Search Results (1,120)

Electro-optic modulators in the near-infrared spectrum are finding applications in atomic clocks, quantum sensing, quantum information processing, and high-precision measurement. We developed thin-film lithium niobate electro-optic modulators operating at 795 nm for modulation around the D₁ line of ⁸⁷Rb with satisfactory overall performance. Specifically, we made a systematic improvement to reduce the insertion loss, including widening the modulation waveguides, thickening the overcladding, polishing and coating the facets. The fabricated device possesses a low insertion loss of 7.6 dB, an extinction ratio exceeding 30 dB, a 3 dB modulation bandwidth of ~22 GHz, a half-wave voltage-length product of ~1.8 Vcm, and strong adaptability for packaging. Full article

Understanding the mechanical behavior of implanted neural electrode arrays is crucial for BCI development, which is the foundation for ensuring surgical safety, implantation precision, and evaluating electrode efficacy and long-term stability. Therefore, a reliable FE models are effective in reducing animal experiments and are essential for a deeper understanding of the mechanics of the implantation process. This study established a novel finite element model to simulate neural electrode implantation into brain tissue, specifically characterizing the nonlinear mechanical responses of brain tissue. Synchronized electrode implantation experiments were conducted using ex vivo porcine brain tissue. The results demonstrate that the model accurately reproduces the dynamics of the electrode implantation process. Quantitative analysis reveals that the implantation force exhibits a positive correlation with insertion depth, the average implantation force per electrode within a multi-electrode array decreases with increasing electrode number, and elevation in electrode size, shank spacing, and insertion speed each contribute to a systematic increase in insertion force. This study provides a reliable simulation tool and in-depth mechanistic analysis for predicting the implantation forces of high-density neural electrode arrays and offer theoretical guidance for optimizing BCI implantation device design. Full article

Objective: The aim of this study is to develop and evaluate the antibacterial and anti-biofilm efficacy of ciprofloxacin-coated tympanostomy tubes (TTs) using a sustained-release varnish (SRV-CIPRO) and introduce a novel tympanic membrane model for preclinical evaluation. Study Design: This was an in vitro experimental study. Setting: This study was conducted in a biofilm research laboratory in an academic medical center. Methods: Sterile fluoroplastic TTs were coated with SRV-CIPRO or placebo varnish. A novel tympanic membrane (TM) model was developed using a layered agar–plastic system. Antibacterial activity, biofilm inhibition, and bacterial viability were assessed through agar diffusion, MTT, ATP quantification, HR-SEM, and SD-CLSM. Results: SRV-CIPRO-coated TTs exhibited sustained antibacterial activity for up to 10 days. Compared to the placebo, SRV-CIPRO significantly inhibited biofilm formation, reduced metabolic activity, and decreased bacterial viability (p < 0.05). Imaging confirmed fewer bacterial colonies on SRV-CIPRO TTs. The TM model allowed realistic testing of tube insertion and infection simulation. Conclusion: SRV-CIPRO-coated TTs offer sustained antibiotic delivery, potentially reducing postoperative otorrhea and biofilm-related complications. The TM model provides a platform for preclinical evaluation of middle ear devices. Full article

We present a low-loss fan-in/fan-out (FIFO) device fabricated from a bundle of chemically etched optical fibers integrated within a standard FC/PC connector. The device demonstrates efficient coupling with insertion losses of 0.32 dB and 0.40 dB at wavelengths of 1310 nm and 1550 nm, respectively. Crosstalk and back reflection were measured to be below −41.8 dB and 51.3 dB, confirming high channel isolation and minimal signal degradation. This compact and connectorized solution offers a practical approach for scalable multicore fiber interfacing in advanced optical communication systems. Full article

Multiple sclerosis (MS) is a chronic disease of the central nervous system that significantly impairs gait and mobility, contributing to a high risk of falls, reduced participation in daily activities, and diminished quality of life. Despite existing interventions such as exercise programs and pharmacological treatments, challenges such as fatigue, pain, and limited accessibility underscore the need for alternative therapies. Focal vibration therapy (FVT) has shown promise in improving gait, reducing spasticity, and enhancing mobility in people with MS (PwMS). However, further research is required to evaluate its long-term feasibility and optimize its parameters. This study examined the feasibility and preliminary efficacy of a home-based four-week wearable FVT device on gait and explored how FVT parameters impact gait and mobility outcomes. In this pilot double-blind randomized controlled trial, 22 PwMS were randomized into control and vibration groups (four FVT groups with varying vibration intensities/durations). Participants wore Myovolt^® vibrators on distal quadricep muscles near the rectus femoris insertion (approximately 2 cm from the medial edge of the patella), gastrocnemius/soleus, and tibialis anterior muscles (10 min/muscle, 3 days/week, 4 weeks). Feasibility was evaluated via adherence and satisfaction (QUEST 2.0, interviews). Gait (3D motion analysis) and mobility (T25FW) were assessed at baseline and post-intervention. Data were analyzed using descriptive/inferential statistics and thematic analysis. Of 22 participants, 17 completed post-intervention (16 intervention, 1 control). Wearable FVT showed promising feasibility, with high satisfaction despite minor adjustability issues. Intervention groups improved gait speed (p = 0.014), stride length (p = 0.004), and ankle angle (p = 0.043), but T25FW was unchanged (p > 0.05). High-intensity FVT enhanced knee/hip moments. This study’s results support the feasibility of wearable FVT for home-based management of mobility symptoms in MS with high participant satisfaction and acceptance. Notable gains in gait parameters suggest FVT’s potential to enhance neuromuscular control and proprioception but may be insufficient to lead to mobility improvements. Subgroup analyses highlighted the impact of vibration intensity and duration on knee joint mechanics, emphasizing the need for personalized dosing strategies. Challenges included participant retention in the control group and burdensome biomechanical assessments, which will be addressed in future studies through improved sham devices and a larger sample size. Full article

Background: The iliotibial band (ITB) is an anatomically complex structure with multiple proximal and distal attachments, making its mechanical behavior difficult to interpret. In the study of iliotibial band syndrome (ITBS), prior research has often considered the underlying lateral femoral epicondyle (LFE) as a fixed reference to describe ITB movement during knee flexion, potentially misrepresenting true tissue dynamics. This proof-of-concept study introduces the musculoskeletal advanced transillumination technique (MATT) to visualize and measure LFE displacement relative to the ITB and the tubercule of the ITB (tITB) on the tibia during passive knee flexion. Methods: Un-embalmed donor knees (n = 8) were dissected to expose the ITB and positioned on a device allowing standardized passive motion from 0° to 30°. A trocar was inserted between the femoral epicondyles, and a 300-watt xenon light source illuminated the LFE. Video was recorded with an iPhone 15, and key frames were analyzed using ImageJ Version 1.54i, and a custom Python (Version 3.12.5) script to quantify LFE displacement relative to the ITB and to the tITB. Results: Median absolute LFE displacement from 0° to 30° was 9.18 mm (IQR 7.23–10.95). Between 0° and 30°, the LFE shifted anteriorly by −1.76 mm (IQR −10.28 to −8.72) relative to the anterior border of the ITB, and by 11.26 mm (IQR 8.27 to 26.33) relative to its posterior border. The LFE-tITB distance increased from 51.98 mm (IQR 49.13–52.36) at 0° to 53.66 mm (IQR 50.08–60.11) at 30°, with a median displacement of 3.92 mm (IQR: 2.48–5.73). Conclusions: Musculoskeletal Advance Transillumination Technique (MATT) is a straightforward and reproducible technique that offers direct visualization of the dynamic relationship between a skeletal landmark and myofascial structures, such as the LFE and the ITB. By challenging the assumption that the LFE is a fixed reference point, MATT opens new perspectives for investigating the biomechanical mechanisms underlying conditions like iliotibial band syndrome. Full article

The controlled switching of capacitor banks when properly parameterized brings significant benefits to the bank, circuit breaker, and adjacent equipment by significantly reducing the levels of inrush currents. This article explores and analyzes the waveforms from a circuit breaker equipped with both preinsertion resistors (PIR) and a controlled switching device (CSD), proposing a dynamic approach to determine the better closing times for both the PIR and the main contact of the circuit breaker, thereby reducing inrush current levels and improving system performance and reliability. The study employs a computational tool to identify the circuit breaker’s contacts insertion points, presenting important information such as the best closing instant for the main contact, the determination of preinsertion time, and maximum inrush current peak. The waveforms used in the study originate from both a real power shunt capacitor bank from a Brazilian substation and simulations modeled using the Alternative Transient Program (ATP). This dynamic approach not only reduces inrush current levels, but also contributes to increasing the useful life of the capacitor bank elements, the circuit breaker itself, and neighboring equipment. Full article

Background: Peripherally inserted central catheters (PICCs) are becoming an increasingly utilised alternative to traditional central venous access devices. Their uptake, particularly among oncology patients, is due to their growing ease of access, suitability for medium-term use and perceived safety profile. However, PICCs can be a source of severe and life-threatening complications such as central line-associated bloodstream infection (CLABSI), deep vein thrombosis (DVT), pulmonary embolism (PE), malpositioning, dislodgement, and occlusion. Methods: This narrative was constructed from a literature review of the PubMed database, utilising MESH terms for peripherally inserted central catheters, percutaneous central catheters, PICC, and complications. Randomised controlled trials, systematic reviews, and meta-analyses published between 2015 and 2025 were included. Additional articles were obtained through targeted PubMed searches or from references within previous articles. Results: Major periprocedural complications were seen in 1.1% of PICC insertions, CLABSI in 1.4–1.9%, venous thrombosis embolism (including PE) in 2.3–5.9%, and malpositioning in 7.87%. The overall PICC complication incidence was 9.5–38.6%, which is greater than that of centrally inserted central venous access. A higher BMI, diabetes mellitus, chronic renal failure, and malignancy were the most significant predictive factors for PICC-associated complications. Conclusions: PICC complications are common, occurring more frequently than other forms of central venous access, and may lead to significant morbidity and mortality. Appropriate assessment of patient risk factors and optimisation strategies may reduce complication rates. Full article

Orthodontic mini-implants are well-known anchorage devices and stand out as a particularly effective tool for ensuring maximum anchorage without relying on patient compliance. Therefore, it is necessary to understand what levels of torque strains remain in the physiological limits and can guarantee the stability of these mini-implants. The aim of this study was to investigate and measure the initial and final torque values of orthodontic mini-implants when placed perpendicular to the maxillary and mandibular bone surfaces. In our study, orthodontic mini-implants from different companies were inserted perpendicularly using different insertion torques on the plate of both maxillary and mandibular bones from pig specimens. The torque values were then analyzed. The results of this study highlight the need for continued research to analyze the ideal insertion torque of different types of mini-implants depending on the insertion area, in order to achieve clinical success of mini-implants. Full article

Styles are invasive medical devices that are visible on images and are used in several medical specialties, including cardiology, neurology, orthopaedics, anaesthesia, oto-rhino-laryngology (ENT), and dentistry. With their thin and flexible design, they allow for the optimal positioning and precise guidance of medical devices such as nerve stimulation, defibrillation, electrode positioning, and catheter insertion. Generally, they are made of stainless steel, offering a combination of rigidity and flexibility. The aim of this study is to evaluate the sensitivity of austenitic stainless steel 304L used for the manufacture of J-stylets in uniform, pitting, crevice, and intergranular corrosion. We follow the manufacturing process step by step in order to analyse the risks of corrosion sensitisation and the cumulative effects of various forms of degradation, which could lead to a significant release of metal cations. Another objective of this study is to determine the optimal heat treatment temperature to minimise sensitivity to the intergranular corrosion of 304L steel. Uniform corrosion: Two samples were taken at each stage of the manufacturing process (eight steps in total), in the form of rods. After one hour of immersion, potentiodynamic polarisation curves were plotted up to ±400 mV vs. SCE. A coulometric analysis was also performed by integrating the anode zone between E (i = 0) and +400 mV vs. SCE. The values obtained by integration are expressed as mC/cm². The test medium used was a simulated artificial plasma solution (9 g/L NaCl solution). Intergranular corrosion: (a) Chemical test: Thirty rod-shaped samples were tested, representing the eight manufacturing steps, as well as heat treatments at 500 °C, 620 °C, and 750 °C, in accordance with ASTM A262 (F method). (b) Electrochemical Potentiokinetic Reactivation (EPR) according to ASTM G108–94 (2015). Two samples were tested for each condition: without heat treatment and after treatments at 500 °C, 620 °C, and 750 °C. Release of cations: The release of metal ions was evaluated in the following two media: artificial sweat, according to EN 1811:2011+A1:2015, and bone plasma, according to the Fitton-Jackson and Burks-Peck method. Six samples that had been heat-treated at 500 °C for one hour were analysed. Results, discussions: (a) Analysis of the polarisation curves revealed significant disturbances in the heat treatment steps, as well as the μC/cm² quantities, which were between 150,000 and 400,000 compared to only 40–180 for the other manufacturing steps; (b) Electrochemical Potentiokinetic reactivation (EPR) tests indicated that the temperature of 500 °C was a good choice to limit 304L steel sensitisation in intergranular corrosion; and (c) the quantities of cations released in EN 1811 sweat were of the order of a few μg/cm² week, as for Fe: 2.31, Cr: 0.05, and Ni: 0.12. Full article

Reversible gates theoretically do not result in energy loss during the calculation process. The Toffoli gate is a universal reversible logic gate, and any reversible circuit can be constructed from the Toffoli gate. This paper presents a hybrid electro-optic Toffoli logic that uses an HSPP Switch (hybrid surface plasmon polariton switch), waveguide coupler, and Y-shaped splitter. The hybrid electro-optic Toffoli logic operation is applied via voltage regulation, and the FDTD simulation is used for this research. The modeling and simulation results show that the device’s operating speed is up to 61.62 GHz; the power consumption for transmitting 1 bit is only 13.44 fJ; the average insertion loss is 6.4 dB, and the average extinction ratio of each output port is 19.7 dB. Full article

A highly sensitive Fabry–Pérot interferometer (FPI) is fabricated via symmetric taper fiber cleaving and centered waist-inserted assembly, a design where geometric symmetry is fundamental to the sensor’s performance. The FPI is fabricated by simple and cost-effective techniques, including fiber cleaving, splicing, and tapering. Due to the ultra-long cantilever beam with an effective length of 2.33 mm and the ultra-short Fabry–Pérot (FP) cavity with an actual length of 13.98 μm, the sensor exhibits an ultra-high strain sensitivity of 544.57 pm/με in experimental results. The sensor boasts a small temperature sensitivity of 1.02 pm/°C and a cross-temperature sensitivity of 0.0019 µε/°C in the temperature range of 25–200 °C. Furthermore, the sensor has good stability and repeatability. Owing to the symmetry-enhanced design, simple fabrication process, high strain sensitivity, as well as a stable, linearly proportional response over an extensive strain regime, the device has large potential in various sensing applications. Full article

There are no recorded cases of catheter-induced aortic dissection in pediatric patients. We report a unique case of a pediatric patient with Down syndrome who developed a long-standing dissecting aortic aneurysm. The patient underwent successful stent insertion 10 years after experiencing difficulty retrieving an embolized patent ductus arteriosus device. The Down syndrome presented a complex clinical scenario, making diagnosis challenging due to a lack of cooperation and uncertainty about when the dissection occurred, as symptoms like pain were not reported. Though rare in children, it is vital to recognize procedures such as percutaneous closure of patent ductus arteriosus followed by device retrieval as potential risk factors for aortic dissections in the pediatric population. Full article

The aim of this work is to evaluate the effectiveness of antimicrobial photodynamic therapy (aPDT) against oral MDR (multi-drug-resistant) Candida spp. infections related to orthodontic treatment with palatal expanders through in vitro study. Methods: PDT protocol: Curcumin + H₂O₂ was used as a photosensitizer activated by a 460 nm diode LED lamp, with an 8 mm blunt tip for 2 min in each spot of interest. In vitro simulation: A palatal expander sterile device was inserted into a custom-designed orthodontic bioreactor, realized with 10 mL of Sabouraud dextrose broth plus 10% human saliva and infected with an MDR C. albicans clinical isolate CA95 strain to reproduce an oral palatal expander infection. After 48 h of incubation at 37 °C, the device was treated with the PDT protocol. Two samples before and 5 min after the PDT process were taken and used to contaminate a Petri dish with a Sabouraud field to evaluate Candida spp. CFUs (colony-forming units). Results: A nearly 99% reduction in C. albicans colonies in the palatal expander biofilm was found after PDT. Conclusion: The data showed the effectiveness of using aPDT to treat palatal infection; however, specific patient oral micro-environment reproduction (Ph values, salivary flow, mucosal adhesion of photosensitizer) must be further analyzed. Full article

This paper presents a novel approach employing localized annealing through Joule heating to enhance the performance of Thin-Film Piezoelectric-on-Silicon (TPoS) MEMS resonators that are crucial for applications in sensing, energy harvesting, frequency filtering, and timing control. Despite recent advancements, piezoelectric MEMS resonators still suffer from anchor-related energy losses and limited quality factors (Qs), posing significant challenges for high-performance applications. This study investigates interface modification to boost the quality factor (Q) and reduce the motional resistance, thus improving the electromechanical coupling coefficient and reducing insertion loss. To balance the trade-off between device miniaturization and performance, this work uniquely applies DC current-induced localized annealing to TPoS MEMS resonators, facilitating metal diffusion at the interface. This process results in the formation of platinum silicide, modifying the resonator’s stiffness and density, consequently enhancing the acoustic velocity and mitigating the side-supporting anchor-related energy dissipations. Experimental results demonstrate a Q-factor enhancement of over 300% (from 916 to 3632) and a reduction in insertion loss by more than 14 dB, underscoring the efficacy of this method for reducing anchor-related dissipations due to the highest annealing temperature at the anchors. The findings not only confirm the feasibility of Joule heating for interface modifications in MEMS resonators but also set a foundation for advancements of this post-fabrication thermal treatment technology. Full article