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1.
Materials (Basel) ; 13(10)2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32443686

RESUMO

Intrinsically conductive polymers (CPs) combine the inherent mechanical properties of organic polymers with charge transport, opto-electronic and redox properties that can be easily tuned up to those typical of semiconductors and metals. The control of the morphology at the nanoscale and the design of CP-based composite materials have expanded their multifunctional character even further. These virtues have been exploited to advantage in opto-electronic devices, energy-conversion and storage systems, sensors and actuators, and more recently in applications related to biomedical and separation science or adsorbents for pollutant removal. The special issue "Conductive Polymers: Materials and Applications" was compiled by gathering contributions that cover the latest advances in the field, with special emphasis upon emerging applications.

2.
Materials (Basel) ; 12(16)2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31394840

RESUMO

Electrochemical polymerization is known to be a suitable route to obtain conducting polymer-carbon composites uniformly covering the carbon support. In this work, we report the application of a filter-press electrochemical cell to polymerize polyaniline (PAni) on the surface of large-sized activated carbon cloth (ACC) by simple galvanostatic electropolymerization of an aniline-containing H2SO4 electrolyte. Flexible composites with different PAni loadings were synthesized by controlling the treatment time and characterized by means of Scanning Electron microscopy (SEM), X-Ray Photoelectron Spectroscopy (XPS), physical adsorption of gases, thermogravimetric analysis (TGA), cyclic voltammetry and direct current (DC) conductivity measurements. PAni grows first as a thin film mostly deposited inside ACC micro- and mesoporosity. At prolonged electropolymerization time, the amount of deposited PAni rises sharply to form a brittle and porous, thick coating of nanofibrous or nanowire-shaped structures. Composites with low-loading PAni thin films show enhanced specific capacitance, lower sheet resistance and faster adsorption kinetics of Acid Red 27. Instead, thick nanofibrous coatings have a deleterious effect, which is attributed to a dramatic decrease in the specific surface area caused by strong pore blockage and to the occurrence of contact electrical resistance. Our results demonstrate that mass-production restrictions often claimed for electropolymerization can be easily overcome.

3.
Saudi J Ophthalmol ; 29(3): 227-31, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26155085

RESUMO

The drug dasatinib is a new therapeutic option for patients with chronic myeloid leukemia (CML) as well as acute lymphocytic lymphoblastic leukemia (ALL). However, the scientific literature has not reached a consensus regarding the types of secondary ophthalmologic effects that this drug may have. In this study, we present the case of a 36-year-old male patient who was treated with dasatinib. Two and a half months later, this patient began to experience progressive visual loss in the superior visual field of both eyes. After ruling out various diagnostic options and performing extensive complementary tests, the suspected diagnosis was compatible with optic neuropathy secondary to dasatinib. The patient partially improved after stopping this medication and receiving oral corticosteroid treatment. Although secondary ophthalmological effects related to dasatinib are practically non-existent, our case is the first to report optic neuropathy secondary to this drug.

4.
ACS Appl Mater Interfaces ; 6(24): 22778-89, 2014 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-25453898

RESUMO

Different Pt- and Ru-doped Ti/SnO2-Sb electrodes were synthesized by thermal decomposition. The effect of the gradual substitution of Sb by Ru in the nominal composition on the physicochemical and electrochemical properties were evaluated. The electrochemical stability of the electrodes was estimated from accelerated tests at 0.5 A cm(-2) in 1 M NaOH. Both as-synthesized and deactivated electrodes were thoroughly characterized by scanning electron microscopy (SEM), energy-dispersive X-ray microanalysis (EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction analysis (XRD). The incorporation of a small amount (about 3 at. %) of both Pt and Ru into the SnO2-Sb electrodes produced a 400-times increase in their service life in alkaline medium, with no remarkable change in the electrocatalysis of the oxygen evolution reaction (OER). It is concluded that the deactivation of the electrodes is promoted by alkaline dissolution of metal species and coating detachment at high potentials. The introduction of Pt has a coating compacting effect, and Ru(IV), at low amounts until 9.75 at. %, replaces the Sn(IV) cations in the rutile-like SnO2 structure to form a solid solution that strongly increases the stability of the electrodes. The observed Ru segregation and decreased stability for larger Ru contents (x > 9.75 at. %), together with the selective dissolution of Ru after deactivation, suggest that the formation of a homogeneous (RuδSn1-δ)O2 single-phase is crucial for the stabilization of these electrodes.

5.
ACS Appl Mater Interfaces ; 6(14): 11682-91, 2014 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-24955482

RESUMO

This paper presents a systematic study of the effect of the electrochemical treatment (galvanostatic electrolysis in a filter-press electrochemical cell) on the surface chemistry and porous texture of commercial activated carbon cloth. The same treatments have been conducted over a granular activated carbon in order to clarify the effect of morphology. The influence of different electrochemical variables, such as the electrode polarity (anodic or cathodic), the applied current (between 0.2 and 1.0 A) and the type of electrolyte (HNO3 and NaCl) have also been analyzed. The anodic treatment of both activated carbons causes an increase in the amount of surface oxygen groups, whereas the cathodic treatment does not produce any relevant modification of the surface chemistry. The HNO3 electrolyte produced a lower generation of oxygen groups than the NaCl one, but differences in the achieved distribution of surface groups can be benefitial to selectively tune the surface chemistry. The porous texture seems to be unaltered after the electro-oxidation treatment. The validity of this method to introduce surface oxygen groups with a pseudocapacitive behavior has been corroborated by cyclic voltammetry. As a conclusion, the electrochemical treatment can be easily implemented to selectively and quantitatively modify the surface chemistry of activated carbons with different shapes and morphologies.

6.
Clin Neurophysiol ; 123(11): 2205-11, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22621909

RESUMO

OBJECTIVES: To establish a methodology for mapping of primary motor cortex (M1) for cricothyroid (CTHY) muscles in a group of healthy subjects using three-dimensional (3D) magnetic resonance imaging (MRI) navigated transcranial magnetic stimulation (nTMS). METHODS: Two independent measurements were performed. Twelve right-handed healthy subjects were included in the study. In the first measurement, mapping of the abductor pollicis brevis (APB) muscle was followed by mapping of the M1 for CTHY. This was performed in 11 subjects. Second, to avoid bias concerning using a hand knob as a landmark, mapping of M1 for CTHY muscle was followed by mapping of M1 for APB. This was performed in three healthy subjects. The nTMS was used, with selective recordings of motor evoked potentials (MEPs) from APB muscle and corticobulbar motor evoked potentials (CoMEPs) from the CTHY muscle. For recording the responses from the CTHY muscle two hook wire electrodes (the size of 76 µm of diametre passing through 27 gauge needle) were inserted in the muscle. For the recording of MEPs from APB muscle, surface electrodes were used. RESULTS: First measurement: Stimulation over the left M1 for APB muscles elicits MEPs in the contralateral APB muscle with a mean latency of 22.8±1.69ms. Stimulation over the left M1 for the CTHY muscle elicits CoMEPs in the contralateral CTHY muscle with a mean latency of 11.89±1.26ms. The distance between the cortical representation for APB and CTHY was 25.19±6.52mm, with CTHY muscle representation lateral to the APB muscle. Second measurement: The results of second measurement of the distance between M1 for CTHY and M1 for APB and their cortical localisation were comparable to the results of the first measurement. CONCLUSION: This is the first study with the aim to determine the exact cortical localisation of CTHY muscle with nTMS. Mapping of M1 for CTHY and APB muscles by nTMS was successfully performed in all healthy subjects. The exact location of the stimulating points over M1 muscles eliciting responses in CTHY and APB muscles was determined and superimposed over 3D MRI images. The data show that M1 for CTHY muscle is about 25mm more lateral with regard to M1 for the APB muscle. SIGNIFICANCE: Mapping of M1 for CTHY muscle might represent an important neurophysiologic marker for facilitating preoperative mapping of motor speech-related cortical areas due to the proximity of motor cortical representation for laryngeal muscles and opercular part of the Broca area.


Assuntos
Mapeamento Encefálico/métodos , Músculos Laríngeos/inervação , Músculos Laríngeos/fisiologia , Córtex Motor/fisiologia , Estimulação Magnética Transcraniana/métodos , Adulto , Idoso , Estimulação Elétrica/métodos , Potencial Evocado Motor/fisiologia , Feminino , Mãos , Humanos , Músculos Laríngeos/patologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Córtex Motor/patologia , Músculo Esquelético/inervação , Músculo Esquelético/patologia , Músculo Esquelético/fisiologia
7.
Rev. argent. neurocir ; 29(2): 65-75, jun. 2015. ilus
Artigo em Espanhol | LILACS | ID: biblio-835740

RESUMO

Introducción: la estimulación cortical directa (DCS) es una metodología corrientemente usada para localizar áreas del lenguaje en intervenciones quirúrgicas que incluyan resecciones.La estimulación magnética transcraneana repetitiva (rTMS) a demostrado también su capacidad para inducir alteraciones transitorias. Recientemente el desarrollo del Sistema de Navegación de TMS asegura precisa localización del sitio estimulado. El objetivo del trabajo es estudiar la confiabilidad de la estimulación magnética transcraneal repetitiva navegada (nrTMS) en la localización de los sitios del lenguaje. Métodos: Once pacientes seleccionados para mapeo del lenguaje por DCS fueron evaluados pre-cirugía con nrTMS. Los mapeos de lenguaje prequirúrgicos mediante nrTMS fueron comparados con DCS. Resultados: Un total de 25 nrTMS sitios del lenguaje y 38 DCS fueron localizados. La sensibilidad y la especificidad obtenida fue de 88.4 y 95.6, respectivamente. La distancia media fue evaluada en 4,5mm. Conclusiones: Los dispositivos de nrTMS permiten la identificación de las áreas corticales del lenguaje. Con un alto grado de concordancia con el mapeo TMS. La nrTMS se muestra como una herramienta de interés en la investigación y aplicación práctica en la función del lenguaje.


Introduction: direct cortical stimulation (DCS) is currently used to localise language areas in surgical resections. Repetitive transcranial magnetic stimulation (rTMS) has also shown its capacity to induce transient language alterations. Newly developed Navigated Brain Systems of TMS ensure precise topographical localisation of the stimulated site. The objective was to study the reliability of navigated repetitive transcranial magnetic stimulation (nrTMS) in language sites localisation.Methods: Eleven patients selected for DCS language mapping were presurgically evaluated with nrTMS. These presurgicalnrTMS language maps were then compared with DCS.Results: A total number of 25 nrTMS and 38 DCS language sites were localised. Sensitivity and specificity were calculated as 88.4 and 95.6 respectively. Mean distance was assessed as 4.5 millimetres. Conclusions: nrTMS devices allow identification of cortical language areas, with a high degree of concordance to TMS mapping. NrTMS shows up as an interesting tool for research and practical application in language function.


Assuntos
Estimulação Encefálica Profunda , Transtornos do Desenvolvimento da Linguagem , Malformações do Desenvolvimento Cortical
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