E. A. Shirshin$^{1,2}$, B. P. Yakimov$^{1,2}$, G. S. Budylin$^{2,3}$, N. V. Zlobina$^{1,2}$, D. A. Davydov$^{1,2}$, A. G. Armaganov$^2$, V. V. Fadeev$^1$, N. N. Sysoev$^1$, A. A. Kamalov$^2$

The optical spectroscopy and microscopy techniques are widely used for fundamental research of living systems, however, their application in clinical practice has two limitations. Firstly, the probing depth of light in biological tissues varies from tenths to several millimeters, and, secondly, the use of exogenous probes, which increase sensitivity and specificity of the detection of pathological tissues, is limited in vivo on humans. Hence, the question arises about the niche of the biomedical photonics among other physical diagnostic methods used in clinical practice. In this work we review the optical methods and certified commercially available medical devices that use photonic technologies to solve the problem of intraoperative diagnostics, i.e. the discrimination between pathological and healthy tissue sites in vivo and ex vivo by endogenous optical response. The paper considers a wide range of clinical applications, where researchers and engineers achieved high sensitivity and specificity in solving the problem of tissues classification. On the example of intraoperative diagnostics, the advantages and disadvantages of optical imaging and diagnostics methods are discussed.

D. V. Kolesov$^1$, P. V. Gorelkin$^2$, A. O. Prelovskaya$^{1,2}$, A. S. Erofeev$^{1,2}$

Scanning electrochemical microscopy (SECM), which makes it possible to simultaneously obtain topography and information about the local electrical properties of a surface, is a type of probe microscopy technique. Due to the abundance of developed techniques, SECM makes it possible to solve a wide range of problems in the study of the electroactive properties of materials. SECM is of particular interest for research in the field of energy storage and, in particular, lithium-ion batteries (LIB). Recent advances in battery research have shown that the electrochemical properties exhibited by materials at the macro level differ significantly at the micro level. Owing to the high spatial resolution, the SECM methods provide unique information about the processes occurring in the LIB at the micro- and nanoscale. This review is an introduction to the broad field of SECM and focuses on the basic operating principles and use cases for energy storage research.

An Investigation on Production Routes of $^{230}$U Radioisotope used in Targeted Alpha Therapy by Different Level Density Models

H. Özdoğan$^1$, M. Şekerci$^2$, M. Cinoğlu Karaca$^5$, M. Okutan$^3$, B. Demir$^4$, A. Kaplan$^2$

Targeted alpha therapy (TAT) is an attractive therapeutic option in patients with multiple micrometastases. It offers many advantages, including easy administration, the ability to treat multiple lesions simultaneously and the possibility of combination with other therapeutic approaches for improved efficacy. The aim of this study is to investigate the optimum production route of $^{230}$U, which is a promising TAT isotope, in cyclotrons. For this, $^{231}$Pa(p,2n) $^{230}$U, $^{231}$Pa(d,3n)$^{230}$U, $^{232}$Th(p,3n)$^{230}$Pa and $^{232}$Th(d,4n)$^{230}$Pa reactions cross–sections, total activity and reaction yield have been calculated by using different level density models of TALYS 1.95 code. It is possible to produce an $^{230}$U activity of 53.491 mCi via on $^{231}$Pa(p,2n)$^{230}$U direct route with 12.8 MeV protons at 1 mA current for 24 hours. After a 28 days waiting period required for undesirable product ($^{231}$U) activity to decrease sufficiently, this activity decreases to 21.4 mCi and by considering the average dose per patient as 0.5 mCi, these activities are enough for 43 patients. Besides, $^{231}$Pa is already the target material in this direct production route and $^{231}$Pa obtained from undesirable product $^{231}$U can be stored and processed for re-use as the target material. In this way, a significant amount of source material can be recovered.

Evaluation of beam deflection, longitudinal retraction and depth-dose perturbation of helium ion beams under transverse magnetic fields: A Monte Carlo simulation study

N. Hajiloo$^1$

To assess beam deflection, longitudinal retraction, and depth-dose perturbation of therapeutic helium ion beams under transverse magnetic fields inside homogeneous and heterogeneous phantoms. Beam deflection, longitudinal retraction, and depth-dose perturbation of therapeutic helium ion beams under 0.35, 1.5, and 3 T transverse magnetic fields inside homogeneous phantom was assessed using the FLUKA Monte Carlo transport code. Besides that, the impact of a 3 T magnetic field presence on central axis depth-dose curves of 250 MeV/n helium ion beams inside a heterogeneous phantom with 3 cm thick air and bone layers was investigated. A 5.2 mm retraction and 36.1 mm deflection were observed for the helium ion beam in this study at 220.5 MeV/n energy and 3 T field. A 32.3% abrupt increase and 92.5% reduction in dose were observed at the boundary between the water-air and the water-bone layer insert, respectively. The presence of the magnetic field has an important impact on dose distribution of helium beams depending on the field strength and beam energy. Heterogeneous layers of air and bone leads to notable changes in the boundary of these layers with water under a 3 T magnetic field.

Classification of Diabetic Cardiomyopathy-Related Cells Using Machine Learning

U. Dalaman$^3$, S. Şengül Ayan$^1$, Y. Nazmi$^2$

The patch-clamp technique is a significant tool in current electrophysiology research, especially in cardiovascular diseases, because it can capture electrical activity of the heart from cardiomyocytes. It’s challenging to classify action potential waveforms in cardiological data from these recordings because it relies largely on professional assistance. We discovered that supervised classification may be used to predict the impact of electrophysiological perturbations on cardiomyopathic action potential groups in rat ventricular cells. At the cellular level, action potential classifications are utilized to discern between pathological and control waveforms in recorded cardiac action potentials. The three groups are control, diabetes with angiotensin, and diabetes with angiotensin. The signal’s biologically relevant features for the treatment of cardiomyopathy have been discovered. After they’ve been trained with different sets of features, the results of the seven machine learning models are compared. The k-nearest neighbor approach, along with the decision tree and random forest algorithms, is the best classifier for diagnosing aberrant action potential waveforms, with an accuracy of above 99 percent when compared to other models. The high classification accuracy demonstrates that the gathered individual cardiac AP features provide useful information regarding the pathological status of cardiomyocytes

A. M. Gordienko$^{1,2}$, A. A. Mozhaev$^{2,3,4}$, V. V. Gibizova$^1$, L. A. Dadinova$^2$

The Dps protein (DNA-binding protein from starving cells) is well known for its ability to protect cells from various negative factors, including oxidative stress. Dps is capable of rapidly oxidizing ferrous ions with hydrogen peroxide and then accumulating ferric ions in its cavity in the form of a ferric mineral. Dps is also able to bind to DNA forming highly ordered structures, becoming the most abundant stationary phase nucleoid protein, adding physical protection to chemical protection. In this work, anomalous small-angle X-ray scattering was first used to study the formation of iron clusters in the cavity of the Dps protein from Escherichia coli. On the basis of the created software using the known algorithm, the ASAXS curves were decomposed into resonant, non-resonant and cross components, which were subsequently used to calculate the average number of ions per protein molecule and determine the ab initio structure of the protein-iron complex. Using computer simulation methods, detailed information was obtained on the distribution of iron atoms inside the protein cavity at various concentrations of iron in solution. It has been shown that an increase in the concentration of Fe$^{2+}$ in solution has little effect on the morphology of the resulting iron mineral, but leads to an increase in its volume, which is in good agreement with the experimentally determined amount of iron ions per Dps molecule. The obtained values turned out to be less than the calculated values, which may be due to the presence of a chelating agent in the solution.

The Influence of Secondary Electron Emission on Surface Charging on a Mask Trench in Plasma Etching

D. Li, Z. Ma, P. Zhang

In the plasma etching technique, acquiring a high-quality transfer from the mask pattern onto the substrate under the suppression of the charging effects is of great significance. For a porpuse of comprehending the interplay of the surface charging with the secondary electron emission (SEE) on the the profile evolution of a mask trench during the plasma etching process, a classical particle simulation program is used by this study. The SEE module which utilizes a sophisticated Monte Carlo (MC) model was employed in the simulation. This study shows that the SEE contributes to a strengthened surface charging compared to the case without SEE. Specifically, in case of SEE being included, the scattering behavior of energetic electrons inside the mask can generate lots of cascaded electrons, leading to amounts of negative charges deposited in the solid. This is quite different from the case without SEE, which electrons only deposited on the surface and without any cascaded electrons being generated. Such difference causes the different electric field (E-field) strength distribution between these two cases (strength with SEE is higher than that without SEE). The simulation of the profile evolution further confirmed that the deformation is in keeping with the distribution of the E-field. In addition, there is an obvious edge effect can be observed in the case with SEE, which should alleviate the ions bombardment in principle, while the fact is not. Possible mechanisms behind have been discussed in detail. Because the electron scattering capacity is quite different in various materials, the implication of the current work helps to arrange an appropriate mask to reduce the damages from charging. This would shed light on a way to maintain the pattern integrity.

G. I. Andreev$^1$, V. L. Bychkov$^1$, V. P. Shevelko$^2$

In this paper, an experiment is analyzed in which an arc discharge in argon is ignited between a carbon cathode and an anode. Argon is supplied to the discharge combustion region, limited by a quartz cylinder. The light from the arc discharge passes through the light filter and focuses on the optical fiber, through which it is transmitted to the spectrometer. Spectrum analysis showed that the temperature in the arc is 9800 K. The concentration of plasma components is calculated based on the Saha equations for atoms, electrons, ions Ar I and Ar II. It turned out that the main plasma particles in the experiment are Ar I.

Benchmark Comparisons of OpenMC and DRAGON5 Codes for Calculating the Doppler Coefficient of Reactivity

J. Al-Zain$^{1,2}$, O. El Hajjaji$^2$, T. El Bardouni$^2$, M. Lahdour$^2$, M. Mira$^2$, H. Satti$^2$, H. El Yaakoubi$^2$

The new Version VIII.0 of the ENDF/B nuclear data library (ENDL) provided by the Los Alamos National Laboratory (LANL) in the United States was used to create a data set in ACE (A Compact ENDF) format and convert them to an HDF5 format for use in code OpenMC, at different temperatures of 600 and 900 K. Because of its importance within the nuclear simulation, the NJOY2016 code was utilized to develop a set of numerical benchmarks for the Doppler temperature coefficient (DTC) of reactivity. The eigenvalues of some selected idealized Light Water Reactor (LWR) pin cell configurations with seven different uranium fuel enrichments (0.711-5.0 wt\% $^{235}U$) were computed using the multi-group energy OpenMC Monte Carlo code. Two fuel temperatures (FT) corresponding to the hot zero power (HZP at 600K) and the hot full power (HFP at 900K) conditions have been considered. These benchmarks were provided for the evaluation of the precision of light water reactor codes for computing the system eigenvalue as well as the Doppler coefficient of reactivity. The results of the calculations were compared using the Monte Carlo OpenMC with the deterministic code DRAGON5. The two codes show good agreement when compared to previous studies.

M. I. Propoy$^1$, F. B. Hlebnikov$^1$, D. A. Konyaev$^{1,2}$, N. E. Shapkina$^{1,2}$, A. N. Bogolubov$^1$

The problem of modeling an electromagnetic field reflected from a cylindrical mirror collimator with a complex symmetrical or asymmetrical cross-section is considered. The problem is solved for different frequencies and polarizations of the incident wave with various geometric parameters of the mirror, including the parameters of the rounded edges. Additionally, the problem of synthesis of the parameters of the mirror edges for both one and numerous frequencies of the incident wave is considered.

A. A. Lagutina$^{1,2}$

Optical monitoring of the deposition process of multilayer coatings can lead to a correlation of errors in the thicknesses of the deposited layers. This effect, in turn, can lead to an accumulation of errors, but at the same time, it can have a positive effect if there is an error self-compensation effect. The previously developed methods for estimating the degree of error correlation in layer thicknesses and assessing the presence of the self-compensation effect, which include the results of processing a large number of computational experiments, open up new possibilities for comparing existing monitoring strategies. On the example of a computer simulation of the deposition process of a 44-layer hot mirror, it is shown how the above estimates can be used to compare the effectiveness of various monitoring strategies.

A. V. Smirnov$^1$, A. A. Kurganskaya$^2$, I. A. Ovchenkova$^1$, A. E. Bogdanov$^1$, A. V. Morozkin$^3$, I. S. Tereshina$^2$, S. A. Nikitin$^1$

Magnetization measurements and direct measurements of the magnetocaloric effect in intermetallides based on Gd$_5$Si$_2$Ge$_2$ with small substitutions of silicon (Si) and germanium (Ge) atoms with tin (Sn) and indium (In) atoms were carried out. It was found that the introduction of Sn decreases and the introduction of In increases the temperature of the magnetic ordering of these intermetallides relative to the Curie temperature of the initial compound Gd$_5$Si$_2$Ge$_2$. The magnitude of the magnetocaloric effect does not noticeably change with the substitutions of p-elements made. The difference in the magnetic properties of the initial compound Gd$_5$Si$_2$Ge$_2$ and compounds with substitutions Gd$_5$Si$_{2-x}$Ge$_{2-x}$(Sn, In)$_{2x}$ (x = 0.05) is explained by the electronic structure of the doping atoms and the change in the density of electronic states at the Fermi level.

S. G. Zheltoukhov$^{1,2}$, A. M. Tatarnikov$^{1,2}$

The main factors influencing the success of observations in the infrared (central wavelengths of the photometric bands 3.75 and 4.8~µm) on the universal optical telescope are considered. We obtained estimates of the sky background brightness for the Caucasus Mountain Observatory of Moscow State University (CMO): $1.3\cdot10^6$ photons/(s$\cdot$pixel) in the 3.75~µm band and $3.4\cdot10^6$ photons/(s$\cdot$pixel) in the 4. 8~µm; and instrumental background for the 2.5-m KGO telescope at $0^\circ$C: $3.2\cdot10^6$ photons/(s$\cdot$pixel) in the 3.75~µm band and $4.3\cdot10^6$ photons/(s$\cdot$pixel) in the 4.8~µm band. It is shown that at this background level with the currently available commercial cameras for 3-5~µm spectral range, the capability of the telescope+camera combination to observe faint objects will still be limited by the thermal background. For different observational conditions, we have obtained estimates of the limiting magnitudes of objects accessible to observations in the 3.75 and 4.8~µm bands. For the case of average observing conditions (instrument temperature $0^\circ$C and stellar image size $1''$), the limit is $\sim10.6^m$ and $\sim8.4^m$, respectively.