Experimental study on the dynamics of gas-fluidized beds.

Gas-fluidized fine powders display three regimes of fluidization: solidlike, fluidlike, and bubbling. We investigate, from both macroscopic and local measurements, the transition between these regimes. We show that the transition between the solidlike and the fluidlike regimes takes place along an interval of gas velocities in which transient active regions alternate with transient solid networks.

[Takayasu's arteritis].

Background: Takayasu's arteritis is a rare vasculitis in the pediatric population that affects the aorta and its branches. There are few studies with an appropriate number of patients and follow-up.

Objective: To describe the clinical manifestations, laboratory alterations, radiological findings, and treatment in eight children and adolescents with Takayasu's arteritis.

Fluid flow induced by nonuniform ac electric fields in electrolytes on microelectrodes. III. Observation of streamlines and numerical simulation.

The application of a nonuniform ac electric field to an electrolyte using coplanar microelectrodes results in steady fluid flow. The flow has its origin in the interaction of the tangential component of the nonuniform field with the induced charge in the electrical double layer on the electrode surfaces. Termed ac electro-osmosis, the flow has been studied experimentally and theoretically using linear analysis.

Impact of community-wide police car deployment of automated external defibrillators on survival from out-of-hospital cardiac arrest.

Background: Disappointing survival rates from out-of-hospital cardiac arrests encourage strategies for faster defibrillation, such as use of automated external defibrillators (AEDs) by nonconventional responders.

Methods And Results: AEDs were provided to all Miami-Dade County, Florida, police. AED-equipped police (P-AED) and conventional emergency medical rescue (EMS) responders are simultaneously deployed to possible cardiac arrests.

Fine cohesive powders in rotating drums: Transition from rigid-plastic flow to gas-fluidized regime.

We investigate the dynamics of fine cohesive powders inside rotating drums. We show that these powders may be fluidized due to entrapment of ambient gas, and we determine the onset of fluidization. Experimental measurements on the bed expansion as a function of the rotation velocity have been performed.

Differences in the activation patterns between sustained and self-terminating episodes of human ventricular fibrillation.

Background: Experimental studies have suggested that R-R interval dynamics during ventricular fibrillation (VF) have organized features, but whether dynamic behavior of non-sustained VF differs from sustained VF is unknown.

Aim: The purpose of this study was to investigate whether the dynamics of R-R intervals during non-sustained VF differs from the dynamics during sustained VF.

Methods: A group of 67 patients undergoing routine implantable cardioverter defibrillator (ICD) testing was studied.

Impaired negative chronotropic response to adenosine in patients with inappropriate sinus tachycardia.

Introduction: Adenosine is an endogenous nucleoside that has an important role in the diagnosis and treatment of several cardiac arrhythmias. However, its effects on inappropriate sinus tachycardia (IST) are not well established.

Methods And Results: In this study, the response to intravenous adenosine (0.

Effects of carvedilol on heart rate dynamics in patients with congestive heart failure.

Background: Patients with congestive heart failure (CHF) have alterations in the traditional and nonlinear indices of heart rate (HR) dynamics, which have been associated with an increased risk of mortality. This study was designed to test the effects of carvedilol, a nonselective beta-blocker with alpha-1 blocking properties, on HR dynamics in patients with CHF.

Methods: We studied 15 patients with CHF secondary to ischemic or idiopathic cardiomyopathy who met the following inclusion criteria: NYHA functional class II-III, optimal conventional medical therapy, normal sinus rhythm, left ventricular ejection fraction (LVEF) of < 40%, and resting systolic blood pressure greater than 100 mmHg.

Looking for self-organized critical behavior in avalanches of slightly cohesive powders.

We report results from a statistical analysis of avalanches of cohesive powders in a slowly rotated drum. Interparticle adhesion, which diminishes the effect of inertia and whose magnitude strongly fluctuates in a local scale, makes avalanches in slightly cohesive powders eligible for displaying self-organized criticality. However, the results show that avalanche sizes, time interval between avalanches, and maximum stable angle do not follow a power-law distribution.

Aggregation and sedimentation in gas-fluidized beds of cohesive powders.

We present measurements on the settling velocity of gas-fluidized beds of fine cohesive powders. In the solidlike regime (solid volume fraction straight phi>straight phi(c)) particles are static, sustained by enduring contacts. The settling is hindered by interparticle contacts and is a very slow process.

Long-term follow-up of contralateral lobe in patients hemithyroidectomized for solitary follicular adenoma.

Objectives: Since there are no available conclusive studies on the long-term evolution of remnant thyroid tissue after hemithyroidectomy in patients who undergo surgery for solitary follicular adenomas, we searched for such cases in our records to elucidate this issue.

Design: Search criteria were as follows: (i) presence of a single palpable thyroid nodule with the remainder of the gland normal on palpation; (ii) clinically euthyroid status at the time of surgery; (iii) histological diagnosis of nodule as follicular adenoma; (iv) a hemithyroidectomy operation, sparing the contralateral lobe; (v) normal macroscopic aspect of the contralateral lobe at the time of surgery; and (vi) at least 4 years of postoperative follow-up.

Patients: Only 47 female cases were found to meet above criteria, with a mean age of 45.

Correlation between bulk stresses and interparticle contact forces in fine powders.

We present measurements of the tensile strength as a function of the consolidation stress for a set of fine cohesive powders (xerographic toners) of 12.7 microm particle size and with a range of concentration of submicron fumed silica as flow control additive. This additive is well known for its ability to control interparticle adhesion force.

Effect of vibration on the stability of a gas-fluidized bed of fine powder.

We have investigated the effect of vibrations on the stability of gas-fluidized beds of fine powders (particle size approximately 10 microm). The powder is uniformly fluidized by an adjustable gas flow that enables us to control the average solid volume fraction straight phi(0). The fluidized bed is then subjected to a vertical oscillatory motion of controlled amplitude and frequency.

c-Myb transcription is activated by protein kinase B (PKB) following interleukin 2 stimulation of Tcells and is required for PKB-mediated protection from apoptosis.

During T-cell activation, c-Myb is induced upon interleukin 2 (IL-2) stimulation and is required for correct proliferation of cells. In this paper, we provide evidence that IL-2-mediated induction of the c-myb gene occurs via the phosphoinositide 3-kinase (PI3K) signaling pathway, that protein kinase B (PKB) is the principal transducer of this signal, and that activation of the c-myb promoter can be abolished by deletion of conserved E2F and NF-kappaB binding sites. We show that Myb is required to protect activated peripheral T cells from bcl-2-independent apoptosis and that overexpression of oncogenic v-Myb is antiapoptotic.

[New pharmacological agents in heart failure].

Heart failure is a common and growing public health problem, with increasing incidence and prevalence over the last 2 decades. Despite improvements in its current management, heart failure is still associated with significant morbidity and mortality. This has motivated the search for newer therapeutic modalities, which are based on a better understanding on the pathophysiologic events that lead to heart failure.