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Aims: To investigate retrobulbar circulatory parameters in type 2 diabetic patients with and without diabetic retinopathy (DR) progression. Methods: This was a prospective cohort study. One eye of 35 diabetic [...]

Considering the special value of the tellurates and their use for preparation of superconducting materials, their synthesis and study are of great importance for both science and industry. The compounds Li2H4TeO6 and Na2H4TeO6 were synthesised. Chemical, X-ray diffraction and derivatographic analyses were made to prove the purity of the substances obtained. Besides, the crystals of the metatellurates of lithium and sodium were obtained and separated. Their individuality and purity were proved by chemical and X-ray diffraction. The meta- and orthotellurates were subjected to derivatographic analysis through which the mechanism of their thermal decomposition was determined. [ABSTRACT FROM AUTHOR]

Competitiveness is a fundamental indicator of great importance for the functioning of both enterprises and national economies. A number of factors influence the assessment of an enterprise's competitiveness. Among these factors is innovation activity. For Bulgaria wine production is a traditional sector with potential for development in different directions. Given the increasing competition on the domestic and world wine market, a research of the Bulgarian wine industry is more than necessary. One of the directions that can contribute to increasing the competitiveness of the sector is increasing the innovation activity of the wine producers. In this sense, the aim of this study is to conceptualize the role of innovation activity as an element of competitiveness, and in particular its role in improving the competitiveness of the wine industry. For this purpose, a number of theoretical sources and empirical studies on innovation activity and competitiveness in both general and wine-making are reviewed. Systematization of the studied literature was made and summaries were made about the possible contribution of the innovation activity in improving the competitiveness of Bulgarian wine production. [ABSTRACT FROM AUTHOR]

The paper presents the results from the determination of the standard enthalpies of the formation of selenites of rare earths elements determined by three methods: method of ionic increments, method of Kapustinski and method of Berkengeim. The precision of the determination was estimated. The relative error was small which indicated for calculation accuracy. The dependences of the standard enthalpies of formation (ΔH2980) on the molecular weights of the compounds was plotted and analysed. The selenites of rare earths elements synthesised and their thermodynamic characteristics are necessary to fill in data about the important branch of inorganic chemistry -- chemistry of selenium. [ABSTRACT FROM AUTHOR]

In the present paper, a regression method for determination of the standard enthalpies of formation of selenites of rare earth elements is suggested. The interpolation formulae of Newton for non-equidistant values of the argument from the computational methods of mathematical analysis were used. For the selected angles of interpolation, the standard enthalpies calculated by the polynomial coincided with the arithmetic average values calculated by three methods: method of ion increments, method of Kapustinski and method of Berkengeim, as it should be. For compounds outside the interpolation angles, the enthalpies were calculated by the interpolation method of Newton. It can be seen that there was a good agreement with the arithmetic average values of these substances. [ABSTRACT FROM AUTHOR]

Tellurites of Li4TeO4, K2TeO3 and K2Te4O9 are synthesised and their specific molar heat capacities are experimentally determined for the first time. The tellurites discussed in the present paper are used for preparation of optical glasses with special properties for optoelectronics. Another important field of application is in pharmaceutical industry - as components of medications for treatment of hard to treat diseases. The tellurites synthesised are prepared for chemical analysis, differential thermal analysis and X-ray analysis. The use of the tellurites studied is related to knowing their thermodynamic properties like specific molar heat capacity (Cp,m), enthalpy (ΔT′ THm 0), entropy (ΔT′ TSm 0) and Gibbs energy (-ΔT′ TGm 0). The temperature dependences of their molar heat capacities are determined using the least squares method. The thermodynamic properties are calculated: entropy, enthalpy and Gibbs function. [ABSTRACT FROM AUTHOR]

Tellurites of Li4TeO4, K2TeO3 and K2Te4O9 are synthesised and their specific molar heat capacities are experimentally determined for the first time. The tellurites discussed in the present paper are used for preparation of optical glasses with special properties for optoelectronics. Another important field of application is in pharmaceutical industry - as components of medications for treatment of hard to treat diseases. The tellurites synthesised are prepared for chemical analysis, differential thermal analysis and X-ray analysis. The use of the tellurites studied is related to knowing their thermodynamic properties like specific molar heat capacity (Cp,m), enthalpy (ΔT′ THm 0), entropy (ΔT′ TSm 0) and Gibbs energy (-ΔT′ TGm 0). The temperature dependences of their molar heat capacities are determined using the least squares method. The thermodynamic properties are calculated: entropy, enthalpy and Gibbs function. [ABSTRACT FROM AUTHOR]