Advanced magneto-optical microscopy: Imaging from picoseconds to centimeters - imaging spin waves and temperature distributions (invited)

© 2016 Author(s).Recent developments in the observation of magnetic domains and domain walls by wide-field optical microscopy based on the magneto-optical Kerr, Faraday, Voigt, and Gradient effect are reviewed. Emphasis is given to the existence of higher order magneto-optical effects for advanced magnetic imaging. Fundamental concepts and advances in methodology are discussed that allow for imaging of magnetic domains on various length and time scales. Time-resolved imaging of electric field induced domain wall rotation is shown. Visualization of magnetization dynamics down to picosecond temporal resolution for the imaging of spin-waves and magneto-optical multi-effect domain imaging techniques for obtaining vectorial information are demonstrated. Beyond conventional domain imaging, the use of a magneto-optical indicator technique for local temperature sensing is shown

Features of the reactive oxygen species generation using cationic chlorin photosensitizers

Были изучены особенности генерации активных форм кислорода с помощью катионных хлориновых фотосенсибилизаторов. Была отмечена хорошая сходимость результатов, полученных разными методами, продемонстрировано для всех исследованных соединений, за исключением ФС с близким внутримолекулярным расположение двух катионных групп

Monocationic chlorin – new promising photosensitizer for antitumor and antimicrobial photodynamic therapy

В статье описан новый перспективный монокатионный фотосенсибилизатор для противоопухолевой и антимикробной терапии на основе природного хлорофилла. Этот новый фотосенсибилизирующий агент (McChl) получают из метилфеофорбида по двухстадийной методике

Elastic Spin Relaxation Processes in Semiconductor Quantum Dots

Electron spin decoherence caused by elastic spin-phonon processes is investigated comprehensively in a zero-dimensional environment. Specifically, a theoretical treatment is developed for the processes associated with the fluctuations in the phonon potential as well as in the electron procession frequency through the spin-orbit and hyperfine interactions in the semiconductor quantum dots. The analysis identifies the conditions (magnetic field, temperature, etc.) in which the elastic spin-phonon processes can dominate over the inelastic counterparts with the electron spin-flip transitions. Particularly, the calculation results illustrate the potential significance of an elastic decoherence mechanism originating from the intervalley transitions in semiconductor quantum dots with multiple equivalent energy minima (e.g., the X valleys in SiGe). The role of lattice anharmonicity and phonon decay in spin relaxation is also examined along with that of the local effective field fluctuations caused by the stochastic electronic transitions between the orbital states. Numerical estimations are provided for typical GaAs and Si-based quantum dots.Comment: 57 pages, 14 figure

Research of GIS-services applicability for solution of spatial analysis tasks

Experiments for working out the areas of applying various gis-services in the tasks of spatial analysis are discussed in this paper. Google Maps, Yandex Maps, Microsoft SQL Server are used as services of spatial analysis. All services have shown a comparable speed of analyzing the spatial data when carrying out elemental spatial requests (building up the buffer zone of a point object) as well as the preferences of Microsoft SQL Server in operating with more complicated spatial requests. When building up elemental spatial requests, internet-services show higher efficiency due to cliental data handling with JavaScript-subprograms. A weak point of public internet-services is an impossibility to handle data on a server side and a barren variety of spatial analysis functions. Microsoft SQL Server offers a large variety of functions needed for spatial analysis on the server side. The authors conclude that when solving practical problems, the capabilities of internet-services used in building up routes and completing other functions with spatial analysis with Microsoft SQL Server should be involved

Charge Radii and Magnetic Polarizabilities of the Rho and K* Mesons in QCD String Theory

The effective action for light mesons in the external uniform static electromagnetic fields was obtained on the basis of QCD string theory. We imply that in the presence of light quarks the area law of the Wilson loop integral is valid. The approximation of the Nambu-Goto straight-line string is used to simplify the problem. The Coulomb-like short-range contribution which goes from one-gluon exchange is also neglected. We do not take into account spin-orbital and spin-spin interactions of quarks and observe the $\rho$ and $K^*$ mesons. The wave function of the meson ground state is the Airy function. Using the virial theorem we estimate the mean charge radii of mesons in terms of the string tension and the Airy function zero. On the basis of the perturbative theory, in the small external magnetic field we find the diamagnetic polarizabilities of $\rho$ and $K^*$ mesons: $\beta_\rho =-0.8\times 10^{-4} {fm}^3$, $\beta_{K^*}=-0.57\times 10^{-4} {fm}^3$Comment: 22 pages, no figures, in LaTeX 2.09, typos correcte

Исследование острой токсичности монокатионного производного хлорина е6 – перспективного фотосенсибилизатора для антимикробной и противоопухолевой фотодинамической терапии

In this experimental work the acute toxicity of a chemically modified derivative of the natural pigment chlorophyll a called monocationic chlorin e6, which is a promising photosensitizer (PS) for antimicrobial and antitumor photodynamic therapy, was studied using white rats. The advantages of the PS under investigation are an intense absorption in the long-wavelength region of the visible spectrum, a sufficiently high quantum yield of singlet oxygen generation, pronounced amphiphilic properties along with an appropriate solubility in water, and a high level of photocytotoxic- ity in relation to both malignant HeLa cells and antibiotic-resistant hospital strains of E. сoli bacteria., P. aerugenosa and others. It has been shown that the value of LD50 of the considered PS can be calculated as the value of 100 mg/kg. In the reproduced experimental model of acute toxicity, pathomorphological changes in the vital organs of laboratory animals indicate a pronounced vasopathic effect of the drug with the development of cerebral edema and respiratory distress syndrome, which have become the main signs of thanatogenesis.На белых крысах изучены особенности острой токсичности химически модифицированного производного природного пигмента хлорофилла а монокатионного хлорина e6 – перспективного фотосенсибилизатора (ФС) для антимикробной и противоопухолевой фотодинамической терапии. Преимуществами ФС являются интенсивное поглощение в длинноволновой области видимого спектра, достаточно высокий квантовый выход генерации синглетного кислорода, выраженные амфифильные свойства наряду с хорошей растворимостью в воде и высокий уровень фотоцитотоксичности в отношении как злокачественных клеток линии HeLa, так и антибиотикорезистентных госпитальных штаммов бактерий E. coli, P. Aerugenosa и других. Величина ЛД50 для монокатионного хлорина e6 составляет 100 мг/кг массы тела. В воспроизведенной экспериментальной модели острой токсичности патоморфологические изменения жизненно важных органов лабораторных животных свидетельствуют о выраженном вазопатическом действии препарата с развитием отека головного мозга и респираторного дистресс-синдрома, ставшими основными звеньями танатогенеза

Final NOMAD results on nu_mu->nu_tau and nu_e->nu_tau oscillations including a new search for nu_tau appearance using hadronic tau decays

Results from the nu_tau appearance search in a neutrino beam using the full NOMAD data sample are reported. A new analysis unifies all the hadronic tau decays, significantly improving the overall sensitivity of the experiment to oscillations. The "blind analysis" of all topologies yields no evidence for an oscillation signal. In the two-family oscillation scenario, this sets a 90% C.L. allowed region in the sin^2(2theta)-Delta m^2 plane which includes sin^2(2theta)<3.3 x 10^{-4} at large Delta m^2 and Delta m^2 < 0.7 eV^2/c^4 at sin^2(2theta)=1. The corresponding contour in the nu_e->nu_tau oscillation hypothesis results in sin^2(2theta)<1.5 x 10^{-2} at large Delta m^2 and Delta m^2 < 5.9 eV^2/c^4 at sin^2(2theta)=1. We also derive limits on effective couplings of the tau lepton to nu_mu or nu_e.Comment: 46 pages, 16 figures, Latex, to appear on Nucl. Phys.