TY - JOUR A1 - Hansmann, P. A1 - Parragh, N. A1 - Toschi, A. A1 - Sangiovanni, G. A1 - Held, K. T1 - Importance of d-p Coulomb interaction for high T-C cuprates and other oxides JF - New Journal of Physics N2 - Current theoretical studies of electronic correlations in transition metal oxides typically only account for the local repulsion between d-electrons even if oxygen ligand p-states are an explicit part of the effective Hamiltonian. Interatomic interactions such as U-pd between d- and (ligand) p-electrons, as well as the local interaction between p-electrons, are neglected. Often, the relative d-p orbital splitting has to be adjusted 'ad hoc' on the basis of the experimental evidence. By applying the merger of local density approximation and dynamical mean field theory to the prototypical case of the three-band Emery dp model for the cuprates, we demonstrate that, without any 'ad hoc' adjustment of the orbital splitting, the charge transfer insulating state is stabilized by the interatomic interaction U-pd. Our study hence shows how to improve realistic material calculations that explicitly include the p-orbitals. KW - correlated electrons KW - dynamical mean field theory KW - transition metal oxides KW - fermions KW - superconductivity KW - energy bands KW - transition metals KW - correlated systems KW - mean-field theory KW - electronic-structure calculations KW - inplane spectral weight KW - Hubbard model KW - infinite dimensions Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-117165 SN - 1367-2630 VL - 16 IS - 33009 ER - TY - JOUR A1 - Schümann, Franziska Lea A1 - Groß, Elisabeth A1 - Bauer, Marcus A1 - Rohde, Christian A1 - Sandmann, Sarah A1 - Terziev, Denis A1 - Müller, Lutz P. A1 - Posern, Guido A1 - Wienke, Andreas A1 - Fend, Falko A1 - Hansmann, Martin-Leo A1 - Klapper, Wolfram A1 - Rosenwald, Andreas A1 - Stein, Harald A1 - Dugas, Martin A1 - Müller-Tidow, Carsten A1 - Wickenhauser, Claudia A1 - Binder, Mascha A1 - Weber, Thomas T1 - Divergent effects of EZH1 and EZH2 protein expression on the prognosis of patients with T-cell lymphomas JF - Biomedicines N2 - T-cell lymphomas are highly heterogeneous and their prognosis is poor under the currently available therapies. Enhancers of zeste homologue 1 and 2 (EZH1/2) are histone H3 lysine-27 trimethyltransferases (H3K27me3). Despite the rapid development of new drugs inhibiting EZH2 and/or EZH1, the molecular interplay of these proteins and the impact on disease progression and prognosis of patients with T-cell lymphomas remains insufficiently understood. In this study, EZH1/2 mutation status was evaluated in 33 monomorphic epitheliotropic intestinal T-cell lymphomas by next generation sequencing and EZH1/2 and H3K27me3 protein expression levels were detected by immunohistochemistry in 46 T-cell lymphomas. Correlations with clinicopathologic features were analyzed and survival curves generated. No EZH1 mutations and one (3%) EZH2 missense mutation were identified. In univariable analysis, high EZH1 expression was associated with an improved overall survival (OS) and progression-free survival (PFS) whereas high EZH2 and H3K27me3 expression were associated with poorer OS and PFS. Multivariable analysis revealed EZH1 (hazard ratio (HR) = 0.183; 95% confidence interval (CI): 0.044–0.767; p = 0.020;) and EZH2 (HR = 8.245; 95% CI: 1.898–35.826; p = 0.005) to be independent, divergent prognostic markers for OS. In conclusion, EZH1/2 protein expression had opposing effects on the prognosis of T-cell lymphoma patients. KW - T-cell non-Hodgkin's lymphomas KW - PTCL KW - epigenetics KW - EZH1 KW - EZH2 KW - H3K27me3 KW - immunohistochemistry KW - next generation sequencing Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-252155 SN - 2227-9059 VL - 9 IS - 12 ER - TY - JOUR A1 - Wagner, N. A1 - Crippa, L. A1 - Amaricci, A. A1 - Hansmann, P. A1 - Klett, M. A1 - König, E. J. A1 - Schäfer, T. A1 - Di Sante, D. A1 - Cano, J. A1 - Millis, A. J. A1 - Georges, A. A1 - Sangiovanni, G. T1 - Mott insulators with boundary zeros JF - Nature Communications N2 - The topological classification of electronic band structures is based on symmetry properties of Bloch eigenstates of single-particle Hamiltonians. In parallel, topological field theory has opened the doors to the formulation and characterization of non-trivial phases of matter driven by strong electron-electron interaction. Even though important examples of topological Mott insulators have been constructed, the relevance of the underlying non-interacting band topology to the physics of the Mott phase has remained unexplored. Here, we show that the momentum structure of the Green’s function zeros defining the “Luttinger surface" provides a topological characterization of the Mott phase related, in the simplest description, to the one of the single-particle electronic dispersion. Considerations on the zeros lead to the prediction of new phenomena: a topological Mott insulator with an inverted gap for the bulk zeros must possess gapless zeros at the boundary, which behave as a form of “topological antimatter” annihilating conventional edge states. Placing band and Mott topological insulators in contact produces distinctive observable signatures at the interface, revealing the otherwise spectroscopically elusive Green’s function zeros. KW - electronic properties and materials KW - topological insulators Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-358150 VL - 14 ER - TY - JOUR A1 - Hinderer, Svenja A1 - Shen, Nian A1 - Ringuette, Léa-Jeanne A1 - Hansmann, Jan A1 - Reinhardt, Dieter P A1 - Brucker, Sara Y A1 - Davis, Elaine C A1 - Schenke-Layland, Katja T1 - In vitro elastogenesis: instructing human vascular smooth muscle cells to generate an elastic fiber-containing extracellular matrix scaffold JF - Biomedical Materials N2 - Elastic fibers are essential for the proper function of organs including cardiovascular tissues such as heart valves and blood vessels. Although (tropo)elastin production in a tissue-engineered construct has previously been described, the assembly to functional elastic fibers in vitro using human cells has been highly challenging. In the present study, we seeded primary isolated human vascular smooth muscle cells (VSMCs) onto 3D electrospun scaffolds and exposed them to defined laminar shear stress using a customized bioreactor system. Increased elastin expression followed by elastin deposition onto the electrospun scaffolds, as well as on newly formed fibers, was observed after six days. Most interestingly, we identified the successful deposition of elastogenesis-associated proteins, including fibrillin-1 and -2, fibulin-4 and -5, fibronectin, elastin microfibril interface located protein 1 (EMILIN-1) and lysyl oxidase (LOX) within our engineered constructs. Ultrastructural analyses revealed a developing extracellular matrix (ECM) similar to native human fetal tissue, which is composed of collagens, microfibrils and elastin. To conclude, the combination of a novel dynamic flow bioreactor and an electrospun hybrid polymer scaffold allowed the production and assembly of an elastic fiber-containing ECM. KW - elastin KW - elastic fibers KW - electrospinning KW - tissue engineering KW - regenerative medicine KW - heart valve KW - cardiovascular Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-254074 VL - 10 IS - 3 ER -