Visual Evoked Potentials Change as Heart Rate and Carotid Pressure Change

The relationship between cardiovascular activity and the brain was explored by recording visual evoked potentials from the occipital regions of the scalp during systolic and diastolic pressure (Experiment I) and during fast and slow heartbeats at systolic and diastolic pressure (Experiment II). Visual evoked potentials changed significantly as heart rate and carotid pressure fluctuated normally, and these changes were markedly different in the right and left cerebral hemispheres. Evoked potentials recorded from the right hemisphere during various cardiac events differed significantly, whereas those recorded from the left did not. In both experiments, differences in the right hemisphere were due primarily to the P1 component, which was larger at diastolic than at systolic pressure. The present findings are consistent with formulations from behavioral studies suggesting that baroreceptor activity can influence sensory intake, and suggest that hemispheric specialization may play an important role in the relationship between cardiac events, the brain and behavior.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73146/1/j.1469-8986.1982.tb02579.x.pd

Therapeutic efficacy of TBC3711 in monocrotaline-induced pulmonary hypertension

Background: Endothelin-1 signalling plays an important role in pathogenesis of pulmonary hypertension. Although different endothelin-A receptor antagonists are developed, a novel therapeutic option to cure the disease is still needed. This study aims to investigate the therapeutic efficacy of the selective endothelin-A receptor antagonist TBC3711 in monocrotaline-induced pulmonary hypertension in rats. Methods: Monocrotaline-injected male Sprague-Dawley rats were randomized and treated orally from day 21 to 35 either with TBC3711 (Dose: 30 mg/kg body weight/day) or placebo. Echocardiographic measurements of different hemodynamic and right-heart hypertrophy parameters were performed. After day 35, rats were sacrificed for invasive hemodynamic and right-heart hypertrophy measurements. Additionally, histologic assessment of pulmonary vascular and right-heart remodelling was performed. Results: The novel endothelin-A receptor antagonist TBC3711 significantly attenuated monocrotaline-induced pulmonary hypertension, as evident from improved hemodynamics and right-heart hypertrophy in comparison with placebo group. In addition, muscularization and medial wall thickness of distal pulmonary vessels were ameliorated. The histologic evaluation of the right ventricle showed a significant reduction in fibrosis and cardiomyocyte size, suggesting an improvement in right-heart remodelling. Conclusion: The results of this study suggest that the selective endothelin-A receptor antagonist TBC3711 demonstrates therapeutic benefit in rats with established pulmonary hypertension, thus representing a useful therapeutic approach for treatment of pulmonary hypertension

Une classification géotechnique des craies du nord utilisée pour l’étude de stabilité des carrières souterraines

Dans le cadre de l'étude de stabilité des carrières souterraines du Nord de la France, le CERCHAR a effectué plus de 750 essais de résistance à la compression simple, sur des échantillons de craie en provenance de 25 sites.Le traitement statistique de cette information, par les techniques d'analyse des données usuelles, a mis en évidence des corrélations entre paramètres physiques et mécaniques.Lors d'études sommaires de stabilité, ces liaisons permettent d'estimer la résistance à la compression simple avec une précision suffisante pour être opérationnelle

Détermination d'un coefficient de sécurité dans les exploitations par chambres et petits piliers abandonnés

La notion de coefficient de sécurité statique utilisée dans le cadre d'étude de stabilité des exploitations par chambres et piliers abandonnés est abordée d'un point de vue statistique.Les caractéristiques mécaniques des matériaux et les sollicitations exercées sont considérées comme des variables aléatoires dont on définit les lois de distribution expérimentalement puis théoriquement. Cette démarche permet d'évaluer la probabilité du risque de ruine.La méthode proposée est appliquée au cas des carrières de Lezennes à plusieurs échelles où l'on confronte les résultats obtenus à partir de différents modèles de comportement, en utilisant les résultats d’essais de laboratoire et de mesures in situ

Improved Functionality and Control in the Isomerization of a Calix[4]Arene-Capped Azobenzene

An improved azobenzene core capped by two calix[4]arene units isomerizes readily between trans and cis configurations via photochemical and/or thermal means. In addition, the presence of acid (particularly HCl) increases the rate of thermal cis→trans conversion. These enhancements to the functional response, control, and understanding of calixarene-capped azobenzene isomerization are important for future application in the dynamic encapsulation of small chemical species. © 2011 Elsevier Ltd. All rights reserved