Stochastic Kinetic Study of Protein Aggregation and Molecular Crowding Effects of Ab40 and Ab42

Two isoforms of beta amyloid peptides, Ab40 and Ab42, differ from each other only in the last two amino acids, IA, at the end of Ab42. They, however, differ significantly in their ability in inducing Alzheimer's disease (AD). The rate curves of fibril growth of Ab40 and Ab42 and the effects of molecular crowding have been measured in in vitro experiments. These experimental curves, on the other hand, have been fitted in terms of rate constants for elementary reaction steps using rate equation approaches. Several sets of such rate parameters have been reported in the literature. Employing a recently developed stochastic kinetic method, implemented in a browser-based simulator, popsim, we study to reveal the differences in the kinetic behaviors implied by these sets of rate parameters. In particular, the stochastic method is used to distinguish the kinetic behaviors between Ab40 and Ab42 isoforms. As a result, we make general comments on the usefulness of these sets of rate parameters.Comment: To appear in the Journal of the Chinese Chemical Societ

Heat recovery mechanism in the excitation of radiative polaritons by broadband infrared radiation in thin oxide films

This work probes radiative polaritons in thin oxide layers as a mean to capture and absorb broadband infrared radiation and transform it into heat. A heat recovery mechanism, based on the Seebeck effect, is used as the tool of the investigation. Heat production challenges the current understanding which views the excitation of radiative polaritons as only accompanied by the emission of electromagnetic radiation. The heat recovery mechanism presented here can inspire the design of infrared energy harvesting devices, similar to photovoltaic cells, and other devices to convert energy from a wide range of the electromagnetic radiation spectrum using thermoelectric power generators