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All hierarchical levels in bone are known to contribute to its mechanical behavior. The basic building block is the mineralized collagen fibril which is assembled into larger structures with varying fibrillar organization. The collagen organization increases from unordered woven bone in the callus which is gradually replaced by higher ordered lamellar bone during bone development and healing and finally results in cortical lamellar bone with highest degree of organization. The structural and mechanical description of these organizational motifs is not yet complete. We investigated a femoral osteotomy mouse model and analyzed newly formed callus tissue and mature lamellar bone in the cortex. This model exhibits three bone types with different fibrillar organization: (i) woven, (ii) moderate lamellar and (iii) lamellar. Using high resolution synchrotron small angle X-ray scattering in combination with back-scattered electron imaging we characterized the ultrastructure of the different regions in terms of degree of mineralization, averaged mineral particle thickness and mineral particle orientation. We further used microindentation to correlate hardness, induced crack lengths and crack patterns with the bone ultrastructure. The newly formed callus tissue contains highly mineralized woven bone islands, featuring thick but poorly ordered mineral particles. Such islands are surrounded by layers of lamellar bone with a low mineralization level and thin but well aligned particles. Callus tissue shows lower hardness values and longer cracks than the cortex. Callus woven bone exhibits shorter cracks than callus lamellar bone. However, the poorly mineralized callus lamellar bone shows crack propagation mechanisms similar to cortical bone due to its very similar lamellar organization and high degree of mineral particle orientation. In conclusion we demonstrate that woven and increasingly higher oriented lamellar bone do not only differ in collagen fibril organization, but also that the amount, orientation and different shape of mineral particles are also likely to contribute to the reduced mechanical competence of woven as compared to lamellar bone. This may explain why many organisms replace less organized bone types with higher organized ones. [ABSTRACT FROM AUTHOR]

X-ray scattering experiments at synchrotron sources are characterized by large and constantly increasing amounts of data. The great number of files generated during a synchrotron experiment is often a limiting factor in the analysis of the data, since appropriate software is rarely available to perform fast and tailored data processing. Furthermore, it is often necessary to perform online data reduction and analysis during the experiment in order to interactively optimize experimental design. This article presents an open-source software package developed to process large amounts of data from synchrotron scattering experiments. These data reduction processes involve calibration and correction of raw data, one- or two-dimensional integration, as well as fitting and further analysis of the data, including the extraction of certain parameters. The software, DPDAK (directly programmable data analysis kit), is based on a plug-in structure and allows individual extension in accordance with the requirements of the user. The article demonstrates the use of DPDAK for on- and offline analysis of scanning small-angle X-ray scattering (SAXS) data on biological samples and microfluidic systems, as well as for a comprehensive analysis of grazing-incidence SAXS data. In addition to a comparison with existing software packages, the structure of DPDAK and the possibilities and limitations are discussed. [ABSTRACT FROM AUTHOR]