35 research outputs found
The Regenerative Effect of Trans-spinal Magnetic Stimulation After Spinal Cord Injury: Mechanisms and Pathways Underlying the Effect
International audienceAbstract Spinal cord injury (SCI) leads to a loss of sensitive and motor functions. Currently, there is no therapeutic intervention offering a complete recovery. Here, we report that repetitive trans-spinal magnetic stimulation (rTSMS) can be a noninvasive SCI treatment that enhances tissue repair and functional recovery. Several techniques including immunohistochemical, behavioral, cells cultures, and proteomics have been performed. Moreover, different lesion paradigms, such as acute and chronic phase following SCI in wild-type and transgenic animals at different ages (juvenile, adult, and aged), have been used. We demonstrate that rTSMS modulates the lesion scar by decreasing fibrosis and inflammation and increases proliferation of spinal cord stem cells. Our results demonstrate also that rTSMS decreases demyelination, which contributes to axonal regrowth, neuronal survival, and locomotor recovery after SCI. This research provides evidence that rTSMS induces therapeutic effects in a preclinical rodent model and suggests possible translation to clinical application in humans
Casimir-Polder force fluctuations as spatial probes of dissipation in metals
We study the spatial fluctuations of the Casimir-Polder force experienced by
an atom or a small sphere moved above a metallic plate at fixed separation
distance. We demonstrate that unlike the mean force, the magnitude of these
fluctuations crucially relies on the relaxation of conduction electron in the
metallic bulk, and even achieves values that differ by orders of magnitude
depending on the amount of dissipation. We also discover that fluctuations
suffer a spectacular decrease at large distances in the case of nonzero
temperature.Comment: 6 pages, 5 figure
Probing the Casimir force with optical tweezers
We propose to use optical tweezers to probe the Casimir interaction between
microspheres inside a liquid medium for geometric aspect ratios far beyond the
validity of the widely employed proximity force approximation. This setup has
the potential for revealing unprecedented features associated to the
non-trivial role of the spherical curvatures. For a proof of concept, we
measure femtonewton double layer forces between polystyrene microspheres at
distances above nm by employing very soft optical tweezers, with
stiffness of the order of fractions of a fN/nm. As a future application, we
propose to tune the Casimir interaction between a metallic and a polystyrene
microsphere in saline solution from attraction to repulsion by varying the salt
concentration. With those materials, the screened Casimir interaction may have
a larger magnitude than the unscreened one. This line of investigation has the
potential for bringing together different fields including classical and
quantum optics, statistical physics and colloid science, while paving the way
for novel quantitative applications of optical tweezers in cell and molecular
biology.Comment: 7 pages, 5 figure
Purification and Characterization of Mouse Olfactory Ensheathing Cells and Their Potential Use for Therapy in Amyotrophic Lateral Sclerosis (ALS)
A recombinase-mediated system for elimination of antibiotic resistance gene markers from genetically engineered Bacillus thuringiensis strains
Proposal to measure the Gravitational Behaviour of Antihydrogen at Rest
We propose an experiment to measure the free fall acceleration of neutral antihydrogen atoms in order to test the Weak Equivalence Principle. The originality of this path is to first produce the antihydrogen ion Hbar+ (or anti H-). The ion is formed through two charge exchange processes involving the interaction of an antiproton with positronium to produce antihydrogen, followed by the interaction of this atom with positronium. The ion is then sympathetically cooled with laser cooled Be+ ions down to ÎĽK temperatures (i.e. m/s velocities). The excess positron can then be laser detached in order to recover the neutral antihydrogen atom. The laser pulse will give the start time for the antihydrogen free fall measurement. The stop will be determined by the detection of the charged pions coming from the annihilation of the antiprotons on a plate placed at a known distance from the initial position of the atoms. From the free fall time and distance one will can extract the value of g. Our goal is a measurement at the level of 1%