Tipos de implantes activos de oído medio

Active middle ear implants are classified as piezoelectric implants, which use the properties of piezoelectric materials. There are two types of piezoelectric implants: monomorphic and dimorphic; electromagnetic transduction uses a magnet, usually a rare earth magnet (e.g. samarium cobalt) and an energizing coil. This magnetic field causes the magnet to vibrate, which in turn, through the tympanic-ossicular chain, causes movement of the cochlear fluids. Electromechanical transduction is a variation of electromagnetic transduction

Projeto tecnologias sociais para a gestão da água ? TSGA: contribuição para a gestão participativa da água.

Projeto: 06.09.06.001

Multi-national perceptions on challenges, opportunities, and support structures for Dual Career migrations in European studentathletes

Despite Dual Careers (sports and education) and mobility of students being priorities in the funding policies of the European Commission, migrating student-athletes report severe challenges and decreased performance or dropouts at sport and academic levels. The objective of this study was to depict and assess the perceptions on challenges, support services, and their effectiveness in consideration of specific characteristics of participants and migrations. Based on a meta-synthesis and previous findings, a 50-items questionnaire was developed and completed by 245 student-athletes in 5 European countries. Participants with Dual Careers migration experience (n = 140) were considered for analyses of qualitative and quantitative (ordinal 5pt-Likert-scaled and metric) data on the Dual Career status, migration characteristics, received services, and outcomes. Chi-square-tests were conducted for differences between countries and genders at a significance level of p < .05. Country-related differences were found for experiences and intentions to migrate (X2(12) = 50.52, p<0.001), duration of the migration (X2(16) = 38.20, p = 0.001), financial support (X2(8) = 29.87, p<0.001), and decreased performances in academics (X2(16) = 56.12, p<0.001) and sports (X2(16) = 31.79, p = 0.01). Gender-related difference emerged in financial support (X2(4) = 10.68, p = 0.03), duration of the migration (X2(4) = 14.56, p = 0.01), and decreased academic performance (X2(4) = 10.57, p = 0.03). Tutoring and counselling support was ranked as the most effective support, especially when received from the academic field (4.0±1.0 pt) and others (4.1±0.8 pt), followed by online services from sport and academic sectors (both: 3.9±0.9 pt). Considering the pervasive globalization of sport and education, Dual Career migration can contribute to the development of a European sport culture. The high ratio of migrating student-athletes underlines the relevance of migrations in the field of Dual Careers. This study contributes to the literature by adding insights on practices, challenges, supports, and outcomes perceived by student-athletes migrating in Europe. Moreover, country- and gender-related differences support the consideration of specific characteristics and reveal critical factors in specific target groups. The findings contribute to identifying requirements and effective support measures in Dual Career migrations and can be used to improve support services

Performance Analysis of Signaling Delay for Wireless Cellular Networks

In wireless cellular networks, signaling traffic such as location update, paging and handoff due to the user\u27s mobility takes a considerable portion of the total traffic load. In addition, the maximum allowable delays may be different among the signaling packets. In this paper, we present an analytical model for evaluating a total processing delay of signaling packets of wireless cellular networks, which integrates the delays of the radio channel and the processing delay at the wired portion. Through numerical examples, we show that priority processing is effective for reducing the handoff processing delays. We also evaluate the delay difference among cells according to their position within the location area, and the influence of number of terminals upon the processing delays

Weak selection and stability of localized distributions in Ostwald ripening

We support and generalize a weak selection rule predicted recently for the self-similar asymptotics of the distribution function (DF) in the zero-volume-fraction limit of Ostwald ripening (OR). An asymptotic perturbation theory is developed that, when combined with an exact invariance property of the system, yields the selection rule, predicts a power-law convergence towards the selected self-similar DF and agrees well with our numerical simulations for the interface- and diffusion-controlled OR.Comment: 4 pages, 2 figures, submitted to PR

First Measurement of Coherent Elastic Neutrino-Nucleus Scattering on Argon

We report the first measurement of coherent elastic neutrino-nucleus scattering (\cevns) on argon using a liquid argon detector at the Oak Ridge National Laboratory Spallation Neutron Source. Two independent analyses prefer \cevns over the background-only null hypothesis with greater than $3\sigma$ significance. The measured cross section, averaged over the incident neutrino flux, is (2.2 $\pm$ 0.7) $\times$10$^{-39}$ cm$^2$ -- consistent with the standard model prediction. The neutron-number dependence of this result, together with that from our previous measurement on CsI, confirms the existence of the \cevns process and provides improved constraints on non-standard neutrino interactions.Comment: 8 pages, 5 figures with 2 pages, 6 figures supplementary material V3: fixes to figs 3,4 V4: fix typo in table 1, V5: replaced missing appendix, V6: fix Eq 1, new fig 3, V7 final version, updated with final revision

Determination of the melting temperature, heat of fusion, and purity analysis of different samples of zidovudine (AZT) using DSC

The determination of chemical purity, melting range, and variation of enthalpy in the process of characterizing medicines is one of the principal requirements evaluated in quality control of the pharmaceutical industry. In this study, the method of purity determination using DSC was outlined, as well as the application of this technique for the evaluation of commercial samples of zidovudine (AZT) (raw material) supplied by different laboratories. To this end, samples from six different laboratories (A, B, C, D, E, and F) and the standard reference (R) from the United States Pharmacopeia (USP) were analyzed. The DSC curves were obtained in the temperature range of 25 to 200 ºC under the dynamic atmosphere of N2 (50 mL min-1), heating rate of β=2 ºC min-1, using an Al capsule containing approximately 2 mg of sample material. The results demonstrated that the standard reference presented a proportion of 99.83% whereas the AZT samples presented a variation ranging from 97.59 to 99.54%. In addition, the standard reference was found to present a temperature of onset of melting point of 122.80 °C. Regarding the samples of active agents provided by the different laboratories, a variation ranging from 118.70 to 122.87 °C was measured. In terms of ΔHm, the samples presented an average value of 31.12 kJ mol-1._________________________________________________________________________________________ RESUMO: A determinação da pureza química, a faixa de fusão e a variação de entalpia envolvida no processo de caracterização de fármacos é um dos principais requisitos avaliados no controle de qualidade em indústrias farmacêuticas. Neste trabalho é feita uma breve abordagem sobre o método de determinação de pureza utilizando DSC, assim como a aplicação desta técnica para avaliação de amostras comerciais de zidovudina (AZT) (matéria-prima) fornecida por diferentes laboratórios. Para tal, foram analisadas amostras de seis diferentes laboratórios (A,B,C,D,E e F) e a substância química de referência (R) da United States Pharmacopeia (USP). As curvas DSC foram obtidas na faixa de temperatura entre 25 a 200 ºC, sob atmosfera dinâmica de N2 (50 mL min-1), β=2 ºC min-1, utilizando cápsula de Al contendo aproximadamente 2 mg de amostra. De acordo com os resultados, pode-se observar que a substância química de referência apresentou teor igual a 99,83% e que as amostras de AZT apresentaram uma faixa de variação entre 97,59 e 99,54%. Pode-se verificar, ainda, que a substância química de referência apresentou uma temperatura onset de fusão igual a 122,80 °C. Para as amostras dos princípios ativos fornecidos pelos diferentes laboratórios, pode-se verificar uma faixa de variação entre 118,70 e 122,87 °C. No que se refere ao ΔHm, as amostras apresentaram valor médio de 31,12 kJ.mol-1

Treatment for hearing loss among the elderly: auditory outcomes and impact on quality of life

The study aim was to determine the benefit of cochlear im- plantation and hearing aids in older adults diagnosed with hearing loss and to evaluate the index of depression, anxiety and quality of life after such treatments. A retrospective co- hort comprised 117 patients older than 65 years and diag- nosed with moderate to profound hearing loss who were included and classified into 2 groups (treated vs. non-treat- ed). A battery of tests including auditory (pure-tone average, disyllabic words in quiet at 65 dB SPL) and findings from a series of questions relevant to quality of life were compared between both groups. Auditory outcomes for disyllabic words were 58.21% for the cochlear implant-treated group and 82.8% for the hearing aid-treated group. There was a positive effect on anxiety, depression, health status and quality of life in the cochlear implant group versus the pro- found hearing loss control group. We conclude that older adults with moderate to profound hearing loss gain benefit from hearing aids or cochlear implants not only in terms of improved hearing function, but also in terms of positive ef- fects on anxiety, depression, health status and quality of life