415 results match your criteria: "Rue University[Affiliation]"

Characterization of Human iPSC-derived Spinal Motor Neurons by Single-cell RNA Sequencing.

Neuroscience

December 2020

Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, 3801, rue University, Montreal (Quebec) H3A 2B4, Canada. Electronic address:

Human induced pluripotent stem cells (iPSCs) offer the opportunity to generate specific cell types from healthy and diseased individuals, allowing the study of mechanisms of early human development, modelling a variety of human diseases, and facilitating the development of new therapeutics. Human iPSC-based applications are often limited by the variability among iPSC lines originating from a single donor, as well as the heterogeneity among specific cell types that can be derived from iPSCs. The ability to deeply phenotype different iPSC-derived cell types is therefore of primary importance to the successful and informative application of this technology.

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Pre- and post-synaptic roles for DCC in memory consolidation in the adult mouse hippocampus.

Mol Brain

April 2020

Montréal Neurological Institute, Department of Neurology & Neurosurgery, McGill University, 3801 Rue University, Montréal, Québec, H3A 2B4, Canada.

The receptor deleted in colorectal cancer (DCC) and its ligand netrin-1 are essential for axon guidance during development and are expressed by neurons in the mature brain. Netrin-1 recruits GluA1-containing α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) and is critical for long-term potentiation (LTP) at CA3-CA1 hippocampal Schaffer collateral synapses, while conditional DCC deletion from glutamatergic neurons impairs hippocampal-dependent spatial memory and severely disrupts LTP induction. DCC co-fractionates with the detergent-resistant component of postsynaptic density, yet is enriched in axonal growth cones that differentiate into presynaptic terminals during development.

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Mechanically-induced osteophyte in the rat knee.

Osteoarthritis Cartilage

June 2020

Department Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada; Human Mobility Research Center, Kingston General Hospital, 76 Stuart Street, Kingston, ON, K7L 2V7, Canada; Department of Surgery, Queen's University, Kingston, ON, Canada; Kingston General Hospital, Kingston, ON, Canada; Department of Mechanical and Materials Engineering, Queen's University, Kingston, ON, Canada; School of Computing, Queen's University, Kingston, ON, Canada.

Objectives: Osteophytes are common anatomical signs of advanced osteoarthritis. It remains unclear whether they develop from physio-molecular, and/or mechanical stimuli. This study examined the effects of mechanical impact on the knee joint periosteum leading to osteophyte formation.

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Spin-polarized quantum transport in Si dangling bond wires.

Nanoscale

March 2020

Department of Physics, McGill University, 3600 rue university, Montréal, Québec H3A 2T8, Canada.

We report theoretical modeling of spin-dependent quantum transport properties of dangling bond wires (DBWs) on the Si(100)-2 × 1:H surface. A single spin-polarized dangling bond center (DBC) near the DBW may strongly affect transport as characterized by anti-resonances or dips in the transmission spectra. Such spin-dependent gating can be effective up to a distance of 1.

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Predictive Pattern Classification Can Distinguish Gender Identity Subtypes from Behavior and Brain Imaging.

Cereb Cortex

May 2020

Department of Psychiatry, Psychotherapy and Psychosomatics, Faculty of Medicine, RWTH Aachen, 52074 Aachen, Germany.

The exact neurobiological underpinnings of gender identity (i.e., the subjective perception of oneself belonging to a certain gender) still remain unknown.

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Pluripotent stem cell (PSC)-derived insulin-producing cells are a promising cell source for diabetes cellular therapy. However, the efficiency of the multi-step process required to differentiate PSCs towards pancreatic beta cells is variable between cell lines, batches and even within cultures. In adherent pancreatic differentiation protocols, we observed spontaneous local clustering of cells expressing elevated nuclear expression of pancreatic endocrine transcription factors, PDX1 and NKX6.

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An apparatus based on an atomic force microscope for implementing tip-controlled local breakdown.

Rev Sci Instrum

December 2019

Physics Department, McGill University, 3600 rue University, Montreal, Quebec H3A 2T8, Canada.

Solid-state nanopores are powerful tools for sensing of single biomolecules in solution. Fabrication of solid-state nanopores is still challenging, however; in particular, new methods are needed to facilitate the integration of pores with larger nanofluidic and electronic device architectures. We have developed the tip-controlled local breakdown (TCLB) approach, in which an atomic force microscope (AFM) tip is brought into contact with a silicon nitride membrane that is placed onto an electrolyte reservoir.

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Deep learning segmentation of orbital fat to calibrate conventional MRI for longitudinal studies.

Neuroimage

March 2020

McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, 3801 Rue University, Montreal, QC, H3A 2B4, Canada. Electronic address:

Article Synopsis
  • Conventional MRI has consistent image contrast, but absolute intensity can vary across scans, making quantitative analysis challenging, especially in diseases like multiple sclerosis where both white and gray matter are affected.
  • The study introduces a new method called "image calibration," which aims to eliminate technical artifacts while maintaining important biological differences by using fat segmentation from the eye orbit as a reference tissue.
  • The deep learning approach used for segmentation shows high accuracy compared to human experts and results in better consistency with semi-quantitative imaging than traditional normalization methods, facilitating easier tracking of disease changes over time.
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Biocompatibility and Durability of Diazonium Adhesives on Dental Alloys.

J Prosthodont

March 2020

Faculty of Dentistry, McGill University, Strathcona Anatomy and Dentistry Building, Rue University, Montreal, Quebec, H3A 0C7, Canada.

Purpose: A new type of diazonium-based adhesive has been recently developed by our team to bind dental alloys (Titanium, stainless steel, and cobalt chromium) to dental polymers. Here, we explored the endurance of the resulting adhesive after thermal-cycling and autoclave aging.

Materials And Methods: Polished samples of titanium (Ti), stainless steel (SS) and cobalt chromium (Co-Cr) were coated with a diazonium-based adhesive.

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Detection of CMB-Cluster Lensing using Polarization Data from SPTpol.

Phys Rev Lett

November 2019

Fermi National Accelerator Laboratory, P. O. Box 500, Batavia, Illinois 60510, USA.

We report the first detection of gravitational lensing due to galaxy clusters using only the polarization of the cosmic microwave background (CMB). The lensing signal is obtained using a new estimator that extracts the lensing dipole signature from stacked images formed by rotating the cluster-centered Stokes QU map cutouts along the direction of the locally measured background CMB polarization gradient. Using data from the SPTpol 500  deg^{2} survey at the locations of roughly 18 000 clusters with richness λ≥10 from the Dark Energy Survey (DES) Year-3 full galaxy cluster catalog, we detect lensing at 4.

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The cosmic microwave background (CMB) -mode signal is potentially weaker than the diffuse Galactic foregrounds over most of the sky at any frequency. A common method of separating the CMB from these foregrounds is via pixel-based parametric-model fitting. There are not currently enough all-sky maps to fit anything more than the most simple models of the sky.

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Successive Kinesin-5 Microtubule Crosslinking and Sliding Promote Fast, Irreversible Formation of a Stereotyped Bipolar Spindle.

Curr Biol

November 2019

Department of Biology, McGill University, 1205 Avenue Doctor Penfield, Montreal, QC H3A 1B1, Canada; Integrated Quantitative Biology Initiative, McGill University, 1205 Avenue Doctor Penfield, Montreal, QC H3A 1B1, Canada. Electronic address:

Separation of duplicated spindle poles is the first step in forming the mitotic spindle. Kinesin-5 crosslinks and slides anti-parallel microtubules (MTs), but it is unclear how these two activities contribute to the first steps in spindle formation. In this study, we report that in monopolar spindles, the duplicated spindle poles snap apart in a fast and irreversible step that produces a nascent bipolar spindle.

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New technologies have powered rapid advances in cellular imaging, genomics and phenotypic analysis in life sciences. However, most of these methods operate at sample population levels and provide statistical averages of aggregated data that fail to capture single-cell heterogeneity, complicating drug discovery and development. Here we demonstrate a new single-cell approach based on convex lens-induced confinement (CLiC) microscopy.

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Correction for 'Probing the organization and dynamics of two DNA chains trapped in a nanofluidic cavity' by Xavier Capaldi et al., Soft Matter, 2018, 14, 8455-8465.

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A Non-linear Viscoelastic Model of the Incudostapedial Joint.

J Assoc Res Otolaryngol

February 2020

Department of Biomedical Physics, University of Antwerp, Groenenborgerlaan 171, 2020, Antwerpen, Belgium.

The ossicular joints of the middle ear can significantly affect middle-ear function, particularly under conditions such as high-intensity sound pressures or high quasi-static pressures. Experimental investigations of the mechanical behaviour of the human incudostapedial joint have shown strong non-linearity and asymmetry in tension and compression tests, but some previous finite-element models of the joint have had difficulty replicating such behaviour. In this paper, we present a finite-element model of the joint that can match the asymmetry and non-linearity well without using different model structures or parameters in tension and compression.

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Phase-field crystal for an antiferromagnet with elastic interactions.

Phys Rev E

August 2019

Physics Department, Rutherford Building, 3600 rue University, McGill University, Montréal, Québec, Canada H3A 2T8.

We introduce a model which contains the essential elements to formulate and study antiferromagnetism, using the phase-field crystal framework. We focus on the question of how magneto-elastic coupling could lift the frustration in the two-dimensional hexagonal antiferromagnetic phase. Using simulations we observe a rich variety of different phases stable in this model.

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A robust approach to ab initio cryo-electron microscopy initial volume determination.

J Struct Biol

December 2019

Departament of Anatomy and Cell Biology, McGill University, 3640 Rue University, Montréal, QC H3A 0C7, Canada. Electronic address:

Structural information from macromolecules provides key insights into the way complexes perform their biological functions. The reconstruction process leading to the final three-dimensional (3D) map is iterative and requires an initial volume to prime the refinement procedure. Particle images are aligned to this first reference and subsequently a new map is calculated from these particles.

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Arachidonic acid exacerbates diet-induced obesity and reduces bone mineral content without impacting bone strength in growing male rats.

J Nutr Biochem

November 2019

School of Human Nutrition, McGill University, 21111 Lakeshore Road, Ste-Anne-de-Bellevue, QC, Canada H9X 3V9. Electronic address:

Long-chain polyunsaturated fatty acids modulate bone mass and adipocyte metabolism. Arachidonic acid (AA, C20:4 n-6) is elevated in obesity and postulated to stimulate bone resorption. This study aimed to determine the effect of AA on bone mass, quality, and adiposity in diet-induced obesity during growth.

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Automatic local resolution-based sharpening of cryo-EM maps.

Bioinformatics

February 2020

Biocomputing Unit, National Center for Biotechnology (CSIC), Darwin 3, Campus Univ. Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.

Motivation: Recent technological advances and computational developments have allowed the reconstruction of Cryo-Electron Microscopy (cryo-EM) maps at near-atomic resolution. On a typical workflow and once the cryo-EM map has been calculated, a sharpening process is usually performed to enhance map visualization, a step that has proven very important in the key task of structural modeling. However, sharpening approaches, in general, neglects the local quality of the map, which is clearly suboptimal.

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Long-range electron transfer is a ubiquitous process that plays an important role in electrochemistry, biochemistry, organic electronics, and single molecule electronics. Fundamentally, quantum mechanical processes, at their core, manifest through both electron tunneling and the associated transition between quantized nuclear vibronic states (intramolecular vibrational relaxation) mediated by electron-nuclear coupling. Here, we report on measurements of long-range electron transfer at the interface between a single ferrocene molecule and a gold substrate separated by a hexadecanethiol quantum tunneling barrier.

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Double-wave reentry in excitable media.

Chaos

July 2019

Department of Physiology, McGill University, 3655 Promenade Sir William Osler, Montreal, Quebec H3G 1Y6, Canada.

A monolayer of chick embryo cardiac cells grown in an annular geometry supports two simultaneous reentrant excitation waves that circulate as a doublet. We propose a mechanism that can lead to such behavior. The velocity restitution gives the instantaneous velocity of a wave as a function of the time since the passage of the previous wave at a given point in space.

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Response of mechanically-created neurites to extension.

J Mech Behav Biomed Mater

October 2019

Department of Physics, McGill University, 3600 Rue University, Montréal, Québec, H3A2T8, Canada.

We use micromanipulation techniques and real-time particle tracking to develop an approach to study specific attributes of neuron mechanics. We use a mechanical probe composed of a hollow micropipette with its tip fixed to a functionalized bead to induce the formation of a neurite in a sample of rat hippocampal neurons. We then move the sample relative to the pipette tip, elongating the neurite while simultaneously measuring its tension by optically tracking the deflection of the beaded tip.

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A review of bubble break-up.

Adv Colloid Interface Sci

August 2019

Department of Physics and Mathematics, Nottingham Trent University, Nottingham, UK. Electronic address:

The coalescence and break-up of bubbles are important steps in many industrial processes. To date, most of the literature has been focussed on the coalescence process which has been studied using high speed cinematographic techniques. However, bubble break-up is equally important and requires further research.

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Glass ionomer cements with enhanced mechanical and remineralizing properties containing 45S5 bioglass-ceramic particles.

J Mech Behav Biomed Mater

September 2019

Department of Mechanical, Industrial and Aerospace Engineering (MIAE), Concordia University, Montréal, Quebec, H3G 1M8, Canada. Electronic address:

The clinical applications of glass ionomer cements (GICs) are limited by their relatively poor mechanical properties and insufficient remineralizing capacity. In this study, we developed hybrid GICs with improved mechanical and remineralizing properties via incorporation of an optimum amount (5 wt%) of 45S5 bioglass-ceramic particles. Also, we found that bioglass-ceramic particles with 74% crystallinity best act as both remineralizing and reinforcing agents.

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The extended life expectancy and the raise of accidental trauma call for an increase of osteoarticular surgical procedures. Arthroplasty, the main clinical option to treat osteoarticular lesions, has limitations and drawbacks. In this manuscript, we test the preclinical safety of the innovative implant ARTiCAR for the treatment of osteoarticular lesions.

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