19 research outputs found
Giant photo-effect in proton transport through graphene membranes
Graphene has recently been shown to be permeable to thermal protons, the
nuclei of hydrogen atoms, which sparked interest in its use as a
proton-conducting membrane in relevant technologies. However, the influence of
light on proton permeation remains unknown. Here we report that proton
transport through Pt-nanoparticle-decorated graphene can be enhanced strongly
by illuminating it with visible light. Using electrical measurements and mass
spectrometry, we find a photoresponsivity of 10^4 A W-1, which translates into
a gain of 10^4 protons per photon with response times in the microsecond range.
These characteristics are competitive with those of state-of-the-art
photodetectors that are based on electron transport using silicon and novel
two-dimensional materials. The photo-proton effect can be important for
graphene's envisaged use in fuel cells and hydrogen isotope separation. Our
observations can also be of interest for other applications such as
light-induced water splitting, photocatalysis and novel photodetectors
MR-Less Surface-Based Amyloid Assessment Based on C-11 PiB PET
Background: beta-amyloid (A beta) plaques in brain's grey matter (GM) are one of the pathological hallmarks of Alzheimer's disease (AD), and can be imaged in vivo using Positron Emission Tomography (PET) with C-11 or F-18 radiotracers. Estimating A beta burden in cortical GM has been shown to improve diagnosis and monitoring of AD. However, lacking structural information in PET images requires such assessments to be performed with anatomical MRI scans, which may not be available at different clinical settings or being contraindicated for particular reasons. This study aimed to develop an MR-less A beta imaging quantification method that requires only PET images for reliable A beta burden estimations