8 to 99.8% reduction with a 30-min contact time.
Topics: Ricin; Decontamination; Sodium Hypochlorite; Construction Materials; Peracetic Acid; Hydrogen Peroxide; Animals; Disinfectants
PubMed: 38722908
DOI: 10.1371/journal.pone.0302967 -
Biofilm Jun 2024is a Gram-positive non-motile bacterium capable of producing biofilms that contribute to the colonization of surfaces in a range of different environments. In this...
is a Gram-positive non-motile bacterium capable of producing biofilms that contribute to the colonization of surfaces in a range of different environments. In this study, we compared two strains, WCFS1 and CIP104448, in their ability to produce biofilms in static and dynamic (flow) environments using an in-house designed flow setup. This flow setup enables us to impose a non-uniform flow velocity profile across the well. Biofilm formation occurred at the bottom of the well for both strains, under static and flow conditions, where in the latter condition, CIP104448 also showed increased biofilm formation at the walls of the well in line with the higher hydrophobicity of the cells and the increased initial attachment efficacy compared to WCFS1. Fluorescence and scanning electron microscopy showed open 3D structured biofilms formed under flow conditions, containing live cells and ∼30 % damaged/dead cells for CIP104448, whereas the WCFS1 biofilm showed live cells closely packed together. Comparative proteome analysis revealed minimal changes between planktonic and static biofilm cells of the respective strains suggesting that biofilm formation within 24 h is merely a passive process. Notably, observed proteome changes in WCFS1 and CIP104448 flow biofilm cells indicated similar and unique responses including changes in metabolic activity, redox/electron transfer and cell division proteins for both strains, and myo-inositol production for WCFS1 and oxidative stress response and DNA damage repair for CIP104448 uniquely. Exposure to DNase and protease treatments as well as lethal concentrations of peracetic acid showed highest resistance of flow biofilms. For the latter, CIP104448 flow biofilm even maintained its high disinfectant resistance after dispersal from the bottom and from the walls of the well. Combining all results highlights that biofilm structure and matrix, and physiological state and stress resistance of cells is strain dependent and strongly affected under flow conditions. It is concluded that consideration of effects of flow on biofilm formation is essential to better understand biofilm formation in different settings, including food processing environments.
PubMed: 38706985
DOI: 10.1016/j.bioflm.2024.100197 -
The Journal of Hospital Infection May 2024The role of the healthcare environment in the transmission of clinical pathogens is well established. EN 17126:2018 was developed to address the need for regulated...
BACKGROUND
The role of the healthcare environment in the transmission of clinical pathogens is well established. EN 17126:2018 was developed to address the need for regulated sporicidal product testing and includes a realistic medical soil to enable validation of products that claim combined cleaning and disinfection efficacy.
AIM
To investigate the chemical stability and sporicidal efficacy of oxidizing disinfectant products in the presence of simulated clean and medical dirty conditions.
METHODS
Disinfectant stability and sporicidal efficacy were evaluated in like-for-like ratios of soil:product. Disinfectants were exposed to simulated test soils and free chlorine, chlorine dioxide or peracetic acid concentrations were measured using standard colorimetric methods. Efficacy of disinfectants against C. difficile R027 endospores was assessed as per EN 17126:2018. Comparisons of performance between clean and medical dirty conditions were performed using one-way analysis of variance. Correlation analysis was performed using Pearson product-moment correlation.
FINDINGS
Performance of chlorine-releasing agents (sodium dichloroisocyanurate, chlorine dioxide and hypochlorous acid) was concentration dependent, with 1000 ppm chlorine showing reduced stability and efficacy in dirty conditions. By contrast, peracetic acid product demonstrated stability and consistently achieved efficacy in dirty conditions.
CONCLUSION
These results have implications for clinical practice, as ineffective environmental decontamination may increase the risk of transmission of pathogens that can cause healthcare-associated infections.
PubMed: 38705474
DOI: 10.1016/j.jhin.2024.04.010 -
Cureus Mar 2024Therapeutic plasma exchange (TPE) is used to manage various life-threatening illnesses. It is widely performed by nephrologists, intensivists, pathologists, or experts...
INTRODUCTION
Therapeutic plasma exchange (TPE) is used to manage various life-threatening illnesses. It is widely performed by nephrologists, intensivists, pathologists, or experts in transfusion medicine worldwide. However, the costs of TPE sessions are exceedingly high, and they have a huge impact on patients' financial burden. Herein, we investigated the outcomes of the reuse of plasma filters in TPE on several occasions.
METHODS
This is a retrospective analysis of patients receiving TPE from January 1, 2020, to April 30, 2023, in the Department of Nephrology. A formulation of 4.5% peracetic acid and 24% hydrogen peroxide acid with RO water dilution was used for reprocessing. Clinical outcomes, risks, and cost-benefit were evaluated and compared between the plasma filter reuse group (GP-1) and the no-reuse group (GP-2).
RESULTS
A total of 70 patients were included in this study. 200 and 112 TPE sessions were performed in GP-1 and GP-2, respectively. The most common indication for TPE in both groups was neurological. The clinical efficacy of TPE was similar in both groups. There was no difference in the clotting of the plasma filter, any allergic reaction, infection, or bleeding in the group. However, there was a significant difference in levels of fibrinogen (p=0.03) pre and post-procedure in both groups. The incidence of hypotension was found to be higher in GP-1 (26%) compared to GP-2 (15.6%), p = 0.05. The cost of overall treatment was 38% less in GP-1.
CONCLUSION
The reuse of plasma filters is a safe and effective method for cost minimization in patients requiring TPE. This method can be effectively utilized in resource-poor settings without any increased risk of adverse effects.
PubMed: 38646327
DOI: 10.7759/cureus.56516 -
Water Research Jun 2024Micropollutants and bacteria are prevalent pollutants in wastewater, posing significant risks to ecosystems and human health. As peracetic acid (PAA) is being...
Regulating charge transfer for enhanced PAA activation over sulfur-doped magnetic CoFeO: A novel strategy for simultaneous micropollutants degradation and bacteria inactivation.
Micropollutants and bacteria are prevalent pollutants in wastewater, posing significant risks to ecosystems and human health. As peracetic acid (PAA) is being increasingly used as a disinfectant, activation of PAA by low-cost and high-performance activators is a promising strategy for wastewater treatment. In this study, the sulfur-doped magnetic CoFeO (SCFO) is successfully developed for efficient PAA activation to simultaneously decontaminate and disinfect wastewater. PAA/SCFO-0.3 exhibits exceptional performance, degrading 100 % of 8 μM sulfamethoxazole (SMX) with a first-pseudo reaction rate of 1.275 min, and achieving 5.3-log inactivation of Escherichia coli (E. coli) within 3 min at a PAA dosage of 0.2 mM and catalyst dosage of 0.025 g/L (initial pH 6.5). Scavenging experiments and electron paramagnetic resonance (EPR) analysis identify CHC(O)O and CHC(O)OO as the dominant reactive species for SMX degradation. The sulfur species in SCFO-0.3 facilitate Co regeneration and regulate charge transfer, promoting PAA activation for SMX degradation. Moreover, the PAA/SCFO-0.3 system demonstrates operational feasibility over a broad range of water matrices and has excellent stability and reusability (maintaining 93 % removal of SMX after 5 cycles), demonstrating its potential for industrial applications. This study provides insights into enhancing PAA activation through sulfur doping in transition metal catalysts and highlights the practical applicability of the PAA/SCFO-0.3 system as an advanced alternative to conventional disinfection for simultaneous decontamination and disinfection in wastewater.
Topics: Escherichia coli; Sulfur; Wastewater; Peracetic Acid; Cobalt; Ferric Compounds; Water Pollutants, Chemical
PubMed: 38640561
DOI: 10.1016/j.watres.2024.121595