The elastic electron-deuteron scattering beyond one-photon exchange

We discuss the elastic ed scattering beyond Born approximation. It is shown that the reaction amplitude contains six generalized form factors, but only three linearly independent combinations of them (we call them generalized charge, quadrupole and magnetic form factors) contribute to the reaction cross section in the second order perturbation theory. We examine two-photon exchange and find that it includes two types of diagrams, when two virtual photons interact with the same nucleon and when the photons interact with different nucleons. Estimations based on nonrelativistic calculations with the deuteron wave function for realistic NN potential show that the main contribution to the generalized charge, quadrupole and magnetic form factors comes from diagrams of the first type.Comment: v2, published version in PR

Impurity-induced moments in underdoped cuprates

We examine the effect of a nonmagnetic impurity in a two-dimensional spin liquid in the spin-gap phase, employing a drone-fermion representation of spin-1/2 operators. The properties of the local moment induced in the vicinity of the impurity are investigated and an expression for the nuclear-magnetic- resonance Knight shift is derived, which we compare with experimental results. Introducing a second impurity into the spin liquid an antiferromagnetic interaction between the moments is found when the two impurities are located on different sublattices. The presence of many impurities leads to a screening of this interaction as is shown by means of a coherent-potential approximation. Further, the Kondo screening of an impurity-induced local spin by charge carriers is discussed.Comment: 8 pages, 1 figure. To be published in Phys. Rev. B, Vol. 56, No. 1

Electron-lattice kinetics of metals heated by ultrashort laser pulses

We propose a kinetic model of transient nonequilibrium phenomena in metals exposed to ultrashort laser pulses when heated electrons affect the lattice through direct electron-phonon interaction. This model describes the destruction of a metal under intense laser pumping. We derive the system of equations for the metal, which consists of hot electrons and a cold lattice. Hot electrons are described with the help of the Boltzmann equation and equation of thermoconductivity. We use the equations of motion for lattice displacements with the electron force included. The lattice deformation is estimated immediately after the laser pulse up to the time of electron temperature relaxation. An estimate shows that the ablation regime can be achieved.Comment: 7 pages; Revtex. to appear in JETP 88, #1 (1999

Impurity-induced spin polarization and NMR line broadening in underdoped cuprates

We present a theory of magnetic (S=1) Ni and nonmagnetic Zn impurities in underdoped cuprates. Both types of impurities are shown to induce S=1/2 moments on Cu sites in the proximity of the impurity, a process which is intimately related to the spin gap phenomenon in cuprates. Below a characteristic Kondo temperature, the Ni spin is partially screened by the Cu moments, resulting in an effective impurity spin S=1/2. We further analyze the Ruderman-Kittel-Kasiya-Yosida-type response of planar Cu spins to a polarization of the effective impurity moments and derive expressions for the corresponding ^{17}O NMR line broadening. The peculiar aspects of recent experimental NMR data can be traced back to different spatial characteristics of Ni and Zn moments as well as to an inherent temperature dependence of local antiferromagnetic correlations.Comment: PRB B1 01June9

Transformations of substituted cyanoiminooctahydroquinazolines under oxidation conditions

Substituted quinazolines of various degrees of saturation and functionalization possess a wide spectrum of biological activity, in particular, anticancer activity, which predetermines the importance of obtaining new representatives of this type of compounds and studying their practically useful properties. Methods for the preparation of 2-cyanoiminoquinazolines are poorly described in the literature, while their properties and oxidation reactions have not been studied at all. We have analyzed the stability of tautomeric forms of 2-cyanoiminoquinazolines, determined the activation energy of their formation using quantum-chemical calculations, studied their transformation under the action of strong oxidants (CrO3/AcOH, NaNO2/AcOH). Selective aromatization of the azoheterocycle and hydrolysis of the -CN-group to form 2-aminocarbamoylquinazoline occurred during oxidation. An increase in temperature from 120 to 160° C (using CrO3) resulted in the formation of 2-nitrosoquinazoline. The structure of our new obtained substances was established by spectral methods (IR, 1H, 13C NMR, HSQC, NOESY), a scheme of their formation has been proposed

Order from Disorder: Non Magnetic Impurities in the Spin-gap Phase of the Cuprates

We solve the problem of $N$ non magnetic impurities in the staggered flux phase of the Heisenberg model which we assume to be a good mean-field approximation for the spin-gap phase of the cuprates. The density of states is evaluated exactly in the unitary limit and is porportional to 1/\left (\omega \ln^2(|\omega|/D)), in analogy with the 1D case of doped spin-Peierls and two-leg ladders compounds. We argue that the system exhibits a quasi long-range order at T=0 with instantaneous spin-spin correlations decreasing as n_i/ \ln^2\left (n_i R_{ij}) for large distances $R_{ij}$ and we predict enhanced low energy fluctuations in Neutron Scattering.Comment: 4 pages, corrected typos, references adde

Electronic spectrum in high-temperature cuprate superconductors

A microscopic theory for electronic spectrum of the CuO2 plane within an effective p-d Hubbard model is proposed. Dyson equation for the single-electron Green function in terms of the Hubbard operators is derived which is solved self-consistently for the self-energy evaluated in the noncrossing approximation. Electron scattering on spin fluctuations induced by kinematic interaction is described by a dynamical spin susceptibility with a continuous spectrum. Doping and temperature dependence of electron dispersions, spectral functions, the Fermi surface and the coupling constant are studied in the hole doped case. At low doping, an arc-type Fermi surface and a pseudogap in the spectral function are observed.Comment: 13 pages (revtex), 18 figures, to be published in JET

ПЕРЕВАГИ ВИКОРИСТАННЯ ОНЛАЙН-ФОРМ ЯК ЗАСОБУ ВИКЛАДАННЯ В ІНТЕРНАТУРІ

The article deals with the results of the analysis of the effectiveness of using online forms in the process of mastering the discipline «internal diseases». A pedagogical experiment was conducted with the inclusion of 46 interns who were engaged in the department during the period 2016-2017. It was found that the use of online forms to improve the efficiency of the educational process at the expense of, firstly, reducing the time spent on processing of the survey results, and, secondly, the optimization of the material assimilation level and «survival» knowledge of medical interns using a visual representation the results of the initial test and the substantive discussion on problematic issues. The combination of the online interviewing as a form of testing with the traditional way of control, and with self-control, can lead to a real system of objective assessment of the knowledge and realization of the main task of the educational process — the formation of strong knowledge and provide high-quality training of future specialists.В статье представлены результаты анализа эффективности использования онлайн-форм в процессе освоения дисциплины «внутренние болезни». Проведен педагогический эксперимент с включением 46 врачей-интернов, которые занимались на кафедре в период 2016-2017 годов. Установлено, что использование онлайн-форм позволяет повысить эффективность учебного процесса за счет, во-первых, уменьшения времени, затрачиваемого на обработку результатов опроса, и, во-вторых, оптимизации уровня усвоения материала и «выживаемости» знаний врачей-интернов с помощью наглядного представления результатов исходного испытания и предметной дискуссии по проблемным вопросам. Онлайн-опрос характеризуется большей объективностью и, как следствие, более выраженным положительным стимулирующим влиянием на познавательную деятельность врача-интерна. В предлагаемой методике проверка выполнения ситуационных задач выполняется централизованно, по единым критериям, что позволяет с достаточным основанием судить об общей степени овладения соответствующими знаниями и навыками, выявлять типичные ошибки и на этом основании корректировать, а в дальнейшем — совершенствовать учебный процесс. Сочетание онлайн-опроса как формы проверки с традиционными средствами контроля, а также с самоконтролем может способствовать выработке реальной системы объективной оценки знаний и реализации главной задачи образовательного процесса — формированию прочных знаний и обеспечению высокого качества подготовки будущих специалистов.У статті наведено результати аналізу ефективності використання онлайн-форм у процесі опанування дисципліни «внутрішні хвороби». Проведено педагогічний експеримент із включенням 46 лікарів-інтернів, які займалися на кафедрі в період 2016-2017 років. Встановлено, що використання онлайн-форм дозволяє підвищити ефективність навчального процесу за рахунок, по-перше, зменшення часу, який витрачається на обробку результатів опитування, і, по-друге, поліпшення рівня засвоєння матеріалу та «виживаності» знань лікарів-інтернів за допомогою наочного представлення результатів вихідного випробування і предметної дискусії з проблемних питань. Онлайн-опитування характеризується більшою об'єктивністю і, як наслідок, більш позитивним стимулюючим впливом на пізнавальну діяльність лікаря-інтерна. У запропонованій методиці перевірка виконання ситуаційних завдань виконується централізовано, за єдиними критеріями, що дозволяє з достатньою підставою судити про загальний ступінь сформо-ваності відповідних знань та навиків, виявляти типові помилки і на цій основі корегувати та надалі вдосконалювати навчальний процес. Поєднання онлайн-опитування як форми перевірки з традиційними засобами контролю, а також із самоконтролем може сприяти виробленню реальної системи об'єктивної оцінки знань і реалізації головного завдання освітнього процесу — формуванню міцних знань і забезпеченню високої якості підготовки майбутніх фахівців

Modern aspects of the use of plasma enriched in soluble platelet factors in the treatment of injuries and diseases of the musculoskeletal system

The review of literature presents the new direction in the treatment of sports injuries and diseases of the musculoskeletal system – using of autologous platelet-rich plasma/plasma enriched in soluble platelet factors (PRP/PORFT). PRP/PORFT reveals anti-inflammatory, analgesic, anticatabolic and regenerative effects after local injection to affected area. Technology of preparation and clinical application of PRP/PORFT were under consideration. There were described the results of clinical studies on PRP/PORFT application in sports medicine and damage of musculoskeletal system. It was shown the clinical efficacy of 2-3 injections of PRP/PORFT into the area of muscle, ligaments, joints injury. Most effective use of PRP/PORFT was shown for therapy of lateral epicondylitis and osteoarthritis. There were no yet evidences for its efficacy in therapy of patients with damaged Achilles tendon. The best clinical effects of PRP/PORFT use was demonstrated in patients with trauma and damage of musculoskeletal system at the initial stages of treatment, and also as a part of rehabilitation courses

IAPT/IOPB chromosome data 16

[EN] Inula helenioides DC., I. langeana Beck, I. maletii Maire, I. montana L., I. oculus-christi L., I. salicina L. (Asteraceae)