The aim of the present study was to investigate the additive manufacturing process for high consistency nanocellulose. Unlike thermoformable plastics, wood derived nanocelluloses are typically processed as aqueous dispersions because they are not melt-processable on their own. The ability to use nanocellulose directly in additive manufacturing broadens the possibilities regarding usable raw materials and achievable properties thereof. Modern additive manufacturing systems are capable of depositing nanocellulose with micrometer precision, which enables the printing of accurate three-dimensional wet structures. Typically, these wet structures are produced from dilute aqueous fibrillar dispersions. As a consequence of the high water content, the structures deform and shrink during drying unless the constructs are freeze-dried. While freeze-drying preserves the geometry, it results in high porosity which manifests as poor mechanical and barrier properties. Herein, we study an additive manufacturing process for high consistency enzymatically fibrillated cellulose nanofibers in terms of printability, shape retention, structure, and mechanical properties. Particular emphasis is placed on quantitative shape analysis based on 3D scanning, point cloud analysis, and x-ray microtomography. Despite substantial volumetric as well as anisotropic deformation, we demonstrate repeatability of the printed construct and its properties.

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BackgroundObesity and osteoporosis, two possibly related conditions, are rapidly expanding health concerns in modern society. Both of them are associated with sedentary life style and nutrition. To investigate the effects of diet-induced obesity and voluntary physical activity we used high resolution micro-computed tomography (μCT) together with peripheral quantitative computed tomography (pQCT) to examine the microstructure of the distal femoral metaphysis in mice.MethodsForty 7-week-old male C57BL/6J mice were assigned to 4 groups: control (C), control + running (CR), high-fat diet (HF), and high-fat diet + running (HFR). After a 21-week intervention, all the mice were sacrificed and the left femur dissected for pQCT and μCT measurements.ResultsThe mice fed the high-fat diet showed a significant weight gain (over 70% for HF and 60% for HFR), with increased epididymal fat pad mass and impaired insulin sensitivity. These obese mice had significantly higher trabecular connectivity density, volume, number, thickness, area and mass, and smaller trabecular separation. At the whole bone level, they had larger bone circumference and cross-sectional area and higher density-weighted maximal, minimal, and polar moments of inertia. Voluntary wheel running decreased all the cortical bone parameters, but increased the trabecular mineral density, and decreased the pattern factor and structure model index towards a more plate-like structure.ConclusionsThe results suggest that in mice the femur adapts to obesity by improving bone strength both at the whole bone and micro-structural level. Adaptation to running exercise manifests itself in increased trabecular density and improved 3D structure, but in a limited overall bone growth

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Summary Nuclear positioning and dynamic interactions of viral proteins with nuclear substructures play essential roles during infection with DNA viruses. Visualization of the intranuclear interactions and motility of the parvovirus replication protein (NS1) in living cells gives insight into specific parvovirus protein–cellular structure interactions. Confocal analysis of highly synchronized infected Norden Laboratory Feline Kidney cells showed accumulation of nuclear NS1 in discrete interchromosomal foci. NS1 fused with enhanced yellow fluorescence protein (NS1‐EYFP) provided a marker in live cells for dynamics of NS1 traced by photobleaching techniques. Fluorescence Recovery after Photobleaching suggested that the NS1 protein is not freely diffusing but undergoes transient interactions with nuclear compartments. Fluorescence Loss in Photobleaching demonstrated for the first time the shuttling of a parvoviral protein between the nucleus and the cytoplasm as assayed with NS1‐EYFP. Finally, time‐lapse imaging of infected cells revealed that the intranuclear distribution of NS1‐EYFP evolves dramatically starting from the formation of NS1 foci and proceeding to a homogenous distribution extending throughout the nucleus.