Quasi-binary amorphous phase in a 3D system of particles with repulsive-shoulder interactions

We report a computer-simulation study of the equilibrium phase diagram of a three-dimensional system of particles with a repulsive step potential. Using free-energy calculations, we have determined the equilibrium phase diagram of this system. At low temperatures, we observe a number of distinct crystal phases. However, under certain conditions the system undergoes a glass transition in a regime where the liquid appears thermodynamically stable. We argue that the appearance of this amorphous low-temperature phase can be understood by viewing this one-component system as a pseudo-binary mixture.Comment: 4 pages, 4 figure

СТРАТЕГІЯ ІНФОРМАТИЗАЦІЇ МЕДИЧНОГО УНІВЕРСИТЕТУ

The work deals with the model of informatization of medical university on the example of Zaporizhyan State MedicalUniversity, built on the principles of systems analysis of pedagogical system of the medical personnel training.В работе рассматривается модель информатизации медицинс о о ниверситета на примере Запорожс о о ос -дарственно о медицинс о о ниверситета, построенная на принципах системно о анализа педа о ичес ой систе-мы под отов и медицинс их адров.В роботі розглядається модель інформатизації медичного університету на прикладі Запорізького державного медичного університету, яка побудована на принципах системного аналізу педагогічної системи підготовки медичних кадрів

Two liquid states of matter: A new dynamic line on a phase diagram

It is generally agreed that the supercritical region of a liquid consists of one single state (supercritical fluid). On the other hand, we show here that liquids in this region exist in two qualitatively different states: "rigid" and "non-rigid" liquid. Rigid to non-rigid transition corresponds to the condition {\tau} ~ {\tau}0, where {\tau}is liquid relaxation time and {\tau}0 is the minimal period of transverse quasi-harmonic waves. This condition defines a new dynamic line on the phase diagram, and corresponds to the loss of shear stiffness of a liquid at all available frequencies, and consequently to the qualitative change of many important liquid properties. We analyze the dynamic line theoretically as well as in real and model liquids, and show that the transition corresponds to the disappearance of high-frequency sound, qualitative changes of diffusion and viscous flow, increase of particle thermal speed to half of the speed of sound and reduction of the constant volume specific heat to 2kB per particle. In contrast to the Widom line that exists near the critical point only, the new dynamic line is universal: it separates two liquid states at arbitrarily high pressure and temperature, and exists in systems where liquid - gas transition and the critical point are absent overall.Comment: 21 pages, 8 figure

Depolarization volume and correlation length in the homogenization of anisotropic dielectric composites

In conventional approaches to the homogenization of random particulate composites, both the distribution and size of the component phase particles are often inadequately taken into account. Commonly, the spatial distributions are characterized by volume fraction alone, while the electromagnetic response of each component particle is represented as a vanishingly small depolarization volume. The strong-permittivity-fluctuation theory (SPFT) provides an alternative approach to homogenization wherein a comprehensive description of distributional statistics of the component phases is accommodated. The bilocally-approximated SPFT is presented here for the anisotropic homogenized composite which arises from component phases comprising ellipsoidal particles. The distribution of the component phases is characterized by a two-point correlation function and its associated correlation length. Each component phase particle is represented as an ellipsoidal depolarization region of nonzero volume. The effects of depolarization volume and correlation length are investigated through considering representative numerical examples. It is demonstrated that both the spatial extent of the component phase particles and their spatial distributions are important factors in estimating coherent scattering losses of the macroscopic field.Comment: Typographical error in eqn. 16 in WRM version is corrected in arxiv versio

Молекулярно-биологические особенности анапластических астроцитом и выделение молекулярных подгрупп их IDH1-мутантных форм с помощью анализа in silico

Aim. The problem of anaplastic astrocytomas is quite relevant today. The WHO classification distinguishes IDH1/IDH2 mutant anaplastic astrocytomas, anaplastic astrocytomas without IDH1/IDH2 mutations, and anaplastic astrocytomas not otherwise specified. The aim of this work was to cluster IDH1-mutant anaplastic astrocytomas based on their cytogenetic profile to select prognostically significant molecular subgroups, which can have both clinical and fundamental scientific value.Materials and methods. In this work, we performed a cluster analysis of anaplastic astrocytomas according to their cytogenetic profiles based on available genetic databases of tumors and large cohort studies, as well as a comparison of Kaplan – Meyer survival curves for various molecular subgroups of patients.Results. We studied the main genetic features of the inter-tumor heterogeneity of anaplastic astrocytomas and distinguished seven molecular subgroups based on the cytogenetic profile: embryo-like, inflammatory-like, deletion, matrix, cyclin, GATA3-dependent and tyrosine kinase. Moreover, each of these subgroups has not only distinctive molecular characteristics, but also important clinical features.Conclusion. A detailed study of the molecular properties of anaplastic astrocytomas will not only optimize the process for predicting treatment outcomes, but also create innovative formats for targeted therapy within the framework of the concept of personalized medicine.Актуальность. Проблема анапластических астроцитом достаточно актуальна в наши дни. В классификации Всемирной организации здравоохранения выделяются анапластическая астроцитома с мутацией в генах IDH1 и IDH2, анапластическая астроцитома без мутаций в генах IDH1 и IDH2, анапластическая астроцитома без дополнительного генетического уточнения.Целью данной работы стало кластерирование анапластических астроцитом с мутацией в гене IDH1 на основе их цитогенетического профиля для выделения прогностически значимых молекулярных подгрупп, которые могут иметь как клинико-практическое, так и фундаментально-научное значение. Проведен кластерный анализ анапластических астроцитом по их цитогенетическим профилям на основе доступных генетических баз данных опухолей и крупных когортных исследований, а также сравнение кривых  выживаемости Каплана – Мейера для различных молекулярных подгрупп пациентов.Результаты. Нам удалось изучить основные генетические особенности межопухолевой гетерогенности анапластических астроцитом и выделить на основе цитогенетического профиля семь молекулярных подгрупп – эмбриональноподобную, инфламмоподобную, делеционную, матриксную, циклиновую, GATA3-зависимую и тирозинкиназную. При этом каждая из этих подгрупп имеет не только отличительные молекулярные характеристики, но и важные клинические особенности.Заключение. Детальное изучение молекулярных свойств анапластических астроцитом позволит не только оптимизировать процесс прогнозирования исходов лечения, но и создать инновационные форматы для таргетной терапии в рамках концепции персонализированной медицины

СТРАТЕГІЯ ВПРОВАДЖЕННЯ КУРСІВ ЗА ВИБОРОМ НА БАЗІ ТЕХНОЛОГІЇ ОНЛАЙН-КУРСІВ НА ПЛАТФОРМІ edX

A sequential strategy of implementation elective online courses at medical university on the basis of distance learning technology is revealed in the article. It is shown that successful implementation of online courses is possible in the presence of such components as academic staff readiness to develop new learning technologies and the acceptance of the fact of their changing role in the educational process; students’ readiness to use distance learning technologies; availability of infrastructure at university that provides distance learning services; presence of a quality assurance system for courses content. Particular attention is paid to the need to change the structural organization of the educational process and the role of instructors in the implementation process. The authors substantiated their choice of the Open edX platform for online courses development based on some criteria.У статті розкрита послідовна стратегія впровадження в медичному університеті курсів за вибором на базі технології дистанційного навчання у вигляді онлайн-курсів. Показано, що успішне впровадження онлайн-курсів можливо при наявності таких складових, як: готовність викладацького складу до опанування нових технологій навчання та зміни своєї ролі в навчальному процесі; готовність студентів до використання дистанційних технологій навчання; наявність інфраструктури в університеті, яка забезпечує сервіси дистанційного навчання; наявність системи перевірки якості контенту онлайн-курсів, які розробляються. Особлива увага звертається на необхідність зміни структури навчального процесу та ролі викладачів при впровадженні онлайн-курсів. Авторами обґрунтовано вибір платформи для розробки онлайн-курсів Open edX за критеріями

Large N Quantum Time Evolution Beyond Leading Order

For quantum theories with a classical limit (which includes the large N limits of typical field theories), we derive a hierarchy of evolution equations for equal time correlators which systematically incorporate corrections to the limiting classical evolution. Explicit expressions are given for next-to-leading order, and next-to-next-to-leading order time evolution. The large N limit of N-component vector models, and the usual semiclassical limit of point particle quantum mechanics are used as concrete examples. Our formulation directly exploits the appropriate group structure which underlies the construction of suitable coherent states and generates the classical phase space. We discuss the growth of truncation error with time, and argue that truncations of the large-N evolution equations are generically expected to be useful only for times short compared to a ``decoherence'' time which scales like N^{1/2}.Comment: 36 pages, 2 eps figures, latex, uses revtex, epsfig, float