Bioengineering最新文献

This study evaluated the reliability and inter-examiner agreement of the Implant Stability Test (IST) by Anycheck compared to the established Implant Stability Quotient (ISQ) by Osstell across different bone quality types. Seven dental hygienists with varying experience levels performed stability measurements using both devices on standardized implant models representing hard, normal, and soft bone qualities. Both IST and ISQ demonstrated excellent inter-examiner reliability (ICC > 0.90) across all bone quality types, with strong positive correlations (r > 0.85) between measurements regardless of bone density. No significant differences were found in measurement consistency between examiners with different experience levels for either device. The results demonstrate that IST provides comparable reliability to ISQ for implant stability assessment, with excellent inter-examiner agreement and accessibility for practitioners with varying experience levels. The IST system offers practical advantages including elimination of SmartPeg requirements, reduced abutment manipulation, and simplified measurement protocols, supporting its potential as a reliable and cost-effective alternative to traditional ISQ measurements under standardized experimental conditions.

Purpose: Tympanostomy tubes are essential for middle ear ventilation, but conventional long-term tubes carry high perforation rates (12-22%). This study evaluated the Tympanostomy U-Tube (TUT), a novel silicone-based tube designed to minimize perforation risk by redistributing pressure away from the tympanic membrane rim.

Methods: This was a retrospective cohort study of 192 ears in children aged 1-4 years who underwent TUT insertion for chronic otitis media with effusion or recurrent acute otitis media. The primary outcomes were tube insertion time and the permanent perforation rate. Mean follow-up was 38.4 months.

Results: Mean tube insertion time was 21.6 months. Spontaneous extrusion occurred in 18.2% of ears (mean 24.5 months), while 81.8% underwent elective removal (mean 21.0 months). Permanent perforation developed in only 4 ears (2.08%; 95% CI: 0.6-5.2%), substantially lower than rates reported in the literature for conventional long-term tubes (12-22%), although the retrospective design and reliance on historical controls limit direct comparison. Complications were minimal, with otorrhea (36%) responding to topical therapy. Office-based removal was successful in all cases.

Conclusions: The TUT provides intermediate-duration ventilation with a perforation rate comparable to that of short-term tubes, while avoiding the high perforation rates of conventional long-term tubes. Prospective randomized trials are needed to validate these findings.

In fixed orthodontic treatment, brackets are orthodontic attachments bonded to the tooth enamel, and their placement and removal may affect the underlying enamel surface. Enamel degradation is a critical factor for oral health, as it reduces the mechanical strength of teeth and increases susceptibility to caries and erosion. Accurate diagnosis of enamel changes is therefore essential for the evaluation of preventive and restorative treatments. In this study, enamel degradation was investigated via two integrated methods: energy-dispersive X-ray spectroscopy (EDS) and surface roughness measurement. The experimental protocol was performed in three stages: before bracket bonding, after bracket removal, and after applying a remineralization treatment. The experimental design included a repeated-measures structure, with stage (baseline, post-debonding, post-remineralization) as the within-tooth factor and bracket type (sapphire vs. metallic) as the between-tooth factor. Given the violation of the variance homogeneity assumption, group comparisons were ultimately performed using Welch ANOVA followed by Games-Howell post hoc tests, with Bonferroni-adjusted values used for pairwise comparisons. The presence of orthodontic brackets can influence enamel mineralization because the bonding and debonding procedures modify the enamel surface microtopography. These procedures can generate microcracks and surface irregularities, which may affect mineral exchange between enamel and the surrounding environment. In our study, bracket removal led to a significant decrease in the mean atomic percentages of Ca (from 32.65% to 16.37% for sapphire) and P (from 16.35% to 8.60% for sapphire), accompanied by a sharp increase in surface roughness. After remineralization, Ca and P levels increased, while roughness decreased. However, neither the mineral content nor the surface topography fully returned to the initial values, indicating that remineralization achieved only a partial recovery of enamel integrity. These findings highlight that the integrated EDS approach and roughness analysis offer a promising descriptive framework for assessing enamel degradation and monitoring the effectiveness of remineralization therapies. The generated mathematical model provides a powerful descriptive framework for the in vitro data obtained, correlating roughness with mineral composition and treatment stage. However, such a high goodness-of-fit (R² > 0.98) should be interpreted cautiously due to the risk of overfitting. Therefore, rigorous external validation is mandatory before this model can be considered a reliable predictive tool. It also highlights the importance of enamel remineralization therapies after orthodontic treatment, but also the importance of choosing personalized treatment strategies adapted to the enamel type.

Fall-compliant flooring represents a passive fall preventative approach that has emerged as an effective intervention for reducing fall-related injuries, yet its adoption remains limited due to insufficient understanding among end-users and key stakeholders. To address this knowledge gap, this perspective article provides a proof-of-concept for an interactive pedagogical tool designed to use gamification principles to improve understanding of the mechanical behavior of fall-compliant flooring. This two-part perspective article first establishes the scientific foundation through controlled ball drop experiments comparing energy dissipation between fall-compliant and standard flooring. Through video-based tracking analysis, the experiments quantified kinetic energy and force dissipation across spatial and temporal dimensions. Results revealed that fall-compliant flooring exhibits significantly superior spatiotemporal energy dissipation capabilities compared to standard flooring across both force and kinetic energy metrics. Building on these findings, the second part proposes a conceptual framework for a pedagogical tool that translates these experimental insights into an interactive learning experience that could, in future implementations, allow users to conduct hands-on ball drop activities supported by real-time scientific explanations. This approach transforms complex biomechanical concepts into accessible, engaging learning experiences. By combining experiential learning with gamified elements, this tool, termed "Fallville", has the potential to increase fall-injury prevention awareness, deepen understanding of fall-compliant flooring mechanisms, and ultimately accelerate adoption of this proven safety intervention in healthcare and residential settings.

Despite significant improvements in revascularization strategies and medical management, ischemic heart disease (IHD) remains the top cause of mortality and disability worldwide. The myocardium lacks regenerative capacity and consequently, recovery depends on re-establishing microvascular integrity and sustaining angiogenesis to preserve viable myocardium. Emerging and novel bioengineering approaches, such as stem cells, extracellular vesicles (EVs), and matrix-based strategies, seek to address this unmet need by promoting neovascularization and structural restoration. However, clinical translation remains limited by poor engraftment, product variability, and arrhythmogenic risk. Large animal models provide a clinically relevant platform to thoroughly investigate these interventions and ideally enhance their translational potential. This review discusses cellular approaches leveraging stem and progenitor cells and acellular modalities using extracellular vesicles, growth factors, or extracellular matrix-based scaffolds with an emphasis on large animal translational models and clinical trials.

Aim: This study examined how load size and symmetry affect trunk muscle activation patterns, vertical ground reaction forces, and estimated lumbar spine compression during overground walking in individuals with chronic low back pain (CLBP) and those without symptoms. Methods: Thirty male participants (15 with CLBP, 15 controls; ages 23-28 years) performed walking tests under four load conditions: symmetric and asymmetric carriage at 10% and 20% of body weight. Bilateral surface electromyography measured activation from seven trunk muscles (rectus abdominis, external oblique, internal oblique, latissimus dorsi, lumbar erector spinae, multifidus) and the thoracolumbar fascia region, normalized to maximum voluntary isometric contractions (%MVIC). Force plates recorded vertical ground reaction forces synchronized with heel-strike events. A repeated-measures ANOVA with Bonferroni corrections was used to analyze the effects of load configuration and magnitude. Results: Asymmetric loading at 20% body weight caused significantly higher peak vertical ground reaction forces compared to symmetric loading (mean difference = 47.3 N, p < 0.001), with a significant interaction between load magnitude and configuration (p = 0.004, ηp² = 0.26). Participants with CLBP showed consistently higher trunk muscle activation throughout the gait cycle (peak: 37% MVIC vs. 30% MVIC in controls; p < 0.001, d = 1.68), with maximum recruitment at shorter muscle lengths and 24% less activation at optimal length (95% CI: 18.2-29.8%). The lumbar erector spinae and multifidus muscles exhibited the highest activation during asymmetric 20% loading in CLBP participants (0.282 and 0.263%MVIC, respectively), indicating compensatory neuromuscular strategies. Conclusion: Asymmetric load carriage creates disproportionately high mechanical and neuromuscular demands, effects that are greatly amplified in individuals with CLBP. These findings support rehabilitation strategies that improve load distribution and restore motor control, thereby reducing compensatory strain and enhancing trunk stability.

Background: Greater trochanteric pain syndrome (GTPS) is associated with structural tendon alterations and functional impairment. Extracorporeal shockwave therapy (ESWT) is a common treatment, but objective monitoring of tendon remodeling and motor recovery remains limited.

Objective: This study aimed to integrate shear-wave elastography (SWE) expressed in m/s and wearable inertial measurement unit (IMU) as biosensing tools for the quantitative assessment of tendon elasticity, morphology, and hip motion after ESWT in GTPS.

Methods: In a prospective cohort of adults with chronic GTPS, shear wave elastography (SWE) quantified gluteus medius tendon (GMT) elasticity and thickness, while hip abduction range of motion (ROM) was measured using a triaxial inertial measurement unit. Clinical scores on the Visual Analogue Scale (VAS), Harris Hip Score (HHS), Low Extremity Functional Scale (LEFS), and Roles and Maudsley score (RM) were collected at baseline (T0) and at 6 months (T1).

Results: Thirty-five patients completed follow-up. Pain and function improved significantly (VAS, HHS, LEFS, RM; all p < 0.05). SWE values of the affected GMT increased, while tendon thickness decreased yet remained greater than on the contralateral side. Hip abduction ROM increased significantly from T0 to T1 (p < 0.05). Correlation analysis showed a negative association between abduction and pain at T1 (r = -0.424; p = 0.011) and, at baseline, between abduction and VAS (r = -0.428; p = 0.010) and RM (r = -0.346; p = 0.042), and a positive association with LEFS (r = 0.366; p = 0.031). SWE correlated negatively with VAS at T1 (r = -0.600; p < 0.05) and positively with HHS at T1 (r = 0.400; p < 0.05).

Conclusions: Integrating elastography with inertial sensor-based motion analysis provides complementary, quantitative insights into tendon remodeling and functional recovery after ESWT in GTPS. These findings support combined imaging and wearable motion measures to monitor treatment response over time.

Although membrane proteins are of major importance in both physiology and disease, they remain less studied than soluble proteins due to the complex amphiphilic environments required to preserve their structure and function. As a consequence, membrane proteins are under-represented in structural databases. In this work, we present a robust structural characterization of lipid nanodiscs designed to facilitate membrane protein studies by small-angle neutron scattering. By combining small-angle X-ray and neutron scattering, we investigate nanodiscs of three different sizes and three lipid compositions to accommodate a broad range of systems. Specifically, nanodiscs with diameters of approximately 9 nm, 12 nm, and 15 nm were examined. Beyond the commonly used di-myristoyl-phosphatidylcholine lipid, we produced and characterized polar lipid extracts from a Gram-negative bacterium (Escherichia coli) and a Gram-positive bacterium (Bacillus subtilis) under both protonated and deuterated conditions. In conclusion, solubility-enhanced variants of the scaffold protein yield more stable nanodiscs and are therefore preferable for extended structural investigations. The co-fitting of small-angle scattering data provides robust geometrical models of these nanodiscs, which can be treated as well-defined reference systems for future studies of membrane proteins in native-like lipid environments.

Recurrent depressive disorder (RDD) and bipolar disorder (BD) are the most common affective disorders worldwide. However, the pathogenesis of these disorders remains far from understood. Macromolecular proton fraction (MPF) mapping is a sensitive and specific quantitative MRI method for the assessment of brain tissue myelination, but its clinical value for affective disorders remains unknown. This cross-sectional study employed fast MPF mapping on a 1.5 T MRI scanner using the single-point synthetic reference method to investigate myelin abnormalities in white matter of RDD and BD patients. ANOVA revealed a significant main effect of the group (RDD vs. BD vs. two age-matched control groups; F (3.76) = 7.42, p < 0.001, η² = 0.227). MPF values were significantly reduced in RDD versus BD patients (p < 0.001). BD showed elevated MPF compared to controls (p = 0.01). MPF levels showed significant weak-to-moderate correlations with clinical scales of affective disorders. These findings demonstrate divergent cerebral myelination patterns-hypomyelination in RDD versus an increased myelin content in BD. In conclusion, MPF mapping demonstrated a promise as a marker of myelin content changes in affective disorder.

Patients with severe structural tooth wear present significant restorative challenges, including compromised oral function and the loss of essential anatomical landmarks such as marginal ridges, incisal edges, cusps, occlusal planes, and vertical dimension of occlusion (VDO). Successful management requires meticulous diagnosis, comprehensive treatment planning, and careful selection of restorative materials with appropriate biomechanical properties. Digital technologies have become integral to this process, particularly for enhancing diagnostic accuracy, material selection, and tooth preparation design within a fully digital workflow. This clinical case report illustrates a complete digital approach, beginning with an initial intraoral scan merged with a digital wax-up STL file featuring varying translucency dimensions to guide tooth preparation. This workflow enabled precise planning of tooth reduction, accurate assessment of available interocclusal space, and determination of material thickness requirements prior to irreversible procedures. Additionally, the integration of digital visualization improved patient communication, treatment predictability, and interdisciplinary collaboration. Overall, this case highlights the value of CAD/CAM technology in supporting complex oral rehabilitation for patients with advanced tooth wear, demonstrating its capacity to enhance efficiency, precision, and outcome quality in full-mouth zirconia ceramic restorations.