A Traumatic Impact Immediately Changes the Mechanical Properties of Articular Cartilage.

Objective: To investigate whether and how a single traumatic impact changes the mechanical properties of talar articular cartilage.

Design: A marble was placed on the joint surface and a weight was dropped on both medial and lateral caprine talus to create a well-defined single focal impact. The mechanical properties of intact and impacted talar cartilage were measured with a micro-indenter.

Feasibility of Live Video Feed Transmission from Unmanned Aerial Vehicles for Medical Surveillance During the 2022 Montreal Marathon.

Introduction: In recent years, unmanned aerial vehicles (UAVs) have been increasingly used for medical surveillance purposes in mass-gathering events. No studies have investigated the reliability of live video transmission from UAVs for accurate identification of distressed race participants in need of medical attention. The aim of this study was to determine the proportion of time during which live medical surveillance UAV video feed was successfully transmitted and considered of sufficient quality to identify acute illness in runners participating in the 2022 Montreal Marathon (Canada).

Resiliency Intervention for Siblings of Children With Autism Spectrum Disorder: A Randomized Pilot Trial.

Background /objectives: Neurotypical siblings (NT siblings) of children with autism spectrum disorder (ASD) are at elevated risk for emotional distress and adjustment problems. Resiliency is the ability to cope and adapt with ongoing stressors. We conducted a randomized waitlist-controlled pilot trial to examine the feasibility, acceptability, and preliminary efficacy of an adapted virtual mind-body resiliency group intervention for teen NT siblings of children with ASD.

Acceptability of A Virtual Mind-Body Group Intervention for Teen Siblings of Children with Autism Spectrum Disorder.

Teenage siblings of children with autism spectrum disorder (ASD) are at risk of worse mental health outcomes than their peers, yet there have been few interventions focused on improving their psychosocial wellbeing. This study explored the acceptability of an 8-session virtual group mind-body resiliency intervention for teen siblings of children with ASD. We used mixed methods to assess quantitative and qualitative survey results.

Association of Neighborhood Characteristics With Pediatric Asthma.

Objective: To examine associations between neighborhood characteristics and asthma prevalence and severity among low-income children in a large nationally representative sample.

Methods: Data source: 2018 National Survey of Children's Health, limited to low-income children, ages 0-17 years. We grouped parent responses about neighborhood characteristics into 5 scores: neighborhood support, safety, resources and quality, and a total score.

Facilitator Reflections on Shared Expertise and Adaptive Leadership in ECHO Autism: Center Engagement.

Introduction: Project Extension for Community Healthcare Outcomes (ECHO) is used to increase provider capacity in a wide range of health care specialties. ECHO Autism: Center Engagement is a program that promotes improvement in autism care by improving the management of autism care centers. The program's focus brought experienced clinicians together as both facilitators and participants in an ECHO series.

Mechanical alterations of the hippocampus in the APP/PS1 Alzheimer's disease mouse model.

There is increasing evidence of altered tissue mechanics in neurodegeneration. However, due to difficulties in mechanical testing procedures and the complexity of the brain, there is still little consensus on the role of mechanics in the onset and progression of neurodegenerative diseases. In the case of Alzheimer's disease (AD), magnetic resonance elastography (MRE) studies have indicated viscoelastic differences in the brain tissue of AD patients and healthy controls.

Challenges and Growth: Lived Experience of Adolescents and Young Adults (AYA) with a Sibling with ASD.

Adolescent and young adult (AYA) siblings of individuals with autism experience unique challenges that can promote both growth and emotional maladjustment. This study explored sibling and parent reports of siblings' lived experiences and identified learning, stressors, and concerns from those experiences. 20 neurotypical (NT) AYA siblings (ages 13-24), and 21 parents were interviewed.

Viscoelastic properties of white and gray matter-derived microglia differentiate upon treatment with lipopolysaccharide but not upon treatment with myelin.

Background: The biomechanical properties of the brain have increasingly been shown to relate to brain pathology in neurological diseases, including multiple sclerosis (MS). Inflammation and demyelination in MS induce significant changes in brain stiffness which can be linked to the relative abundance of glial cells in lesions. We hypothesize that the biomechanical, in addition to biochemical, properties of white (WM) and gray matter (GM)-derived microglia may contribute to the differential microglial phenotypes as seen in MS WM and GM lesions.

Emergency Department Utilization of Adolescents and Young Adults with Autism Spectrum Disorder.

This study examined emergency department (ED) utilization by adolescents and young adults, 12-30 years of age (AYA) with autism spectrum disorder (ASD) using the 2016 Healthcare Cost and Utilization Project/National Emergency Department Sample (HCUP/NEDS). We investigated the principal reason for an ED visit, presence of an ambulatory care sensitive condition (ACSC), and likelihood of hospital admission following ED encounter in ASD and Non-ASD cohorts. The ASD cohort had a higher proportion of ED visits for ACSC diagnoses as compared to the Non-ASD cohort.

In vivo characterization of chick embryo mesoderm by optical coherence tomography-assisted microindentation.

Embryos are growing organisms with highly heterogeneous properties in space and time. Understanding the mechanical properties is a crucial prerequisite for the investigation of morphogenesis. During the last 10 years, new techniques have been developed to evaluate the mechanical properties of biological tissues in vivo.

Indentation probe with optical fibre array-based optical coherence tomography for material deformation.

We present a new optomechanical probe for mechanical testing of soft matter. The probe consists of a micromachined cantilever equipped with an indenting sphere, and an array of 16 single-mode optical fibres, which are connected to an optical coherence tomography (OCT) system that allows subsurface analysis of the sample during the indentation stroke. To test our device and its capability, we performed indentation on a PDMS-based phantom.

Viscoelastic mapping of mouse brain tissue: Relation to structure and age.

There is growing evidence that mechanical factors affect brain functioning. However, brain components responsible for regulating the physiological mechanical environment are not completely understood. To determine the relationship between structure and stiffness of brain tissue, we performed high-resolution viscoelastic mapping by dynamic indentation of the hippocampus and the cerebellum of juvenile mice brains, and quantified relative area covered by neurons (NeuN-staining), axons (neurofilament NN18-staining), astrocytes (GFAP-staining), myelin (MBP-staining) and nuclei (Hoechst-staining) of juvenile and adult mouse brain slices.

Clinical characteristics of patients from Quebec, Canada, with Morquio A syndrome: a longitudinal observational study.

Background: Morquio A syndrome is a rare, autosomal recessive, progressively debilitating disorder, with multi-system impairments and high medical burden. Quebec, Canada has a large Morquio A population, which is considered unique due to the presence of founder pathogenic variants. The objectives of this study were to document the genetic and clinical heterogeneity of patients with Morquio A in Quebec, to better characterize the phenotype of those with the French Canadian founder pathogenic variant (NM_000512.

Toward clinical elastography of dermal tissues: A medical device to probe skin's elasticity through suction, with subsurface imaging via optical coherence tomography.

The mechanical behavior of dermal tissues is unarguably recognized for its diagnostic ability and in the last decades received a steadily increasing interest in dermatology practices. Among the various methods to investigate the mechanics of skin in clinical environments, suction-based ones are especially noteworthy, thanks to their qualities of minimal invasiveness and relative simplicity of setups and data analysis. In such experiments, structural visualization of the sample is highly desirable, both in its own right and because it enables elastography.

Dynamic indentation reveals differential viscoelastic properties of white matter versus gray matter-derived astrocytes upon treatment with lipopolysaccharide.

Astrocytes in white matter (WM) and gray matter (GM) brain regions have been reported to have different morphology and function. Previous single cell biomechanical studies have not differentiated between WM- and GM-derived samples. In this study, we explored the local viscoelastic properties of isolated astrocytes and show that astrocytes from rat brain WM-enriched areas are ~1.

Mapping the mechanical properties of paintings via nanoindentation: a new approach for cultural heritage studies.

A comprehensive understanding of the behaviour of the heterogenous layers within the paint stratigraphies in historical paintings is crucial to evaluate their long term stability. We aim to refine nanoindentation as a new tool to investigate the mechanical behaviour of historical oil paints, by adapting the probes and the protocol already used in biomechanical research on soft tissues. The depth-controlled indentation profile performed with a spherical probe provides an evaluation of the non-linear viscoelastic behaviour of the individual layers in paint at local scale.

Photoacoustic spectroscopy for gas sensing: A comparison between piezoelectric and interferometric readout in custom quartz tuning forks.

We report on a comparison between piezoelectric and interferometric readouts of vibrations in quartz tuning forks (QTFs) when acting as sound wave transducers in a quartz-enhanced photoacoustic setup (QEPAS) for trace gas detection. A theoretical model relating the prong vibration amplitude with the QTF prong sizes and electrical resistance is proposed. To compare interferometric and piezoelectric readouts, two QTFs have been selected; a tuning fork with rectangular-shape of the prongs, having a resonance frequency of 3.

Investigating the Effects of Mechanical Stimulation on Retinal Ganglion Cell Spontaneous Spiking Activity.

Mechanical forces are increasingly recognized as major regulators of several physiological processes at both the molecular and cellular level; therefore, a deep understanding of the sensing of these forces and their conversion into electrical signals are essential for studying the mechanosensitive properties of soft biological tissues. To contribute to this field, we present a dual-purpose device able to mechanically stimulate retinal tissue and to record the spiking activity of retinal ganglion cells (RGCs). This new instrument relies on combining ferrule-top micro-indentation, which provides local measurements of viscoelasticity, with high-density multi-electrode array (HD-MEAs) to simultaneously record the spontaneous activity of the retina.

Micro-indentation and optical coherence tomography for the mechanical characterization of embryos: Experimental setup and measurements on chicken embryos.

The investigation of the mechanical properties of embryos is expected to provide valuable information on the phenomenology of morphogenesis. It is thus believed that, by mapping the viscoelastic features of an embryo at different stages of growth, it may be possible to shed light on the role of mechanics in embryonic development. To contribute to this field, we present a new instrument that can determine spatiotemporal distributions of mechanical properties of embryos over a wide area and with unprecedented accuracy.

Immersion photoacoustic spectrometer (iPAS) for arcing fault detection in power transformers.

We report on the development of the first immersion photoacoustic spectrometer (iPAS) for arcing fault detection in power transformers. The spectrometer consists of a detection system and an all-optical photoacoustic sensing head mounted inside a small permeable chamber where dissolved diffuses while the transformer oil is kept out. Our all-optical iPAS sensor can be placed directly inside an oil bath and measure dissolved with the sensitivity and linearity needed for in situ arcing fault detection.

A fiber-tip photoacoustic sensor for in situ trace gas detection.

Most trace gas detection methods developed so far largely rely on active sampling procedures, which are known to introduce different kinds of artifacts. Here, we demonstrate sampling-free in situ trace gas detection in millimeter scale volumes with fiber coupled cantilever enhanced photoacoustic spectroscopy. Our 2.

70 μm diameter optical probe for common-path optical coherence tomography in air and liquids.

We investigate and validate a novel method to fabricate ultrathin optical probes for common-path optical coherence tomography (CP-OCT). The probes are obtained using a 65 μm barium titanate microsphere inserted into an inward concave cone chemically etched at the end of a single-mode fiber. We demonstrate that the high refractive index (n=1.