Novel relativistic plasma excitations in a gated two-dimensional electron system.

The microwave response of a two-dimensional electron system (2DES) covered by a conducting top gate is investigated in the relativistic regime for which the 2D conductivity σ_{2D}>c/2π. Weakly damped plasma waves are excited in the gated region of the 2DES. The frequency and amplitude of the resulting plasma excitations show a very unusual dependence on the magnetic field, conductivity, gate geometry, and separation from the 2DES. We show that such relativistic plasmons survive for temperatures up to 300 K, allowing for new room-temperature microwave and terahertz applications.

Magneto-optical response of 3d-decorated polyoxomolybdates with ε-Keggin structure.

A family of virtually isostructural tetra-capped ε-Keggin-type polyoxomolybdate(V) cluster compounds, [Mo12(V)O28(µ(2)­OH)10(µ(3)­OH)2{M(II)(H2O)3}4]·nH2O ({M4(II)Mo12(V)}, M = Ni, Co), exhibits magnetic-field-dependent optical response in their electronic absorption spectra in the 0­33 T range. On the basis of Effective Hamiltonian Crystal Field calculations, we find that the observed field-induced decrease in reflectance of these compounds can be related to the formally spin-forbidden on-site d­d excitations. We tentatively position the observed effect among other known magneto-optical effects and predict that similar features may be found for other {M49(II)Mo12(V)} analogues.

[Development of immunopathology in patients with yersinia infection].

AIM: To evaluate clinical significance of changes in IL-6 concentration and neopterin in peripheral blood of patients for prognosis of the course and outcome of yersinia infection (YI). MATERIAL AND METHODS: Clinical examination and laboratory tests, 1-5-year follow-up were conducted in 68 patients with a cyclic, recurrent and lingering course of the disease. IL-6 and neopterin concentrations were measured in the course of the disease. RESULTS: Dynamic control over IL-6 concentrations in the blood of patients with yersinia infection provides information predicting the disease course and prognosis. Blood concentrations of neopterin are of help in prognostication of long-term outcomes of acute infection. CONCLUSION: Pathological syndromes forming in acute stage of yersinia infection are related to interleukin-dependent immunopathology.