Aperiodic composite crystals present long-range order without translational symmetry. These materials may be described as the intersection in three dimensions of a crystal which is periodic in a higher-dimensional space. In such materials, symmetry breaking must be described as structural changes within these crystallographic superspaces. The increase in the number of superspace groups with the increase in the dimension of the superspace allows many more structural solutions. This is illustrated in n-nonadecane-urea, revealing a fifth higher-dimensional phase at low temperature.
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http://dx.doi.org/10.1107/S2052520615005442 | DOI Listing |
Polymers (Basel)
January 2025
Department of Chemistry and Pharmacy, Interdisciplinary Center for Molecular Materials, Friedrich-Alexander Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany.
pH-responsive polyamidoamine (PAMAM) dendrimers are used as well-defined building blocks to design light-switchable nano-assemblies in solution. The complex interplay between the photoresponsive di-anionic azo dye Acid Yellow 38 (AY38) and the cationic PAMAM dendrimers of different generations is presented in this study. Electrostatic self-assembly involving secondary dipole-dipole interactions provides well-defined assemblies within a broad size range (10 nm-1 μm) with various shapes.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Institut Laue-Langevin (ILL), 71 Avenue des Martyrs, 38042 Grenoble Cedex 9, France.
Intense sources of very cold neutrons (VCNs) would be beneficial for various neutron scattering techniques and low-energy particle physics experiments. Binary clathrate hydrates hosting deuterated tetrahydrofuran (THF-d) and dioxygen show promise as potential moderators for such sources due to a rich spectrum of localized low-energy excitations of the encaged guest molecules. In this article, we present a reliable manufacturing technique for such hydrates.
View Article and Find Full Text PDFJ Colloid Interface Sci
April 2025
Institute of Physical and Theoretical Chemistry, University of Regensburg D-93053 Regensburg, Germany. Electronic address:
Hypothesis: Due to its huge polar headgroup, octaoxyethylene octyl ether carboxylic acid (CECHCOOH = Akypo LF2™) is supposed not to be able to change its curvature sufficiently to form bicontinuous microemulsions. Instead, upon adding an oil to the binary water - surfactant system, excess oil could be squeezed out or a biliquid foam could form.
Experiments: An auto-dilution setup was used to record small-angle X-ray scattering data along six dilution lines in the newly established phase diagram of the ternary system 2-ethylhexanol - CECHCOOH - water.
Appl Radiat Isot
March 2025
Instituto de Física Corpuscular (CSIC-Universidad de Valencia), Valencia, Spain.
This paper explores the adaptation and application of i-TED Compton imagers for real-time dosimetry in Boron Neutron Capture Therapy (BNCT). The i-TED array, previously utilized in nuclear astrophysics experiments at CERN, is being optimized for detecting and imaging 478 keV gamma-rays, critical for accurate BNCT dosimetry. Detailed Monte Carlo simulations were used to optimize the i-TED detector configuration and enhance its performance in the challenging radiation environment typical of BNCT.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom. Electronic address:
Understanding the architecture and mechanism of assembly of polyelectrolyte-nucleic acid complexes is critical to the rational design of their performance for gene delivery. Surface-initiated polymer brushes were recently found to be particularly effective at delivering oligonucleotides and maintaining high knock down efficiencies for prolonged periods of time, in highly proliferative cells. However, what distinguishes their binding capacity for oligonucleotides from that of larger therapeutic macromolecules remains unknown.
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