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- Frohlich, J., et al.
(författare)
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Solitary wave dynamics in an external potential
- 2004
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Ingår i: Communications in Mathematical Physics. - : Springer Science and Business Media LLC. - 0010-3616 .- 1432-0916. ; 250:3, s. 613-642
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Tidskriftsartikel (refereegranskat)abstract
- We study the behavior of solitary-wave solutions of some generalized nonlinear Schrodinger equations with an external potential. The equations have the feature that in the absence of the external potential, they have solutions describing inertial motions of stable solitary waves. We consider solutions of the equations with a non-vanishing external potential corresponding to initial conditions close to one of these solitary wave solutions and show that, over a large interval of time, they describe a solitary wave whose center of mass motion is a solution of Newton's equations of motion for a point particle in the given external potential, up to small corrections corresponding to radiation damping.
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| 2. |
- Jonsson, B. Lars G., et al.
(författare)
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Long time motion of NLS solitary waves in a confining potential
- 2006
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Ingår i: Annales de l'Institute Henri Poincare. Physique theorique. - : Springer Science and Business Media LLC. - 1424-0637 .- 1424-0661. ; 7:4, s. 621-660
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Tidskriftsartikel (refereegranskat)abstract
- We study the motion of solitary-wave solutions of a family of focusing generalized nonlinear Schrodinger equations with a confining, slowly varying external potential, V(x). A Lyapunov-Schmidt decomposition of the solution combined with energy estimates allows us to control the motion of the solitary wave over a long, but finite, time interval. We show that the center of mass of the solitary wave follows a trajectory close to that of a Newtonian point particle in the external potential V(x) over a long time interval.
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| 6. |
- Lindqvist, Ulla, et al.
(författare)
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[11C]Hyaluronan uptake with positron emission tomography in liver disease
- 2000
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Ingår i: European Journal of Clinical Investigation. - : Wiley. - 0014-2972 .- 1365-2362. ; 30:7, s. 600-607
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- BackgroundA hyaluronan-loading test has been developed for assessment of hyaluronan kinetics and applied in patients with liver and joint diseases. This test describes the metabolic process of hyaluronan but cannot define the specific contribution of different organs. A method for labelling of hyaluronan with the short-lived positron-emitting radionuclide 11C has been published and in this study applied in healthy subjects and liver diseases.Materials and methodsPositron emission tomography (PET) was used for the regional assessment and quantification of [11C]hyaluronan uptake in three healthy subjects, four patients with alcoholic liver cirrhosis, one with alcoholic hepatitis and one with liver steatosis. After intravenous administration of 60 MBq of 11C-labelled hyaluronan, a 55-min PET scan was performed over the liver and plasma radioactivity was analysed. Rate constants describing the transport of the [11C]hyaluronan tracer from plasma to the liver were calculated.ResultsHigh uptake was observed in the liver combined with a rapid elimination of tracer from plasma. The liver uptake rate (k1) was significantly lower in patients (0.018 min−1) than in healthy subjects (0.043 min−1, P = 0.002). The rate constants seem to be related to the severity of the disease as defined by the Child–Pugh score.ConclusionsThe study suggests that PET with [11C]hyaluronan could be an accurate method by which to assess liver dysfunction, in conditions where endothelial cell function is impaired. The possibility of quantification over extended portions of the body also opens up possibilities to explore regional differences in liver function and to assess other elimination routes of hyaluronan.
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