Electron-phonon interaction via Pekar mechanism in nanostructures

We consider an electron-acoustic phonon coupling mechanism associated with the dependence of crystal dielectric permittivity on the strain (the so-called Pekar mechanism) in nanostructures characterized by strong confining electric fields. The efficiency of Pekar coupling is a function of both the absolute value and the spatial distribution of the electric field. It is demonstrated that this mechanism exhibits a phonon wavevector dependence similar to that of piezoelectricity and must be taken into account for electron transport calculations in an extended field distribution. In particular, we analyze the role of Pekar coupling in energy relaxation in silicon inversion layers. Comparison with the recent experimental results is provided to illustrate its potential significance

Mathematical modeling of the interaction of a model water molecule with a membrane based on cells of double-walled open carbon nanotubes

In this work, the process of interaction of a cell of four double-walled nanotubes with a water molecule was numerically simulated. The simulation results show that under normal conditions, water molecules pass through a cell of nanotubes in a plane parallel to the length of the tubes, and in a plane perpendicular to the length, the structure for such molecules is not passable

Carotenoids and chlorophyll content in natural soap with addition of vegetative raw material

In the present study, we performed quantitative and qualitative determination of carotenoids and chlorophyll in five samples of natural soap with addition of vegetative raw material: Green tea, Chamerion angustifolium (L.) Holub, Trifolium pratense L., Alchemilla vulgaris L. and Urtica dioica L. There was developed the method of quantitative content of carotenoids and chlorophyll using spectrophotometry with analytical wavelength at 450 nm (carotenoids) and 667 nm (chlorophyll). Qualitative determination was carried out by the comparative TLC analysis. As mobile phases were used in the experiment following a mixed solvent of hexane-acetone (3: 1). Identification of carotenoids was carried out according to standard samples β -carotene and literature data

APPLICATION OF THE INTERACTIVE METHODS IN STUDENT-CENTERED HIGH SCHOOL EDUCATION

The article deals with the problem of the need to improve the level of methodological preparation of professional activities of teachers in higher education. Interactive teaching methods, which have been developing intensively lately, more actively contribute to this. Due to the self-sufficient activity and group interaction inherent in their essence, they can be useful and promising for both teachers and students. The author reveals the popular forms and methods of interactive learning in the article. Also highlights the main advantages and disadvantages of this technology. A brief overview of group work using interactive teaching methods in higher education.Keywords: university, technology, interactive learning, teacher, pedagogical skills, student. В статье рассмотрена проблема необходимости повышения уровня методической подготовки профессиональной деятельности преподавателя в высшей школе. Лучше способствуют этому интерактивные методы обучения, которые интенсивно разрабатываются в последнее время. Благодаря заложенным в их суть самостоятельной деятельности и групповом взаимодействии, они могут быть полезными и перспективными как для преподавателя, так и для студентов. Авторы раскрывают в статье популярные формы и методы интерактивного обучения. Также подчеркиваются основные преимущества и недостатки данной технологии. Кратко приведен обзор групповой работы с использованием интерактивных методов обучения в высшей школе.Ключевые слова: высшая школа, технология, интерактивное обучение, преподаватель, педагогическое мастерство, студент. У статті розглянуто проблему необхідності підвищення рівня методичної підготовки професійної діяльності викладача у вищій школі. Якнайкраше сприяють цьому інтерактивні методи навчання, що активно розробляються останнім часом. Завдяки закладеним в їх суть самостійній діяльності та груповій взаємодії, вони можуть бути корисними та перспективними як для викладача, так і для студентів. Автори розкривають у статті найпопулярніші форми і методи інтерактивного навчання. Також підкреслюються основні переваги та недоліки даної технології. Стисло наведено огляд групової роботи з використанням інтерактивних методів навчання у вищій школі.Ключові слова: вища школа, технологія, інтерактивне навчання, викладач, педагогічна майстерність, студент

Intrauterine Device Use: A New Frontier for Behavioral Neuroendocrinology

Intrauterine devices (IUDs) are the most-used reversible contraceptive method for women in the world, but little is known about their potential modulation of brain function, cognition, and behavior. This is disconcerting because research on other hormonal contraceptives, especially oral contraceptives (OCs), increasingly shows that exogenous sex hormones have behavioral neuroendocrine consequences, especially for gendered cognition, including spatial skills. Effects are small and nuanced, however, partially reflecting heterogeneity. The goal of this paper is to introduce IUD use as a new frontier for basic and applied research, and to offer key considerations for studying it, emphasizing the importance of multimodal investigations and person-specific analyses. The feasibility and utility of studying IUD users is illustrated by: scanning women who completed a functional magnetic resonance imaging mental rotations task; taking an individualized approach to mapping functional connectivity during the task using network analyses containing connections common across participants and unique to individual women, focusing on brain regions in putative mental rotations and default mode networks; and linking metrics of brain connectivity from the individualized networks to both mental rotations task performance and circulating hormone levels. IUD users provide a promising natural experiment for the interplay between exogenous and endogenous sex hormones, and they are likely qualitatively different from OC users with whom they are often grouped in hormonal contraceptive research. This paper underscores how future research on IUD users can advance basic neuroendocrinological knowledge and women’s health

The impact of particulate electron paramagnetic resonance oxygen sensors on fluorodeoxyglucose imaging characteristics detected via positron emission tomography

During a first-in-humans clinical trial investigating electron paramagnetic resonance tumor oximetry, a patient injected with the particulate oxygen sensor Printex ink was found to have unexpected fluorodeoxyglucose (FDG) uptake in a dermal nodule via positron emission tomography (PET). This nodule co-localized with the Printex ink injection; biopsy of the area, due to concern for malignancy, revealed findings consistent with ink and an associated inflammatory reaction. Investigations were subsequently performed to assess the impact of oxygen sensors on FDG-PET/CT imaging. A retrospective analysis of three clinical tumor oximetry trials involving two oxygen sensors (charcoal particulates and LiNc-BuO microcrystals) in 22 patients was performed to evaluate FDG imaging characteristics. The impact of clinically used oxygen sensors (carbon black, charcoal particulates, LiNc-BuO microcrystals) on FDG-PET/CT imaging after implantation in rat muscle (n = 12) was investigated. The retrospective review revealed no other patients with FDG avidity associated with particulate sensors. The preclinical investigation found no injected oxygen sensor whose mean standard uptake values differed significantly from sham injections. The risk of a false-positive FDG-PET/CT scan due to oxygen sensors appears low. However, in the right clinical context the potential exists that an associated inflammatory reaction may confound interpretation