National Academy of Sciences of Ukraine

About: National Academy of Sciences of Ukraine is a government organization based out in Kyiv, Ukraine. It is known for research contribution in the topics: Adsorption & Magnetic field. The organization has 46422 authors who have published 59466 publications receiving 573466 citations. The organization is also known as: Natsional’na akademiya nauk Ukrayiny & NAN Ukraine.

Validity assessment of the symptom checklist SCL-90-R and shortened versions for the general population in Ukraine

Abstract: The Symptom Checklist-90-Revised (SCL-90-R) is a widely used symptomatic distress questionnaire. A translated version of the SCL-90-R has been applied in Ukrainian general population surveys several times but has not yet been validated in this country. The SCL-90-R and its short versions (BSI-53, SCL-27, BSI-18, SCL-14 and SCL-9-K) were investigated in order to comparatively assess their properties and applications in Ukraine. Secondary analysis of three nationally representative cross-sectional surveys (1997, 1999 and 2014) using SCL-90-R was applied. Two thousand sixty nine respondents participated in 2014; the sample size for the 1997 and 1999 surveys was 1810 respondents per wave. Statistical data analysis is based on calculating internal consistencies with Cronbach’s Alpha, confirmatory factor analysis, nonparametric correlations and effect sizes for the equivalence of the full and short versions. The scales of SCL-90-R and its shortened versions showed equally high internal consistencies. With regard to factorial validity, 2014 data confirmed the dimensional structure of all versions. Unsatisfactory results were found in 1997 and 1999 for SCL-90-R and in 1997 for SCL-27, based on the Chi-square criterion (χ2/degrees of freedom > 5), though other indexes suggested satisfactory model fit (RMSEA 0.95). Analysis of the equivalence of shortened and full versions of the SCL-90-R has shown the presence of small effect sizes. BSI-18 and SCL-9-K are recommended for use in general population surveys as more economical versions of SCL-90-R. Both versions revealed satisfactory validity in 1997, 1999 and 2014.

Topological entropy of nonautonomous piecewise monotone dynamical systems on the interval

Abstract: The topological entropy of a nonautonomous dynamical system given by a sequence of compact metric spaces (X i) ∞ i=1 and a sequence of continuous maps (f i) ∞ i=1 , f i : X i → X i+1 , is defined. If all the spaces are compact real intervals and all the maps are piecewise monotone then, under some additional assumptions, a formula for the entropy of the system is obtained in terms of the number of pieces of monotonicity of fn •. .. • f 2 • f 1. As an application we construct a large class of smooth triangular maps of the square of type 2 ∞ and positive topological entropy.

The Symbiotic Relationship Between Drug Discovery and Organic Chemistry.

Abstract: All pharmaceutical products contain organic molecules; the source may be a natural product or a fully synthetic molecule, or a combination of both. Thus, it follows that organic chemistry underpins both existing and upcoming pharmaceutical products. The reverse relationship has also affected organic synthesis, changing its landscape towards increasingly complex targets. This Review article sets out to give a concise appraisal of this symbiotic relationship between organic chemistry and drug discovery, along with a discussion of the design concepts and highlighting key milestones along the journey. In particular, criteria for a high-quality compound library design enabling efficient virtual navigation of chemical space, as well as rise and fall of concepts for its synthetic exploration (such as combinatorial chemistry; diversity-, biology-, lead-, or fragment-oriented syntheses; and DNA-encoded libraries) are critically surveyed.

SYNTHESIS OF ALLOY Ti − 6Al − 4V WITH LOW RESIDUAL POROSITY BY A POWDER METALLURGY METHOD

Abstract: The possibility of producing titanium alloy Ti ― 6Al ― 4V with minimal residual porosity from mixtures of elemental powders by the method of pressing and sintering without hot deformation during or after sintering was investigated. Various powder mixtures based on titanium and titanium hydride with alloying additions of either elemental powders having different particle sizes, or master alloys, were studied. It was shown that the synthesis of Ti ― 6Al ― 4V from mixtures of titanium hydride and master alloys is optimal with respect to the attainment of high relative density. In this case the sintered material has density up to 99%, homogeneous microstructure with relatively small (100-120 μm) β-phase grains, and a low concentration of impurities, in particular oxygen, which provide a high level of mechanical properties σ(ten = 970 MPa, δ = 6%).