The performance of battery electrode materials is strongly affected by inefficiencies in utilization kinetics and cycle life as well as size effects. Observations of phase transformations in these materials with high chemical and spatial resolution can elucidate the relationship between chemical processes and mechanical degradation. Soft X-ray ptychographic microscopy combined with X-ray absorp...

1. Sodium was injected into an identified snail neurone by passing current between two intracellular micro-electrodes, the membrane potential being recorded with a third micro-electrode.2. The injection of about 25 p-equiv Na, but not the injection of similar quantities of K or Li, caused a hyperpolarization of up to 20 mV. This response to Na injection was blocked by application of ouabain or ...

We analyzed the interaction between polyamines and the outer membrane of Escherichia coli cells using potentiometric measurements with Ca(2+), tetraphenylphosphonium (TPP(+)), and K(+) electrodes. The Ca(2+) electrode was used to examine the ability of the polyamines to release Ca(2+) from the outer membrane. The TPP(+) electrode was used to examine the ability to permeabilize the outer membran...

Highly sensitive, easy-to-fabricate, and low-cost pH sensors with small dimensions are required to monitor human bodily fluids, drinking water quality and chemical/biological processes. In this study, a low-temperature, solution-based process is developed to prepare palladium/palladium oxide (Pd/PdO) thin films for pH sensing. A precursor solution for Pd is spin coated onto pre-cleaned glass su...

To achieve high efficiency lithium ion batteries (LIBs), an effective active material is important. In this regard, monodisperse mesoporous titania beads (MMTBs) featuring well interconnected nanoparticles were synthesised, and their mesoporous properties were tuned to study how these affect the electrochemical performance in LIBs. Two pore diameters of 15 and 25 nm, three bead diameters of 360...

The equilibrium reduction potential of the 2[4Fe-4S] ferredoxin (Fd) isolated from four different bacterial strains was determined at a methyl viologen-modified gold electrode using square wave voltammetry. The observed reduction potential at pH 8 for Clostridium thermoaceticum Fd was -385 mV; Clostridium pasteurianum, -393 mV; Clostridium thermosaccharolyticum, -408 mV; and Chromatium vinosum,...

The production of pyocyanin from the opportunistic pathogen Pseudomonas aeruginosa was probed using a variety of miniaturized electrochemical systems. Goal 1 used disposable screen printed carbon electrodes to measure pyocyanin in medically relevant samples showing for the first time that pyocyanin can be detected at medically relevant concentrations (1-100 µM) without sample processing. Goal 2...

This paper presents the use of electrochemical impedance measurement on a cell chip to monitor cell growth as a consequence of treatment with potentially cytotoxic agents. The cell chip consists of an eight-well cell culture chamber incorporated with a three-electrode system on each well. The gold electrode for impedance measurements is fabricated by sputtering on polycarbonate film. Human hepa...

INTRODUCTION The present paper does not attempt to be exhaustive in listing all of the current trends in the polarography of organic compounds. Rather, an attempt has been made to focus attention on those trends, which seem of major importance for future studies in organic polarography, with particular reference to some of the unsolved problems which still confront us. Significant recent activi...

OBJECTIVE To monitor changes in cochlear function during cochlear implantation using electrocochleography (ECoG) and to correlate changes to postoperative hearing preservation. METHODS ECoG responses to acoustic stimuli of 250, 500, and 1000 Hz were recorded during cochlear implantation. The recording electrode was placed on the promontory and stabilized to fix the position during cochlear im...