@inproceedings{SaparinGowinZaikinetal.2003, author = {Saparin, Peter and Gowin, Wolfgang and Zaikin, Alexei and Prohaska, Steffen}, title = {Quantification of changes in human bone structure at different skeletal locations using measures of complexity}, booktitle = {2nd European Congress 'Achievements in Space Medicine into Health Care Practice and Industry'}, address = {Berlin-Adlershof}, year = {2003}, language = {en} } @inproceedings{GowinSaparinProhaskaetal.2003, author = {Gowin, Wolfgang and Saparin, Peter and Prohaska, Steffen and Hege, Hans-Christian and Belle, Stefan and Felsenberg, Dieter}, title = {Architectural Reasons for the Femoral Neck Fracture Location}, booktitle = {2nd European Congress 'Achievements in Space Medicine into Health Care Practice and Industry'}, address = {Berlin-Adlershof}, year = {2003}, language = {en} } @inproceedings{ZaikinSaparinProhaskaetal.2003, author = {Zaikin, Alexei and Saparin, Peter and Prohaska, Steffen and Kurths, J{\"u}rgen and Gowin, Wolfgang}, title = {2D and 3D bone modelling for analysis of changes in the bone architecture and for evaluation of structural measures.}, booktitle = {2nd European Congress 'Achievements in Space Medicine into Health Care Practice and Industry'}, address = {Berlin-Adlershof}, year = {2003}, language = {en} } @inproceedings{ThomsenKollerLaibetal.2003, author = {Thomsen, Jesper and Koller, Bruno and Laib, Andreas and Prohaska, Steffen and Giehl, Michael and Gowin, Wolfgang}, title = {Comparison between Static Histomorphometric Measures Conducted by Traditionally 2D Histomorphometry and 3D μ-CT in Human Tibial Biopsies}, booktitle = {2nd European Congress 'Achievements in Space Medicine into Health Care Practice and Industry'}, address = {Berlin-Adlershof}, year = {2003}, language = {en} } @inproceedings{HegeWeinkaufProhaskaetal.2004, author = {Hege, Hans-Christian and Weinkauf, Tino and Prohaska, Steffen and Hutanu, Andrei}, title = {Distributed visualization and analysis of fluid dynamics data}, booktitle = {Proc. Fourth International Symposium on Advanced Fluid Information and Transdisciplinary Fluid Integration}, address = {Sendai, Japan}, pages = {145 -- 150}, year = {2004}, language = {en} } @inproceedings{HegeSchirmacherWesterhoffetal.2002, author = {Hege, Hans-Christian and Schirmacher, Hartmut and Westerhoff, Malte and Lamecker, Hans and Prohaska, Steffen and Zachow, Stefan}, title = {From Image Data to Three-Dimensional Models - Case Studies on the Impact of 3D Patient Models}, booktitle = {Proceedings of the Japan Korea Computer Graphics Conference 2002}, publisher = {Kanazawa University}, address = {Kanazawa City, Ishikawa, Japan}, year = {2002}, language = {en} } @article{ProhaskaHegeGiehletal.2002, author = {Prohaska, Steffen and Hege, Hans-Christian and Giehl, Michael and Gowin, Wolfgang}, title = {Visual Analysis of Trabecular Bone Structure}, volume = {9 (1)}, journal = {Journal of Gravitational Physiology}, pages = {171 -- 172}, year = {2002}, language = {en} } @misc{GowinSaparinFelsenbergetal.2002, author = {Gowin, Wolfgang and Saparin, Peter and Felsenberg, Dieter and Kurths, J{\"u}rgen and Zaikin, Alexei and Prohaska, Steffen and Hege, Hans-Christian}, title = {Regional Structural Skeletal Discordance Assessed by Measures of Complexity}, year = {2002}, language = {en} } @article{ZaikinSaparinProhaskaetal.2002, author = {Zaikin, Alexei and Saparin, Peter and Prohaska, Steffen and Kurths, J{\"u}rgen and Gowin, Wolfgang}, title = {Bone Modeling and Structural Measures of Complexity}, volume = {9}, journal = {Journal of Gravitational Physiology}, doi = {10.1016/j.actaastro.2005.01.007}, pages = {175 -- 176}, year = {2002}, language = {en} } @article{GowinSaparinProhaskaetal.2002, author = {Gowin, Wolfgang and Saparin, Peter and Prohaska, Steffen and Hege, Hans-Christian and Felsenberg, Dieter}, title = {Femoral Neck Fractures: Reasons for the Most Common Location of Fractures}, volume = {73}, journal = {Acta Orthop. Scand. (Suppl. 304)}, pages = {26}, year = {2002}, language = {en} } @article{CassotLauwersFouardetal.2006, author = {Cassot, Francis and Lauwers, Frederic and Fouard, C{\´e}line and Prohaska, Steffen and Lauwer-Cances, Valerie}, title = {A novel three-dimensional computer assisted method for a quantitative study of microvascular networks of the human cerebral cortex}, volume = {13}, journal = {Microcirculation}, pages = {15 -- 32}, year = {2006}, language = {en} } @inproceedings{ProhaskaHege2002, author = {Prohaska, Steffen and Hege, Hans-Christian}, title = {Fast Visualization of Plane-Like Structures in Voxel Data}, booktitle = {Proceedings of IEEE Visualization 2002}, editor = {J. Moorhead, Robert and Gross, Markus and I. Joy, Kenneth}, publisher = {IEEE Computer Society Press}, address = {Boston MA, USA}, doi = {10.1109/VISUAL.2002.1183753}, pages = {29 -- 36}, year = {2002}, language = {en} } @misc{HombergBaumWiebeletal.2013, author = {Homberg, Ulrike and Baum, Daniel and Wiebel, Alexander and Prohaska, Steffen and Hege, Hans-Christian}, title = {Definition, Extraction, and Validation of Pore Structures in Porous Materials}, issn = {1438-0064}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-42510}, year = {2013}, abstract = {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.}, language = {en} } @article{BuchmannKaplanPowelletal.2019, author = {Buchmann, Jens and Kaplan, Bernhard and Powell, Samuel and Prohaska, Steffen and Laufer, Jan}, title = {3D quantitative photoacoustic tomography using an adjoint radiance Monte Carlo model and gradient descent}, volume = {24}, journal = {Journal of Biomedical Optics}, number = {6}, doi = {10.1117/1.JBO.24.6.066001}, pages = {066001}, year = {2019}, abstract = {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 Gr{\"u}neisen parameter from in silico 3D phantom images for different radiance approximations. The scattering coefficient was assumed to be homogeneous and known a priori.}, language = {en} } @misc{BuchmannKaplanPowelletal.2019, author = {Buchmann, Jens and Kaplan, Bernhard and Powell, Samuel and Prohaska, Steffen and Laufer, Jan}, title = {3D quantitative photoacoustic tomography using an adjoint radiance Monte Carlo model and gradient descent}, issn = {1438-0064}, doi = {10.1117/1.JBO.24.6.066001}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-72995}, year = {2019}, abstract = {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 Gr{\"u}neisen parameter from in silico 3D phantom images for different radiance approximations. The scattering coefficient was assumed to be homogeneous and known a priori.}, language = {en} } @article{OzelKulkarniHasanetal.2019, author = {Ozel, Mehmet Neset and Kulkarni, Abhishek and Hasan, Amr and Brummer, Josephine and Moldenhauer, Marian and Daumann, Ilsa-Maria and Wolfenberg, Heike and Dercksen, Vincent J. and Kiral, Ferdi Ridvan and Weiser, Martin and Prohaska, Steffen and von Kleist, Max and Hiesinger, Peter Robin}, title = {Serial synapse formation through filopodial competition for synaptic seeding factors}, volume = {50}, journal = {Developmental Cell}, number = {4}, doi = {10.1016/j.devcel.2019.06.014}, pages = {447 -- 461}, year = {2019}, abstract = {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.}, language = {en} } @article{ZhukovaHiepenKnausetal.2017, author = {Zhukova, Yulia and Hiepen, Christian and Knaus, Petra and Osterland, Marc and Prohaska, Steffen and Dunlop, John W. C. and Fratzl, Peter and Skorb, Ekaterina V.}, title = {The role of titanium surface nanotopography on preosteoblast morphology, adhesion and migration}, journal = {Advanced Healthcare Materials}, doi = {10.1002/adhm.201601244}, year = {2017}, abstract = {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.}, language = {en} } @inproceedings{RitterProhaskaBrandetal.2011, author = {Ritter, Zully and Prohaska, Steffen and Brand, R. and Friedmann, A. and Hege, Hans-Christian and Goebbels, J{\"u}rgen and Felsenberg, Dieter}, title = {Osteocytes number and volume in osteoporotic and in healthy bone biopsies analysed using Synchrotron CT: a pilot study}, booktitle = {Proc. ISB 2011}, year = {2011}, language = {en} } @inproceedings{StreicherPaetschSeileretal.2011, author = {Streicher, Doreen and Paetsch, Olaf and Seiler, Robert and Prohaska, Steffen and Krause, Martin and Boller, Christian}, title = {3-D-Visualisierung von Radar- und Ultraschallecho-Daten mit ZIBAmira}, booktitle = {Proc. DGZfP-Jahrestagung 2011}, year = {2011}, language = {de} } @inproceedings{PaetschBaumEhrigetal.2012, author = {Paetsch, Olaf and Baum, Daniel and Ehrig, Karsten and Meinel, Dietmar and Prohaska, Steffen}, title = {Vergleich automatischer 3D-Risserkennungsmethoden f{\"u}r die quantitative Analyse der Schadensentwicklung in Betonproben mit Computer-Tomographie}, booktitle = {Tagungsband der DACH Jahrestagung 2012}, year = {2012}, language = {de} }