Search Results (749)

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

Intermuscular bones (IBs), unique skeletal features found only in teleost fishes, pose significant challenges to food processing and consumption. While recent studies have identified several key genetic regulators of IB development, the role of mechanosensory mechanisms remains largely unexplored. This study investigated the role of Piezo1, a critical mechanosensitive ion channel, in IB formation using zebrafish and crucian carp models. Our findings demonstrated that piezo1 was expressed in the myoseptum of zebrafish, and CRISPR/Cas9-mediated knockout of this gene resulted in shorter and smaller IBs. Similar knockout experiments in crucian carp confirmed the conserved role of Piezo1 across cyprinid species. These results established Piezo1 as a key regulator of IB development, providing new insights into the molecular mechanisms underlying this process and suggesting potential strategies for breeding IB-free fish strains through modulation of mechanosensory pathways. Full article

Background and Objectives: Lateral osteotomies in rhinoplasty run adjacent to the lacrimal drainage system (LDS), risking postoperative tearing. Piezoelectric (piezo) devices enable precise bone cuts that may reduce LDS trauma. We compared the 1-month incidence of objective lacrimal dysfunction after piezo versus classic osteotomy. Materials and Methods: Retrospective, single-center controlled cohort (1 January 2024–1 January 2025) at a tertiary ENT clinic. Consecutive patients aged 19–45 with pre-operative paranasal sinus CT and no prior lacrimal disorder were grouped by osteotomy technique (piezo vs. classic; n = 65 per arm). Assessments were performed at postoperative day 7–10 and at 1, 3, and 6–12 months. The primary endpoint was 1-month objective lacrimal dysfunction, defined as fluorescein dye disappearance test (FDDT) grade ≥1 or reflux/resistance on irrigation plus symptoms (Munk ≥2). Pre-specified statistical tests were used. Results: Early tearing favored piezo. At week 1, epiphora occurred in 32.3% with piezo versus 46.1% with classic (p = 0.041); by month 6, rates were 4.6% versus 15.1% (p = 0.031). Differences at months 1 and 3 also favored piezo but were not statistically significant (p = 0.062 and p = 0.088). FDDT positivity was lower with piezo at week 1 (23.0% vs. 38.4%, p = 0.045) and month 6 (3.0% vs. 10.7%, p = 0.048). Irrigation obstruction was less frequent with piezo at week 1 (7.6% vs. 21.5%, p = 0.026), but groups converged by months 1 (15.4% vs. 12.3%, p = 0.80) and 3 (6.2% vs. 4.6%, p > 0.99). Punctum stenosis/occlusion remained uncommon in both groups without significant differences. Conclusions: Piezo-assisted lateral osteotomy is associated with less early lacrimal dysfunction and lower 6-month epiphora compared with the classic technique. Convergence of irrigation findings by 1–3 months suggests postoperative edema as the dominant transient mechanism. Given the retrospective, single-center design and low event rates, multicenter prospective studies powered for early LDS outcomes are warranted. Full article

To solve the issues of insufficient working stroke, low accuracy, and limited response time of stages for vibration-assisted polishing, a two-degree-of-freedom (2-DOF) micro-positioning stage is proposed in this paper. To compensate for the limited stroke of piezoelectric actuator, a bridge–lever amplification mechanism was designed to magnify output displacement. Based on Castigliano’s second theorem and elastic beam theory, static modeling of amplification mechanisms, guiding beams, and transmitting rods was presented. Then, the analytical models of the stage were derived. To validate the accuracy of the analytical model, finite element simulations were performed, demonstrating that the error between theoretical and simulation results is 4.6%. Notably, the stage exhibits kinematic decoupling characteristics and excellent dynamic performances. The research results can provide effective insights for developing a large-stroke piezo-actuated micro-positioning stage with good dynamic performance for vibration-assisted polishing. Full article

Piezoelectric materials are fundamental elements in modern science and technology due to their unique ability to convert mechanical and electrical energy bidirectionally. They are widely employed in sensors, actuators, and energy-harvesting systems. In this work, we investigate the behavior of commercial lead zirconate titanate (PZT) sensors under frequency-mode excitation using a combined approach of impedance spectroscopy and optical interferometry. The impedance spectra reveal distinct resonance–antiresonance features that strongly depend on geometry, while interferometric measurements capture dynamic strain fields through fringe displacement analysis. The strongest deformation occurs near the first kilohertz resonance, directly correlated with the impedance phase, enabling the extraction of an effective piezoelectric constant (~40 pC/N). Moving beyond the linear regime, laser-induced excitation demonstrates optically driven activation of piezoelectric modes, with a frequency-dependent response and nonlinear scaling with optical power, characteristic of coupled pyroelectric–piezoelectric effects. These findings introduce a frequency-mode approach that combines impedance spectroscopy and optical interferometry to simultaneously probe electrical and mechanical responses in a single setup, enabling non-contact, frequency-selective sensing without surface modification or complex optical alignment. Although focused on macroscale ceramic PZTs, the non-contact measurement and activation strategies presented here offer scalable tools for informing the design and analysis of piezoelectric behavior in micro- and nanoscale systems. Such frequency-resolved, optical-access approaches are particularly valuable in the development of next-generation nanosensors, MEMS/NEMS devices, and optoelectronic interfaces where direct electrical probing is challenging or invasive. Full article

Parkinson’s disease (PD) is the second most common neurodegenerative disorder, characterized primarily by motor impairments due to the loss of dopaminergic neurons. Despite extensive research, the precise causes of PD remain unknown, and reliable non-invasive biomarkers are still lacking. This study aimed to explore gene expression profiles in peripheral blood to identify potential biomarkers for PD using machine learning approaches. We analyzed microarray-based gene expression data from 105 individuals (50 PD patients, 33 with other neurodegenerative diseases, and 22 healthy controls) obtained from the GEO database (GSE6613). Preprocessing was performed using the “affy” package in R with Expresso normalization. Feature selection and classification were conducted using a decision tree approach (C4.5/J48 algorithm in WEKA), and model performance was evaluated with 10-fold cross-validation. Additional classifiers such as Support Vector Machine (SVM), the Naive Bayes classifier and Multilayer Perceptron Neural Network (MLP) were used for comparison. ROC curve analysis and Gene Ontology (GO) enrichment analysis were applied to the selected genes. A nine-gene decision tree model (TMEM104, TRIM33, GJB3, SPON2, SNAP25, TRAK2, SHPK, PIEZO1, RPL37) achieved 86.71% accuracy, 88% sensitivity, and 87% specificity. The model significantly outperformed other classifiers (SVM, Naive Bayes, MLP) in terms of overall predictive accuracy. ROC analysis showed moderate discrimination for some genes (e.g., TRAK2, TRIM33, PIEZO1), and GO enrichment revealed associations with synaptic processes, inflammation, mitochondrial transport, and stress response pathways. Our decision tree model based on blood gene expression profiles effectively discriminates between PD, other neurodegenerative conditions, and healthy controls, offering a non-invasive method for potential early diagnosis. Notably, TMEM104, TRIM33, and SNAP25 emerged as promising candidate biomarkers, warranting further investigation in larger and synthetic datasets to validate their clinical relevance. Full article

A prescribed-performance-based sliding mode control method with feed-forward inverse compensation is proposed in this study to improve the micropositioning accuracy and convergence speed of a piezoelectric actuator (PEA). Firstly, the piezo-actuated micropositioning system is described by a Hammerstein structure model, and an inverse Prandtl–Ishlinskii (PI) model was employed to compensate for its hysteresis characteristics. Then, considering modelling errors, inverse compensation errors, and external disturbances, a new prescribed performance function (PPF) with an exponential dynamic decay rate was developed to describe the constrained region of the errors. We then transformed the error into an unconstrained form by constructing a monotonic function, and the sliding variables were obtained by using the transformation error. Based on this, a sliding mode controller with a prescribed performance function (SMC-PPF) was designed to improve the control accuracy of PEAs. Furthermore, we demonstrated that the error can converge to the constrained region and the sliding variables are stable within the switching band. Finally, experiments were conducted to verify the speed and accuracy of the controller. The step-response experiment results indicated that the time taken for SMC-PPC to enter the error window was 8.1 and 2.2 ms faster than that of sliding mode control (SMC) and PID, respectively. The ability of SMC-PPF to improve accuracy was verified using four different reference inputs. These results showed that, for these different inputs, the root mean square error of the SMC-PPF was reduced by over $39.6\%$ and $52.5\%$, compared with the SMC and PID, respectively. Full article

Amyotrophic lateral sclerosis (ALS) is a multisystem progressive neurodegenerative disease. A recent theory of ALS onsetting pathogenesis proposed that the initiating primary damage is an acquired irreversible intrafusal proprioceptive terminal PIEZO2 channelopathy with underlying genetic and environmental risk factors. This Piezo2 channelopathy may also disrupt the ultrafast proton-based oscillatory signaling to motor neurons through vesicular transporter 1 (VGLUT1) and to the hippocampus through VGLUT2. As a result, it may gradually degenerate motor neurons in which process K_v1.2 ion channels are gradually depleted. It also gradually depletes heat shock transcription factor-1 (HSF-1) in the hippocampus, hence negatively affecting adult hippocampal neurogenesis. Syndecans, especially syndecan-3 (SDC3) in the nervous system, may act as critical players in the maintenance of the crosstalk between Piezo ion channels. Hence, our goal was to reanalyze the potential pathogenic gene variants from the cohort of our previous ALS study with a special focus on the aforementioned genes. Reanalysis of data formerly acquired by whole-exome sequencing of 21 non-related adult ALS patients was carried out with a focus on 28 genes. Accordingly, we identified charge-altering variants of SDC3 in 13 patients out of 21 that may contribute to the impairment of the Piezo crosstalk, and the progressive loss of the proposed proton-based signaling to motor neurons and to the hippocampus. A variant of uncertain significance was identified in the KCNA2 gene that may facilitate the faster loss of K_v1.2 ion function on motor neurons when Piezo2 channelopathy prevails. Not to mention that one variant was identified in the potassium current rectifying ion channels encoding KCNK1 and KCNK16 genes that may also propel the ALS disease process and provide the autoimmune-like pathogenic background. Moreover, Piezo2 channelopathy likely promotes diminishing HSF1 function in the hippocampus in the presence of the identified HSF1 variant. The current findings may support the ALS onsetting acquired irreversible Piezo2 channelopathy-induced pathogenesis. However, the preliminary nature of these findings needs validation and further functional studies on cohorts with a larger sample size in the future. Full article