Search results for "electric [charge]"
showing 10 items of 729 documents
The role of the renin-angiotensin system in atrial fibrillation and the therapeutic effects of ACE-Is and ARBS
2008
Atrial fibrillation (AF) is the most common rhythm disturbance in medical practice and represents a very expensive health problem. AF can be managed with the prevention of thromboembolism and either a rate control of rhythm strategy. As both strategies have important limitations, probably a preventative strategy in patients at risk of developing arrhythmia can be a more attractive option. The renin-angiotensin system (RAS) seems to be involved in the genesis of arrhythmia by the following two mechanisms: 1. the induction of atrial fibrosis and structural remodelling by mitogen-activated protein kinase (MAPK) expression and reduction of collagenase activity; 2. the induction of electrical re…
Pharmacological Therapy in Children with Atrial Fibrillation and Atrial Flutter
2008
Heart rhythm disorders in children are not different, on electrocardiographic trace, from heart rhythm disorders in adults with the exception of incidence which is different according to the age. Paticularly, atrial flutter (FlA) and fibrillation (FA) are very uncommon arrhythmias in the general pediatric population. Generally atrial fibrillation and atrial flutter, in our experience, is a temporary heart rhythm disturbance connected to specifical and resovable reasons with the exception of Fontains surgical correction of congenital heart diseases or cardiopathies with dilatation of both atria. Presenting symptoms, symptom history (e.g., frequency, duration, and severity), risk assessment, …
Focus on right ventricular outflow tract septal pacing
2013
SummaryExperimental and clinical studies have shown that right ventricular apical pacing may result in long-term deleterious effects on account of its negative impact on left ventricular remodeling through desynchronization. This risk appears more pronounced in patients with even moderate left ventricular dysfunction and generally occurs after at least 1 year of pacing. As right ventricular apical pacing may be associated with the development of organic mitral insufficiency, other sites that allow for more physiological stimulation, such as right ventricular outflow tract septal pacing, have been developed, with good feasibility and reproducibility. However, the prospective randomized studi…
Secretory effect of azodisalicylate (azodisal sodium) on the short circuited mucosa of the rat ileum in vitro.
1988
Azodisalicylate (ADS) is one of the newly developed substitutes of sulphasalazine consisting of two molecules of 5-amino-salicylic acid. Azodisalicylate caused diarrhoea in some patients, apparently caused by an antiabsorptive secretagogue action of this compound. The mechanism of this was studied in the short circuited isolated mucosa of the rat ileum. Mucosal addition of ADS increased the potential difference (PD) and short circuit current (Isc) at a concentration of 1.3.10(-4) mol/l (4 mg/dl) with maximal effects at 1.3.10(-3) mol/l (40 mg/dl). Epithelial resistance was only slightly decreased at the higher concentrations of 40 and 100 mg/dl. Serosal ADS had no effect on electrical param…
Prospective appraisal of the prevalence of primary aldosteronism in hypertensive patients presenting with atrial flutter or fibrillation (PAPPHY Stud…
2013
Primary aldosteronism (PA) is the most common endocrine form of hypertension and may carry an increased risk of atrial flutter or fibrillation (AFF). The primary goal of this multicentre cohort study is thus to prospectively establish the prevalence of PA in consecutive hypertensive patients referred for lone (non-valvular), paroxysmal or permanent AFF. Secondary objectives are to determine: (1) the predictors of AFF in patients with PA; (2) the rate of AFF recurrence at follow-up after specific treatment in the patients with PA; (3) the effect of AFF that can increase atrial natriuretic peptide via the atrial stretch and thereby blunt aldosterone secretion, on the aldosterone-to-renin rati…
Peltier effect-based temperature challenge: an improved method for diagnosing cold urticaria.
2004
Détection des ruptures de fibres et du délaminage dans les composites verre/époxy et carbone/époxy à l'aide de structures propagatives dans la gamme …
2009
National audience; On présente dans cet article la détection de ruptures de fibre et du délaminage dans les composites unidirectionnels verre/époxy et carbone/époxy en utilisant des structures propagatives électromagnétiques dans la gamme des micro-ondes.
Dielectric properties of myoglobin at 10 GHz by microwave cavity perturbation measurements
2010
We report on the temperature dependence, at microwave (mw) frequency, of the imaginary part of the dielectric constant (En) in myoglobin powder samples with different hydration levels (h). The measurements have been performed by the cavity perturbation technique, in the range of temperature 80-345 K. The sample is located inside a glass capillary along the axis of a cylindrical copper cavity, resonating in the TE011 mode at 9.6 GHz, where the mw electric field has a node. By measuring the variation of the quality factor of the resonant cavity, one can extract the imaginary part of the dielectric constant. At temperatures higher than 230 K we observe an evident increase of the dielectric los…
Tetragonal tungsten bronzes Nb8−xW9+xO47−δ: optimization strategies and transport properties of a new n-type thermoelectric oxide
2015
Engineering of nanoscaled structures may help controlling the electrical and thermal transport in solids, in particular for thermoelectric applications that require the combination of low thermal conductivity and low electrical resistivity. The tetragonal tungsten bronzes Nb8−xW9+xO47 (TTB) allow a continuous variation of the charge carrier concentration while fulfilling at the same time the concept of a “phonon-glass electron-crystal” through a layered nanostructure defined by intrinsic crystallographic shear planes. The thermoelectric properties of the tetragonal tungsten bronzes Nb8−xW9+xO47−δ (0 < x < 2) were studied in the temperature range from 373 to 973 K. Structural defects and the…
Technical and economical comparison between NdFeB and hard ferrites linear electrical generators from sea waves
2015
In this paper the authors perform a technical-economic comparison of two different Tubular Permanent Magnet Linear Machines for sea waves generation by using finite elements analysis. The first configuration includes ferrite rings while the second configuration includes neodymium-iron-boron rings. In order to compare the two types in economic and technical terms, a detailed analysis of the main figures of merit of the two configurations has been carried out. In particular, significant data such as flux distribution, rated voltage and current, axial force, electric power, realization cost and maintenance cost have been compared.