Pt-decorated nanoporous gold for glucose electrooxidation in neutral and alkaline solutions

Exploiting electrocatalysts with high activity for glucose oxidation is of central importance for practical applications such as glucose fuel cell. Pt-decorated nanoporous gold (NPG-Pt), created by depositing a thin layer of Pt on NPG surface, was proposed as an active electrode for glucose electrooxidation in neutral and alkaline solutions. The structure and surface properties of NPG-Pt were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), and cyclic voltammetry (CV). The electrocatalytic activity toward glucose oxidation in neutral and alkaline solutions was evaluated, which was found to depend strongly on the surface structure of NPG-Pt. A direct glucose fuel cell (DGFC) was performed based on the novel membrane electrode materials. With a low precious metal load of less than 0.3 mg cm-2 Au and 60 μg cm-2 Pt in anode and commercial Pt/C in cathode, the performance of DGFC in alkaline is much better than that in neutral condition

Microwave assisted synthesis of barium zirconium titanate nanopowders

This article is closed access.The paper reports the synthesis, structural and high frequency dielectric properties of Ba(Zr x Ti1−x )O3,BZT, nanopowders where x = 0, 0.1, 0.2, 0.3. These powders were synthesized using both microwave assisted and conventional heating, with the former requiring lower temperature and shorter times compared to the latter, viz., 700 °C for 30 min versus 900 °C for 5 h. The synthesized nanopowders were characterized using X-ray diffraction, micro-Raman spectroscopy, transmission electron microscopy, BET surface area analysis, differential scanning calorimetry and high frequency dielectric measurements. All the microwave synthesized BZT compositions were found to have well crystallized, finer nanoparticles with less agglomeration and higher dielectric permittivity compared to the conventionally prepared powders. The rapidity and less demanding processing conditions associated with the microwave assisted method augers well for the general applicability of the technique for the production of nanocrystalline powders

Assessment of cognition using the Rao's Brief Repeatable Battery of Neuropsychological Tests on a group of Brazilian patients with multiple sclerosis

To assess the cognition of patients with multiple sclerosis (MS) using the Rao's Brief Repeatable Battery of Neuropsychological Tests (BRB-N). METHOD: BRB-N was translated and adapted for control subjects. Subsequently, it was applied to a group of patients with relapsing-remitting (RR) MS. RESULTS: The assessment on the healthy controls (n=47) showed that the correlation between tests on the same cognitive domain was high and that there was a five-factor solution that explained 90% of the total variance. Except for the Word List Generation subset of tests, the performance of patients with RRMS (n=39) was worse than that of the healthy controls. CONCLUSION: BRB-N is a relatively simple method to assess cognition of patients with MS in the daily clinic. It does not take long to apply and does not require special skills or equipment