Cytogenetic effects of neutron therapy in patients with parotid gland tumors and relapse of breast cancer

Aim:To assess the frequency and spectrum of chromosome aberrations and micronuclei in peripheral blood lymphocytes of patients with parotid salivary gland tumors and relapse of breast cancer during the course of neutron therapy. Materials and Methods: Samples of peripheral blood were obtained from 9 patients with parotid salivary gland tumors (T3N0–3M0) and 8 patients with relapse of breast cancer before, after first fraction and at the end of neutron therapy. The treatment course specified 5.5–8.4 Gy (equivalent to 23–44 Gy of photon irradiation) with 1.3–2.2 Gy per fraction for patients with parotid salivary gland tumors and 4,8–8.0 Gy (equivalent to 30–40 Gy of photon irradiation) with 1.6 Gy per fraction for patients with relapse of breast cancer. Control group established for conventional cytogenetic analysis consisted of 15 healthy persons. Assessment of chromosome aberrations frequency was performed on routinely stained metaphase plates. Lymphocytes from the same patients were analyzed by micronucleus test in combination with fluorescent in situ hybridization (FISH) using pancentromeric DNA probe. Results: Level of chromosome aberrations and micronuclei significantly increased in lymphocytes of patients from both groups during neutron therapy (P < 0.05). This increase was mainly due to chromosome-type aberrations and centromere-negative micronuclei. The prevalent types of aberrations are in agreement with theoretical mechanisms of neutron effects on cells. Conclusion: Cytogenetic effects of fast neutron therapy in lymphocytes of patients with parotid salivary gland tumors and relapse of breast cancer were observed. A positive dynamics of radiation-induced chromosomal damages formation during the course was denoted in lymphocytes of cancer patients in both groups

Temperature Effect on the Stability of the Polarized State Created by Local Electric Fields in Strontium Barium Niobate Single Crystals

The stability of ferroelectric domain patterns at the nanoscale has been a topic of much interest for many years. We investigated the relaxation of the polarized state created by application of a local electric field using a conductive tip of a scanning probe microscope for the model uniaxial relaxor system SrxBa1−xNb2O6 (SBN) in its pure and Ce-doped form. The temporal relaxation of the induced PFM contrast was measured at various temperatures. The average value of the induced contrast decreases during heating for all investigated crystals. Below the freezing temperature the induced state remains stable after an initial relaxation. Above the freezing temperature the induced state is unstable and gradually decays with time. The stability of the induced state is strongly affected by the measuring conditions, so continuous scanning results in a faster decay of the poled domain. The obtained effects are attributed to a decrease of the induced polarization and backswitching of the polarized area under the action of the depolarization field

Role of radial electric field in LH transition triggered by counter-NBI at low plasma Density in the TUMAN-3M tokamak

Threshold power needed to attain H-mode in a tokamak is a critical parameter for designing of future devices and in particular fusion reactor ITER [1]. According to commonly accepted scaling [2] the threshold power Pthr increases with average density ne when the density exceeds some ne min at which Pthr is minimal. An increase in the Pthr towards low density was observed in many experiments [3-6], prevents the transition at lower ne as well. Physics of the threshold power increase at low ne is not well understood. Since the radial electric field Er and Er×B sheared flow play important roles in the LH transition one could expect these quantities effect the low transitions. Toroidal rotation and radial electric field generation during counter-NBI have been studied in [7] and recently reconsidered theoretically in [8]. Thus, motivation for the presented study is to analyze effect of counter-NBI on the LH transition at low density.Гранична потужність Pthr, необхідна для переходу в H-режим, є критичним параметром при проектуванні термоядерних установок, у тому числі реактора ITER [1]. Відповідно до загальноприйнятого скейлинга [2] Pthr збільшується з ростом середньої щільності плазми ne, якщо ne перевершує деяке значення, при якому Pthr мінімальна. Збільшення Pthr при низьких щільностях також спостерігалося в багатьох експериментах [3-6]. Фізика цього явища до кінця не з'ясована. Однак, з огляду на той факт, що радіальне електричне поле Er і Er×B обертання плазми відіграють важливу роль у механізмі LH-переходу, можна очікувати, що ці фактори впливають і на LH-перехід при низьких щільностях. Явища тороїдального обертання плазми і появи Er під час контр-інжекції пучка нейтральних атомів були недавно досліджені як експериментально [7], так і теоретично [8]. Метою роботи, що представляється, є аналіз впливу контр-інжекції на процес LH-переходу при низькій щільності.Пороговая мощность Pthr, необходимая для перехода в H-режим, является критическим параметром при проектировании термоядерных установок, в том числе реактора ITER [1]. В соответствии с общепринятым скейлингом [2] Pthr увеличивается с ростом средней плотности плазмы ne, если ne превосходит некоторое значение, при котором Pthr минимальна. Увеличение Pthr при низких плотностях также наблюдалось во многих экспериментах [3-6]. Физика этого явления до конца не выяснена. Однако, учитывая тот факт, что радиальное электрическое поле Er и Er×B вращение плазмы играют важную роль в механизме LH-перехода, можно ожидать, что эти факторы влияют и на LH-переход при низких плотностях. Явления тороидального вращения плазмы и появления Er во время контр-инжекции пучка нейтральных атомов были недавно исследованы как экспериментально [7], так и теоретически [8]. Целью представляемой работы является анализ влияния контр-инжекции на процесс LH-перехода при низкой плотности

Probing exotic phenomena at the interface of nuclear and particle physics with the electric dipole moments of diamagnetic atoms: A unique window to hadronic and semi-leptonic CP violation

The current status of electric dipole moments of diamagnetic atoms which involves the synergy between atomic experiments and three different theoretical areas -- particle, nuclear and atomic is reviewed. Various models of particle physics that predict CP violation, which is necessary for the existence of such electric dipole moments, are presented. These include the standard model of particle physics and various extensions of it. Effective hadron level combined charge conjugation (C) and parity (P) symmetry violating interactions are derived taking into consideration different ways in which a nucleon interacts with other nucleons as well as with electrons. Nuclear structure calculations of the CP-odd nuclear Schiff moment are discussed using the shell model and other theoretical approaches. Results of the calculations of atomic electric dipole moments due to the interaction of the nuclear Schiff moment with the electrons and the P and time-reversal (T) symmetry violating tensor-pseudotensor electron-nucleus are elucidated using different relativistic many-body theories. The principles of the measurement of the electric dipole moments of diamagnetic atoms are outlined. Upper limits for the nuclear Schiff moment and tensor-pseudotensor coupling constant are obtained combining the results of atomic experiments and relativistic many-body theories. The coefficients for the different sources of CP violation have been estimated at the elementary particle level for all the diamagnetic atoms of current experimental interest and their implications for physics beyond the standard model is discussed. Possible improvements of the current results of the measurements as well as quantum chromodynamics, nuclear and atomic calculations are suggested.Comment: 46 pages, 19 tables and 16 figures. A review article accepted for EPJ

Relativistic Laser-Matter Interaction and Relativistic Laboratory Astrophysics

The paper is devoted to the prospects of using the laser radiation interaction with plasmas in the laboratory relativistic astrophysics context. We discuss the dimensionless parameters characterizing the processes in the laser and astrophysical plasmas and emphasize a similarity between the laser and astrophysical plasmas in the ultrarelativistic energy limit. In particular, we address basic mechanisms of the charged particle acceleration, the collisionless shock wave and magnetic reconnection and vortex dynamics properties relevant to the problem of ultrarelativistic particle acceleration.Comment: 58 pages, 19 figure

Optimization of computational complexity of lossy compression algorithms of hyperspectral images

В работе рассматривается решение задачи увеличения быстродействия алгоритма сжатия гиперспектральных изображений (ГСИ), базирующийся на методах распознавания. Предлагаются два метода уменьшения вычислительной сложности алгоритма сжатия с потерями. Первый способ основан на использовании результатов сжатия, полученных при других параметрах, в том числе и метода распознавания. Второй метод базируется на адаптивном разбиении пикселей гиперспектрального изображения на кластеры и вычислении оценок сходства только с эталонами одного из подмножеств. Получены теоретические и практические оценки увеличения быстродействия алгоритма сжатия. The paper discusses the solution of the problem of increasing the speed of the compression algorithm of hyperspectral images (HSI), based on the methods of recognition. Two methods are proposed to reduce the computational complexity of a lossy compression algorithm. The first method is based on the use of compression results obtained with other parameters, including the recognition method. The second method is based on adaptive pixel partitioning of a hyperspectral image into clusters and calculating similarity estimations only with the standards of one of the subsets. Theoretical and practical estimates of the increase in the speed of the compression algorithm are obtained.Работа выполнена при поддержке Российского Научного Фонда, проект № 16-11-00068