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4. Highly dispersive magnons with spin-gap like features in the frustrated ferromagnetic S=1/2 chain compound Ca2Y2Cu5O10 detected by inelastic neutron scattering

Author

Matsuda, M., Ma, J., Garlea, V. O., Ito, T., Yamaguchi, H., Oka, K., Drechsler, S. -L., Yadav, R., Hozoi, L., Rosner, H., Schumann, R., Kuzian, R. O., and Nishimoto, S.

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

We report inelastic neutron scattering experiments in Ca2Y2Cu5O10 and map out the full one magnon dispersion which extends up to a record value of 53 meV for frustrated ferromagnetic (FM) edge-sharing CuO2 chain (FFESC) cuprates. A homogeneous spin-1/2 chain model with a FM nearest-neighbor (NN), an antiferromagnetic (AFM) next-nearest-neighbor (NNN) inchain, and two diagonal AFM interchain couplings (ICs) analyzed within linear spin-wave theory (LSWT) reproduces well the observed strong dispersion along the chains and a weak one perpendicularly. The ratio R=|J_{a2}/J_{a1}| of the FM NN and the AFM NNN couplings is found as ~0.23, close to the critical point Rc=1/4 which separates ferromagnetically and antiferromagnetically correlated spiral magnetic ground states in single chains, whereas Rc>0.25 for coupled chains is considerably upshifted even for relatively weak IC. Although the measured dispersion can be described by homogeneous LSWT, the scattering intensity appears to be considerably reduced at ~11.5 and ~28 meV. The gap-like feature at 11.5 meV is attributed to magnon-phonon coupling whereas based on DMRG simulations of the dynamical structure factor the gap at 28 meV is considered to stem partly from quantum effects due to the AFM IC. Another contribution is ascribed to the intrinsic superstructure from the distorting incommensurate pattern of CaY cationic chains adjacent to the CuO2 ones. It gives rise to non-equivalent CuO4 units and Cu-O-Cu bond angles Phi and a resulting distribution of all exchange integrals. The J's fitted by homogeneous LSWT are regarded as average values. The record value of the FM NN integral J1=24 meV among FFESC cuprates can be explained by a non-universal Phi (not 90 deg.) and Cu-O bond length dependent anisotropic mean direct FM Cu-O exchange K_{pd}~120 meV. Enhanced K_{pd} values are also needed to compensate a significant AFM J_{dd} > ~6 meV., Comment: 36 pages

Published
2019
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5. Nab-paclitaxel weekly versus dose-dense solvent-based paclitaxel followed by dose-dense epirubicin plus cyclophosphamide in high-risk HR+/HER2− early breast cancer: results from the neoadjuvant part of the WSG-ADAPT-HR+/HER2− trial

Author

Gluz, O., Kuemmel, S., Nitz, U., Braun, M., Lüdtke-Heckenkamp, K., von Schumann, R., Darsow, M., Forstbauer, H., Potenberg, J., Uleer, C., Grischke, E.M., Aktas, B., Schumacher, C., zu Eulenburg, C., Kates, R., Jóźwiak, K., Graeser, M., Wuerstlein, R., Baehner, R., Christgen, M., Kreipe, H.H., and Harbeck, N.

Published
2023
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6. Event generators for high-energy physics experiments

Author

J. M. Campbell, M. Diefenthaler, T. J. Hobbs, S. Höche, J. Isaacson, F. Kling, S. Mrenna, J. Reuter, S. Alioli, J. R. Andersen, C. Andreopoulos, A. M. Ankowski, E. C. Aschenauer, A. Ashkenazi, M. D. Baker, J. L. Barrow, M. van Beekveld, G. Bewick, S. Bhattacharya, C. Bierlich, E. Bothmann, P. Bredt, A. Broggio, A. Buckley, A. Butter, J. M. Butterworth, E. P. Byrne, C. M. Carloni-Calame, S. Chakraborty, X. Chen, M. Chiesa, J. T. Childers, J. Cruz-Martinez, J. Currie, N. Darvishi, M. Dasgupta, A. Denner, F. A. Dreyer, S. Dytman, B. K. El-Menoufi, T. Engel, S. Ferrario Ravasio, D. Figueroa, L. Flower, J. R. Forshaw, R. Frederix, A. Friedland, S. Frixione, H. Gallagher, K. Gallmeister, S. Gardiner, R. Gauld, J. Gaunt, A. Gavardi, T. Gehrmann, A. Gehrmann-De Ridder, L. Gellersen, W. Giele, S. Gieseke, F. Giuli, E. W. N. Glover, M. Grazzini, A. Grohsjean, C. Gütschow, K. Hamilton, T. Han, R. Hatcher, G. Heinrich, I. Helenius, O. Hen, V. Hirschi, M. Höfer, J. Holguin, A. Huss, P. Ilten, S. Jadach, A. Jentsch, S. P. Jones, W. Ju, S. Kallweit, A. Karlberg, T. Katori, M. Kerner, W. Kilian, M. M. Kirchgaeßer, S. Klein, M. Knobbe, C. Krause, F. Krauss, J. Lang, J. -N. Lang, G. Lee, S. W. Li, M. A. Lim, J. M. Lindert, D. Lombardi, L. Lönnblad, M. Löschner, N. Lurkin, Y. Ma, P. Machado, V. Magerya, A. Maier, I. Majer, F. Maltoni, M. Marcoli, G. Marinelli, M. R. Masouminia, P. Mastrolia, O. Mattelaer, J. Mazzitelli, J. McFayden, R. Medves, P. Meinzinger, J. Mo, P. F. Monni, G. Montagna, T. Morgan, U. Mosel, B. Nachman, P. Nadolsky, R. Nagar, Z. Nagy, D. Napoletano, P. Nason, T. Neumann, L. J. Nevay, O. Nicrosini, J. Niehues, K. Niewczas, T. Ohl, G. Ossola, V. Pandey, A. Papadopoulou, A. Papaefstathiou, G. Paz, M. Pellen, G. Pelliccioli, T. Peraro, F. Piccinini, L. Pickering, J. Pires, W. Placzek, S. Plätzer, T. Plehn, S. Pozzorini, S. Prestel, C. T. Preuss, A. C. Price, S. Quackenbush, E. Re, D. Reichelt, L. Reina, C. Reuschle, P. Richardson, M. Rocco, N. Rocco, M. Roda, A. Rodriguez Garcia, S. Roiser, J. Rojo, L. Rottoli, G. P. Salam, M. Schönherr, S. Schuchmann, S. Schumann, R. Schürmann, L. Scyboz, M. H. Seymour, F. Siegert, A. Signer, G. Singh Chahal, A. Siódmok, T. Sjöstrand, P. Skands, J. M. Smillie, J. T. Sobczyk, D. Soldin, D. E. Soper, A. Soto-Ontoso, G. Soyez, G. Stagnitto, J. Tena-Vidal, O. Tomalak, F. Tramontano, S. Trojanowski, Z. Tu, S. Uccirati, T. Ullrich, Y. Ulrich, M. Utheim, A. Valassi, A. Verbytskyi, R. Verheyen, M. Wagman, D. Walker, B. R. Webber, L. Weinstein, O. White, J. Whitehead, M. Wiesemann, C. Wilkinson, C. Williams, R. Winterhalder, C. Wret, K. Xie, T-Z. Yang, E. Yazgan, G. Zanderighi, S. Zanoli, K. Zapp

Subjects
Physics, QC1-999
Abstract

We provide an overview of the status of Monte-Carlo event generators for high-energy particle physics. Guided by the experimental needs and requirements, we highlight areas of active development, and opportunities for future improvements. Particular emphasis is given to physics models and algorithms that are employed across a variety of experiments. These common themes in event generator development lead to a more comprehensive understanding of physics at the highest energies and intensities, and allow models to be tested against a wealth of data that have been accumulated over the past decades. A cohesive approach to event generator development will allow these models to be further improved and systematic uncertainties to be reduced, directly contributing to future experimental success. Event generators are part of a much larger ecosystem of computational tools. They typically involve a number of unknown model parameters that must be tuned to experimental data, while maintaining the integrity of the underlying physics models. Making both these data, and the analyses with which they have been obtained accessible to future users is an essential aspect of open science and data preservation. It ensures the consistency of physics models across a variety of experiments.

Published
2024
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8. International multicentre review of perioperative management and outcome for catecholamine‐producing tumours

Author

Groeben, H, Walz, MK, Nottebaum, BJ, Alesina, PF, Greenwald, A, Schumann, R, Hollmann, MW, Schwarte, L, Behrends, M, Rössel, T, Groeben, C, Schäfer, M, Lowery, A, Hirata, N, Yamakage, M, Miller, JA, Cherry, TJ, Nelson, A, Solorzano, CC, Gigliotti, B, Wang, TS, Wietasch, JKG, Friederich, P, Sheppard, B, Graham, PH, Weingarten, TN, and Sprung, J

Subjects
Biomedical and Clinical Sciences, Clinical Sciences, Patient Safety, Evaluation of treatments and therapeutic interventions, 6.4 Surgery, Good Health and Well Being, Adrenal Gland Neoplasms, Adrenalectomy, Adrenergic alpha-Antagonists, Adult, Female, Humans, Male, Middle Aged, Paraganglioma, Perioperative Care, Pheochromocytoma, Practice Patterns, Physicians', Treatment Outcome, Medical and Health Sciences, Surgery, Clinical sciences
Abstract

BackgroundSurgery for catecholamine-producing tumours can be complicated by intraoperative and postoperative haemodynamic instability. Several perioperative management strategies have emerged but none has been evaluated in randomized trials. To assess this issue, contemporary perioperative management and outcome data from 21 centres were collected.MethodsTwenty-one centres contributed outcome data from patients who had surgery for phaeochromocytoma and paraganglioma between 2000 and 2017. The data included the number of patients with and without α-receptor blockade, surgical and anaesthetic techniques, complications and perioperative mortality.ResultsAcross all centres, data were reported on 1860 patients with phaeochromocytoma or paraganglioma, of whom 343 underwent surgery without α-receptor blockade. The majority of operations (78·9 per cent) were performed using minimally invasive techniques, including 16·1 per cent adrenal cortex-sparing procedures. The cardiovascular complication rate was 5·0 per cent overall: 5·9 per cent (90 of 1517) in patients with preoperative α-receptor blockade and 0·9 per cent (3 of 343) among patients without α-receptor blockade. The mortality rate was 0·5 per cent overall (9 of 1860): 0·5 per cent (8 of 517) in pretreated and 0·3 per cent (1 of 343) in non-pretreated patients.ConclusionThere is substantial variability in the perioperative management of catecholamine-producing tumours, yet the overall complication rate is low. Further studies are needed to better define the optimal management approach, and reappraisal of international perioperative guidelines appears desirable.

Published
2020

11. Final results from the PERUSE study of first-line pertuzumab plus trastuzumab plus a taxane for HER2-positive locally recurrent or metastatic breast cancer, with a multivariable approach to guide prognostication

Author

Bachelot, T., Bouzid, K., Campone, M., Desmoulins, I., Coudert, B., Bondarenko, I., Nowecki, Z., Glogowska, I., Ciruelos Gil, E., Errihani, H., Dalenc, F., Ricci, F., Dieras, V., Kaufman, B., Paluch-Shimon, S., Wardley, A., Schneeweiss, A., Ferreira, A., Mano, M., Kalofonos, H., Andreetta, C., Puglisi, F., Montemurro, F., Barrett, S., Zhang, Q., Mavroudis, D., Matus, J., Villarreal Garza, C., Beato, C., Ismael, G., Hu, X., Abdel Azeem, H., Gaafar, R., Perrin, C., Kerbrat, P., Ettl, J., Paepke, S., Hitre, E., Lang, I., Trudeau, M., Verma, S., Li, H., Hoffmann, O., Aktas, B., Cariello, A., Cruciani, G., Tienghi, A., Tondini, C., Al-Twegieri, T., Loman, N., Laing, R., Miles, D., Brain, E., Fasching, P., Lux, M., Frassoldati, A., Aziz, Z., Salas, J., Streb, J., Krzemieniecki, K., Wronski, A., Garcia Garcia, J., Menjon Beltran, S., Cicin, I., Schmid, P., Gallagher, C., Turner, N., Tong, Z., Boer, K., Juhász, B., Horvath, Z., Bianchini, G., Gianni, L., Curigliano, G., Juarez Ramiro, A., Susnjar, S., Matos, E., Sevillano, E., Garcia Estevez, L., Gokmen, E., Uslu, R., Wildiers, H., Schutz, F., Cruz, M., Bourgeois, H., von Schumann, R., Stemmer, S., Dominguez, A., Morales-Vásques, F., Wojtukiewicz, M., Trifunovic, J., Echarri Gonzalez, M.J., Illarramendi Mañas, J., Martinez De Dueñas, E., Voitko, N., Hicks, J., Waters, S., Barrett-Lee, P., Wheatley, D., De Boer, R., Cocquyt, V., Jerusalem, G., Barrios, C., Panasci, L., Mattson, J., Tanner, M., Gozy, M., Vasilopoulos, G., Papandreou, C., Revesz, J., Battelli, N., Benedetti, G., Latini, L., Gridelli, C., Lazaro Leon, J., Alarcón Company, J., Arance Fernandez, A., Barnadas Molins, A., Calvo Plaza, I., Bratos, R., Gonzalez Martin, A., Izarzugaza Peron, Y., Klint, L., Kovalev, A., McCarthy, N., Yeo, B., Kee, D., Thomson, J., White, S., Greil, R., Wang, S., Artignan, X., Juhasz-Böess, I., Rody, A., Ngan, R., Dourleshter, F., Goldberg, H., Doni, L., Di Costanzo, F., Ferraù, F., Drobniene, M., Aleknavicius, E., Rashid, K., Costa, L., de la Cruz Merino, L., Garcia Saenz, J., López, R., Del Val Munoz, O., Ozyilkan, O., Azribi, F., Jaafar, H., Baird, R., Verrill, M., Beith, J., Petzer, A., Moreira de Andrade, J., Bernstein, V., Macpherson, N., Rayson, D., Saad Eldin, I., Achille, M., Augereau, P., Müller, V., Rasco, A., Evron, E., Katz, D., Berardi, R., Cascinu, S., De Censi, A., Gennari, A., El-Saghir, N., Ghosn, M., Oosterkamp, H.M., Van den Bosch, J., Kukulska, M., Kalinka, E., Alonso, J., Dalmau Portulas, E., Del Mar Gordon Santiago, M., Pelaez Fernandez, I., Aksoy, S., Altundag, K., Senol Coskun, H., Bozcuk, H., Shparyk, Y., Barraclough, L., Levitt, N., Panwar, U., Kelly, S., Rigg, A., Varughese, M., Castillo, C., Fein, L., Malik, L., Stuart-Harris, R., Singer, C., Stoeger, H., Samonigg, H., Feng, J., Cedeño, M., Ruohola, J., Berdah, J.-F., Goncalves, A., Orfeuvre, H., Grischke, E.-M., Simon, E., Wagner, S., Koumakis, G., Papazisis, K., Ben Baruch, N., Fried, G., Geffen, D., Karminsky, N., Peretz, T., Cavanna, L., Pedrazzioli, P., Grasso, D., Ruggeri, E., D’Auria, G., Moscetti, L., Juozaityte, E., Rodriguez Cid, J., Roerdink, H., Siddiqi, N., Passos Coelho, J., Arcediano Del Amo, A., Garcia Garre, E., García Gonzalez, M., Garcia-Palomo Perez, A., Herenandez Perez, C., Lopez Alvarez, P., Lopez De Ceballos, M.H., Martínez Jañez, N., Mele Olive, M., McAdam, K., Perren, T., Dunn, G., Humphreys, A., Taylor, W., Vera, R., Kaen, L., Andel, J., Steger, G., De Grève, J., Huizing, M., Hegg, R., Joy, A., Kuruvilla, P., Sehdev, S., Smiljanic, S., Kütner, R., Alexandre, J., Grosjean, J., Laplaige, P., Largillier, R., Maes, P., Martin, P., Pottier, V., Christensen, B., Khandan, F., Lück, H.-J., Zahm, D.-M., Fountzilas, G., Karavasilis, V., Safra, T., Inbar, M., Ryvo, L., Bonetti, A., Seles, E., Giacobino, A., Chavarri Guerra, Y., de Jongh, F., van der Velden, A., van Warmerdam, L., Vrijaldenhoven, S., Smorenburg, C.H., Cavero, M., Andres Conejero, R., Oltra Ferrando, A., Redondo Sanchez, A., Ribelles Entrena, N., Saura Grau, S., Viñas Vilaro, G., Bachmeier, K., Beresford, M., Butt, M., Joffe, J., Poole, C., Woodings, P., Chakraborti, P., Yordi, G., Woodward, N., Nobre, A., Luiz Amorim, G., Califaretti, N., Fox, S., Robidoux, A., Li, E., Li, N., Jiang, J., Soria, T., Padrik, P., Lahdenpera, O., Barletta, H., Dohollou, N., Genet, D., Prulhiere, K., Coeffic, D., Facchini, T., Vieillot, S., Catala, S., Teixeira, L., Hesse, T., Kühn, T., Ober, A., Repp, R., Schröder, W., Pectasides, D., Bodoky, G., Kahan, Z., Jiveliouk, I., Rosengarten, O., Rossi, V., Alabiso, O., Pérez Martínez, M., van de Wouw, A.J., Smok-Kalwat, J., Damasecno, M., Augusto, I., Sousa, G., Saadein, A., Abdelhafiez, N., Abulkhair, O., Antón Torres, A., Corbellas Aparicio, M., Llorente Domenech, R., Florián Jerico, J., Garcia Mata, J., Gil Raga, M., Galan Brotons, A., Llombart Cussac, A., Llorca Ferrandiz, C., Martinez Del Prado, P., Olier Garate, C., Rodriguez Sanchez, C., Sanchez Gomez, R., Santisteban Eslava, M., Soberino, J., Vidal Losada Garcia, M., Soto de Prado, D., Torrego Garcia, J., Vicente Rubio, E., Garcia, M., Murias Rosales, A., Granstam Björneklett, H., Narbe, U., Jafri, M., Rea, D., Newby, J., Jones, A., Westwell, S., Ring, A., Alonso, I., Rodríguez, R., Ciruelos, E., Peretz-Yablonski, T., Merot, J.-L., Trask, P., du Toit, Y., Pena-Murillo, C., Revelant, V., and Klingbiel, D.

Published
2021
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14. Ultrafast spin polarization control of Dirac fermions in topological insulators

Author

Sánchez-Barriga, J., Golias, E., Varykhalov, A., Braun, J., Yashina, L. V., Schumann, R., Minár, J., Ebert, H., Kornilov, O., and Rader, O.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

Three-dimensional topological insulators (TIs) are characterized by spin-polarized Dirac-cone surface states that are protected from backscattering by time-reversal symmetry. Control of the spin polarization of topological surface states (TSSs) using femtosecond light pulses opens novel perspectives for the generation and manipulation of dissipationless surface spin currents on ultrafast timescales. Using time-, spin-, and angle-resolved spectroscopy, we directly monitor for the first time the ultrafast response of the spin polarization of photoexcited TSSs to circularly-polarized femtosecond pulses of infrared light. We achieve all-optical switching of the transient out-of-plane spin polarization, which relaxes in about 1.2 ps. Our observations establish the feasibility of ultrafast optical control of spin-polarized Dirac fermions in TIs and pave the way for novel optospintronic applications at ultimate speeds., Comment: 9 pages, 4 figures

Published
2015
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18. Photoemission of Bi$_2$Se$_3$ with Circularly Polarized Light: Probe of Spin Polarization or Means for Spin Manipulation?

Author

Sánchez-Barriga, J., Varykhalov, A., Braun, J., Xu, S. -Y., Alidoust, N., Kornilov, O., Minár, J., Hummer, K., Springholz, G., Bauer, G., Schumann, R., Yashina, L. V., Ebert, H., Hasan, M. Z., and Rader, O.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

Topological insulators are characterized by Dirac cone surface states with electron spins aligned in the surface plane and perpendicular to their momenta. Recent theoretical and experimental work implied that this specific spin texture should enable control of photoelectron spins by circularly polarized light. However, these reports questioned the so far accepted interpretation of spin-resolved photoelectron spectroscopy. We solve this puzzle and show that vacuum ultraviolet photons (50-70 eV) with linear or circular polarization probe indeed the initial state spin texture of Bi$_2$Se$_3$ while circularly polarized 6 eV low energy photons flip the electron spins out of plane and reverse their spin polarization. Our photoemission calculations, considering the interplay between the varying probing depth, dipole selection rules and spin-dependent scattering effects involving initial and final states explain these findings, and reveal proper conditions for light-induced spin manipulation. This paves the way for future applications of topological insulators in opto-spintronic devices., Comment: Submitted for publication (2013)

Published
2013
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19. Radon Exposure and Incident Stroke Risk in the Women's Health Initiative

Author

Buchheit, Sophie F., primary, Collins, Jason M., additional, Anthony, Kurtis M., additional, Love, Shelly-Ann M., additional, Stewart, James D., additional, Gondalia, Rahul, additional, Huang, David Y., additional, Manson, JoAnn E., additional, Reiner, Alexander P., additional, Schwartz, Gary G., additional, Vitolins, Mara Z., additional, Schumann, R. Randall, additional, Smith, Richard L., additional, and Whitsel, Eric A., additional

Published
2024
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21. Analytical solution of a Hubbard model extended by nearest neighbour Coulomb and exchange interaction on a triangle and tetrahedron

Author

Schumann, R.

Subjects
Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Superconductivity
Abstract

The Hubbard model extended by either nearest-neighbour Coulomb correlation and/or nearest neighbour Heisenberg exchange is solved analytically for a triangle and tetrahedron. All eigenvalues and eigenvectors are given as functions of the model parameters in a closed form. The groundstate crossings and degeneracies are discussed both for the canonical and grand-canonical energy levels. The grand canonical potential and the electron occupation of the related cluster gases were calculated for arbitrary values (attractive and repulsive) of the three interaction constants. In the pure Hubbard model we found various steps in the electron occupation higher than one. It is shown that the various degeneracies of the grand-canonical energy levels are partially lifted by an antiferromagnetic exchange interaction, whereas a moderate ferromagnetic exchange modifies only slightly the results of the pure Hubbard model. A repulsive nn Coulomb correlation lifts these degeneracies completely. The relation of the cluster gas results to extended systems is discussed., Comment: 115 pages, 20 figures. If you do not intend to work with the eigenvalues and eigenvectors do NOT print the appendices (92 pages), instead print pages 1-11 (article) and 103-115 (figures)

Published
2007
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24. Thermal Remagnetization in Polycrystalline Permanent Magnets

Author

Schumann, R. and Jahn, L.

Subjects
Condensed Matter - Materials Science
Abstract

The thermal remagnetization (TR), i.e. the reentrance of magnetization upon heating in a steady-field demagnetized sample, is a common feature to the four types of polycrystalline permanent magnets, mainly utilized for practical purposes, i.e. barium ferrites, SmCo5, Sm2Co17 and NdFeB magnets. The effect is small for pinning controlled and large for nucleation controlled magnets. The effect is strongly dependent on the demagnetization factor and may reach nearly 100 per cent in SmCo5 samples measured in a closed circuit. The TR is very sensitive to a small superimposed steady field. The maximum effect and the position of the peak is dependent on the initial temperature. The direction of the TR is correlated with the temperature coefficient of the coercivity, resulting in a inverse TR in barium ferrite. The susceptibility of the thermally remagnetized samples is increased. Repeated cycles of steady-field demagnetization followed by heating result in the same TR. The phenomenology of TR and ITR is explained by means of a model taking into account both the internal field fluctuations due to grain interactions and the decay of single domain grains into multi-domain state. By taking the measured temperature dependencies of the coercivity and the saturation magnetization the theory is able to reproduce the experiments very well, allowing to determine the width of the field fluctuations, the width of the switching field distribution and an internal demagnetization factor as characteristics of the materials by fitting., Comment: 26 pages, 29 figures, 3 tables Contribution to the book-project: "Recent Research Developments In Magnetism And Magnetic Materials" by Transworld Research Network

Published
2003

26. Theory of Thermal Remagnetization of Permanent Magnets

Author

Schumann, R. and Jahn, L.

Subjects
Condensed Matter - Materials Science
Abstract

A self-consistent mean-field theory explaining the thermal remagnetization (TR) of polycrystalline permanent magnets is given. The influence of the environment of a grain is treated by an inclusion approximation, relating the field inside the grain to the local field outside by means of an internal demagnetization factor $n$. For the switching fields and the fluctuations of the local fields around the mean field Gaussian distributions of widths $\sigmas$ and $\sigmaf$ resp. are assumed. The isothermal hysteresis curve, the recoil curves, and the TR in dependence on the model parameters $n$, $\sigmas$, and $\sigmaf$ are calculated. Furthermore, the influence of the initial temperature and the strong dependence of the TR on the demagnetization factor of the sample are studied, and it is shown that for reasonable parameter sets TR effects up to 100 % are possible. The theoretical results correspond well with the experimental situation., Comment: 28 pages, 9 figures, Latex2e, accepted for publication in JMMM

Published
2001
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27. Thermodynamics of a 4-site Hubbard model by analytical diagonalization

Author

Schumann, R.

Subjects
Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Statistical Mechanics
Abstract

By use of the conservation laws a four-site Hubbard model coupled to a particle bath within an external magnetic field in z-direction was diagonalized. The analytical dependence of both the eigenvalues and the eigenstates on the interaction strength, the chemical potential and magnetic field was calculated. It is demonstrated that the low temperature behaviour is determined by a delicate interplay between many-particle states differing in electron number and spin if the electron density is away from half-filling. The grand partition sum is calculated and the specific heat, the suszeptibility as well as various correlation functions and spectral functions are given in dependence of the interaction strength, the electron occupation and the applied magnetic field. Furthermore, for both the grand canonical and the canonical ensemble the so called crossing points of the suszeptibility are calculated. They confirm the universal value predicted by Vollhardt [1]., Comment: 42 pages, including 9 tables and 22 figures, RevTeX 3.1

Published
2001
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29. Perturbation Expansion of the Partition Sum for any Temperature

Author

Schumann, R.

Subjects
Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Statistical Mechanics
Abstract

Based on the special properties of Liouville eigenoperators a perturbation theory for the partition sum is given. It is applicable for any temperature and includes the case of degenerate Hamiltonians. To demonstrate the reliability of the method, the second order correction to the atomic limit grand canonical potential of the Hubbard model is calculated and compared to results known from the literature., Comment: 22 pages, latex, needs PSTricks-macro from Princeton University, new version with some minor corrections of mistyped formulas

Published
1998

35. Dissecting the genetic heterogeneity of gastric cancer

Author

Hess, T., Maj, C., Gehlen, J., Borisov, O., Haas, S. L., Gockel, I., Vieth, M., Piessen, G., Alakus, H., Vashist, Y., Pereira, C., Knapp, M., Schuller, V., Quaas, A., Grabsch, H. I., Trautmann, J., Malecka-Wojciesko, E., Mokrowiecka, A., Speller, J., Mayr, A., Schroder, J., Hillmer, A. M., Heider, D., Lordick, F., Perez-Aisa, A., Campo, R., Espinel, J., Geijo, F., Thomson, C., Bujanda, L., Sopena, F., Lanas, A., Pellise, M., Pauligk, C., Goetze, T. O., Zelck, C., Reingruber, J., Hassanin, E., Elbe, P., Alsabeah, S., Lindblad, M., Nilsson, M., Kreuser, N., Thieme, R., Tavano, F., Pastorino, Roberta, Arzani, D., Persiani, Roberto, Jung, J. -O., Nienhuser, H., Ott, K., Schumann, R. R., Kumpf, O., Burock, S., Arndt, V., Jakubowska, A., Lawniczak, M., Moreno, V., Martin, V., Kogevinas, M., Pollan, M., Dabrowska, J., Salas, A., Cussenot, O., Boland-Auge, A., Daian, D., Deleuze, J. -F., Salvi, E., Teder-Laving, M., Tomasello, G., Ratti, M., Senti, C., De Re, V., Steffan, A., Holscher, A. H., Messerle, K., Bruns, C. J., Sivins, A., Bogdanova, I., Skieceviciene, J., Arstikyte, J., Moehler, M., Lang, H., Grimminger, P. P., Kruschewski, M., Vassos, N., Schildberg, C., Lingohr, P., Ridwelski, K., Lippert, H., Fricker, N., Krawitz, P., Hoffmann, Christian Pieter, Nothen, M. M., Veits, L., Izbicki, J. R., Mostowska, A., Martinon-Torres, F., Cusi, D., Adolfsson, R., Cancel-Tassin, G., Hoblinger, A., Rodermann, E., Ludwig, M., Keller, G., Metspalu, A., Brenner, H., Heller, J., Neef, M., Schepke, M., Dumoulin, F. L., Hamann, L., Cannizzaro, Rino, Ghidini, Maria Candida, Plassmann, D., Geppert, M., Malfertheiner, P., Gehlen, O., Skoczylas, T., Majewski, M., Lubinski, J., Palmieri, O., Boccia, Stefania, Latiano, A., Aragones, N., Schmidt, T., Dinis-Ribeiro, M., Medeiros, R., Al-Batran, S. -E., Leja, M., Kupcinskas, J., Garcia-Gonzalez, M. A., Venerito, M., Schumacher, J., Pastorino R. (ORCID:0000-0001-5013-0733), Persiani R. (ORCID:0000-0002-1537-5097), Hoffmann P., Cannizzaro R., Ghidini M., Boccia S. (ORCID:0000-0002-1864-749X), Hess, T., Maj, C., Gehlen, J., Borisov, O., Haas, S. L., Gockel, I., Vieth, M., Piessen, G., Alakus, H., Vashist, Y., Pereira, C., Knapp, M., Schuller, V., Quaas, A., Grabsch, H. I., Trautmann, J., Malecka-Wojciesko, E., Mokrowiecka, A., Speller, J., Mayr, A., Schroder, J., Hillmer, A. M., Heider, D., Lordick, F., Perez-Aisa, A., Campo, R., Espinel, J., Geijo, F., Thomson, C., Bujanda, L., Sopena, F., Lanas, A., Pellise, M., Pauligk, C., Goetze, T. O., Zelck, C., Reingruber, J., Hassanin, E., Elbe, P., Alsabeah, S., Lindblad, M., Nilsson, M., Kreuser, N., Thieme, R., Tavano, F., Pastorino, Roberta, Arzani, D., Persiani, Roberto, Jung, J. -O., Nienhuser, H., Ott, K., Schumann, R. R., Kumpf, O., Burock, S., Arndt, V., Jakubowska, A., Lawniczak, M., Moreno, V., Martin, V., Kogevinas, M., Pollan, M., Dabrowska, J., Salas, A., Cussenot, O., Boland-Auge, A., Daian, D., Deleuze, J. -F., Salvi, E., Teder-Laving, M., Tomasello, G., Ratti, M., Senti, C., De Re, V., Steffan, A., Holscher, A. H., Messerle, K., Bruns, C. J., Sivins, A., Bogdanova, I., Skieceviciene, J., Arstikyte, J., Moehler, M., Lang, H., Grimminger, P. P., Kruschewski, M., Vassos, N., Schildberg, C., Lingohr, P., Ridwelski, K., Lippert, H., Fricker, N., Krawitz, P., Hoffmann, Christian Pieter, Nothen, M. M., Veits, L., Izbicki, J. R., Mostowska, A., Martinon-Torres, F., Cusi, D., Adolfsson, R., Cancel-Tassin, G., Hoblinger, A., Rodermann, E., Ludwig, M., Keller, G., Metspalu, A., Brenner, H., Heller, J., Neef, M., Schepke, M., Dumoulin, F. L., Hamann, L., Cannizzaro, Rino, Ghidini, Maria Candida, Plassmann, D., Geppert, M., Malfertheiner, P., Gehlen, O., Skoczylas, T., Majewski, M., Lubinski, J., Palmieri, O., Boccia, Stefania, Latiano, A., Aragones, N., Schmidt, T., Dinis-Ribeiro, M., Medeiros, R., Al-Batran, S. -E., Leja, M., Kupcinskas, J., Garcia-Gonzalez, M. A., Venerito, M., Schumacher, J., Pastorino R. (ORCID:0000-0001-5013-0733), Persiani R. (ORCID:0000-0002-1537-5097), Hoffmann P., Cannizzaro R., Ghidini M., and Boccia S. (ORCID:0000-0002-1864-749X)

Abstract

Background: Gastric cancer (GC) is clinically heterogenous according to location (cardia/non-cardia) and histopathology (diffuse/intestinal). We aimed to characterize the genetic risk architecture of GC according to its subtypes. Another aim was to examine whether cardia GC and oesophageal adenocarcinoma (OAC) and its precursor lesion Barrett's oesophagus (BO), which are all located at the gastro-oesophageal junction (GOJ), share polygenic risk architecture. Methods: We did a meta-analysis of ten European genome-wide association studies (GWAS) of GC and its subtypes. All patients had a histopathologically confirmed diagnosis of gastric adenocarcinoma. For the identification of risk genes among GWAS loci we did a transcriptome-wide association study (TWAS) and expression quantitative trait locus (eQTL) study from gastric corpus and antrum mucosa. To test whether cardia GC and OAC/BO share genetic aetiology we also used a European GWAS sample with OAC/BO. Findings: Our GWAS consisting of 5816 patients and 10,999 controls highlights the genetic heterogeneity of GC according to its subtypes. We newly identified two and replicated five GC risk loci, all of them with subtype-specific association. The gastric transcriptome data consisting of 361 corpus and 342 antrum mucosa samples revealed that an upregulated expression of MUC1, ANKRD50, PTGER4, and PSCA are plausible GC-pathomechanisms at four GWAS loci. At another risk locus, we found that the blood-group 0 exerts protective effects for non-cardia and diffuse GC, while blood-group A increases risk for both GC subtypes. Furthermore, our GWAS on cardia GC and OAC/BO (10,279 patients, 16,527 controls) showed that both cancer entities share genetic aetiology at the polygenic level and identified two new risk loci on the single-marker level. Interpretation: Our findings show that the pathophysiology of GC is genetically heterogenous according to location and histopathology. Moreover, our findings point to common molecular me

Published
2023

36. A tale of two islands: tectonic and orbital controls on marine terrace reoccupation, Channel Islands National Park, California, USA.

Author

Muhs, Daniel R., Groves, Lindsey T., Simmons, Kathleen R., Schumann, R. Randall, and DeVogel, Stephen B.

Subjects
NATIONAL parks & reserves, INTERGLACIALS, STRONTIUM isotopes, ISLANDS, PLEISTOCENE Epoch, SEA level, MILANKOVITCH cycles, TERRACING
Abstract

In areas of low uplift rate on the Pacific Coast of North America, reoccupation of emergent marine terraces by later high sea‐stands has been hypothesised to explain the existence of thermally anomalous fauna (mixtures of warm and cool species) of last interglacial age. If uplift rates have been low for much of the Quaternary, it follows that higher (older) terraces should also show evidence of reoccupation. Strontium isotope analyses of fossils from a high‐elevation marine terrace on Anacapa Island, California, yield ages ranging from ~2.4–2.3 Ma to ~1.4–1.5 Ma. These results indicate that terrace reoccupation and fossil mixing on Anacapa Island could have taken place over several interglacial periods in the early Pleistocene. Terrace reoccupation over this time period is likely a function of both a low uplift rate and the timing of orbital forcing of glacial–interglacial cycles. Climate change in the early Pleistocene was modulated by the 41 ka obliquity cycle, and glacial–interglacial cycles were much shorter than later in the Pleistocene. Nearby San Miguel Island also has evidence of terrace reoccupation, with Sr isotope ages of shells from several high‐elevation terraces ranging from ~1.21–1.25 Ma to ~0.43–0.50 Ma. However, the frequency of terrace reoccupation was lower than on Anacapa Island. The uplift rate of San Miguel Island is higher than that of Anacapa Island and terraces formed when glacial–interglacial cycles were longer. The frequency of marine terrace reoccupation is controlled by the rate of tectonic uplift and the timing of orbital forcing of sea level change during glacial–interglacial cycles. [ABSTRACT FROM AUTHOR]

Published
2024
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44. Regression einer idiopathischen epiretinalen Gliose – Kasuistik und Überlegungen zum Mechanismus

Author

Framme, C., Feltgen, N., Schumann, R., Stichtenoth, D. O., and Hattenbach, L. O.

Abstract

Bei Vorliegen einer symptomatischen epiretinalen Gliose wird im klinischen Alltag in der Regel eine Pars-plana-Vitrektomie mit Membranpeeling zur Entfernung der Membran indiziert. Nach gängiger klinischer Erfahrung existiert nahezu keine selbstständige Regression einer solchen epiretinalen Membran und somit einer alleinigen Abheilung der Pathologie. Beschrieben wird daher der ungewöhnliche Fall einer beidseitigen selbstständigen Regression einer idiopathischen epiretinalen Gliose mit Makulaschichtforamen bei einem 73-jährigen Patienten. Überlegungen zum möglichen Mechanismus werden auf Basis der vorhandenen Literatur vorgestellt. Diese beinhalten die Trennung entzündlicher vs. nichtentzündlicher Membranen, mögliche Separation einzelner Schichten in Abhängigkeit vom Status der hinteren Glaskörpergrenzmembran, aber auch das mögliche Wirken proteolytischer Systeme im Bereich des hinteren Glaskörpers. Es stellt sich schließlich die Frage, ob Patienten vor möglicher Operation über diesen Umstand mit aufgeklärt werden müssen.

Published
2024
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50. LBA17 Survival outcome of neoadjuvant endocrine therapy + trastuzumab and pertuzumab (ET+T+P) vs. de-escalated chemotherapy (CT)+T+P in hormone receptor positive (HR+)/HER2+ early breast cancer (EBC): WSG-TP-II trial

Author

Gluz, O., Nitz, U.A., Christgen, M., Kummel, S., Holtschmidt, J., Schumacher, J., Hartkopf, A.D., Luedtke-Heckenkamp, K., Just, M., von Schumann, R., Polata, S., Schinköthe, T., Graeser-Mayer, M.K., Kates, R.E., Würstlein, R., Kreipe, H., and Harbeck, N.

Published
2024
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