Determination of zinc complexation with an immobilized reagent for the analysis of environmental objects.

Although significant progress has been made in the effective measurement of Zn(II), Аlizarin red S (ARS) was immobilized on polyethylene polyamine-modified polyacrylonitrile (PPF-1) via a new matrix. This approach allows the detection of low levels of Zn(II) ions in various water samples via preconcentrated atomic absorption spectrometry. The use of PPF-1 in a polymer matrix for zinc preconcentration presents several advantages over traditional sorbtion-spectroscopic methods, including reduced cost, high zinc recovery, increased sensitivity, and selectivity.

Quantitative Structure-Permittivity Relationship Study of a Series of Polymers.

Dielectric constant is an important property which is widely utilized in many scientific fields and characterizes the degree of polarization of substances under the external electric field. In this work, a structure-property relationship of the dielectric constants (ε) for a diverse set of polymers was investigated. A transparent mechanistic model was developed with the application of a machine learning approach that combines genetic algorithm and multiple linear regression analysis, to obtain a mechanistically explainable and transparent model.

Stability Constant and Potentiometric Sensitivity of Heavy Metal-Organic Fluorescent Compound Complexes: QSPR Models for Prediction and Design of Novel Coumarin-like Ligands.

Industrial wastewater often consists of toxic chemicals and pollutants, which are extremely harmful to the environment. Heavy metals are toxic chemicals and considered one of the major hazards to the aquatic ecosystem. Analytical techniques, such as potentiometric methods, are some of the methods to detect heavy metals in wastewaters.

[The biological rhythms of cardiac activity based on cardiointervalography in children with rheumatism during readaptation after sanatorium treatment].

Heart rate as an integral characteristic of systemic condition in rheumatism was studied in 11-13-year-old children with rheumatic heart disease. The children achieved remission by clinical and laboratory tests and were experiencing postsanatorium readaptation. Pretreatment amplitude of the fluctuations from the mean circadian values were reduced in the patients compared to healthy controls.