Support material is often utilised in additive manufacture to enable geometries that are not otherwise self-supporting. Despite the associated opportunities for innovation, the use of support material also introduces a series of limitations: additional material cost, cost of removal of support material, potential contamination of biocompatible materials, and entrapment of support material within cellular structures. This work presents a strategy for minimising the use of support material by comparing the geometric limits of an additive manufacture process to the build angles that exist within a proposed geometry. This method generates a feasibility map of the feasible build orientations for a proposed geometry with a given process. The method is applied to polyhedra that are suitable for close packing to identify space-filling tessellated structures that can be self-supporting. The integrity of an FDM process is quantified, and using the associated feasibility map, self-supporting polyhedra are manufactured. These polyhedra are integrated with non-trivial geometries to achieve a reduction in consumed material of approximately 50%. Nomenclature

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Background: Asthma is a disease with chronic airway inflammation, whereby the airway hyper-reactivity increases. Oxidative stress balance plays a critical role in asthma. Objectives: The present study aimed to evaluate serum glutathione peroxidase (GPX) enzyme activity and selenium levels in patients with asthma. Methods: This case-control study was conducted on 64 children aged 1 - 5 years, 32 subjects as controls, and 32 subjects with asthma who were selected randomly. The serum GPX activity and selenium levels of the studied subjects were determined spectrophotometrically. Results: The present study showed that serum GPX activity and Se levels of patients with asthma were significantly lower than those of controls (P < 0.001, P < 0.05, respectively). Conclusions: Reduction of serum GPX activity and Se concentration in patients could have a potential role in the pathogenesis and modulation of asthma. Micronutrient supplementation of Se may be beneficial in asthma.