Current practices in the use of sildenafil for pulmonary arterial hypertension in Brazilian hospitals

<p>Abstract</p> <p>Background</p> <p>Sildenafil is a cyclic guanosine monophosphate-specific phosphodiesterase-5 inhibitor used for treating pulmonary hypertension. Although the use of sildenafil in patients under 18 years old is off-label, this inhibitor has been widely prescribed for children treatment at hospitals in Brazil. In this work we evaluated the current practices in using sildenafil in the three main reference hospitals of Rio de Janeiro to design a clinical trial. Then we analyzed the content of sildenafil in powder paper preparations used in these institutions.</p> <p>Methods and Results</p> <p>We assessed the data about the use of sildenafil in three reference hospitals including Instituto Nacional de Cardiologia – INC, Instituto Estadual de Cardiologia Aloysio de Castro – IECAC and Hospital Pro-Cardíaco – HPC. The pharmacy records were analyzed from April 1st, 2008 to April 30th, 2008 and interviews with the pharmacists were also performed. Our results showed that INC used the greatest amount of sildenafil in: treatment of pulmonary arterial hypertension (PAH), management of transient PAH during surgery, preparation for cardiac transplantation and haemodynamic studies during cardiac catheterization. Meanwhile IECAC and HPC used sildenafil only for treating PAH in few patients during the period evaluated. In INC and IECAC, sildenafil was available in tablets, and powder papers prepared by two private pharmacies and one public hospital pharmacy. In contrast all patients of HPC received sildenafil in tablets with no external manipulation. Our quantification analysis results using reverse-phase high performance liquid chromatography method showed that powder papers prepared by the private pharmacies from the sildenafil tablets presented only 58.5 to 89.3% of the declared concentration in contrast to samples from the public hospital pharmacy (104.4 to 105.3%).</p> <p>Conclusion</p> <p>Few patients received the prescribed sildenafil dose at the reference hospitals evaluated in Rio de Janeiro, which may importantly compromise this inhibitor effect in the current treatment. This study reinforced the need of checking the practices of preparing and administering sildenafil continually.</p

Towards Certified Model Checking for PLTL using One-pass Tableaux

The standard model checking setup analyses whether the given system specification satisfies a dedicated temporal property of the system, providing a positive answer here or a counter-example. At the same time, it is often useful to have an explicit proof that certifies the satisfiability. This is exactly what the {\it certified model checking (CMC)} has been introduced for. The paper argues that one-pass (context-based) tableau for PLTL can be efficiently used in the CMC setting, emphasising the following two advantages of this technique. First, the use of the context in which the eventualities occur, forces them to fulfil as soon as possible. Second, a dual to the tableau sequent calculus can be used to formalise the certificates. The combination of the one-pass tableau and the dual sequent calculus enables us to provide not only counter-examples for unsatisfied properties, but also proofs for satisfied properties that can be checked in a proof assistant. In addition, the construction of the tableau is enriched by an embedded solver, to which we dedicate those (propositional) computational tasks that are costly for the tableaux rules applied solely. The combination of the above techniques is particularly helpful to reason about large (system) specifications

Triply Differential Ionization of Ar by 500 EV Positron and Electron Impact

Coincidences between recoil ions-ejected electrons and recoil ions-scattered projectiles have been used to study the kinematics of electron and positron impact ionization. Triply Differential (TDCS) data for 500 eV positron and electron impact on Ar are presented here as function of scattering angle for a given range of energy losses. Binary and recoil interactions can be distinguished allowing us to determine the relative intensity between those interactions. Preliminary integration of the data indicate an enhancement of the binary region for positron interaction while for electron impact the intensity of the recoil and binary interactions is comparable

Doubly Differential Single and Multiple Ionization of Krypton by Electron Impact

Differential measurements for single and multiple ionization of Kr by 240 and 500 eV electron impact are presented. Using a pulsed extraction field, Kr+, Kr2+, and Kr3+ ions were measured in coincidence with scattered electrons for energy losses up to 120 eV and scattering angles between 16° and 90°. Scaling properties of the doubly differential cross sections (DDCS) are investigated as a function of energy loss, scattering angle, and momentum transfer. It is shown that scaling the DDCS as outlined by Kim and Inokuti and plotting them versus a parameter consisting of the momentum transfer divided by the square root of the impact energy times 1−cos(theta), where theta is the scattering angle, yielded similar curves, but with different magnitudes, for single and multiple ionization. Normalizing these curves together produced two universal curves, one appropriate for single and multiple electron emission at larger scattering angles (theta\u3e=30°) and one appropriate for small scattering angles (theta\u3c30°)

Differential Electron Emission for Single and Multiple Ionization of Argon by 500 EV Positrons

Triply differential electron emission cross sections are measured for single ionization of argon by 500 eV positrons. Data are presented for coincidences between projectiles scattered into angles of 3° and electrons with emission energies less than 10 eV that are observed between 45 and 135° along the beam direction. For interpretation, these are compared to cosine squared representations of the binary and recoil lobes which are convoluted over experimental parameters. Singly differential electron emission data for double and triple ionization by positrons are also presented

Un instrumento de apoyo al emprendedurismo en Argentina: el facilitador de flujos de proyectos

Trabajo presentado al XIII Seminario Latino-Iberoamericano de Gestión Tecnológica: "Innovación para el desarrollo sostenible" celebrado en Cartagena de Indias (Colombia) del 25 al 27 de Noviembre 2009.El presente trabajo tiene como objetivo caracterizar a un nuevo actor que brinde apoyo a emprendedores con propuestas de generación de empresas de base tecnológicas (EBTs) surgidas desde las instituciones de Ciencia y Tecnología en Argentina. Para ello, se realizaron entrevistas a actores calificados provenientes de los distintos entornos del sistema argentino de innovación y de otros países iberoamericanos así como un taller con representantes de organismos de Vinculación Tecnológica de universidades argentinas. Entre los entrevistados se incluyeron especialistas provenientes de oficinas de vinculación de universidades y centros de investigación, incubadoras de empresas, bancos, fondos de inversión de riesgo, consultores privados, y creadores de EBTs. Para sistematizar las entrevistas se estableció un cuestionario con un conjunto de preguntas, algunas cerradas y otras abiertas. Como resultados se presentan los principales condicionantes identificados que frenan el surgimiento de EBTs académicas, una breve caracterización de servicios y/o capacidades disponibles para superarlos en los organismos actuales y las características básicas propuestas para el nuevo actor. Finalmente se incluyen conclusiones sobre las posibilidades de actuación del nuevo actor, su conformación y condicionantes sobre los que podrá actuar con éxito y los que no, así como su pertenencia y/o su relación con los actuales actores del sistema de innovación.Peer reviewe

A novel mutation in SACS gene in a family from southern Italy

A form of autosomal recessive spastic ataxia (ARSACS) has been described in the Charlevoix and Saguenay regions of Quebec. So far a frameshift and a nonsense mutation have been identified in the SACS gene. The authors report a new mutation (1859insC), leading to a frameshift with a premature termination of the gene product sacsin, in two sisters from consanguineous parents. The phenotype is similar to previously described patients with ARSACS

Definition of tailor made cutting tools for machining of complex surfaces based on final surface shape

In this work a design methodology to define the best geometry of cutting tool for complex surfaces is defined, being based on the final part surface geometry. The manufacture of components with tailor made shaped tools, based on algorithm calculation and adapted to the geometry of the final piece surface, reduces manufacturing time and maintains piece quality in comparison with traditional cutting tools. Cutting tools are usually cylindrical (end mills) or ball-end mills. With mathematical algorithms can be defined diamond & CBN electroplated form tools, multi-tooth endmills, abrasive grinding tools and so on. The approach here presented can enable the production of tools for manufacturing process such as Super Abrasive Machining (SAM) and Flank milling strategies. Comparison between standard tools and traditional machining processes versus custom-shaped tools was studied in terms of process time. Final applications are numerous, such as, integral blade rotors, spiral bevel gears, blisks and impellers, complex screws, and others

Tidal stirring and the origin of dwarf spheroidals in the Local Group

N-Body/SPH simulations are used to study the evolution of dwarf irregular galaxies (dIrrs) entering the dark matter halo of the Milky Way or M31 on plunging orbits. We propose a new dynamical mechanism driving the evolution of gas rich, rotationally supported dIrrs, mostly found at the outskirts of the Local Group (LG), into gas free, pressure supported dwarf spheroidals (dSphs) or dwarf ellipticals (dEs), observed to cluster around the two giant spirals. The initial model galaxies are exponential disks embedded in massive dark matter halos and reproduce nearby dIrrs. Repeated tidal shocks at the pericenter of their orbit partially strip their halo and disk and trigger dynamical instabilities that dramatically reshape their stellar component. After only 2-3 orbits low surface brightness (LSB) dIrrs are transformed into dSphs, while high surface brightness (HSB) dIrrs evolve into dEs. This evolutionary mechanism naturally leads to the morphology-density relation observed for LG dwarfs. Dwarfs surrounded by very dense dark matter halos, like the archetypical dIrr GR8, are turned into Draco or Ursa Minor, the faintest and most dark matter dominated among LG dSphs. If disks include a gaseous component, this is both tidally stripped and consumed in periodic bursts of star formation. The resulting star formation histories are in good qualitative agreement with those derived using HST color-magnitude diagrams for local dSphs.Comment: 5 pages, 5 figures, to appear on ApJL. Simulation images and movies can be found at the Local Group web page at http://pcblu.uni.mi.astro.it/~lucio/LG/LG.htm

Experimental Determination of Momentum-Resolved Electron-Phonon Coupling

We provide a novel experimental method to quantitatively estimate the electron-phonon coupling and its momentum dependence from resonant inelastic x-ray scattering (RIXS) spectra based on the detuning of the incident photon energy away from an absorption resonance. We apply it to the cuprate parent compound NdBa$_2$Cu$_3$O$_6$ and find that the electronic coupling to the oxygen half-breathing phonon mode is strongest at the Brillouin zone boundary, where it amounts to $\sim 0.17$ eV, in agreement with previous studies. In principle, this method is applicable to any absorption resonance suitable for RIXS measurements and will help to define the contribution of lattice vibrations to the peculiar properties of quantum materials.Comment: 6 pages, 3 figure