Modeling the diffusion-erosion crossover dynamics in drug release.

A computational model is proposed to investigate drug delivery systems in which erosion and diffusion mechanisms are participating in the drug release process. Our approach allowed us to analytically estimate the crossover point between those mechanisms through the value of the parameter b (b_{c}=1) and the scaling behavior of parameter τ on the Weibull function, exp[-(t/τ)^{b}], used to adjust drug release data in pharmaceutical literature. Numerical investigations on the size dependence of the characteristic release time τ found it to satisfy either linear or quadratic scaling relations on either erosive or diffusive regimes.

Vertical stratification of insect abundance and species richness in an Amazonian tropical forest.

Tropical forests are among the most biodiverse biomes on the planet. Nevertheless, quantifying the abundance and species richness within megadiverse groups is a significant challenge. We designed a study to address this challenge by documenting the variability of the insect fauna across a vertical canopy gradient in a Central Amazonian tropical forest.

Association between Microvolt T-Wave Alternans and Malignant Ventricular Arrhythmias in Chagas Disease.

Background: Sudden cardiac death is the most frequent death mechanism in Chagas disease, responsible for 55% to 65% of the deaths of patients with chronic Chagas cardiomyopathy (CCC). The most often involved electrophysiological mechanisms are ventricular tachycardia and ventricular fibrillation. The implantable cardioverter defibrillator (ICD) has a beneficial role in preventing sudden death due to malignant ventricular arrhythmias, and, thus the correct identification of patients at risk is required.

Safety of early performance of the six-minute walk test following acute myocardial infarction: a cross-sectional study.

Background: The six-minute walk test (6MWT) is a simple, low cost, reliable, and valid method for evaluating the functional capacity of cardiac patients. However, its early use and safety following acute myocardial infarction (AMI) is recent and has been little investigated.

Objective: To evaluate and to compare the safety and the cardiac behavior of early performance of the 6MWT in patients following uncomplicated AMI up to 4 days or more than 4 days after the event.

Residual entropy and waterlike anomalies in the repulsive one dimensional lattice gas.

The thermodynamics and kinetics of the one dimensional lattice gas with repulsive interaction are investigated using transfer matrix technique and Monte Carlo simulations. This simple model is shown to exhibit waterlike anomalies in density, thermal expansion coefficient, and self-diffusion. An unified description for the thermodynamic anomalies in this model is achieved based on the ground state residual entropy which appears in the model due to mixing entropy in a ground state phase transition.

Cadaveric study of breast measurements during augmentation with implants.

Background: The goal of this study was to compare immediate changes in breast shape and nipple position using different implant shapes and volumes, with variable release of the pectoralis major muscle in fresh cadavers.

Methods: Seventeen fresh cadaveric breasts were analyzed. Six different augmentation procedures were performed, including pocket dissection in the submuscular and subglandular planes, and partial and full release of the pectoralis major muscle insertion.

Ventricular arrhythmias in Chagas disease.

Sudden death is one of the most characteristic phenomena of Chagas disease, and approximately one-third of infected patients develop life-threatening heart disease, including malignant ventricular arrhythmias. Fibrotic lesions secondary to chronic cardiomyopathy produce arrhythmogenic substrates that lead to the appearance and maintenance of ventricular arrhythmias. The objective of this study is to discuss the main clinical and epidemiological aspects of ventricular arrhythmias in Chagas disease, the specific workups and treatments for these abnormalities, and the breakthroughs needed to determine a more effective approach to these arrhythmias.

Prognostic score for acute coronary syndrome in a private terciary hospital.

Background: Available predictive models for acute coronary syndromes (ACS) have limitations as they have been elaborated some years ago or limitations with applicability.

Objectives: To develop scores for predicting adverse events in 30 days and 6 months in ST-segment elevation and non-ST-segment elevation ACS patients admitted to private tertiary hospital.

Methods: Prospective cohort of ACS patients admitted between August, 2009 and June, 2012.

Laparoscopic cholecystectomy with suprapubic approach.

Background: The laparoscopic cholecystectomies performed through single site surgery, despite undoubted aesthetic results, are costly and technically difficult to be performed. The suprapubic approach presents as a simpler and cheaper alternative with good aesthetic results.

Aim: To report the experience of Garavelo Hospital on laparoscopic cholecystectomy with suprapubic approach.

Efficacy and safety of implantable cardioverter-defibrillators in patients with Chagas disease.

Aims: Implantable cardioverter-defibrillators (ICDs) are now a first-line option for prevention of sudden death in Chagas disease (ChD). However, efficacy and safety of ICD treatment in ChD remains controversial. The aim of our study was to compare clinical outcome after ICD implantation in ChD and non-ChD patients.

Thermodynamic and dynamic anomalies in a one-dimensional lattice model of liquid water.

We investigate the occurrence of waterlike thermodynamic and dynamic anomalous behavior in a one dimensional lattice gas model. The system thermodynamics is obtained using the transfer matrix technique and anomalies on density and thermodynamic response functions are found. When the hydrogen bond (molecules separated by holes) is more attractive than the van der Waals interaction (molecules in contact) a transition between two fluid structures is found at null temperature and high pressure.

Solution of an associating lattice-gas model with density anomaly on a Husimi lattice.

We study a model of a lattice gas with orientational degrees of freedom which resemble the formation of hydrogen bonds between the molecules. In this model, which is the simplified version of the Henriques-Barbosa model, no distinction is made between donors and acceptors in the bonding arms. We solve the model in the grand-canonical ensemble on a Husimi lattice built with hexagonal plaquettes with a central site.

Molecular correlations and solvation in simple fluids.

We study the molecular correlations in a lattice model of a solution of a low-solubility solute, with emphasis on how the thermodynamics is reflected in the correlation functions. The model is treated in the Bethe-Guggenheim approximation, which is exact on a Bethe lattice (Cayley tree). The solution properties are obtained in the limit of infinite dilution of the solute.

Decentralized sensor fusion for Ubiquitous Networking Robotics in Urban Areas.

In this article we explain the architecture for the environment and sensors that has been built for the European project URUS (Ubiquitous Networking Robotics in Urban Sites), a project whose objective is to develop an adaptable network robot architecture for cooperation between network robots and human beings and/or the environment in urban areas. The project goal is to deploy a team of robots in an urban area to give a set of services to a user community. This paper addresses the sensor architecture devised for URUS and the type of robots and sensors used, including environment sensors and sensors onboard the robots.

Stable angina and ST-segment depression: diagnostic value in patients undergoing coronary angiography.

Background: Clinical history and exercise testing (ET) are the main methods used to screen for coronary artery disease (CAD). Correct interpretation of such data is essential in determining diagnostic and treatment strategies.

Objective: To assess the diagnostic value of stable angina (SA) and ET in patients with suspected CAD undergoing coronary angiography and to compare results between the sexes.

Standard Deviation of normal interbeat intervals as a risk marker in patients with left ventricular systolic dysfunction: a meta-analysis.

Our aim was to evaluate the Standard Deviation of Normal-Normal (SDNN) interbeat interval as a risk marker in left ventricular systolic dysfunction (LVSD) patients through a meta-analysis. We searched PubMed for studies that evaluated SDNN as a predictor of all-cause-death, cardiac death, transplantation, and progressive clinical deterioration using a search strategy validated for MEDLINE. Mean values and SD for SDNN in sixteen studies included were 115+/-48 ms in survivors versus 87+/-40 ms in non-survivors, resulting in a statistically significant standardized mean difference (0.

Frustration and anomalous behavior in the Bell-Lavis model of liquid water.

We have reconsidered the Bell-Lavis model of liquid water and investigated its relation to its isotropic version, the antiferromagnetic Blume-Emery-Griffiths model on the triangular lattice. Our study was carried out by means of an exact solution on the sequential Husimi cactus. We show that the ground states of both models share the same topology and that fluid phases (gas and low- and high-density liquids) can be mapped onto magnetic phases (paramagnetic, antiferromagnetic, and dense paramagnetic, respectively).

Alternative hydrogen bond implementations produce opposite effects on collapse cooperativity of lattice homopolypeptide models.

We use complete enumeration of self-avoiding chains of up to N=26 monomers in two-dimensional lattices to investigate the effect of alternative implementations of backbone hydrogen bonds on the cooperativity of homopolypeptide collapse. Following a recent study on protein folding models, we use the square lattice with z=3 local conformations per monomer and lattice extensions containing diagonal steps which result in z=5 or z=7 and assume that only a subset of zh View Article and Find Full Text PDF

Treatment of massive pulmonary embolism by percutaneous fragmentation of the thrombus.

Objectives: To evaluate the safety and efficacy of percutaneous thrombus fragmentation (PTF) for massive pulmonary embolism (PE) in patients with contraindications to the administration of thrombolytics.

Methods: Between July 1999 and August 2005, 10 patients (7 males, 3 females, age 57+/-18 years) with massive PE and contraindications to the administration of thrombolytics underwent PTF. A transthoracic doppler echocardiogram was used to evaluate arterial oxygen saturation (Sat O2), the Walsh index (WI), mean pulmonary artery pressure (PAP), mean systemic blood pressure (SBP) and right ventricular function (RVF) before and after the procedure.