The aim of this study is to implement the clinical use of the three-dimensional (3D) design and printing technology in pediatric pathologies requiring immobilization. We describe the manufacturing process of the 3D device in place of the plaster cast usually applied to a child 48/72 h after the access to the Trauma Center Traumatology Hub. This procedure had already been performed at Level II, Trauma Center, Campania Region, Orthopaedic Division of Santobono Children’s Hospital, Naples, Italy. The operative phase was performed by two 3D printers and a scanner in the bioengineering laboratory of the hospital’s outpatient area. The phase of software elaboration requires close cooperation among physicians and engineers. We decided to use a model with a double-shell design and holes varying in width to ensure complete ventilation and lightness of the device. We chose to treat nondisplaced metaphyseal distal fractures of the radius in 18 patients enrolled from January 2017 to November 2017. The flow chart includes clinical and radiological examinations of every enrolled child, collecting information required by the program and its elaboration by bioengineers, and then transfer of the results to 3D printers. The child, immobilized by a temporary splint, wore his 3D device after 12/24 h. Then, he underwent serial check-ups in which the effectiveness and appropriateness of the treatment were clinically monitored and evaluated using subjective scales: visual analogue scale and patient-rated wrist evaluation. All the fractures consolidated both radiologically and clinically after the treatment, with no complications reported. Only one partial breakage of the device happened because of an accidental fall. The statistical analysis of the visual analogue scale and patient-rated wrist evaluation data shows that children’s activities of everyday life improved during the immobilization thanks to this treatment. This first study shows that using a 3D device instead of a traditional plaster cast can be an effective alternative approach in the treatment of pediatric nondisplaced metaphyseal distal radius fractures, with high overall patient satisfaction. We believe that 3D technology could be extended to the treatment of more complex fractures; this will be the subject of our second study.
Flavoprotein oxidoreductases are members of a large protein family of specialized dehydrogenases, which include type II NADH dehydrogenase, pyridine nucleotide-disulphide oxidoreductases, ferredoxin-NAD+ reductases, NADH oxidases, and NADH peroxidases, playing a crucial role in the metabolism of several prokaryotes and eukaryotes. Although several studies have been performed on single members or protein subgroups of flavoprotein oxidoreductases, a comprehensive analysis on structure–function relationships among the different members and subgroups of this great dehydrogenase family is still missing. Here, we present a structural comparative analysis showing that the investigated flavoprotein oxidoreductases have a highly similar overall structure, although the investigated dehydrogenases are quite different in functional annotations and global amino acid composition. The different functional annotation is ascribed to their participation in species-specific metabolic pathways based on the same biochemical reaction, i.e., the oxidation of specific cofactors, like NADH and FADH2. Notably, the performed comparative analysis sheds light on conserved sequence features that reflect very similar oxidation mechanisms, conserved among flavoprotein oxidoreductases belonging to phylogenetically distant species, as the bacterial type II NADH dehydrogenases and the mammalian apoptosis-inducing factor protein, until now retained as unique protein entities in Bacteria/Fungi or Animals, respectively. Furthermore, the presented computational analyses will allow consideration of FAD/NADH oxidoreductases as a possible target of new small molecules to be used as modulators of mitochondrial respiration for patients affected by rare diseases or cancer showing mitochondrial dysfunction, or antibiotics for treating bacterial/fungal/protista infections.
This paper develops a novel modelling approach for ventilation flow in tunnels at ambient conditions (i.e. cold flow). The complexity of full CFD models of low in tunnels or the inaccuracies of simplistic assumptions are avoided by efficiently combining a simple, mono-dimensional approach to model tunnel regions where the flow is fully developed, with detailed CFD solutions where flow conditions require 3D resolution. This multiscale method has not previously been applied to tunnel flows. The low computational cost of this method is of great value when hundreds of possible ventilation scenarios need to be studied. The multi-scale approach is able to provide detailed local flow conditions, where required, with a significant reduction in the overall computational time. The coupling procedures and the numerical error induced by this new approach are studied and discussed. The paper describes a comparison between numerical results and experimental data recorded within a real tunnel underlining how the developed methodology can be used as a valid design tool for any tunnel ventilation system. This work sets the foundations for the coupling of fire-induced flows and ventilation systems where further complexities are introduced by the hot gas plume and smoke stratification.
This paper applies a novel and fast modelling approach to simulate tunnel ventilation flows during fires. The complexity and high cost of full CFD models and the inaccuracies of simplistic zone or analytical models are avoided by efficiently combining mono-dimensional (1D) and CFD (3D) modelling techniques. A simple 1D network approach is used to model tunnel regions where the flow is fully developed (far field), and a detailed CFD representation is used where flow conditions require 3D resolution (near field). This multi-scale method has previously been applied to simulate tunnel ventilation systems including jet fans, vertical shafts and portals (Colella et al., Build Environ 44 (12): 2357-2367, 2009) and it is applied here to include the effect of fire. Both direct and indirect coupling strategies are investigated and compared for steady state conditions. The methodology has been applied to a modern tunnel of 7 m diameter and 1.2 km in length. Different fire scenarios ranging from 10 MW to 100 MW are investigated with a variable number of operating jet fans. Comparison of cold flow cases with fire cases provides a quantification of the fire throttling effect, which is seen to be large and to reduce the flow by more than 30% for a 100 MW fire. Emphasis has been given to the discussion of the different coupling procedures and the control of the numerical error. Compared to the full CFD solution, the maximum flow field error can be reduced to less than few percents, but providing a reduction of two orders of magnitude in computational time. The much lower computational cost is of great engineering value, especially for parametric and sensitivity studies required in the design or assessment of ventilation and fire safety systems.
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