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1.
Mol Clin Oncol ; 21(4): 66, 2024 Oct.
Article de Anglais | MEDLINE | ID: mdl-39091418

RÉSUMÉ

Radiotherapy (RT) is one of the most widely used and effective cancer treatments. With the increasing need for organ reconstruction and advancements in material technology, an increasing number of patients with cancer have metallic implants. These implants can affect RT dosage and clinical outcomes, warranting careful consideration by oncologists. The present review discussed the mechanisms by which different types of metallic implants impact various stages of the RT process, examined methods to mitigate these effects during treatment, and discussed the clinical implications of metallic implants on RT outcomes. In summary, when metallic implants are present within the RT field, oncologists should carefully assess their impact on the treatment.

2.
J Agric Food Chem ; 2024 Jul 25.
Article de Anglais | MEDLINE | ID: mdl-39051566

RÉSUMÉ

Abscisic acid (ABA) plays an important regulatory role in plants. It is very critical to obtain the dynamic changes of ABA in situ for botanical research. Herein, coupled with paper-based analysis devices, electrochemical immunoelectrodes based on disposable stainless steels sheet were developed for ABA detection in plants in situ. The stainless steel sheets were modified with carbon cement, ferrocene-graphene oxide-multi walled carbon nanotubes nanocomposites, and ABA antibodies. The system can detect the ABA in the range of 1 nM to 100 µM, with a limit of detection of 100 pM. The ABA content in tomato leaves under high salinity was detected in situ. The trend of ABA changes was similar to the expression of SlNCED1 and SlNCED2. Overall, this study offers an approach for in situ detection of ABA in plants, which will help to study the regulation mechanism of ABA in plants and to promote the development of precision agriculture.

3.
Heliyon ; 10(13): e33676, 2024 Jul 15.
Article de Anglais | MEDLINE | ID: mdl-39040417

RÉSUMÉ

Additively manufactured a low carbon Fe-Cr-Ni-Al Corrax stainless steel has ultra-high strength, but the mechanism at work when the steel cracks is still unclear. In this study, Corrax stainless steel was tensile tested to fracture and cracks in the vicinity of the fracture surface were analyzed by scanning electron microscope and electron-backscattered diffraction. The results show that the cracks propagated at angles of 45-60° to the tensile axis. Some cracks were transgranular, and high-angle grain boundaries had little effect on crack propagation. Crack propagation was inhibited in regions with lower Taylor factors. Kernel average misorientation value analysis established that the crack propagation process is accompanied by significant plastic deformation. The influence of particles and unfused pores on crack propagation is also discussed.

4.
J Colloid Interface Sci ; 675: 1011-1020, 2024 Jul 09.
Article de Anglais | MEDLINE | ID: mdl-39003814

RÉSUMÉ

Development of low-cost, efficient, and stable electrocatalysts for oxygen evolution reaction (OER) is the key issue for a large-scale hydrogen production. Recently, in-situ corrosion of stainless steel seems to be a feasible technique to obtain an efficient OER electrode, while a wide variety of corrosive agents often lead to significant difference in catalytic performance. Herein, we synthesized Ni-Fe based nanomaterials with OER activity through a facile one-step hydrothermal etching method of stainless steel mesh, and investigated the influence of three halogen oxyacid salts (KClO3, KBrO3, KIO3) on water oxidation performance. It was found that the reduction product of oxyacid salts has the pitting effect on the stainless steel, which plays an important role in regulating the morphology and composition of the nanomaterials. The KBrO3-derived electrode shows optimal OER performance, giving the small overpotential of 228 and 270 mV at 10 and 100 mA cm-2 respectively, a low Tafel slope of 36.2 mV dec-1, as well as durable stability in the long-time electrolysis. This work builds an internal relationship between the corrosive agents and the OER performance of the as-prepared electrodes, providing promising strategies and research foundations for further improving the OER performance and optimizing the structure of stainless steel electrodes.

5.
Chem Asian J ; : e202400314, 2024 Jul 16.
Article de Anglais | MEDLINE | ID: mdl-39014972

RÉSUMÉ

Stainless steel mesh (SSM) has emerged as a cornerstone in electrochemical applications owing to its exemplary versatility, electrical conductivity, mechanical robustness, and corrosion resistance. This state-of-the-art review delves into the diverse roles of SSM across a spectrum of electrochemical domains, including energy conversion and storage devices, water treatment technologies, electrochemical sensors, and catalysis. We meticulously explore its deployment in supercapacitors, batteries, and fuel cells, highlighting its utility as a current collector, electrode, and separator. The review further discusses the critical significance of SSM in water treatment processes, emphasizing its efficacy in supporting membranes and facilitating electrocoagulation, as well as its novel uses in electrochemical sensing and catalysis, which include electrosynthesis and bioelectrochemistry. Each section delineates the recent advancements, identifies the inherent challenges, and suggests future directions for leveraging SSM in electrochemical technologies. This comprehensive review showcases the current state of knowledge and articulates the novel integration of SSM with emerging materials and technologies, thereby establishing a new paradigm for sustainable and efficient electrochemical applications. Through critical analysis and insightful recommendations, this review positions itself as a seminal contribution, paving the way for researchers and practitioners to harness the full potential of SSM in advancing the electrochemistry frontiers.

6.
Materials (Basel) ; 17(13)2024 Jul 05.
Article de Anglais | MEDLINE | ID: mdl-38998407

RÉSUMÉ

The main objective of this work was to propose and evaluate a methodology for shielding-gas selection in additive manufacturing assisted by wire arc additive manufacturing (WAAM) with an austenitic stainless steel as feedstock. To validate the proposed methodology, the impact of multi-component gases was valued using three different Ar-based blends recommended as shielding gas for GMA (gas metal arc) of the target material, using CMT (cold metal transfer) as the process version. This assessment considered features that potentially affect the building of the case study of thin walls, such as metal transfer regularity, deposition time, and geometrical and metallurgical characteristics. Different settings of wire-feed speeds were conceived to maintain a similar mean current (first constraint for comparison's sake) among the three gas blends. This approach implied different mean wire-feed speeds and simultaneously forced a change in the deposition speed to maintain the same amount of material deposited per unit of length (second comparison constraint). The composition of the gases affects the operational performance of the shielding gases. It was concluded that by following this methodology, shielding-gas selection decision-making is possible based on the perceived characteristics of the different commercial blends.

7.
Heliyon ; 10(12): e33245, 2024 Jun 30.
Article de Anglais | MEDLINE | ID: mdl-39021934

RÉSUMÉ

Selecting adequate ferritic stainless steel (FSS) with a high corrosion resistance and a low cost is critical for solid oxide fuel cells (SOFCs) operating at intermediate temperature. In this study, the corrosion behaviors of four commercial FSSs involving TS430, TY441, YG442, and TY445 with a Cr content ranging from 16.18 wt.% to 21.73 wt.% are investigated at 650 °C. The oxidation mass gains, microstructures of surface oxide scale, and electrical conductivities are measured. The effects of grain size as well as doped elements are estimated together with the Cr volatilization. Flaky Cr2O3 particles are formed on TS430 and TY441 dominated by the outward migration of Cr3+. In comparison, a thin and dense layer of chromia is observed on YG442 and TY445. A high Cr content and a uniformly distributed grain size are conducive to the formation of a thin and dense chromia scale on the FSS surface during the initial oxidation process. On the other hand, the addition of Nb, Ti, and Mo weakens the outward diffusion of Cr3+ and reduces the particle size of chromia. After oxidation at 650 °C for 120 h, scattered (Mn, Cr)3O4 spinel particles occur on TS430, YG442, and TY445. TY445 and YG442 exhibit a higher conductivity although all the results of area specific resistance (ASR) are less than 6 mΩ·cm2. Meanwhile, the effect of Cr volatilization is enlarged on the estimation of mass gain at 650 °C compared with even higher temperatures.

8.
Food Res Int ; 191: 114613, 2024 Sep.
Article de Anglais | MEDLINE | ID: mdl-39059895

RÉSUMÉ

Glabridin is an antimicrobial compound which can be extracted from plants, such as liquorice (Glycyrrhiza glabra) roots. Although its activity against foodborne pathogens and spoilage microorganisms has already been reported, the investigation of potential applications as a surface disinfectant is still largely unexplored. Hence, this study evaluated the disinfectant efficacy of glabridin against Listeria monocytogenes. The activity of glabridin was first tested in vitro in a nutrient-rich medium against eight strains of L. monocytogenes, including food isolates and the model strain EGDe. The tested strains showed similar susceptibility with minimal inhibitory and bactericidal concentrations of 12.5 µg/mL and 25 µg/mL, respectively. Subsequently, L. monocytogenes L6, FBR17 and EGDe were selected to assess the efficacy of glabridin against dried cells (according to the European standard EN 13697:2015 + A1:2019) and biofilm cells on stainless steel surfaces. Moreover, the impact of food residual organic matter was investigated using skim milk, cantaloupe and smoked salmon solution as soiling components. Our results showed that applying 200 µg/mL of glabridin resulted in a substantial reduction (>3 log10) of dried and biofilm cells of L. monocytogenes in standard conditions (i.e. low level of residual organic matter). Cantaloupe soiling components slightly reduced the activity of glabridin, while the efficacy of glabridin when tested with salmon and skim milk residuals was substantially affected. Comparative analysis using standardized protein contents provided evidence that the type of food matrices and type of proteins may impact the activity of glabridin as a disinfectant. Overall, this study showed low strain variability for the activity of glabridin against L. monocytogenes and shed light on the possible application of this natural antimicrobial compound as a surface disinfectant.


Sujet(s)
Biofilms , Microbiologie alimentaire , Isoflavones , Listeria monocytogenes , Phénols , Listeria monocytogenes/effets des médicaments et des substances chimiques , Listeria monocytogenes/croissance et développement , Isoflavones/pharmacologie , Biofilms/effets des médicaments et des substances chimiques , Biofilms/croissance et développement , Phénols/pharmacologie , Désinfectants/pharmacologie , Tests de sensibilité microbienne , Acier inoxydable , Antibactériens/pharmacologie , Animaux
9.
Microorganisms ; 12(7)2024 Jul 09.
Article de Anglais | MEDLINE | ID: mdl-39065161

RÉSUMÉ

Copper-containing materials are attracting attention as self-disinfecting surfaces, suitable for helping healthcare settings in reducing healthcare-associated infections. However, the impact of repeated exposure to disinfectants frequently used in biocleaning protocols on their antibacterial activity remains insufficiently characterized. This study aimed at evaluating the antibacterial efficiency of copper (positive control), a brass alloy (AB+®) and stainless steel (negative control) after repeated exposure to a quaternary ammonium compound and/or a mix of peracetic acid/hydrogen peroxide routinely used in healthcare settings. A panel of six antibiotic-resistant strains (clinical isolates) was selected for this assessment. After a short (5 min) exposure time, the copper and brass materials retained significantly better antibacterial efficiencies than stainless steel, regardless of the bacterial strain or disinfectant treatment considered. Moreover, post treatment with both disinfectant products, copper-containing materials still reached similar levels of antibacterial efficiency to those obtained before treatment. Antibiotic resistance mechanisms such as efflux pump overexpression did not impair the antibacterial efficiency of copper-containing materials, nor did the presence of one or several genes related to copper homeostasis/resistance. In light of these results, surfaces made out of copper and brass remain interesting tools in the fight against the dissemination of antibiotic-resistant strains that might cause healthcare-associated infections.

10.
J Biomech ; 172: 112227, 2024 Jul.
Article de Anglais | MEDLINE | ID: mdl-39004042

RÉSUMÉ

Considering the high strength and excellent biocompatibility of low-nickel stainless steel, this paper focused on optimizing the design of a vascular stent made from this material using finite element analysis (FEA) combined with the response surface methodology (RSM). The aim is to achieve the desired compressive resistance for the stent while maintaining a thin stent wall thickness. The parameters of the stent's support unit width (H), strut width (W), and thickness (T) were selected as input parameters, while the output parameters obtained from FEA included the compressive load, the equivalent plastic strain (PEEQ), axial shortening rate, radial recoil rate, and metal coverage rate. The mathematical models of input parameters and output parameters were established by using the Box Behnken design (BBD) of RSM. The model equations were solved under constrained conditions, and the optimal structural parameters, namely H, W, and T, were finally determined as 0.770 mm, 0.100 mm, and 0.075 mm respectively. In this situation, the compression load of the stent reached the target value of 0.38 N/mm; the PEEQ resulting from the stent expansion was small; the axial shortening, radial recoil, and metal coverage index were all minimized within the required range.


Sujet(s)
Résistance à la compression , Analyse des éléments finis , Acier inoxydable , Endoprothèses , Humains , Nickel , Contrainte mécanique , Conception de prothèse , Modèles cardiovasculaires , Test de matériaux
11.
Materials (Basel) ; 17(14)2024 Jul 09.
Article de Anglais | MEDLINE | ID: mdl-39063681

RÉSUMÉ

In this paper, the deformation behavior of UNS S32750 (S32750) duplex stainless steel during low cycle fatigue was studied by controlling the number of cycles. The microstructure of the specimens under different cycles was characterized by optical microscope (OM), scanning electron microscope (SEM), electron backscatter diffraction (EBSD), and transmission electron microscope (TEM). The microhardness of the two phases was measured by a digital microhardness instrument. The results showed that the microhardness of ferrite increases significantly after the first 4000 cycles, while the austenite shows a higher strain hardening rate after fatigue fracture, and the microhardness of ferrite and austenite increases by 23 HV and 87 HV, respectively. The two-phase kernel average misorientation (KAM) diagram showed that the continuous accumulation of plastic deformation easily leads to the initiation of cracks inside the austenite and at the phase boundaries. The evolution of dislocation morphology in the two phases was obviously different. With the increase in cycle number, the dislocation in ferrite gradually transforms from dislocation bundles and a dislocation array to a sub-grain structure, while the dislocation in austenite gradually develops from dipole array to an ordered Taylor lattice network structure.

12.
Materials (Basel) ; 17(14)2024 Jul 14.
Article de Anglais | MEDLINE | ID: mdl-39063778

RÉSUMÉ

Friction stir welding was utilized to obtain high-quality SUS301L stainless steel joints, whose mechanical and corrosion properties were thoroughly evaluated. Sound joints were obtained with a wide range of rotational velocities from 400 to 700 rpm. The microstructures of the stir zone primarily consisted of austenite and lath martensite without the formation of detrimental phases. The ultimate tensile strength of the welded joints improved with higher rotational velocities apart from 400 rpm. The ultimate tensile strength reached 813 ± 16 MPa, equal to 98.1 ± 1.9% of the base materials (BMs) with a rotational velocity of 700 rpm. The corrosion resistance of the FSW joints was improved, and the corrosion rates related to uniform corrosion with lower rotational velocities were one order of magnitude lower than that of the BMs, which was attributed to the lower martensite content. However, better anti-pitting corrosion performance was obtained with a high rotational velocity of 700 rpm, which was inconsistent with the uniform corrosion results. It could be speculated that a higher martensitic content had a negative effect on the uniform corrosion performance, but had a positive effect on the improvement of the anti-pitting corrosion ability.

13.
Materials (Basel) ; 17(14)2024 Jul 15.
Article de Anglais | MEDLINE | ID: mdl-39063786

RÉSUMÉ

The oxidation behaviour of iron-based 316L stainless steel was investigated in the temperature range of 700 to 1000 °C. The test specimens in the shape of plates were produced by selective laser melting. After fabrication, the samples were sandblasted and then annealed in air for different periods of time (0.5, 2, 8, 32 h). Under the influence of temperature and time, stainless steels tend to form an oxide layer. Scanning electron microscopy, energy dispersive analysis, and X-ray diffraction were employed to analyse the composition of this layer. Notably, a thin oxide layer primarily composed of (Fe-Cr) formed on the surface due to temperature effects. In addition, with increasing temperature (up to 1000 °C), the oxide of the main alloying elements, specifically Mn2(Fe-Cr)O4, appeared alongside the Fe-Cr oxide. Furthermore, the samples were subjected to conversion X-ray (CXMS) and conversion electron (CEMS) Mössbauer spectroscopy. CXMS revealed a singlet with a decreasing Mössbauer effect based on the surface metal oxide thickness. CEMS revealed the presence of Fe3+ in the surface layer (0.3 µm). Moreover, an interesting phenomenon occurred at higher temperature levels due to the inhomogeneously thick surface metal oxide layer and the tangential direction of the Mössbauer radiation towards the electron detector.

14.
Materials (Basel) ; 17(14)2024 Jul 20.
Article de Anglais | MEDLINE | ID: mdl-39063881

RÉSUMÉ

In this paper, a Cr coating was prepared by induction heating and pack-cementation chromizing on AISI 304 austenitic stainless steel. Then, the cold-rolling deformation and annealing treatment were introduced to refine the coarse matrix grains caused by pack-chromizing and improve the overall performance of 304 austenitic stainless steel. The phase composition, element distribution, and microstructure of the coating were carefully characterized. The microhardness, wear resistance, and corrosion resistance of the coating were tested. The results show that the Cr coating with a thickness of 100 µm is mainly composed of a (Cr,Fe)23C6, (Cr,Fe)7C3, and α-Fe-Cr solid solution. After the cold-rolling deformation and subsequent annealing treatment, the grains are significantly refined and the Cr coating is divided into two layers, consisting of carbon-chromium compounds such as Cr23C6, Cr7C3, Cr2C, and Cr3C2 in the surface layer and a Fe-Cr solid solution in the subsurface layer. The cold-rolling deformation and annealing treatment significantly improved the microhardness and wear resistance of the coated sample, and the corrosion resistance was also better than that of the uncoated sample.

15.
Materials (Basel) ; 17(14)2024 Jul 22.
Article de Anglais | MEDLINE | ID: mdl-39063912

RÉSUMÉ

The Z-pinch device is a critical component in inertial confinement fusion, where stainless steel electrodes must withstand high current densities of up to MA/cm2. Gases and difficult-to-remove impurities adhering to the electrode surfaces can ionize, significantly impacting the device's electrical conductivity efficiency. In this paper, the surface of stainless steel electrodes was subjected to cleaning using a large-area plasma jet under atmospheric pressure. The wettability, chemical composition, and chemical state of the electrode surface were characterized using a water contact angle measuring instrument and X-ray photoelectron spectroscopy (XPS). The cleaning effect under different discharge parameters was systematically analyzed. The results revealed a significant reduction in the content of carbon pollutants on the surface of stainless steel electrodes, decreasing from 62.95% to a minimum of 37.68% after plasma cleaning. Moreover, the water contact angle decreased from 70.76° to a minimum of 29.31°, and the content of water molecules adsorbed on the surface decreased from 17.31% to a minimum of 5.9%. Based on the evolution process of micro-element content and chemical state on the surface of stainless steel electrode, the cleaning process of adhering substances on the surface by atmospheric pressure plasma was analyzed by the layered cleaning model for surface pollutants on stainless steel.

16.
Micromachines (Basel) ; 15(7)2024 Jun 28.
Article de Anglais | MEDLINE | ID: mdl-39064348

RÉSUMÉ

The aim of this work is to study the phase transformations, microstructures, and mechanical properties of martensitic stainless steel (MSS) 410 deposits produced by laser powder-directed energy deposition (LP-DED) additive manufacturing. The LP-DED MSS 410 deposits underwent post-heat treatment, which included austenitizing at 980 °C for 3 h, followed by different tempering treatments at the temperatures of 250, 600, and 750 °C for 5 h, respectively. The analyses of phase transformations and microstructural evolutions of LP-DED MSS 410 were carried out using X-ray diffraction, SEM-EDS, and EBSD. Vickers hardness and tensile strength properties were also measured to analyze the effects of the different tempering heat treatments. It revealed that the as-built MSS 410 has very fine lath martensite, high hardness of about 480 HV1.0, and tensile strength of about 1280 MPa, but elongation was much lower than the post-heat-treated ones. Precipitations of chromium carbide (Cr23C6) were most commonly observed at the grain boundaries and the entire matrix at the tempering temperatures of 600 °C and 750 °C. In general, the tensile strength decreased from 1381 MPa to 688 MPa as tempering temperatures increased to 750 °C from 250 °C. Additionally, as the tempering temperature increased, the chromium carbide and tempered martensite structures became coarser.

17.
Micromachines (Basel) ; 15(7)2024 Jul 20.
Article de Anglais | MEDLINE | ID: mdl-39064440

RÉSUMÉ

Preparing elastic substrates as a carrier for dual-end supported nickel chromium thin film strain sensors is crucial. Wet etching is a vital microfabrication process widely used in producing microelectronic components for various applications. This article combines lithography and wet etching methods to microprocess the external dimensions and rectangular grooves of 304 stainless steel substrates. The single-factor variable method was used to explore the influence mechanism of FeCl3, HCl, HNO3, and temperature on the etching rate, etching factor, and etching surface roughness. The optimal etching parameter combination was summarized: an FeCl3 concentration of 350 g/L, HCl concentration of 150 mL/L, HNO3 concentration of 100 mL/L, and temperature of 40 °C. In addition, by comparing the surface morphology, microstructure, and chemical and mechanical properties of a 304 stainless steel substrate before and after etching treatment, it can be seen that the height difference of the substrate surface before and after etching is between 160 µm and -70 µm, which is basically consistent with the initial design of 0.2 mm. The results of an XPS analysis and Raman spectroscopy analysis both indicate that the surface C content increases after etching, and the corrosion resistance of the surface after etching decreases. The nano-hardness after etching increased by 26.4% compared to before, and the ζ value decreased by 7%. The combined XPS and Raman results indicate that the changes in surface mechanical properties of 304 stainless steel substrates after etching are mainly caused by the formation of micro-nanostructures, grain boundary density, and dislocations after wet etching. Compared with the initial rectangular substrate, the strain of the I-shaped substrate after wet etching increased by 3.5-4 times. The results of this study provide the preliminary process parameters for the wet etching of a 304 stainless steel substrate of a strain measuring force sensor and have certain guiding significance for the realization of simple steps and low cost of 304 stainless steel substrate micro-nano-processing.

18.
Anal Chim Acta ; 1316: 342875, 2024 Aug 08.
Article de Anglais | MEDLINE | ID: mdl-38969433

RÉSUMÉ

BACKGROUND: Indole-3-acetic acid (IAA) and salicylic acid (SA), pivotal regulators in plant growth, are integral to a variety of plant physiological activities. The ongoing and simultaneous monitoring of these hormones in vivo enhances our comprehension of their interactive and regulatory roles. Traditional detection methods, such as liquid chromatography-mass spectrometry, cannot obtain precise and immediate information on IAA and SA due to the complexity of sample processing. In contrast, the electrochemical detection method offers high sensitivity, rapid response times, and compactness, making it well-suited for in vivo or real-time detection applications. RESULTS: A microneedle electrochemical sensor system crafted from disposable stainless steel (SS) wire was specifically designed for the real-time assessment of IAA and SA in plant in situ. This sensor system included a SS wire (100 µm diameter) coated with carbon cement and multi-walled carbon nanotubes, a plain platinum wire (100 µm diameter), and an Ag/AgCl wire (100 µm diameter). Differential pulse voltammetry and amperometry were adopted for detecting SA and IAA within the range of 0.1-20 µM, respectively. This sensor was applied to track IAA and SA fluctuations in tomato leaves during PstDC3000 infection, offering continuous data. Observations indicated an uptick in SA levels following infection, while IAA production was suppressed. The newly developed disposable SS wire-based microneedle electrochemical sensor system is economical, suitable for mass production, and inflicts minimal damage during the monitoring of SA and IAA in plant tissues. SIGNIFICANCE: This disposable microneedle electrochemical sensor facilitates in vivo detection of IAA and SA in smaller plant tissues and allows for long-time monitoring of their concentrations, which not only propels research into the regulatory and interaction mechanisms of IAA and SA but also furnishes essential tools for advancing precision agriculture.


Sujet(s)
Techniques électrochimiques , Acides indolacétiques , Feuilles de plante , Acide salicylique , Solanum lycopersicum , Acier inoxydable , Solanum lycopersicum/composition chimique , Acides indolacétiques/analyse , Acide salicylique/analyse , Feuilles de plante/composition chimique , Feuilles de plante/métabolisme , Acier inoxydable/composition chimique , Techniques électrochimiques/instrumentation , Aiguilles , Maladies des plantes/microbiologie
19.
Biofilm ; 8: 100211, 2024 Dec.
Article de Anglais | MEDLINE | ID: mdl-39071174

RÉSUMÉ

The ever-increasing use of exogenous materials as indwelling medical devices in modern medicine offers to pathogens new ways to gain access to human body and begin, in some cases, life threatening infections. Biofouling of such materials with bacteria or fungi is a major concern during surgeries, since this is often associated with biofilm formation and difficult to treat, recalcitrant infections. Intense research efforts have therefore developed several strategies to shield the medical devices' surface from colonization by pathogenic microorganisms. Here, we used dopamine as a coupling agent to coat four different materials of medical interest (plastic polyetheretherketone (PEEK), stainless steel, titanium and silicone catheter) with the bacteriocins, enterocin EJ97-short and the thiopeptide micrococcin P1. Water contact angle measurements and x-ray photoelectron spectroscopy were used to verify the effective coating of the materials. The effect of bacteriocins coated on these materials on the biofilm formation by a vancomycin resistant Enterococcus faecium (VRE) strain was studied by biofilm-oriented antimicrobial test (BOAT) and electron scanning microscopy. The in vitro biocompatibility of bacteriocin-modified biomaterials was tested on cultured human cells. The results demonstrated that the binding of the bacteriocins to the implant surfaces is achieved, and the two bacteriocins in combination could inhibit biofilm formation by E. faecium on all four materials. The modified implant showed no cytotoxicity to the human cells tested. Therefore, surface modification with the two bacteriocins may offer a novel and effective way to prevent biofilm formation on a wide range of implant materials.

20.
J Pharm Bioallied Sci ; 16(Suppl 2): S1526-S1530, 2024 Apr.
Article de Anglais | MEDLINE | ID: mdl-38882832

RÉSUMÉ

The stainless-steel crown (SSC) is a durable restoration and has several indications for use in primary teeth such as following a pulpotomy/pulpectomy, fractured teeth, teeth with developmental defects, or large multi-surface caries lesions where amalgam is likely to fail. Due to its durability and a lifespan like the primary tooth, it could well be the gold standard in restorative care. SSCs protect the crown from fracture, reduce the possibility for leakage, and ensure a biological seal. However, the placement of the SSC should follow a meticulous technique. There are some clinical situations where the SSC may fail, leading to plaque accumulation and gingivitis. This could be secondary to improper crimping of crown margins, which lead to poorly adapted SSC. In some clinical situations, ledge formation under the crown or failure to clean excess cement can contact the gingiva and cause gingival inflammation. This study was carried out on 41 children between the ages of 4 and 10 in Al Qassim region to study the effects of SSCs on gingiva and oral hygiene. The study also aims to establish the correlation between SSC adaptation and post-insertion inflammation. The plaque and gingival index were recorded at 3 months' post SSC insertion. Clinical examination was undertaken, and gingival index (Loe and Silness 1967) and plaque index (Silness and Loe 1967) were used to record gingival health and plaque accumulation, respectively. The result for post-inflammation and SSC adaptation showed that there was no statistically significant difference in post-insertion inflammation and crown adaptation (P value = 0.216). The result for pre-operative inflammation and post-operative inflammation shows that there is no significant difference in post-inflammation and adaptation (P value = 0.47). We found that oral hygiene care had a heightening effect and oral hygiene maintenance plays a key role in preventing gingival inflammation irrespective of the SSC adaptation over short periods of time (3 months).

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