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About this book

This book gathers the proceedings of the 4th International Conference on Nanotechnologies and Biomedical Engineering, held on September 18-21, 2019, in Chisinau, Republic of Moldova. It continues the tradition of the previous conference proceedings, thus reporting on both fundamental and applied research at the interface between nanotechnologies and biomedical engineering. Topics include: developments in bio-micro/nanotechnologies and devices; biomedical signal processing; biomedical imaging; biomaterials for biomedical applications; biomimetics; bioinformatics and e-health, and advances in a number of related areas. The book offers a timely snapshot of cutting-edge, multidisciplinary research and developments in the field of biomedical and nano-engineering.

Table of Contents

Frontmatter

Nanotechnologies and Nanomaterials

Frontmatter

3D-Printed Sensor Array of Semiconducting Oxides

Sensors start to play an ever increasing role in human life and new technologies for their cost-effective mass production are required. In this work, the one-step 3D-printing of nanoflakes—nanowire covered Fe2O3/Fe–CuO/Cu2O/Cu microparticles (MPs) with diameters of ~10 µm on the surface of glass substrate successfully forming an ordered net is reported for the first time. 3D-printed Fe–Cu and only Cu MPs-based stripes formed non-planar CuO/Cu2O/Cu and Fe2O3/Fe–CuO/Cu2O/Cu heterojunctions after thermal annealing at 425 ℃ for 4 h in air and were fully covered with nanoflakes of Fe2O3 and CuO nanowire net bridging MPs with external Au-contacts. The morphological, chemical and structural investigations were performed in detail, showing the high crystallinity of the 3D printed material. This concept proves to be easily translatable to other semiconducting, metallic or functional microparticles for the rapid fabrication of sensor devices.

L. Siebert, M. I. Terasa, N. Ababii, O. Lupan, R. Adelung

Broad-Band Spectroscopy of Nanoconfined Water Molecules

We have performed broad-band spectroscopic investigations of vibrational and relaxational excitations of water molecules confined to nanocages within artificial beryl and mineral cordierite crystals. Signatures of quantum critical phenomena within the H2O molecular network are registered in beryl. In cordierite, a density functional analysis is applied to reconstruct the potential energy landscape experienced by H2O molecules, revealing a pronounced anisotropy with a potential well of about 10 meV for the molecular dipole moment aligned along the b-axis. This anisotropy leads to a strongly temperature dependent and anisotropic relaxational response of the dipoles at radiofrequencies with the activation energies corresponding to the barriers of the rotational potential. At T ≈ 3 K, we identify signatures of a transition into a glassy state composed by clusters of H2O dipoles. Rich set of anisotropic and temperature-dependent excitations are observed in the terahertz frequency range which we associate with rotational/translational vibrations.

M. A. Belyanchikov, M. Savinov, Z. V. Bedran, P. Bednyakov, P. Proschek, J. Prokleska, V. I. Torgashev, E. S. Zhukova, S. S. Zhukov, L. S. Kadyrov, V. Thomas, A. Dudka, A. Zhugayevych, V. B. Anzin, R. K. Kremer, J. K. H. Fischer, P. Lunkenheimer, A. Loidl, E. Uykur, M. Dressel, B. Gorshunov

Superposition States of the Two-Dimensional Magnetoexcitons with Dirac Cone Dispersion Law and Quantum Interference Effects in Optical Transitions

The exchange electron-hole (e-h) Coulomb interaction changes essentially the properties of the two-dimensional (2D) magnetoexcitons, whose electron structure is mainly determined by the action of the Lorentz force and by the direct e-h Coulomb interaction. The exchange interaction leads to the mixing of the two bare magnetoexciton states with total angular momentum projections $$ F = \pm 1 $$ F = ± 1 . As a result instead of them two new superposition states one symmetric and another asymmetric appeared. The symmetric state acquired a Dirac cone dispersion law in the range of the small in-plane wave vectors $$ |\vec{k}_{||} |l_{0} < 1 $$ | k → | | | l 0 < 1 , where $$ l_{0} $$ l 0 is the magnetic length, with group velocity proportional to the magnetic field strength. The quantum transitions to this state from the ground state of the crystal under the influence of the light with both circular polarizations have the equal probabilities, being strongly dependent on the direction of the light propagation as regards the plane of the layer. The probability is maximal in the Faraday geometry and vanishes in the Voigt one. In difference on it, the asymmetric state is characterized by the usual dispersion law inherited from the bare magnetoexciton states, is dipole active in both circular polarization, but does not depend on the direction of the light propagation. In the case of light with linear polarizations the both symmetric and asymmetric states reveal the quantum interference effects.

S. A. Moskalenko, I. V. Podlesny, I. A. Zubac, B. V. Novikov

Superconductivity and Weak Ferromagnetism in Inclination Bicrystal Interfaces of Bismuth and Antimony

Using Quantum Design SQUID magnetometer and Physical Property Measuring System (PPMS), we studied the magnetic and superconducting properties of high-quality inclination crystallite interfaces (CIs) of bicrystals of Sb and Bi. It was found that the CIs with a higher carrier density than single crystalline samples exhibit a superconducting transition with respectively Tc ≤ 10 K for Sb and Tc ≤ 21 K for Bi interfaces; the Sb CIs also manifest ferromagnetic hysteresis loops against a paramagnetic background, thereby indicating occurrence of superconductivity and weak ferromagnetism.

F. M. Muntyanu, K. Nenkov, A. J. Zaleski, V. Chistol

Unusual Size Dependence of Acoustic Properties in Layered Nanostructures

Compared to symmetrically stacked layered structures, e.g., sandwich-like, much less is known about acoustic properties in a more general configuration lacking such a symmetry. Structures composed of layers with different characteristics (e.g., metal-insulator) are ubiquitous in nanotechnologies harnessing finite size and quantum effects. Explicit analytic expressions describing acoustic waves in a representative two-layer system are derived and analyzed in the full space of material parameters. An unusual behavior of the spectrum is revealed in the dispersive (long wavelength) region where size effects are most prominent. Velocity of the lowest frequency branch, which becomes the Rayleigh surface wave at shorter wavelengths, is shown to depend in a strongly non-monotonous way on the thickness of the layers in contrast with the expected monotonous evolution of higher frequency branches. The wave pattern of different mode types is discussed in detail. Connection between long (including resonances of the composite plate) and short wavelength (bulk-like, surface and interface guided) regions of the spectrum is established. It is shown that the peculiar behavior of the low energy phonon spectrum induces similar effects in the electron-phonon relaxation and heat transport in composite nanomaterials at low temperatures.

S. Cojocaru

Features of Radiative Recombination of Iron-Doped Gallium Antimonide

We report on the results of the studies of the features of radiative recombination of iron-doped gallium antimonide at T = 2 K, in the absence of an external magnetic field. Specimens were prepared by a modified method of zone melting. The concentration of iron incorporated in the melt varied in the range of 0.001–3 (atomic percent). The studied specimens exhibited p-type conductivity. It was demonstrated that in gallium antimonide iron created a shallow acceptor level with the ionization energy of (22 ± 0.2) meV. In addition, the structure of the radiative recombination spectra was determined and the concentration of radiative centers was found out.

A. Mihalache

Spin Crossover in Iron(II) Complexes with Mixed Nitrogen-Sulfur Coordination: DFT Modeling

The majority of known FeII spin crossover (SCO) complexes are based on a homogeneous octahedral nitrogen coordination of the metal ion. Currently a new type of compounds with mixed nitrogen-sulfur ligand surroundings of the iron(II) ions demonstrating spin transitions has attracted much attention. Despite the comprehensive experimental characterization the origin of SCO phenomena in these complexes has not been elucidated. In the present paper on the basis of DFT calculations we describe the course of the spin transformation in the γ-polymorph of the [Fe(bpte)(NCSe)2] compound containing in the unit cell two different types of iron(II) ions which differ in the geometry of the {N4S2} ligand surroundings. To prove the adequacy of the suggested approach in the present paper the well known picture of SCO in the thoroughly characterized classic [Fe(ptz)6](BF4)2 compound is also reproduced.

S. I. Klokishner, O. S. Reu

Change in Microstructure and Magnetic Properties of Transition Metal Nitride Thin Films by Substrate Temperature

The magnetic and mechanical properties of transition metal nitrides can be altered in many ways by their composition and microstructure, thus giving them excellent usability for spintronics and corrosion resistant coatings. The production of binary and ternary nitride thin films by reactive sputter deposition provides a wide variety of unique material combinations. This study shows the considerable influence of the substrate temperature on microstructure and magnetic properties for different nitride compounds (Fe–N, Ni–N, Fe–Ni–N, and Fe–Al–N). The substrate temperature is found to be a significant parameter which allows adjusting the phase formation and magnetic properties from soft ferromagnetic to superparamagnetic. Furthermore, the extent and incidence of texturing as well as the transition from poly- to monocrystalline thin films can be controlled.

M. Kamp, L. Voß, T. Bichel, M. Hicke, U. Schürmann, L. Kienle

Modeling of Charge Transfer Induced Spin Transition in a Linear {FeCoFe} Complex

The magnetic behavior of the {[FeTp(CN)3]2Co(Meim)4} · 6H2O compound is examined. Since the observed charge transfer induced spin transition in this compound is accompanied by electronic density redistribution, the theoretical model includes the electron transfer between the Fe and Co ions and two types of cooperative interactions, namely, the electron-deformational and dipole-dipole interactions. It is demonstrated that at low temperatures the spin transformation in the compound under study is accompanied by the appearance of macroscopic polarization. The developed model gives a quite good explanation of the observed effective magnetic moment.

S. M. Ostrovsky, S. I. Klokishner

Mössbauer Effect in 57Fe-Doped Gallium Antimonide

The work offers for discussion the results of investigations of absorption spectra (gamma-ray nuclear resonance) of gallium antimonide doped with 57Fe isotope in the concentration range of the atomic mass of 1–3%, within the temperature range of 4.2–300 K, in the absence of an external magnetic field. Also, a model of the impurity center of iron in gallium antimonide is described.

A. Mihalache

ZnO Nanometric Layers Used in Photovoltaic Cells

The ZnO thin layers were grown on glass, InP and pInP-nCdS substrates from zinc acetate dissolved in water-acetic acid-methanol solution having a molarity of 0.2 M by using the spray method in the argon flow in the temperature range of (250–450) °C. The dependence of optical properties of ZnO layers on growth temperature have been investigated. The optical transmittance has values of 80–85% in the wavelength range of (200–1000) nm. The using of ZnO of the thickness of (60–80) nm as antireflective layers in nCdS-pInP structures allowed to increase the photovoltaic cell efficiency by 3%. The photosensitivity of the fabricated nZnO-pInP structures covers the wavelength region from 450 nm up to 1100 nm and allows the more efficient utilization of the incident light.

V. Botnariuc, L. Gorceac, A. Coval, B. Cinic, P. Gaugas, P. Chetrus, I. Lungu, S. Raevschi

Resistivity Response to Stress and Strain of a Flexible Bi2Te3 Based Thermoelectric Material

Here we report about the synthesis of Bi2Te3 based flexible thermoelectric materials and the response of the electrical resistivity to tensile and compressive stress. As a template fiber spun polymers have been used onto which a thin composite film of graphene and Bi2Te3 nanoplates was deposited. The Bi2Te3 nanoplates were synthesized using the polyol method. Upon straining the material, the resistivity dropped which is attributed to the increased contact between the individual wires.

L. O. Akinsinde, S. Scheitz, L. Zimoch, J. K. Sierck, L. Siebert, R. Adelung, U. Schürmann, M. A. Rübhausen, T. Dankwort, L. Kienle

“True” Dose Rate Effect of the ELDRS Conversion Model

Modification of the ELDRS (Enhanced Low Dose Rate Sensitivity) conversion model is presented. The effect of the oxide trapped charge on the value of the oxide electric field and the yield of the oxide charge takes into account. It leads to dependence of the accumulation of radiation-induced oxide charge and interface traps on the dose rate. In enhancement version the ELDRS conversion model describes the low dose rate effect as “true” dose rate effect.

V. S. Pershenkov, A. S. Bakerenkov, V. A. Telets, V. V. Belyakov, V. A. Felitsyn, A. S. Rodin

Modeling of the Valence Tautomeric Transformation in Heterometallic [Cr-Dhbq-Co] Molecules

In the present communication we report a model that describes the valence tautomeric transformation in a crystal consisting of heterometallic [Cr-dhbq-Co] molecules. The model takes into account the states arising from two different configurations of the molecule, namely, Cr3+-dhsq3−-Co3+ and Cr3+-dhsq2−-Co2+, the Heisenberg exchange interaction between the dhsq3− ligand and the Cr3+ ion as well as the cooperative electron-deformational and dipole-dipole interactions. The problem is solved in the mean field approximation. The main peculiarities of the valence tautomeric transformation are elucidated. It is demonstrated that the electron transfer ligand-Co is accompanied not only by the significant increase of the effective magnetic moment but also by the appreciable change in the microscopic polarization. The model provides quite a good description of the experimental data on the temperature dependence of the effective magnetic moment in the [(Cr(SS-cth))(Co(RR-cth))(μ-dhbq)](PF6)3 compound.

M. A. Roman, S. I. Klokishner

Fabrication and Application of TEM-Compatible Sample Grids for Ex Situ Electrical Probing

Memristors are promising candidates for new memory technologies and are capable to mimic neural networks. The switching in memristive devices occurs typically in few nanometer thin oxide layers. The direct observation of the switching mechanism is crucial for better comprehension and improvements of memristors. Therefore, in situ experiments are conducted in a transmission electron microscope (TEM). However, electron beam irradiation can lead to a chemical modification of the active layers. Moreover, devices may show different performance due to the details of processing parameters. Thus, it is essential to characterize memristors electrically before microstructural analysis. In this work a TEM compatible grid is developed, which can be used for ex situ electrical probing and TEM investigations. Different techniques for the production, like shadowing and lithography are compared with their advantages and drawbacks.

O. Gronenberg, N. Carstens, A. Vahl, F. Faupel, L. Kienle

Refractive Index in the Region of Excitonic Resonances in TlGaSe2 Crystals

The low-temperature transmission and wavelength modulated transmission spectra of TlGaSe2 crystals with a thickness of 7, 5.7, 4.7 μm were measured. Refractive index was calculated from interference observed in transmission spectra. The spectral dependences of the normal dispersion na (E║a) and nв (E║в) and Δn = na (E║a) − nв (E║в) on the long-wavelength and short-wave side of the ground states A, B and C of excitons are determined.

A. V. Tiron

Optical Activity in Mn Doped As2S3 Glasses

Spectral dependences of transmittance (T) and wavelength modulated transmittance (ΔT/Δλ) of As2S3 layers doped by manganese (Mn) of different concentrations (0–0.5%) were investigated at temperatures from 10 to 300 K. Photoluminescence bands at 1.762, 2.107 and 2.282 eV due to transition 4A2g(4F) ⟶ 4Eg(2G), 4T1g(4G) ⟶ 6A1g(4F) and 4T2g ⟶ 6A1g of Mn ions, respectively were observed at argon laser excitation. On the luminescence spectra the absorption bands of electron transitions 6A1g(4F) ⟶ 4T1g(4G) were recognized. The magnitude of refractive index (n) of Mn (0.1 and 0.5%) ions doped As2S3 layers in low-energy range (1.6–1.9 eV) does not change at temperature decreasing from 300 to 10 K. The spectral dependences of refractive indices of As2S3 samples doped with Mn ions of different concentrations (0.1 and 0.5%) did not have any features.

V. V. Zalamai, A. V. Tiron, M. S. Iovu, N. N. Syrbu

Electrical Properties of Thermal Annealed in Vacuum Spray Deposited Al-Doped ZnO Thin Films

Al-doped ZnO thin films have been prepared by spray pyrolysis, which facilitates the incorporation of a higher percentage of dopant atoms. The vacuum thermally annealed at 420 °C temperature thin films have been characterized by X-ray diffraction (XRD), optical spectroscopy. Electrical conductivity and the Hall effect are investigated in the temperature interval (77–300) K. X-ray analysis results reveal that all the films are polycrystalline with a hexagonal wurtzite structure with a preferential orientation according to the direction (002) plane. Different characters of the temperature dependence of conductibility are observed in the Al-doped ZnO films vacuum thermally annealed at 420 °C temperature. In all cases, the conductivity, mobility carriers and carriers’ concentration of ZnO thin films obtained under Ar are higher than under O2 atmosphere, unless they are not doped. of your paper no longer than 300 words.

T. Potlog, I. Lungu, S. Raevschi, V. Botnariuc, S. Robu, S. Worasawat, H. Mimura

Growth of P-GaN on Silicon Substrates with ZnO Buffer Layers

GaN layers on Silicon with ZnO intermediate layer were synthesized by using the HVPE (Hydride Vapor Phase Epitaxy) method. ZnO layers were deposited from solutions of zinc compounds in ethanol or water in two steps. At the first step a ZnO nucleation layer was deposited from a solution of zinc acetate in ethanol, at the second step a ZnO precipitate was deposited from a solution of zinc nitrate and KOH in water by boiling. On the obtained structures the GaN nucleation layers were deposited at 500 ℃ for 15 min, then GaN layers were grown at 850–970 ℃ for 30 ± 5 min. Structures were studied by using the optical and SEM microscope and XRD method. The type of conductivity of the layers was determined by using the method of thermal electromotive force measurement (TEFM). The possibility of the electrical conductivity (EC) type changing from n- to p-type for the GaN layers deposited on silicon substrates with the use of intermediate ZnO layer deposited from solutions is demonstrated for the first time.

S. Raevschi, L. Gorceac, V. Botnariuc, T. Braniste

TEM and Electrochemical Investigation of Different Morphology Silicon Anodes

The volumetric changes and the structural deterioration in Silicon anodes during successive electrochemical lithiation/delithiation cycles limits the utilization of Silicon (Si) anodes in Lithium-based batteries. However, using morphologically modified Si and suitable conducting additives can ensure better electrochemical performance and structural stability even after repeated electrochemical cycles. This research is aimed at comparing the electrochemical performance and solid electrolyte interface (SEI) of different Si anode geometries i.e. powdered Si and Si microwires after cycling. The SEI is analyzed using Transmission Electron Microscope (TEM) methods after cycling in the electrochemical half cell. Si microwires show relatively superior electrochemical performance compared to the powdered Si.

K. Saleem, U. Schürmann, S. Hansen, H. Cavers, R. Adelung, L. Kienle

Adsorption of Lead Ions on Carbonaceous Sorbents of Nutshell Obtained from Secondary Raw Material

The sorption of Pb (II) ions from an aqueous solution of lead nitrate on carbon sorbents, obtained from waste based on cellulose-containing materials, was studied. Particularly, among studied carbons [hazel nutshell, walnut shell, sawdust, activated carbon (fraction size—40 μ)] material obtained from walnut shell shows the best adsorptive properties. The possibility of their use for the purification of drinking and waste waters contaminated with lead ions is established. The maximum amount of lead that can be bound by 1 g of sorbent is 154.0 mg/g, while 95% of metal ions are bound within 30–40 min.

T. Marsagishvili, G. Tatishvili, N. Ananiashvili, N. Giorgadze, E. Tskhakaia, M. Gachechiladze, J. Metreveli, M. Machavariani

Structural and Photoluminescence Properties of Nanoparticles Formed by Laser Ablation of Porous Silicon in Ethanol and Liquid Nitrogen

Sequential use of electrochemical etching and picosecond laser ablation in ethanol and liquid nitrogen allows fabrication of silicon particles with size smaller than 100 nm and high level of crystallinity. Fabricated ensembles of nanoparticles exhibit effective photoluminescence with emission peaks located within biotissue optical transparency window, thus being promising as contrasting agents for bioimaging.

A. V. Skobelkina, F. V. Kashaev, S. V. Zabotnov, A. V. Kolchin, T. P. Kaminskaya, D. E. Presnov, E. A. Sergeeva, M. Yu. Kirillin, L. A. Golovan, P. K. Kashkarov

Electrical and Photoelectrical Properties of Zn1−xMgxO Thin Films Obtained by Spin Coating and Aerosol Deposition Method

Zn1−xMgxO thin films were prepared by aerosol deposition and spin-coating method, using zinc acetate and magnesium acetate as precursors. The obtained films were investigated by scanning electron microscopy (SEM), electrical and photoelectrical characterization. SEM and energy dispersive x-ray (EDX) analysis has shown that the produced thin films are homogeneous in morphology and composition. The relaxation of photoconductivity under UV illumination was investigated in vacuum as a function of temperature. It was found that the thin films produced by spin-coating exhibit much higher photosensitivity and long duration relaxation of photoconductivity, in contrast to the films obtained by aerosol deposition. The investigation of photosensitivity in a wider spectral range demonstrated that the films are also sensitive to the visible and infrared irradiation.

V. Morari, V. Postolache, G. Mihai, E. Rusu, Ed. Monaico, V. V. Ursachi, K. Nielsch, I. M. Tiginyanu

Peculiarities of Surface Relief Grating Formation in Nanomultilayer Structures Based on As2S3–Se Chalcogenide Glasses

Chalcogenide glasses nanomultilayer structures based on As2S3–Se were used for direct surface relief grating (SRG) formation by holographic recording. Grating recording process in As2S3–Se nanomultilayer structure for different grating period and long recording time was performed. Simulated diffraction efficiency kinetics curves showed good agreement with the experimental results Analyses of diffraction efficiency kinetics and AFM images of recorded SRG showed that grating period increasing led to the SRG depth increasing in linear way. It was revealed that SRG recording rate was characterized by non-linear behavior, while modulation depth remained approximately the same value for all gratings.

A. Meshalkin, O. Paiuk, E. Achimova, A. Stronski, V. Abaskin, A. Prisacar, G. Triduh, A. Korchovyi, P. Oleksenko

Near-Edge Optical Properties of Layered Tin Sulfide (Selenide) Crystals

Absorption (K), reflection (R) and wavelength modulated transmission (ΔT/Δλ) spectra in SnS, SnS2 and SnSe crystals were investigated in temperature range from 300 to 10 K. Excitonic states were discovered in all investigated compounds. Parameters of observed excitons and character of electron transitions participating in absorption edge formation were determined. Optical anisotropy in interband gap minimum was investigated.

V. V. Zalamai, A. V. Tiron, E. V. Rusu, E. V. Monaico, N. N. Syrbu

Nanostructured Organic Crystals as Prospective Thermoelectric Materials for Infrared Sensors

In this paper we investigate the prospective of use of some nanostructured organic crystals as efficient thermoelectric material for infrared biosensors. Nowadays, the infrared sensors are widely implemented in thermal imaging system, night vision systems and different personal or clinical devices for health monitoring. A thermoelectric sensor consists of thermocouples of n-type and p-type materials with high electrical conductivity. The sensitivity of the sensor is determined mainly by the thermoelectric power factor of the material. Quasi-one dimensional organic crystals of tetrathiotetracene-iodide, TTT2I3 of p-type and tetrathiotetracene—tetracyanoquinodimethane, TTT(TCNQ)2 of n-type were proposed earlier as prospective materials with high thermoelectric power factor. In the following, the electrical conductivity, the Seebeck coefficient and the thermoelectric power factor of TTT2I3 crystals are calculated numerically as a function of temperature. The optimal values of charge carrier concentration in order to achieve a high thermoelectric power factor are determined.

I. I. Sanduleac, S. C. Andronic, A. I. Casian

Effects of Green Silver Nanoparticles on CCl4 Injured Albino Rats’ Liver

Nanoparticles green synthesis by plants and extracts is very cost-effective and can be used as an economic and environment friendly alternative in large-scale production. But the effect of these structures on the liver isn’t fully investigated. In this study green silver nanoparticles (AgNPs) were synthesized by O. araratum 50% ethanol extract that has the highest antiradical activity. It was found that treatment by O. araratum extract leads to rats’ liver structure normalization and normalization of liver injury markers’ activity. Meanwhile, AgNPs at 20 mg/kg body weight dose leads to fibroblasts activation and fibrosis.

Sh. Kazaryan, M. Petrosyan, L. Rshtuni, V. Dabaghyan, A. Hovhannisyan

Luminescent Properties on ZnO:Cr Nanocrystals and Thin Layers

Both undoped and chromium doped zinc oxide nanocrystal powders are obtained by chemical deposition and hydrothermal methods. ZnO and ZnO:Cr thin layers on the surface of ZnSe and ZnSe:Cr samples, respectively, are obtained by isovalent substitution of selenium by oxygen in the process of thermal treatment of the samples in air. Photoluminescence spectra of the ZnO and ZnO:Cr nanopowders and thin layers obtained by various techniques are investigated at room temperature. Cr doped ZnO powders obtained by chemical deposition and hydrothermal methods improves the powder quality, as evidenced exciton emission is more intensive. New emission bands are found in visible (615 nm, 625 nm) and infrared (925 nm, ~2000 nm) spectral ranges for ZnO:Cr nanopowders and thin films. The contribution of Cr impurity to the formation of emission bands is discussed.

T. Goglidze, I. Dementiev, E. Goncearenco, N. Nedeoglo, T. Iurieva, D. Nedeoglo

Evaluation of Stimulatory, Antifungal and Thermo-Resistant Action of Aqueous Dispersions of Nanoparticles on Seeds of Parental Forms and Reciprocal Hybrids of Winter Wheat

For the first time in the crop technology, the effect of aqueous dispersions of nanoparticles was investigated on seeds of parental forms and their reciprocal hybrids, making it possible to effectively use this factor in plant breeding and genetic practice. The received data can be used to select optimal pairs for crossing and obtain new promising hybrids. It was shown the stimulatory, antifungal and thermo-resistant action (increase of resistance to pathogenic fungus) of water dispersed solutions of silver and copper nano-particles on seeds of winter triticale. The antifungal effect of the nanofactor is more effective than of the potassium permanganate. In terms of seed germination energy and sprout length of winter wheat (parent varieties and their reciprocal hybrids) we revealed the stimulatory and antifungal action of aqueous dispersions of silver, copper, bismuth, and zinc oxide nanoparticles on the seeds. The maternal effect is revealed—the primary influence of the maternal form on the physiological parameters of the hybrid.

S. N. Maslobrod, G. A. Lupashku, S. I. Gavzer, A. I. Gore, Yu. A. Mirgorod

Photocatalytic Degradation of Methylene Blue with Composite Nanocrystalline TiO2+ Diatomite

In this study photocatalytic activity of the prepared nano-sized TiO2-based composite was tested by decolorisation/degradation of Methylene blue (MB) as a model pollutant under UV illumination. The composite was synthesized by a modified heterogeneous hydrolysis method in the presence of diatomite suspension by using TiCl4 as titania precursor. The photocatalyst was found to be very active for the photocatalytic decomposition of MB in aqueous solution. The percent decolorization in 60 min was 98% with initial MB concentration 53 mg/L. The photocatalytic activity was correlated with physico-chemical properties of the synthesized materials. There is a synergistic effect of grafting titanium dioxide onto the surface of diatomite: the photocatalytic activity of TiO2 dispersed on the diatomite surface vas found to be much higher than of the bulk titania mainly due to the high surface area and uniform distribution of TiO2 on clay mineral avoiding aggregation.

T. Ya. Datsko, V. I. Zelentsov, D. P. Dvornikov

Micromechanical Properties and Plastic Deformation Features of the Pb1−xYbxTe Ternary Semiconductors

In this paper, the effect of ytterbium (Yb) impurity on the microstructure, the specificity of plastic deformation and the strength properties of PbTe crystals has been studied. The researches have been conducted on a PMT-3 microhardness tester using loads in the range (50–1000) mN. For all applied loads, the Pb1-xYbxTe (x = 0.0025; 0.0075 and 0.01 at.%) single crystals showed pronounced plasticity and very low hardness values (H = 0.35–0.39 GPa), which is characteristic of compounds containing lead. It was suggested that the deformation of Pb1−xYbxTe crystals under microindentation occurs by a dislocation mechanism with some contribution of the structure compaction in the bulk beneath the indentations.

D. Z. Grabco, V. Z. Nicorici, Z. A. Barbos, D. Topal, O. A. Shikimaka

Quantum Interferences with Equidistant Three-Level Quantum Wells

A three-level ladder-type equidistant quantum-well with perpendicular transition dipoles, tuned in resonance with an optical cavity have been investigated in the good cavity limit. Under the laser pumping, a quantum interference phenomena occurs. This phenomenon is controlled via the laser intensities and phases and may be tuned in order to destructively interfere. The cavity mean photon number vanishes under these conditions.

V. Ceban, M. A. Macovei

Luminescence Properties of a Novel Eu3+ Dinuclear Coordination Compound

The paper presents experimental results on a novel Eu3+ dinuclear coordination compound [Eu(µ2-OC2H5)(NO)3(phen)]2·phen with high emission quantum yield. The complex has been characterized by photoluminescence (PL) spectroscopy. The absolute PL quantum yield, and the sensitization efficiency were determined to be 49.2% and 78.7% respectively.

V. I. Verlan, I. P. Culeac, O. Bordian, V. E. Zubareva, I. Bulhac, M. S. Iovu, M. Enachescu, N. A. Siminel, V. V. Nedelea

Me-ZnP2 Diodes Sensible to Optical Gyration

Spatial dispersion in ZnP2-D 4 8 has been studied. The spectral dependences of the refractive index nc(Eǁc, kǁa), na(Eǁa, kǁc) and nb(Eǁb, kǁc) had been determined. It was shown that the dispersion is positive nc(Eǁc, kǁa), na(Eǁa, kǁc) > nb(Eǁb, kǁc) in λ > λ0 region, the dispersion is negative nc(Eǁc, kǁa) at λ < λ0, and Δn = nc – nb= 0 at λ = λ0. The LIV characteristics of Me-ZnP2-D 4 8 diodes had been studied at different temperatures, the temperature dependences of the “imperfection” factor δ for different Schottky barriers. Capacitance voltage characteristics of Me-ZnP2-D 4 8 photodiodes obtained by electrochemical deposition of metal and by thermo-chemical spraying in vacuum had been studied. The influence of birefringence and gyration on spectral characteristics of p-n photodiodes and Schottky diodes had been revealed. The ability of controlling photodiodes’ characteristics was obtained using the gyration particularities in ZnP2-D 4 8 crystals.

A. V. Dorogan, S. I. Beril, I. G. Stamov, N. N. Syrbu

Applications of Chalcogenides as Electron Transport Layers and Doping Materials in Perovskite Solar Cells

The work contains the experimental results obtained by applying of ZnS and ZnSe thin films in perovskite solar cells. The techniques of preparing and researching the electrical properties of the obtained devices have been described in details.

M. E. Popa

Applications of Chalcogenides as Hole Transport Layers and Dopants in Perovskite Solar Cells

In the work are presented the experimental results obtained by applying ZnTe as a hole transport layer and as a dopant in perovskite solar cells with inverted planar architecture.

M. E. Popa

The Influence of the External Magnetic Field on the Electronic Density of States of Quasi-1D System in the Mixed Phase of Superconductivity and Spin Density Wave

A method for calculating the electronic density of states in the mixed phase: superconductivity (SC) and the magnetic state of the spin-density wave (SDW) is proposed. The main mechanism for the appearance of this phase is considered the doping of the system and allowance for the lattice structure (Umklapp processes). The effect of an external magnetic field and the possibility of increasing the superconducting transition temperature Tc are analyzed.

M. E. Palistrant, I. D. Cebotari, S. A. Palistrant

Elastic Coupling at Epitaxial Multiferroic Interfaces: In Situ X-Ray Studies of Electric Field Induced Strain

The elastic coupling in multiferroic materials and even more so in magnetoelectric composites plays an important role for the properties and function. In this study, the electrically induced strain at the epitaxial interface of 0.72Pb(Mn1/3Nb2/3)O3–0.28PbTiO3—CoFe2O4, a magnetoelectric composite, is characterized by in situ X-ray scattering experiment and transmission electron microscopy study. For the measured range all strain induced lattice changes are reversible ruling out plastic deformation. The surprisingly non-perfect elastic coupling of 87 ± 7% in this epitaxial system can be explained by the presence of planar defects in the CFO film.

C. T. Koops, S. B. Hrkac, M. Abes, P. Jordt, J. Stettner, A. Petraru, H. Kohlstedt, V. Hrkac, N. Wolff, L. Kienle, O. H. Seeck, G. Nisbet, O. M. Magnussen, B. M. Murphy

Investigation of the Electrochemical Properties of Lithium–Sulfur Cells with Sulfur Electrodes Based on Carbon Inverted Opals

Carbon structures with an inverted opal lattice was synthesized. Comparative studies of the electrochemical properties of lithium–sulfur cells with sulfur electrodes based on the samples and other carbon materials have been carried out. The synthesized material showed a good stability when cycling in the range of more than 300 cycles. That says about the prospects for the use of such structures in lithium–sulfur batteries.

N. S. Sukhinina, E. V. Karaseva, V. M. Masalov, E. V. Kuzmina, A. A. Zhokhov, V. S. Kolosnitsyn, G. A. Emelchenko

Peierls Structural Transition in Organic Crystals of TTT2I3 with Intermediate Carrier Concentration

The Peierls structural transition in the nanostructured tetrathiotetracene-iodide crystal with intermediate carrier concentration is studied in 2D approximation. In the frame of the physical model, two the most important electron-phonon interactions are considered: of the deformation potential type and of the polaron type. The interaction of carriers with the structural defects is also taken into account. The renormalized phonon spectrum is calculated in the random phase approximation. The method of retarded temperature dependent Green function is applied. It is shown that the transition is of Peierls type and strongly depends on iodine concentration.

S. C. Andronic, I. I. Sanduleac, A. I. Casian

GaN-Based 2D and 3D Architectures for Electronic Applications

In this paper we demonstrate the fabrication of electronic devices based on GaN nanostructures. For fabrication of 2D and 3D GaN nanostructures, Surface Charge Lithography (SCL) and Hydride Vapor Phase Epitaxy (HVPE) techniques were used. A memristor device based on GaN ultrathin membranes with the thickness of 15 nm obtained by SCL was elaborated. For GaN microtetrapods growth, the HVPE method was used, where ZnO microtetrapods were used as sacrificial template. Because of the high temperature in the reactor and presence of hydrogen gas, ZnO is decomposed, resulting in the formation of ultra-porous hollow GaN microtetrapods. A hydrostatic pressure sensor based on GaN hollow microtetrapods with the wall thickness of 80 nm covering the pressure interval up to 40 atm was fabricated and characterized.

Vladimir Ciobanu

The Structure and Chemical Composition of Ga2O3 Oxide Prepared by Annealing of Ga2Se3 Crystals

The chemical composition and structure of Ga2O3 obtained by thermal treatment (TT) in air of β-Ga2Se3 crystals were studied using the X-ray diffraction (XRD) method, Raman spectroscopy, EDX, and SEM. The surface of the Ga2Se3 crystal air annealed at 770 K is covered by β-Ga2O3 layer of microcrystallites and as well as by β-Ga2Se3 crystallites. The oxygen is non-homogeniously distributed on the surface of the 770 K annealed sample. The sample obtained by TT at 1150 K consists of nanolamella, nanotowers, and nanobars of β-Ga2O3, their size being estimated to 10–200 nm.

V. Sprincean, E. Vatavu, L. Dmitroglo, D. Untila, I. Caraman, M. Caraman

The Use of Metal Oxide Semiconductors for THz Spectroscopy of Biological Applications

Terahertz (THz) waves refer to the electromagnetic radiation in the frequency range from 0.1 to 10 THz, which corresponds to the wavelengths from 3 mm to 30 µm, respectively. This spectral region, called also as “T-gap”, is important for many practical applications, including THz imaging, chemical and biological sensing, high-speed telecommunication, security and medical applications. THz waves have low photon energies (~4.1 meV for 1 THz), which is about 1 million times weaker than the energy of X-ray photons. They do neither ignite any explosive materials at typical power levels nor cause any harmful ionization in biological tissues. The terahertz radiation is strongly attenuated by water and is very sensitive to water content. Unique THz absorption spectra caused by intermolecular vibrations in this spectral region have been found in different biological materials and tissues. Thus, Terahertz spectroscopy provides a powerful tool for characterization of a great many bio molecules and tissues. All these applications require relatively high power terahertz sources with milliwatt-level output power, which could operate at room temperature. Despite great progress, made in the last few years of design, fabrication and demonstration, THz devices based on GaAs/AlGaAs materials, there are some limits of bandgap engineering due to the relatively low (0.72 eV for GaAs/AlAs) conduction band offset, and most terahertz sources with one milliwatt-power like quantum cascade lasers (QCLs) require cryogenic cooling down to less than 200 K. To overcome the issue the new material systems such as metal oxide materials are considered as promising for room-temperature THz sources. The interest in terahertz imaging and spectroscopy of biologically related applications is increasing more and more within the last few years. This paper provides a review and current status of using metal oxide materials for THz spectroscopy, and recent advances in terahertz spectroscopy techniques in biological and medical applications.

H. L. Hartnagel, V. P. Sirkeli

ZnO-Based Quantum Structures for Terahertz Sources

In this paper we report on the numerical study of the terahertz devices based on metal oxide semiconductors and its application in biology and medicine. We also report on the recent progress of the theoretical and experimental studies of ZnO-based THz quantum cascade lasers (QCLs) and resonant tunneling diodes (RTDs). We show that ZnO-based semiconductor compounds are promising materials for fabrication terahertz sources operating up to room temperature due to their unique properties such as large bandgap and conduction band offset (CBO) energy, high LO-phonon energy, and high resistant to the high breakdown electric field. Moreover, it was established that the ZnO-based terahertz sources can cover the spectral region of 5–12 THz, which is very important for THz imaging and detection of explosive materials, and which could be not covered by conventional GaAs-based terahertz devices. In terms of the reported significant progress in growth of non-polar m-plane ZnO-based heterostructures and devices with low density defects, it is open a wide perspective towards design and fabrication of non-polar m-plane ZnO-based high power terahertz sources with capabilities of operation at room temperature.

V. P. Sirkeli, H. L. Hartnagel, O. Yilmazoglu, S. Preu

Surface Modification of PVDF Copolymer Nanofiber by Chitosan/Ag(NP)/Nanosilica Composite

PVDF copolymer nanofiber showed good chemical, mechanical and high hydrophobicity properties. PVDF copolymer nanofiber can be modified and functionalized by introducing hydrophilic and antibacterial materials such as chitosan composite. In this work, PVDF copolymer nanofiber with an average diameter 427.00 nm was modified by dip-coating process by using mixture of chitosan/Ag(NP)/nanosilica. Chitosan/Ag(NP)/nanosilica/PVDF copolymer nanofiber composite was successfully synthesized after analysis and confirmed by using ATR-FTIR spectroscopy, scanning electron microscopy (SEM), water contact angle and water spreading time analysis. SEM analysis showed the diameter of chitosan/Ag(NP)/nanosilica/PVDF copolymer nanofiber has an average diameter 443.50 nm. Post dip coating, it was found the specific vibration band peak IR spectrum which identify the presence of chitosan, SiO2, and the shifting band peak which was caused by interaction between chitosan and Ag0 in nanofiber composite. Chitosan/Ag(NP)/nanosilica/PVDF copolymer nanofiber composite with different content of nanosilica have lower water contact angle than pristine PVDF copolymer nanofiber. Water contact angle of PVDF copolymer nanofiber, chitosan/Ag(NP)/nanosilica (0.05%)/PVDF copolymer nanofiber and chitosan/Ag(NP)/nanosilica (0.20%)/PVDF copolymer nanofiber were 108°, 60° and 77°, respectively. Water spreading time analysis showed that modified PVDF copolymer has faster water spreading time than pristine PVDF copolymer nanofiber. It meant modification of PVDF copolymer nanofiber by chitosan/Ag(NP)/nanosilica gave hydrophilic and antibacterial properties to nanofiber.

M. Nasir, R. I. Sugatri, D. M. Agustini

Recent Progress in GaN-Based Devices for Terahertz Technology

This paper reviews the crystal growth, basic properties, and principle of operation of III-nitride based terahertz devices. We provide a brief history and current status of crystal growth of polar and non-polar GaN-based heterostructures and its properties. The role of spontaneous and piezoelectric polarization in polar III-nitride structures and its impact on performance of terahertz devices is discussed in detail. We show that GaN-based semiconductor compounds are promising materials for fabrication terahertz sources operating up to room temperature due to their unique properties such as large bandgap and conduction band offset (CBO) energy, high LO-phonon energy, and high resistant to the high breakdown electric field. Moreover, it was established that the GaN-based terahertz sources can cover the spectral region of 5–12 THz, which is very important for THz imaging and detection of explosive materials, and which could be not covered by conventional GaAs-based terahertz devices. In terms of the reported significant progress in growth of non-polar m-plane GaN-based heterostructures and devices with low density defects, it is open a wide perspective towards design and fabrication of non-polar m-plane GaN-based high power terahertz sources with capabilities of operation at room temperature.

V. P. Sirkeli, I. M. Tiginyanu, H. L. Hartnagel

Silanized Citric Acid Capped Magnetic Nanoparticles and Influence on Chlorophylls

Two step synthesis of cobalt ferrite nanoparticles capped with citric acid and coated with silica was carried out. Citric acid coated magnetic grains were synthesized by chemical co-precipitation starting from iron and cobalt salt solutions in stoichiometric ratio. Adapted sol-gel method was applied to yield the silica/citrate/cobalt ferrite nanocomposites. Microstructural and magnetic properties were evidenced by TEM, XRD and VSM. Nanotoxicity tests were done on maize plants during their early ontogenetic stages. Quantum mechanical characterization was performed with specialized software to evidence chlorophylls molecular properties for discussing their diminished contents in the green tissues of young seedlings supplied with magnetic nanocomposites.

L. Popescu, L. Sacarescu, M. Grigoras, C. Morosanu, D. Creanga, D. Dorohoi, C. Stan

Enhancement in Conductivity and Photoresponse of Ga Doped ZnO Nanofibers

Nanofibers ZnO and ZnO:Ga with a diameter of 100–250 nm were obtained by electrospinning. Introduction of Ga impurity at a concentration of 1 at. % leads to a significant increase in the conductivity of ZnO nanofibers. It is found that the temperature dependences of the conductivity of ZnO and ZnO:Ga films consist of two activation regions with different activation energies. Under the influence of UV radiation on the samples there is a long-term increase and decrease in conductivity associated with the processes of adsorption and desorption of oxygen molecules. It is shown that the Ga-doped ZnO sample has greater photoconductivity and photoresponse to UV radiation compared to pure ZnO.

M. N. Martyshov, A. S. Ilin, V. B. Platonov, P. A. Forsh, P. K. Kashkarov

Luminescence of β-Ga2O3 Nanoforms Obtained by Oxidation of GaSe Doped with Eu

The GaSe single crystals were doped with Eu in the process of their synthesis and growth. The oxide of β-Ga2O3 doped with Eu in the form of massive nanowires was obtained by thermal treatment (TT) in the atmosphere of GaSe single crystals doped with 1.0 and 3.0 at.% of Eu. The crystalline structure, surface morphology and photoluminescence spectra of GaSe:Eu and β-Ga2O3:Eu single crystals were studied. The Photoluminescence (FL) spectrum of GaSe doped with 1.0 at.% of Eu at room temperature is formed as a result of transitions of 5D0 →7F1 to Eu3+ ion and as a result of radiation annihilation of n = 1 excitons in GaSe. The FL spectra of Ga2O3:Eu was interpreted on the basis of the energy level diagram of electrons in Eu3+ ion.

V. Sprincean, D. Untila, A. Chirita, I. Evtodiev, I. Caraman

Sensorial and Local Reflectivity Properties of the Columnar ZnO:Eu Films

In this work, we report on sensorial properties dependent on the operating temperature for Eu-doped ZnO columnar samples. The films demonstrated sensorial properties to volatile compounds, namely for 2-propanol . The results have been explained by increased basic properties of ZnO after doping with ions of Eu, that lead to catalyzing of dehydrogenation processes of molecules, and higher response. Local reflectivity maps of the sensor samples with a very high spatial resolution were recorded by using a specially modified measurement set-up, which had been originally designed for the electrical characterization of photovoltaic solar cells. The variation of the local reflectivity of the active sensor area is caused by different film properties that are most probably the result of the deposition process and/or handling. In the future, a systematic analysis and correlation of the performance data of various sensor samples with such reflectivity maps may lead to a better understanding and improvement of the film deposition process and thus to finally better sensors.

C. Lupan, A. Schütt, A. Bîrnaz, M. Hoppe, R. Adelung

Effects of Heat Treatment on Palladium-Doped Zinc Oxide on Sensory Selectivity

In this paper I investigated the sensor response based on palladium-doped zinc oxide. How did the hydrogen and ethanol response change to a simple sensor that was not treated quickly and a heat treatment at 650 °C.

N. Magariu

Mechanical and Wetting Properties of Three-Dimensional Flexible Tetrapodal ZnO Networks ALD-Coated with Al2O3

Nano- and microscale tetrapodal shaped ZnO particles (T-ZnO) are considered to be truly multi-functional and have a tremendous potential for a large variety of applications ranging from gas/vapor sensors to biomedical implants. In this approach highly porous interconnected networks were formed from T-ZnO particles produced by the versatile flame transport synthesis (FTS) at Kiel University and coated by Al2O3 with different film thicknesses by atomic layer deposition (ALD) technique. Presence of Al2O3 inside the network was confirmed by the energy-dispersive X-ray spectroscopy (EDX). Compression tests showed that with increasing Al2O3 coating thickness mechanical properties were significantly improved, e.g. the Young’s modulus of networks with a T-ZnO density of 0.5 g/cm3 was raised from 1.0 ± 0.3 MPa (pure T-ZnO) to 1.80 ± 0.2 MPa when coated with 60 nm Al2O3, whereby the elastic limit (yield strength) was increased by a factor of two as well. Contact angle (CA) measurements revealed that switching of wetting properties from super hydrophilic (water droplet is rapidly sucked into the network) to super hydrophobic (water droplet lies on the surface with CA = 142° ± 2°) is possible depending on the hydration state of Al2O3. The successful combination of T-ZnO and Al2O3 can further broaden the application range of T-ZnO particles, e.g. for humidity detection as well as in the field of bio-electronic devices.

A. Gapeeva, M. T. Bodduluri, S. Kaps, F. Rasch, B. Wagner, R. Adelung, O. Lupan

Polarization Holographic Recording on Photosensitive Polymers

In this paper we report on direct holographic recording of surface relief gratings in carbazole-based polymers. Evolution of the transmittance spectrum and diffraction efficiency upon irradiation with 532 nm laser light demonstrated the photo-induced surface patterning of gratings.

E. Achimova, V. Abaskin, A. Meshalkin, A. Prisacar, L. Loghina, M. Vlcek, A. Yakovleva

QDs Doped Azopolymer for Direct Holographic Recording

This paper describes a direct holographic recording of surface relief gratings in QD doped carbazole-based polymers. The evolution of the transmittance spectrum and diffraction efficiency upon irradiation with 473 nm polarized laser light demonstrated the photo-induced surface patterning of gratings.

C. Loşmanskii, E. Achimova, V. Abaskin, A. Meshalkin, A. Prisacar, L. Loghina, M. Vlcek, A. Yakovleva

Radiative Recombination of Bound Excitons in MoSe2:I2 Layered Crystals

The steady-state and time-resolved photoluminescence (PL) of excitons bound on intercalated iodine molecules was studied for the first time in MoSe2:I2 layered single crystals. Along with narrow exciton spectral lines located near the energy of the MoSe2 indirect bandgap in the region of 0.98–1.06 eV, an IR broadband radiation centered at 0.78 eV and caused by the recombination of photoexcited carriers through the intrinsic lattice defects were found. To describe the temperature dependences of the intensity of steady-state PL, as well as its temporal characteristics, a kinetic model was proposed that takes into account the radiative and non-radiative recombination channels present in this quasi-two-dimensional semiconductor.

N. Siminel, V. Nedelea, K. Sushkevich, A. Siminel, A. Micu, L. Kulyuk

Acetone Sensing Properties of Nanostructured Copper Oxide Films on Glass Substrate

Copper oxide nanostructured films were synthesized via a chemical synthesis (SCS) method and annealed in low vacuum. The morphological properties were investigated using scanning electron microscopy (SEM). The elaborated sensor structures based on CuO/Cu2O films were tested to 100 ppm of acetone vapor. It was observed that by applying different temperatures for rapid thermal annealing the surface morphology of the films can be modified, as well as the composition of the films, which leads to the changes in gas response value for the tested gases. The possibility of controlling the sensitivity of the sensors by changing the RTA treatment temperature and the operating temperature was demonstrated.

V. Cretu, N. Ababii, V. Postica, N. Magariu, M. Hoppe, V. Verjbitki, V. Sontea, R. Adelung, O. Lupan

Influence of the Growth Temperature on the Properties of the Transparent and Conductive NiO Thin Films Obtained by RF Magnetron Sputtering

Transparent and conductive nickel oxide (NiO) thin films were deposited on the glass supports by magnetron pulverization (RF). The NiO thin films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), SEM equipped with X-ray detector-analyzer (EDX), UV-VIS spectroscopy and Hall measurements. XRD revealed that the NiO thin films obtained at different substrate temperatures are textured and possess a cubic crystalline structure. SEM analysis indicates the formation of the crystallites with a granular structure. The EDX spectra of the NiO thin films highlighted the presence of Ni and O as elementary components. With the increase of the substrate temperature from 50 to 450 °C Hall measurements show a decrease of the resistivity of the NiO thin layers due to the increase of the concentration and mobility of the free carriers.

L. Ghimpu, V. Suman, D. Rusnac

Plasmonics and Metamaterials

Frontmatter

Active Spectral Absorption Control in a Tunable Liquid Crystal/Metamaterial Structure by Polarization Plane Rotation

We present theoretical studies conducted on the newly-introduced controllable metamaterial—liquid crystal system. Our model consists of a standard metamaterial single cell split ring resonator array with dimensions tailored to match a desired frequency in the infrared frequency regime, with an added liquid crystal layer, in order to control the refractive index surrounding the resonator array. We show that this type of system can show controllable spectral absorption in the desired range, making them suitable for a range of optical applications.

A. Bărar, O. Dănilă, D. Mănăilă-Maximean, V. A. Loiko

Spectral Investigation of Surface Plasmon Resonance Bands of Silver Nanoparticles Capped with Gallic Acid

The study of silver nanoparticles fabricated more and more for textile industry, cosmetics, pharmaceutics and other utilizations has led to the diversification of synthesis protocols. First we present single pot reaction of silver nitrate with gallic acid, rather newly used as reducer, with focus on the influence of reaction parameters on the Surface Resonance Plasmon bands of resulted silver nanoparticles. Four experimental variants of chemical reduction were conducted at room and at 60 °C, at 7.5 pH and at 10.5 pH. Secondly, two phase photochemical reduction with gallic acid using UV exposure was carried out. The Surface Plasmon Resonance spectral band of silver nanoparticle suspensions was rather broad indicating dimensional polydispersion, while symmetrical shape and maximum position suggested dominant spherical nanosized particles. The study of aged samples yielded by one pot reduction revealed higher stability for alkali samples. In the case of photochemical synthesis, submicron particles in not stable suspension were revealed. To support spectrophotometric experimental data, Transmission Electron Microscopy imaging was done, revealing tens of nm particles in the case of chemical reduction but considerably larger particles, over 100 nm in the case of photochemical synthesis. The results discussion was based on the influence of reaction conditions (temperature, pH, UV exposure) on the silver particle spectral properties and also on the capping molecular shell.

L. Popescu, G. Ababei, D. Babusca, D. Creanga, C. A. Benchea, N. Lupu, L. Oprica

Bio-micro/nano Technologies and Devices

Frontmatter

Cathodoluminescent UV Sources for Biomedical Applications

Ultraviolet radiation is widely used in biomedical practice. In some areas, its use is limited by the lack of sufficiently cheap sources of the desired spectrum and power. The prototypes of mercury-free cathodoluminescent UV-radiation sources are manufactured. They use field emission cathodes on the basis of carbon fiber. These sources exhibit various UV spectra depending on the phosphors used. New types of UV-emitting cathode-ray-tube phosphors are suggested.

D. I. Ozol, E. P. Sheshin, M. I. Danilkin, N. Yu. Vereschagina

European Terahertz Technology for Environmental Monitoring and Bio-friendly Imaging

Main properties of Terahertz Waves are analyzed in view of potential applications for radio astronomy and bio-friendly imaging applications. A short overview of European State-Of-The-Art Technology is provided.

O. Cojocari, M. Hoefle, D. Mopro-Melgar, I. Oprea, M. Rickes

Synthesis and Characterization of Self-assembled Submicron Particles Based on Biotinylated N-palmitoyl Chitosan

Self-assembled particles based on amphiphilic chitosan derivatives represent a promising research area, as remarkable properties of these polymeric structures can significantly improve their biological behaviour of the drug delivery systems. In the same time, biotin has been proposed as an active targeting molecule in anti-tumoral formulations. In this paper, self-assembled submicron particles based on biotinilated N-palmitoyl chitosan and loaded with a chemotherapeutic agent (Paclitaxel) have been prepared by dialysis method combined with ultrasonication. The composition of the particles has been confirmed by FT-IR Spectroscopy. Paclitaxel loaded particles exhibited narrow size distribution, negative charge, a pH-dependent release profile of drug and redispersion ability in simulated body fluids, features which can be useful in drug delivery applications.

V. Balan, C. I. Moise, L. Verestiuc

Biomaterials for Medical Applications

Frontmatter

A Novel Nanocomposite (SR/HA/-nZnO) Material for Medical Application

A novel biocomposite material SR/HA/ZnO for maxillofacial prosthetics and jawbone. In this work, hydroxyapatite synthesized by sol-gel technique. Ca(NO3)2·4H2O and (NH4)2HPO4 used as precursors, and nano ZnO was prepared and modify the surface using Oleic acid to get uniform distribution Within the matrix and reduce nanoparticles agglomeration ZnO. Silicone rubber composites were prepared as a second part by using HA as to increase the biocompatibility, mechanical properties of SR, and to get antibacterial nanocomposites ZnO modified were used. The mechanical properties as a property of tensile strength, elastic modulus, elongation, hardness, compressibility, and antibacterial were examined after the addition of HA and ZnO to silicon rubber. The results show the ability to prepare n-ZnO and HA used to enhance the mechanical properties also acts as antimicrobial media for the biocomposite that can be used for prosthetics and jawbone.

H. Sh. Majdi, A. N. Saud, M. H. Al-Mamoori

Influence of MW Irradiation on the Hydroxyapatite/Chitosan Composite Structure and Drug Release Kinetics

Biocomposite material based on hydroxyapatite (HA) and chitosan (CS) in form of beads was synthesized using microwave irradiation (MW) of different power and investigated by methods of XRD and HPLC. MW reduces the time of HA formation to 20 min without affecting its structure. Liquid absorption and liquid retention for the synthesized at maximum MW power HA-CS-MW800 sample is 27%, while for the control HA-CS 5%. HPLC showed significant differences in the release kinetics of the hydrophilic Chlorhexidine (CHX) and hydrophobic benzocaine (BZ) and proved the composite ability to prolonged drug release to 336 h for CHX and 384 h for BZ. The HA-CS-MW800 demonstrates the highest release rate for CHX and the lowest one for BZ. From HA-CS-MW800 sample in the first 2 h is released the smallest amount of BZ (about 32%), compared to 45% for others. The effect of MW contributes to the specific location of binding sites in composite and access of drug molecules to these sites.

L. B. Sukhodub, M. O. Kumeda, L. F. Sukhodub

Improvement of the Antibacterial Activity of Benzylpenicillin in Combination with Green Silver Nanoparticles Against Staphylococcus aureus

The antibiotic resistance crisis is one of the most pressing public health issues worldwide. Nanoparticles (NPs) can offer a promising solution, since they have antibacterial properties, and can act as carriers for antibiotics and natural antimicrobial compounds. The purpose of this work was to study the antibacterial activity of silver nanoparticles, which are obtained by “green synthesis” from Ocimum araratum extract, against Staphylococcus aureus bacteria, as well as to study their combined action with antibiotic benzylpenicillin. The results show that the antibacterial effect of silver nanoparticles is higher than that of nanoparticles stabilized by the extract on the growth of S. aureus. It has been shown that benzylpenicillin can interact with the allosteric site of penicillin-binding protein 2a. It has also been shown that “green” AgNPs, which include phytocompounds of the extract of O. araratum can enhance the antibacterial effect of benzylpenicillin synergistically.

S. Ohanyan, H. Grabski, L. Rshtuni, S. Tiratsuyan, A. Hovhannisyan

Functionalization of Flavonoids (Quercetin) to Chitosan Matrix and Determination of Antioxidant Activity of Obtained Bio-composites

In recent years, particular attention has been paid to antioxidant systems functionalized with natural organic polymers such as starch, dextran and especially chitosan. Chitosan is a polysaccharide with very good functional properties, which is obtained from natural sources and has a range of applications. The most significant improvement of chitosan macro-molecules is focused on the functionalization of natural biologically active compounds from the flavonoid group such as quercetin and others in its polymeric structure. Within the given paper, new compounds of chitosan were synthesized with quercetin natural antioxidant. The antioxidant activity of modified chitosan was determined and changes in the chemical structure of chitosan and quercetin were established.

M. Gonta, E. Sirbu, S. Robu, A. Gonta, L. Mocanu

Molecular Docking of Compounds Modulating Amyloid Peptide Aggregation Schemes

Alzheimer’s disease is characterized by the formation of plaques in the brain, which are commonly composed of amyloid peptides as a result of aspartyl protease β-secretase expression. This work is dedicated to in silico studies of the interaction of artemisinin, dihydroartemisinin, dihydroartemisinin dimer with amyloid 12Aβ9–40 peptide and β-secretase. The comparison was made with curcumin, which is in phase II of clinical trials. It has been shown that all ligands, similarly to curcumin, bind to the specific amino acids of the peptide that are responsible for the formation and the growth of the fibril with high affinity. Moreover, dihydroartemisinin and dihydroartemisinin dimer bind to amino acids that are responsible for the stabilization of formed fibril. All studied ligands interact with the critical amino acids of the catalytic center of β- secretase, while dihydroartemisinin dimer can also bind to Arg235, which is characteristic of peptide inhibitors of β-secretase. Dihydroartemisinin dimer has a higher binding affinity compared to other ligands. Thus, the selected compounds can be considered as possible candidates for the treatment of Alzheimer’s disease.

S. Ginosyan, Y. Hambardzumyan, T. Mkrtchyan, H. Grabski, S. Tiratsuyan

Use of the Auto Osteomatrix Forte Graft in Total Tympanomastoid Dissection

The study aim is to evaluate the efficacy of meatotympanoplasty with the use of the auto osteomatrix forte graft (AOMF) associated with temporal fascia and mastoid obliteration with pediculated musculoperiosteal flap in patients after total tympanomastoid dissection (ETMT) in comparison to patients after revision surgery of the evidation cavity. Materials and methods: The prospective cohort study which included 2 batches of patients, 58 patients with ETMT and reconstruction by means of the elaborated method, and 59 patients with revision surgery of the evidation cavity and reconstruction by means of the elaborated method. The patient batches were similar according to age, gender and living environment. Results: 12 months postoperatively, in all patients of both study groups was determined: significant decrease of complaints, ameliorated anatomical outcomes (small, clean and dry evidation cavity), eradication of the evidation cavity pathology, improvement of the auditory functional results (statistically significant increase in the perception of voice on whispering and speech, airway and bone conduction), improvement of the vestibular function and life quality. Conclusions: Meatotympanoplasty with the use of the auto osteomatrix forte autograft when associated with the temporal fascia and the mastoid dislocation with pediculated musculoperiosteal flap is a feasible and safe technique for pathology eradication involving the evidation cavity. The use of the autologous bone for reconstruction is effective for the stability of the external auditory canal and for the tympanic membrane. It preserves and/or restores hearing, and has a lot of advantages: is immediately available in primary and revision surgeries, is economical, does not cause inflammation processes in the body, contributes to the growth of the new bone, reduces the risk of infection, resorption and subsequent degradation and improves life quality.

I. Ababii, S. Vetricean, V. Smetanca, L. Danilov

Composite Metamaterials for Biological Decontamination of Fluids

The dependence of the contact surface of contaminated fluids with metamaterial, formed from various dimension quartz bubbles is proposed. As a simple mathematical model is proposed to packing the space between the relative big spheres with the smaller one with dimensions d1/10, d1/102,…, d1/10n. Here d1 is the diameter of packing the biggest spheres in the system. It is established that this contact surface increase in such metamaterial and becomes proportional to the surface of the smallest spheres proposed in the model. In order to confirm these results experimentally, we propose a series of experiments with yeast fungus dissolved in the water. The systems of metamaterial like fiber optics, a system of quartz bubbles and composite granulated quartz material were proposed in order to demonstrate this effect. The qualitative correspondence between the experimental results and a theoretical model is obtained.

N. A. Enaki, M. Turcan, S. Bazgan, E. Starodub, T. Paslari, A. Nistreanu, C. Ristoscu, I. N. Mihailescu

Study of a Customized Implant in Cranio-Maxillofacial Surgery

Latest developments in engineering are increasingly applicable in medicine. The use of Additive Manufacturing (AM) methods in the customized surgery can improve the patients’ life quality. The customized implants are created in the pre-surgical stage, on the basis of the medical data acquired by computer-assisted-tomography or nuclear magnetic resonance using three-dimensional virtual models and CAD/CAM techniques. The paper presents the required steps for manufacturing a customized cranial implant. During this study, a cranial defect was reconstructed using a personalized cranioplasty plate produced by AM methods. The surgery was successful and the patient feels well, has an improved physical aspect after implantation.

C. Miron-Borzan, H. Chezan, C. Buciuman, E. Sabau

Hydrogels Based on Collagen and Dextran for Bioartificial Tissues

Hydrogels are crosslinked polymeric networks with a large number of hydrophilic domains. They can expand in numerous solvents and aqueous environments without dissolving owing to the chemical or physical bonds formed between polymer chains. During the past decades, hydrogels have been designed using synthetic or natural polymers like proteins or polysaccharides for biomedical applications such as tissue engineering. Due to its biocompatibility and its structure, most commonly used in tissue engineering is collagen, the most abundant structural protein of the extracellular matrix, which is predominantly found in fibrous connective tissues. In the present study to obtain hydrogels alongside collagen was used also dextran, a polysaccharide derived from glucose condensation. The crosslinking was made under the influence of riboflavin, which is a water-soluble vitamin that plays an important role in the production of energy in the body. In addition, the hydrogels have been exposed to physical treatments like UV radiation and lyophilization. The hydrogels were characterized using FT-IR spectroscopy and to highlight the hydrogels porous was used microscopy in phase contrast and fluorescence microscopy. The citocompatibility tests (MTT) indicated normal values for the cells viability in the presence of hydrogels. For detection of living cells the hydrogels a treatment with calcein AM solution was used and for detection of living cell nuclei was used the DAPI solutions.

Maria Butnaru, A. M. Lucaci, B. P. Cosman, L. Verestiuc

Biomimetics and Sensors

Frontmatter

Microelectronic Pyroelectric Measuring Transducers

The basic pyroelectric structures and circuits of measuring transducers on their basis are given. The prospect of the use of thin pyroelectric films for the development and design of microelectronic pyroelectric measuring transducers based on transistor structures with negative differential resistance is shown.

Andriy O. Semenov, S. V. Baraban, O. V. Osadchuk, O. O. Semenova, K. O. Koval, A. Yu. Savytskyi

Ionizing Radiation Dose Sensor Based on n-channel MOSFET

We investigated the radiation sensitivity of dose-metrical sensors based on n-channel MOSFETs taking into account the effects of temperature and electrical modes. There were measured the output voltages V being equal to the gate voltage VG of MOSFET-based dosimeter as function of the radiation doses at const values of the drain current ID and the drain—source voltage VD (conversion functions), as well as the (ID − VG) characteristics before, during and after irradiations at different temperatures. It was shown how the conversion functions and the radiation sensitivities are depending on the temperature and electrical modes. It is found that the conversion functions V(D) have two characteristic regions for low and high doses (with negative and with positive radiation sensitivities). To interpret experimental data there were proposed the models of conversion function and its components taking into account the separate contributions of charges in the dielectric and in SiO2–Si interface.

B. I. Podlepetsky, V. S. Pershenkov, V. V. Belyakov, A. S. Bakerenkov, V. Felitsyn, Alexander S. Rodin

Conductance and Photoconductance of Indium Oxide-Zinc Oxide Composites in the Hydrogen-Containing Atmosphere

Photovoltaic properties of composites based on nanocrystalline indium and zinc oxides, promising as sensitive elements of gas sensors, were investigated. It is shown that under visible light the conductivity of composites changes with the change of hydrogen concentration in the environment even at room temperature, which allows the use of composites to detect hydrogen without heating. The curves of the kinetics of photoconductivity of the composites are studied and possible mechanisms of photoconductivity are analyzed. The mechanism of the sensor response of composites under illumination is proposed. The mechanism considers the illumination turns the composite into nonequilibrium state and the photoconductivity change in the H2 atmosphere is linked with alteration of nonequilibrium charge carriers recombination rate.

A. S. Ilin, P. A. Forsh, M. I. Ikim, A. V. Koroleva, M. N. Martyshov, L. I. Trakhtenberg, P. K. Kashkarov

Biomedical Instrumentation

Frontmatter

Visual Control of Human Locomotion

An objective method for instrumental assessment of the state of the human locomotion system in real time has been proposed. A universal method of studying human motor functions based on the principles of technical vision has been developed. Using the visualization of the projection of the three-dimensional location of the sensors on the profile, frontal and horizontal planes allows to assess the current state of the spine and can be widely used in clinical practice.

H. N. Rozorinov, N. I. Chichikalo, E. H. Arkhiiereieva, E. Yu. Larina

Method for Performance Evaluation of Electrostimulation of the Lower Esophageal Sphincter

Recognized world experience could confirm, that gastroesophageal reflux disease (GERD) is one of the most common gastroenterological diseases. In many cases conservative treatment is not efficient, that could lead to severe complications. Existing options like antireflux laparoscopic surgery in recent years were supplemented with direct tone modulation of lower esophageal sphincter (LES) with implantable electrical stimulator. Having experience in development of wireless powered LES electrostimulators (WPLES), authors elaborated simple and inexpensive method of assessing the effectiveness of LES stimulating devices during tests on laboratory animals.

V. Sontea, S. Ungureanu, N. Sipitco, D. Fosa, V. Vidiborschii

Profile Forming of Infrared Cabin User’s Biomedical Indicators

The construction and methodology of a infrared cabin developed by the authors for activation of human body functional reserves are described in the article. A device is equipped with a system of human physiological parameter monitoring. The results of thermal load level produced by the infrared cabin on the human cardiovascular system are presented.

M. M. Mezhennaya, A. V. Vorobey, V. Y. Drapeza, A. N. Osipov, S. K. Dick, M. X.-M. Thostov

The Algorithms Modernization of Temperature and Gas Control Systems of Ion Mobility Spectrometer

New algorithms were developed to control the drift region heaters and the gas pumps of ion mobility spectrometer. The efficiency of substances detection was increased. Control algorithm block heaters can improve the accuracy of temperature stabilization in terms of the significant events of the time constants of thermal circuits and high heat capacity elements of the drift region. The improved control algorithm of a block of gas pumps minimizes the duration of the transition process when changing the predetermined level of the engine speed over a wide range. The study and optimization of control algorithms for heaters of the drift region and the gas pump ion mobility spectrometry.

Y. R. Shaltaeva, A. V. Golovin, V. K. Vasilyev, E. A Gromov, M. A. Matusko, E. K. Malkin, I. A. Ivanov, V. V. Belyakov, V. S. Pershenkov

An Optimal Path Planning Proposal for Motion Robots with Specific Constraints Applicable in Biomedical Engineering

Optimal path planning for motion robots is an interesting research subject with many applications in various domains including biomedical applications when a mobile robot can distribute medication for patients. A fuzzy environment with object approximated by ellipses is a common situation in terrain applications when a mobile robot must find an optimal route. In some situations, e.g. biomedical applications, some additional constraint related to medical instrumentation impose to find some pathway where a mobile robot must be at an equal distance between the objects in order to have a good balance between possible electrical influences or specific requirements. The results show a feasible solution that can be implemented for predefined routes which must go among a marked set of objects, left and right parts of the mobile robot.

C. Corciovă, M. Turnea, A. Gheorghiţă, D. Arotăriţei

Intelligent System for Monitoring Vital Signs at Patient’s Home

The primary concern in present healthcare systems is increasingly shifting towards chronic diseases. This presents itself with the difficulty to monitor and follow-up a demanding number of patients. Technology development allows to significantly improving the quality of life. The aim of this project is to monitor a number of vital functions while making it accessible for the patients and the care takers. The vital functions of interest were: heart’s electrical activity, heart rate, oxygen saturation levels in peripheral blood, arterial blood pressure, temperature and galvanic skin response. In addition, there is the possibility of geo-tracking. The system uses a Healthy Pi board for data acquisition using the Linux operating system. The ECG module is based on an operational amplifier with multiple filtering levels so as to acquire a series of signals corresponding to a physiological graph in one lead which are sent to an Atmega microcontroller. They are forwarded towards the Raspberry Pi platform which compiles and shows it on the attached display. Signal calibration was done using a simulator for ECG testing for physiological and pathological heart conditions (ventricular fibrillation, heart stroke). The pulse-oximetry module determines the oxygen saturation levels in blood, but also helps monitor/compare the peripheral values (upper limbs) of pulse against heart rate according to the ECG. The advantages of this system consist of: efficient, quick data acquisition and storage, remote real time monitoring, friendly user interface, possibility of geo-tracking, accessibility for the patients and care takers.

R. Fuior, D. Andriţoi, C. Luca, C. Corciovă

Bio-behavioral Aspects of Patients with Ocular Problems with Implications for Optometric Comfort

The cultural, socio-professional, economic or ideological constraints define and delimit the framework in which human behavior evolves in different situations and which allows the building of a coherent and clear communication system as far as possible. It is therefore important to understand that human subjects are not an image, but that each of them has a reflection of the inner and outer environment to which they relate. In the first part of the paper are presented some general aspects regarding the importance of the optometrist specialist in all stages of interaction with human subjects (information, examination, correction, guidance). The second part of the paper identifies and analyzes a number of important aspects of human bio-behavior in order to establish the coordinates for visual comfort, increase self-esteem or visual aid, where appropriate, in the case of this new profession—optometry developed in Romania. In the final part of the paper are presented the results of this analysis and the conclusions from the processing of the information of a sample of 70 subjects with different parameters for obtaining a more general image related to bio-behavior of patients with ocular problems with implications for the optometric comfort and to find the best solutions for patients.

M. I. Baritz, A. M. Lazar, M. G. Apostoaie

Biomedical Signal Processing

Frontmatter

Testing the Heart Rate Coherence Function for Detecting and Identifying Atrial Fibrillation

Today, one of the main directions in the diagnosis of the heart is the study of long-term registrations and analysis of statistical data of cardintervals (RR-intervals) and amplitudes of various sections of the ECG. However, the processing of a complete cardiogram in real time and its transfer for analysis using wireless communication lines is quite problematic due to the large data volume and high requirements for the processing power of the processing system. The article proposed the method of using coherence functions for a sequence of RR intervals, which make it possible with high accuracy to determine the onset of atrial fibrillation. This type of heart disease is one of the potentially lethal and its occurs mostly hidden. However, atrial fibrillation increases the risk of stroke by 6–8 times. This method does not require the exchange of large amounts of data and can be used in wearable cardiomonitoring devices.

Y. Sokol, P. Shapov, M. Shyshkin, R. Tomashevskyi

Dense Array Electroencephalography-Based Electric Source Imaging of Interictal Epileptiform Discharges

Electric source imaging (ESI) based on dense array electroencephalography (EEG) is a non-invasive technique for source localization of epileptic activity. However, the diagnostic accuracy of this tool is still debatable. In this study we aimed to investigate the source of epileptiform discharges in a group of epilepsy patients. For this, 20 patients (24.4 ± 8.0 years, 10 males) with drug-resistant focal epilepsy were included. All patients underwent 256-channel EEG recordings and were imaged on a 3T MRI scanner according to a predefined protocol. For spatio-temporal source reconstruction, LORETA (low resolution brain electromagnetic tomography) solution was applied to interictal averaged spikes. Electric sources of epileptiform discharges were detected in all 20 patients. In 18 (90%) patients source localization was concordant with patients’ seizure semiology. The most frequent source was identified in the temporal lobe. Dense array EEG is an accurate modality for localization of epileptogenic brain areas in the pre-surgical evaluation of drug-resistant epilepsy patients.

S. A. Groppa, D. Ciolac, A. Vataman, V. Chiosa

Cardiorespiratory Coupling: A Review of the Analysis Methods

Interaction between cardiovascular and respiratory systems were studied intensively over the last few decades, in order to understand the principles of cardiorespiratory interactions in healthy and non-healthy subjects. Different physiological conditions such as REM sleep, anesthesia, stress, post-stress were used in order to determine and analyze the hidden parameters, that regulate the synchronization between these two integrated physiological systems and their behavior. This paper aims to review the most common methods of analysis of the cardiorespiratory coupling and their capacity to provide additional information for diagnosis and prognosis in medicine.

V. Tonu, V. Vovc, N. Enache

Recording of the Breathing Pattern in the Test with Controlled Hyperventilation in Subjects with a Borderline Type Personality Disorder

The study of the variations of breathing pattern components under the influence of physiological or pathological factors allows to deepen the knowledge in the field of physiology of systemic interaction in the whole body as well as in the pathophysiology of functional, psychosomatic diseases. Taking into account the prevalence of 6% of borderline type personality disorder in primary care and up to 20% in specialized psychiatric centers and the considerable impairment caused to patients, the study of the breathing pattern could offer doctors, especially those at the primary level, an alternative to treatment pharmacologically by correcting the psychophysiological mechanisms of systemic dysfunction. The study was conducted on a group of 95 people between March 2017 and February 2019 at the Department of Human Physiology and Biophysics, USMF “N. Testemitanu”. The psychometric assessment preceding the recording of respiratory parameters was performed with the Personality Inventory Test PID-5. The respiratory pattern parameters were recorded using respiratory plethysmography and capnography. The experimental protocol included the recording of respiratory pattern parameters in 3 functional samples (resting breath, hyperventilation test, post-hyperventilation test). In the subjects with borderline type personality disorder group following characteristics of the breathing pattern at rest have been observed—ower tidal volume, higher respiratory frequency and lower end-tidal CO2.

S. Lozovanu, I. Moldovanu, V. Vovc, T. Besleaga, A. Ganenco

Encephalographic Signal LabView Processing

The research presented in the present paper concern the treatment of signals obtained from monitoring the encephalic function through electroencephalogram. The signal processing is based on the creation of a routine in named Labview software, which allow analyzing both electrocardiographic and electroencephalographic (EEG) signals. Automatic interpretation of an EEG implies analyzing a large diversity of normal and abnormal wave forms on a great number of channels. EEG monitoring aims the detection of significant changes either for slow and fast waves (spikes). A routine was created in LabVIEW software for processing the EEG signal and to indicate anesthesia degree (cerebral state index). After caption and filtering, the signal is distributed through four channels corresponding the electroencephalographic frequencies. Further, the signal was transformed as to be possible its graphic representation and, the Cerebral state index was estimated by implementing its specific formula and expressed by a numerical value. This application has the advantage to save data in different formats as to be visualized and interpreted by other software giving the graphic representations (Excel, Origin etc.). It also allows to be used for a great number of subjects, depending on PC memory, and it is easy and friendly to use for persons that have no specific IT education. The last but not the least, it is very low cost: LabVIEW license and low cost for acquisition board and little other accessories.

I. C. Roșca, C. Drugă, I. Șerban, R. D. Necula

Multifocal Repetitive Transcranial Magnetic Stimulation—A Novel Paradigm in Migraine Treatment

Transcranial Magnetic Stimulation (TMS) is a non-invasive brain stimulation method used for analyzing structural and functional interactions in brain, assess cortical reactivity, and map functionally relevant brain regions inducing a controlled current pulse in a defined region of the cortex. From a clinical point of view, TMS has shown promising results in the therapeutic approach in a large number of psychiatric and neurological conditions such as anxiety, depression, OCD, headache disorders—migraine being one of the most encountered, etc. In patients with migraine, the pharmacologic therapy can be divided in abortive and preventive treatment of the attack. Usually the treatment is started with simple analgesics and non-steroidal inflammatory; nevertheless, many individuals continue to have attacks refractory to various prophylactic and/or abortive therapies, while others are at high risk of developing medication overuse headache. Among non-pharmacologic therapies TMS has been broadly studied as a preventive migraine treatment with good outcome results.

P. Leahu, S. A. Groppa, M. Bange, S. Scheiter, D. Ciolac, V. C. Chirumamilla, M. Muthuraman, S. Groppa

Biomedical Imaging and Image Processing

Frontmatter

Remodeling of Cortical Structural Networks in Multiple Sclerosis

Multiple sclerosis (MS) is one of the most frequent immune-mediated disorders of the central nervous system. Pathological events occurring within the white matter and gray matter compartments can be reliably tracked in vivo by magnetic resonance imaging (MRI) but conventional imaging parameters do not reflect the remodeling processes of the brain. Here, we sought to investigate the reorganization of cortical structural networks in a group of patients with MS. For this, 40 patients (mean age ± standard deviation 31.2 ± 7.0 years, 14 males) with relapsing-remitting MS and 40 healthy subjects (27.1 ± 5.0 years, 14 males) were included in the study. From T1-weighted MR image-derived cortical thickness values, connectivity matrices were generated and network measures of integration and segregation compared between the groups. MS patients presented higher modularity, clustering coefficient and local efficiency but lower global efficiency when compared to healthy subjects. These results indicate that remodeling of cortical structural networks in patients with MS occurs towards the strengthening of intramodular connectivity and local processing. Presumably, this reorganized network architecture topology is an adaptation response required to maintain brain networks’ functionality in conditions of ongoing tissue damage.

D. Ciolac

Polarization Tomography of Synovial Fluids Polycrystalline Layers

The experimental and diagnostic capabilities of the polarization tomography method of linear birefringence distributions of polycrystalline films of the synovial fluid of a human joint in the differentiation of its pathological states are considered. Present the structural-logical scheme and analytical description of the differential diagnosis of aseptic and septic loosening of the artificial hip joint endoprosthesis using the methods of differential Mueller-matrix mapping.

V. V. Protsiuk, V. L. Vasiyk, Y. M. Vasylchishyn, O. G. Ushenko, M. V. Shaplavskiy, O. B. Bodnar, A. V. Dubolazov, Yu. O. Ushenko, Yu. Ya. Tomka

Differential Muller-Matrix Microscopy of Protein Fractions of Vitreous Preparations in Diagnostics of the Pressure of Death

The material of experimental approbation of the Muller-matrix mapping method of polycrystalline structure of vitreous preparations in the task of diagnosing its temporary necrotic changes is presented.

Yu. Sarkisova, V. T. Bachinskyi, M. Garazdyuk, O. Ya. Vanchulyak, O. Yu. Litvinenko, O. G. Ushenko, B. G. Bodnar, A. V. Dubolazov, Yu. O. Ushenko, Yu. Ya. Tomka, I. V. Soltys, S. Foglinskiy

Laser Autofluorescent Microscopy of Histological Sections of Parenchymatous Biological Tissues of the Dead

The results of experimental testing of the diagnostic capabilities of the method of spectral-selective fluorescence microscopy of temporary necrotic changes in histological sections of kidney internal organs are presented.

O. G. Ushenko, A.-V. Syvokorovskaya, V. T. Bachinsky, O. Ya. Vanchuliak, A. V. Dubolazov, Yu. O. Ushenko, Yu. Ya. Tomka, M. L. Kovalchuk

Statistical Analysis of Polarization Images of Histological Cuts of Parenchymatic Tissues in Diagnostics of Volume of Blood Loss

The results of polarization mapping of the distribution of the parameters of the Stokes vector of microscopic images of histological sections of parenchymal tissues of human organs in the problem of determining the level of blood loss are presented.

N. Sivokorovskaya, V. T. Bachinskyi, O. Ya. Vanchulyak, O. G. Ushenko, A. V. Dubolazov, Yu. O. Ushenko, Yu. Ya. Tomka, L. Ya. Kushnerik

Deep Learning in Processing Medical Images and Calculating the Orbit Volume

A software tool for calculating the volume of a soft-tissue eye orbit using the deep learning of neural network Mask R-CNN has been developed and tested. The result of the development will be in demand when evaluating the results of surgical intervention for the reconstruction of the thin bones of the orbit. It was established that the inaccuracy in constructing the contour of a soft-tissue orbit is 4–8%.

V. S. Asipovich, O. N. Dudich, V. L. Krasilnikova, A. A. Karakulko, A. L. Radnionok, P. A. Moroz, A. Y. Nikolaev, M. A. Konovalova, K. D. Yashin

Sleep-Related Epilepsy Diagnosis: Standard Video-EEG or Video-EEG Telemetry?

Video-EEG telemetry is a neurophysiological noninvasive method of investigation used for determination of electroencephalogram changes and semiology of paroxysmal events. In this study we aimed to investigate the diagnostic value of video-EEG telemetry in sleep-related epilepsy diagnosis. For this purpose, we have selected 115 patients (18.9 ± 1.3 years old, 71 males) with nocturnal seizures in anamnesis (witnessed level of diagnosis). All patients went through video-EEG telemetry and standard video-EEG according to the IFCN guidelines. The value of video-EEG telemetry was determined using real positive and real negative results. The real positive results of video-EEG telemetry turned to be 79.1% (91 patients), while 12% (14 patients) had no EEG changes in the standard video-EEG nor in video-EEG telemetry. In conclusion, the video-EEG telemetry has a high diagnostic value—79.1% in the diagnosis of sleep related epilepsy and should be performed in patients with nocturnal paroxysmal events.

V. A. Chiosa

A Real-Time WebGL Rendering Piepeline for MRI Using RayCasting Tranfer Functions

We present a way to integrate real-time multi-intensity transfer functions in a web browser environment using WebGL. We apply a two-pass rendering in order to establish the opacity and color of the given MRI recording. This pipeline helps viewing high resolution voxel domains and the adjustment of a transfer function for highlighting specific features types of a given DICOM recording. With recent advancements in the augmented and virtual reality domains medical imaging has become a center stage subject by brining the data closer to the patient and the doctor. Besides virtual reality, visualizing brain reconstructions is vital in brain mapping and neuro research. In conclusion we show a viable approach in rendering, processing and visualizing MRI data in real time in a Web browser.

R. Ciucu, F. Adochiei, I. Adochiei, F. Argatu, C. M. Larco, L. Grigorie

Alterations of Brain Structure Linked to Myoclonic Epilepsy

Recent neuroimaging studies suggest that frontal lobe and thalamus are the key structures involved in generation of myoclonic seizures. However, data indicating clear structural alterations of other grey matter (GM) regions in this seizure type is limited. Thus, our purpose was to characterize the cortical and subcortical volumes in patients with myoclonic seizures. We quantified brain structural measures (cortical and subcortical GM volumes) extracted from 3T magnetic resonance images (MRI) across 40 patients (mean age ± standard deviation: 25 ± 7 years; 14 males) with myoclonic seizures and 40 healthy subjects (23 ± 5 years; 14 males). A statistically significant difference in cortical volumes between patients and healthy subjects was found in the following clusters: left superior parietal, postcentral and fusiform; right middle temporal and bilateral precentral, superior frontal and precuneus areas (all p < 0.05). Analysis of subcortical volumes revealed significantly smaller volumes of bilateral thalamus and caudate in patients compared to healthy. These findings support the hypothesis of aberrant cortico-thalamic networks in patients with myoclonic seizures and extend these to basal ganglia.

A. Vataman

Bioinformatics

Frontmatter

Mode of Artemisinins’ Action on Oxidative Stress, Genomic and G-Quadruplex DNA

The present study was conducted to evaluate the effect of artemisinins’ on the level of lipid peroxidation (LPO), spontaneous chemiluminescence of the S-180 sarcoma homogenate and to study the nature of the interaction with canonical and non-canonical forms of DNA. Artemisinins are secondary metabolites of the medicinal plant Artemisia annua have anti-inflammatory, anticarcinogenic, immunomodulatory, antimicrobial, antihelminthic, antiviral, antioxidant and other properties. Our preliminary reverse virtual screening demonstrated that the ligand-binding domain of the human glucocorticoid receptor is the optimal target for artemisinin as well as for dexamethasone. However, the exact molecular targets and mechanisms of action of artemisinins are not well known. We have shown that the introduction of artemisinin leads to increase in LPO and chemiluminescence, which then causes apoptotic cell death in different ways without direct interaction with genomic DNA. We have also shown that artemisinin, dihydroartemisinin, and dimer of dihydroartemisinin interact with 2 sites of the G-quadruplex structure. Artemisinin and dimer of dihydroartemisinin are associated with a groove located between G15 and G21 while dihydroartemisinin binds to a groove located between guanine G5 and G23.

S. G. Ginosyan, G. V. Chilingaryan, H. V. Grabski, L. A. Ghulikyan, N. M. Ayvazyan, S. G. Tiratsuyan

Evaluation of the Quercetin Semisynthetic Derivatives Interaction with ABCG2 and Cyclooxygenase-2

Cancer multiple drug resistance and the inflammatory process are the main problems for successful chemotherapy. In anticancer therapy, plant and semisynthetic compounds are considered as potential modifiers for ABCG2 and COX2 inhibitors. As a result of experiments carried out in silico, the possible interaction of ABCG2 and inhibition of COX-2 by semisynthetic derivatives of quercetin were first revealed. The physicochemical parameters of the studied ligands were revealed, after which, for reliability, they were compared with in vitro experiments.

A. E. Manukyan

Information Analysis of Biochemical Parameters for Glucose Tolerance Tests

In the vast majority of existing methods of obtaining parametric biomedical information, it is represented by a finite set of informative parameters (features). Their informational significance is always different and practically not evaluated for the tasks of parametric identification and diagnosis of diabetes mellitus. In this paper, it is proposed to evaluate the informational significance of parameters (features) based on dispersion analysis of changes in their mathematical expectation with respect to residual noise. Fisher’s F-statistics were used as a quantitative measure of the changes, with the subsequent conversion of the obtained data into the amount of information expected based on the equations of the information measurement theory.

Y. I. Sokol, O. V. Chmykhova, V. V. Boyko, P. N. Zamyatin, D. P. Zamiatin

Medical Physics and Biophysics

Frontmatter

Theoretical Model of Lipid Peroxidation Kinetics for Complexes of Cytochrome c and Cardiolipin with Participation of Antioxidants

It is represented the kinetic model of lipid peroxidation process take place in the lipid membranes owing to a peroxidase activity of the complexes of cytochrome c and cardiolipine. The theoretical description of the studied kinetics includes two pathways: enzymatic and non-enzymatic, and takes into account the presence of direct-acting antioxidant: the molecules that act as the free radical scavengers, directly exhibiting a relatively high antiradical activity. The enzymatic pathway includes the reactions involving the complexes of cytochrome c and cardiolipin. The non-enzymatic pathway includes the reactions involving the free lipid radicals and antioxidant molecules. The obtained system of differential equations allows to simulate the kinetics of the lipid peroxidation process both accounting the inhibitory effect of the antioxidant and without it, and to test the antiradical activity of various types of antioxidants, as well as to find some unknown kinetic parameters by performing a comparison of the theoretical kinetic curves with the experimental ones.

E. Yu. Kanarovskii, O. V. Yaltychenko, N. N. Gorinchoy

Testing Green Silver Nanoparticles for Genotoxicity, Antioxidant and Anticancer Activity

The toxicity of the synthesized nanoparticles (NPs) by various physicochemical methods is one of the main problems for their application. NPs synthesized using plant extracts are less toxic than other methods of their congregation, so, in this regard, the synthesis of this so-called “Green NPs” is very important. Direct interaction of the AgNPs obtained from the 50% ethanol extract of Ocimum araratum with the genomic DNA of sarcoma S-180 cells by the method of retardation has been investigated. No genotoxicity of the stabilized green AgNPs has been detected, which extends its use in vivo. Testing of green NPs was carried out on outbred mice with S-180 induced sarcoma. The changes in the intensity of spontaneous chemiluminescence (SChL) of the homogenates of the tumor tissue of the S-180 sarcoma of all groups of mice were investigated. For evaluation of lipid peroxidation (POL), the formation of malonic dialdehyde (MDA) was determined using thiobarbituric acid (TBA-test), and the activity of superoxide dismutase (SOD) was measured for the activity of the endogenous antioxidant enzyme system. The highest values of SChL and MDA were observed in the experimental group, which was administered with a stabilized extract of AgNPs, compared with control animals. SOD activity increases both in the positive control group and in the experimental group. Since the formation of MDA is characteristic of lipid peroxidation reactions and the data obtained correlate with the results of SChL and SOD, it can be argued that AgNPs increase the level of ROS and cause damage of cellular structures and biopolymers, thus causing degradation of tumor tissue.

M. Petrosyan, T. Gevorgyan, G. Kirakosyan, L. Ghulikyan, A. Hovhannisyan, N. Ayvazyan

Influence of Polarization on Electron Localization in the Coated Tetramer Nanoclusters Used as Elements of Biorecognition Systems

A quasi-classical theoretical model is proposed for describing the localization dynamics of a common (tunneling) electron in the coated metal-organic nanocluster in an external low-frequency electric field, taking into account the electron-vibrational interaction and the polarization effects on its centers and on the ligand (organic) shell. The case of a square-planar tetramer nanocluster with the tunnel-connected centers is considered. This model allows a detailed study of the controlling role of the electric field, taking into account the contributions from the electron-vibrational interaction and from the polarization effects, in the realization of the various electron localization regimes, and reveals the ability of such a nanocluster to switch between them. This model is actual and suitable for the nanostructured composite systems of such kind, which are widely used as the basic elements in the bio-recognition systems.

E. Yu. Kanarovskii, O. V. Yaltychenko

Use of Physical Methods as an Element of Complex Treatment of Burn Wound Microbiome

According to World Health Organization, burns remain a high priority matter of medicine as the third in the overall structure of traumatism. One of the main causes of death from burn injuries is infectious complications, which require the use of effective antimicrobial agents. In view of the increased resistance of microorganisms to antibiotics, it is expedient to find alternative ways of antimicrobial control, one of which is the use of low-intensity current without external power supplies. This is exactly the purpose of our study. The obtained results allowed to confirm the antimicrobial effect of low-intensity currents without external supplies on the example of a clinical strain of methicillin-resistant Staphylococcus aureus in a closed and open electrical circuits with the need for further research in this direction.

V. Nagaichuk, R. Chornopyshchuk, O. Yunusova, M. Onyshchenko

Molecular, Cellular and Tissue Engineering

Frontmatter

Interaction of Quercetin with LasR of Pseudomonas aeruginosa: Mechanistic Insights of the Inhibition of Virulence Through Quorum Sensing

Pseudomonas aeruginosa is one of the most dangerous superbugs for which new antibiotics are urgently needed. This bacterium forms biofilms that increase resistance to antibiotics and host immune responses. Current therapies are not effective because of biofilms. Biofilm formation is regulated through a system called quorum sensing, which includes transcriptional regulators LasR and RhIR. These transcriptional regulators detect their own natural autoinductors. It is known that quercetin inhibits Pseudomonas aeruginosa biofilm formation, but the mechanism of action is unknown. In the present study, we tried to analyse the mode of interactions of LasR with quercetin. We show that quercetin has two binding modes. One binding mode is the interaction with ligand binding domain. This interaction is not competitive and it has been shown experimentally. The second binding mode is the interaction with the “bridge”, that involves amino acids form ligand binding domain, short linker region and DNA binding domain. This part has not been shown experimentally, because LasR protein is not soluble. In our model the hydroxyl group of ring A interacts with multiple leucines during the second binding mode. This study may offer insights on how quercetin inhibits quorum sensing circuitry by interacting with transcriptional regulator LasR.

H. V. Grabski, S. G. Tiratsuyan

Mechanical and Morphological Characterization of Decellularized Umbilical Vessels as Tissue Engineering Scaffolds

Cardiovascular diseases are the number one cause of morbidity and mortality globally. Numerous pathophysiological modifications that develop are associated with the stenosis and occlusion of blood vessels and tissue damage due to inadequate nutrient supply. Despite a variety of therapies available today, the preferred treatment for the long-term revascularization is artery bypass surgery. The autologous vessels are considered the “gold” standard treatment for this category of patients; unfortunately, they are often unavailable due to comorbidities or unsuitable for use. Synthetic scaffolds are suitable in large-diameter arteries (>8.0 mm) and medium-diameter arteries (6.0–8.0 mm), but are of limited use in small-diameter vessels (<6.0 mm) due to poor patency rates. However, tissue engineering may be an option to overcome the existing practical issue. Thus, tissue engineered vascular grafts (TEVGs), namely decellularized matrix, are suggested to present an appropriate graft alternative; as a result, increasing interest is dedicated to this field. By decellularization the loss of major histocompatibility complex (MHC) is induced. Consequently, the risk of development of an immunological response by the host is reduced. Undoubtedly, the acellular scaffolds have a lot of advantages. There are reports about different decellularization techniques already, such as physical, chemical and biological methods. Unfortunately, information about combination and comparison between them are not sufficient. This study aimed to contrast three different methods (the enzymatic method with 0.25% trypsin; the chemical method with 1% SDS and the combined method with 0.25% trypsin and 1% SDS) to decellularize umbilical vessels as a TEVG of a small diameter and test histological and physical properties. In addition, a short overview of advantages and disadvantages of existing protocols is also presented.

T. Malcova, L. Globa, A. Vascan, E. Țugui, A. Stoian, V. Nacu

The Procedure of Bone Cells Obtaining, Culture and Identification

Isolation of bone cells represent a major importance in laboratory research and clinical practice. This work was conducted on six 6 ± 1.5 months Wistar rats from which the diaphysis of long tubular bones were harvested, followed by mechanical removal of all tissues excepting the bone tissue with further chopping. The chopped bone tissue (ChBT) was processed by two ways, each of them was followed by two methods of bone cells isolation and culture: through explant and enzymatic digestion. Obtaining of bone cells through the explant method in both ways, was more effective compared to enzymatic digestion. Also, there was no significant difference between the amounts of cells obtained between both bone processing protocols. The obtained bone cells were identified following morphological changes and Alizarin red staining after cells culture in over-confluence.

M. Jian, V. Cobzac, A. Mostovei, V. Nacu

Evaluation of the Endothelial Cell Regenerative Proprieties of the Cornea in the Culture Media. Results and Prospects

Preservation of the endothelial viability of the cornea is one of the main problems of the non-proliferative corneal transplantation, which creates a well-maintained status with the peripheral cell density decreasing throughout the life, about 30% higher than in the center of the cornea. The disruption of connections between cells adherent junctions correlates with a rapid decline of the proliferation of endothelial monostratified cells during the in vitro culture. The nutritional environment supplemented with EDTA proves that it has the ability to break the adherent junctions of the intercellular endothelial cells. The most widely used method of preservation is the cultured Tissue, “C”. It provides for the endothelial cells viability for 45 day.

A. Cociug, O. Macagonova, V. Cusnir, V. Cusnir, V. Nacu

The Influence of Semiconductor Nanoparticles Upon the Activity of Mesenchymal Stem Cells

In this paper, we report on the viability and proliferation of mesenchymal stem cells after exposure to different types of semiconductor nanoparticles. The nanoparticles used for the tests are based on GaN thin layers grown on commercial ZnO and ZnFe2O4 nanoparticles. Different quantities of nanoparticles incubated with mesenchymal stem cells influence the metabolic activity of cells, which was assessed by the MTT assay. The cytotoxic effect of ZnO nanoparticles on MSC was demonstrated and no harmful effect of the other materials.

T. Braniste, V. Cobzac, P. Ababii, I. Plesco, S. Raevschi, A. Didencu, M. Maniuc, V. Nacu, I. Ababii, I. Tiginyanu

Clinical Engineering, Health Technology Management and Assessment

Frontmatter

Medical Devices Regulations, Management and Assessment; New Trends New Needs

In the accelerated way that Medical Devices (MDs) are developed and revolutionize health care delivery during the last decades, Regulation, Management and Assessment of Health Technology are of paramount importance. This paper provides a short overview of the recent development in this area and discusses some issues related to the new EU regulatory framework on MDs, the need for a more rigorous management and the importance of Health Technology Assessment for MDs. Study is also focusing on the particular characteristics of MDs that impose a different approach, in these three domains, compared to medicinal products, in order to get the expected benefits right to the patients, in a safe and cost-effective way.

N. Pallikarakis

Assessment of Human Tissue Transplantation Activities in the Republic of Moldova

The assessment of human tissue transplantation activities in the Republic of Moldova highlights the tissue transplant service as a component part of the national transplant system in the Republic of Moldova. Strengthening the national transplant system and continuous development of the human tissue transplant service has resulted in a significant increase of efficacy of deceased donation process. Implementation of performance indicators for institutions authorized to carry out donation and procurement activities from deceased donors will allow performing the audit of donation and transplantation.

T. Timbalari, I. Codreanu, O. Lozan, V. Nacu

Electro-Acoustical Examination in Noninvasive Monitoring as a Basis for Treatment Selection

Early detection of otitis media and adequate treatment in small children prevent from chronic middle ear disease and complications development. The purpose of this article is to determine the role of the noninvasive electro-acoustical examinations in treatment modality selection in prolonged otitis media forms. Impedance audiometry, brainstem evoked response audiometry and registration of otoacoustical emissions were used for early detection of middle ear pathology and for monitoring of children. Monitoring of small children confirmed high rate of otitis media in this age group. Correct interpretation of the diagnostic tests results, analysis of risk factors background and electro-acoustical monitoring present the basis for differentiation between short-duration otitis media forms and prolonged forms. Any modification of impedance audiometry results in a child with risk factors is indication for further electro-acoustical monitoring of middle ear. Prolonged forms of otitis media in children are treated by ear surgery—myringotomy with tympanostomy tube insertion. Post-surgical electro-acoustical monitoring gives the information of middle ear status and function and is useful in prognosis of otitis media evolution. Post-surgical electro-acoustical monitoring showed the advantages of tympanostomy in children especially in modified version.

S. Diacova

Functional and Morphological Correlations in Prolonged Otitis Media in Childhood

Recurrent and persistent otitis media (OM) in childhood are characterized by prolonged and clinically different courses. The aim of this work is to study functional and morphological features in children with prolonged OM forms. Children with persistent OM with effusion and recurrent acute OM were examined by impedance audiometry, brainstem evoked response audiometry, registration of oto-acoustical emissions, pneumatic otoscopy, otomicroscopy, computer tomography and examination of surgical findings. Surgery consisted of modified version of tympanostomy. Otomicroscopical, cytological and histological examinations revealed the presence of morphological changes characteristic for chronic inflammation in part of recurrent and persistent OM. Duration of the process (more than 3 months) and previous treatment (physiotherapy and adenoidectomy) correlated with chronic changes in both groups. Prolonged OM forms present interrelated stages of the common inflammatory process in the middle ear. Functional changes, indicating the presence of OM for more than 3 months are the basis for comprehensive treatment, including tympanostomy. Modified tympanostomy permits better evacuation of pathological content from tympanic cavity and improves evaluation of morphological changes.

S. Diacova, I. Ababii, L. Danilov, M. Maniuc, P. Ababii, V. Gavriluta, A. Levcenco

The Review of Bipolar Ion Mobility Spectrometers

The review considers the design of ion mobility spectrometers, which allow for the conditionally simultaneous detection of both positive and negative ions. The review of existing serial ion mobility spectrometers with simultaneous detection of substances in both spectrometric modes is carried out. The ways of realization of the bipolar ion mobility spectrometer are analyzed.

Y. R. Shaltaeva, A. V. Golovin, V. K. Vasilyev, E. A. Gromov, M. A. Matusko, E. K. Malkin, I. A. Ivanov, V. V. Belyakov, V. S. Pershenkov

Assessing the Safety of Using Incubators for Newborns

This paper presents an analysis of the risks of using the incubator for newborns. In order to use the incubator safely, we must evaluate the risks related to its use, to identify how the patient will be influenced in different circumstances. For evaluation, the criteria have been established that can directly or indirectly influence the quality of the medical act as well as the safety of the user and the patient, the criteria are such as: the age of the medical devices, the degree of use, the people in charge of preventive maintenance, the type of preventive maintenance, the number of users who operate the medical equipment. The basic causes of the occurrence of the incidents are the technical defects, their faulty and incomplete calibration, the lack of preventive maintenance as well as the effects of the human factor on this process.

C. Pislaru, V. Șontea, S. Railean

Health Informatics, e-health and Telemedicine

Frontmatter

Creation of Regional Telemedicine Diagnostic and Treatment Complex

Given the extreme prevalence of cardiovascular diseases, which have recently has become an epidemic and are the main cause of death, early diagnosis and detection of diseases at the initial stage with subsequent monitoring of the condition of patients is of great importance. The creation of modern high-performance telemedicine diagnostic and treatment complexes to solve these problems should be based on modern advances in telecommunication and medical technologies, and modern methods of designing complex radio engineering geographically-distributed systems.

K. V. Kolisnyk, R. S. Tomashevskyi, T. V. Sokol, S. M. Koval, D. M. Deineko

Telemedicine—Advanced Technology at the Service of Society

In the conditions of the information society advanced technologies penetrate into different spheres of human activity, including medicine. In the medical field, three branches of telemedicine have already been formed: synchronous telematics, asynchronous telemetry and remote monitoring. Economic calculations demonstrate the efficacy of telemedicine that has benefits for the entire society, both for healthcare beneficiaries and their providers.

E. Arama, S. Maximilian, L. Rotaru, V. Vovc

Biomedical Engineering Education

Frontmatter

Static Analysis of the Human Body Balance Following an Induced Vertigo

This paper is aimed towards a static evaluation of the human body balance, on a force platform such as Kistler platform, following an induced vertigo by spinning the subject. Vertigo is the feeling of spinning even when the person stays in place. The environment seems to move vertically or horizontally. Some people feel like they’re spinning. The effect may be easy or hardly noticeable, or it may be so severe that the subject may fall to the ground. Vertigo is more severe than dizziness, described as a slight uncertainty in orthostatic position. Dizziness can make the movement difficult, as the feeling of rotation affects the balance. The recorded values were acquired at a frequency of 100 Hz for 30 s, which led to the recording of 3000 values for every different parameter. A specialized numerical analysis software, Interactive Data Language (IDL), was used for the realization of the graphs and the statistical analysis of the results obtained on the Kistler force platform.

I. Şerban, C. Drugă, A. Tătaru, B. Braun

Innovation, Development and Interdisciplinary Research

Frontmatter

Voltage Management of a Remote Load

Accurate regulation and measurement of a load parameters can be difficult when there are significant voltage drops between the power supply and the load. In particular, some methods of the load voltage management or regulation are known. These methods have these or those disadvantages. A new power supply method is offered for the remote load. This method is based on correction of the power supply output voltage by using an invariant relationship of the line. The affine ratio of three points, known in projective and affine geometry, is such invariant. Therefore, three samples of the output voltage and the corresponding samples of the input current are used. The affine ratio value does not depend from the line parameters and the measurement accuracy.

A. Penin, Yu. Savva, A. Sidorenko

Steady-State Behaviors of a Quantum Oscillator Coupled with a Three-Level Emitter

A laser-pumped three-level Λ-type system the upper state of which is being coupled with a quantum oscillator characterized by a single quantized leaking mode has been investigated. Two distinct situations leading to lasing effects of the quantum oscillator’s degrees of freedom have been identified and the mechanisms behind them have been described. Particularly, the interplay between single- or two-quanta processes accompanied by quantum interference effects among the induced emitter’s dressed-states responsible for flexible lasing effects has been proved, respectively.

A. Mirzac, M. A. Macovei

Integration of Cyber Security in Healthcare Equipment

The expansion of digital technologies in operational technologies (OT) has significantly supported the development of new features and capabilities. However, the integration of information technologies (IT) in such environments, has also led to the inheritance of cyber security risks. This has also created new potential operational risks due to the fact that operations are controlled by a computer or digital device. Most of the equipment, such as from healthcare, that has IT systems embedded and performing certain processes, is subject to vulnerabilities and prone to cyber-attacks similar to computers. The developing capabilities and integration of IT in various operations offers the capability to introduce new features and monitoring capacity that were not possible before, or had a very high cost. The applications and integrations are countless, and do bring improvements for the society, both for the healthcare providers, as well as for the patients. However, the healthcare systems were designed with the focus on operation and safety. The security concept was not always known or taken into account due to the technologies used before. In addition, if we refer to healthcare equipment that uses nuclear or radiological sources for treatment, then safety, as well as security, should be of core importance. Even if there are certain cyber security prevention or monitoring capabilities that are possible to be enabled in some devices, these were not always used due to the perceived high risk of an operational risk. Recent research has proven that the compromise of an OT via a cyber security attack is possible, and thus, security controls and mitigation are not to be neglected anymore [1]. In this paper we will look into the current issues that cyber security risks could create to operational technologies, with a focus on the healthcare sector.

Au. Buzdugan

Cyber-Physical Systems—Nanomaterial Sensors Based Unmanned Aerial Platforms for Real-Time Monitoring and Analysis (Invited Paper)

In the new and transformative era, our surrounding environments are increasingly connected through exponential growth of cyber-physical systems and intelligent technologies. One such example is an Unmanned Aerial Surveillance Platform, also known as drone, for applications such as surveillance, real-time monitoring, emergency augmentation for actionable response, security and enabler of connected communities to bring about new levels of opportunity and growth, safety and security, health and wellness, thus improving the overall quality of life. Based on our previous experience, we present a modality of smart and connected sensors platforms that have a great potential to provide enhanced situational awareness for safety and security.

A. Vaseashta

Bibliometric Analysis of the Nanotechnology Research Area in the Republic of Moldova

A bibliometric analysis was performed to evaluate nanotechnology research area in the Republic of Moldova during ten years, 2009–2018. For comparative purposes, the results were benchmarked against the findings of Germany, France, USA, China, Japan, Romania, Russia, and Ukraine. In our research, it was found that the Republic of Moldova holds the first places in the world on two StatNano indicators: national priority and local share in nanoscience, and the fourth position in the world on the number of nano-articles per GDP. Investigations results show that Moldovan nanoscience is defined by a high level of share of international collaboration, the number of nano-articles per million people corresponds to the average figure worldwide and the medium citation per nano-article within the investigated countries is almost at the same level as for Japan. Study of collaboration patterns enables us to identify the active collaborative networks among the scientists from the Republic of Moldova and Germany, USA, Russia, France, Romania. Analysis of the total number of citations to nano-articles and h-index shows that the Moldovan nanotechnology scientific community needs to work on improving its research impact.

A. I. Rosca, I. P. Cojocaru, A. Gh. Turcanu

Qualitative Method to Control Toxic Impurities in Drinking Water

This paper presents the capabilities of the laser spectroscopy method for monitoring the concentration of dissolved organic impurities of toxic substances. The method of laser fluorometry that is based on the principle of calibration of the fluorescence signal of a dissolved matter to the internal standard—the Raman scattering signal of water, allows performing a quantitative assessment of the presence of harmful impurities. This method proves to be very promising due to its accuracy and expressiveness. The sensitivity of this method is sufficient enough to detect concentrations of the majority of studied specimens dissolved in water that exceed MCL. The effect of UV light exposure on some specimens was studied as well.

O. Kulikova, A. Siminel, A. Micu, N. Siminel

The Cathepsin D as a Potential Biomarker for Survival Rate in Polytrauma. Pilot Research

Trauma represents a major problem affecting the younger part of humanity as shown in several studies. It represents the main cause of deaths or disabilities that could be prevented in children, teenagers and adults younger than 44 years. In Republic of Moldova, trauma has the fourth place after gastrointestinal tract diseases in list of death causes. One of the most complicated and hard to explore domain of trauma is the polytrauma. Except tardive consequences regarding recovery period and other clinical, economic, and social burden aspects of polytraumatized persons, the immediate effects on the patient have a crucial role on patient’s life. This is why numerous researches are trying to reveal the key moments and factors in pathogenesis and clinical management of polytrauma patients. Scientists are looking for some predictive models that could estimate the death/survival rate of traumatized/polytraumatized population of patients. Some of these models seem to be based on concentration dynamics of different biomarkers in posttraumatic period. Cathepsin D is one of this enzymes studied in this trial. Using logistic regression technique, it was created a predictive model estimating polytraumatized patients’ survival probability based on plasma Cathepsin D concentration (CDEA) at 3 and 48 h after traumatic injury.

O. Arnaut, S. Sandru, A. Sauleal, I. Grabovschi, Gh. Rojnoveanu

Comparative Study of the p-CdS/n-CdTe Photovoltaic Devices with Depleted Intrinsic Layer

In fabricating CdS/CdTe photovoltaic devices by close space sublimation method, thermal annealed in CdCI2 ambient at 400 °C at the interface is deposited an i-CdO layer by magnetron sputtering. Comparative analysis of electrical, photovoltaic parameters and photo-response spectral distribution is studied. The insertion of i-CdO at the interface of device increases both short circuit current (Isc) and open circuit voltage (Voc). In addition, the experimental results revealed that the insertion of i-nanolayer broaden the depletion region of the device and diminish the interface state density, thus improving efficiency of the device.

A. Al Qassem, L. Gagara, V. Fedorov, I. Lungu, T. Potlog

Synthesis and Biological Properties of the Novel Coordination Compound with Rhodanine-3-Acetic Acid

The new coordination compound based on rhodanine-3-acetic acid was synthesized, characterized and evaluated as potential antimicrobial agent on a panel of bacteria and fungi. The structure and stereochemistry of the novel 1D coordination polymer [Zn(5,5′-Rda-Rda)(dmf)2(H2O)2]n (1) have been characterized by single crystal X-ray structure, IR- and NMR-spectra.

A. Vitiu, D. Chişca, E. Gorincioi, E. Coropceanu, P. Bourosh

Phenomena of Radiative Recombination in Single Crystals of Cadmium Thiogallate with Cadmium (CdGa2S4:Cd) or Sulfur (CdGa2S4:S) Excess

The experimental results related to the influence of non-stoichiometry on the emission spectra of CdGa2S4 single crystals exited by accelerated electrons are presented. Cadmium thiogallate single crystals with the excess of cadmium or sulfur were prepared by the method of chemical transport reactions with iodine, and the cathodoluminescence spectra of CdGa2S4:Cd and CdGa2S4:S were studied. A model of energy levels and optical transitions for this compound is proposed.

E. Arama, V. Pantea, T. Shemyakova, V. Vovc

Design and Evaluation of a Low Cost Electrical Muscle Stimulator (EMS) with Biopac

The present paper is aimed towards designing a low-cost electrical muscle stimulation device and evaluating the muscle activity using high performance electromyography device, BIOPAC. The electrical muscle stimulator is essentially an electronic device which has the ability to contract the muscles via electrical current sent to the electrodes. The power of the device is provided by a 9 V battery, which ensures the portability of the device. The electrical muscle stimulation is provided mainly by two timers that are designed to carry electrical impulses and count them, a transformer, a LED that monitors the transmission of the impulse and three potentiometers which are used to change the length, the duration and the amplitude of the impulse that will be sent to the muscle via electrodes. This type of electronic device addresses patients with cervical spine pain, to increase muscle strength, warming and relaxation. By using this EMS device in certain pathologies of the neck, the patients are able to relieve neck pain without using medication. Biopac is used for evaluating and monitoring differences between a natural and an electrical stimulated contraction.

I. Şerban, C. Drugă, I. Tătulea, B. Braun, R. Necula

Development of the High-Resolution Scintillator Type Imager Using Si GRID Structures

The scintillator type X-ray image detector is being developed in this paper. The spatial resolution of this detector is not so higher than direct conversion type x-ray image detector because of scattering of luminescence of scintillator in the detector. The diffusion of light emit of scintillator by X-ray irradiated was suppressed by processing the silicon substrate using microfabrication technology. These small hole patterns were machined in a silicon substrate, and the scintillator was filled in the silicon grid holes. These holes reflect the light emitted by the scintillator and suppresses diffusion. The scintillator can be optically separated by this device. And these structures are operated as one detector. The purpose of this study is to prove that the silicon grid structures improve the spatial resolution of the scintillator type detector. Therefore, we measured the spatial resolution of the scintillator using this Si grid structures. In this study, CsI:Tl was buried in grid holes by the melting method. The spatial resolution of the sample in which CsI:Tl was deposited into the inside of the grid structure was measured. From this result, the deposition of the scintillator in the Si grid structures using the melting method has led to an improvement in spatial resolution of the scintillator type X-ray image detector.

K. Tabata, R. Ohtake, J. Nishizawa, A. Koike, T. Aoki

Packing Conditions of Optical Separated CsI:Tl Scintillator by Silicon Collimator

We have been developing a scintillator type X-ray imaging detector. The spatial resolution of this type detector is lower than that of direct conversion type detectors. This is because X-ray scintillation light spreads in the scintillator. To settle this issue, we proposed optical separations of scintillator by a silicon collimator, which is a silicon substrate processed into grid structure by the semiconductor micro processing technology. The silicon collimator which is filled with scintillators works as an X-ray imaging detector by joining with a photodiode array. In this study, melted Cesium Iodide doped with Thallium (CsI:Tl) was poured into the silicon collimator, and recrystallized. After that, Packing conditions of CsI:Tl in the silicon collimator were observed by Scanning Electron Microscope (SEM) and Computed Tomography (CT). These results suggested that holes on the silicon collimator was closely packed with CsI:Tl. An image of recrystallized CsI:Tl under X-ray irradiation was acquired. From this image we confirmed that CsI:Tl which was recrystallized in the silicon collimator emitted visible light by X-ray excitation. The pixel separation effects of the silicon collimator for light spreading was also confirmed. Moreover, a relative standard deviation of pixel value of the fabricated sample was lower than that of a sample made by the vacuum evaporation method in the previous study. This result indicated that uniformity of luminescence was improved.

R. Ohtake, K. Tabata, J. Nishizawa, A. Koike, T. Aoki

Study on Ferroelectric Thin Film Capacitor for AC-Coupled CdTe X-ray Detector

We present that fabricating ferroelectric thin film capacitor on electrodes of the X-ray detector to make AC-coupled CdTe X-ray imager. In order to determine the capacitance required for the coupling capacitor, radiation spectrum is measured by using some coupling capacitor have different capacitance. As a result, it was found that the more the capacitance is large, we can get correct radiation spectrum. Because small capacitor with large capacitance is required, BaTiO3 is selected as a high dielectric constant material. We fabricated a ferroelectric thin film capacitor with an area of about 48 μm2 and a thickness of about 100 nm by sputtering. As a result of measurement, the capacitance is about 880 pF, and the tendency of variation of dielectric constant with frequency corresponded with past paper. Although the dielectric constant was significantly smaller than the BaTiO3 film in the papers. We considered that the main issue is quality of BaTiO3 film. Quality of film is increased by depositing under high substrate temperature. Performance of CdTe as a radiation detector is deteriorated by high temperature. Therefore, we need to consider the way to deposit BaTiO3 on CdTe at low substrate temperature.

M. Hayakawa, H. Nakagawa, K. Sakaida, T. Aoki

Aluminium-BSF Versus PERC Solar Cells: Study of Rear Side Passivation Quality and Diffusion Length

The impact of (bulk) material and rear surface (contact) quality to the efficiency is found to be quite hard to measure on a processed solar cell. We will show with this paper that CELLO (solar cell local characterization) photo-impedance-spectroscopy measurements are capable of separating bulk from rear side effects on locally resolved maps. This study focuses on multicrystalline Aluminium-BSF solar cells which have been produced according to a co-firing parameter optimization process with a wide parameter space. It is found that the rear side recombination velocity on some locations of the Al-BSF cell is much better than compared to PERC cells. Thus, the full potential of Al-BSF solar cells is much higher than usually expected and anticipated. In the future paste and co-firing optimizations are required to transfer the excellent local values of Al-BSF cells to the full cell area for excellent global values that result in cell efficiencies higher than today PERC solar cells. Thus, the time of Al-BSF solar cells is for our opinion not over yet.

A. Schütt, O. Lupan, R. Adelung

Smart Device for Therapeutic Hypothermia

We describe the construction of a non-invasive hypothermic system for reducing brain temperature used in the treatment of stroke. The device is used by those who offer first medical aid. Its usage helps with the stabilization of the patient’s state and stops any aggravations.

V. Cojocaru, R. Galus, T. Fedorisin

Make Innovation Happen: Scientific and Statistic Tools to Accelerate the Way Toward Technology Readiness Level TRL 9—A Deployed Application

We consider some tools/methodologies, scientific and statistics based, to design and optimize technological processes and the resulting products, by providing finally a robust design. Being implemented in R&D labs, such tools and methodologies could enable a faster skip from lab experiments to real world (i.e. Technology Readiness Level TRL 9) by catalyzing innovation, problem solving and even discovery. At the end of the day to make innovation happen. We present also a successful example of application of such approach, to open also a larger discussion about the opportunity of intensively using such approach for nano scale organized materials and further products, with application also in biomedical engineering. An usual cause for the difficulty of R&D labs to pass over the TRL 4 (=technology validated in lab) is the approach of testing the realized prototypes in the R&D lab, i.e. not taking into account the effective manufacturing conditions and environment, and the further operation conditions for the proposed and developed concept/product/device. To overpass that, the best practice shows the research scientists/engineers need to find from the beginning of the research and the development process the effective future manufacturing conditions/process parameters and the future real-life utilization of the resulting products (operating conditions) and to test their prototypes in such conditions. But more than only testing, it is crucial to provide a so called “robust design” (Taguchi), i.e. to optimize the concepts/products parameters so they perform to expectations under a wide range of operating conditions, meanwhile being possible to be fabricated at lower possible cost and risk.

N. Varachiu

Investigation into Interlayer Water Structure in Na+- and Ca2+-Montmorillonite: A Molecular Dynamics Study

Swelling clays play significant roles in current industry. Molecular dynamics simulations have been performed to investigate the swelling properties, hydration behaviour and mobility of interlayer molecules of Na+- and Ca2+-montmorillonites. More specifically, to characterize the structure and energetics of Na+ and Ca2+ adsorption as functions of water content; the relationships between the coordination environments of clay surface–interlayer water–exchangeable cations; the influence of cation hydration energy on the dynamics and swelling mechanism of clays; and the influence of charge distribution on all of the above. Establishing an understanding of these clay/water systems is viewed as a sensible foundation for the more complex systems.

N. Siminel

A Positioning Mechanism Based on MEMS-INS/GPS and ANFIS Data Fusion for Urban Life Mobility Improvement

To achieve a positioning mechanism for urban life mobility improvement, a signal processing algorithm was tuned, using an ANFIS (Adaptive-Neuro-Fuzzy-Inference System) data fusion algorithm, with the experimental data collected from platforms equipped with Inertial Measurement Units (IMU) based on MEMS sensors and GPS receivers. In the paper’ sections are presented the following aspects of interest: the MEMS-INS/GPS (a GPS unit and a miniaturized Inertial Navigation System) structure and functioning, the fuzzy inference system training procedure, the data evaluation of the proposed structure using experimental data and the testing results. The after-training evaluation of the FISs denoted absolute mean deviations between the reference data and the fuzzy models by order of 10−5 degrees for latitude and longitude channels, of 10−1 m for the altitude channel and 10−1 m/s for all three-speed channels.

L. T. Grigorie, N. Jula, C. L. Corcău, I. R. Adochiei, C. Larco, S. M. Mustaţă

Scattering Indicatrix for Absorbing Porous Medium with Dark Modes

A mathematical model for calculation of the scattered radiation by a highly absorbing porous medium with dark modes is proposed. The contribution of the scattered light from two areas with the same slope was taken into account. It is shown that the previously discovered anomalous retroreflection phenomenon can be observed only in the case when in the porous material the interface between the medium and the vacuum is maintained.

V. V. Sergentu, E. V. Monaico, V. V. Ursaki

Static Versus Novel Dynamic Biofouling-Testing of Fouling-Release Coatings for Marine Applications: Pros and Cons

With increasing numbers of seaborn transportation of goods worldwide, the exploitation of the ocean is rising. More and more ships and marine equipment with biocide-containing antifouling coatings are in contact with the ecosystem “ocean”. The development of environmentally friendly coatings preventing or allowing a management of biofouling is therefore an urgent issue. To achieve this aim, it is essential to have access to appropriate immersion testing methods to evaluate the fouling-release properties of novel coating systems under most realistic conditions. In this study, a novel dynamic biofouling-test stand was designed and constructed to simulate the movement of a ship and to provide a reproducible testing method for marine coatings. Mechanically durable and environmentally friendly polythiourethane (PTU)/tetrapodal zinc oxide (t-ZnO) microparticle composite as well as reference materials such as AlMg3 alloys and pure polydimethylsiloxane (PDMS) were immersed in the Baltic Sea under static and dynamic conditions for 22 weeks. Strong differences in the degree of biofouling subjected to those conditions were found.

H. Qiu, I. Hölken, A. Gapeeva, R. Adelung, M. Baum

Comparison the Marginal Fit of Metal Coping Cast Made Through Different Methods

The present work the evaluation and comparison of the marginal fit of chromium-cobalt (Cr–Co) copings fabricated through three different methods are investigated. There are some technical factors that we cannot get less than 40–50 μm for marginal adaptation. The marginal gap in case of traditional methods is smaller than digital ones, even so the gap produced by the DLMS was not significantly greater and it was not exceeded the clinically acceptable range. Taking into account the advantages of DLSM, it is superior to traditional methods.

A. Badarau, A. Gumeniuc, E. V. Monaico

Synthesis of New Zinc Phthalocyanine with Block Copolymers in Nanomedicine Applications

Synthetic routes towards new conjugates of hydrophilic zinc phthalocyanine (ZnPc) with N-vinylpyrrolidone (NVP) and acrylic chloride (ClAC), are described. For this purpose, a copolymer of N-vinylpyrrolidone (NVP) with acrylic chloride (ClAC), according to the Friedel-Kravts method, was grafted to the benzene nucleus of zinc phthalocyanine (ZnPc). The paper contains the analysis of polymer analogs of NVP-ClAC-ZnPc with IR and UV-VIS spectroscopies.

P. Tiuleanu, S. Robu, V. Prisakari, V. Furtuna, R. Rusnac, T. Potlog

Portable Campimeter to Evaluate Visual Field Modifications of Subjects with Low Vision State

The low vision state that can be installed at the visual function level causes a change in a series of important visual system parameters, as well as a decrease in the quality of life of human subjects. Mostly, lowering the visual function level should be evaluated periodically in any kind of condition (at home, medical clinic or screening center) and in all cases the investigator optometrist should identify the situations in which subjects develop visual field limitations. These visual field limitations may indicate the onset of a wide range of ocular pathologies, which, if detected early, can control procedures of management evolution or even improve with various visual aids. In the first part of the paper are presented some general aspects regarding the field of vision and also its parameters to the human visual system. The second part describes the construction of a visual field assessment system based on the primary requirement of being portable and easy to use device. In the final part of the paper are presented the results obtained using this visual field evaluation device and the way it can be programmed for several types of evaluations.

M. I. Baritz, M. G. Apostoaie, A. M. Lazar

Nanotechnological Aspects at Electro-activation of Secondary Dairy Products

The study of the electro-activation processing of whey, with the recovery of the PMCs and simultaneous isomerization of lactose into lactulose, reveals the necessity of certain technical requirements in order to ensure management and control of a technological process that takes place in an electrolyzer. Electro-activation of secondary dairy products and obtaining protein mineral concentrates (PMCs), with the simultaneous isomerization of lactulose allows not only to specifically mobilise proteins at the formation of protein compounds but also isomerization of lactose into lactulose. As is well known, a lactulose molecule is about 5 nm. Whey, a secondary dairy product, has over 200 components, a part of which are in nano-quantities. Electro-activation triggers a number of inter- and intramolecular reactions at the nanoscale level. The results may be of interest for dairy factories that can use the proposed installation and apply the whey processing wasteless technology and for other food industry companies, as well as for those in pharmaceutics—in valorification technologies for obtaining the PMCs with the desired content of protein fractions and amino acids.

E. G. Vrabie, M. K. Bologa, I. V. Paladii, V. G. Vrabie, A. Policarpov, V. Gonciaruc, C. Gh. Sprincean, T. Stepurina

Nuclear and Radiation Safety and Security

Frontmatter

Evaluation of Radiation Hardness of the Bipolar Devices in the Space Conditions

Real time dependence of operation temperature, which is typical for space environment, was taken into account in the numerical simulation of radiation degradation of LM111 bipolar voltage comparator input current. The technique and results of performed numerical analyses are presented and discussed.

A. S. Rodin, A. S. Bakerenkov, V. A. Felitsyn, V. S. Pershenkov, V. A. Telets

Integral Estimate of LSI Radiation Hardness as a Fuzzy Number of Multiplicity of Nodes

The analysis of the LSI behavior under radiation exposure at functional and logical level of description was carried out. It is shown that there are deterministic and non-deterministic failures typical when exposed to ionizing radiation. In the first case, the behavior of complex devices is determined by the specific ratio of the radiation-sensitive parameters of the elements, in the second case—the statistical variation of the failure threshold levels for the same type of samples.

V. M. Barbashov, N. S. Trushkin, A. K. Osipov

Revision of the Curriculum on Nuclear Safety and Security in the Light of Recent International Recommendations

The University is the place where it is necessary to further develop the foundations of what we have come to call the general culture. The issue of non-proliferation is not studied as a special discipline at any University in Moldova. To fill this gap, the National Nuclear Security Support Centre of the Technical University of Moldova has developed and introduced a new optional curriculum (ECTS 4) that reflects the synergy of security, safety and safeguards (3S). Because 3S is inextricably linked, the updated curriculum makes the master students aware of the actuality and need for nuclear non-proliferation policy. Cybersecurity that has become a pillar for every on 3S components is also reflected in this optional curriculum. This optional discipline was introduced to the Master of Science in Microelectronics, Nanotechnologies and Biomedical Engineering because nuclear or radioactive materials are parts of microelectronics and also largely used in medical investigations and treatments. The evaluation showed that master’s students have higher knowledge of non-proliferation than graduate license holders.

Ar. Buzdugan, Au. Buzdugan

National Nuclear Security Support Centre and Non-proliferation of Weapon of Mass Destruction

The paper reviews the need of customs control for dual-use goods and services, including those that belong to medicine, pharmaceuticals, and micro-nanoelectronics. In this regard, a project is ongoing in the Republic of Moldova, with the aim to develop a practical guide in line with requirements on export control systems of the World Customs Organization. The guide is intended for customs service employees, responsible government agencies, universities, academic institutions and relevant business communities involved in international trade of strategic goods. It will enhance the effectiveness of export control systems of dual-use items, combat the proliferation of weapons of mass destruction and related materials, equipment and technologies as well as assist students in training.

Ar. Buzdugan, A. Țurcanu

Li2B4O7 for Thermoluminescent Dosimetry: A New Life of an Old Material

The effect of doping conditions on the properties of Li2B4O7-based thermoluminescent materials is studied. It is shown that suppression of Mn clustering improves the linearity of the radiation dose response. Moreover, the order of doping is essential to achieve the formation of trapping and luminescence centers: simultaneous co-doping with Mg degrades the sensitivity of detectors by a factor of 10, while sequential Mg co-doping doesn’t diminish the sensitivity but decreases the dispersion of properties in the batch. The origin of the observed technological effects is discussed.

M. I. Danilkin, N. Yu. Vereschagina, A. S. Selyukov, D. I. Ozol

Backmatter

Additional information