Search Results (747)

This work presents the design, fabrication, and experimental characterization of microelectromechanical system (MEMS) ultrasonic transducers engineered for multi-frequency operation in photoacoustic imaging (PAI). The proposed devices integrate multiple resonant geometries, including circular diaphragms, floated crosses, anchored cross membranes, and cantilever arrays, within compact footprints to overcome the inherently narrow frequency response of conventional MEMS transducers. All devices were fabricated using the PiezoMUMPs commercial microfabrication process, with finite element simulations guiding modal optimization and laser Doppler vibrometry used for experimental validation in air. The circular diaphragm exhibited a narrowband response with a dominant resonance at 1.69 MHz and a quality factor (Q) of 268, confirming the bandwidth limitations of traditional geometries. In contrast, complex designs such as the floated cross and cantilever arrays achieved significantly broader spectral responses, with resonances spanning from 275 kHz to beyond 7.5 MHz. The cantilever array, with systematically varied arm lengths, achieved the highest modal density through asynchronous activation across the spectrum. Results demonstrate that structurally diverse MEMS devices can overcome the bandwidth constraints of traditional piezoelectric transducers. The integration of heterogeneous MEMS geometries offers a viable approach for broadband sensitivity in PAI, enabling improved spatial resolution and depth selectivity without compromising miniaturization or manufacturability. Full article

Biofuels have emerged as a promising alternative to conventional fuels, offering improved environmental sustainability. Nevertheless, inadequate control of their physicochemical properties can lead to increased emissions and potential engine damage. Existing methods for regulating these properties depend on costly and sophisticated laboratory equipment, which poses significant challenges for integration into industrial production processes. Three-dimensional printing technology provides a cost-effective alternative to traditional fabrication methods, offering particular benefits for the development of low-cost designs for detecting liquid properties. In this work, we present a sensor system for assessing biofuel solutions. The presented device employs piezoelectric sensors integrated with 3D-printed, liquid-filled cells whose structural design is refined through experimental validation and novel optimization strategies that account for sensitivity, recovery and resolution. This system incorporates discrete electronic circuits and a microcontroller, within which artificial intelligence algorithms are implemented to correlate sensor responses with fluid viscosity and density. The proposed approach achieves calibration and resolution errors as low as 0.99% and $1.48\times {10}^{-2}$ mPa·s for viscosity, and 0.0485% and $1.9\times {10}^{-4}$ g/mL for density, enabling detection of small compositional variations in biofuels. Additionally, algorithmic methodologies for dimensionality reduction and data treatment are introduced to address temporal drift, enhance sensor lifespan and accelerate data acquisition. The resulting system is compact, precise and applicable to diverse industrial liquids. Full article

Energy harvesting systems face performance limitations, and existing optimizations are not always sufficient; this study addresses these gaps by enhancing piezoelectric energy systems. To improve the performance of piezoelectric energy harvesting systems, an optimization methodology is developed in this study. Since the mechanical strain distribution directly affects energy conversion efficiency, this issue is addressed through optimization of the thickness geometry of a common cantilever-type harvester elastic substrate element via a state-space gradient projection method combined with design sensitivity analysis. The gradient projection method is implemented in MATLAB R2024b software to determine the optimal elastic substrate design, after which the optimized design is simulated in COMSOL 6.3 Multiphysics for strain analysis in a transient study. The optimized cantilever designs are produced by 3D printing using a photopolymer and experimentally validated using piezo sensors and laser measurements for dynamic analysis. Theoretically compared with traditional uniform beams, the optimized cantilever designs maximize strain along the upper layer of the elastic substrate element, leading to a substantial increase in the energy conversion efficiency. This maximization is validated by experimental measurements showing a significant increase in strain in the elastic substrate (approximately 30% at the first eigenfrequency and 70% at the second). The correlation between the experimentally obtained data and the simulation results validates the optimization results. Deviation between the results did not exceed 3% and indicates that cantilever-type energy harvesters with optimized thickness profiles outperform traditional rectangular beams in energy conversion efficiency. Full article

Hereditary spherocytosis (HS) is the most common inherited red blood cell (RBC) membrane disorder and has traditionally been attributed to defects in cytoskeletal proteins such as spectrin, ankyrin, band 3, and protein 4.2. Growing evidence, however, shows that disturbances in ion transport also contribute to HS pathophysiology. This review summarizes current understanding of HS by integrating membrane structural defects with abnormalities in ion homeostasis and highlights the diagnostic value of osmotic gradient ektacytometry (OGE). Beyond membrane instability, HS erythrocytes exhibit increased cation permeability with abnormal Na⁺ influx and K⁺ loss, leading to cellular dehydration, elevated mean corpuscular hemoglobin concentration (MCHC), and reduced deformability. Dysregulation of mechanosensitive and Ca²⁺-activated K⁺ channels (PIEZO1, KCNN4) may modulate disease expression. OGE—now the reference functional test for RBC deformability—identifies reproducible phenotypes reflecting hydration status, including dehydrated (HS1) and partially hydrated (HS2) HS profiles. When combined with next-generation sequencing (NGS), OGE improves differentiation between HS and overlapping membranopathies such as hereditary xerocytosis or stomatocytosis. In conclusion, HS is a multifactorial disorder resulting from the interplay between cytoskeletal fragility, oxidative stress, and dysregulated ion transport. Integrated diagnostic strategies that combine hematologic indices, OGE, and targeted NGS enhance diagnostic accuracy, support genotype–phenotype interpretation, and guide individualized clinical management. Future efforts should focus on ion-channel modulation and wider adoption of functional assays in precision hematology. Full article

Mechanical loading generated during physical activity and exercise is a fundamental determinant of musculoskeletal development, adaptation, and regeneration. Exercise-based mechanotherapy, encompassing structured movement, resistance training, stretching, and device-assisted loading, has evolved from empirical rehabilitation toward mechanism-driven and precision-oriented therapeutic strategies. At the macroscopic level, biomechanical principles governing load distribution, stress–strain relationships, and tissue-specific adaptation provide the physiological basis for exercise-induced tissue remodeling. At the molecular level, mechanical cues are transduced into biochemical signals through conserved mechanotransduction pathways, including integrin–FAK–RhoA/ROCK signaling, mechanosensitive ion channels such as Piezo, YAP/TAZ-mediated transcriptional regulation, and cytoskeleton–nucleoskeleton coupling. These mechanisms orchestrate extracellular matrix (ECM) remodeling, cellular metabolism, and regenerative responses across bone, cartilage, muscle, and tendon. Recent advances in mechanotherapy leverage these biological insights to promote musculoskeletal tissue repair and regeneration, while emerging engineering innovations, including mechanoresponsive biomaterials, 4D-printed dynamic scaffolds, and artificial intelligence-enabled wearable systems, enable mechanical loading to be quantified, programmable, and increasingly standardized for individualized application. Together, these developments position exercise-informed precision mechanotherapy as a central strategy for prescription-based regenerative rehabilitation and long-term musculoskeletal health. Full article

Chromatin architecture is highly dynamic, undergoing nanoscale rearrangements throughout the cell cycle and in response to environmental cues. In this study, we employed high-resolution stochastic optical reconstruction microscopy (STORM) to visualize chromatin organization and cellular plasticity at the nanoscale in two osteosarcoma cell lines, U2OS and MG63. To promote a tumor-suppressive bone microenvironment, we applied three biophysical modalities, namely mechanical vibration, electrical stimulation, and optical pulses, each previously linked to altered tumor behavior by reprogramming cells and generating induced tumor-suppressing (iTS) cells. These stimuli enlarged nuclear size and disrupted nuclear envelope integrity, as revealed by increased surface roughness. Critically, all three modalities transiently scattered nucleosome clusters, indicating chromatin decondensation as a hallmark of iTS cell generation. iTS cells exhibited elevated expression of histone demethylases lysine demethylase 3A (KDM3A) and lysine demethylase 4 (KDM4), accompanied by reduced levels of trimethylated histone H3 lysine 9 (H3K9me3). Consistently, pharmacological agents—Trichostatin A as a histone deacetylase inhibitor and chaetocin as a histone methyltransferase inhibitor—induced nucleosome scattering and converted U2OS cells into iTS cells, whose conditioned media exerted tumor-suppressive effects. Our findings highlight nucleosome clustering as a key epigenetic feature responsive to both biophysical and chemical cues, underscoring its role in microscale chromatin remodeling and reprogramming of the tumor microenvironment. Full article

Osteoarthritis (OA) is a multifactorial degenerative joint disease in which aberrant mechanical cues act in concert with metabolic dysregulation and chronic low-grade inflammation, with chondrocyte hypertrophy representing a key pathological event driving cartilage degeneration. Alterations in extracellular matrix (ECM) properties—including mechanical loading, stiffness and viscoelasticity, topological organization, and surface chemistry—regulate hypertrophic differentiation and matrix degradation in a zone-, stage-, and scale-dependent manner. Microscale measurements often reveal localized stiffening in superficial zones during early OA, whereas bulk tissue testing can show softening or heterogeneous changes in deeper zones or advanced stages, highlighting the context-dependent nature of ECM mechanics. These biophysical signals are sensed by integrin-based adhesion complexes, primary cilia, mechanosensitive ion channels (TRP/Piezo), and the actin cytoskeleton–nucleus continuum, and are transduced into intracellular pathways with zone- and stage-specific effects, governing chondrocyte fate under physiological and osteoarthritic conditions. Mechanism-based anti-hypertrophic strategies include biomimetic scaffold design for focal defects, dynamic mechanical stimulation targeting early OA, and multimodal approaches integrating mechanical cues with biochemical factors, gene modulation, drug delivery, or cell-based therapies. Collectively, this review provides an integrated mechanobiological framework for understanding cartilage degeneration and highlights emerging opportunities for disease-modifying interventions targeting chondrocyte hypertrophy. Full article

Dental pain often arises from the compromised integrity of the tooth pulp due to dental injury or caries. The dentin–pulp complex has long been considered to be central to the unique biology of dental pain. Most trigeminal ganglion afferents projecting into tooth pulp are myelinated neurons, which lose their myelination at the site of peripheral dentin innervation. The pulpal afferents likely combine multiple internal and external stimuli to mediate nociception and maintain pulp homeostasis. Transient receptor potential (TRP) ion channels in neurons and odontoblasts, along with mechanosensitive ion channels such as Piezo, form a key molecular hub for pulpal nociception by sensing thermal, chemical, and hydrodynamic stimuli. Among these, TRP vanilloid 1 (TRPV1) mediates nociception and the release of calcitonin-gene-related peptides (CGRPs), while TRP canonical 5 (TRPC5) mediates cold pain. TRP melastatin 8 (TRPM8) mediates the transduction of hyperosmotic stimuli. Pulpitis elevates endogenous TRPV1 and TRPA1 agonists, while inflammatory mediators sensitize TRP channels, amplifying pain. CGRP recruits immune cells and promotes bacterial clearance and reparative dentinogenesis, yet the roles of TRP channels in these processes remain unclear. Future studies should use advanced multi-omics and in vivo or organotypic models in animal and human teeth to define TRP channel contributions to pain, immune responses, and regeneration. Understanding neuronal and non-neuronal TRP channel interactions and their integration with other ion channels may enable novel analgesic and regenerative strategies in dentistry. Full article

Despite extensive research on fascial mechanobiology, no unified mechanotransduction framework has been established to explain how mechanical forces translate into adaptive cellular responses in fascial tissue. This narrative review synthesizes evidence from mesenchymal cell and fibroblast research to propose the Ca²⁺–Hyaluronan (CHA) axis as a comprehensive mechanotransduction feedback loop for fascia phenomenology. The CHA framework describes how mechanical stress activates Ca²⁺ channels (Piezo1, TRPV4, P2Y2), triggering HAS2-mediated hyaluronan (HA) synthesis. The molecular weight of synthesized HA then determines receptor signaling outcomes: high-molecular-weight HA binds CD44 to promote tissue stability and quiescence, while low-molecular-weight HA fragments activate RHAMM to drive remodeling and repair—a dynamic oscillation termed “Quiet or Riot.” Three key conclusions emerge: First, the CHA framework is well supported by existing literature on mesenchymal cells, providing a testable model for fascial mechanobiology. Second, HA molecular weight dynamics and CD44/RHAMM oscillation have direct implications for optimizing movement, manual therapy, and rehabilitative interventions. Third, while HA-CD44/RHAMM signaling is broadly implicated in tissue remodeling, Ca²⁺-dependent regulatory mechanisms specific to fasciacytes require experimental validation. A critical translational gap remains: the absence of quantitative mechanical thresholds distinguishing beneficial from pathological loading limits clinical application. Future research should employ 3D matrix models, live imaging, receptor manipulation, and omics profiling to establish these thresholds and validate the CHA framework in fasciacytes. Understanding fascial mechanotransduction through the CHA loop may transform approaches to movement prescription, manual therapy, and treatment of fascial dysfunction. Full article

Age-associated hair loss is primarily driven by decreased function and proliferation of hair follicle stem cells (HFSCs), often exacerbated by increased inhibitory signaling and changes in the stem cell niche. Macrophage polarization to the anti-inflammatory M2 phenotype is known to increase stem cell proliferation. We investigated the effects of poly-D,L-lactic acid (PDLLA) on hair growth in middle-aged skin, focusing on its role in modulating macrophage polarization and HFSC activity. Senescent macrophages were analyzed for Piezo1 activity, macrophage polarization, and secretion of hepatocyte growth factor (HGF) and insulin-like growth factor-1 (IGF-1) after PDLLA treatment. Downstream effects on HFSC proliferation, stemness, and Wnt signaling were assessed, including inhibition experiments using the Piezo1 blocker GsMTx4. In vivo analyses assessed hair follicle number, diameter, length, anagen duration, and hair coverage following PDLLA administration in middle-aged mice. PDLLA increased Piezo1 expression and activity in senescent macrophages, enhancing M2 polarization and secretion of HGF and IGF-1. This activated the RAS/ERK signaling pathway, promoting HFSC proliferation and stemness. Furthermore, PDLLA upregulated Wnt signaling molecules (Wnt3a, Wnt10b, and β-catenin) and anagen phase-related factor (Axin2, LEF1, and Lgr5), which were decreased by GsMTX4. In middle-aged animal skin, PDLLA administration led to increased hair follicle number, diameter, and length, as well as prolonged anagen and greater hair coverage. Collectively, these findings suggest that PDLLA rejuvenates the middle-aged skin microenvironment, at least in part through Piezo1-associated M2 macrophage polarization and enhanced HFSC function, offering a promising therapeutic strategy for age-related hair loss targeting both the immune and the stem cell compartments. Full article

Mutations in the Piezo1 mechanosensor are associated with blood cell anomalies. The objective of our study was to explore the role of Piezo1 in the development and function of the megakaryocyte (MK) lineage. To this end, PF4-Cre mice, bearing Cre recombinase under the control of the Pf4 gene promoter—which drives expression to hematopoietic progenitors and to the MK/platelet lineage—were crossbred with Piezo1-floxed mice to generate Piezo1 knockout (KO) mice. In our results, the hematopoietic stem cell (HSC) count—including Multipotent Progenitors 2 (MPP2) progenitors that give rise to MKs—tended to be augmented in KO mice, while the level of MPP3 progenitors that give rise to white blood cells (WBCs) tended to be reduced, as compared to matching controls. The level of circulating WBCs was significantly reduced in the KO mice compared to controls. In addition, while platelet count was modestly elevated, platelet activation response was reduced in Piezo1 KO mice compared to controls. MK levels and ploidy were similar in both groups. Baseline serum pro-and anti-inflammatory cytokine profiles were also similar in the two experimental groups. However, upon LPS challenge, there was a significant reduction in IL-6 and INF-γ levels in the sera of Piezo1 KO mice compared to controls. Our findings point to an immunoregulatory and thrombotic potential of Piezo1 in relatively rare bone marrow cells, along with an ability to modulate WBC count. Full article

The development of advanced semiconductor-based catalysts for the rapid degradation of emerging pharmaceutical pollutants in water remains a critical challenge in environmental science. In this study, we present the synthesis, characterization, and catalytic performance of zinc oxide (ZnO) microtetrapods decorated with plasmonic Ag nanoparticles. These microtetrapods have been designed to enhance piezo-, photo-, and piezo-photocatalytic degradation of metronidazole (MNZ), a persistent antibiotic contaminant. ZnO microtetrapods were synthesized by high-temperature pyrolysis and using atmospheric-pressure microwave nitrogen plasma, followed by photochemical deposition of Ag nanoparticles at various precursor concentrations (0–1 mmol AgNO₃). The structural integrity of the samples was confirmed through X-ray diffraction (XRD) analysis, while the morphology was examined using scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDX). Additionally, spectroscopic analysis, including Raman, electron paramagnetic resonance (EPR), and photoluminescence (PL) spectroscopy, was conducted to verify the successful formation of heterostructures with adjustable surface loading of Ag. It has been shown that ZnO microtetrapods decorated with plasmonic Ag nanoparticles exhibit Raman-active properties. A systematic evaluation under photocatalytic, piezocatalytic, and combined piezo-photocatalytic conditions revealed a pronounced volcano-type dependence of catalytic activity on Ag content, with the 0.75 mmol composition exhibiting optimal performance. In the presence of both light irradiation and ultrasonication, the optimized Ag/ZnO composite exhibited 93% degradation of MNZ within a span of 5 min, accompanied by an apparent rate constant of 0.56 min⁻¹. This value stands as a significant improvement, surpassing the degradation rate of pristine ZnO by over 24-fold. The collective identification of defect modulation, plasmon-induced charge separation, and piezoelectric polarization as the predominant mechanisms driving enhanced reactive oxygen species (ROS) generation is a significant advancement in the field. These findings underscore the synergistic interplay between plasmonic and piezoelectric effects in oxide-based heterostructures and present a promising strategy for the efficient removal of recalcitrant water pollutants using multi-field activated catalysis. Full article

Introduction: Chronic rhinosinusitis (CRS) with frontal sinus outflow tract (FSOT) obstruction frequently requires frontal beak reduction during endoscopic sinus surgery (ESS). While technical approaches such as rotary drilling or piezoelectric osteotomy may differ in precision and tissue preservation, it is unclear whether surgical instrument choice or patient-specific clinical characteristics influence postoperative quality of life (QoL). Methods: In this prospective cohort study, 49 adult CRS patients undergoing ESS with frontal beak reduction were enrolled (28 males, mean age 50 ± 15 years). Osteotomy was performed using either a conventional drill (n = 25) or piezoelectric knife (n = 24). Baseline clinical data included presence of nasal polyps, asthma, and radiologic severity (Lund–Mackay and Zinreich CT scores). Outcomes included patient-reported symptoms with the 22-item Sino-Nasal Outcome Test (SNOT-22) and visual analogue scale (VAS), and endoscopic Lund–Kennedy scores, recorded preoperatively and at 1, 4, and 24 weeks postoperatively. Results: Both groups demonstrated significant postoperative improvement in SNOT-22 and VAS scores. No significant correlation was observed between SNOT-22 changes and Lund–Kennedy scores in either tool group. Presence of nasal polyps was associated with higher pre- and postoperative Zinreich and Lund–Mackay scores (p < 0.05). Asthma was linked to higher early postoperative symptom burden (nasal blockage, clear discharge; p < 0.05). Tool choice did not significantly influence QoL recovery or modify the effect of clinical characteristics on outcomes. Conclusions: Postoperative QoL improvement was driven primarily by baseline disease phenotype—particularly nasal polyposis and asthma—while the choice of osteotomy instrument did not significantly influence recovery trajectories. The Zinreich score provided additional phenotypic stratification in CRS with FSOT obstruction. Full article

Background: Biomechanical factors behind non-contact anterior cruciate ligament (ACL) injury in soccer and handball are still not fully understood. Unfortunately, ACL injuries more frequently appear in game situations. Aim: To describe a possible ACL injury mechanism in male professional handball players using MRI images and our own biomechanical model. Hypothesis: The friction parameters of the surface have extreme importance in the non-contact ACL injury mechanism. If the surface is more slippery, the horizontal component of the ground reaction force (GRF) will be smaller, consequently the torque originating from the GRF acting on the knee will be greater during the landing phase of a vertical jump, resulting in greater abduction effect on the knee. Consequently, the risk of knee injury increases. Methods: We have collected MRI images and anthropometric data of 15 healthy male individuals (age 19–23) to create a biomechanical model to calculate the torques in the knee to obtain more knowledge about ACL injury mechanism. Results: The lower extremity lean angle during the landing phase of a jump and friction parameters substantially affect abduction torques in the knee and consequently the risk of ACL injury occurrence. Conclusions: The landing posture when the knee is fully extended during landing is highly unfortunate for the ACL, compared to when the knee is partially flexed. If the knee is fully extended, greater hip abduction will increase the risk of an ACL injury, and if the surface is more slippery, e.g., the surface is wet, the possibility of ACL injury is even greater. In addition, we also applied a molecular working hypothesis through acquired Piezo2 channelopathy theory, as the proposed preceding neuromuscular disruptor prior to non-contact ACL injury. Full article

Nanotechnology offers powerful new tools to enhance food quality monitoring and safety assurance. In the food industry, nanoscale materials (e.g., metal, metal oxide, carbon, and polymeric nanomaterials) are being integrated into sensory systems to detect spoilage, contamination, and intentional food tampering with unprecedented sensitivity. Nanosensors can rapidly identify foodborne pathogens, toxins, and chemical changes that signal spoilage, overcoming the limitations of conventional assays that are often slow, costly, or require expert operation. These advances translate into improved food safety and extended shelf-life by allowing early intervention (for example, via antimicrobial nano-coatings) to prevent spoilage. This review provides a comprehensive overview of the types of nanomaterials used in food sensory applications and their mechanisms of action. We examine current applications in detecting food spoilage indicators and adulterants, as well as recent innovations in smart packaging and continuous freshness monitoring. The advantages of nanomaterials—including heightened analytical sensitivity, specificity, and the ability to combine sensing with active preservative functions—are highlighted alongside important toxicological and regulatory considerations. Overall, nanomaterials are driving the development of smarter food packaging and sensor systems that promise safer foods, reduced waste, and empowered consumers. However, realizing this potential will require addressing safety concerns and establishing clear regulations to ensure responsible deployment of nano-enabled food sensing technologies. Representative figures of merit include Au/AgNP melamine tests with LOD 0.04–0.07 mg L⁻¹ and minute-scale readout, a smartphone Au@carbon-QD assay with LOD 3.6 nM, Fe₃O₄/DPV detection of Sudan I at 0.001 µM (linear 0.01–20 µM), and a reusable Au–Fe₃O₄ piezo-electrochemical immunosensor for aflatoxin B1 with LOD 0.07 ng mL⁻¹ (≈15 × reuse), alongside freshness labels that track TVB-N/amine in near-real time and e-nose arrays distinguishing spoilage stages. Full article