Biomedical subjects

Christopher J Rozell

Publications and source records attributed to Christopher J Rozell.

2 recordsLinked to original sources

PubMed2006

All-optical nanoscale pH meter.

We show that an Au nanoshell with a pH-sensitive molecular adsorbate functions as a standalone, all-optical nanoscale pH meter that monitors its local environment through the pH-dependent surface-enhanced Raman scattering (SERS) spectra of the adsorbate molecules. Moreover, we also show how the performance of such a functional nanodevice can be assessed quantitatively. The complex spectral output is reduced to a simple device characteristic by application of a locally linear manifold approximation algorithm. The average accuracy of the nano-"meter" was found to be +/-0.10 pH units across its operating range.

Equipment Design↗

PubMed2004

Measuring information transfer in the spike generator of crayfish sustaining fibers.

We present a method based on information-theoretic distances for measuring the information transfer efficiency of voltage to impulse encoders. In response to light pulses, we simultaneously recorded the EPSP and spiking output of crayfish sustaining fibers. To measure the distance between analog EPSP responses, we developed a membrane noise model that accurately captures stimulus-induced nonstationarities. By comparing the EPSP and spike responses, we found encoding efficiencies on the order of 10(-4), with interesting dynamics occurring during initial transients. A simple analog to point-process converter predicted the small information transfer efficiencies and dynamic properties we measured.

Action Potentials↗