Lipid peroxidation of the erythrocyte membrane caused by stimulated polymorphonuclear leukocytes in the presence of ferritin

Lipid peroxidation of erythrocyte membrane was caused by phorbol myristate acetate (PMA)-stimulated polymorphonuclear leukocytes (PMN) in the presence of ferritin. PMN themselves were not peroxidized. A lag period was observed before the start of the peroxidation reaction. In contrast, ferritin iron was continuously released by PMA-stimulated PMN, suggesting that accumulation of free iron in the reaction system was important for proceeding of the peroxidation reaction. Superoxide dismutase, catalase, hydroxyl radical scavengers and an iron chelator, diethylenetriaminepenta-acetic acid, inhibited the lipid peroxidation, indicating that the lipid peroxidation is initiated by a hydroxyl radical generated from the interaction of H2O2 with ferrous iron released from ferritin.     

Free boson realization of

We construct a realization of the quantum affine algebra of an arbitrary level k in terms of free boson fields. In the q1 limit this realization becomes the Wakimoto realization of. The screening currents and the vertex operators (primary fields) are also constructed; the former commutes with modulo total difference, and the latter creates the highest weight state from the vacuum state of the boson Fock space.fellow of Soryushi ShogakukaiAddress after June 1: Department of Physics, Faculty of Liberal Arts, Shinshu University, Matsumoto 390, Japan     

Lattice dynamics of calcium oxide

The effect of the electronic extension on the electrostatic potential was first taken into account functionally by Birman. We have applied his model to the lattice dynamics of CaO, where the degree of the electronic extension w was defined and determined with the use of the electronic charge density distribution obtained from analysis of X-ray data. Our treatment shown here not only gives a physically meaningful model including the feature of the electronic extension, but also involves essentially the same very simple process as the conventional point-charge model but with fewer adjustable parameters. Good reproduction of calculated phonon dispersion curves was obtained by taking into account the electronic extension, although the degree of the electronic extension, w, used to fit the curve was a little larger than that derived from the observed data owing to the first rough approximation for the potential energy arising from the electronic extension.     

Frequency dependent Shubnikov-De Haas oscillations in Si-MOS-FET under high magnetic fields

The quantum oscillations in the AC magnetoconductance was studied for inversion layers in Si-MOS-FETs under high magnetic fields at 1.5 K. Each peak in the Shubnikov-de Haas oscillation was found to be remarkably sharpened with increasing frequency up to 50 MHz. It was also found that the width of the gate voltage for non-conductive region (σ_xx=0) increases with increasing frequency.     

Pair breaking parameter of two-dimensional dirty superconductors

Intrinsic mechanism of pair breaking is given for dirty superconducting films. Dynamical interaction between electrons such as Coulomb interaction plays an essential role. The diffusion processes of both density- and pair-fluctuations are also important. The problem of the Thompson's parameter for the Maki term of fluctuation conductivity is solved and the correct dependence of the parameter of the sheet resistance R_sq is given.     

Total Valuation Rings of Ore Extensions

We consider extensions of a total valuation ring V of a skew field K to the Ore extension K(X;σ, δ) for an endomorphism σ of K and a σ-derivation δ. It is shown that there exists an extension R of V with X ∈ R, such that ${\overline X}$ is transcendental over V/J(V) if and only if (σ,δ) is compatible with V, where ${\overline X} = X + J(R^(1))$ . In the case V is invariant, it is established that there is an invariant extension R of V in K(X;σ,δ) such that ${\overline X}$ is transcendental if and only if σ(a)V = aV and δ(a) ∈ aV for all a ∈ K.     

Hyers–Ulam stability of linear differential operator with constant coefficients

Let P(z) be a polynomial of degree n with complex coefficients and consider the n–th order linear differential operator P(D). We show that the equation P(D)f = 0 has the Hyers–Ulam stability, if and only if the equation P(z) = 0 has no pure imaginary solution. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Raman probe using a single hollow waveguide

A simple Raman probe was realized using a single flexible hollow waveguide (HW). A HW coated with a silver film, which had reasonable transmission and little optical background noise, was used as a bidirectional transmission fiber for both the excitation and collection of Raman scattered light. The HW itself generated no Raman scattering or fluorescence noise during transmission. A complex filtering system at the end of the waveguide was thus unnecessary. In addition, the measured Raman spectra showed better signal-to-noise ratios than a conventional Raman fiber probe. The HW's suitability as a Raman fiber probe was also demonstrated.