Search Results (16,580)

Breast cancer (BC) remains a leading cause of cancer-related mortality in women. Extracellular matrix (ECM) remodeling is a critical modulator of tumor invasion and metastasis. Three-dimensional (3D) cell culture models have been proposed as advanced systems better mimicking the tumor microenvironment (TME), potentially offering enhanced insights into underlying mechanisms compared to conventional two-dimensional (2D) cultures. This study highlights how BC cells develop metastatic potential and tumor progression independently from ECM contact using advanced 3D spheroid culture models compared to traditional 2D cultures in triple-negative breast cancer (TNBC) cell lines. Spheroids were formed using ultra-low adhesion plates, and their morphological and functional properties were assessed via phase-contrast and scanning electron microscopy (SEM), along with functional assays. Both cell lines formed compact spheroids exhibiting mesenchymal-to-epithelial transition (MET) characteristics. Functional assays showed enhanced cell migration and dissemination of spheroid-derived cancer cells. Gene expression profiling revealed increased expression of ECM remodeling enzymes, cell surface receptors, and adhesion molecules in 3D cultures compared to 2D. MicroRNA analysis highlighted distinct regulatory patterns specifically associated with metastasis and epithelial-to-mesenchymal transition (EMT). These findings demonstrate that 3D spheroid models effectively recapitulate the complexity of TNBC, providing valuable insights into ECM dynamics, epigenetic regulation, and metastatic behavior and potentially guiding improved therapeutic strategies. Full article

Klebsiella pneumoniae is the second-most common opportunistic pathogen in clinical practice and has developed resistance to potent antibacterial drugs such as carbapenems. Therefore, developing safe and effective strategies for the prevention and treatment of K. pneumoniae infections remains a critical challenge. In this study, a strain named Tie-10 isolated from Antarctic samples demonstrated potent antibacterial activity against K. pneumoniae, which was subsequently identified as Bacillus nakamurai. The fermentation medium and culture conditions were systematically optimized through single-factor experiments, orthogonal array testing, and response surface methodology. The optimal medium composition was determined to be beef extract, peptone, and KNO₃. The culture conditions included a time of 24 h, temperature of 37 °C, pH of 7.0, and bottling volume of 80 mL. Antagonistic experiments demonstrated that the crude extract of B. nakamurai Tie-10 exhibited significant inhibitory activity against K. pneumoniae. The alkaline protease (AKP) assay demonstrated that the crude extract effectively disrupted the cellular integrity of K. pneumoniae, a finding further corroborated by scanning electron microscopy (SEM) analysis. Furthermore, the crude extract significantly inhibited extracellular protease secretion in K. pneumoniae, downregulated the expression of virulence-associated genes, and effectively disrupted biofilm formation. The study presented innovative strategies for the management and containment of K. pneumoniae infections. Full article

In this work, a rapid process optimization framework for laser powder bed fusion (LPBF) based on a high-throughput mechanical testing platform and data analytical methods was proposed and validated. This framework enables the efficient building of a process–properties database and analytical model, as well as the fine-tuning of customized mechanical properties. Unlike previous approaches that focused primarily on density as the main optimization target, this method directly aligns the mechanical properties by systematically varying the LPBF process parameters (e.g., laser power, scanning speed, etc.). Tensile specimens in the high densification range were prepared and tested using a high-throughput mechanical property test platform (HTP). Following this, an analytical model correlating tensile properties and process parameters was developed using response surface methodology (RSM). Based on this model recommendation, a specimen with a densification of 99.46% and a yield strength (YS) of 524.74 MPa was achieved, with only a 3.72% variation compared to the predicted value (526.08 MPa), confirming the model’s reliability. A comprehensive analysis of relative density, phase content and microstructure was conducted, comparing them with a specimen exhibiting lower properties. This study provides an effective method for the rapid evaluation and optimization of LPBF processing parameters for fine-tuning customized mechanical properties. Full article

Two proline-rich antimicrobial peptides (PrAMPs), named P1 and P2, purified from hemolymph of the greater wax moth Galleria mellonella, were studied for their effects on Gram-negative (Escherichia coli) and Gram-positive (Micrococcus luteus) bacteria. Both peptides decreased the M. luteus bacterial survival rate and caused E. coli bacterial membrane permeabilization. However, in both cases, the P2 peptide was approximately three times more effective than the P1 peptide. Fluorescence microscopy imaging demonstrated binding of both FITC-labeled peptides to E. coli and M. luteus cells. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) imaging of peptide-treated bacteria revealed considerable changes in cell morphology, cell surface topography, and nanomechanical properties. The interactions of the PrAMPs with bacterial cells were also analyzed by FTIR spectroscopy. The P1 peptide action toward E. coli led to partial aggregation of proteins, whereas treatment with P2 resulted in reduced protein aggregation, reflecting differences between both G. mellonella PrAMPs antibacterial action. Moreover, both PrAMPs caused a decrease and an increase in the protein content in relation to lipids on the E. coli and M. luteus cell surface, respectively. The obtained results reflect not only differences between the G. mellonella P1 and P2 peptides but also differences in the cell surface between Gram-negative and Gram-positive bacteria. Both characterized G. mellonella PrAMPs are further representatives of proline-rich peptides with a membrane-permeabilizing antimicrobial mode of action. Full article

Zinc-based alloys have been extensively studied for their potential applications in biodegradable materials, yet their corrosion behaviour necessitates the development of effective surface treatments. In this study, a ZnMg alloy was developed by casting in an inert medium and subsequently treating it with Plasma Electrolytic Oxidation (PEO). The corrosion behaviour was characterised in a 0.9% NaCl solution through Tafel polarisation, cyclic polarisation, and electrochemical impedance spectroscopy (EIS). Additionally, the surface morphology was investigated using scanning electron microscopy (SEM) and EDX analysis. The structure and phases of the oxide layer and of the corrosion products were investigated through X-ray diffraction (XRD). The electrochemical results demonstrated a substantial decrease in the corrosion current density and an increase in the polarisation resistance for the treated samples. Electrical Impedance Spectroscopy (EIS) modelling revealed the formation of a layer exhibiting distinct capacitive behaviour, comprising two distinct regions. XRD analysis confirmed evidence of corrosion compounds characteristic of chlorinated media on the surface. The findings indicated that PEO treatment enhanced the corrosion resistance of the ZnMg alloy, suggesting its suitability for biomedical applications or exposure to marine environments characterised by high levels of corrosion. Full article

The aim of this study is to evaluate the effect of various lubrication systems (dry cutting, MQL, and nano-MQL) on the machinability of AISI 1040 medium-carbon steel. By dispersing titanium carbide (TiC) nanoparticles into environmentally friendly sunflower oil, a new type of nano-MQL fluid was developed. Machinability parameters such as surface finish, cutting force, energy consumption, chip structure, and tool degradation were examined through scanning electron microscopy (SEM). Based on experimental observations, the use of the nano-MQL technique led to a notable enhancement in machining performance when compared to both dry and traditional MQL machining. In addition, surface roughness was substantially reduced with the nano-MQL, suggesting more effective lubrication and cooling. Reductions in cutting forces and energy consumption were also observed, indicating more efficient material removal and lower mechanical resistance. The SEM examination of the cutting tools proved the low wear rate of the nano-MQL, which exhibited less adhesion and more abrasion wear, and of dry cutting, which showed the most serious wear. Furthermore, chip morphology illustrations indicated that the chips of nano-MQL were relatively uniform and segmented, indicating superior chip breaking quality and cutting stability. The results suggest that employing TiC nanoparticles in MQL offers a clear enhancement of cutting performance in terms of process efficiency, surface quality, and tool wear. These results validate the capability of nano-MQL as an environmentally friendly and high-performance lubrication method for turning medium-carbon steels, supporting more sustainable and efficient manufacturing operations. Full article

In the search for lightweight and sustainable engineering approaches, enhancing the surface wear resistance of structural materials, such as 6061-T6 aluminum alloy, has become increasingly important. This study investigates the effect of coverage rates on the tribological properties of shot-peened 6061-T6 alloy, aiming to improve its usage in industries where weight reduction and durability are important, such as aerospace, automotive, railway, and renewable energy systems. A shot peening process was applied at four different coverage rates of 100%, 200%, 500%, and 1500% for comprehensive evaluation. A series of experimental analyses were conducted, including microhardness tests, ball-on-plate wear tests, residual stress measurements, and surface roughness evaluations. Furthermore, microstructural analysis was performed to investigate subsurface deformation, and scanning electron microscopy (SEM) was carried out to identify the wear mechanisms of the worn surfaces in detail. The results demonstrated a clear trend of gradual improvement in wear resistance with increasing shot peen coverage. The sample treated at a 1500% coverage rate exhibited 1.34 times higher hardness and 19 times higher wear resistance compared to the untreated sample. This study highlights that shot peening is an effective and feasible surface engineering method for enhancing the wear performance of 6061-T6 alloy. The findings offer valuable contributions for the development of lightweight and wear-resistant components considering sustainable material design. Full article

Instrument fracture during endodontic treatment significantly compromises treatment outcomes, with sodium hypochlorite (NaOCl) and other irrigants potentially affecting the cyclic fatigue resistance of nickel–titanium (NiTi) rotary files. This systematic review evaluated the impact of endodontic irrigants on NiTi instrument durability. A comprehensive literature search was conducted across PubMed, Scopus, Web of Science, Embase, Cochrane Library, and WorldCat databases through June 2025, following PRISMA guidelines. Studies investigating cyclic fatigue resistance of NiTi rotary instruments exposed to various irrigants were included. Twenty-seven in vitro studies met the inclusion criteria, involving instruments across multiple file systems and irrigant solutions. The review revealed that NaOCl, particularly at concentrations ≥5% and elevated temperatures, significantly reduced cyclic fatigue resistance in most studies, with scanning electron microscopy confirming surface corrosion and microcrack formation. Heat-treated NiTi alloys demonstrated superior fatigue resistance compared to conventional austenitic alloys. Short-term NaOCl exposure (1–5 min) showed minimal impact, while prolonged exposure combined with autoclave sterilization produced cumulative weakening effects. Alternative irrigants such as EDTA and chlorhexidine showed more neutral effects on instrument integrity. These findings suggest that irrigant selection and exposure protocols significantly influence NiTi instrument longevity, with implications for clinical endodontic practice and instrument safety protocols. Full article

Natural materials present sustainable opportunities in architectural design, but often lack the aesthetic controllability associated with synthetic alternatives. This research explores the bio-aesthetic potential of mycelium-bound composites (MBCs) cultivated from Ganoderma Steyaertanum (Reishi mushroom), focusing on how external stimuli and surface treatments influence material expression. This investigation was carried out through interdisciplinary collaboration involving design, architecture, and material science. Two post-demolding surface treatment strategies were applied to MBC samples: ‘Delayed Growth‘ and ‘Accelerated Growth‘. These treatments were designed to assess the mycelium’s responsiveness in terms of colour and texture development. A controlled set of samples was analysed using scanning electron microscopy, Fourier-transform infrared spectroscopy, and hydrophobicity testing to evaluate changes in microstructure, chemical composition, and surface properties. The results demonstrate that mycelium exhibits a measurable capacity for aesthetic adaptation, with distinct variations in pigmentation and texture emerging under different treatment conditions. These findings highlight the potential for co-creative design processes with living materials and offer new insights into the integration of biological responsiveness in design practices. The study contributes to the advancement of sustainable material systems and expands the possibilities for bio-design through controlled interaction with bio-materials. Full article

Background: One of the most widely used metal nanoparticles in biological applications is gold, which has unique physicochemical characteristics. Strong localized surface plasmon resonance (LSPR) endows them with exceptional optical properties that facilitate the development of innovative methods for biosensing, bioimaging, and cancer research, particularly in the context of photothermal and photodynamic therapy. Methods: This study marked the first time that Mandragora autumnalis ethanolic extract (MAE) was utilized in the environmentally friendly synthesis of gold nanoparticles (AuNPs). Several characterization methods, including dynamic light scattering analysis (DLS), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and biological methods, were used to emphasize the anti-cancerous activity of the biogenic AuNPs. Results: MAE-AuNPs showed a surface plasmon resonance band at 570 nm. DLS and SEM demonstrated the synthesis of small, spherical AuNPs with a zeta potential of −19.07 mV. The crystalline nature of the AuNPs was confirmed by the XRD pattern, and data from FTIR and TGA verified that MAE-AuNPs played a part in stabilizing and capping the produced AuNPs. In addition, the MAE-AuNPs demonstrated their potential effectiveness as antioxidant and anticancer therapeutic agents by demonstrating radical scavenging activity and anticancer activity against a number of human cancer cell lines, specifically triple-negative breast cancer cells. Conclusions: Green synthesis techniques are superior to other synthesis methods because they are simple, economical, energy-efficient, and biocompatible, which reduces the need for hazardous chemicals in the reduction process. This article highlights the significance of characterizing MAE-AuNPs and evaluating their antioxidant and anticancer properties. Full article

Digital dentistry is undergoing rapid evolution, with three-dimensional imaging technologies increasingly integrated into routine clinical workflows. Originally developed for accurate dental arch reconstruction, modern intraoral scanners have demonstrated expanding versatility in capturing intraoral mucosal as well as perioral cutaneous structures. Concurrently, photogrammetry has emerged as a powerful method for full-face digital reconstruction, particularly valuable in orthodontic and prosthodontic treatment planning. These advances offer promising applications in forensic sciences, where high-resolution, three-dimensional documentation of anatomical details such as palatal rugae, lip prints, and bite marks can provide objective and enduring records for legal and investigative purposes. This study explores the forensic potential of two digital acquisition techniques by presenting two cadaveric cases of animal bite injuries. In the first case, an intraoral scanner (Dexis 3600) was used in an unconventional extraoral application to directly scan skin lesions. In the second case, photogrammetry was employed using a digital single-lens reflex (DSLR) camera and Agisoft Metashape, with standardized lighting and metric scale references to generate accurate 3D models. Both methods produced analyzable digital reconstructions suitable for forensic archiving. The intraoral scanner yielded dimensionally accurate models, with strong agreement with manual measurements, though limited by difficulties in capturing complex surface morphology. Photogrammetry, meanwhile, allowed for broader contextual reconstruction with high texture fidelity, albeit requiring more extensive processing and scale calibration. A notable advantage common to both techniques is the avoidance of physical contact and impression materials, which can compress and distort soft tissues, an especially relevant concern when documenting transient evidence like bite marks. These results suggest that both technologies, despite their different origins and operational workflows, can contribute meaningfully to forensic documentation of bite-related injuries. While constrained by the exploratory nature and small sample size of this study, the findings support the viability of digitized, non-destructive evidence preservation. Future perspectives may include the integration of artificial intelligence to assist with morphological matching and the establishment of digital forensic databases for pattern comparison and expert review. Full article

Background: Accurate facial proportion analysis is essential for therapeutic planning in dentistry. This study aimed to evaluate the Planmeca ProFace 3D scanner’s accuracy by comparing its digital measurements to analog caliper measurements. Methods: A comparative cross-sectional study included seven patients. Fourteen standardized facial landmarks were measured digitally and with an analog caliper. Distances were grouped as small (≤6.5 cm, Group A) or large (>6.5 cm, Group B). Paired t-tests, Cronbach’s Alpha, and Bland–Altman analysis assessed differences, reliability, and agreement. Results: The results showed a statistically significant difference between the two methods of measurements in group A (p = 0.016) and high statistical significance was obtained in group B (p = 0.001). Cronbach’s Alpha showed high reliability for Group A (α = 0.982) but low for Group B (α = 0.270). The mean difference between the caliper and software measurements was 0.24 ± 0.9 SD (min 0.16 max 2.92) in group A and 0.71 ± 2.8 SD (min 0.02 max 4.17). Bland–Altman analysis revealed a consistent positive proportional bias, with differences increasing for larger measurements. Conclusions: Facial point measurements by the means of digital scanning technique show measurements overlapping with analog technique for measurements less than or equal to 6.5 cm, with significant deviation for points with a distance greater than 6.5 cm. A hybrid approach or compensatory strategies are needed to ensure clinical precision. Full article

The article presents the results of original research on determining the abrasive properties of composite materials with an epoxy resin matrix reinforced with basalt particles in the form of powder and pine chips from the post-production waste of wooden elements. There are many studies available in the literature on the modification of composite materials in terms of achieving the required strength properties, but there is little information available in the area of achieving specific functional properties of composite materials, e.g., abrasive properties. Three composite materials with different proportions of the material components were made. These materials were tested using standardized tests to determine their mechanical properties, and these properties were compared in relation to the matrix material (epoxy resin). In order to determine the abrasive properties, an original research stand was made, on which the composites were tested using counter-samples made of an aluminum alloy. The mass loss of samples and counter-samples after the friction test was measured and determined. Changes in the electrospindle supply current and rotational measurements were also made. The values measured and determined in the tests were used as indicators of the abrasiveness of composite materials. It was shown that both the loss of mass of the sample and counter-sample and the parameters of the electrospindle operation are good, convenient indicators of the abrasive properties of the tested materials. The obtained results were subjected to statistical analyses. Optical 3D scans of the surfaces of exemplary samples were presented. Full article

Functional glass surfaces with tunable wettability are of growing interest in optical, biomedical, and architectural applications. In this study, we investigate the influence of femtosecond laser processing parameters—including power, scanning speed, and repetition rate—on the surface morphology, wettability, and optical properties of Panda glass. Laser structuring generated microscale ablation features and increased surface roughness (arithmetic mean height, Sa, rising from ~0.02 µm for pristine glass to ~1.85 µm under optimized conditions). The treated surfaces exhibited enhanced hydrophobicity, with static water contact angles up to ~82° and sliding angles exceeding 50°, indicating significant droplet pinning. Optical characterization further showed a reduction in transmittance at 550 nm from ~92% (pristine) to ~68% after laser treatment, consistent with increased scattering by surface textures. These findings demonstrate that femtosecond laser processing is an effective mask-free method to enhance the hydrophobicity of glass surfaces and establish clear process–structure–property relationships, providing guidance for future optimization toward superhydrophobic performance. Full article

This study investigates the effects of different tungsten (W) doping contents on the optical transmittance, surface roughness, residual stress, and microstructure of evaporated vanadium dioxide (VO₂) thin films. W-doped VO₂ thin films with varying tungsten concentrations were fabricated using electron beam evaporation combined with ion-assisted deposition techniques, and deposited on silicon wafers and glass substrates. The optical transmittances of undoped and W-doped VO₂ thin films were measured by UV/VIS/NIR spectroscopy and Fourier transform infrared (FTIR) spectroscopy. The root mean square surface roughness was measured using a Linnik microscopic interferometer. The residual stress in various W-doped VO₂ films was evaluated using a modified Twyman–Green interferometer. The surface morphological and structural characterization of the W-doped VO₂ thin films were performed by field-emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD). Raman spectroscopy was used to analyze the structure and vibrational modes of different W-doped VO₂ thin films. These results show that the addition of tungsten significantly alters the structural, optical, and mechanical properties of VO₂ thin films. Full article