There is growing concern that nanoparticles (NPs) may accelerate amyloid protein aggregation and thus cause amyloid-related diseases. Here, the potential of silver and gold NPs is explored (diameter 20 nm) on the aggregation of the amyloid peptide sequences NNFGAIL from human islet amyloid polypeptide and the yeast prion protein sequence GNNQQNY, which are both the sequences of the full systems, which are able to aggregate into characteristic amyloid cross-beta sheet fi brillar structures. Here, it is shown that silver and gold NPs in physiological aqueous solution at ambient temperatures accelerate the aggregation kinetics of both peptides signifi cantly (in vitro). Scanning electron microscopy and X-ray diffraction provide solid evidence for a "structure-making" effect of the NPs. In particular, we are able to image the initial peptide corona and measure its structural reorganization in timeresolved kinetic experiments. After a conversion time Δ t , the coated NPs appear to act as templates or seeds for rapid fi brillation. Interestingly, crossfi brillation experiments with different peptide-coated NPs (pcNPs) reveal that they can effi ciently induce aggregation of similar peptides once the pcNPs are structurally converted. It is discussed that these structurally converted pcNPs may display similar kinetic features as toxic and aggregation inducing oligomers/protofi brils in normal amyloid aggregation, without being transient and very low-concentration species. Finally, we suggest and discuss a simple mechanistic picture with the biomolecule corona of NPs being central to the function of the coated NPs in amyloid fi brillation.

No abstract

Stable and high electrode performance is paired with low catalyst loading, achieved by using a novel electrode architecture. Finely dispersed, 2–3 nm Pt particles on CNTs are obtained via metal-organic chemical vapor deposition, forming an interconnected catalyst network on solid acid microparticles.

In the present article, electrodes containing a composite of platinum on top of a plasma-oxidized multi-layer graphene film are investigated as model electrodes that combine an exceptional high platinum utilization with high electrode stability. Graphene is thereby acting as a separator between the phosphate-based electrolyte and the platinum catalyst. Electrochemical impedance measurements in humidified hydrogen at 240 °C show area-normalized electrode resistance of 0.06 Ω·cm−2 for a platinum loading of ∼60 µgPt·cm−2, resulting in an outstanding mass normalized activity of almost 280 S·mgPt−1, exceeding even state-of-the-art electrodes. The presented platinum decorated graphene electrodes enable stable operation over 60 h with a non-optimized degradation rate of 0.15% h−1, whereas electrodes with a similar design but without the graphene as separator are prone to a very fast degradation. The presented results propose an efficient way to stabilize solid acid fuel cell electrodes and provide valuable insights about the degradation processes which are essential for further electrode optimization.

Abstract-It is a challenge for mobile robots to climb a vertical wall primarily due to requirements for reliable locomotion, high manoeuvrability, and robust and efficient attachment and detachment. Such robots have immense potential to automate tasks which are currently accomplished manually, offering an extra degree of human safety in a cost effective manner. In contrast to vacuum suction, magnetic adhesion, and dry techniques used existing wall climbing robots, Canterbury's research effort focuses on a novel approach which achieves attachment and detachment based on Bernoulli Effect. The adhesion force is achieved on a variety of surfaces, independent on the material of the wall and surface conditions. Such ubiquitous mobility with a force / weight ratio as high as 5 is nearly impossible to be achieved by other adhesion methods.Index Terms-Bernoulli Effect, wall climbing robot, attraction force, adhesion, attachment mechanism