TY - JOUR A1 - Bastian, Philipp U. A1 - Robel, Nathalie A1 - Schmidt, Peter A1 - Schrumpf, Tim A1 - Günter, Christina A1 - Roddatis, Vladimir A1 - Kumke, Michael U. T1 - Resonance energy transfer to track the motion of lanthanide ions BT - what drives the intermixing in core-shell upconverting nanoparticles? JF - Biosensors : open access journal N2 - The imagination of clearly separated core-shell structures is already outdated by the fact, that the nanoparticle core-shell structures remain in terms of efficiency behind their respective bulk material due to intermixing between core and shell dopant ions. In order to optimize the photoluminescence of core-shell UCNP the intermixing should be as small as possible and therefore, key parameters of this process need to be identified. In the present work the Ln(III) ion migration in the host lattices NaYF4 and NaGdF4 was monitored. These investigations have been performed by laser spectroscopy with help of lanthanide resonance energy transfer (LRET) between Eu(III) as donor and Pr(III) or Nd(III) as acceptor. The LRET is evaluated based on the Forster theory. The findings corroborate the literature and point out the migration of ions in the host lattices. Based on the introduced LRET model, the acceptor concentration in the surrounding of one donor depends clearly on the design of the applied core-shell-shell nanoparticles. In general, thinner intermediate insulating shells lead to higher acceptor concentration, stronger quenching of the Eu(III) donor and subsequently stronger sensitization of the Pr(III) or the Nd(III) acceptors. The choice of the host lattice as well as of the synthesis temperature are parameters to be considered for the intermixing process. KW - upconversion nanoparticles KW - lanthanoid migration KW - lanthanides KW - core-shell KW - energy transfer Y1 - 2021 U6 - https://doi.org/10.3390/bios11120515 SN - 2079-6374 VL - 11 IS - 12 PB - MDPI CY - Basel ER - TY - JOUR A1 - Wessig, Pablo A1 - Badetko, Dominik A1 - Czarnecki, Maciej A1 - Wichterich, Lukas A1 - Schmidt, Peter A1 - Brudy, Cosima A1 - Sperlich, Eric A1 - Kelling, Alexandra T1 - Studies toward the total synthesis of arylnaphthalene lignans via a Photo-Dehydro-Diels-Alder (PDDA) reaction JF - The journal of organic chemistry N2 - An efficient method for the preparation of arylnaphthalene lignans (ANLs) was developed, which is based on thePhoto-Dehydro-DIELS-ALDER(PDDA) reaction. While intermolecular PDDA reactions turned out to be inefficient, theintramolecular variant using suberic acid as tether linking two aryl propiolic esters smoothly provided naphthalenophanes. Theirradiations were performed with a previously developed annular continuous-flow reactor and UVB lamps. In this way, the naturalproducts Alashinol D, Taiwanin C, and an unnamed ANL could be prepared. Y1 - 2022 U6 - https://doi.org/10.1021/acs.joc.2c00195 SN - 0022-3263 SN - 1520-6904 VL - 87 IS - 9 SP - 5904 EP - 5915 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Schmidt, Peter T1 - Market failure vs. system failure as a rationale for economic policy? BT - A critique from an evolutionary perspective JF - Journal of Evolutionary Economics N2 - This paper reconsiders the explanation of economic policy from an evolutionary economics perspective. It contrasts the neoclassical equilibrium notions of market and government failure with the dominant evolutionary neo-Schumpeterian and Austrian-Hayekian perceptions. Based on this comparison, the paper criticizes the fact that neoclassical reasoning still prevails in non-equilibrium evolutionary economics when economic policy issues are examined. This is more than surprising, since proponents of evolutionary economics usually view their approach as incompatible with its neoclassical counterpart. In addition, it is shown that this "fallacy of failure thinking" even finds its continuation in the alternative concept of "system failure" with which some evolutionary economists try to explain and legitimate policy interventions in local, regional or national innovation systems. The paper argues that in order to prevent the otherwise fruitful and more realistic evolutionary approach from undermining its own criticism of neoclassical economics and to create a consistent as well as objective evolutionary policy framework, it is necessary to eliminate the equilibrium spirit. Finally, the paper delivers an alternative evolutionary explanation of economic policy which is able to overcome the theory-immanent contradiction of the hitherto evolutionary view on this subject. KW - Market failure KW - System failure KW - Economic policy KW - Policy advice KW - Evolutionary economics KW - Non-equilibrium economics Y1 - 2018 U6 - https://doi.org/10.1007/s00191-018-0564-6 SN - 0936-9937 SN - 1432-1386 VL - 28 IS - 4 SP - 785 EP - 803 PB - Springer CY - New York ER -