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- ItemA new bifunctional hybrid nanostructure as an active platform for photothermal therapy and MR imaging(London : Nature Publishing Group, 2016) Khafaji, Mona; Vossoughi, Manouchehr; Hormozi-Nezhad, M. Reza; Dinarvand, Rassoul; Börrnert, Felix; Irajizad, AzamAs a bi-functional cancer treatment agent, a new hybrid nanostructure is presented which can be used for photothermal therapy by exposure to one order of magnitude lower laser powers compared to similar nanostructures in addition to substantial enhancment in magnetic resonance imaging (MRI) contrast. This gold-iron oxide hybrid nanostructure (GIHN) is synthesized by a cost-effective and high yield water-based approach. The GIHN is sheilded by PEG. Therefore, it shows high hemo and biocompatibility and more than six month stability. Alongside earlier nanostructures, the heat generation rate of GIHN is compareable with surfactnat-capped gold nanorods (GNRs). Two reasons are behind this enhancement: Firstly the distance between GNRs and SPIONs is adjusted in a way that the surface plasmon resonance of the new nanostructure is similar to bare GNRs and secondly the fraction of GNRs is raised in the hybrid nanostructure. GIHN is then applied as a photothermal agent using laser irradiation with power as low as 0.5 W.cm−2 and only 32% of human breast adenocarcinoma cells could survive. The GIHN also acts as a dose-dependent transvers relaxation time (T2) MRI contrast agent. The results show that the GINH can be considered as a good candidate for multimodal photothermal therapy and MRI.
- ItemEntwicklung eines Plasma-Emissionsdetektors für die Bestimmung von Schwermetall-Spezies für Anwendungen in der Umweltanalytik, Lebensmittel-Qualitätssicherung und Umweltmedizin : Schlussbericht ; (Bewilligungszeitraum: 01.02.2009 - 31.07.2012)(Greifswald : Leibniz-Institut für Plasmaforschung und Technologie, 2012) Wolfgang Buscher, Wolfgang Buscher; Ehlbeck, Jörg; Piechotta, Christian[no abstract available]
- ItemTIGeR - Tribologische Innovation mit Graphenen: Ansätze zur extremen Reibminderung : Abschlussbericht des BMBF Vorhabens ; Laufzeit des Vorhabens 01.08.2010 - 31.07.2012 ; ... wissenschaftliches Vorprojekt im WING - Programm(Hannover : Technische Informationsbibliothek (TIB), 2012) Bennewitz, Roland[no abstract available]
- ItemNesting-driven multipolar order in CeB6 from photoemission tomography(London : Nature Publishing Group, 2016) Koitzsch, A.; Heming, N.; Knupfer, M.; Büchner, B.; Portnichenko, P.Y.; Dukhnenko, A.V.; Shitsevalova, N.Y.; Filipov, V.B.; Lev, L.L.Some heavy fermion materials show so-called hidden-order phases which are invisible to many characterization techniques and whose microscopic origin remained controversial for decades. Among such hidden-order compounds, CeB6 is of model character due to its simple electronic configuration and crystal structure. Apart from more conventional antiferromagnetism, it shows an elusive phase at low temperatures, which is commonly associated with multipolar order. Here we show that this phase roots in a Fermi surface instability. This conclusion is based on a full 3D tomographic sampling of the electronic structure by angle-resolved photoemission and comparison with inelastic neutron scattering data. The hidden order is mediated by itinerant electrons. Our measurements will serve as a paradigm for the investigation of hidden-order phases in f-electron systems, but also generally for situations where the itinerant electrons drive orbital or spin order.
- ItemTheoretical approach to resonant inelastic X-ray scattering in iron-based superconductors at the energy scale of the superconducting gap(London : Nature Publishing Group, 2016) Marra, Pasquale; van den Brink, Jeroen; Sykora, SteffenWe develop a phenomenological theory to predict the characteristic features of the momentum-dependent scattering amplitude in resonant inelastic x-ray scattering (RIXS) at the energy scale of the superconducting gap in iron-based super-conductors. Taking into account all relevant orbital states as well as their specific content along the Fermi surface we evaluate the charge and spin dynamical structure factors for the compounds LaOFeAs and LiFeAs, based on tight-binding models which are fully consistent with recent angle-resolved photoemission spectroscopy (ARPES) data. We find a characteristic intensity redistribution between charge and spin dynamical structure factors which discriminates between sign-reversing and sign-preserving quasiparticle excitations. Consequently, our results show that RIXS spectra can distinguish between s± and s++ wave gap functions in the singlet pairing case. In addition, we find that an analogous intensity redistribution at small momenta can reveal the presence of a chiral p-wave triplet pairing.
- ItemSO/PHI - ISS Image Stabilization System for the Solar Orbiter Polarimetric and Helioseismic Imager : Schlussbericht zum Vorhaben "Entwicklung der Bildstabilisierungseinheit ISS für das Instrument PHI auf Solar Orbiter" ; Förderzeitraum: 01.07.2012-31.12.2016(Hannover : Technische Informationsbibliothek (TIB), 2017) Schmidt, Wolfgang; Volkmer, Reiner[no abstract available]
- ItemMicrostructure evolution during annealing of an SPD- processed supersaturated Cu – 3 at.% Ag alloy(Bristol : IOP Publishing, 2014) Gubicza, J.; Hegedűs, Z.; Lábár, J.L.; Sarma, V.S.; Kauffmann, A.; Freudenberger, J.Supersaturated Cu-3 at.% Ag alloy was processed by rolling at liquid nitrogen temperature and subsequent annealing at 623 K up to 20 min. It was found that after annealing, an inhomogeneous solute atom distribution developed, since the Ag particles with small size and/or large specific interfacial energy were dissolved due to the Gibbs-Thomson effect. In the region where the solute concentration increased, a high dislocation density was retained in the Cu matrix even after annealing, while in the region where the Ag solute content did not increase, the dislocation density decreased by more than one order of magnitude. Therefore, in the cryorolled and annealed samples, heterogeneous microstructures were developed where both the dislocation density and the solute concentration varied considerably.
- ItemVerbundprojekt 1:Technologiebaukasten, Teilprojekt 1.5 - Institut für Photonische Technologien e.V. (IPHT): Methodenentwicklung für Prozessdiagnostik und prozessvorbereitende Maßnahmen für ausgewählte Beschichtungsverfahren : Wachstumskern "J-1013" - Surface Technologies Net ; Abschlussbericht(Hannover : Technische Informationsbibliothek (TIB), 2014) Paa, Wolfgang; Burkert, Alfons[no abstract available]
- ItemUnderstanding the catalyst-free transformation of amorphous carbon into graphene by current-induced annealing(London : Nature Publishing Group, 2013) Barreiro, Amelia; Börrnert, Felix; Avdoshenko, Stanislav M.; Rellinghaus, Bernd; Cuniberti, Gianaurelio; Rümmeli, Mark H.; Vandersypen, Lieven M.K.We shed light on the catalyst-free growth of graphene from amorphous carbon (a–C) by current-induced annealing by witnessing the mechanism both with in-situ transmission electron microscopy and with molecular dynamics simulations. Both in experiment and in simulation, we observe that small a–C clusters on top of a graphene substrate rearrange and crystallize into graphene patches. The process is aided by the high temperatures involved and by the van der Waals interactions with the substrate. Furthermore, in the presence of a–C, graphene can grow from the borders of holes and form a seamless graphene sheet, a novel finding that has not been reported before and that is reproduced by the simulations as well. These findings open up new avenues for bottom-up engineering of graphene-based devices.
- ItemVerbundprojekt 5: Herstellung, Bearbeitung und Charakterisierung von AlN-Substratkristallen, Teilprojekt 5.1: Sublimationszüchtung von AlN-Einkristallen im Wachstumskern Berlin WideBaSe : Schlußbericht ; Projektlaufzeit: 01.07.2010 bis 31.06.2013(Hannover : Technische Informationsbibliothek (TIB), 2013) Wollweber, Jürgen[no abstract available]