5 resultados para Coexisting
em Instituto Politécnico do Porto, Portugal
Resumo:
Wireless Body Area Network (WBAN) is the most convenient, cost-effective, accurate, and non-invasive technology for e-health monitoring. The performance of WBAN may be disturbed when coexisting with other wireless networks. Accordingly, this paper provides a comprehensive study and in-depth analysis of coexistence issues and interference mitigation solutions in WBAN technologies. A thorough survey of state-of-the art research in WBAN coexistence issues is conducted. The survey classified, discussed, and compared the studies according to the parameters used to analyze the coexistence problem. Solutions suggested by the studies are then classified according to the followed techniques and concomitant shortcomings are identified. Moreover, the coexistence problem in WBAN technologies is mathematically analyzed and formulas are derived for the probability of successful channel access for different wireless technologies with the coexistence of an interfering network. Finally, extensive simulations are conducted using OPNET with several real-life scenarios to evaluate the impact of coexistence interference on different WBAN technologies. In particular, three main WBAN wireless technologies are considered: IEEE 802.15.6, IEEE 802.15.4, and low-power WiFi. The mathematical analysis and the simulation results are discussed and the impact of interfering network on the different wireless technologies is compared and analyzed. The results show that an interfering network (e.g., standard WiFi) has an impact on the performance of WBAN and may disrupt its operation. In addition, using low-power WiFi for WBANs is investigated and proved to be a feasible option compared to other wireless technologies.
Resumo:
This work uses surface imprinting to design a novel smart plastic antibodymaterial (SPAM) for Haemoglobin (Hb). Charged binding sites are described here for the first time to tailor plastic antibody nanostructures for a large size protein such as Hb. Its application to design small, portable and low cost potentiometric devices is presented. The SPAM material was obtained by linking Hb to silica nanoparticles and allowing its ionic interaction with charged vinyl monomers. A neutral polymeric matrix was created around these and the imprinted protein removed. Additional materials were designed in parallel acting as a control: a neutral imprinted material (NSPAM), obtained by removing the charged monomers from the procedure, and the Non-Imprinted (NI) versions of SPAM and NSPAM by removing the template. SEM analysis confirmed the surface modification of the silica nanoparticles. All materials were mixed with PVC/plasticizer and applied as selective membranes in potentiometric transduction. Electromotive force (emf) variations were detected only for selective membranes having a lipophilic anionic additive in the membrane. The presence of Hb inside these membranes was evident and confirmed by FTIR, optical microscopy and Raman spectroscopy. The best performance was found for SPAM-based selective membranes with an anionic lipophilic additive, at pH 5. The limits of detection were 43.8 mg mL 1 and linear responses were obtained down to 83.8 mg mL 1, with an average cationic slope of +40 mV per decade. Good selectivity was also observed against other coexisting biomolecules. The analytical application was conducted successfully, showing accurate and precise results.
Resumo:
A gold screen printed electrode (Au-SPE) was modified by merging Molecular Imprinting and Self-Assembly Monolayer techniques for fast screening cardiac biomarkers in point-of-care (POC). For this purpose, Myoglobin (Myo) was selected as target analyte and its plastic antibody imprinted over a glutaraldehyde (Glu)/cysteamine (Cys) layer on the gold-surface. The imprinting effect was produced by growing a reticulated polymer of acrylamide (AAM) and N,N′-methylenebisacrylamide (NNMBA) around the Myo template, covalently attached to the biosensing surface. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) studies were carried out in all chemical modification steps to confirm the surface changes in the Au-SPE. The analytical features of the resulting biosensor were studied by different electrochemical techniques, including EIS, square wave voltammetry (SWV) and potentiometry. The limits of detection ranged from 0.13 to 8 μg/mL. Only potentiometry assays showed limits of detection including the cut-off Myo levels. Quantitative information was also produced for Myo concentrations ≥0.2 μg/mL. The linear response of the biosensing device showed an anionic slope of ~70 mV per decade molar concentration up to 0.3 μg/mL. The interference of coexisting species was tested and good selectivity was observed. The biosensor was successfully applied to biological fluids.
Resumo:
JORNADAS DE ELECTROQUÍMICA E INOVAÇÃO 2013
Resumo:
Partindo dos princípios que norteiam a UMUM, não esquecendo os pontos de referência da evolução transdisciplinar da educação – partir da/para a realidade – e tendo em mente que a estrutura student oriented sustenta a organização dos cursos, problematizamos a opção pela oferta, no 1º ano da licenciatura, de um conjunto de quatro disciplinas curriculares transversais a todos os cursos. Cientes de que a educação implica a vivência da interculturalidade e a inclusão social, o alvo é identificar o papel que a língua desempenha na descoberta do ‘eu’, na sua aceitação e consolidação, para que seja viável comunicar, agir e (con)viver em sociedade; na vivência pacífica do ‘eu’ com o ‘outro’; na construção colaborativa dos saberes e dos saberes fazeres. Daí decorre que as disciplinas curriculares transversais escolhidas, para induzir e potenciar uma educação de qualidade, tenham sido o Português, enquanto língua oficial, o Inglês, enquanto língua franca, as Tecnologias da Informação e Comunicação, como mediadoras da comunicação, promotoras de redes e de comunidades de aprendizagem para a construção do conhecimento e, ainda, Diálogos, Paz e Desenvolvimento, propiciando uma emergência equilibrada do sujeito per se, na sua relação com o ‘outro’ e com o mundo – saber ser e saber conviver. Questionamos a metodologia a utilizar nestas disciplinas curriculares, respeitando as suas especificidades, sustentando as áreas científicas contempladas em cada curso, numa dinâmica inter/transdisciplinar, implicando os estudantes na realidade e na complexidade do conhecimento e, em complementaridade, desafiando os docentes para o trabalho colaborativo.