Enhancing weak signal transmission through a feedforward network

The ability to transmit and amplify weak signals is fundamental to signal processing of artificial devices in engineering. Using a multilayer feedforward network of coupled double-well oscillators as well as Fitzhugh-Nagumo oscillators, we here investigate the conditions under which a weak signal received by the first layer can be transmitted through the network with or without amplitude attenuation. We find that the coupling strength and the nodes' states of the first layer act as two-state switches, which determine whether the transmission is significantly enhanced or exponentially decreased. We hope this finding is useful for designing artificial signal amplifiers.

EVALUATION OF THE POTENTIALITIES OF A CARBON NANOTUBES/SILICONE RUBBER COMPOSITE ELECTRODE IN THE DETERMINATION OF HYDROCHLOROTHIAZIDE

A multiwall carbon nanotube/silicone rubber (MWCNT/SR) composite electrode has been used for the determination of hydrochlorothiazide (HCTZ) in pharmaceutical formulations by differential pulse voltammetry (DPV). The electro-oxidation process was evaluated by cyclic voltammetry, from which it was observed that HCTZ presents an irreversible oxidation peak at 0.82 V vs. saturated calomel electrode (SCE) in the potential range from 0.5 to 1.1 V, in Britton-Robinson buffer pH 7.0 at MWCNT/SR. HCTZ was determined by DPV using a MWCNT/SR 70% (MWCNT, m/m) composite electrode after the optimization of the experimental parameters. The linear range was from 5.0 to 70.0 mu mol L-1, with a limit of detection (LOD) of 2.6 mu mol L-1. The HCTZ was determined in pharmaceutical formulations using the proposed composite electrode and the results agreed with those from the official high performance liquid chromatography (HPLC) method within 95% confidence level, according to the t-Student test.

Elaboração de diagnósticos e intervenções à luz de diferentes sistemas de classificações de enfermagem

Este estudo faz uma análise sobre o uso de diferentes sistemas de classificação e o atendimento aos padrões estabelecidos pela ISO 18.104:2003 a partir de uma situação clínica fictícia. Foram elaborados diagnósticos e intervenções de enfermagem utilizando a NANDA-I, NIC e CIPE®, e analisou-se a correspondência terminológica destes sistemas de classificação ao modelo proposto pela norma ISO 18.104:2003. Para a construção de diagnósticos de enfermagem, a NANDA-I e a CIPE® adequando-se à norma ISO 18.104:2003. Para a construção das intervenções de enfermagem, a CIPE® atende ao modelo de referência terminológica proposto pela ISO 18104:2003. Por sua vez, a NIC não propõe um modelo de referência terminológica combinatória. A unificação das terminologias de enfermagem depende da revisão, padronização e teste dessas classificações para o estabelecimento de uma linguagem comum e sólida da profissão.