48 research outputs found
Regulating STING in health and disease.
The presence of cytosolic double-stranded DNA molecules can trigger multiple innate immune signalling pathways which converge on the activation of an ER-resident innate immune adaptor named "STimulator of INterferon Genes (STING)". STING has been found to mediate type I interferon response downstream of cyclic dinucleotides and a number of DNA and RNA inducing signalling pathway. In addition to its physiological function, a rapidly increasing body of literature highlights the role for STING in human disease where variants of the STING proteins, as well as dysregulated STING signalling, have been implicated in a number of inflammatory diseases. This review will summarise the recent structural and functional findings of STING, and discuss how STING research has promoted the development of novel therapeutic approaches and experimental tools to improve treatment of tumour and autoimmune diseases
Tutorial on Nonlinear Reduced Order Modeling for Nominally Cyclic Symmetric Structures and Rotating Machinery
Application of Microbial-Induced Carbonate Precipitation for Soil Improvement via Ureolysis
Experimental Nonlinear Vibration Analysis of a Shrouded Bladed Disk Model on a Rotating Test Rig
Soil Stabilization Against Water Erosion via Calcite Precipitation by Plant-Derived Urease
Stabilization is often necessary to improve the stiffness, strength and durability of both natural and compacted soils. Soils are typically stabilized via the addition of hydraulic binders, such as cement and lime, which present however relatively high carbon and energy footprints. Alternative stabilization techniques are therefore explored to minimize environmental impact while preserving good material properties. Among these techniques, enzyme induced calcite precipitation (EICP) has gained prominence in recent years. EICP exploits the action of the urease enzyme to catalyze the hydrolysis of urea and to produce carbonate ions, which then react with calcium ions inside the pore water to cause precipitation of calcium carbonate (i.e. calcite). The precipitated mineral bonds particles together, thus improving the hydro-mechanical characteristics of the soil. This paper presents a preliminary investigation on the use of plant-derived urease, instead of pure reagent-grade urease, to minimize environmental and financial costs. The urease enzyme is obtained from a liquid soybeans extract, inside which urea and calcium chloride are dissolved. This stabilizing solution is then mixed with a silty clay to produce stabilized samples, which are subjected to water erosion tests
Mitigation of the liquefaction potential of soil by Ca-carbonate precipitation induced by indigenous urease-producing Staphylococcus sp. IR-103
Novel Parametric Reduced Order Model for Aeroengine Blade Dynamics
The work proposes a reduced order modelling (ROM) technique for turbofan engine blades. The aim is to develop a simplified structural layout that allows describing the dynamic behaviour associated with the first six modes of fullscale fan blades. This is done by introducing equivalent frame models for the blade, which can be tailored to represent coupled flexural/torsional mode shapes, the relevant natural frequencies and static masses. Both 2D and 3D frame models are considered with initial configurations obtained from structural identification equations. The frame configurations are refined via an optimization process based on simulated annealing with stochastic tunnelling. The cost function comprises a linear combination of relative errors on the vibration frequencies, the individual modal assurance criteria (MAC) and the static mass. We demonstrate that an optimized 3D frame can represent the blade dynamic behaviour with a 6 % error on the MAC and a 1 % error on the associated modal frequencies. The approach proposed in this paper is considerably more accurate than ROMs based on single equivalent beams, either Euler–Bernoulli or Timoshenko, and highly computational efficient. Therefore, this technique is suitable for application to the analysis of mistuned bladed discs, particularly for determining the sensitivity to manufacturing and assembly tolerances in joints. © The Society for Experimental Mechanics, Inc. 2014
