Control activo global multicanal del ruido de baja frecuencia en recintos

9 pp.-- PACS nr.: 43.50.Ki.-- Comunicación presentada en los siguientes congresos: XXX Jornadas Nacionales de Acústica – TecniAcústica 1999. Encuentro Ibérico de Acústica (Ávila, 20-22 Octubre 1999).Publicado en número especial de la Revista de Acústica: Vol 30(1999).[EN] In this work, an Active Noise Control system has been implemented in a slightly damped room harmonically excited. We are interested in the reduction of the sound pressure level over the whole enclosure, global control, so we have to consider the modal overlapping in order to discriminate between diffuse and modal field. The sum of the square pressure levels at the discrete sensor positions has been reduced using the Filtered-X LMS algorithm. Important reductions can be obtained when the secondary sources are far away from the primary source, but the best results are achieved when the secondary sources are closed to the primary one.[ES] En este trabajo se ha realizado una verificación experimental de las posibilidades de las técnicas de Control Activo del Ruido (CAR) en recintos. Concretamente, en un recinto paralelepipédico de dimensiones 6.81 x 5.23 x 3.38 m, ligeramente amortiguado y excitado armónicamente. Debido a que la forma del recinto se adapta perfectamente a coordenadas cartesianas y trabajamos en un margen de bajas frecuencias, la ecuación de ondas es exactamente resoluble y podemos expresar la solución utilizando teoría de modos normales sin necesidad de recurrir a procedimientos numéricos más complicados. Para medir la respuesta global del recinto se utiliza la energía potencial acústica medida en un número discreto de sensores de error, minimizándose el cuadrado de la presión en esas posiciones mediante un sistema comercial que implementa el algoritmo FX-LMS.Las aplicaciones prácticas de las técnicas CAR en recintos van dirigidas esencialmente al control del ruido de baja frecuencia en las cabinas de los aviones y en el interior de los vehículos, para el control del booming del habitáculo. En estos problemas es imposible aplicar técnicas de control pasivo sin aumentar de forma considerable el peso, y por tanto, el consumo. En ambos casos existen numerosos trabajos realizados con éxito.Este trabajo ha sido posible gracias al soporte financiero de la Comisión Interministerial de Ciencia y Tecnología (Proyecto AMB97-1175-C03-01).Peer reviewe

Predicción del campo acústico en recintos con geometría irregular para un sistema de control activo del ruido

7 pp.-- PACS nr.: 43.50.Ki.-- Comunicación presentada en: XXXII Congreso Nacional de Acústica – TecniAcústica 2001 y Encuentro Ibérico de Acústica (Logroño, 17-19 Octubre 2001).Publicado en número especial de la Revista de Acústica: Vol 32(2001).[EN] The distribution of the sensors and actuators in an active noise control system imposes a limit in the maximum attenuation levels to be reached. In real applications, irregular shaped cavities are often involved, whose modal characteristics are fundamental to a better understanding of the sound mechanism and any active noise reduction to be taken. The most popular alternatives are numerical methods. In this work, an approach is presented for computing acoustic properties of cavities of arbitrary shape, approximating the cavity geometry by a set of rectangular subcavities. The adjacent ones are jointed together by means of vibrating membranes.[ES] La distribución espacial de los tranductores en un sistema de control activo del ruido impone un limite a los valores de atenuación máximos que pueden obtenerse. En la mayoría de los problemas que se presentan en la práctica aparecen geometrías irregulares, cuya respuesta acústica no puede predecirse utilizando métodos clásicos de separación de variables. Las alternativas más utilizadas en estos casos son los métodos numéricos. En este trabajo se utilizan un método que consiste en la discretizacion de la cavidad por subcavidades más pequeñas cuya geometría se conoce. Las cavidades adyacentes se acoplan a través de membranas vibrantes.Este trabajo ha sido posible gracias al soporte financiero de la Comisión Interministerial de Ciencia y Tecnología (Proyecto AMB99-1095-C02-01).Peer reviewe

Localización óptima de los transductores en un sistema de control activo en un recinto

7 pp.-- PACS nr.: 43.50.Kj.-- Comunicación presentada en los siguientes congresos: II Congreso Iberoamericano de Acústica. XXXI Congreso Nacional de Acústica – TecniAcústica 2000. II Jornadas Iberoamericanas de Ultrasonidos. II Congreso Ibérico de Acústica. EAA Symposium on Architectural Acoustics (Madrid, 16-20 Octubre 2000).Publicado también en número especial de la Revista de Acústica, Vol. XXXI, año 2000.[EN] The distribution of the sensors and actuators for an ANC system has been optimised in a small enclosure using the experimental measurement of the transfer functions. The objective function used is the sum of square sound pressure values at a discrete number of points inside. The attenuation for each different combination is calculated from the response of the secondary sources at these points and from the primary field at the same sensors. The sound field at a fixed height has been determined using a grid of microphones uniformly distributed.[ES] En este trabajo se han determinado las posiciones óptimas de los transductores en un sistema de Control Activo del Ruido en un recinto mediante la medida experimental de las funciones de transferencia. Los valores de la atenuación obtenidos se determinan mediante la suma de los cuadrados de la presión en un número discreto de puntos antes y después de la cancelación activa. El campo de presión sonora a una altura fija se determina mediante una malla de micrófonos distribuidos de forma uniforme.Este trabajo ha sido posible gracias al soporte financiero de la Comisión Interministerial de Ciencia y Tecnología (Proyecto AMB99-1095-C02-01).Peer reviewe

Fuga Dissociativa: Um Caso clínico

A dissociative fugue occurs when an individual with dissociative amnesia wanders away from their familiar surroundings, maintaining self‑care and apparently normal behavior to observers, lasting from hours to months in a row. New identities can be assumed and even organized travel can occur. While dissociative amnesia by itself may have a prevalence of around 7.2%, dissociative fugue is a rare entity, with unknown prevalence, and there are few reports in the literature. In this article, we describe a case of dissociative fugue in a 34‑year old woman that lasted eight months. Dissociative amnesia with fugue remains an interesting topic for further research since it can present a diagnostic challenge, there are currently no evidence‑based pharmacological treatments and prognosis varies greatly between patients.A fuga dissociativa ocorre quando um individuo com amnésia dissociativa viaja para fora do seu ambiente habitual, mantendo autocuidado e apresentando comportamento aparentemente normal. Este quadro pode durar horas a meses. Podem ser assumidas novas identidades e viagens organizadas podem acontecer. Apesar da prevalência da amnésia dissociativa ser estimada em cerca de 7,2%, a fuga dissociativa é uma entidade rara, de prevalência desconhecida e existindo poucos casos relatados na literatura. Neste artigo, descrevemos um caso de fuga dissociativa numa mulher de 34 anos, que durou oito meses. A amnésia dissociativa com fuga permanece um tópico interessante para investigação futura porque constitui um desafio diagnóstico, não existe tratamento farmacológico recomendado baseado na evidência e o prognóstico é altamente variável entre doentes

Host/Guest Simulation of Fluorescent Probes Adsorbed into Low-Density Polyethylene, 1. Excimer Formation of 1,3-Di(1-pyrenyl)propane

Molecular dynamics and Rotational Isomer State/Monte Carlo techniques with a Dreiding 1.01 Force Field are employed to study the excimer formation of isolated 1,3-di(1-pyrenyl)propane and the probe adsorbed into a low-density polyethylene (LDPE) matrix model. The probability of formation of each molecular conformer at several temperatures was calculated using these theoretical techniques. Conformational statistical analysis of the four torsion angles (ϕ₁, ϕ₂, θ₁, θ₂) of Py3MPy showed that the angles —C—Cᵃʳ— (ϕ₁, ϕ₂) present two states c ± = ±90°; and the angles —C—C— (θ₁, θ₂), the three trans states = 180°, g ± = ±60°. The correlation of θ₁–θ₂ torsion angles showed that the most probable pairs were g⁺g⁻ and g⁻g⁺ for the excimer-like specimens, although these angles are distorted because of interactions with the polymer matrix. The temperature dependence of the excimer-formation probability revealed that this process was thermodynamically controlled in the isolated case. When the probe was adsorbed into the LDPE matrix, the excimer formation process was reversed at T = 375 K. At T > 375 K, the behavior was similar to the isolated case but, at T < 375 K, excimer formation probability increased with temperature as found experimentally by steady-state fluorescence spectroscopy. This temperature was coincident with the onset of the LDPE melting process, determined experimentally by thermal analysis.The authors wish to thank Brite EuRam programme (BE97-4472) and CAM (07N/0002/1998) for support

Micromorphology and Relaxation Processes of Low Density Polyethylene Probed by Fluorescence Spectroscopys

Fluorescence spectra of molecular guests at several temperatures are useful technique to study several types of polymer properties. In particular, it has been often employed to study polymer relaxation processes either in static or in dynamic conditions. In this work some applications of the steady-state fluorescence spectroscopy of different guests in polyethylene and in particular reports the photophysical behavior of 1,3-di(1-pyrenyl)propane (1Py(3)1Py) sorbed in low density polyethylene are shown. This molecular probe differs of pyrene by its ability to form intramolecular excimer species and we discuss the temperature dependence of this formation. In this study we recorded simultaneously the fluorescence spectra and the differential scanning calorimetry (dsc) traces. The relative dependence of fluorescence intensities on temperature of the higher energy vibronic band at 367 nm, of the isolated choromophore emission and of the excimer emission were discussed and associated with the polyethylene polymer relaxation processes. The influence of the macroscopic stretching upon the polymer relaxation processes and the fluorescence emission was also investigated and compared with previous results.J. B. thanks Brite EuRam/EU (BE97-4472) and to CICYT (MAT2000-0391-P4-02) for financial support. T. D. Z. A. thanks FAPESP and CNPq (Brazil) for financial support and a fellowship. S. B. Y. thanks FAPESP (Brazil) for a fellowship. The authors thank Prof. Carol Collins for useful discussions

Photochemical sensing of semicrystalline morphology in polymers: Pyrene in Polyethylene

Pyrene was inserted into a low-density polyethylene matrix. Fluorescence spectra as a function of temperature and the differential scanning calorimetry (DSC) trace were recorded simultaneously. Along with the usual vibronic bands, a low-intensity band at 365 nm appears at higher energies with respect to the 0−0 transition in the pyrene fluorescence spectra. The fluorescence intensity of this small band increased with temperature, and an isoemissive point was observed to occur at 368 nm. This emission was interpreted as arising from pyrene molecules located in the outer rigid interfacial region of polymer crystallites. Its temperature-dependent fluorescence was interpreted in terms of electron−phonon coupling; two phonons which coincide with fundamental vibrations of polyethylene were necessary to fit experimental data. Coupling with a high-energy phonon was possible at low temperature, whereas, above the β relaxation temperature, phonon coupling occurs with a lower-energy phonon. The α relaxation was detected as a maximum in fluorescence intensity since above its characteristic temperature, nonradiative processes begin to operate.J. Baselga thanks CAM and CICYT (Projects No. 247/92 and MAT 93-0823} for financial support. T.D.Z.A. thanks FAPESP, FINEP, and CNPq (Brazil} for financia} support

Acompanhamento da criança, do jovem e familia com cardiopatia proveniente dos paises africanos de lingua oficial portuguesa durante o tratamento em Portugal

Mestrado, Enfermagem de Saúde Infantil e Pediatria, 2012, Escola Superior de Enfermagem de LisboaAs crianças, os jovens e famílias provenientes dos Países Africanos de Língua Oficial Portuguesa (PALOP), que chegam ao hospital de Santa Marta ao abrigo dos acordos de cooperação internacional no domínio da saúde para tratamento médico e/ou cirúrgico da patologia cardíaca, constituem um grupo de utentes com necessidades especiais e sujeitos a várias vulnerabilidades. Estas devem-se à sua situação de saúde, à proveniência de um contexto cultural distinto e às inúmeras dificuldades com que se deparam em Portugal - país acolhedor -, por os acordos de saúde se mostrarem desajustados, desadequados face aos tempos atuais e, muitas vezes, não serem cumpridos pelos países de origem. A divulgação dos direitos e deveres destes utentes entre os profissionais que deles cuidam nos mais variados contextos, e entre os próprios utentes, bem como o conhecimento de possíveis recursos, são factores que auxiliam a ultrapassar situações de doença e a promover cuidados de enfermagem culturalmente competentes. A necessidade de conhecer e garantir o acompanhamento de todo o processo, fundamentando a intervenção de enfermagem na teoria da diversidade e universalidade dos cuidados desenvolvida por Madeleine Leininger, no sentido de assegurar a eficácia do tratamento, prevenir situações de risco e promover a garantia de continuidade de cuidados, implicando toda a equipa de enfermagem e a criança, o jovem e a família nos cuidados conduziu à implementação deste projecto. A reflexão sobre a prática, a partilha de experiências em diferentes contextos de cuidados e a revisão de literatura foram etapas da metodologia utilizada para fundamentar e justificar a pertinência deste projecto. Este texto corresponde ao relatório de estágio e nele procura-se dar a conhecer e fundamentar a experiência significativa em cada um dos campos seleccionados com vista ao desenvolvimento do projecto Acompanhamento da Criança/do Jovem e Família com cardiopatia proveniente dos PALOP, durante o tratamento em Portugal

Repeated Exposure to Ketamine in Adolescent Rats Results in Persistent Anxiety in the Adulthood

Background. Adolescent development of the prefrontal cortex (PFC) is accompanied by important changes in glutamatergic, GABAergic and dopaminergic circuitries, susceptible to modulation by N-methyl-D-aspartate receptors (NMDAR) antagonists. Repeated ketamine was associated with social and memory deficits, but other relevant factors, such as anxiety, were not sufficiently addressed. The present study aimed to examine the behavioral and molecular consequences of repeated exposure to ketamine with a particular focus in anxiety. Methods. We treated male adolescent Wistar rats, starting postnatal day (PND) 35, with ketamine (30 mg/kg, i.p, 7 days). Behavioral evaluation was conducted in the adulthood (PND 60). The elevated plus maze (EPM) and open field tests were used to evaluate anxiety and locomotion, while sociability and novelty recognition were assessed through the novel object recognition (NOR) and the sociability and social novelty tests. At the end of the behavioral evaluation, brains were dissected and the prefrontal cortex used for biochemical evaluation. Results. Analysis of the elevated plus maze (EPM) data revealed a ketamine-induced anxiety-like profile, corroborated by the open field data. Ketaminetreated rats also failed to increase contact time with a conspecific in the social affiliation test and with an unknown rat in the novelty preference test. At the molecular level, frontal expression levels of tyrosine hydroxylase were found decreased. Conclusion. Altogether, these results show that repeated ketamine-exposure in the adolescent may result in long-term anxietyinfo:eu-repo/semantics/publishedVersio

Evaluation of 99mTc-Sestamibi as a potential tool to investigate PgP activity in inflammation

In the XXI Century’s Society the scientific investigation process has been rowing steadily, and the field of the pharmaceutical research is one of the most enthusiastic and relevant. Here, it is very important to correlate bserved functional alterations with possibly modified drug bio distribution patterns. Cancer, inflammation and infection are processes that induce many olecular intermediates like cytokines, chemokines and other chemical complexes that an alter the pharmacokinetics of many drugs. One cause of such changes is hought to be the modulator action of these complexes in the P-Glycoprotein activity, because they can act like inducers/inhibitors of MDR-1 expression. This protein results from the expression of MDR-1 gene, and acts as an ATP energy-dependent efflux pump, withtheir substrates including many drugs, like antiretrovirals, anticancers, anti-infectives, immunosuppressants, steroids or opioids. Because of the lack of methods to provide helpful information in he investigation of in vivo molecular changes in Pgp activity during fection/infl ammation processes, and its value in the explanation of the altered drug harmacokinetic, this paper want to evaluate the potential utility of 99m Tc-Sestamibi scintigraphy during this kind of health sciences investigation. Although the aim is indeed to create a technique to the in vivo study of Pgp activity, this preliminary Project only reaches the in vitro study phase, assumed as the first step in a n evaluation period for a new tool development. Materials and Methods: For that reason , we are performing in vitro studies of influx and efflux of 99m Tc - Sestamibi ( that is a substrate of Pgp) in hepatocytes cell line (HepG2). We are interested in clarify the cellular behavior of this radiopharmaceutical in Lipopolysaccharide(LPS) stimulated cells ( well known in vitro model of inflammation) to possibly approve this methodology. To validate the results, the Pgp expression will be finally evaluated using Western Blot technique. Results: Up to this moment , we still don’t have the final results, but we have already enough data to let us believe that LPS stimulation induce a downregulation of MDR - 1, and consequently Pgp, which could conduce to a prolonged retention of 99m Tc - Sestamibi in the inflamed cells . Conclusions: If and when this methodology demonstrate the promising results we expect, one will be able to con clude that Nuclear Medicine is an important tool to help evidence based research also on this specific field