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Full-Text Articles in Physical Sciences and Mathematics
Making Sense Of Nanocrystal Lattice Fringes, Phil Fraundorf, Wentao Qin, Peter Moeck, Eric Mandell
Making Sense Of Nanocrystal Lattice Fringes, Phil Fraundorf, Wentao Qin, Peter Moeck, Eric Mandell
Physics Faculty Works
The orientation dependence of thin-crystal lattice fringes can be gracefully quantified using fringe-visibility maps, a direct-space analog of Kikuchi maps [Nishikawa and Kikuchi, Nature (London) 121, 1019 (1928)]. As in navigation of reciprocal space with the aid of Kikuchi lines, fringe-visibility maps facilitate acquisition of crystallographic information from lattice images. In particular, these maps can help researchers to determine the three-dimensional lattice of individual nanocrystals, to “fringe-fingerprint” collections of randomly oriented particles, and to measure local specimen thickness with only a modest tilt. Since the number of fringes in an image increases with maximum spatial-frequency squared, these strategies (with help …
Amyloid-Β Protofibrils Differ From Amyloid-Β Aggregates Induced In Dilute Hexafluoroisopropanol In Stability And Morphology, Michael Nichols, Melissa Moss, Dana Reed, Stephanie Cratic-Mcdaniel, Jan Hoh, Terrone Rosenberry
Amyloid-Β Protofibrils Differ From Amyloid-Β Aggregates Induced In Dilute Hexafluoroisopropanol In Stability And Morphology, Michael Nichols, Melissa Moss, Dana Reed, Stephanie Cratic-Mcdaniel, Jan Hoh, Terrone Rosenberry
Chemistry & Biochemistry Faculty Works
The brains of Alzheimer’s disease (AD) patients contain large numbers of amyloid plaques that are rich in fibrils composed of 40- and 42-residue amyloid-β (Aβ) peptides. Several lines of evidence indicate that fibrillar Aβ and especially soluble Aβ aggregates are important in the etiology of AD. Recent reports also stress that amyloid aggregates are polymorphic and that a single polypeptide can fold into multiple amyloid conformations. Here we demonstrate that Aβ-(1–40) can form soluble aggregates with predominant β-structures that differ in stability and morphology. One class of aggregates involved soluble Aβ protofibrils, prepared by vigorous overnight agitation of monomeric Aβ-(1–40) …
Optical Spectroscopy Of The Surface Population Of The Ρ Ophiuchi Molecular Cloud: The First Wave Of Star Formation, Bruce Wilking, Michael Meyer, John Robinson, Thomas Greene
Optical Spectroscopy Of The Surface Population Of The Ρ Ophiuchi Molecular Cloud: The First Wave Of Star Formation, Bruce Wilking, Michael Meyer, John Robinson, Thomas Greene
Physics Faculty Works
We present the results of optical spectroscopy of 139 stars obtained with the Hydra multiobject spectrograph. The objects extend over a 1.3 deg2 area surrounding the main cloud of the ρ Oph complex. The objects were selected from narrowband images to have Hα in emission. Using the presence of strong Hα emission, lithium absorption, location in the Hertzsprung-Russell diagram, or previously reported X-ray emission, we were able to identify 88 objects as young stars associated with the cloud. Strong Hα emission was confirmed in 39 objects with line widths consistent with their origin in magnetospheric accretion columns. Two of the …