377 research outputs found

    HUMAN-CENTERED DESIGN OF THE HUMAN-SYSTEM INTERFACES OF MEDICAL EQUIPMENT: THYROID UPTAKE SYSTEM

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    Technology plays an important role in modern medical centers, making healthcare increasingly complex, relying on complex technical equipment. This technical complexity is particularly noticeable in the nuclear medicine. Poorly design human–system interfaces can increase the risks for human error. The human-centered approach emphasizes the development of the equipment with a deep understanding of the users activities, current work practices, needs and abilities of the users. An important concept of human-centered design is that the ease-of-use of the equipment can be ensured only if users are actively incorporated in all phases of the life cycle of design process. Representative groups of users are exposed to the equipment at various stages in development, in a variety of testing, evaluation and interviewing situations. The users feedback obtained is then used to refine the design, with the result serving as input to the next interaction of design process. The limits of the approach are that the users cannot address any particular future needs without prior experience or knowledge about the equipment operation. The aim of this paper is to present a methodological framework that contributes to the design of the human-system interfaces, through an approach related to the users and their activities. A case study is described in which the methodological framework is being applied in development of new human-system interfaces of the thyroid uptake system

    Heteropterys Tomentosa (a. Juss.) Infusion Counteracts Cyclosporin A Side Effects On The Ventral Prostate.

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    Cyclosporin A (CsA) is an immunosuppressive drug widely used in treatment of auto-immune diseases or after organ transplants. However, several side effects are commonly associated with CsA long term intake, some regarding to loss of reproductive organ function due to oxidative damage. Considering that phytotherapy is an important tool often used against oxidative stress, we would like to describe the beneficial effects of Heteropterys tomentosa intake to minimize the damage caused by CsA to the ventral prostate tissue of Wistar rats under laboratorial conditions. Thirty adult Wistar rats (Rattus norvegicus albinus) were divided into: control group (water); CsA group (Cyclosporin A); Ht group (H. tomentosa infusion) and CsA + Ht group (CsA and H. tomentosa infusion). Plasmic levels of hepatotoxicity markers, triglycerides, cholesterol and glucose were quantified. The ventral prostate tissue was analyzed under light microscopy, using stereological, morphometrical and immunohistochemical techniques. H. tomentosa did not cause any alterations either of the plasmic parameters or of the ventral prostate structure. CsA caused alterations of GOT, total and indirect bilirubin, cholesterol, triglycerides and glucose levels in the plasma; CsA-treated rats showed alterations of the ventral prostate tissue. There were no alterations regarding the plasma levels of GOT, triglycerides and glucose of CsA + Ht animals. The same group also showed normalization of most of the parameters analyzed on the ventral prostate tissue when compared to the CsA group. The treatments did not alter the pattern of AR expression or the apoptotic index of the ventral prostate epithelium. The results suggest a protective action of the H. tomentosa infusion against the side effects of CsA on the ventral prostate tissue, which could also be observed with plasmic biochemical parameters.133

    Capacitive impedance measurement : dual-frequency approach.

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    The most widely used technique for measuring capacitive impedances (or complex electrical permittivity) is to apply a frequency signal to the sensor and measure the amplitude and phase of the output signal. The technique, although efficient, involves high-speed circuits for phase measurement, especially when the medium under test has high conductivity. This paper presents a sensor to measure complex electrical permittivity based on an alternative approach to amplitude and phase measurement: The application of two distinct frequencies using a current-to-voltage converter circuit based in a transimpedance amplifier, and an 8-bit microcontroller. Since there is no need for phase measurement and the applied frequency is lower compared to the standard method, the circuit presents less complexity and cost than the traditional technique. The main advance presented in this work is the use of mathematical modeling of the frequency response of the circuit to make it possible for measuring the dielectric constant using a lower frequency than the higher cut-off frequency of the system, even when the medium under test has high conductivity (tested up to 1220 ?S/cm). The proposed system caused a maximum error of 0.6% for the measurement of electrical conductivity and 2% for the relative dielectric constant, considering measurement ranges from 0 to 1220 ?S/cm and from 1 to 80, respectively

    Fatores que determinam a estrutura e distribuição das comunidades de invertebrados bentônicos em uma bacia hidrográfica tropical

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    We used the das Velhas River basin in southeastern Brazil as a study unit to evaluate the role of various physical and chemical variables and the state of conservation in determining the structure and distribution of benthic macroinvertebrate communities. The habitats were characterized through the use of a rapid evaluation protocol, the examination of the granulometric composition of the sediments, and the precipitation in the sub-basins of the segments studied. The taxonomic structure was determined, Shannon-Wiener and Simpson diversity indexes, taxonomic richness, % EPT and % Chironomidae for the benthic assemblages. The results corroborated the importance of habitats in spatial structuring, the importance of the hydrological regime in temporal structuring, and the state of conservation as the main structuring agents of benthic macroinvertebrate assemblages. Key words: biological metrics, bioindicators, protected areas, environmental impact.Foi utilizada a bacia hidrográfica do Rio das Velhas, sudeste do Brasil, como unidade de estudo para avaliar o papel das variáveis físicas e químicas além do estado de conservação na determinação da estrutura e distribuição das comunidades de macroinvertebrados bentônicos. A caracterização dos habitats foi realizada através da utilização de um protocolo de avaliação rápida, da determinação da composição de granulométrica dos sedimentos e da precipitação nas sub-bacias hidrográficas dos segmentos estudados. Foi determinada a estrutura taxonômica das comunidades bentônicas através dos índices de diversidade de Shannon-Wiener e Simpson, além da riqueza taxonômica, % EPT e % Chironomidae. Os resultados encontrados corroboraram a importância dos habitats na estruturação espacial, do regime hidrológico na estruturação temporal e o estado de conservação como o principal agente de estruturação das comunidades de macroinvertebrados bentônicos. Palavras-chave: parâmetros biológicos, bioindicadores, áreas de proteção ambiental, impacto ambiental

    More resistant tendons obtained from the association of Heteropterys aphrodisiaca and endurance training

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    <p>Abstract</p> <p>Background</p> <p>Popular Brazilian medicine uses <it>Heteropterys aphrodisiaca </it>infusion as a tonic or stimulant, for the treatment of nervous debility and breakdown and for muscle and bone weakness. This study investigated the effects of <it>Heteropterys aphrodisiaca </it>infusion on the tendon properties and extracellular matrix of rats under endurance training.</p> <p>Methods</p> <p>Wistar rats were grouped as follows: CS- control sedentary, HS- <it>H. aphrodisiaca </it>sedentary, CT-control trained, HT- <it>H. aphrodisiaca </it>trained. The training protocol consisted in running on a motorized treadmill, five times a week, with weekly increase in treadmill speed and duration. Control groups received water while the HS and HT groups received <it>H. aphrodisiaca </it>infusion, daily, by gavage for the 8 weeks of training. Achilles tendons were frozen for biochemical and biomechanical analysis or preserved in Karnovsky's fixative, then processed for histomorphological analysis with light microscopy.</p> <p>Results</p> <p>Biomechanical analysis showed significant increase in maximum load, maximum stress, modulus of elasticity and stiffness of the HT animals' tendons. The metalloproteinase-2 activity was reduced in the HT group. The compression region of HT animals' tendons had a stronger and more intense metachromasy, which suggests an increase in glycosaminoglycan concentration in this region of the tendon. The most intense birefringence was observed in both compression and tension regions of HT animals' tendons, which may indicate a higher organizational level of collagen bundles. The hydroxyproline content increased in the HT group.</p> <p>Conclusions</p> <p>The association of endurance training with <it>H. aphrodisiaca </it>resulted in more organized collagen bundles and more resistant tendons to support higher loads from intense muscle contraction. Despite the clear anabolic effects of <it>Heteropterys aphrodisiaca </it>and the endurance exercise association, no side effects were observed, such as those found for synthetic anabolic androgenic steroids.</p

    Comparative descriptions of eggs from three species of Rhodnius (Hemiptera: Reduviidae: Triatominae)

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    The authors describe and compare the morphological and ultrastructural characteristics of eggs from the three most recent described species of the genus Rhodnius Stål, 1859, which have not previously been studied. These species are Rhodnius colombiensis (Mejia, Galvão & Jurberg 1999), Rhodnius milesi (Carcavallo, Rocha, Galvão & Jurberg 2001) and Rhodnius stali (Lent, Jurberg & Galvão 1993). The results revealed that there are similarities in the exochorial architecture of optical microscopy and scanning electron microscopy; these include the predominance of hexagonal cells that are common to all Rhodnius species and variable degrees of lateral flattening, which is common not only to species of this genus, but also to the Rhodniini tribe. Differences in overall colour, the presence of a collar in R. milesi, a longitudinal bevel in R. stali and the precise length of R. colombiensis can be useful distinguishing features. As a result of this study, the key for egg identification proposed by Barata in 1981 can be updated.European Community - Chagas Disease Intervention ActivitiesCNPqCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES
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