TY - CHAP A1 - Saparin, Peter A1 - Gowin, Wolfgang A1 - Zaikin, Alexei A1 - Prohaska, Steffen T1 - Quantification of changes in human bone structure at different skeletal locations using measures of complexity T2 - 2nd European Congress ’Achievements in Space Medicine into Health Care Practice and Industry’ Y1 - 2003 CY - Berlin-Adlershof ER - TY - CHAP A1 - Gowin, Wolfgang A1 - Saparin, Peter A1 - Prohaska, Steffen A1 - Hege, Hans-Christian A1 - Belle, Stefan A1 - Felsenberg, Dieter T1 - Architectural Reasons for the Femoral Neck Fracture Location T2 - 2nd European Congress ’Achievements in Space Medicine into Health Care Practice and Industry’ Y1 - 2003 CY - Berlin-Adlershof ER - TY - CHAP A1 - Zaikin, Alexei A1 - Saparin, Peter A1 - Prohaska, Steffen A1 - Kurths, Jürgen A1 - Gowin, Wolfgang T1 - 2D and 3D bone modelling for analysis of changes in the bone architecture and for evaluation of structural measures. T2 - 2nd European Congress ’Achievements in Space Medicine into Health Care Practice and Industry’ Y1 - 2003 CY - Berlin-Adlershof ER - TY - CHAP A1 - Thomsen, Jesper A1 - Koller, Bruno A1 - Laib, Andreas A1 - Prohaska, Steffen A1 - Giehl, Michael A1 - Gowin, Wolfgang T1 - Comparison between Static Histomorphometric Measures Conducted by Traditionally 2D Histomorphometry and 3D μ-CT in Human Tibial Biopsies T2 - 2nd European Congress ’Achievements in Space Medicine into Health Care Practice and Industry’ Y1 - 2003 CY - Berlin-Adlershof ER - TY - CHAP A1 - Hege, Hans-Christian A1 - Weinkauf, Tino A1 - Prohaska, Steffen A1 - Hutanu, Andrei T1 - Distributed visualization and analysis of fluid dynamics data T2 - Proc. Fourth International Symposium on Advanced Fluid Information and Transdisciplinary Fluid Integration Y1 - 2004 SP - 145 EP - 150 CY - Sendai, Japan ER - TY - CHAP A1 - Hege, Hans-Christian A1 - Schirmacher, Hartmut A1 - Westerhoff, Malte A1 - Lamecker, Hans A1 - Prohaska, Steffen A1 - Zachow, Stefan T1 - From Image Data to Three-Dimensional Models - Case Studies on the Impact of 3D Patient Models T2 - Proceedings of the Japan Korea Computer Graphics Conference 2002 Y1 - 2002 PB - Kanazawa University CY - Kanazawa City, Ishikawa, Japan ER - TY - JOUR A1 - Prohaska, Steffen A1 - Hege, Hans-Christian A1 - Giehl, Michael A1 - Gowin, Wolfgang T1 - Visual Analysis of Trabecular Bone Structure JF - Journal of Gravitational Physiology Y1 - 2002 VL - 9 (1) SP - 171 EP - 172 ER - TY - GEN A1 - Gowin, Wolfgang A1 - Saparin, Peter A1 - Felsenberg, Dieter A1 - Kurths, Jürgen A1 - Zaikin, Alexei A1 - Prohaska, Steffen A1 - Hege, Hans-Christian T1 - Regional Structural Skeletal Discordance Assessed by Measures of Complexity Y1 - 2002 ER - TY - JOUR A1 - Zaikin, Alexei A1 - Saparin, Peter A1 - Prohaska, Steffen A1 - Kurths, Jürgen A1 - Gowin, Wolfgang T1 - Bone Modeling and Structural Measures of Complexity JF - Journal of Gravitational Physiology Y1 - 2002 U6 - https://doi.org/10.1016/j.actaastro.2005.01.007 VL - 9 SP - 175 EP - 176 ER - TY - JOUR A1 - Gowin, Wolfgang A1 - Saparin, Peter A1 - Prohaska, Steffen A1 - Hege, Hans-Christian A1 - Felsenberg, Dieter T1 - Femoral Neck Fractures: Reasons for the Most Common Location of Fractures JF - Acta Orthop. Scand. (Suppl. 304) Y1 - 2002 VL - 73 SP - 26 ER - TY - JOUR A1 - Cassot, Francis A1 - Lauwers, Frederic A1 - Fouard, Céline A1 - Prohaska, Steffen A1 - Lauwer-Cances, Valerie T1 - A novel three-dimensional computer assisted method for a quantitative study of microvascular networks of the human cerebral cortex JF - Microcirculation Y1 - 2006 VL - 13 SP - 15 EP - 32 ER - TY - CHAP A1 - Prohaska, Steffen A1 - Hege, Hans-Christian ED - J. Moorhead, Robert ED - Gross, Markus ED - I. Joy, Kenneth T1 - Fast Visualization of Plane-Like Structures in Voxel Data T2 - Proceedings of IEEE Visualization 2002 Y1 - 2002 U6 - https://doi.org/10.1109/VISUAL.2002.1183753 SP - 29 EP - 36 PB - IEEE Computer Society Press CY - Boston MA, USA ER - TY - GEN A1 - Homberg, Ulrike A1 - Baum, Daniel A1 - Wiebel, Alexander A1 - Prohaska, Steffen A1 - Hege, Hans-Christian T1 - Definition, Extraction, and Validation of Pore Structures in Porous Materials N2 - An intuitive and sparse representation of the void space of porous materials supports the efficient analysis and visualization of interesting qualitative and quantitative parameters of such materials. We introduce definitions of the elements of this void space, here called pore space, based on its distance function, and present methods to extract these elements using the extremal structures of the distance function. The presented methods are implemented by an image processing pipeline that determines pore centers, pore paths and pore constrictions. These pore space elements build a graph that represents the topology of the pore space in a compact way. The representations we derive from μCT image data of realistic soil specimens enable the computation of many statistical parameters and, thus, provide a basis for further visual analysis and application-specific developments. We introduced parts of our pipeline in previous work. In this chapter, we present additional details and compare our results with the analytic computation of the pore space elements for a sphere packing in order to show the correctness of our graph computation. T3 - ZIB-Report - 13-56 Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-42510 SN - 1438-0064 ER - TY - JOUR A1 - Buchmann, Jens A1 - Kaplan, Bernhard A1 - Powell, Samuel A1 - Prohaska, Steffen A1 - Laufer, Jan T1 - 3D quantitative photoacoustic tomography using an adjoint radiance Monte Carlo model and gradient descent JF - Journal of Biomedical Optics N2 - Quantitative photoacoustic tomography aims to recover maps of the local concentrations of tissue chromophores from multispectral images. While model-based inversion schemes are promising approaches, major challenges to their practical implementation include the unknown fluence distribution and the scale of the inverse problem. This paper describes an inversion scheme based on a radiance Monte Carlo model and an adjoint-assisted gradient optimization that incorporates fluence-dependent step sizes and adaptive moment estimation. The inversion is shown to recover absolute chromophore concentrations, blood oxygen saturation and the Grüneisen parameter from in silico 3D phantom images for different radiance approximations. The scattering coefficient was assumed to be homogeneous and known a priori. Y1 - 2019 U6 - https://doi.org/10.1117/1.JBO.24.6.066001 VL - 24 IS - 6 SP - 066001 ER - TY - GEN A1 - Buchmann, Jens A1 - Kaplan, Bernhard A1 - Powell, Samuel A1 - Prohaska, Steffen A1 - Laufer, Jan T1 - 3D quantitative photoacoustic tomography using an adjoint radiance Monte Carlo model and gradient descent N2 - Quantitative photoacoustic tomography aims to recover maps of the local concentrations of tissue chromophores from multispectral images. While model-based inversion schemes are promising approaches, major challenges to their practical implementation include the unknown fluence distribution and the scale of the inverse problem. This paper describes an inversion scheme based on a radiance Monte Carlo model and an adjoint-assisted gradient optimization that incorporates fluence-dependent step sizes and adaptive moment estimation. The inversion is shown to recover absolute chromophore concentrations, blood oxygen saturation and the Grüneisen parameter from in silico 3D phantom images for different radiance approximations. The scattering coefficient was assumed to be homogeneous and known a priori. T3 - ZIB-Report - 19-16 KW - quantitative photoacoustic imaging KW - blood oxygen saturation KW - inverse problem KW - model-based inversion KW - Monte Carlo KW - spectral unmixing Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-72995 SN - 1438-0064 ER - TY - JOUR A1 - Ozel, Mehmet Neset A1 - Kulkarni, Abhishek A1 - Hasan, Amr A1 - Brummer, Josephine A1 - Moldenhauer, Marian A1 - Daumann, Ilsa-Maria A1 - Wolfenberg, Heike A1 - Dercksen, Vincent J. A1 - Kiral, Ferdi Ridvan A1 - Weiser, Martin A1 - Prohaska, Steffen A1 - von Kleist, Max A1 - Hiesinger, Peter Robin T1 - Serial synapse formation through filopodial competition for synaptic seeding factors JF - Developmental Cell N2 - Following axon pathfinding, growth cones transition from stochastic filopodial exploration to the formation of a limited number of synapses. How the interplay of filopodia and synapse assembly ensures robust connectivity in the brain has remained a challenging problem. Here, we developed a new 4D analysis method for filopodial dynamics and a data-driven computational model of synapse formation for R7 photoreceptor axons in developing Drosophila brains. Our live data support a 'serial synapse formation' model, where at any time point only a single 'synaptogenic' filopodium suppresses the synaptic competence of other filopodia through competition for synaptic seeding factors. Loss of the synaptic seeding factors Syd-1 and Liprin-α leads to a loss of this suppression, filopodial destabilization and reduced synapse formation, which is sufficient to cause the destabilization of entire axon terminals. Our model provides a filopodial 'winner-takes-all' mechanism that ensures the formation of an appropriate number of synapses. Y1 - 2019 U6 - https://doi.org/10.1016/j.devcel.2019.06.014 VL - 50 IS - 4 SP - 447 EP - 461 ER - TY - JOUR A1 - Zhukova, Yulia A1 - Hiepen, Christian A1 - Knaus, Petra A1 - Osterland, Marc A1 - Prohaska, Steffen A1 - Dunlop, John W. C. A1 - Fratzl, Peter A1 - Skorb, Ekaterina V. T1 - The role of titanium surface nanotopography on preosteoblast morphology, adhesion and migration JF - Advanced Healthcare Materials N2 - Surface structuring of titanium-based implants with appropriate nanotopographies can significantly modulate their impact on the biological behavior of cells populating these implants. Implant assisted bone tissue repair and regeneration require functional adhesion and expansion of bone progenitors. The surface nanotopography of implant materials used to support bone healing and its effect on cell behavior, in particular cell adhesion, spreading, expansion, and motility, is still not clearly understood. The aim of this study is to investigate preosteoblast proliferation, adhesion, morphology, and migration on different titanium materials with similar surface chemistry, but distinct nanotopographical features. Sonochemical treatment and anodic oxidation were employed to fabricate disordered – mesoporous titania (TMS), and ordered – titania nanotubular (TNT) topographies respectively. The morphological evaluation revealed a surface dependent shape, thickness, and spreading of cells owing to different adherence behavior. Cells were polygonal-shaped and well-spread on glass and TMS, but displayed an elongated fibroblast-like morphology on TNT surfaces. The cells on glass however, were much flatter than on nanostructured surfaces. Both nanostructured surfaces impaired cell adhesion, but TMS was more favorable for cell growth due to its support of cell attachment and spreading in contrast to TNT. Quantitative wound healing assay in combination with live-cell imaging revealed that cells seeded on TMS surfaces migrated in close proximity to neighboring cells and less directed when compared to the migratory behavior on other surfaces. The results indicate distinctly different cell adhesion and migration on ordered and disordered titania nanotopographies, providing important information that could be used in optimizing titanium-based scaffold design to foster bone tissue growth and repair. Y1 - 2017 U6 - https://doi.org/10.1002/adhm.201601244 ER - TY - CHAP A1 - Ritter, Zully A1 - Prohaska, Steffen A1 - Brand, R. A1 - Friedmann, A. A1 - Hege, Hans-Christian A1 - Goebbels, Jürgen A1 - Felsenberg, Dieter T1 - Osteocytes number and volume in osteoporotic and in healthy bone biopsies analysed using Synchrotron CT: a pilot study T2 - Proc. ISB 2011 Y1 - 2011 ER - TY - CHAP A1 - Streicher, Doreen A1 - Paetsch, Olaf A1 - Seiler, Robert A1 - Prohaska, Steffen A1 - Krause, Martin A1 - Boller, Christian T1 - 3-D-Visualisierung von Radar- und Ultraschallecho-Daten mit ZIBAmira T2 - Proc. DGZfP-Jahrestagung 2011 Y1 - 2011 ER - TY - CHAP A1 - Paetsch, Olaf A1 - Baum, Daniel A1 - Ehrig, Karsten A1 - Meinel, Dietmar A1 - Prohaska, Steffen T1 - Vergleich automatischer 3D-Risserkennungsmethoden für die quantitative Analyse der Schadensentwicklung in Betonproben mit Computer-Tomographie T2 - Tagungsband der DACH Jahrestagung 2012 Y1 - 2012 ER -