Citations

Wearable sensors are increasingly used to monitor physical activity, yet low-power devices often rely on data aggregation to conserve battery life, potentially impacting measurement accuracy. This study evaluates the performance of a new low-power wearable (LPW), designed for monitoring steps across multiple months in a free-living environment, compared to a research-grade sensor (RGS) that collects raw acceleration data, with a focus on how different aggregation intervals impact step count accuracy. Thirty-two participants wore both sensors over two days, with LPW data collected in 10 min, 1 min, or 10 s aggregation periods (APs). Sensitivity and specificity of wear time detection were high across all APs (0.96 and 0.98, respectively). While total daily step count error did not differ significantly between APs, the 10 min AP exhibited greater undercounting and wider limits of agreement, especially in APs containing more than 40 steps. These findings suggest that although AP does not affect total daily step count, it influences the accuracy and variability of more granular data windows. Aggregating step counts over longer intervals may obscure short, fragmented bouts common in daily activity, leading to underestimation of steps. Optimizing APs and sensor settings is critical for improving accuracy in low-power wearables used outside laboratory settings.

ABSTRACT Cues such as fast‐food advertisements associated with food can provoke food cravings which may lead to unhealthy overeating. To effectively control such cravings, we need to better understand the factors that reduce food cue reactivity and reveal corresponding ‘anti‐craving’ brain mechanisms. We previously reported that access to environmental enrichment (EE), that provides cognitive and physical stimulation in mice, reduced cue‐evoked sucrose seeking and prelimbic cortex (PL) neuronal reactivity. To date, the phenotype of PL neurons that undergo EE‐induced adaptations has not been fully elucidated. Therefore, we used brain slice electrophysiology to investigate how EE modulated intrinsic excitability in the general population of PL interneurons and pyramidal cells. Additionally, we used retrograde tracing and the neuronal activity marker ‘Fos’ to investigate how EE modulated cue‐evoked recruitment of pyramidal cells projecting to the paraventricular nucleus of the thalamus (PVT) and nucleus accumbens core (NAc). Before the cue‐evoked sucrose seeking test, EE increased the general, baseline excitability of inhibitory interneurons, but not pyramidal cells. During cue‐evoked sucrose seeking, EE selectively suppressed recruitment of corticothalamic (PL → PVT), but not corticoaccumbens (PL → NAc), projections. Collectively, these findings advance our understanding of EE's ‘anti–food‐seeking’ actions by demonstrating both cell type‐specific increases in local inhibitory tone and circuit‐specific modulation of PL output pathways.

Abstract Atraumatic and localized drug delivery to the vascular endothelium remains a critical unmet need in interventional medicine, with major implications for the management of arterial and venous diseases. Current approaches, such as drug-eluting stents and drug-coated balloons, combine mechanical revascularization with local drug release but frequently denude the endothelium and injure vessel walls, leading to restenosis, thrombosis, and chronic inflammatory repair cycles that severely limit long-term outcomes. Here, we present EndoBot, a soft, untethered millirobot designed for atraumatic navigation and targeted endovascular drug delivery during physiologic blood flow. EndoBot employs magnetically actuated corkscrew propulsion and mechanically adaptive surface crawling to maintain low radial pressure (<1 kPa) and preserve endothelial integrity. Its feasibility is established in arterial and venous phantom models, ex vivo human umbilical veins under normothermic perfusion, and in vivo rat inferior vena cava, all under clinical fluoroscopic guidance using a human-scale magnetic manipulation system. Despite periodic vessel motion, compression, and geometric irregularities, EndoBot maintains stable, mechanically adaptive navigation without endothelial injury. Under real-time fluoroscopic imaging, we identify key challenges and showcase clinically feasible strategies for 3D localization and tracking, overcoming intrinsic depth limitations of 2D clinical imaging. The device can be deployed and retrieved through standard vascular sheaths and remains stable under supraphysiologic arterial and venous flow conditions (flow rate >100 mL min-1; flow velocity >155 cm s-1, shear stress >10 Pa). Blood-compatibility testing demonstrates no increase in coagulation tendency and minimal hemolysis (<0.01%) during magnetic actuation. For drug delivery, EndoBot employs a novel endoluminal painting-based technique that transfers a hydrophobic and flow-resistant coating directly onto the inner vessel surface. This method ensures uniform deposition of a biodegradable drug depot without generating fragments larger than typical capillary diameters (>10 mm). By enabling local, atraumatic drug delivery without compromising vessel wall integrity, EndoBot first time demonstrates a translationally viable platform for exploring effectiveness in preventive interventions in early-stage vascular disease and for adjunctive therapies in advanced disease stages.

Abstract Background The RefleXion X1 is a novel PET/CT‐guided ring gantry linac that introduces unique geometry and workflow compared to conventional systems. Existing QA guidelines (AAPM TG‐142, 148, 306) cover standard linacs and tomotherapy but do not address this platform's needs. Therefore, an automated daily QA solution is required to ensure accurate output, imaging guidance, and couch positioning, which motivated the development and evaluation of the workflow presented in this study. Purpose To develop and evaluate an automated, efficient, and comprehensive daily quality assurance (QA) workflow for a novel PET/CT‐guided ring gantry linear accelerator (RefleXion X1), incorporating tests for dosimetry, imaging guidance, and couch positioning accuracy. Methods An IMRT QA plan was designed following the CT scan of the TomoDose 2D diode detector array (Sun Nuclear, Melbourne, FL) within the RefleXion treatment planning system (TPS). Several spherical targets of varying sizes were contoured to conform the dose distribution to these targets and evaluate beam output, laser localization, profile constancy, and CT‐MV isocenter coincidence. Linear models correlating spatial location of dose peak with intentional shifts in different directions were developed and integrated into an in‐house analysis software, iQA, written in C#. The software was validated for robustness and successfully implemented in clinical practice. Results Validation with 42 intentional shifts showed submillimeter accuracy, with mean deviations of 0.2 mm (X), 0.1 mm (Y), and 0.79 mm (Z), and R 2 values ≥ 0.98. Over 1 year, daily QA data showed stable output constancy (1.006 ± 0.016), left/right target dose constancy (1.007 ± 0.005 and 0.996 ± 0.004), and consistent CT‐MV isocenter offsets (–0.335 ± 0.23 mm in X, 0.19 ± 0.19 mm in Y, and –0.544 ± 0.36 mm in Z). The software also detected a gradual output drift in between, prompting a timely linac adjustment. Conclusion This fully automated, single‐delivery QA workflow enables efficient and robust evaluation of multiple IGRT performance parameters. It improves standardization, reduces human error, and reliably monitors long‐term machine stability. The tools and methodology may be adopted by other clinics seeking a practical and automated daily QA solution. Future developments will focus on incorporating PET QA and rotational couch validations to further enhance the system's comprehensiveness and adaptability.

Background Preclinical studies demonstrate the benefits of ultra‐high dose‐rate (FLASH) radiation, reducing normal tissue toxicity while maintaining tumoricidal effects. Proton FLASH (pFLASH) studies typically use transmission beams, missing the normal tissue‐sparing advantage of the spread‐out Bragg peak (SOBP). Purpose This study aims to propose and implement a series of modifications to enable a clinical Mevion S250i gantry‐mounted synchrocyclotron to deliver pFLASH within the SOBP of the proton beam. Methods A clinical synchrocyclotron was modified to enable FLASH proton beam delivery using the Mevion FLASH accessory kit, a commercially available tool that allows for the delivery of a single spot SOBP at FLASH dose rates. To ensure accurate beam monitoring, a Faraday cup was utilized to measure the integral charge per delivery at different dose rates and calibrate the FLASH transmission ion chamber (FLASHTic), which is integrated in the FLASH accessory mount attached to the nozzle of the gantry. The FLASHTic was specifically designed to prevent saturation at the dose rates associated with FLASH. To generate the desired single spot SOBP, boron carbide absorbers, a range modulating hole filter, and an 11‐mm‐diameter circle brass aperture were employed on the FLASH nozzle mount. Results The results indicate that the FLASHTic measurements demonstrated a strong correlation with the Faraday cup post calibration, suggesting that the FLASHTic can be effectively utilized for both monitoring and terminating the proton beam. The 80%–80% width of the SOBP was 2.01 cm. The peak dose rate at the SOBP proximal peak reached 105.03 Gy/s, with an average of 96.18 Gy/s over five days. Transitioning between FLASH and clinical mode required less than one hour without affecting the clinical beam. Conclusions The commissioning of a 230 MeV proton synchrocyclotron for SOBP FLASH delivery was achieved, providing a platform for preclinical small animal studies on pFLASH effects.

Aims Arthrofibrosis affects a notable percentage of patients after total knee arthroplasty (TKA). Elevated serum mast cell tryptase (SMCT) levels have been linked to fibrosis, suggesting that SMCT could serve as a biomarker for arthrofibrosis. As such, the aims of this study were to assess SMCT levels in TKA patients, and their possible association with arthrofibrosis and clinical outcomes in a prospective clinical trial. Methods We conducted a prospective study involving 219 patients undergoing primary TKA at a single academic medical centre between January 2018 and December 2022. SMCT levels were measured preoperatively, immediately postoperatively, and at six weeks, three months, and one year postoperatively. Secondary outcomes included revision rates, complications, and Knee Society Scores (KSSs). Allergic and inflammatory conditions were assessed for their influence on SMCT levels. Results At one year postoperatively, eight patients had developed arthrofibrosis (4%), and three (1.5%) had undergone manipulation under anaesthesia. The mean preoperative SMCT level was 5.6 µg/L (SD 3.4), which decreased significantly to 4.1 µg/L (SD 2.7) immediately postoperatively (p < 0.001). At six weeks the mean SMCT level was 6.4 µg/l (SD 4.1), and was 6.1 µg/l at both three months (SD 4.1) and one year (SD 4.0). Elevated preoperative SMCT levels were not significantly associated with the risk of arthrofibrosis development (OR 3; p = 0.370), nor were immediate postoperative levels (OR 2; p = 0.754) or those at six weeks (OR 1; p = 0.989). Of note, elevated SMCT levels at three months (OR 5; 95% CI 0.4 to 64; p = 0.191) and one year (OR 13; 95% CI 1 to 232; p = 0.077) trended toward an increased risk of arthrofibrosis development, without reaching significance. Conclusion In patients undergoing TKA, with the numbers included in this study, there was no significant difference in SMCT levels between patients who did and did not develop arthrofibrosis at any timepoint. However, there was a trend towards elevated SMCT levels at three months and one year in those who developed arthrofibrosis, which merits further study. Cite this article: Bone Joint Res 2025;14(11):1045–1052.

Purpose: The purpose of this study was to compare the height of velopharyngeal (VP) closure in relation to the palatal plane between individuals with velopharyngeal insufficiency (VPI) with or without cleft palate and individuals without cleft palate and with normal speech, considering the effects of age and sex. Method: Magnetic resonance imaging was used to analyze the height of VP closure in the midsagittal view during phonation of /i/ and /s/ sounds among 105 individuals with VPI and 45 individuals without cleft palate and normal speech. Results: Independent-samples t tests demonstrated that individuals with VPI display a significantly lower mean height of VP closure (3.7 mm) compared to individuals without cleft palate and normal speech during phonation of /i/ and /s/ sounds ( p < .001). Analysis of variance was used to evaluate the impact of age and sex on the height of VP closure. Significant differences were observed between the height of VP closure in individuals with VPI and those without cleft palate and normal speech across the age span during the production of /i/ and /s/ sounds. However, nonsignificant differences were found between the height of VP closure in males and females of the VPI group and those without cleft palate and normal speech during the production of these sounds. Conclusions: The results revealed the variations of the height of VP closure in relation to the palatal plane. These findings provide insights into the presurgical planning for individuals with VPI undergoing palatal surgeries, especially the location of pharyngeal flap insertion.