The "Contract" in Agostinho Neto's Poetry

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Understanding the Ion Jelly Conductivity Mechanism

The properties of the light flexible device, ion jelly, which combines gelatin with an ionic liquid (IL) were recently reported being promising to develop safe and highly conductive electrolytes. This article aims for the understanding of the ion jelly conductive mechanism using dielectric relaxation spectroscopy (DRS) in the frequency range 10(-1)-10(6) Hz; the study was complemented with differential scanning calorimetry (DSC) and pulsed field gradient nuclear magnetic resonance (PFG NMR) spectroscopy. The room temperature ionic liquid 1-butyl-3-methylimmidazolium dicyanamide (BMIMDCA) used as received (1.9% w/w water content) and with 6.6% (w/w) of water content and two ion jellies with two different ratios BMIMDCA/gelatin/water % (w/w), IJ1 (41.1/46.7/12.2) and IJ3 (67.8/25.6/6.6), have been characterized. A glass transition was detected by DSC for all materials allowing for classifying them as glass formers. For the ionic liquid, it was observed that the glass transition temperature decreases with the increase of water content. While in subsequent calorimetric runs crystallization was observed for BMIMDCA with negligible water content, no crystallization was detected for any of the ion jelly materials upon themal cycling. To the dielectric spectra of all tested materials, both dipolar relaxation and conductivity contribute; at the lowest frequencies, electrode and interfacial polarization highly dominate. Conductivity, which manifests much more intensity relative to dipolar reorientations, strongly evidences subdiffusive ion dynamics at high frequencies. From dielectric measures, transport properties as mobility and diffusion coefficients were extracted. Data treatment was carried out in order to deconvolute the average diffusion coefficients estimated from dielectric data in its individual contributions of cations (D(+)) and anions (D(-)). The D(+) values thus obtained for IJ3, the ion jelly with the highest IL/gelatin ratio, cover a large temperature range up to room temperature and revealed excellent agreement with direct measurements from PFG NMR, obeying to the same VFT equation. For BMIMDCA(6.6%water), which has the same water amount as IJ3, the diffusion coefficients were only estimated from DRS measurements over a limited temperature range; however, a single VFT equation describes both DRS and PFG NMR data. Moreover, it was found that the diffusion coefficients and mobility are similar for the ionic liquid and IJ3, which points to a role of both water and gelatin weakening the contact ion pair, facilitating the translational motion of ions and promoting its dissociation; nevertheless, it is conceivable the existence of a critical composition of gelatin that leads to those properties. The VFT temperature dependence observed for the conductivity was found to be determined by a similar dependence of the mobility. Both conductivity and segmental motion revealed to be correlated as inferred by the relatively low values of the decoupling indexes. The obtained results show that ion jelly could be in fact a very promising material to design novel electrolytes for different electrochemical devices, having a performance close to the IL but presenting an additional stability regarding electrical measurements and resistance against crystallization relative to the bulk ionic liquid

Zigomicose nasofacial: relato de um caso do estado do Pará, Brasil Nasofacial zygomycosis: case report from Pará, Brazil

Um caso de zigomicose nasofacial, causado por Conidiobolus coronatus, é descrito em paciente de 64 anos, do sexo feminino, procedente de Barcarena, Estado do Pará. Trata-se de doença rara na Região Norte do país - a maioria dos casos brasileiros tem sido registrada em Estados da Região Nordeste -, e o achado confirma a ocorrência do agente no Estado do Pará. A resposta ao iodeto de potássio, droga administrada à paciente, logo após a comprovação do diagnóstico pelo isolamento do fungo, foi boa, com resolução parcial das lesões em algumas semanas. A paciente continua ainda em tratamento, tendo-se associado o itraconazol ao iodeto<br>A case of nasofacial zygomycosis in a 64-year-old female patient from Barcarena, State of Pará, is reported. This is the second time that the disease is recognized in Northern Brazil. The diagnosis was initially suspected by the direct observation of broad coenocytic hyphae in biopsy specimens of the nasal cavity mucosa. Later, the cause of the disease was confirmed by the mycologial and histopathological findings. Rapid response to the therapy with potassium iodide was achieved, without however a complete resolution of the lesions. The patient still remains under treatment, with itraconazole and iodid