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Heterotypic amyloid interactions between related protein sequences have been observed in functional and disease amyloids. While sequence homology seems to favour heterotypic amyloid interactions, we have no systematic understanding of the structural rules determining such interactions nor whether they inhibit or facilitate amyloid assembly. Using structure-based thermodynamic calculations and extensive experimental validation, we performed a comprehensive exploration of the defining role of sequence promiscuity in amyloid interactions. Using this knowledge, we demonstrate, using tau as a model system, that predicted cross-interactions driven by sequence homology indeed can modify nucleation, fibril morphology, kinetic assembly and cellular spreading of aggregates. We also find that these heterotypic amyloid interactions can result in the mis-localisation of brain-expressed protein sequences with prevalent activities in neurodegenerative disorders. Our findings suggest a structural mechanism by which the proteomic background can modulate the aggregation propensity of amyloidogenic proteins and discuss how such sequence-specific proteostatic perturbations could contribute to the selective cellular susceptibility of amyloid disease progression.

International audienceThis paper introduces a relevant concept of energy harvesting for passive UHF radio frequency identification (RFID) relying on the exploitation of the power carried by the third harmonic signal generated by the RFID chip. The idea consists on the use of the sole third harmonic energy to power up an associated sensor to the RFID tag. The proposed concept is first demonstrated in simulation thanks to an equivalent model for the RF front-end of a passive UHF RFID chip. Although the proposed model is simplified, it considers the generated nonlinear signals, allowing an efficient design of the rectifier circuit, which is responsible of harvesting the third harmonic power besides ensuring the activation of the RFID chip in order to communicate with the reader. The power driving between the RFID chip, third harmonic harvester, and antenna at the fundamental and third harmonic frequencies is achieved by designing a low-loss distributed three-port impedance matching network. Simulation results confirm the operation of the matching network and the exploitation of the third harmonic signal by analyzing the power at different nodes in the circuit. Measurement results validate the proposed nonlinear chip model. A prototype of the RFID tag harmonic-harvester produces 39 μW of dc power harvested from the harmonic signal, showing good agreement with the simulation results. Finally, a sensor application exploiting the harmonic harvested power to energize a commercial temperature sensor at a distance of 80 cm from the reader is demonstrated

This paper proposes a novel cooperative composite energy harvesting system that consists in the association of a traditional passive UHF Radio Frequency Identification (RFID) chip with an Electromagnetic Energy Harvesting Circuit (EEH-C). The objective is to exploit the i-v nonlinearity of the rectifier by applying a signal with time-varying envelope in order to improve the RF-to-dc conversion efficiency. Thanks to a multisource configuration, i.e. an RFID reader at 0.868 GHz and an external source at 2.45 GHz, the EEH-C is able to rectify the 3 rd harmonic product of the RFID chip, in addition to the 2.45 GHz signal, without compromising the RFID communication. Additionally, digitally modulated signals are used at 2.45 GHz to further enhance the harvesting efficiency of the EEH-C. From theory, simulations and measurement it is demonstrated that the exploitation of the three nonlinear effects of rectifying circuits, i.e., (i) impedance power dependency, (ii) harmonic signals production, and (iii) waveform dependency can greatly improve the conversion efficiency of the EEH-C.