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Enschede, Netherlands

Stockl M.T.,MESA Institute for Nanotechnology
Molecular neurobiology | Year: 2013

In many human diseases, oligomeric species of amyloid proteins may play a pivotal role in cytotoxicity. Many lines of evidence indicate that permeabilization of cellular membranes by amyloid oligomers may be the key factor in disrupting cellular homeostasis. However, the exact mechanisms by which the membrane integrity is impaired remain elusive. One prevailing hypothesis, the so-called amyloid pore hypothesis, assumes that annular oligomeric species embed into lipid bilayers forming transbilayer protein channels. Alternatively, an increased membrane permeability could be caused by thinning of the hydrophobic core of the lipid bilayer due to the incorporation of the oligomers between the tightly packed lipids, which would facilitate the transport of small molecules across the membrane. In this review, we briefly recapitulate our findings on the structure of α-synuclein oligomers and the factors influencing their interaction with lipid bilayers. Our results, combined with work from other groups, suggest that α-synuclein oligomers do not necessarily form pore-like structures. The emerging consensus is that local structural rearrangements of the protein lead to insertion of specific regions into the hydrophobic core of the lipid bilayer, thereby disrupting the lipid packing. Source

Zandvliet H.J.W.,MESA Institute for Nanotechnology
Nano Today | Year: 2014

In the past decade a new exciting class of materials has been developed, which is not three-dimensional, but only two-dimensional in nature. Graphene is by far the most famous example of this new class of materials. Graphene exhibits a wealth of exotic and intriguing properties, which has resulted in a myriad of scientific breakthroughs. However, graphene also suffers from a severe drawback: it is gapless, implying that a graphene based field-effect transistor is not within reach. Silicene, the silicon analog of graphene, is in many aspects very similar to graphene, but in contrast to the planar graphene lattice, the silicene lattice is slightly buckled and composed of two vertically displaced sub-lattices. By breaking the sub-lattice symmetry a band gap can be opened, which would in principle allow the realization of a silicene field-effect transistor. This piece introduces the various band engineering options for silicene as well as additional hurdles that will need to be overcome before the door can be opened to a silicene transistor. © 2014 Elsevier Ltd. All rights reserved. Source

Controlled in-plane rotation of the magnetic easy axis in manganite heterostructures by tailoring the interface oxygen network could allow the development of correlated oxide-based magnetic tunnelling junctions with non-collinear magnetization, with possible practical applications as miniaturized high-switching-speed magnetic random access memory (MRAM) devices. Here, we demonstrate how to manipulate magnetic and electronic anisotropic properties in manganite heterostructures by engineering the oxygen network on the unit-cell level. The strong oxygen octahedral coupling is found to transfer the octahedral rotation, present in the NdGaO3 (NGO) substrate, to the La2/3Sr1/3MnO3 (LSMO) film in the interface region. This causes an unexpected realignment of the magnetic easy axis along the short axis of the LSMO unit cell as well as the presence of a giant anisotropic transport in these ultrathin LSMO films. As a result we possess control of the lateral magnetic and electronic anisotropies by atomic-scale design of the oxygen octahedral rotation. © 2016 Nature Publishing Group Source

Tormo P.,Aalto University | Barnes W.L.,University of Exeter | Barnes W.L.,MESA Institute for Nanotechnology
Reports on Progress in Physics | Year: 2015

In this review we look at the concepts and state-of-the-art concerning the strong coupling of surface plasmon-polariton modes to states associated with quantum emitters such as excitons in J-aggregates, dye molecules and quantum dots. We explore the phenomenon of strong coupling with reference to a number of examples involving electromagnetic fields and matter. We then provide a concise description of the relevant background physics of surface plasmon polaritons. An extensive overview of the historical background and a detailed discussion of more recent relevant experimental advances concerning strong coupling between surface plasmon polaritons and quantum emitters is then presented. Three conceptual frameworks are then discussed and compared in depth: classical, semi-classical and fully quantum mechanical; these theoretical frameworks will have relevance to strong coupling beyond that involving surface plasmon polaritons. We conclude our review with a perspective on the future of this rapidly emerging field, one we are sure will grow to encompass more intriguing physics and will develop in scope to be of relevance to other areas of science. © 2015 IOP Publishing Ltd. Source

Versluis M.,MESA Institute for Nanotechnology
Experiments in Fluids | Year: 2013

High-speed imaging is in popular demand for a broad range of experiments in fluids. It allows for a detailed visualization of the event under study by acquiring a series of image frames captured at high temporal and spatial resolution. This review covers high-speed imaging basics, by defining criteria for high-speed imaging experiments in fluids and to give rule of thumbs for a series of cases. It also considers stroboscopic imaging, triggering and illumination, and scaling issues. It provides guidelines for testing and calibration. Ultra-high-speed imaging at frame rates exceeding 1 million frames per second is reviewed, and the combination of conventional experiments in fluid techniques with high-speed imaging techniques is discussed. The review is concluded with a high-speed imaging chart, which summarizes criteria for temporal scale and spatial scale and which facilitates the selection of a high-speed imaging system for the application. © 2013 Springer-Verlag Berlin Heidelberg. Source

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