370 research outputs found

    Synthesis of nonseparable 3-D spatiotemporal bandpass filters on analog networks

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    On analog networks and mixed-domain spatio-temporal frequency response

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    A Wearable Multisensing Patch for Continuous Sweat Monitoring

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    In sport, exercise and healthcare settings, there is a need for continuous, non-invasive monitoring of biomarkers to assess human performance, health and wellbeing. Here we report the development of a flexible microfluidic platform with fully integrated sensing for on-body testing of human sweat. The system can simultaneously and selectively measure metabolite (e.g. lactate) and electrolytes (e.g. pH, sodium) together with temperature sensing for internal calibration. The construction of the platform is designed such that continuous flow of sweat can pass through an array of flexible microneedle type of sensors (50 µm diameter) incorporated in a microfluidic channel. Potentiometric sodium ion sensors were developed using a polyvinyl chloride (PVC) functional membrane deposited on an electrochemically deposited internal layer of Poly(3,4-ethylenedioxythiophene) (PEDOT) polymer. The pH sensing layer is based on a highly sensitive membrane of iridium oxide (IrOx). The amperometric-based lactate sensor consists of doped enzymes deposited on top of a semipermeable copolymer mebrane and outer polyurethane layers. Real-time data were collected from human subjects during cycle ergometry and treadmill running. A detailed comparison of sodium, lactate and cortisol from saliva is reported, demonstrating the potential of the multi-sensing platform for tracking these outcomes. In summary, a fully integrated sensor for continuous, simultaneous and selective measurement of sweat metabolites, electrolytes and temperature was achieved using a flexible microfluidic platform. This system can also transmit information wirelessly for ease of collection and storage, with the potential for real-time data analytics

    Etiologies des pleurésies exsudatives: à propos de 424 cas à Madagascar

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    Introduction: La pleurésie constitue un motif fréquent de consultation en pneumologie. Notre travail a pour objectif de déterminer les étiologies des pleurésies exsudatives afin d’en faciliter les démarches étiologiques. Méthodes: Il s’agit d’une étude rétrospective réalisée chez des patients ayant une pleurésie exsudative et bénéficiant une biopsie pleurale à l’aveugle à l’aide de l’aiguille de Castelain, pendant une période de 5 ans (2005 à 2009). Résultats: Parmi les 424 patients inclus, 259 hommes (61,08%) et 165 femmes (38,91%) étaient individualisés. Les pleurésies étaient d’origine tuberculeuse dans 298 cas (70, 28%), métastatique dans 63 cas (14,85%), inflammation non spécifique dans 51 cas (12,02%). Des fibres musculaires striées étaient biopsiées dans 12 cas (2,83%). Conclusion: La biopsie pleurale occupe une place prépondérante dans la recherche étiologique des pleurésies d'exsudatives à Madagascar où la tuberculose sévit encore en mode endémique.Key words: Tuberculose pleurale, biopsie pleurale, tumeurs pleurales, pleurésies d’exsudative

    Factors contributing to the temperature beneath plaster or fiberglass cast material

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    <p>Abstract</p> <p>Background</p> <p>Most cast materials mature and harden via an exothermic reaction. Although rare, thermal injuries secondary to casting can occur. The purpose of this study was to evaluate factors that contribute to the elevated temperature beneath a cast and, more specifically, evaluate the differences of modern casting materials including fiberglass and prefabricated splints.</p> <p>Methods</p> <p>The temperature beneath various types (plaster, fiberglass, and fiberglass splints), brands, and thickness of cast material were measured after they were applied over thermometer which was on the surface of a single diameter and thickness PVC tube. A single layer of cotton stockinette with variable layers and types of cast padding were placed prior to application of the cast. Serial temperature measurements were made as the cast matured and reached peak temperature. Time to peak, duration of peak, and peak temperature were noted. Additional tests included varying the dip water temperature and assessing external insulating factors. Ambient temperature, ambient humidity and dip water freshness were controlled.</p> <p>Results</p> <p>Outcomes revealed that material type, cast thickness, and dip water temperature played key roles regarding the temperature beneath the cast. Faster setting plasters achieved peak temperature quicker and at a higher level than slower setting plasters. Thicker fiberglass and plaster casts led to greater peak temperature levels. Likewise increasing dip-water temperature led to elevated temperatures. The thickness and type of cast padding had less of an effect for all materials. With a definition of thermal injury risk of skin injury being greater than 49 degrees Celsius, we found that thick casts of extra fast setting plaster consistently approached dangerous levels (greater than 49 degrees for an extended period). Indeed a cast of extra-fast setting plaster, 20 layers thick, placed on a pillow during maturation maintained temperatures over 50 degrees of Celsius for over 20 minutes.</p> <p>Conclusion</p> <p>Clinicians should be cautious when applying thick casts with warm dip water. Fast setting plasters have increased risk of thermal injury while brand does not appear to play a significant role. Prefabricated fiberglass splints appear to be safer than circumferential casts. The greatest risk of thermal injury occurs when thick casts are allowed to mature while resting on pillow.</p

    A three-phase bidirectional variable speed drive: an experimental validation for a three-phase induction motor

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    This paper presents the implementation and subsequent experimental verification of an electronic variable speed drive (VSD) for driving an induction motor, which is composed by a three-phase ac-dc converter on the grid-side and by a three-phase dc-ac converter on the motor-side. With the proposed solution, besides driving the motor, it is possible to mitigate power quality problems on the grid-side (e.g., current harmonics and power factor) associated with the use of diode-bridge ac-dc converters in the conventional VSDs. Besides, with the proposed solution, a bidirectional operation is possible, allowing to deliver to the power grid the energy generated in motor braking processes. As demonstrated along the paper, with the proposed VSD, it is possible to control the motor speed (including the rotation direction), and the operation with sinusoidal currents and unitary power factor on the grid-side. A laboratory prototype was developed, permitting to perform an experimental validation and prove the main functionalities of the VSD.This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2019. This work has been supported by the FCT Project DAIPESEV PTDC/EEI-EEE/30382/2017, and by the FCT Project QUALITY4POWER PTDC/EEI-EEE/28813/2017

    Determining the most appropriate printing techniques for digital printing to achieve printing quality of Teslin polymers

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    Some documents in the Arab Republic of Egypt face a great challenge, which is the problem of short life span, and it is worth noting here that the global trend and also in the Arab Republic of Egypt recently is moving towards the use of polymers as an alternative to traditional paper materials in many important documents, and therefore the research has addressed the possibility of printing on raw materials. Teslin polymers, facing many challenges, including print quality when printed on any of the digital printing techniques in terms of determining the most appropriate digital techniques for printing on plastic Teslin material to obtain the required print quality by measuring both (Lab values of colour, density, dot gain and trapping). And to achieve this goal, this research has dealt with the theoretical, practical and analytical study of both the raw material that has been experimented with and the digital printing techniques used in the practical experiments of printing on the Teslin material, which is an inkjet technique using the Com Color GD 9630 Riso printer, and the dry electro photographic technique using Library printers with limited production, which is the HP Color LaserJet Enterprise M553 printer, and also the dry electro photographic technology using quantum production (mass production) printers a Ricoh C7200 SL printer, and liquid electrophotography technology was used using the HP Indigo 7800 printer, and the study concluded that The most suitable technology for digital printing on the two-fold material is the Dry electrophotography technology using limited-production library printers, which is the HP Color LaserJet Enterprise M553, and also dry electrophotography technology using quantum printers, which is the Ricoh C7200 SL, and that inkjet technology using the Com Color GD 9630 Riso printer is not suitable for printing

    Rate and rhythm control treatment in the elderly and very elderly patients with atrial fibrillation: an observational cohort study of 1,497 patients

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    Stroke prevention and rate or rhythm control are crucial in the management of atrial fibrillation (AF). There is recent evidence for benefit of early rhythm control, yet rate control is the first choice in elderly patients. However, the efficacy and safety of rate and rhythm control in the elderly population remains largely unexplored. Therefore, we analyzed electronic health record data and investigated prescribing patterns and mortality of both strategies in elderly patients with AF. Data from patients with AF who were aged ≥75 years, used a pharmacological rate or rhythm control strategy, and visited Cardiology Centers of the Netherlands between 2007 and 2018 were extracted. Of the 1497 patients (54% female), 316 (21%) were prescribed rhythm control and 1181 (79%) rate control. Patients aged >85 years (OR: 2.28; 95% CI: 1.51-3.44, P< 0.001) and those with permanent AF (OR: 2.71; 95% CI: 1.67-4.41, P< 0.001) were more likely to receive rate control, whereas those with paroxysmal AF were less likely to receive rate control (OR: 0.42; 95% CI: 0.32-0.56, P< 0.001). After correction for relevant confounders, the mortality risk for patients using rhythm control and patients using rate control was similar (HR: 0.89; 95% CI: 0.70-1.12, P = 0.31). A more liberal approach towards prescribing a rhythm control strategy to the elderly patients with AF may be warranted and seems safe. Our data underscore the need for prospective studies to provide definite answers on efficacy and safety of rhythm control in elderly patients with AF
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