9,141 research outputs found
New insights into the biomechanics of Legg-Calvé-Perthes’ disease: The role of epiphyseal skeletal immaturity in vascular obstruction
ObjectivesLegg–Calvé–Perthes’ disease (LCP) is an idiopathic osteonecrosis of the femoral head that is most common in children between four and eight years old. The factors that lead to the onset of LCP are still unclear; however, it is believed that interruption of the blood supply to the developing epiphysis is an important factor in the development of the condition.MethodsFinite element analysis modelling of the blood supply to the juvenile epiphysis was investigated to understand under which circumstances the blood vessels supplying the femoral epiphysis could become obstructed. The identification of these conditions is likely to be important in understanding the biomechanics of LCP.ResultsThe results support the hypothesis that vascular obstruction to the epiphysis may arise when there is delayed ossification and when articular cartilage has reduced stiffness under compression.ConclusionThe findings support the theory of vascular occlusion as being important in the pathophysiology of Perthes disease
The Muon Anomalous Magnetic Moment in the Reduced Minimal 3-3-1 Model
We study the muon anomalous magnetic moment in the context of
the reduced minimal 3-3-1 model recently proposed in the literature. In
particular, its spectrum contains a doubly charged scalar () and
gauge boson (), new singly charged vectors () and a
boson, each of which might give a sizeable contribution to the
. We compute the 1-loop contributions from all these new particles
to the . We conclude that the doubly charged vector boson provides
the dominant contribution, and by comparing our results with the experimental
constraints we derive an expected value for the scale of symmetry breaking TeV. We also note that, if the
discrepancy in the anomalous moment is resolved in the future without this
model then the constraints will tighten to requiring TeV with
current precision, and will entirely rule out the model if the expected
precision is achieved by the future experiment at Fermilab.Comment: 19 pages, 4 figure
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