Determination of the dominant factor affecting the change of the phase transition point in thin ferroelectric films

The study was supported by the Russian Foundation For Basic Research, Project № 19-32-50032

Finsler geometry modeling of reverse piezoelectric effect in PVDF

We apply the Finsler geometry (FG) modeling technique to study the electric field-induced strain in ferroelectric polymers. Polyvinylidene difluoride (PVDF) has a negative longitudinal piezoelectric coefficient, which is unusual in ferroelectrics, and therefore the shape changes in this material are hard to predict. We find that the results of Monte Carlo simulations for the FG model are in good agreement with experimental strain-electric field curves of PVDF-based polymers in both longitudinal and transverse directions. This implies that FG modeling is suitable for reproducing the reverse piezoelectric effect in PVDF

The model of formation of Foreign-Language skills of the students in Self-Learning activities

© 2015, Canadian Center of Science and Education. The article is aimed to develop the model of the formation of foreign-language skills of the students in selflearning activities. The leading approach to the development of this model is the competence approach, reinforcing the role of experience and practical application of knowledge competencies in self-study of foreign language by students. This article presents the following components of the model of formation of foreign-language competencies of students in self-learning activities: goals, objectives, principles, stages of the formation of foreign language competences in self-learning activities, forms, functions, content of self-learning activities, result. The content of this article can be used to improve the process of teaching of foreign language, not only in the higher schools but also in the secondary vocational schools

The principles of selecting and structuring the syllabus of foreign language teaching aimed at developing the students research competence

© 2015, Review of European Studies. All right reserved. The essence of the development of the students research competence in the process of learning a foreign language is to acquire knowledge, skills and work methods allowing students to take the position of a researcher capable both to carry out and present the results of the research in the international language that contributes to unlocking their full intellectual potential in the future professional activity. The methodological basis for solving this problem has become the modular competence-forming, research and integrative approaches. According to these approaches the article discusses the nature and the content of the principles of selection and structuring the syllabus of foreign language teaching aimed at creating the students research competence: the principle of integration, the principle of poly-logic cognition, a problematic principle, the principle of concentrism and the principle of mediation activities by means of learning a foreign language. The article submissions present both theoretical and practical value for the teachers of “Foreign Language course” as well as for the future teachers

Computer modeling of shear strain in the polymer brushes

R.A.G. acknowledge the financial support by the Russian Science Foundation under grant “Methods of microstructural nonlinear analysis, wave dynamics and mechanics of composites for research and design of modern metamaterials and elements of structures made on its base” (No 15-19- 10008)

Study of the association of rs3746444 of the MIR499A gene and rs6922269 of the MTHFD1L gene with progressive atherosclerosis in patients with coronary heart disease

The aim of the study is to evaluate the association of some molecular genetic markers with progressive atherosclerosis. Material and methods. In total, the study included 202 patients (147 men and 55 women), who were divided into 2 groups. The 1st (main) group included patients with coronary artery disease (100 people) who had a combination of two or more cardiovascular events during the last 2 years before inclusion: myocardial infarction or unstable angina pectoris, arterial stenting for urgent indications (coronary and peripheral), stroke; acute ischemia, thrombosis or amputation of the lower extremities. The 2nd group (comparisons) included 102 patients with coronary artery disease who did not have any of the above cardiovascular events during the last 2 years before inclusion. DNA was isolated from peripheral blood samples by phenol-chloroform extraction. Results. In the group with progressive atherosclerosis at the age of 55 years and older, the AA rs3746444 genotype of the MIR499A gene was absent in both men and women, while in the control group its frequency reached 8.3 % (p = 0.044). The odds ratio of detecting the carriage of the heterozygous genotype AG of the rs6922269 polymorphism of the MTHFD1L gene in the group with progressive atherosclerosis is 0.5 times lower compared to the control group (95 % confidence interval 0.3–0.9; p = 0.034). Conclusions. Carrying the AA genotype rs3746444 of the MIR499A gene is a conditionally protective factor against the development of progressive atherosclerosis at the age of 55 years and older. Carrying the AG genotype of the rs6922269 polymorphism of the MTHFD1L gene is associated with a reduced likelihood of developing progressive atherosclerosis in patients with CAD

Investigation of the change in the dimensions of the domains of a polymer ferroelectric system in an external electric field

С помощью метода Монте-Карло проведено изучение влияния внешнего электрического поля на свойства фазовых переходов и размеров домена в полимерных сегнетоэлектрических системах. Показано, что включение поля приводит к изменению размеров домена, увеличению критической температуры ТС и «размытию» фазового перехода.Using the Monte Carlo method carried out to study the influence of an external electric field on the properties of phase transitions and the domain sizes in the ferroelectric polymer systems. It is shown that the inclusion of the field leads to a change in the domain size, an increase in the critical temperature of the TС, and a "blurring" of the phase transition.Работа выполнена в рамках гранта РНФ «Методы микроструктурного нелинейного анализа, волновой динамики и механики композитов в исследовании и дизайне современных метаматериалов и элементов конструкций на их основе» (№ 15-19-10008)

Ультразвуковое исследование при планировании операций по поводу меланомы кожи конечностей

We performed a retrospective analysis of ultrasound scans in 42 patients with cutaneous melanoma of the extremities in planning the closure of skin defects with skin fascial island flaps supplied by perforating vessels. First, the primary melanoma focus was scanned by ultrasound to reveal characteristics of the skin, tumor and adjacent tissues. Then we detected perforating vessels to mark them and to select the sites for the island flaps. Ultrasound examination was performed using the IU 22 PHILIPS, GE Logiq E9 and Supersonic imagine AIxPLORER MultiWave Systems with linear multi-frequency sensors (517 MHz) in the B-mode, color and power Doppler to visualize the blood flow. We clarified the criteria of the necessary and sufficient parameters according to Doppler ultrasound visualization for surgical treatment of cutaneous melanoma of the extremities by the suggested method in preoperative period, as well as monitoring of the flap state after surgery. The transfer of flaps on perforating vessels did not cause blood flow disorders in them: the mean arterial blood flow velocity was 13.1 ± 4.7 cm/sec before surgery and 12.8 ± 5.4 cm/sec after it. The maximal venous flow velocity was on average 7.0 ± 1.3 cm/sec before surgery and 6.2 ± 0.8 cm/sec after it. Thus, triplex ultrasound significantly facilitates the selection and individual design of the flap with the inclusion of feeding vessels of sufficient potential, helps in planning the operation, reduces the risk of failure and improves the results of treatment. This method contributes to the radicalization of surgical intervention with a simultaneous decrease in the risk of postoperative complications and acceleration of medical and social rehabilitation of patients.Проведен ретроспективный анализ ультразвуковых исследований у 42 больных меланомой кожи конечностей при планировании закрытия кожного дефекта островковыми кожно-фасциальными лоскутами на перфорантных сосудах. Вначале выполнялось УЗИ первичного очага меланомы для уточнения характеристик кожи, опухоли, прилежащих тканей. Затем осуществлялся поиск перфорантных сосудов для их маркировки и определения расположения островковых лоскутов. УЗИ выполнены на экспертных аппаратах «IU 22 PHILIPS», GE «Logiq E9», «Supersonic imagine AIxPLORER multi Wave» линейными мультичастотными датчиками (5–17 мГц) в В-режиме, цветовом и энергетическом картировании кровотока. Уточнены критерии необходимых и достаточных параметров по результатам сонодопплерографической визуализации для хирургического лечения меланомы кожи конечностей по предлагаемому способу в предоперационном периоде и мониторинг состояния лоскутов после операции. Было установлено, что перемещение лоскутов на перфорантных сосудах не приводило к нарушениям кровотока в них: до операции средняя скорость артериального кровотока составила 13,1±4,7 см/с, после операции – 12,8±5,4 см/с. Максимальная венозная скорость до операции в среднем была 7,0±1,3 см/с, после операции – 6,2±0,8 см/с. Таким образом, триплексное сканирование значительно облегчает выбор и индивидуальный дизайн лоскута с включением в него питающих сосудов достаточного потенциала, существенно помогает в планировании операции, снижет риск неудач и способствует улучшению результатов лечения. Данный метод способствует повышению радикальности хирургического вмешательства с одновременным снижением риска послеоперационных осложнений, ускорением медицинской и социальной реабилитации больных