[PECULIARITIES OF TREATMENT OF DISTRIBUTED FORMS OF THORACIC PART OF ESOPHAGEAL CANCER].

The aim of this study is to evaluate the methods of treatment of thoracic part of esophageal cancer and to predict the results of treatment depending on the factors of the prognosis. The results of treatment of 366 patients with cancer of the thoracic part of esophagus for 10 years (2007-2016) on the basis of the department of thoracic oncology of the Karaganda oncological dispensary were studied. The overall five-year survival rate, regardless of the method of treatment, was only 8.72% (28 of 321), and in the 6-10 year period 8.41% (27 of 321) lived, p <0.05. Analysis of the overall survival of patients with cancer of the thoracic part of esophagus showed that the method of treatment does not have a significant effect on life expectancy. A multivariate analysis of 19 grades that affect the prognosis of the disease was carried out. Radical type of treatment of the middle and lower thoracic esophagus is surgical, in which the median of cumulative survival is 19 months. Traditional radiotherapy should be used in a limited way, as it is palliative, with a median survival of no more than 9 months. The leading factor in the prognosis for thoracic part of esophageal cancer is the presence of regional metastases, on which the choice of method of treatment depends.

Tunable beam steering enabled by graphene metamaterials.

We demonstrate tunable mid-infrared (MIR) beam steering devices based on multilayer graphene-dielectric metamaterials. The effective refractive index of such metamaterials can be manipulated by changing the chemical potential of each graphene layer. This can arbitrarily tailor the spatial distribution of the phase of the transmitted beam, providing mechanisms for active beam steering. Three different beam steerer (BS) designs are discussed: a graded-index (GRIN) graphene-based metamaterial block, an array of metallic waveguides filled with graphene-dielectric metamaterial and an array of planar waveguides created in a graphene-dielectric metamaterial block with a specific spatial profile of graphene sheets doping. The performances of the BSs are numerically analyzed, showing the tunability of the proposed designs for a wide range of output angles (up to approximately 70°). The proposed graphene-based tunable beam steering can be used in tunable transmitter/receiver modules for infrared imaging and sensing.

Exploiting the dispersion of the double-negative-index fishnet metamaterial to create a broadband low-profile metallic lens.

Metamaterial lenses with close values of permittivity and permeability usually display low reflection losses at the expense of narrow single frequency operation. Here, a broadband low-profile lens is designed by exploiting the dispersion of a fishnet metamaterial together with the zoning technique. The lens operates in a broadband regime from 54 GHz to 58 GHz, representing a fractional bandwidth ~7%, and outperforms Silicon lenses between 54 and 55.5 GHz. This broadband operation is demonstrated by a systematic analysis comprising Huygens-Fresnel analytical method, full-wave numerical simulations and experimental measurements at millimeter waves. For demonstrative purposes, a detailed study of the lens operation at two frequencies is done for the most important lens parameters (focal length, depth of focus, resolution, radiation diagram). Experimental results demonstrate diffraction-limited ~0.5λ transverse resolution, in agreement with analytical and numerical calculations. In a lens antenna configuration, a directivity as high as 16.6 dBi is achieved. The different focal lengths implemented into a single lens could be potentially used for realizing the front end of a non-mechanical zoom millimeter-wave imaging system.

Multi-criteria optimisation problems for chemical engineering systems and algorithms for their solution based on fuzzy mathematical methods.

Mathematical equations for the multi-criteria task of the optimisation of chemical engineering systems, for example for the optimisation of working regimes for industrial installations for benzene production, have been formulated and developed, and based on fuzzy mathematical methods, algorithms for their solution have been developed. Since the chemical engineering system, which is being researched, is characterised by multiple criteria and often functions in conditions of uncertainty, the presenting problem is formulated in the form of multi-criteria equations for fuzzy mathematical programming. New mathematical formulations for the problems being solved in a fuzzy environment and heuristic algorithms for their solution have been developed by the modification of various optimisation principles based on fuzzy mathematical methods.