Roberts Enns

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BACKGROUND Natalizumab, a humanized monoclonal antibody against alpha4 integrin, inhibits leukocyte adhesion and migration into inflamed tissue. METHODS We conducted two controlled trials to evaluate natalizumab as induction and maintenance therapy in patients with active Crohn's disease. In the first trial, 905 patients were randomly assigned to receive(More)
BACKGROUND Prednisone and methylprednisolone are well absorbed orally and have lower treatment costs than IV methylprednisolone, but concern that low-dose corticosteroid may cause increased disease activity and that high oral doses may cause gastric ulceration inhibits use of oral therapy for MS attacks. METHODS Gastric mucosal injury, detected by(More)
4-Aminopyridine (4-AP) is an investigational drug for the treatment of neurologic disorders including multiple sclerosis (MS). Until recently, relatively little was known about 4-AP toxicity in overdose; the only recorded cases involved neurologic symptoms ranging from mild parasthesias to tonic-clonic seizures. We report a case of accidental 4-AP overdose(More)
The robust (solitonlike) nature of bistable light bullets is demonstrated numerically for some illustrative models through three-dimensional switching simulations and collision studies. Bistable light bullets are propagating, spheroidal, bright optical solitons characterized by different sizes and intensity profiles but with the same energy.
The dynamics of bistable soliton propagation and switching in a fiber whose intensity-dependent refractive index is described by the linear plus smooth-step model is numerically investigated under conditions where the fiber is evanescently coupled to an identical, initially empty, parallel fiber. The initially empty fiber can perform a number of useful(More)
Bistable dark solitary-wave solutions (bistable holes) to the generalized nonlinear Schrödinger equation are shown to exist in the normal dispersion regime for nonlinearities that are Kerr-like at low intensities, rise sufficiently rapidly at intermediate intensities, and become Kerr-like again or approach a constant value at large intensities. The bistable(More)
Using a particular nonlinearity (the linear + smooth step model) as an illustrative example, it is demonstrated numerically that switching between bistable soliton states of the highly nonlinear (generalized) Schrödinger equation can occur. This numerical simulation may serve as a model of optical switching between distinctly different soliton states in a(More)
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