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Orthopedic implants must meet specific criteria, including mechanical strength, durability, and biocompatibility. This study compares the immune response of zirconia, polyether ether ketone (PEEK), and stainless-steel implants in vivo, focusing on lymphocyte and fibroblast infiltration as indicators of immune activation. A total of 27 New Zealand white rabbits were used, with nine animals in each group. Implants of zirconia, PEEK, or stainless steel were surgically placed in the thigh and observed for 4 weeks. Histological analysis measured lymphocyte and fibroblast infiltration at the implant site using a microscope at 400x magnification. Statistical analysis included the Kruskal-Wallis test for group comparisons, followed by Mann-Whitney and Bonferroni correction for pairwise comparisons. The Kruskal-Wallis test showed significant differences in lymphocyte (p=0.002) and fibroblast (p=0.003) counts among the groups. Zirconia exhibited significantly lower lymphocyte (median=0.5) and fibroblast (median=1.0) infiltration compared to stainless steel (lymphocytes: median=3.0, fibroblasts: median=2.0), and PEEK (lymphocytes: median=2.0, fibroblasts: median=3.0). Bonferroni correction confirmed zirconia showed the least immune activation (p<0.0167). Zirconia offers superior biocompatibility with minimal immune response, making it an ideal material for orthopedic implants, particularly for patients with metal sensitivities. PEEK showed moderate immune activation but is helpful for non-load-bearing applications. Stainless Steel induced the highest immune response due to the release of metal ions and corrosion. Zirconia is the most biocompatible material tested, making it a promising choice for orthopedic implants.
Staphylococcus aureus is the leading biofilm-forming microorganisms in orthopaedic implant infections. The biofilms formed are difficult to eradicate and resistance to antibiotics. This current study aims to determine the effectiveness of povidone-iodine; an antiseptic solution in eradicating S. aureus biofilm on stainless steel alloy. In addition to the usual Colony-Forming Unit (CFU) used for verification, Scanning Electron Microscope (SEM) is used to validate the formation and eradication of the biofilms. This is an in vitro study where the biofilm is formed by inoculating clinically isolated S. aureus, incubated for 24 hours onto stainless steel alloy 316L implants. The implants are then irrigated using povidone-iodine solution with varying concentrations (5 and 10%) and durations (30, 60, and 180 seconds). The anti-biofilm effect was evaluated using plating and SEM methods to confirm its effectiveness. The process is repeated after 24 hours of post-irrigation reincubation to detect any rebound growth. No biofilm seen after irrigation with povidone-iodine at 5% and 10% concentrations at 30, 60 and 180 seconds, respectively, in both CFU count and SEM. This result is replicated after 24 hours of reincubation, in assessing for rebound growth. Our study supports that a minimum of 5% povidone-iodine with a minimum irrigation time of 30 seconds are effective at eliminating S. aureus biofilm on stainless steel alloy implants. Both CFU count and SEM yield similar value in validating the presence of biofilm. Additionally, SEM allows visualisation of the morphology of the biofilm.
Lithium bis(fluorosulfonyl)imide has emerged as a promising alternative to lithium hexafluorophosphate as conducting salt in battery electrolytes due to its favorable physicochemical properties. However, its tendency to promote the dissolution of Al and stainless steel severely limits its practical application, particularly in lithium ion batteries operating above 4 V vs. Li/Li+. Here we show that the dissolution of SUS316 in lithium bis(fluorosulfonyl)imide-based electrolytes is governed by a synergistic mechanism involving trace Cl- impurities and FSI- anions. Cl- initiates localized pitting, while subsequent interactions between FSI- anions and dissolved iron species lead to the formation of soluble complexes, thereby extending the dissolution process. We further demonstrate that the dissolution can be effectively suppressed by adding lithium difluoro(oxalato) borate. The proposed mechanism involves preferential adsorption of oxalate anions at surface of stainless steel, which limits the access of aggressive anions. Additional improvement is achieved by incorporating more dissolution resistive SUS316L components, resulting in ≈300 cycles until 80 % state of health in silicon-graphite | |LiNi0·8Co0·1Mn0·1O2 cells. Furthermore, this improvement has also been confirmed in silicon-graphite | |LiNi0·8Co0·1Mn0·1O2 pouch cells.
Listeria monocytogenes presents a major challenge in the food industry. Routine monitoring is essential to ensure food safety in processing environments; therefore, rapid and reliable detection of Listeria is crucial for timely and effective intervention. To validate the RapidChek® Listeria NextDay™ Plus test system for the detection of Listeria monocytogenes, Listeria innocua, Listeria seeligeri, Listeria welshimeri, Listeria ivanovii, Listeria marthii and Listeria grayi in selected foods including hot dogs, frozen cooked breaded chicken and vanilla ice cream, and on environmental surfaces, including stainless steel, plastic, rubber, and painted concrete using an unpaired study design. The method uses a proprietary enrichment medium, a 24 to 48 h enrichment at 30 ± 1 °C and detects Listeria spp. on an immunochromatographic lateral flow device within 10 minutes. Listeria inoculated matrices were tested by the method, as well as the cultural reference method. The RapidChek method inclusivity was tested with 51 Listeria strains and its exclusivity using 30 non-target strains. Probability of detection (POD) analysis indicated no significant differences between the candidate method and the cultural reference method in the number of positive test portions detected for hot dogs, frozen cooked breaded chicken, stainless steel, plastic, and painted concrete. For vanilla ice cream and rubber, the candidate method yielded a greater number of positive test portions, with significantly higher POD values at the 95% confidence interval. Following enrichment, the RapidChek assay detected all 51 Listeria strains evaluated and produced no false positives among the 30 non-target organisms tested. The candidate method performed as well as the reference method in the detection of Listeria spp. on environmental surfaces after 24 h of enrichment and in selected food matrices after 27 h of enrichment. Enriching for 24-27 h yielded reliable presumptive results for Listeria spp.
Despite increased interest in virus survival on surfaces, data on bovine herpesvirus type 1 (BoHV-1) interactions with metal surfaces remain limited. This study aimed to assess the effects of copper, zinc, and iron on BoHV-1 viability, viral titre, and DNA stability under different conditions. MDBK-adapted BoHV-1 was used to investigate the virucidal effect of copper, zinc and stainless steel surfaces. The virus was exposed for 1 and 24 h under both wet and dry conditions. Inactivation was assessed based on changes in TCID50 log10 values, qPCR Ct results, and calculating half-lives of the virus and its DNA. Virus stability varied depending on surface type, environmental conditions, and duration of exposure. Copper demonstrated the strongest virucidal effect, significantly reducing viral titres and DNA levels under all conditions. After 1 h in wet conditions, copper reduced viral titre to 4.7 log10, while zinc and stainless steel showed minimal impact. Under dry conditions, copper reduced viral titres to the limit of detection after 24 h. Half-life analysis confirmed rapid inactivation on copper, with the shortest persistence observed across all conditions. Zinc showed moderate virucidal activity but required longer exposure times. These findings highlight copper's superior antiviral properties and suggest its potential application in reducing viral transmission on surfaces.
Long-term osseointegration of orthopedic implants mandates a successful interaction between implant surface and resident bone tissue cells, including osteoblasts and osteoclasts. Titanium, TiAl6V4, and Stainless steel are widely used implant biomaterials due to their high biocompatibility and mechanical strength. In this study, we systematically investigated the effects of polishing and laser-induced periodic surface structures (LIPSS) on osteogenic and osteoclastic differentiation across these materials. A correlative multi-modal approach was employed to capture complementary aspects of bone formation and resorption. Scanning electron microscopy (SEM) assessed cell morphology and extracellular matrix deposition, while energy-dispersive X-ray spectroscopy (EDX) quantified elemental composition associated with mineral deposition. Raman spectroscopy enabled molecular characterization of both mineral (phosphate/carbonate) and organic matrix components. These analyses were complemented by alkaline phosphatase (ALP) activity and osteogenic gene expression to evaluate early and late stages of osteoblast differentiation. In parallel, osteoclast responses were characterized using SEM and F-actin imaging for cytoskeletal organization and fusion, together with tartrate-resistant acid phosphatase (TRAP) activity and osteoclast-related gene expression to quantify osteoclast differentiation. Our results reveal a reciprocal relationship between osteoblast and osteoclast activity for higher laser fluence LIPSS. We demonstrate that laser-modified surfaces support better osseointegration by enhancing bone formation while mitigating bone resorption, with corroborating results from various analytical techniques. These findings suggest that LIPSS is a viable method to optimize implant surfaces for improved osseointegration.
Ultrasonic bulk-wave propagation and detection under cryogenic conditions (77 K) pose significant challenges, as the effects of extremely low temperatures on acoustic coupling and wave behavior remain insufficiently understood. To address this issue, a novel mechanical-electrical-thermal coupling simulation approach is proposed to investigate the propagation characteristics of bulk waves in cryogenic environments. A temperature-dependent electromechanical model of the piezoelectric transducer (PZT) was established, in which the piezoelectric and dielectric properties were implemented as fitted nonlinear functions of temperature to capture the cryogenic response. In addition, a thermo-elastic stress-transfer model of the PZT-adhesive layer-structure system was developed to elucidate the coupling mechanisms induced by temperature-dependent physical properties such as damping and elastic modulus. Based on COMSOL finite element analysis, a fully coupled mechanical-electrical-thermal simulation model was constructed, and the acoustic properties of 316LN stainless steel were obtained within the temperature range of 293 K-77 K and validated through vacuum cryogenic experiments. The results show that at 77 K, the longitudinal-wave amplitude decreases by approximately 60%, while its velocity increases by 97 m/s compared with room temperature. The simulated and experimental data exhibit excellent agreement, with maximum relative deviations of 4.08% in amplitude and 0.34% in velocity, together with a consistently high envelope-based waveform correlation (0.949-0.969) over 77-293 K. The model-experiment agreement was further contextualized by an uncertainty estimate of the velocity measurement and a one-at-a-time sensitivity analysis, supporting the robustness of the proposed coupled model. These findings confirm the accuracy and reliability of the proposed model and demonstrate its potential for ultrasonic nondestructive evaluation of cryogenic components.
Tetracycline (TC) is a commonly prescribed broad-spectrum antibiotic, and its widespread use together with its persistence in biological matrices, particularly urine, has raised serious concerns related to clinical safety, public health and the emergence of antimicrobial resistance, underscoring the need for its accurate and sensitive determination. In this work, an innovative solid-phase microextraction (SPME) strategy was developed for the efficient extraction of TC from human urine samples using polyaniline/phosphotungstic acid/Fe3O4 (PANI/PTA/Fe3O4) nanocomposite coated on stainless-steel substrate. Structural characterization of PANI/PTA/Fe3O4 using field-emission scanning electron microscopy with energy-dispersive, x-ray diffraction (XRD) and Fourier-transform infrared spectroscopy confirmed the successful incorporation of phosphotungstic acid (PTA) and Fe3O4 within the PANI framework. The resulting polymeric coating exhibited a rough and porous morphology, providing numerous active sites for efficient TC adsorption. Key extraction variables, including coating composition, film thickness, solution pH, ionic strength, extraction duration and desorption conditions, were systematically optimized. Under the optimized conditions, the PANI/PTA/Fe3O4 nanocomposite exhibited excellent analytical performance, with a limit of detection of 0.97 ng mL-1, a limit of quantification of 3.24 ng mL-1 and good linearity (R 2 > 0.99) over a wide concentration range. The nanocomposite also exhibited strong reproducibility (intra-day relative standard deviation [RSD] 2.6%-3.9%; inter-day RSD 4.8%-5.0%) and high recoveries in spiked urine samples (99.5%-100.5%). The enhanced sorption performance was attributed to the combined effects of PANI (providing conductivity and π-π/π/hydrogen-bonding interactions), PTA (contributing electrostatic and hydrogen-bonding affinity) and Fe3O4 (imparting magnetic stability and surface activity). Overall, the PANI/PTA/Fe3O4 nanocomposite represents a robust and efficient SPME coating with strong potential for the determination of TC in complex biological matrices. The proposed SPME-high-performance liquid chromatography (HPLC) methodology may be further adapted for the analysis of other structurally analogous antibiotics and pharmaceutical analytes in complex biological matrices by rational tailoring of the coating composition.
Stainless steel (SS) remains widely used in orthopedic implants but is susceptible to corrosion and implant-associated infections in physiological environments. This study aimed to develop a multifunctional multilayer coating combining corrosion resistance, bioactivity, and antimicrobial performance. A ZnO base layer was deposited on 316L SS via pulsed laser deposition, followed by matrix-assisted pulsed laser evaporation of a lovastatin-functionalized bioactive glass (BG57 + LOV) top layer. Two LOV concentrations were initially evaluated, and BG57+0.1LOV was selected based on structural homogeneity, cytocompatibility, and antimicrobial balance. Physicochemical characterization confirmed preservation of chemical integrity and formation of continuous, moderately rough coatings. Electrochemical impedance spectroscopy in simulated body fluid demonstrated progressive improvement in corrosion resistance from bare SS to ZnO-coated and finally to the BG57+0.1LOV/ZnO multilayer, which exhibited the most electropositive corrosion potential and effective suppression of charge-transfer reactions. Biological assays revealed high viability of osteoblasts, fibroblasts, keratinocytes, and macrophages without significant oxidative or nitrosative stress. Antimicrobial testing showed strain-dependent activity, with enhanced efficacy against MRSA and significant reduction in P. aeruginosa, associated with increased ROS/RNS generation. Overall, the BG57+0.1LOV/ZnO system represents a promising multifunctional coating strategy for corrosion-resistant and infection-resistant SS implants.
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This study investigates the cryogenic fracture toughness of four commercially welded 316L stainless steel plates using Charpy-sized single-edge bend [SE(B)] specimens and standard Charpy impact tests, under quasi-static and dynamic loading at 77 K (liquid nitrogen) and 4 K (liquid helium). Despite identical base metal specifications, the welds exhibited substantial variations in mechanical performance due to differences in welding processes and microstructure. The resultant analysis on temperature effects revealed that the only weld fabricated exclusively using gas tungsten arc welding (GTAW) consistently demonstrated the highest fracture toughness by a factor of two at 77 K and a factor of seven at 4 K. In contrast, a welding process that employed flux core arc welding (FCAW) for fill passes that also contained porosity resulted in the lowest overall toughness and greatest degradation (114 kJ/m2 at 77 K and 21 kJ/m2 at 4 K). In an effort to deconvolute the numerous competing mechanisms that contribute to toughness degradation, fractographic analysis revealed that minimal cleavage corresponded with the lowest δ -ferrite content, while the greatest amount of cleavage was linked to wormhole porosity and indicative of embrittlement. When analyzing loading rate effects, Charpy absorbed energy at 77 K broadly correlated with quasi-static toughness at 77 K for only three of the four welds. Dynamic toughness testing at 77 K with the SE(B) geometry and the multi-specimen method correlated poorly with quasi-static results using the SE(B) geometry and the single specimen method to produce J-R curves, but moderately (R2 ≈ 0.76) with Charpy absorbed energy, indicating a stronger dependence on strain rate than intrinsic material toughness. In summary, these findings highlight the critical role of welding process selection, microstructure control, and test methodology in qualifying welds for extreme cryogenic environments and caution against relying solely on Charpy impact testing when atypical weld structures are present.
Particle formation during fill-finish operations poses a critical risk to the quality and manufacturability of high-concentration monoclonal antibody drug products. This study systematically evaluates the influence of pump material, clearance tolerance, and flow-path architecture on subvisible and visible particle generation using a model IgG formulation. Controlled simulations compared peristaltic pumping with ceramic and stainless-steel rotary piston pumps under standstill and recirculation conditions, including a configuration incorporating a three-way valve and deliberate metal particulate spiking. Subvisible particle analysis revealed that particulate generation was dominated by surface-mediated mechanisms: stainless-steel components, tighter (5 µm) pump clearances, and increased flow-path complexity produced the highest particle levels, while ceramic RPPs with moderate clearance generated substantially fewer particulates and avoided pump seizure. Visible particles were observed only in the stainless-steel RPP system containing the three-way valve and metal spiking. Orthogonal characterization (FTIR, Raman, SEM-EDX) confirmed that particulates were primarily proteinaceous and frequently contained embedded metallic inclusions, in the deliberate particulate challenge configuration, consistent with heterogeneous nucleation at high-energy interfaces In contrast, DSC, DSF, MM-IR, DLS-derived kD, and wNMR analyses demonstrated unchanged thermal stability, secondary structure, and protein-protein interaction behavior across all conditions, with no measurable changes in bulk stability metrics across conditions. Mechanistically, the standstill-restart design and orthogonal particle characterization support a surface-mediated pathway in which proteins accumulate at high-energy interfaces during static holds and are subsequently detached under flow, with metal inclusions providing heterogeneous nucleation sites, while bulk IgG stability remains unchanged across conditions. The data support process-development strategies that underscore pump material of contact evaluations, avoid overly tight clearances, reduce recirculation, and simplify valve geometry. This mechanistic-informed framework provides practical guidance for designing robust, patient-centric fill-finish processes aligned with quality-by-design principles. While the study uses a single model IgG1, the observed surface-mediated trends align with broader literature on adsorption-induced particle formation at solid-liquid interfaces.
Acoustic microactuation technology has emerged as an effective approach for fabrication of micro- and nanoscale objects, enabling precise processing and shaping control of microscale materials by efficiently transmitting ultrasonic vibration energy and focusing energy locally. In this work, the proposed platform is regarded as an acoustically driven micromachine, in which ultrasonic excitation acts as the primary microactuation mechanism. Micrometer-scale copper wires are widely used in microelectronics and precision manufacturing. However, their small dimensions and low rigidity make fixation and forming particularly challenging. To achieve controllable forming of fine copper wires, this study introduces an ultrasonic vibration energy-focusing principle and investigates an ultrasonic post-processing method tailored for such materials, with the aim of enhancing processing stability and forming accuracy. An ultrasonic processing experimental platform for copper wires was established, and multiple micro-tool designs-including glass fiber, 304 stainless steel wire with support, and elastic hard 304 stainless steel-were evaluated. Single-point and continuous processing experiments were conducted by varying micro-tool materials and support configurations, and the influence of feed speed on processing width and depth was systematically analyzed. The results indicate that a hard 304 stainless steel micro-tool supported by a hard plastic ring provides the best overall performance. Feed speed has a significant effect on processing depth, with a maximum average depth of approximately 0.95 μm achieved at a feed speed of 1 mm/min. These findings demonstrate the feasibility of ultrasonic processing for the effective forming of fine copper wires and confirm that appropriate micro-tool design and feed speed are critical for achieving stable and reliable processing results. The proposed system employs an ultrasonically actuated micro-tool to perform post-processing on micrometer-scale copper wires. The ultrasonic vibration serves as a microactuation mechanism that enhances local deformation and material response during micro-machining.
To determine whether replacing stainless steel ligature ties during recall visits accelerates anterior tooth alignment (decrowding) in extraction cases. Twenty-four patients with a Little's Irregularity Index (LII) > 4, indicated for bicuspid extraction, were randomly assigned to two groups. All patients received preadjusted edgewise appliances and 0.016 Cu-NiTi initial archwires. Group 1 had ligature ties left in place until alignment completion; Group 2 had ties replaced every 4 weeks. Decrowding was quantified, until the LII score of 0 was achieved, measured at each 4-week interval using digital calipers on study models. Outcome assessors were blinded, and intraobserver and interobserver reliability was established. No significant difference was noted in overall decrowding rate between groups (P = 0.765; Group 1: 68.7 ± 29.0 days; Group 2: 65.3 ± 24.9 days). In Group 2, the maxillary arch showed a faster decrowding rate than the mandibular arch (P = 0.012; 42.0 ± 16.2 vs 77.0 ± 19.8 days). No significant arch difference was found in Group 1. Changing stainless steel ligatures at each recall visit offers no substantial benefit in the overall rate of anterior alignment. Scheduling recall visits every 8 weeks may be recommended for efficient time management during the alignment phase.
The present study aims to compare the gingival health, plaque accumulation, clinical performance and parental satisfaction of stainless steel crowns (SSCs) and fiber-reinforced composite (FRC) crowns in a split-mouth design. Thirty-five children aged 4-7 years requiring full-coverage restorations for both primary mandibular second molars were included. Each child received an SSC and an FRC crown on the contralateral molars. Clinical performance was assessed using the United States Public Health Service (USPHS) criteria, along with the Gingival Index and Plaque Index, at 3, 6, and 9 months. Parental satisfaction was assessed at 9 months. Data were analyzed using paired tests, and survival analysis was performed using the Kaplan-Meier method with the log-rank test. SSCs demonstrated significantly better gingival health and lower plaque scores compared to FRC crowns at all follow-up intervals. Restoration survival was higher for SSCs. Kaplan-Meier survival analysis demonstrated a significantly higher survival probability for SSCs compared to FRC crowns over the 9-month follow-up (p < 0.001). Parental satisfaction scores were higher for SSCs; however, the difference was not statistically significant (p = 0.185). Stainless steel crowns demonstrated better clinical performance and longevity compared to fiber-reinforced composite crowns in primary molars. Although FRC crowns offer improved esthetics, their clinical outcomes were comparatively less favorable over the study period. The findings of this study may help guide clinicians in selecting appropriate full-coverage restorations for primary molars by considering both functional performance and esthetic requirements.
The RapidChek® Listeria monocytogenes NextDay™ Plus Test System was designed to detect Listeria monocytogenes on stainless steel and plastic environmental surfaces and in selected foods. It uses a proprietary enrichment followed by a lateral flow immunoassay to qualitatively detect L. monocytogenes. The aim of this study was to validate the Romer Labs RapidChek® Listeria monocytogenes NextDay™ Plus Test System against the USDA-FSIS-MLG and FDA-BAM cultural reference methods for the detection of L. monocytogenes in select foods including hot dogs, frozen breaded chicken, cured ham, ice cream and cooked shrimp, and on environmental surfaces including stainless steel and plastic (polyurethane, food grade) in an unpaired study design. The RapidChek® method uses a proprietary enrichment media system, a 44 to 48 h enrichment at 30 ± 1 °C and detects L. monocytogenes on an immunochromatographic lateral flow device within 10 minutes. Different L. monocytogenes strains were used to spike each of the matrices. Samples were confirmed based on the reference method confirmations and an alternate confirmation method. There were 82 RapidChek® presumptive positives matrices of which 81 were confirmed by the alternate confirmation method. The respective cultural reference methods produced 74 confirmed positives. All non-spiked samples were negative for Listeria monocytogenes by both methods. Probability of Detection (POD) analysis was performed and found no statistically significant differences between methods. The RapidChek® Listeria monocytogenes NextDay™ Plus Test System demonstrated performance comparable to the respective cultural reference methods while providing rapid results, supporting its use for monitoring L. monocytogenes in food and food processing environments. The method provides the end user with a rapid and reliable tool for monitoring and control of L. monocytogenes in RTE foods and environmental surfaces in accordance with their ongoing food safety needs.
The antimicrobial efficacy and operating parameters of a cold plasma prototype were investigated. The device concept is intended for use on laparoscopic trocar incisions. The device (50 mm length, 10 mm diameter, glass-ceramic body with two wire-wound electrodes) was operated with two gas compositions and in different environments. In vitro decontamination was tested on wet agar plates inoculated with Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) as well as on inoculated stainless steel and polypropylene strips. A 5-min plasma exposure was applied. Both microorganisms were effectively inactivated on wet agar surfaces (inhibition zone assay: up to 36 mm) using different process gas compositions. Additionally, antimicrobial action was confirmed for S. aureus on stainless steel and polypropylene substrates. The prototype thus shows consistent decontamination performance across tested modes. The plasma source offers a promising, minimally invasive adjunct for preventing surgical site infections during laparoscopic procedures. Further development, advanced biological models, and compliance with regulatory standards (e.g., DIN SPEC 91315) are required before clinical implementation.
Residual organic matter on food contact surfaces (FCS) in meat processing plants promotes bacterial attachment and persistence, compromising meat safety and quality. Conventional hot-water cleaning (55-60 °C) can exacerbate this problem by heat-setting proteinaceous residues, leading to the formation of conditioning films that protect microorganisms from subsequent sanitation. A low-temperature, enzyme-based cleaning strategy was specifically designed to disrupt meat-derived residues before thermal fixation occurs, representing a departure from conventional heat-dependent cleaning regimes. A targeted enzyme screening approach was used to identify formulations active at reduced operating temperatures (40-50 °C) and neutral pH, conditions compatible with energy-efficient cleaning-in-place systems. A protease-lipase combination was selected and evaluated on stainless steel and conveyor belt materials contaminated with beef residues. Surface swabbing assays (ATP and protein) quantified the hygienic properties of surfaces post-treatment, showing that the enzyme treatment reduced the frequency of detection of protein on both surface types and reduced ATP levels by approximately 93% on FCS (p < 0.0001). To address microbial persistence beyond residue removal, the formulation was further optimized by incorporating cellulases and an amylase to target extracellular polymeric substances within Escherichia coli O157:H7 biofilms. The enzymatic cocktail reduced biofilm mass significantly (p < 0.0001). There was no statistical difference between negative control wells and enzymatic treatment wells (p = 0.3060), demonstrating near eradication of the biofilm matrix. Enzymatic cleaning regimes show great promise for sustainably enhancing food safety practices in meat processing plants, with lower operating temperatures and more mild solution pH.
Dissimilar welding of titanium alloys to stainless steels offers the potential to combine lightweight, corrosion-resistant titanium with the toughness and cost-effectiveness of steel, yet the formation of brittle Ti-Fe intermetallic compounds (IMCs) at the interface has long prevented its reliable applications. This study examines the role of tantalum interlayer thickness in controlling intermetallic phases evolution and enhancing the mechanical response in pulsed gas tungsten arc welded (P-GTAW) Ti-6Al-4V/SS304 joints. Composite interlayer consisting of Tantalum (Ta) foils of 0.1, 0.3, and 0.5 mm thickness combined with Cu filler was introduced at the interface, and the resulting welds were evaluated through ultimate tensile strength (UTS), microhardness, and detailed microstructural characterization using scanning electron microscopy with energy-dispersive spectroscopy (SEM/EDS) and X-ray diffraction (XRD) supported by fractography analysis. The results demonstrate that increasing interlayer thickness progressively suppressed the formation of Ti-Fe IMCs, refined the fusion zone grain structure, and promoted the development of Cu and Ta based phases. The joints with thickest Ta foil (0.5 mm) depicted high maximum strength (297 MPa), improving by 75% compared to the thinnest interlayer and microhardness profiles becoming smoother across the fusion boundary. These findings confirm that interlayering is an effective method to mitigate brittle phase formation in dissimilar Ti-SS welds. The improvements demonstrated underscore tantalum's potential for aerospace and structural applications are required, where both high strength and reliability are required.