Core-Shell Structured Fluorescent Protein Nanoparticles: New Paradigm Toward Zero-Thermal-Quenching in High-Power Biohybrid Light-Emitting Diodes.

Stable and efficient high-power biohybrid light-emitting diodes (Bio-HLEDs) using fluorescent proteins (FPs) in photon downconverting filters have not been achieved yet, reaching best efficiencies of 130 lm W-1 stable for >5 h. This is related to the rise of the device temperature (70-80 °C) caused by FP-motion and quick heat-transmission in water-based filters, they lead to a strong thermal emission quenching followed by the quick chromophore deactivation via photoinduced H-transfer. To tackle both issues at once, this work shows an elegant concept of a new FP-based nanoparticle, in which the FP core is shielded by a SiO2 -shell (FP@SiO2 ) with no loss of the photoluminescence figures-of-merit over years in foreign environments: dry powder at 25 °C (ambient) or constant 50 °C, as well as suspensions in organic solvents. This enables the preparation of water-free photon downconverting coatings with FP@SiO2 , realizing on-chip high-power Bio-HLEDs with 100 lm W-1 stable for >120 h. Both thermal emission quenching and H-transfer deactivation are suppressed, since the device temperature holds <40 °C and remote high-power Bio-HLEDs exhibit final stabilities of 130 days compared to reference devices with water-based FP@SiO2 (83 days) and FP-polymer coatings (>100 h). Hence, FP@SiO2 is a new paradigm toward water-free zero-thermal-quenching biophosphors for first-class high-power Bio-HLEDs.

Novel presenilin 1 mutation (Ile408Thr) in an Italian family with late-onset Alzheimer's disease.

Alzheimer's disease (AD) is a neurodegenerative disease affecting over 20 million people worldwide, mainly adult subjects in advanced age. Over 240 different fully penetrant autosomal dominant mutations in 532 families around the world have been described in three genes [i.e., amyloid precursor protein (APP), and presenilins (PSEN1 and PSEN2)] causing 50% of all Familial AD. We report a new mutation (p.Ile408Thr, c. 1223T>C) in the PSEN1 gene in one autosomal dominant Late Onset AD patient. The genetic variation occurred in a conserved domain of the protein and was present in the proband and in the younger sister who is likely to be prodromal AD. Thus, we suggest that this variant will have probably a pathogenic effect, hypothesizing a possible key role of this new mutation in the pathogenesis of Alzheimer's disease for this family.