75 research outputs found
NOUVELLE APPROCHE DE LA METHODE DES VOLUMES FINIS ‘MVF’ DEDIEE A LA RESOLUTION DES PROBLEMES ELECTROMAGNETIQUES 3D
Nous proposons dans le cadre de ce travail une nouvelle approche de la méthode des volumes finis dédié principalement à lamodélisation tridimensionnelle des phénomènes électromagnétiques au sein des dispositifs électrotechniques. Le maillageadopté est un maillage non-structuré qui requiert un mailleur indépendant, spécifique, parfaitement adapté à l’algorithmenumérique. Son rôle est de partitionner l’application étudiée en cellules élémentaires de forme aussi variée que des trianglesdans le cas bidimensionnel et tétraèdres voir prismatique dans le cas tridimensionnel. Cette approche est avantageuse comparéeaux approches présentées dans des travaux précédents par le faite quelle s’adapte parfaitement à la modélisationtridimensionnelle des problèmes électromagnétiques dans des dispositifs ayants des géométries complexe d’une part, d’autrepart, elle peut résoudre des problèmes électromagnétiques où les matériaux magnétiques sont utilisés dans la conception desdispositifs étudiés, contrairement à celles déjà présenté précédemment, où seulement on peut traiter les problèmes ayant desdispositifs conçut à partir des matériaux amagnétiques [1] voir diamagnétiques [2] comme par exemple les matériauxsupraconducteurs à haute température critique. L’ensemble des modèles mathématiques et numériques est implémenté dans uncode de calcul tridimensionnel sous environnement Matlab. La validité du travail présenté est atteinte par la comparaison desrésultats obtenus avec des résultats expérimentaux trouvés dans la littérature [3]
TRPV1 in Brain Is Involved in Acetaminophen-Induced Antinociception
Background: Acetaminophen, the major active metabolite of acetanilide in man, has become one of the most popular overthe- counter analgesic and antipyretic agents, consumed by millions of people daily. However, its mechanism of action is still a matter of debate. We have previously shown that acetaminophen is further metabolized to N-(4-hydroxyphenyl)-5Z,8Z,11Z,14Z-eicosatetraenamide (AM404) by fatty acid amide hydrolase (FAAH) in the rat and mouse brain and that this metabolite is a potent activator of transient receptor potential vanilloid 1 (TRPV1) in vitro. Pharmacological activation of TRPV1 in the midbrain periaqueductal gray elicits antinociception in rats. It is therefore possible that activation of TRPV1 in the brain contributes to the analgesic effect of acetaminophen. Methodology/Principal Findings: Here we show that the antinociceptive effect of acetaminophen at an oral dose lacking hypolocomotor activity is absent in FAAH and TRPV1 knockout mice in the formalin, tail immersion and von Frey tests. This dose of acetaminophen did not affect the global brain contents of prostaglandin E-2 (PGE(2)) and endocannabinoids. Intracerebroventricular injection of AM404 produced a TRPV1-mediated antinociceptive effect in the mouse formalin test. Pharmacological inhibition of TRPV1 in the brain by intracerebroventricular capsazepine injection abolished the antinociceptive effect of oral acetaminophen in the same test. Conclusions: This study shows that TRPV1 in brain is involved in the antinociceptive action of acetaminophen and provides a strategy for developing central nervous system active oral analgesics based on the coexpression of FAAH and TRPV1 in the brain
A Human TREK-1/HEK Cell Line: A Highly Efficient Screening Tool for Drug Development in Neurological Diseases
TREK-1 potassium channels are involved in a number of physiopathological processes such as neuroprotection, pain and depression. Molecules able to open or to block these channels can be clinically important. Having a cell model for screening such molecules is of particular interest. Here, we describe the development of the first available cell line that constituvely expresses the TREK-1 channel. The TREK-1 channel expressed by the h-TREK-1/HEK cell line has conserved all its modulation properties. It is opened by stretch, pH, polyunsaturated fatty acids and by the neuroprotective molecule, riluzole and it is blocked by spadin or fluoxetine. We also demonstrate that the h-TREK-1/HEK cell line is protected against ischemia by using the oxygen-glucose deprivation model
Antiretroviral-naive and -treated HIV-1 patients can harbour more resistant viruses in CSF than in plasma
Objectives The neurological disorders in HIV-1-infected patients remain prevalent. The HIV-1 resistance in plasma and CSF was compared in patients with neurological disorders in a multicentre study. Methods Blood and CSF samples were collected at time of neurological disorders for 244 patients. The viral loads were >50 copies/mL in both compartments and bulk genotypic tests were realized. Results On 244 patients, 89 and 155 were antiretroviral (ARV) naive and ARV treated, respectively. In ARV-naive patients, detection of mutations in CSF and not in plasma were reported for the reverse transcriptase (RT) gene in 2/89 patients (2.2%) and for the protease gene in 1/89 patients (1.1%). In ARV-treated patients, 19/152 (12.5%) patients had HIV-1 mutations only in the CSF for the RT gene and 30/151 (19.8%) for the protease gene. Two mutations appeared statistically more prevalent in the CSF than in plasma: M41L (P = 0.0455) and T215Y (P = 0.0455). Conclusions In most cases, resistance mutations were present and similar in both studied compartments. However, in 3.4% of ARV-naive and 8.8% of ARV-treated patients, the virus was more resistant in CSF than in plasma. These results support the need for genotypic resistance testing when lumbar puncture is performe
Thermal Instability of a Power-Law Fluid Flowing in a Horizontal Porous Layer with an Open Boundary: A Two-Dimensional Analysis
Natural Convection in a Horizontal Porous Cavity Filled With a Non-Newtonian Binary Fluid of Power-Law Type
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