On the degeneracy of <Emphasis Type="Italic">SU</Emphasis>(3)<Subscript><Emphasis Type="Italic">k</Emphasis></Subscript> topological phases

The ground state degeneracy of an SU(N) _k topological phase with n quasiparticle excitations is a relevant quantity for quantum computation, condensed matter physics, and knot theory. It is an open question to find a closed formula for this degeneracy for any N >2. Here we present the problem in an explicit combinatorial way and analyze the case N = 3. While not finding a complete closed-form solution, we obtain generating functions and solve some special cases.     

Quantum Group Approach to q-Special Functions

Quantum groups are used to define q-special functions. The Casimir operatorsof a variation of SU _q(2) and E _q(2) are derived. The proposed q-associated Legendreand q-Bessel functions are the eigenfunctions of the Casimirs. The results differfrom ordinary q-special functions, but this is expected since the q-generalizationis not unique.     

Determination of cobalt by catalytic-adsorptive differential pulse voltammetry in the presence of 2-aminocyclopentene-1-dithiocarboxylic acid and nitrite

A novel method for the determination of cobalt(II) by stripping voltammetry is described. It involves an adsorptive accumulation of the cobalt(II)-2-aminocyclopentene-1-dithiocarboxylic acid complex on a hanging mercury drop electrode, followed by a stripping voltammetric measurement of the catalytic reduction current of the complex at –1.4 V at pH = 9 (vs. Ag/AgCl). The effects of various experimental parameters on the catalytic current were investigated. An accumulation time of 60 s results in a low experimental limit of detection of 0.1 ng/mL of Co(II), and 0.50 to 40.0 ng/mL of cobalt can be determined. The relative standard deviation at 0.50 ng/mL is 2.8%. Possible interferences from co-existing ions were also investigated. Received: 17 August 1998 / Revised: 16 November 1998 / Accepted: 20 November 1998     

Star Product and q-Deformation of Grassmann and Symmetric Algebras

We review the relation between the star producton a Poisson-Lie group and the quantum Yang-Baxterequation. We define the q-deformed Grassmann andq-deformed symmetric algebras on a vector space V, and prove that a star product on a triangular(simple quasitriangular) Poisson-Lie group G determinesa q-deformation of both the symmetric and Grassmannalgebras over a dual of a g-module where g is thecorresponding triangular (simple quasitriangular) Liebialgebra of the Poisson-Lie group G.     

Randomized Entangled Mixed States from Phase States

We construct randomized entangled mixed states by using the formalism of phase states for d-dimensional systems (qudits). The randomized entangled mixed states are a special kind of mixed states that exhibit genuine multipartite correlation. Such states are obtained by the application of randomized entangling operators to an arbitrary pair of qudits of a multiqudit system. The study of the entanglement of randomized mixed states is of great importance in quantum computation since any experimental implementation of entangled states in a realistic environment can be made by imperfect entangling gates. We give a brief review of some necessary background about unitary phase operators and phase states of a multi-qudit system. Evolved density matrices arise when qudits of the multi-qudit system interact via a Hamiltonian of Heisenberg type. The randomized entangled states associated with evolved density matrices are derived via the action of an entangling operator on a pair of two qudits {i, j} of the multi-qudit system with some probability p. The randomized entangled mixed states for bipartite, tripartite and multipartite systems are explicitly expressed and their Kraus decomposition properties are discussed.

     

Gastroprotective Effect of Microencapsulated Myrtus communis Essential Oil against Ethanol/HCl-Induced Acute Gastric Lesions

Myrtus communis L. essential oil (EO), mainly composed of myrtenyl acetate (30.6%), linalool (14.9%), α-pinene (11.10%) and 1,8-cineole or eucalyptol (9.9%), was microencapsulated with maltodextrin by emulsification and spray-drying, reaching a yield and efficiency of 43.7 and 48.7%, respectively. The microencapsulated myrtle EO (MMEO) was then evaluated regarding its gastroprotective activity in a model of ethanol/HCl-induced acute gastric ulcer in Wistar rats. Pretreatment with MMEO induced a remarkable inhibition of gastric lesions and acidity, correlated to high healing and protection percentages. Moreover, it exerted a potent anti-inflammatory effect on the gastric mucosa, counteracting EtOH-induced gastric lipoperoxidation and preventing the depletion of the antioxidant enzyme activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Taken together, the gastroprotective action of encapsulated MMEO may be multi-factorial, and ascribable, at least in parts, to its anti-inflammatory and antioxidant properties.