658 research outputs found
Generalized Kadomtsev-Petviashvili equation with an infinite dimensional symmetry algebra
A generalized Kadomtsev-Petviashvili equation, describing water waves in
oceans of varying depth, density and vorticity is discussed. A priori, it
involves 9 arbitrary functions of one, or two variables. The conditions are
determined under which the equation allows an infinite dimensional symmetry
algebra. This algebra can involve up to three arbitrary functions of time. It
depends on precisely three such functions if and only if it is completely
integrable.Comment: AMSLaTeX, 16 pages, no figures, corrected some typos and added two
new section
Heisenberg-type higher order symmetries of superintegrable systems separable in cartesian coordinates
Heisenberg-type higher order symmetries are studied for both classical and
quantum mechanical systems separable in cartesian coordinates. A few particular
cases of this type of superintegrable systems were already considered in the
literature, but here they are characterized in full generality together with
their integrability properties. Some of these systems are defined only in a
region of , and in general they do not include bounded solutions.
The quantum symmetries and potentials are shown to reduce to their
superintegrable classical analogs in the limit.Comment: 23 Pages, 3 figures, To appear in Nonlinearit
Forging a potent vaccine adjuvant: CpG ODN/cationic peptide nanorings
Cataloged from PDF version of article.Type I interferon inducers may potentially be engineered to function as antiviral and anticancer agents, or alternatively, vaccine adjuvants, all of which may have clinical applications. We recently described a simple strategy to convert a Toll-like receptor 9 (TLR9) agonist devoid of interferon alpha (IFN alpha) stimulating activity into a robust Type I interferon inducer with potent vaccine adjuvant activity
Phenotypic Type 2 Diabetes in Obese Youth: Insulin Sensitivity and Secretion in Islet Cell Antibody–Negative Versus –Positive Patients
OBJECTIVE— Some obese youth with a clinical diagnosis of type 2 diabetes have evidence of islet cell autoimmunity with positive autoantibodies. In this study, we investigated the differences in insulin sensitivity and secretion between autoantibody-negative (Ab−) and -positive (Ab+) youth with clinically diagnosed type 2 diabetes in comparison with control subjects
Islet Cell Antibody–Positive Versus –Negative Phenotypic Type 2 Diabetes in Youth: Does the oral glucose tolerance test distinguish between the two?
Synthesis of a hexafluoropropylidene-bis(phthalic anhydride)-based polyimide and its conducting polymer composites with polypyrrole
A new electrically conducting composite film from polypyrrole and 4,4′(hexafluoroisopropylidene)-bis(phthalic anhydride)-based polyimide was prepared. Pyrrole and the dopant ion can easily penetrate through the polyimide substrate and electropolymerize on the platinum (Pt) electrode due to the swelling of the polyimide on the metal electrode. The electrochemical properties of polypyrrole-polyimide (PPy/PI ) composite films have been investigated by using cyclic voltammetry. The PPy/PI composite film is suitable for use as the electroactive material owing to its stable and controllable electrochemical properties. The electrical conductivity of composites falls in the range 0.0035-15 S/cm. Scanning electron micrograph, FTIR, and thermal studies indicate that PPy and PI form a homogeneous material rather than a simple mixture. © 1997 John Wiley & Sons, Inc
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