Surfactant-directed synthesis of branched bismuth telluride/sulfide core/shell nanorods.

Branched core/shell bismuth telluride/bismuth sulfide nanorod heterostructures are prepared by using a biomimetic surfactant, L-glutathionic acid. Trigonal nanocrystals of bismuth telluride are encapsulated by nanoscopic shells of orthorhombic bismuth sulfide. Crystallographic twinning causes shell branching.

Multiresolution analysis of event-related potentials by wavelet decomposition.

Wavelet analysis is presented as a new tool for analyzing event-related potentials (ERPs). The wavelet transform expands ERPs into a time-scale representation, which allows the analyst to zoom in on the small scale, fine structure details of an ERP or zoom out to examine the large scale, global waveshape. The time-scale representation is closely related to the more familiar time-frequency representation used in spectrograms of time-varying signals.

Epicardial electrical activation analyzed via frequency-wavenumber spectrum estimation for the characterization of arrhythmiagenic states.

The application of a new signal processing methodology to the analysis of epicardial array ECG signals is presented as an alternative to isopotential or isochrones mapping by the use of a zero-delay wavenumber spectrum (ZDWS) estimation technique. The methodology "explains" the array data as the sum of modulated wideband (non-sinusoidal) propagating waves projected onto the array plane and provides an accurate estimate of their number and bearing. The slowness distribution of each of the waves is then obtained by estimating their temporal spectrum.

A new parametric frequency-wavenumber spectrum estimation algorithm and its application to the analysis of 3-dimensional epicardial ECG signals.

This paper presents a 3-dimensional (3-D) frequency-wavenumber spectrum estimation (FWSE) approach to the analysis of ECG signals. This approach treats the data as 'wavefronts plus noise' and provides a means of estimating key parameters associated with propagating wavefronts. A high resolution technique based on minimum variance representations of 3-D data fields (3-D CLS technique) is employed to obtain the FWSE.