| 1. |
- Kreins, AY, et al.
(författare)
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Human TYK2 deficiency: Mycobacterial and viral infections without hyper-IgE syndrome
- 2015
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Ingår i: The Journal of experimental medicine. - : Rockefeller University Press. - 1540-9538 .- 0022-1007. ; 212:10, s. 1641-1662
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Tidskriftsartikel (refereegranskat)abstract
- Autosomal recessive, complete TYK2 deficiency was previously described in a patient (P1) with intracellular bacterial and viral infections and features of hyper-IgE syndrome (HIES), including atopic dermatitis, high serum IgE levels, and staphylococcal abscesses. We identified seven other TYK2-deficient patients from five families and four different ethnic groups. These patients were homozygous for one of five null mutations, different from that seen in P1. They displayed mycobacterial and/or viral infections, but no HIES. All eight TYK2-deficient patients displayed impaired but not abolished cellular responses to (a) IL-12 and IFN-α/β, accounting for mycobacterial and viral infections, respectively; (b) IL-23, with normal proportions of circulating IL-17+ T cells, accounting for their apparent lack of mucocutaneous candidiasis; and (c) IL-10, with no overt clinical consequences, including a lack of inflammatory bowel disease. Cellular responses to IL-21, IL-27, IFN-γ, IL-28/29 (IFN-λ), and leukemia inhibitory factor (LIF) were normal. The leukocytes and fibroblasts of all seven newly identified TYK2-deficient patients, unlike those of P1, responded normally to IL-6, possibly accounting for the lack of HIES in these patients. The expression of exogenous wild-type TYK2 or the silencing of endogenous TYK2 did not rescue IL-6 hyporesponsiveness, suggesting that this phenotype was not a consequence of the TYK2 genotype. The core clinical phenotype of TYK2 deficiency is mycobacterial and/or viral infections, caused by impaired responses to IL-12 and IFN-α/β. Moreover, impaired IL-6 responses and HIES do not appear to be intrinsic features of TYK2 deficiency in humans.
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| 2. |
- Araoz Ramos, Joseph A., et al.
(författare)
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Numerical simulation for the design analysis of kinematic Stirling engines
- 2015
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 159, s. 633-650
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Tidskriftsartikel (refereegranskat)abstract
- The Stirling engine is a closed-cycle regenerative system that presents good theoretical properties. These include a high thermodynamic efficiency, low emissions levels thanks to a controlled external heat source, and multi-fuel capability among others. However, the performance of actual prototypes largely differs from the mentioned theoretical potential. Actual engine prototypes present low electrical power outputs and high energy losses. These are mainly attributed to the complex interaction between the different components of the engine, and the challenging heat transfer and fluid dynamics requirements. Furthermore, the integration of the engine into decentralized energy systems such as the Combined Heat and Power systems (CHP) entails additional complications. These has increased the need for engineering tools that could assess design improvements, considering a broader range of parameters that would influence the engine performance when integrated within overall systems. Following this trend, the current work aimed to implement an analysis that could integrate the thermodynamics, and the thermal and mechanical interactions that influence the performance of kinematic Stirling engines. In particular for their use in Combined Heat and Power systems. The mentioned analysis was applied for the study of an engine prototype that presented very low experimental performance. The numerical methodology was selected for the identification of possible causes that limited the performance. This analysis is based on a second order Stirling engine model that was previously developed and validated. The simulation allowed to evaluate the effect that different design and operational parameters have on the engine performance, and consequently different performance curves were obtained. These curves allowed to identify ranges for the charged pressure, temperature ratio, heat exchangers dimensions, crank phase angle and crank mechanical effectiveness, where the engine performance was improved. In addition, the curves also permitted to recognise ranges were the design parameters could drastically reduce the brake power and efficiency. The results also showed that the design of the engine is affected by the conditions imposed by the CHP interactions, and that the engine could reach a brake power closer to 832 W with a corresponding brake efficiency of 26% when the adequate design parameters were considered. On the other hand, the performance could also be very low; as the reported in experimental tests, with brake power measurements ranging 52-120W.
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| 3. |
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| 4. |
- Tudisco, Erika, et al.
(författare)
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Neutron imaging of rock mechanics experiments
- 2015
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Ingår i: Integrating Innovations of Rock Mechanics : Proceedings of the 8th South American Congress on Rock Mechanics, 15–18 November 2015, Buenos Aires, Argentina - Proceedings of the 8th South American Congress on Rock Mechanics, 15–18 November 2015, Buenos Aires, Argentina. - 9781614996040 - 9781614996057 ; , s. 231-236
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Konferensbidrag (refereegranskat)abstract
- Understanding the mechanical behaviour of porous rocks and how this influences the fluid flow is key in a number of resource engineering challenges, in particular hydrocarbon production and CO2 sequestration. Deformation in these porous materials is, in general, not homogeneous, as deformation localises into narrow shear or compaction bands, which might then evolve into fractures. These local deformation features can act as barriers or conduits for fluid flow, depending on their evolution and resultant properties. This work focusses on achieving quantitative understanding of how localised deformation (shear or compaction bands and fractures) can change (local and global) permeability in porous rocks. In particular the aim is to overcome limitations of traditional methods for permeability measurement, which consider bulk sample measurements, and do not provide a good understanding of the permeability variations in the presence of material heterogeneity, e.g., localised deformations. Better understanding of the controlling factors on permeability evolution due to localised deformation requires mapping of the full permeability and strain fields through test specimens. Neutron tomography, in combination with 3D-volumetric Digital Image Correlation (3DDIC) is used to measure deformation and fast neutron radiography is used to visualise fluid-flow through the characterised deformed samples.
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