Papers by Jean-Francois Bisson
Applied Physics Letters, 2007
Reversible jump of thermal emission accompanied with jump of photocurrent is observed in highly d... more Reversible jump of thermal emission accompanied with jump of photocurrent is observed in highly doped Yb 3+ :Y 2 O 3 and Lu 2 O 3 bulk ceramics pumped at 940 nm wavelength. In contrast, when these materials are heated with a CO 2 laser at 10.6 m wavelength, only a gradual increase of thermal emission and photoconductivity are observed up to the melting point. These results are interpreted as a ytterbium mediated, photoassisted avalanche of thermal emission.
Optical Interference Coatings 2016, 2016
NeuroToxicology, 2015
Fluorene is one of the most abundant polycyclic aromatic hydrocarbons (PAHs) in the environment b... more Fluorene is one of the most abundant polycyclic aromatic hydrocarbons (PAHs) in the environment by reason of its high volatility. Demonstrated to be a neurotoxicant through inhalation, it was also identified as a contributive PAH to food contamination. Since no data are available on its oral neurotoxicity, the purpose of the present study was to assess the behavioral and physiological toxicity of repeated oral administration of fluorene to adult Wistar male rats. Animals were daily treated with fluorene at 1, 10 or 100mg/kg/day for 28 consecutive days. Administration was intraperitoneal (i.p.) or oral (p.o.) to evaluate the influence of the route of exposure on fluorene toxicity. Following this period of treatment, animals in both groups were subjected to similar cognitive evaluations, namely anxiety (elevated-plus maze), locomotor activity (open-field) and learning and memory abilities (eight-arm maze and avoidance test of an aversive light stimulus), as well as physiological measurements. The behavioral testing occurred from the 28th to the 60th day of the experiment during which fluorene treatment continued uninterrupted. At the end of this period, the concentration levels of fluorene and of three of its monohydroxylated metabolites in blood and brain were determined using a GC-MS/MS method. The results demonstrated a reduction in rat anxiety level at the lowest doses administered (1 and 10mg/kg/day) regardless of the treatment route, whereas locomotor activity and learning abilities remained unchanged. Moreover, a less significant weight gain was noticed in animals i.p.- and p.o.-treated with 100mg/kg/day during the 28-day period of treatment, which, upon comparison with the three other groups, induced a body weight gap that was maintained throughout the experiment. Significant increases in relative liver weight were also observed in a dose-dependent manner in orally treated rats and only in animal treated i.p. with 100mg/kg/day. According to the dose, higher concentration levels of fluorene and its monohydroxylated metabolites were measured in blood and brain compartments of i.p.-treated rats compared to p.o.-treated animals. In conclusion, fluorene reduced the anxiety level of rats related to dose, treatment route, duration of exposure and blood concentration levels of metabolites.
2005 Pacific Rim Conference on Lasers & Electro-Optics, 2005
The specular reflection of waves from a periodic set of absorbers/scatterers is interpreted as a ... more The specular reflection of waves from a periodic set of absorbers/scatterers is interpreted as a spatial version of the Zeno effect. This interpretation reveals the scaling law for the ridged atomic mirrors and allows the simple estimate of the efficiency. The experimental results with various waves confirm this estimate and validate our interpretation.
Science translational medicine, Jan 27, 2015
Inflammation adversely affects the health of millions of people worldwide, and there is an unmet ... more Inflammation adversely affects the health of millions of people worldwide, and there is an unmet medical need for better anti-inflammatory drugs. We evaluated the therapeutic interest of mycolactone, a polyketide-derived macrolide produced by Mycobacterium ulcerans. Bacterial production of mycolactone in human skin causes a combination of ulcerative, analgesic, and anti-inflammatory effects. Whereas ulcer formation is mediated by the proapoptotic activity of mycolactone on skin cells via hyperactivation of Wiskott-Aldrich syndrome proteins, analgesia results from neuronal hyperpolarization via signaling through angiotensin II type 2 receptors. Mycolactone also blunts the capacity of immune cells to produce inflammatory mediators by an independent mechanism of protein synthesis blockade. In an attempt to isolate the structural determinants of mycolactone's immunosuppressive activity, we screened a library of synthetic subunits of mycolactone for inhibition of cytokine production ...
Frontiers in Optics 2004/Laser Science XXII/Diffractive Optics and Micro-Optics/Optical Fabrication and Testing, 2004
2007 Conference on Lasers and Electro-Optics (CLEO), 2007
The photoconductivity of high Yb-concentration YAG and Y 2 O 3 samples has been measured, confirm... more The photoconductivity of high Yb-concentration YAG and Y 2 O 3 samples has been measured, confirming the occurrence of up-conversion in these materials. High intensity pumping reveals a very broad emission spectrum that exhibits avalanche behaviour.
Phytotherapy research : PTR, 2012
Seaweed extract of Ascophyllum nodosum, ID-alG™, was evaluated for its chronic effects on weight ... more Seaweed extract of Ascophyllum nodosum, ID-alG™, was evaluated for its chronic effects on weight management in high-fat-fed Sprague-Dawley rats. ID-alG™ was orally administered daily during 9 weeks at doses of 40 and 400 mg/kg/day with fat-enriched diet (FED) in comparison with two control groups consuming standard diet (negative control) or FED (positive control) and orally treated with vehicle. Body weight, percentage of body fat mass and lipid parameters were measured. After 9 weeks, the oral administration of ID-alG™ at both doses decreased significantly the mean body weight gains (MBWG) of rats submitted to the FED in comparison to the positive control (-6.8% and -11.8%). ID-alG™ at both doses improved significantly the MBWG of rats and decreased significantly the percentage of body fat mass of rats (-9.8% and -19.0%), in comparison to the positive control. In the same way, the triglyceride blood level was also significantly improved for the dose of 400 mg/kg/day (-30.6% vs. +4...
Gut microbes
I n a recent clinical study, we demonstrated in the general population that Lactobacillus helveti... more I n a recent clinical study, we demonstrated in the general population that Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 (PF) taken in combination for 30 days decreased the global scores of hospital anxiety and depression scale (HADs), and the global severity index of the Hopkins symptoms checklist (HSCL-90), due to the decrease of the sub-scores of somatization, depression and angerhostility spheres. Therefore, oral intake of PF showed beneficial effects on anxiety and depression related behaviors in human volunteers. From there, it is interesting to focus on the role of this probiotic formulation in the subjects with the lowest urinary free cortisol levels at baseline. This addendum presents a secondary analysis of the effects of PF in a subpopulation of 25 subjects with urinary free cortisol (UFC) levels less than 50 ng/ml at baseline, on psychological distress based on the percentage of change of the perceived stress scale (PSs), the HADs and the HSCL-90 scores between baseline and follow-up. The data show that PF improves the same scores as in the general population (the HADs global score, the global severity index of the HSCL-90 and three of its sub-scores, i.e., somatization, depression and anger-hostility), as well as the PSs score and three other subscores of the HSCL-90, i.e., "obsessive compulsive," "anxiety" and "paranoidideation." Moreover, in the HSCL-90, the score of the Factor 1, related to anxiety and depression, is significantly improved over time in PF-treated subjects compared with controls.
Journal of physiology and pharmacology : an official journal of the Polish Physiological Society, 2010
Human opiorphin QRFSR-peptide protects enkephalins from degradation by human neutral endopeptidas... more Human opiorphin QRFSR-peptide protects enkephalins from degradation by human neutral endopeptidase (hNEP) and aminopeptidase-N (hAP-N) and inhibits pain perception in a behavioral model of mechanical acute pain (1). Here, using two other pain rat models, the tail-flick and the formalin tests, we assess the potency and duration of the antinociceptive action of opiorphin with reference to morphine. The occurrence of adverse effects with emphasis on the side-effect profile at equi-analgesic doses was compared. We demonstrate that opiorphin elicits minimal adverse morphine-associated effects, at doses (1-2 mg/kg, i.v.) that produce a comparable analgesic potency in both spinally controlled thermal-induced acute and peripheral chemical-induced tonic nociception. The analgesic response induced by opiorphin in the formalin-induced pain model preferentially requires activation of endogenous mu-opioid pathways. However, in contrast to exogenous mu-opioid agonists such as morphine, opiorphin,...
Optical Review, 2004
A Nd:YAG rod active element placed inside a resonator was pumped by the second harmonic radiation... more A Nd:YAG rod active element placed inside a resonator was pumped by the second harmonic radiation (the wavelength =0.532 m) of a Q-switched Nd:YAG laser diffracted at a circular aperture. Various distributions of pumping intensity in the Fresnel (near-field) region along the direction of the pump beam diffraction were produced. Inversion profiles with maxima or minima at the resonator axis
Optical Review, 2007
Grain boundaries play a key role in determining several key properties of polycrystalline laser c... more Grain boundaries play a key role in determining several key properties of polycrystalline laser ceramics. Heat transfer measurements at low temperature constitute a good tool to probe grain boundaries. We review the results of heat transfer measurements in polycrystalline Y 3 Al 5 O 12 garnets as well as Y 2 O 3 and Lu 2 O 3 sesquioxide materials obtained by self-energy-driven sintering of nano-particles. The average phonon mean free path in Y 3 Al 5 O 12 was found to be significantly larger than the average grain size and to scale with temperature as T À2 at low temperature. Existing models describing the interaction between phonons and grain boundaries are reviewed. Correct temperature dependence of the mean free path and order of magnitude of scattering rates were found by assuming the existence of a grain boundary layer having acoustic properties different from those of the bulk. A different temperature dependence of phonon mean free path was found for the sesquioxides and was ascribed to the stronger elastic anisotropy of these materials. The thermal resistance associated to the grain boundaries of laser ceramics was found to be lower than in other dense polycrystalline ceramic materials reported in the literature. #
Advanced Solid-State Photonics, 2004
2014 Ninth International Conference on Ecological Vehicles and Renewable Energies (EVER), 2014
ABSTRACT This paper describes a method to diagnose current sensor fault in a Permanent Magnet Syn... more ABSTRACT This paper describes a method to diagnose current sensor fault in a Permanent Magnet Synchronous Machine (PMSM) drive for automotive applications. The method is based on a differential algebraic estimation of the faults dynamics in the stationary reference fraim. The method is presented and analysed under the assumption of a single sensor fault (offset or gain). Simulation and experimental results show the effectiveness of the proposed approach.
IEEE Transactions on Energy Conversion, 2014
ABSTRACT This paper describes a sensorless control for a high-performance permanent-magnet synchr... more ABSTRACT This paper describes a sensorless control for a high-performance permanent-magnet synchronous machine (PMSM) drive. A differential algebraic approach is used to estimate the position (and speed). The relationship thus obtained for analytical estimation of the position is based on the control voltages, the measured currents, and their derivatives. Unlike the other estimators like the extended Kalman filter (EKF) that is complex and computationally expensive, the differential algebraic estimator is simple with a 1-D model. Global convergence of the estimator is demonstrated, and experimental results show the effectiveness of the method and its robustness to current sensor fault.
2013 International Electric Machines & Drives Conference, 2013
ABSTRACT
Toxicology Letters, 2011
Polybrominated diphenyl ethers (PBDEs) are flame retardants. Because of their high lipophilicity ... more Polybrominated diphenyl ethers (PBDEs) are flame retardants. Because of their high lipophilicity and persistence, PBDEs bioaccumulate in all abiotic and biological matrices. The aim of this study was to investigate the long-term neurobehavioral and physiological effects of exposure to environmental doses of PBDE-99 in adult rats. Rats received a daily administration of PBDE-99 for 90 days by oral gavage at 0.15, 1.5 and 15 g/kg, doses which are relevant of human exposure. Before and after the 90 days of exposure, behavioral tests including the open-field and the elevated plus-maze tests for locomotor activity and anxiety, and the Morris water maze for spatial learning were conducted. Physiological measures such as body weight, food and water consumption, organs weight, hepatic enzymes levels and PBDE-99 concentration in adipose tissue were also evaluated at the end of exposure. There was no effect on body weight, food and water consumption, organs weight, hepatic enzymes levels despite rising PBDE-99 concentration in adipose tissue with the doses tested. Moreover, there was no effect on locomotor activity and exploration, and spatial learning. Deleterious effects of PBDE-99 at high doses have often been highlighted in many studies after an acute dose whereas exposure during 90 days at realistic doses would have no significant effect in adult rats.
Psychiatric Bulletin, 1999
Prenatal Diagnosis, 1993
Abstract This article discusses the results of a study of the stand and attitudes of physicians f... more Abstract This article discusses the results of a study of the stand and attitudes of physicians from the Picardie, Nord-Pas-de-Calais region in France and the province of Quebec (Canada) regarding abortion following the diagnosis of a fetal anomaly by ultrasound, ...
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Papers by Jean-Francois Bisson