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We discuss the applicability of the Angular Overlap Model (AOM) to evaluate the electronic structure of lanthanide compounds, which are currently the subject of incredible interest in the field of luminescent materials. The functioning of phosphors is well established by the f–d transitions, which requires the investigation of both the ground 4fn and excited 4fn−15d1 electron configurations of the lanthanides. The computational approach to the problem is based on the effective Hamiltonian adjusted from ligand field theory, but not restricted to it. The AOM parameterization implies the chemical bonding concept. Focusing our interest on this interaction, we take the advantages offered by modern computational tools to extract AOM parameters, which ensure the transparency of the theoretical determination and convey chemical intuitiveness of the non-empirical results. The given model contributes to the understanding of lanthanides in modern phosphors with high or low site symmetry and presents a non-empirical approach using a less sophisticated computational procedure for the rather complex problem of the ligand field of both 4f and 5d open shells.

Introduction. A brief review of scientific publications relating to questions of the object for study modeling that implements the EIT methods is given. Formulation of the problem. EIT features associated with three-dimensionality of processes taking place in the study objects during the measurement and the complexity of the reconstruction process are shown. A comparative analysis of the quasi-static and full-wave model of the object for study is presented. Conclusion. Based on three-dimensional processes that take place in the study objects using EIT has shown that adequate models of study objects should be based on quasi-static or full-wave electrodynamics approaches., Выполнен обзор научных работ, касающихся вопросов моделирования исследуемых объектов в электроипедансной томографии. С учетом трехмерности процессов, происходящих в исследуемых объектах при использовании электроимпедансных томографов, показано, что для адекватного моделирования объектов исследования необходимо применять квазистатический или полнополевой электродинамические подходы., Зроблено огляд наукових праць, що стосуються питань моделювання досліджуваних об‘єктів у разі електроімпедансної томографії. Спираючись на тривимірність процесів, які відбуваються в об‘єктах дослідження при застосуванні електроімпедансних томографів, показано, що для адекватного моделювання об‘єктів дослідження необхідно застосовувати квазістатичний або повнопольовий електродинамічні підходи.

Зроблено огляд наукових праць, що стосуються питань моделювання досліджуваних об‘єктів у разі електроімпедансної томографії. Спираючись на тривимірність процесів, які відбуваються в об‘єктах дослідження при застосуванні електроімпедансних томографів, показано, що для адекватного моделювання об‘єктів дослідження необхідно застосовувати квазістатичний або повнопольовий електродинамічні підходи.

Presented here is a quantitative model of the wrapping and unwrapping of the DNA around the histone core of the nucleosome that suggests a mechanism by which this transition can be controlled: alteration of the charge state of the globular histone core. The mechanism is relevant to several classes of posttranslational modifications such as histone acetylation and phosphorylation; several specific scenarios consistent with recent in vivo experiments are considered. The model integrates a description based on an idealized geometry with one based on the atomistic structure of the nucleosome, and the model consistently accounts for both the electrostatic and nonelectrostatic contributions to the nucleosome free energy. Under physiological conditions, isolated nucleosomes are predicted to be very stable (38 +/- 7 kcal/mol). However, a decrease in the charge of the globular histone core by one unit charge, for example due to acetylation of a single lysine residue, can lead to a significant decrease in the strength of association with its DNA. In contrast to the globular histone core, comparable changes in the charge state of the histone tail regions have relatively little effect on the nucleosome's stability. The combination of high stability and sensitivity explains how the nucleosome is able to satisfy the seemingly contradictory requirements for thermodynamic stability while allowing quick access to its DNA informational content when needed by specific cellular processes such as transcription.

Presented here is a quantitative model of the wrapping and unwrapping of the DNA around the histone core of the nucleosome that suggests a mechanism by which this transition can be controlled: alteration of the charge state of the globular histone core. The mechanism is relevant to several classes of posttranslational modifications such as histone acetylation and phosphorylation; several specific scenarios consistent with recent in vivo experiments are considered. The model integrates a description based on an idealized geometry with one based on the atomistic structure of the nucleosome, and the model consistently accounts for both the electrostatic and nonelectrostatic contributions to the nucleosome free energy. Under physiological conditions, isolated nucleosomes are predicted to be very stable (38 +/- 7 kcal/mol). However, a decrease in the charge of the globular histone core by one unit charge, for example due to acetylation of a single lysine residue, can lead to a significant decrease in the strength of association with its DNA. In contrast to the globular histone core, comparable changes in the charge state of the histone tail regions have relatively little effect on the nucleosome's stability. The combination of high stability and sensitivity explains how the nucleosome is able to satisfy the seemingly contradictory requirements for thermodynamic stability while allowing quick access to its DNA informational content when needed by specific cellular processes such as transcription.

Presented here is a quantitative model of the wrapping and unwrapping of the DNA around the histone core of the nucleosome that suggests a mechanism by which this transition can be controlled: alteration of the charge state of the globular histone core. The mechanism is relevant to several classes of posttranslational modifications such as histone acetylation and phosphorylation; several specific scenarios consistent with recent in vivo experiments are considered. The model integrates a description based on an idealized geometry with one based on the atomistic structure of the nucleosome, and the model consistently accounts for both the electrostatic and nonelectrostatic contributions to the nucleosome free energy. Under physiological conditions, isolated nucleosomes are predicted to be very stable (38 +/- 7 kcal/mol). However, a decrease in the charge of the globular histone core by one unit charge, for example due to acetylation of a single lysine residue, can lead to a significant decrease in the strength of association with its DNA. In contrast to the globular histone core, comparable changes in the charge state of the histone tail regions have relatively little effect on the nucleosome's stability. The combination of high stability and sensitivity explains how the nucleosome is able to satisfy the seemingly contradictory requirements for thermodynamic stability while allowing quick access to its DNA informational content when needed by specific cellular processes such as transcription.

The structural feature of applicators is examined for hyperthermia that possibility of calculation of the electromagnetic fields and division of temperature in біотканинах at treatment of hyperplasia of peredmikhurovoy gland., Рассматривается конструктивная особенность аппликаторов для гипертермии возможность расчета электромагнитных полей и распределение температуры в биотканях при лечении гиперплазии предстательной железы., Розглядається конструктивна особливість аплікаторів для гіпертермії та можливість розрахунку електромагнітних полів і розподіл температури в біотканинах при лікуванні гіперплазії передміхурової залози.

Розглядається конструктивна особливість аплікаторів для гіпертермії та можливість розрахунку електромагнітних полів і розподіл температури в біотканинах при лікуванні гіперплазії передміхурової залози.