Rozhkova E.A.,Argonne National Laboratory
Advanced Materials | Year: 2011
This article reports on recent progress in the development of advanced nanoscale photoreactive, magnetic and multifunctional materials applicable to brain cancer diagnostics, imaging, and therapy, with an emphasis on the latest contributions and the novelty of the approach, along with the most promising emergent trends. This article reports on recent progress in the development of advanced nanoscale photoreactive, magnetic and multifunctional materials applicable to brain cancer diagnostics, imaging, and therapy, with an emphasis on the latest contributions and the novelty of the approach, along with the most promising emergent trends. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Lin X.-M.,Argonne National Laboratory
Nano Letters | Year: 2010
Critical photonic, electronic, and magnetic applications of two-dimensional nanocrystal superlattices often require nanostructures in perfect single-crystal phases with long-range order and limited defects. Here we discovered a crystalline phase with quasi long range positional order for two-dimensional nanocrystal superlattice domains self-assembled at the liquid-air interface during droplet evaporation, using in situ time-resolved X-ray scattering along with rigorous theories on two dimensional crystal structures. Surprisingly, it was observed that drying these superlattice domains preserved only an orientational order but not a longrange positional order, also supported by quantitative analysis of transmission electron microscopy images. © 2010 American Chemical Society.
Kuzmenko I.,Argonne National Laboratory
Physical Review Letters | Year: 2010
We report a structural study of cholesterol-DPPC (1,2-dipalmitoyl-sn- glycero-3-phophocholine) monolayers using x-ray reflectivity and grazing incidence x-ray diffraction. Reflectivity reveals that the vertical position of cholesterol relative to phospholipids strongly depends on its mole fraction (χCHOL). Moreover, we find that at a broad range of χCHOL cholesterol and DPPC form alloylike mixed domains of short-range order and the same stoichiometry as that of the film. Based on the data presented, we propose a new model of cholesterol-phospholipid organization in mixed monolayers. © 2010 The American Physical Society.
Ilavsky J.,Argonne National Laboratory
Journal of Applied Crystallography | Year: 2012
Nika is an Igor Pro-based package for correction, calibration and reduction of two-dimensional area-detector data into one-dimensional data (lineouts). It is free (although the user needs a paid license for Igor Pro), open source and highly flexible. While typically used for small-angle X-ray scattering (SAXS) data, it can also be used for grazing-incidence SAXS data, wide-angle diffraction data and even small-angle neutron scattering data. It has been widely available to the user community since about 2005, and it is currently used at the SAXS instruments of selected large-scale facilities as their main data reduction package. It is, however, also suitable for desktop instruments when the manufacturers software is not available or appropriate. Since it is distributed as source code, it can be scrutinized, verified and modified by users to suit their needs. © 2012 International Union of Crystallography Printed in Singapore-all rights reserved.
Dauter Z.,Argonne National Laboratory
Acta Crystallographica Section D: Biological Crystallography | Year: 2013
There are currently no rules for a unified, standard way of placing macromolecular structures in the crystal lattice. An analysis of all possible symmetry-equivalent representations of molecular structures in various space groups leads to the concept of the anti-Cheshire symmetry and suggests that the center of a unique structural motif can always be placed within the selected asymmetric unit of the anti-Cheshire cell. The placement of structures according to this suggestion will ensure uniformity of presentation of all structurally equivalent Protein Data Bank models and will therefore diminish the possibility of confusing less crystallographically knowledgeable users of the PDB. The anti-Cheshire cells and their asymmetric units are defined and tabulated for all 65 space groups relevant to macromolecular crystallography that exhibit only rotational symmetry operations. © 2013 International Union of Crystallography Printed in Singapore - all rights reserved.