Electrochemical dna sensor based on poly(Azure a) obtained from the buffer saturated with chloroform

Electropolymerized redox polymers offer broad opportunities in detection of biospecific interactions of DNA. In this work, Azure A was electrochemically polymerized by multiple cycling of the potential in phosphate buffer saturated with chloroform and applied for discrimination of the DNA damage. The influence of organic solvent on electrochemical properties of the coating was quantified and conditions for implementation of DNA in the growing polymer film were assessed using cyclic voltammetry, quartz crystal microbalance, and electrochemical impedance spectros-copy. As shown, both chloroform and DNA affected the morphology of the polymer surface and electropolymerization efficiency. The electrochemical DNA sensor developed made it possible to distinguish native and thermally and chemically damaged DNA by changes in the charge transfer resistance and capacitance. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.This research was funded by Russian Science Foundation, grant number 17‐73‐20024

Sparkling extreme-ultraviolet bright dots observed with Hi-C

Observing the Sun at high time and spatial scales is a step toward understanding the finest and fundamental scales of heating events in the solar corona. The high-resolution coronal (Hi-C) instrument has provided the highest spatial and temporal resolution images of the solar corona in the EUV wavelength range to date. Hi-C observed an active region on 2012 July 11 that exhibits several interesting features in the EUV line at 193 Å. One of them is the existence of short, small brightenings "sparkling" at the edge of the active region; we call these EUV bright dots (EBDs). Individual EBDs have a characteristic duration of 25 s with a characteristic length of 680 km. These brightenings are not fully resolved by the SDO/AIA instrument at the same wavelength; however, they can be identified with respect to the Hi-C location of the EBDs. In addition, EBDs are seen in other chromospheric/coronal channels of SDO/AIA, which suggests a temperature between 0.5 and 1.5 MK. Based on their frequency in the Hi-C time series, we define four different categories of EBDs: single peak, double peak, long duration, and bursty. Based on a potential field extrapolation from an SDO/HMI magnetogram, the EBDs appear at the footpoints of large-scale, trans-equatorial coronal loops. The Hi-C observations provide the first evidence of small-scale EUV heating events at the base of these coronal loops, which have a free magnetic energy of the order of 1026 erg. © 2014. The American Astronomical Society. All rights reserved

The Fundamental Structure of Coronal Loops

During the past ten years, solar physicists have attempted to infer the coronal heating mechanism by comparing observations of coronal loops with hydrodynamic model predictions. These comparisons often used the addition of sub ]resolution strands to explain the observed loop properties. On July 11, 2012, the High Resolution Coronal Imager (Hi ]C) was launched on a sounding rocket. This instrument obtained images of the solar corona was 0.2 ]0.3'' resolution in a narrowband EUV filter centered around 193 Angstroms. In this talk, we will compare these high resolution images to simultaneous density measurements obtained with the Extreme Ultraviolet Imaging Spectrograph (EIS) on Hinode to determine whether the structures observed with Hi ]C are resolved

Digital receivers for low-frequency radio telescopes UTR-2, URAN, GURT

This paper describes digital radio astronomical receivers used for decameter and meter wavelength observations. This paper describes digital radio astronomical receivers used for decameter and meter wavelength observations. Since 1998, digital receivers performing on-the-fly dynamic spectrum calculations or waveform data recording without data loss have been used at the UTR-2 radio telescope, the URAN VLBI system, and the GURT new generation radio telescope. Here we detail these receivers developed for operation in the strong interference environment that prevails in the decameter wavelength range. Data collected with these receivers allowed us to discover numerous radio astronomical objects and phenomena at low frequencies, a summary of which is also presented.Comment: 24 pages, 15 figure

SphinX soft X-ray spectrophotometer: Science objectives, design and performance

The goals and construction details of a new design Polish-led X-ray spectrophotometer are described. The instrument is aimed to observe emission from entire solar corona and is placed as a separate block within the Russian TESIS X- and EUV complex aboard the CORONAS-PHOTON solar orbiting observatory. SphinX uses silicon PIN diode detectors for high time resolution measurements of the solar spectra in the range 0.8–15 keV. Its spectral resolution allows for discerning more than hundred separate energy bands in this range. The instrument dynamic range extends two orders of magnitude below and above these representative for GOES. The relative and absolute accuracy of spectral measurements is expected to be better than few percent, as follows from extensive ground laboratory calibrations

SphinX: The Solar Photometer in X-Rays

Solar Photometer in X-rays (SphinX) was a spectrophotometer developed to observe the Sun in soft X-rays. The instrument observed in the energy range ≈ 1 - 15 keV with resolution ≈ 0.4 keV. SphinX was flown on the Russian CORONAS-PHOTON satellite placed inside the TESIS EUV and X telescope assembly. The spacecraft launch took place on 30 January 2009 at 13:30 UT at the Plesetsk Cosmodrome in Russia. The SphinX experiment mission began a couple of weeks later on 20 February 2009 when the first telemetry dumps were received. The mission ended nine months later on 29 November 2009 when data transmission was terminated. SphinX provided an excellent set of observations during very low solar activity. This was indeed the period in which solar activity dropped to the lowest level observed in X-rays ever. The SphinX instrument design, construction, and operation principle are described. Information on SphinX data repositories, dissemination methods, format, and calibration is given together with general recommendations for data users. Scientific research areas in which SphinX data find application are reviewed

Excitations in the Halo Nucleus He-6 Following The Li-7(gamma,p)He-6 Reaction

A broad excited state was observed in 6-He with energy E_x = 5 +/- 1 MeV and width Gamma = 3 +/- 1 MeV, following the reaction Li-7(gamma,p)He-6. The state is consistent with a number of broad resonances predicted by recent cluster model calculations. The well-established reaction mechanism, combined with a simple and transparent analysis procedure confers considerable validity to this observation.Comment: 3 pages of LaTeX, 3 figures in PostScript, approved for publication in Phys. Rev. C, August, 200

Способ пространственной обработки для радара системы контроля железнодорожного переезда

Introduction. Railway crossing is a source of increased danger for vehicles and pedestrians. To increase the safety of traffic at railway crossings, radar systems based on antenna arrays (AA) can be used. The important requirements for radar at a railway crossing are a wide field of view (up to 90 degrees) and, at the same time, a high accuracy in determining coordinates. Therefore, an analysis of methods for constructing AAs and spatial processing for an automatic traffic control system at a railway crossing seems to be a relevant research task.  Aim. Design of a method for constructing the topology of an AA and spatial processing of a radar system for monitoring traffic at a railway crossing, providing a wide field of view with a high accuracy in determining the coordinates of targets.  Materials and methods. The considered method was developed based on the theory of space-time signal processing. The design of the analyzed AA topologies was carried out by the finite element method (FEM) and the finite differ-ence time domain method (FDTD) based on segments of a microstrip transmission line.  Results. A method for constructing a filled transceiver antenna array and a beamforming algorithm, which provide high angular resolution and unambiguous measurement of the target's angular coordinates in a wide field of view with relatively low computational complexity, was developed. Mathematical and electrodynamic modeling of the designed AA topologies was performed. Adjusted values of the radiation patterns (RP) of the transmitting and receiving AA were obtained, which showed good agreement with the calculated values. The main design solutions regarding the construction of AA radar for a railway crossing control system are presented to provide a wide field of view when determining the coordinates of targets.  Conclusion. It was shown that the width of the resulting RP can be reduced by several times compared to the width of the receiving RP when using two transmitting antennas located at the edges of the aperture. This approach is similar to that used in the MIMO technology, although requiring no coherence of transmission channels and use of a system of orthogonal signals. The findings determine the prospects of using the developed method. Введение. Железнодорожный (ж/д) переезд является источником повышенной опасности как для автомобилей, так и для пешеходов. Для повышения безопасности движения в зоне ж/д переезда могут быть использованы радарные системы. В качестве антенн данных систем зачастую выступают антенные решетки (АР). Основными требованиями, предъявляемыми к радару на ж/д переезде, являются широкий сектор обзора (до 90°) и в то же время высокая точность определения координат целей. Является актуальным анализ способа построения АР и пространственной обработки для автоматической системы контроля движения на ж/д переезде, позволяющий обеспечить выполнение указанных требований.  Цель работы. Разработка способа построения топологии АР и пространственной обработки радара для контроля движения на ж/д переезде, с помощью которого достигается широкий сектор обзора при высокой точности определения координат целей.  Материалы и методы. Для рассматриваемого способа построения АР использованы методы теории пространственно-временной обработки сигналов. Разработка анализируемых топологий АР выполнялась методом конечных элементов и методом конечных разностей на базе отрезков микрополосковой линии передачи.  Результаты. Разработаны способ построения заполненной приемо-передающей АР и алгоритм формирования лучей, обеспечивающие высокое угловое разрешение и однозначное измерение угловых координат цели в широком секторе обзора при относительно низкой вычислительной сложности. Выполнено математическое и электродинамическое моделирование спроектированных топологий АР. Получены уточненные оценки диаграмм направленности (ДН) передающей и приемной АР, которые с высокой степенью точности совпадают с расчетными. Представлены основные конструктивные решения, касающиеся построения АР радара системы безопасности переезда, для обеспечения широкого сектора обзора при определении координат целей.  Заключение. Показано, что ширина результирующей ДН АР может быть уменьшена в несколько раз по сравнению с шириной ДН приемной решетки при использовании двух передающих антенн, расположенных по краям апертуры. Такой подход во многом аналогичен использованию технологии MIMO, но не требует обеспечения когерентности каналов передачи и применения системы ортогональных сигналов, что также определяет перспективность использования разработки

Coronal Loop Evolution Observed with AIA and Hi-C

Despite much progress toward understanding the dynamics of the solar corona, the physical properties of coronal loops are not yet fully understood. Recent investigations and observations from different instruments have yielded contradictory results about the true physical properties of coronal loops. In the past, the evolution of loops has been used to infer the loop substructure. With the recent launch of High Resolution Coronal Imager (Hi-C), this inference can be validated. In this poster we discuss the first results of loop analysis comparing AIA and Hi-C data. We find signatures of cooling in a pixel selected along a loop structure in the AIA multi-filter observations. However, unlike previous studies, we find that the cooling time is much longer than the draining time. This is inconsistent with previous cooling models