Suchergebnisse

Axial spondyloarthritis (axSpA) is a chronic inflammatory rheumatic disease characterized by inflammation and new bone formation in the axial skeleton. AxSpA is considered a spectrum of disease that includes two subtypes identified by the Assessment in SpondyloArthritis International Society classification criteria, namely, radiographic (r-axSpA usually referred to as ankylosing spondylitis) and non-radiographic axSpA (nr-axSpA). Although the burden of disease appears similar between the two classified subtypes, the degree of inflammation, as assessed by magnetic resonance imaging and C-reactive protein, and the degree of new bone formation are significantly higher in r-axSpA than in nr-axSpA. Nevertheless, axSpA is considered one disease with different courses. International guidelines for the management of axSpA have outlined treatment goals focused on control of signs and symptoms, inflammation, prevention of progressive structural damage, preservation of physical function, normalization of social participation and improvement of quality of life. The pathogenesis of axSpA has not been completely elucidated to date. A strong link between human leukocyte antigen B27 and axSpA, however, has been identified, and the success of anti-tumour necrosis factor and anti-interleukin (IL)-17A therapy has highlighted some of the key pro-inflammatory cytokines involved. The anti-IL-17A monoclonal antibody secukinumab is approved for the treatment of ankylosing spondylitis and nr-axSpA in the European Union and United States. In this narrative review, we discuss data for secukinumab in axSpA from randomized controlled trials, including MEASURE trials in AS and PREVENT in nr-axSpA, and real-world evidence.

This thesis focuses on the injuries of the lumbar spine due to high rate loading, using both cadaveric experiments and numerical modelling. Insurgent warfare has been characterised by the use of improvised explosive devices, often targeting military personnel inside vehicles. Those incidents are associated with spinal injuries of poor clinical outcome. Currently, spinal injury tolerance levels do not exist for the loading seen by blast casualties, and the biomechanics of the lumbar spine are not understood under impact loading. Experimental and numerical models were developed to investigate the response of single segments and bi-segments of the lumbar spine under impact loading conditions. A novel methodology for controlling posture and ensuring axial loading during experiments was developed. A single segment numerical model was developed using the finite element method; the load transmission through the segment and its stress distributions were analysed. A bi-segment numerical model was also developed and three different positions on the sagittal plane were simulated; flexed (10 ͦ), neutral (0 ͦ) and extended (-5 ͦ). Differences between postures were predicted and areas prone to injury were identified. The neutral posture was found to be the most severe for the same loading conditions. Injurious impact tests of bi-segment cadaveric specimens were performed for the aforementioned postures, and the neutral posture was found to sustain injuries associated with the poorest outcome compared to the flexed or extended specimens. The methodologies and technologies developed in this thesis can be used further to look into the injury biomechanics aspects of the lumbar spine and used as a test-bed for assessing current and develop new mitigation strategies. Immediate next steps would be to include the rest of the lumbar spine in the numerical model and then the pelvis so that the loading pathway from the seat through to the spine can be quantified. ; Open Access

17 latex pages.- 7 figures.- 2 tables.- Some typos corrected ; We present a new determination of the N Delta axial form factors from neutrino induced pion production data. For this purpose, the model of Hernandez et al. [Phys. Rev. D 76, 033005 (2007)] is improved by partially restoring unitarity. This is accomplished by imposing Watson's theorem on the dominant vector and axial multipoles. As a consequence, a larger C-5(A) (0), in good agreement with the prediction from the off-diagonal Goldberger-Treiman relation, is now obtained. ; We thank Callum Wilkinson for making the results of Ref. [63] available to us. This research has been supported by the Spanish Ministerio de Economia y Competitividad (MINECO) and the European fund for regional development (FEDER) under Contracts No. FIS2011-28853-C02-01, No. FIS2011-28853-C02-02, No. FPA2013-47443-C2-2-P, No. FIS2014-51948-C2-1-P, No. FIS2014-51948-C2-2-P, No. FIS2014-57026-REDT, and No. SEV-2014-0398; by Generalitat Valenciana under Contract No. PROMETEOII/2014/0068; and by the European Union HadronPhysics3 project, Grant No. 283286. ; Peer reviewed

Numerical investigation of an axial flow rotor is carried out for its performance characterization and aerodynamic behavior during the design and off-design operating conditions. The study focuses on capturing the transonic flow features from the choke point (CP) to the near stall (NS) point in the rotor. This includes the analysis of passage shock structure, its movement in the blade passage with varying back-pressure, shock boundary layer interaction, tip leakage flow structure, and resulting losses. The study is carried out from 60 % to 100 % of the design speed using steady and unsteady RANS simulations. Three turbulence models, namely; SST, k-ε, and Reynolds stress models, are employed. The SST model predicted the closest approximation to the experimental data. The rotor aerodynamic performance is predicted in terms of total pressure ratio, efficiency, and flow contours. Unsteady analysis revealed that the primary and secondary tip leakage vortices, combined with the suction side tip corner separation, are the major instabilities near the stall region.