3,022 research outputs found

    Cardiac Troponin T and Illness Severity in the Very-Low-Birth-Weight Infant

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    Introduction. Respiratory distress are very common in Very-low-birth-weight (VLBW) infants and Myocardial injury may play a role in the disease outcome. Cardiac troponin T (cTnT) is the most useful marker of injury in adult population, but has not been extensively studied in this population. Aim. To study the role of cTnT in VLBW infants and its association with clinical outcomes. Methods. All VLBW infants admitted to our NICU were included in the study. Echocardiography and blood samples for cTnT determination were collected at 24 and 48 hours of life, and values >0.1 ng/mL were considered CTnT-positive values. Results. A total of 116 neonates had their blood samples collected. The median cTnT concentration within 24 hours was 0.191 (0.1–0.79) ng/mL and within 48 hours was 0.293 (0.1–1.0) ng/mL. A logistic regression analysis showed that PDA, low GA, and use of dopamine were independently associated with positive cTnT and abnormal Dopplerfluxometry and diuretics use had protective effects and was independently associated with troponin values. Conclusion. We observed a high prevalence of positivecTnT values in VLBW infants associated with illness severity. Our findings suggest that cTnT may be a useful and early marker of myocardial injury in VLBW infants

    Conjugated linoleic acid reduces permeability and fluidity of adipose plasma membranes from obese Zucker rats

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    NOTICE: this is the author’s version of a work that was accepted for publication in Biochemical and Biophysical Research Communications. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Biochemical and Biophysical Research Communications. July 2010; 398 (2): 199-204.Conjugated linoleic acid (CLA) is a dietary fatty acid frequently used as a body fat reducing agent whose effects upon cell membranes and cellular function remain unknown. Obese Zucker rats were fed atherogenic diets containing saturated fats of vegetable or animal origin with or without 1% CLA, as a mixture of cis(c)9,trans(t)11 and t10,c12 isomers. Plasma membrane vesicles obtained from visceral adi- pose tissue were used to assess the effectiveness of dietary fat and CLA membrane incorporation and its outcome on fluidity and permeability to water and glycerol. A significant decrease in adipose membrane fluidity was correlated with the changes observed in permeability, which seem to be caused by the incor- poration of the t10,c12 CLA isomer into membrane phospholipids. These results indicate that CLA supple- mentation in obese Zucker rats fed saturated and cholesterol rich diets reduces the fluidity and permeability of adipose membranes, therefore not supporting CLA as a body fat reducing agent through membrane fluidification in obese fat consumers

    Longitudinal study in 3,000 m male runners: relationship between performance and selected physiological parameters

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    The purpose of the present study was to analyze longitudinal changes in 3,000 m running performance and the relationship with selected physiological parameters. Eighteen well-trained male middle-distance runners were measured six times (x3 per year) throughout two consecutive competitive seasons. The following parameters were measured on each occasion: maximal oxygen uptake (VO2max), running economy (RE), velocity at maximal oxygen uptake (vVO2max), velocity at 4mmol L-1 blood lactate concentration (V4), and performance velocity (km·h-1) in 3,000 m time trials. Values ranged from 19.59 to 20.16 km·h-1, running performance; 197 to 207 mL·kg-1·km-1. RE; 17.2 to 17.7 km·h-1, V4; 67.1 to 72.5 mL·kg-1·min-1, VO2max; and 19.8 to 20.2 km·h-1, vVO2max. A hierarchical linear model was used to quantify longitudinal relationships between running performance and selected physiological variables. Running performance decreased significantly over time, between each time point the decrease in running velocity was 0.06 km·h-1. The variables that significantly explained performance changes were V4 and vVO2max. Also, vVO2max and V4 were the measures most strongly correlated with performance and can be used to predict 3,000 m race velocity. The best prediction formula for 3,000 m running performance was: y = 0.646 + 0.626x + 0.416z (R2=0.85); where y = V3,000 m velocity (km·h-1), x = V4 (km·h-1) and z = vVO2max (km·h-1). The high predictive power of vVO2max and V4 suggest that both coaches and athletes should give attention to improving these two physiological variables, in order to improve running performance

    The effects of beating, web forming and sizing on the surface energy of Eucalyptus globulus kraft fibres evaluated by inverse gas chromatography

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    In this work attention has been focused on the effects of papermaking beating, web forming and sizing operations on the physical/chemical surface properties of bleached Eucalyptus globulus kraft fibres. Inverse gas chromatography (IGC) was used to determine the dispersive component of surface tension (cs d) as well as the acidic/basic character (according to the Lewis concept) of the solid surfaces (pulp fibres and pulp handsheets). The results have shown that the main effect of beating is to increase the fibre’s Lewis acidic character. Web forming caused a strong decrease in cs d and significant increments in the adhesion works of both acidic and basic probes, lowering the ratio between the two. Nevertheless, the surface of handsheets still exhibited a dominant acidic character. The sizing operation did not change the dispersive component of the surface tension significantly but decreased the difference between the adhesion works of the acidic and basic probes, rendering the handsheet surface less Lewis acidic and more Lewis basic. Thus, although internal sizing is expected to strongly influence liquid spreading at the paper surface and liquid penetration of the fibre’s network, it is concluded that beating and web forming lead to important changes in the surface energetic properties of the Eucalyptus globulus kraft fibres

    Exploiting Template Metaprogramming to customize an object-oriented operating system

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    Nowadays, the growing complexity of embedded systems demands for configurability, variability and reuse. Conditional compilation and object-orientation are two of the most applied approaches in the management of system variability. While the former increases the code management complexity, the latter leverages the needed modularity and adaptability to simplify the development of reusable and customizable software at the expense of performance and memory penalty. This paper shows how C++ TMP (Template Metaprogramming) can be applied to manage the variability of an object-oriented operating system and at the same time get ride out of the performance and memory footprint overhead. In doing so, it will be statically generated only the desired functionalities, thus ensuring that code is optimized and adjusted to application requirements and hardware resources.Fundação para a Ciência e a Tecnologia (FCT

    Bot’n roll robotic kit as a learning tool for youngsters

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    Activities involving robotics, projecting assembling and programming robots are in essence hands-on and inquiry-based activities leading to an effective learning of different aspects of science and technology among others. Different approaches have being used to introduce robotics in the education of young children. In this communication we will present an approach that in an inquiry based science education, IBSE, perspective, uses an informal environment to introduced robotics, as well as a range of other science and technology, concepts and competencies to young students. Many youngsters are getting interested on general technology and the robotics field in particular. Even though their knowledge is very basic they are very enthusiastic and willing to learn quickly. Most robotics events consist of competitions, and that means the youngsters still need guidance by professionals. RoboParty is a different educational robotics event that teaches the participants, with IBSE hands-on techniques, how to build a robot from scratch to program it and in the end they keep the robot they built for themselves for further exploration. Such robot to be built by the young children for the first time needs to be very easy and with a friendly programming language. The Bot’n Roll robotics kit was developed specifically for the RoboParty event, and has since then been improved with more sensors and actuators, which are simple to built and easy to use. The Bot’n Roll robot family launched recently another more complex robot that uses omnidirectional wheels and that can be used on other robotic competitions like world known RoboCup. This paper describes also the Bot’n Roll robots and show how they are built, bearing in mind that these robots were developed for youngsters who never worked with robotics

    Net heart rate to prescribe physical activity in middle-aged to older active adults

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    This study had a twofold purpose: i) to develop a regression equation to estimate metabolic equivalent (MET) in walk/run by heart rate increment above rest (NetHR), and; ii) to determine NetHR thresholds for light, moderate, and vigorous physical activity (PA), from middle aged to elderly. Sample 1 (prediction sample) comprised 39 subjects (19 male and 20 female), with 58.2 ± 11.0 years old. Sample 2 (validation sample) comprised 40 subjects (18 male and 22 female) with 63.3 ± 7.0 years old. Each participant did the following activities in sequence, a 15min rest period in supine position, walk at 3km/h, walk at 4.5km/h, and walk at 6km/h, for 6 min at each walk velocity interval. The oxygen up-take (VO2) and heart rate (HR) were continuously and simultaneously assessed. A hierarchical linear model was used to analyze the relationship between metabolic equivalent (MET) and NetHR. The regression equation for MET prediction was: MET = 1.265780 + 0.109479 NetHR. The NetHR thresholds (upper limit) for light, moderate and vigorous PA were 16 and 35 and 70 bpm, respectively. NetHR is a practical, valid and non-invasive method to prescribe physical activity, taking in account individual characteristics (HR at rest combined with NetHR) in middle-aged to older adults

    Ethyl 7-Acetyl-8a-methyl-3-(1-phenyl-1H-tetrazol-5-yl)-1,4,4a,5,6,8a-hexahydro-7H-pyrano[2,3-c]pyridazine-1-carboxylate

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    The Diels–Alder reaction of ethyl 3-(1-phenyl-1H-tetrazol-5-yl-1,2-diaza-1,3-butadiene-1-carboxylate with 2-acetyl-6-methyl-2,3-dihydro-4H-pyran (methyl vinyl ketone dimer) regioselectively afforded the corresponding 3-(tetrazol-5-yl)-hexahydro-7H-pyrano[2,3-c]pyridazine in quantitative yield. An X-ray crystal structure of this cycloadduct is reported.info:eu-repo/semantics/publishedVersio

    Evaluation of the potential of collagen from codfish skin as a biomaterial for biomedical applications

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    Collagen is one of the most widely used biomaterials, not only due its biocompatibility, biodegradability and weak antigenic potential, but also due to its role in the structure and function of tissues. Searching for alternative collagen sources, the aim of this study was to extract collagen from the skin of codfish, previously obtained as a by-product of fish industrial plants, and characterize it regarding its use as a biomaterial for biomedical application, according to American Society for Testing and Materials (ASTM) Guidelines. Collagen type I with a high degree of purity was obtained through acid-extraction, as confirmed by colorimetric assays, SDS-PAGE and amino acid composition. Thermal analysis revealed a denaturing temperature around 16 C. Moreover, collagen showed a concentration-dependent effect in metabolism and on cell adhesion of lung fibroblast MRC-5 cells. In conclusion, this study shows that collagen can be obtained from marine-origin sources, while preserving its bioactivity, supporting its use in biomedical applications.European Research Council grant agreement ERC-2012-ADG 20120216-321266 for the project ComplexiTEinfo:eu-repo/semantics/publishedVersio

    Physical properties of some rocks from Hurd Peninsula (Livingston Island, Maritime Antarctica)

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    Estudo das propriedades físicas de algumas rochas da Península de Hurd (Ilha Livingston, Antárctida Marítima) Physical properties of some rocks from Hurd Peninsula (Livingston Island, Maritime Antarctica) P. M. Amaral1 *, A. Correia1, G. Vieira2, M. Ramos3, A. Trindade2, J. Carrilho4 1 Universidade de Évora, Departamento de Física, Centro de Geofísica de Évora, Évora, Portugal. 2 Universidade de Lisboa, Centro de Estudos Geográficos, Lisboa, Portugal. 3 Universidade de Alcalá, Departamento de Física, Madrid, Espanha. 4 Universidade de Évora, Departamento de Geociências, Évora, Portugal. * [email protected] Resumo: A distribuição do permafrost e da camada activa são afectados pelas alterações climáticas. Para diagnosticar e modelar este efeito é necessário monitorizar o regime térmico do solo e obter os valores das propriedades termofísicas do solo (condutividade térmica e difusividade térmica), essenciais para compreender como ocorre a transferência de energia térmica entre a atmosfera e as camadas mais superficiais do solo. Foram realizadas cinco sondagens na Península de Hurd (Ilha Livingston, Antárctida Marítima) com recolha de testemunhos e instalação de termistores. São apresentados os valores de várias propriedades físicas de rochas medidas (condutividade térmica, difusividade térmica, porosidade, massa volúmica, velocidade de ondas P e produção de calor) e uma breve descrição litológica da zona onde os furos foram realizados. Palavras-chave: Propriedades físicas de rochas, permafrost, Península Antárctica Abstract: The permafrost and the active layer distribution are affected by climate change. To diagnose and model this effect is necessary to monitor the thermal regime of the soil and determine the values of the thermophysical properties of the soil (thermal conductivity and thermal diffusivity), which are essential to understand the energy balance between the atmosphere and uppermost ground. Cores were collected and chains of thermistors installed in five boreholes in the Hurd Peninsula (Livingston Island, Maritime Antarctica). The main lithology and values of various physical properties of rocks are reported here (thermal conductivity, thermal diffusivity, porosity, density, P-wave velocity and heat production). Key-words: Physical properties of rocks, permafrost, Antarctica Peninsul
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