Plasmonic rod dimers as elementary planar chiral meta-atoms

Electromagnetic response of metallic rod dimers is theoretically calculated for arbitrary planar arrangement of rods in the dimer. It is shown that dimers without an in-plane symmetry axis exhibit elliptical dichroism and act as "atoms" in planar chiral metamaterials. Due to a very simple geometry of the rod dimer, such planar metamaterials are much easier in fabrication than conventional split-ring or gammadion-type structures, and lend themselves to a simple analytical treatment based on coupled dipole model. Dependencies of metamaterial's directional asymmetry on the dimer's geometry are established analytically and confirmed in numerical simulations.Comment: 3 page

Racah coefficients and extended HOMFLY polynomials for all 5-, 6- and 7-strand braids

Basing on evaluation of the Racah coefficients for SU_q(3) (which supported the earlier conjecture of their universal form) we derive explicit formulas for all the 5-, 6- and 7-strand Wilson averages in the fundamental representation of arbitrary SU(N) group (the HOMFLY polynomials). As an application, we list the answers for all 5-strand knots with 9 crossings. In fact, the 7-strand formulas are sufficient to reproduce all the HOMFLY polynomials from the katlas.org: they are all described at once by a simple explicit formula with a very transparent structure. Moreover, would the formulas for the relevant SU_q(3) Racah coefficients remain true for all other quantum groups, the paper provides a complete description of the fundamental HOMFLY polynomials for all braids with any number of strands.Comment: 16 pages + Tables and Appendice

Plasmonic nanoparticle monomers and dimers: From nano-antennas to chiral metamaterials

We review the basic physics behind light interaction with plasmonic nanoparticles. The theoretical foundations of light scattering on one metallic particle (a plasmonic monomer) and two interacting particles (a plasmonic dimer) are systematically investigated. Expressions for effective particle susceptibility (polarizability) are derived, and applications of these results to plasmonic nanoantennas are outlined. In the long-wavelength limit, the effective macroscopic parameters of an array of plasmonic dimers are calculated. These parameters are attributable to an effective medium corresponding to a dilute arrangement of nanoparticles, i.e., a metamaterial where plasmonic monomers or dimers have the function of "meta-atoms". It is shown that planar dimers consisting of rod-like particles generally possess elliptical dichroism and function as atoms for planar chiral metamaterials. The fabricational simplicity of the proposed rod-dimer geometry can be used in the design of more cost-effective chiral metamaterials in the optical domain.Comment: submitted to Appl. Phys.

Neuroimmunoendocrinal markers of prediction of preeclampsia

Objective: to establish the features of neuroendocrine regulation of homeostasis and the immune system of a woman in the 1 st trimester of pregnancy complicated by preeclampsia, and to establish prognostic criteria for the occurrence of this obstetric complication. Materials and methods. A dynamic observation of the course of pregnancy, childbirth and the postpartum period was carried out in women pregnant for the fist time from the early stages of gestation (7–8 weeks); of these, 46 women were selected for whom the pregnancy was complicated by preeclampsia and who formed the following clinical groups: the 1 st group – 32 pregnant women with mild preeclampsia; the 2nd group – 14 pregnant women with severe preeclampsia. The control group – 48 somatically healthy pregnant women with the physiological course of pregnancy. In the serum of pregnant clinical observation groups in the 1 st (10–14 weeks), in the 2nd (23–26 weeks) and in the 3rd trimesters (32–35 weeks), the concentration of adrenocorticotropic hormone, β-endorphin was determined by ELISA , cortisol, insulin, placental lactogen, human chorionic gonadotropin, α-fetoprotein; the concentration of lymphocytes and markers of their activation (CD3, CD4, CD8, CD14, CD16, CD19, CD25, CD71, CD95, HLA DR) was determined by the immunoflorescence method using monoclonal antibodies. Results. For the women with the preeclampsia of the 1 st degree the neuroendocrinal regulation of homeostasis is broken in the 1 st trimester of pregnancy with creation of primary placental insuffiency, oppression of the stress-realizing function of the hypothalamo-pituitary system, development of insulin resistance, that as a whole testifis about dysadaptation of an organism of the women in the 1 st trimester of pregnancy. In the 1 st trimester the state of the fetoplacental complex for the pregnant women with preeclampsia, regardless of the degree of severity, is characterized by the dysbalance of hormones production, which testifis to development of primary placental insuffiency. Conclusions. For the women with preeclampsia of mild degree dysbalance of the immune system develops already in the 1 st trimester of pregnancy as relative augmentation of total of T-lymphocytes with simultaneous decrease of their functional activity, particularly Т-helpers of the 2nd type, which is accompanied by the decrease of anti-inflmmatory cytokines production. For the women with preeclampsia of serious degree the quantitative parameters of non-specifi and cellular immunity (CD3, CD4, CD8, CD16, HLA-DR) are reduced already in 1 st trimester of pregnancy with simultaneous rising of the value of immunoregulatory index (CD4/CD8) and functional activity of Т-helpers of the 1 st type on the background of the activity oppression of the 2nd type Т-helpers

Surface polaritons at the interface of gyrotropic and nonlinear isotropic media

Surface polaritons at the interface of gyrotropic and non-linear isotropic media are investigated. Dispersion equation and existence conditions for TE surface polariton modes are obtained

Surface polaritons in symmetry planes of biaxial crystals

An integral approach is presented in the theory of surface electromagnetic waves propagating along the plane interface of bianisotropic non-absorbing media including optically active gyrotropic and bigyrotropic ones. This approach gives a uniform way of obtaining the dispersion equation for surface polaritons for an arbitrary cut section of the bianisotropic crystals and allows us to establish the existence conditions of surface polaritons. An example of application of this approach for the boundary of bianisotropic and isotropic media is given