Search Results (87,320)

This study presents a comprehensive characterization of a commercial water-based epoxy primer applied to galvanized steel sheets, which are commonly used in building and construction applications. The investigation focused on evaluating the primer’s adhesion, mechanical strength, chemical resistance, and corrosion protection under various environmental and thermal conditions. Particular attention was given to the effect of substrate sanding prior to application, which was found to influence the coating thickness and surface adaptation. The results demonstrated that the primer provides effective barrier properties and good adhesion to the metal surface, with average pull-off strengths remaining consistent across aged and unaged samples. Electrochemical impedance spectroscopy (EIS) confirmed high polarization resistance values, indicating strong corrosion protection, while SEM-EDS analysis revealed the presence of zinc phosphate and titanium dioxide fillers contributing to both passive and active inhibition mechanisms. However, the primer exhibited sensitivity to ultraviolet (UV) radiation, as evidenced by FT-IR spectra showing increased absorbance in the hydroxyl and carbonyl regions after prolonged exposure. A preliminary estimation of the photodegradation rate, based on FT-IR data at the carbonyl peak (1739 cm⁻¹), yielded a value of approximately 2 × 10⁻⁶ absorbance units per hour between 3000 h and 5000 h of UV exposure. This value suggests a gradual degradation process, although further quantitative validation is required. Additional limitations were observed, including variability in coating thickness due to manual application and localized blistering at cut edges under salt spray conditions. These findings contribute to a deeper understanding of the primer’s behavior and suggest improvements for its practical use, such as the application of a protective topcoat and optimization of the coating process. Full article

Objective: The aim of this study was to evaluate surface roughness (R_a) and microbial adhesion on four provisional prosthodontic materials in comparison to zirconium oxide. Methods: Four provisional prosthodontic restorative materials were evaluated in this study: poly methyl methacrylate (PMMA) acrylic resin (ALIKE; GC America Inc., Alsip, IL, USA), dimethacrylate (Bis-acryl) resin (Integrity; Dentsply Sirona, Charlotte, NC, USA), 3D-printed temporary crown and bridge resin (Formlabs; Inc, Somerville, MA, USA), prepolymerized poly methyl methacrylate (milled PMMA) (Harvest Dental Laboratory Products, Brea, CA, USA), and zirconium oxide (Ivoclar Vivadent AG, Liechtenstein, Germany). A total of 90 samples were prepared and divided into two groups per material (treated and untreated). Provisional material samples were prepared per manufacturer’s instructions, polished with the same sequence using acrylic burs followed by Acrylipro silicone polishers (Brasseler, Savannah, GA,USA), and pumice with a goat brush. Zirconia was polished with a green grinding stone (ZR Grinders; Brassseler, Savannah, GA, USA), followed by a feather lite (Dialite ZR polisher; Brasseler, Savannah, GA, USA). The Ra of all samples was measured using a digital profilometer. Sterilized samples were incubated in Todd Hewitt yeast extract (THY) broth containing Candida albicans SC5314 and Streptococcus mutans BM71 at 37 °C under anaerobic conditions for 72 hours. Subsequently, the number of colony-forming units (CFU) adhered to each sample was determined by serial dilution plating. Normality and homoscedasticity were assessed prior to statistical analysis. Welch’s ANOVA was then performed to evaluate differences among all samples, followed by Games–Howell post hoc tests for pairwise comparisons. A p < 0.05 was considered significant in all experiments. Results: Zirconia demonstrated the lowest surface roughness and significantly reduced adhesion of S. mutans and C. albicans compared to all other materials (p < 0.001). Milled PMMA exhibited significantly lower roughness and microbial adhesion than conventional PMMA (p < 0.001), with no significant difference from Printed PMMA in microbial adhesion. Additional pairwise differences were observed between Bis-acryl and PMMA (p = 0.0425), Milled and Printed PMMA (p < 0.0001), and Bis-acryl and Printed PMMA (p < 0.0001). Conclusions: Zirconia and milled PMMA showed superior surface properties and reduced microbial adhesion, supporting their use in long-term provisional restorations. Materials with higher microbial retention, such as self-curing PMMA, bis-acryl, and 3D-printed resins, may be less suitable for extended use. These findings guide material selection to improve clinical outcomes and highlight the need for further in vivo research. Full article

Background: Glioma remains an intractable and highly aggressive brain tumor, mainly due to the daunting obstacle presented by the blood–brain barrier (BBB). To overcome this challenge and enhance therapeutic efficacy, a dual-drug delivery system was engineered. This system co-encapsulated curcumin, a nutraceutical with multitargeted anticancer potential, with atorvastatin calcium, a repurposed anticancer agent, within lipidic nanocapsules (LNCs). Methods: LNCs were prepared via the phase inversion temperature method and optimized using a Box–Behnken design. The optimized LNCs were subsequently functionalized with folic acid (FA) to enable active targeting. FA-LNCs were characterized using XPS, TEM, in vitro release, and MTT cytotoxicity assays. Atorvastatin and curcumin were radiolabeled separately with iodine-131 to evaluate the in vivo pharmacokinetics in a glioma-bearing mouse model. Results: The optimized LNCs and FA-LNCs displayed a mean particle size of 97.98 ± 2.27 nm and 181.60 ± 2.83 nm, a polydispersity index of 0.32 ± 0.07 and 0.40 ± 0.02, and a zeta potential of −15.85 ± 1.35 mV and −11.90 ± 2.80, respectively. XPS and FTIR analyses verified FA conjugation. Both LNCs and FA-LNCs enhanced the in vitro cytotoxicity compared to free drugs; however, the most pronounced effect of FA functionalization was observed in vivo. Most significantly, FA-LNCs achieved markedly greater glioma accumulation than non-functionalized LNCs, with AUC values 2.0-fold higher for atorvastatin and 2.6-fold higher for curcumin. When compared to the free drug solutions, this efficiency was even more pronounced, with atorvastatin and curcumin showing enhancements of 8.2 and 12.4 times, respectively. Conclusions: FA-LNCs markedly improved glioma targeting efficiency and reduced systemic clearance, which underscores the therapeutic potential of integrating nutraceuticals with repurposed agents to achieve effective glioma therapy. Full article

Background: Natural compounds such as fisetin have promising in breast cancer treatment, but their poor pharmacokinetics limit their therapeutic application. This study utilized a synergistic approach by combining fisetin-loaded Nigella sativa (N.S.) oil nanovesicles (FIS-NSs) and carbohydrate-based microneedles (FIS-NSs-MNs) to improve breast cancer management. Methods: Chemical composition of NS petroleum ether extract using gas chromatography–mass spectrometry (GC/MS). FIS-NSs were prepared and characterized for particle size, polydispersity, zeta potential, encapsulation efficiency, and stability. These vesicles were embedded into gelatin, hyaluronic acid, and carboxymethyl cellulose microneedles. In vitro drug release, ex vivo permeation, cytotoxicity against breast cancer cells, and in vivo antitumor efficacy in Ehrlich tumor models were evaluated. Results: Optimized FIS-NSs displayed nanoscale size (190 ± 0.74 nm), low P.D.I (0.25 ± 0.07), high surface charge (+37 ± 0.57 mV), and high encapsulation (88 ± 0.77%). In vitro investigations showed sustained FIS release (~85% over 72 h), while ex vivo permeation showed higher absorption than free fisetin. Both FIS-NSs and FIS-NSs-MNs showed dose-dependent cytotoxicity against breast cancer cells, with lower IC₅₀ than free fisetin (24.7 µM). In vivo, FIS-NSs-MNs and tumor burden inhibition (~77%), reduced oxidative stress (54%), restored antioxidant defenses, and decreased inflammatory markers. Immunohistochemical analysis for caspase-3 showed apoptosis activation within tumor tissues. Conclusions: These findings demonstrate that FIS administration via NS-MNs improves drug stability, penetration, and apoptotic activity, resulting in enhanced anticancer effects. This innovative nanovesicle–microneedle platform provides a non-invasive, effective, and patient-friendly approach for the effective treatment of breast cancer, with potential for broader applications in oncological nanomedicine. Full article

As key intermediate products in petroleum and chemical units, C4 hydrocarbons can be converted to ethene and propylene. While C4 olefins can be cracked into ethene and propylene on acid catalysts, such reactions with C4 paraffins are difficult under these conditions. In this study, a bifunctional metal–acid catalyst, BDHC, was prepared for catalytic dehydrogenation and catalytic cracking, using ZSM-5 zeolite for cracking active groups and Fe₂O₃ and Cr₂O₃ for dehydrogenation active groups. In the catalyzed reaction, C4 paraffins are converted to C4 olefins, which are subsequently cracked into ethene and propylene. The BDHC catalyst’s high relative crystallinity and large specific surface area and pore volume promote adsorption of reactant molecules. Moreover, the appropriate acid content suppresses side pathways and produces more ethene and propylene. Under optimized conditions, the ethene yield was 11.20%, the propylene yield was 27.51%, and the sum of the ethene and propylene yields was 38.71%. Full article

Organic–inorganic metal halides (OIMHs) have emerged as highly promising semiconductor materials owing to their outstanding optoelectronic properties. Incorporation of chiral organic molecules into the metal–halide framework enables the construction of chiral OIMHs, which exhibit unique chiroptical phenomena in addition to the intrinsic advantages of perovskite-based semiconductors. This review provides a systematic overview of recent progress in chiral OIMHs, covering synthetic approaches, crystal structures, mechanisms of chirality transfer, circularly polarized luminescence, and circularly polarized light detection. We further highlight the current challenges and outline future research directions, emphasizing the need for strategies that enhance chiroptical responses, stability, and device integration. By bridging fundamental insights with design principles, this work aims to guide the rational development of next-generation chiral functional materials for advanced optoelectronic and spintronic applications. Full article

Background: The new challenges facing the healthcare sector require nursing leaders who are prepared to respond to patients’ healthcare needs and keep professionals motivated and satisfied while meeting the organisation’s objectives. To overcome these challenges, interest has grown in positive leadership styles, which in turn has sparked interest in authentic leadership. This line of thought on leadership has been predictive of various positive outcomes in the hospital context. Objective: Examine the characteristics of authentic leadership among nurses in the hospital context based on scientific evidence. Methods: Scoping review according to the Joanna Briggs Institute, consisting of three stages of research. First, a search was conducted in MEDLINE Ultimate, CINHAL Ultimate and MedicLatina through the EBSCOHost platform, LILACS and RCAAP for grey literature. Then, using the same keywords, we conducted a search in Scopus and ScienceDirect. Both searches covered the period between 2019 and 2024. Studies were included if they focused on authentic leadership in nurses working in hospital contexts; non-empirical studies, reviews, and those outside the nursing field were excluded. Results: Sixteen articles were included, 13 of which were cross-sectional, descriptive and/or correlational, 2 were quasi-experimental and 1 employed an exploratory and confirmatory factor analysis approach. The Authentic Leadership Questionnaire was used in a total of 11 articles. The studies showed that authentic leadership by nurses in a hospital context is significantly associated with relevant organisational and individual variables, such as team performance, organisational commitment, job satisfaction, reduced burnout, and the promotion of healthy work environments. The data also revealed discrepancies between the perceptions of leaders and their subordinates. Conclusion: Authentic leaders have a positive impact on the quality of nursing care, patient health outcomes, professional satisfaction and motivation to lead and the achievement of healthcare institution goals. Consequently, authentic leadership is a fundamental pillar for strengthening nursing teams, promoting trust, well-being and improvements in the quality of care. Nevertheless, the strength of the evidence is limited, given the predominance of cross-sectional studies and potential contextual biases, which should be considered when interpreting the findings. Full article

The high-efficiency and clean utilization of coal resources is a key strategy for new energy development, and converting coal into carbon materials offers a promising route to valorize bituminous coal. However, fabricating high-performance bituminous coal-derived carbon for sodium ion (Na⁺) insertion/extraction remains a major challenge, as it is difficult to regulate the carbon’s microstructural properties to match Na⁺ storage demands. Herein, we propose a molten salt-assisted carbonization strategy to prepare bituminous coal-derived hard carbon (HC) for use as a sodium-ion battery (SIB) anode material, and we focus on regulating the structure of carbon. The results show that as-prepared HC exhibits significantly enhanced electrochemical performance for Na⁺ storage when the molar ratio of NaCl to KCl is 1:1. The optimized material achieves a reversible capacity of 366.7 mAh g⁻¹ at the current density of 100 mA g⁻¹ after 60 cycles and retains 99% of its initial capacity after 500 cycles at a current density of 1 A g⁻¹. The main finding is that the lattice spacing can be regulated by tuning the composition of the molten salt, and anode performance is enhanced remarkably by changes in the HC structure. This work provides a feasible strategy for designing and preparing a bituminous coal-derived carbon anode material for use in the energy storage field. Full article

Background: An unhealthy diet is a major modifiable risk factor for chronic disease, and workplace environments may pose specific barriers to healthy eating. Methods: This single-arm, pre–post workplace intervention assessed short-term changes in perceived dietary barriers (primary outcome) and healthy eating intentions (secondary outcome) among school employees (n = 36; 83.3% women; mean age = 46.8 years). The 60 min participatory session integrated behavioral economics principles, practical nutrition exercises, and psychological strategies designed to enhance self-efficacy, optimism, and resilience. Results: The total perceived barrier score decreased significantly (Δ = −1 [IQR −2 to 0]; the paired Wilcoxon signed-rank test = −4.689, p < 0.001, r = −0.78). Post-intervention (T2), the proportion of participants reporting an intention to prepare healthy meals increased (McNemar’s test, p < 0.001; OR = 10.0, 95% CI 1.8–54.5). The session was rated as highly useful (mean = 8.3/10), and at the three-week follow-up (T3), 91.7% of participants reported maintaining at least one dietary change. Conclusions: Although limited by its single-arm design and short follow-up, this pilot study suggests that a brief, participatory behavioral intervention may be a feasible and acceptable approach to support healthier eating in the workplace. Full article

Heavy metal ions (HMIs) threaten ecosystems and human health due to their carcinogenicity, bioaccumulativity, and persistence, demanding highly sensitive, low-cost real-time detection. Electrochemical sensing technology has gained significant attention owing to its rapid response, high sensitivity, and low cost. Molybdenum disulfide (MoS₂), with its layered structure, tunable bandgap, and abundant edge active sites, demonstrates significant potential in the electrochemical detection of heavy metals. This review systematically summarizes the crystal structure characteristics of MoS₂, various preparation strategies, and their mechanisms for regulating electrochemical sensing performance. It particularly explores the cooperative effects of MoS₂ composites with other materials, which effectively enhance the sensitivity, selectivity, and detection limits of electrochemical sensors. Although MoS₂-based materials have made significant progress in theoretical and applied research, practical challenges remain, including fabrication process optimization, interference from complex-matrix ions, slow trace-metal enrichment kinetics, and stability issues in flexible devices. Future work should focus on developing efficient, low-cost synthesis methods, enhancing interference resistance through microfluidic and biomimetic recognition technologies, optimizing composite designs, resolving interfacial reaction dynamics via in situ characterization, and establishing structure–property relationship models using machine learning, ultimately promoting practical applications in environmental monitoring, food safety, and biomedical fields. Full article

An investigation was carried out to improve the gamma radiation shielding properties of Benecel K4M pharmaceutical polymer using zinc oxide (ZnO) at concentrations from 0 to 6 wt.%. Compressed composite tablet samples were prepared and tested in the range of photon energies 59.5 to 1332 keV for the assessment of various shielding parameters, including linear attenuation coefficient, radiation protection efficiency (RPE), and mean free path (MFP). As the ZnO content increased, the attenuation properties of the material showed improved shielding behavior, which was attributed to its high density and atomic number. At 59.9 keV, RPE increased from 6.9% for the pure polymer to 12.2% for the 6 wt.% composite, whereas MFP decreased from 13.9 cm to 7.6 cm. The results indicate that ZnO addition significantly enhances the shielding efficiency of Benecel K4M, demonstrating that ZnO can serve as a lightweight and non-toxic alternative to heavy-metal-based materials for pharmaceutical protection in radiation-rich environments. Full article

Silica aerogel has garnered significant attention in the biomedical field, primarily due to its unique combination of a three-dimensional structure, low density, tunable nanoscale pores, and an extensive surface area. These intrinsic properties render it as an exceptional candidate for advanced drug delivery systems (DDSs). In the realm of medical applications, silica aerogels have demonstrated remarkable potential, especially in nanoscale DDSs. Traditional drug delivery methods, such as capsules and tablets, are often plagued by several drawbacks, including poor bioavailability, lack of target specificity, and multidrug resistance. These limitations necessitate the development of more efficient and targeted drug delivery systems. Recent advancements in the synthesis and modification of silica aerogels have significantly enhanced their biocompatibility and functionalization capabilities. These improvements have further bolstered their potential for controlled release and targeted delivery of therapeutic agents. This study is based on silica aerogel-based nanocarrier systems, providing an in-depth exploration of its fundamental principles, preparation processes, and recent advancements. Based on this, we summarize the drug delivery methods, drug release characteristics, and diverse medical applications of silica aerogels. Additionally, we discuss the challenges and future prospects of applying silica aerogels in drug delivery systems, aiming to provide a comprehensive overview of this field. Full article

The effects of free radicals and chronic oxidative stress are the cause of many diseases, including those of the oral cavity, among which the most important are inflammatory processes and cancer. For this reason, an important element of the body’s defense is maintaining proper antioxidant activity. Study aim: To assess oxidative stress parameters in the saliva of patients using removable prostheses after head and neck cancer surgery. Material and methods: 44 oncological patients operated on for head and neck cancer and 20 healthy edentulous volunteers as a control group. Removable acrylic dentures were prepared for both groups. The material for oxidative stress analysis was saliva: non-stimulated saliva (NWS) and stimulated saliva (SW) after 3 months of prosthetic treatment. Results: Changes in the level of oxidative stress parameters were observed in the study group after 3 months of prosthetic treatment. Specifically, we observed a higher level of deoxyribonucleic acid (DNA)/ribonucleic acid (RNA) damage in oncology patients compared to controls. The levels of protein oxidation products—protein carbonyls, lipid peroxidation products, malondialdehyde (MDA), and nitrotyrosine—were slightly higher in the study group in all measurements. Conclusion: Based on this study, it was found that removable prostheses have a minor impact on the level of enzymatic and non-enzymatic oxidative stress parameters. This research suggests an adaptation to prosthetic restorations that results in almost restored redox balance. Full article

To address the issues of insufficient capacity and difficult regeneration of adsorbents for phosphate removal from wastewater, in this study, FeOOH/Al₂O₃ adsorbents were successfully developed by in situ growing amorphous iron oxyhydroxide (FeOOH) within the pores of alumina (Al₂O₃) using a simple method. The physicochemical properties of FeOOH/Al₂O₃ adsorbents were characterized using X-ray Diffraction (XRD), N₂ adsorption/desorption analysis, and scanning electron microscopy (SEM). Additionally, their phosphate adsorption properties were comparatively investigated. The results revealed that FO-A-3, one of the FeOOH/Al₂O₃ samples prepared with Fe/Al molar ratio of 0.47, exhibited excellent adsorption capacity and a relatively fast adsorption rate, surpassing those of Al₂O₃ and amorphous FeOOH alone. The adsorption process of phosphate using FO-A-3 conformed to the pseudo-second-order kinetic model and the Langmuir isotherm model, with a maximum adsorption capacity of 131.00 mg/g. To tackle the problem of poor regeneration performance, this study innovatively proposed a repeatable and simple regeneration strategy. Experiments demonstrated that FO-A-3 maintained a relatively high adsorption capacity after four cycles of regeneration. Full article

Multiparty quantum private comparison (MQPC) aims to determine the equality relationship of inputs from multiple participants while maintaining the confidentiality of these inputs. Current MQPC protocols primarily focus on utilizing d-level quantum states, which limits feasible implementation. To address this issue, we introduce an MQPC protocol that utilizes n-particle Greenberger–Horne–Zeilinger (GHZ) state to enable private comparison while preserving the secrecy of individual inputs. A semi-honest third party (TP), adhering to protocol specifications but potentially curious about private data, generates and distributes GHZ state qubits to all participants. Each party encodes their secret input through rotation operations on their allocated qubits and returns the modified state to the TP, which then performs single-particle quantum measurements to derive the outcomes without accessing the raw inputs. The protocol’s sequence distribution method yields a high qubit efficiency of 1/n, outperforming many existing MQPC protocols. Security analysis confirms resilience against external adversaries employing quantum attack strategies and collusion attempts among participants. Simulations using IBM Qiskit validate the feasibility of the protocol, which relies on GHZ state preparation, single-qubit operations, and single-particle quantum measurements. Full article