Search

Introduction. The prevalence of chronic rhinosinusitis, an increase in the resistance of pathogenic microorganisms, growing numbers of patients with allergic reactions to antibiotics necessitates the use of topical antibacterial therapy or the nasal cavity and paranasal sinuses, which are accessible for local remedies.Aim. Efficacy and tolerability of topical antibacterial drug hydroxymethylquinoxalindioxide in the treatment of chronic rhinosinusitis exacerbation has been investigated in our study.Materials and methods. An open non-invasive observational study of efficacy and tolerability of irrigation therapy with hydroxymethylquinoxalindioxide in 50 adult patients with exacerbation of chronic rhinosinusitis has been conducted at the Department of Otorhinolaryngology, Pavlov State Medical University (Saint Petersburg). The patients were randomized into 2 groups. In the first group, patients were treated with 40 ml of 0.25% hydroxymethylquinoxalindioxide solution nasal irrigation b.i.d. for 7 days, in the second – the same amount of normal saline was used. Duration and severity of symptoms, dynamics of nasal endoscopic picture, and the results of bacteriological study were evaluated before and after the treatment. Safety was assessed according to the data of complete blood cell count, mucociliary transport time and the incidence of adverse events.Results and discussion. In the hydroxymethylquinoxalindioxide group, there was a statistically significant improvement in the mucociliary transport time by the end of treatment from 19.1 ± 5.08 minutes to 15.2 ± 1.2 minutes (p = 0.002) compared to the normal saline group. According to the results of bacteriological study, eradication of the pathogen in the hydroxymethylquinoxalindioxide group was achieved in 85% (n = 21), comparing to only 17% (n = 4) of cases in the control group.Conclusion. Irrigation therapy with 0.25% hydroxymethylquinoxaline dioxide is more effective than saline flush solution. The drug can be recommended for irrigation therapy in adults with chronic rhinosinusitis exacerbation.

Recurrent respiratory papillomatosis (RP) is one of the most challenging benign tumors of the upper and lower respiratory tract. Dissemination of the tumor process and damage to the lung tissue not only increase the likelihood of malignancy, but also complicate the choice of treatment tactics, largely limit the surgical options, and necessitate a multidisciplinary approach.Methods. The enrolled patients with RP have been treated (n = 190) in the Federal State Budgetary Educational Institution of Higher Education “Academician I.P.Pavlov First St. Petersburg State Medical University”, Ministry of Healthcare of Russian Federation, from 2000 to the present. Changes in the lung tissue were detected in 5 (2.6%) patients (2 men and 3 women) with aggressive course of the disease.Results. The clinical characteristics of patients and the outcomes of lung damage in RP are presented. Four patients had malignant transformation of the tumor into verrucous carcinoma of the upper third of the trachea with invasion into the soft tissues of the neck (n = 1) or malignant degeneration of the lesion in the lung parenchyma (n = 3).Conclusion. The presented rare observations suggest polymorphism of clinical and radiological symptoms of papillomatous damage to the tracheobronchial system and lungs.

Aim of the study was to compare the cutting and coagulation properties of 1.56 and 1.94 μm fiber lasers with those of a 0.98 μm semiconductor laser.Materials and methods. A comparative study of the biological effects of 1.56 and 1.94 µm lasers and a 0.98 µm semiconductor laser used in a constant, continuous mode was carried out. The cutting properties of the lasers were evaluated on the chicken muscle tissue samples by the width and depth of the ablation zone formed via a linear laser incision at a speed of 2 mm/s, while the coagulation properties were assessed by the width of the lateral coagulation zone. The zones were measured using a surgical microscope and a calibration slide. For statistical analysis, power values of 3, 5, 7, 9, and 11 W were chosen for each laser wavelength.Results. Analysis of the findings confirmed that laser wavelength had a statistically significant effect on the linear dependence between incision parameters and laser power. It was found that the 1.56 μm fiber laser (water absorption) had a greater coagulation ability but a comparable cutting ability compared with the 0.98 μm laser (hemoglobin absorption). When used in the power mode of 7W or higher, the 1.94 µm laser provided superior cutting performance compared with the 0.98 µm semiconductor laser at the same exposure power. Elevating the power in any of the lasers primarily increased the width of the ablation zone, and to a lesser extent – the crater depth and the width of the lateral coagulation zone. Therefore, in comparison with the 0.98 μm semiconductor laser, higher radiation power in the 1.56 and 1.94 μm lasers mainly influences their cutting properties, expanding the width and depth of the ablation zone, and has a smaller effect on their coagulation ability.Conclusion. The findings of the study showed that the 1.56 and 1.94 μm fiber lasers have better coagulation properties in comparison with the 0.98 μm semiconductor laser. was statistically proven that all incision characteristics (width of the lateral coagulation zone, depth and width of the ablation zone) for the 1.56, 1.94, and 0.98 μm lasers depend on the power of laser radiation. The 1.94 µm laser is superior to the 0.98 µm laser in its cutting properties.

The research featured the effect of the dominant cognitive style on the creativity of college students. The research objective was to study the dynamic transformations of the content characteristics of creativity in college students with different cognitive styles. The article introduces various approaches to the concepts of cognitive style and creativity in foreign and domestic psychology. A set of experiments revealed the necessity to take into account the dominant cognitive style as a creativity determiner and proved the effect of cognitive style on creativity. The authors studied the dynamics of creativity in students, based on their field dependence / independence and integrity / differentiality. The field-dependent students appeared to be more involved in the academic information al environment. They were unable to change their attitudes and opinions, even in conditions of directional influence during the psychological training. The field-independent student showed better creativity after the psychological training as they strived to develop their own attitude to all incoming information. The participants with predominating differentiality were more creative, while their differential state vector depended on their ability to satisfy their need to detail the information they perceived and produced.

We have studied the electronic and electromagnetic properties of synthesized Ni0.5Zn0.5Fe2O4 nickel-zinc ferrite nanopowders. The Ni0.5Zn0.5Fe2O4 materials prepared by a pyrochemical nitrate–urea process and a sol–gel nitrate–citrate process have been shown to differ in microstructural, electronic, and electromagnetic characteristics. In the frequency range 1–7 GHz, the Ni0.5Zn0.5Fe2O4 ferrite prepared by the pyrochemical nitrate–urea process, with an average nanoparticle size of 33 nm, has a higher magnetic permeability, dielectric permittivity, and magnetic loss tangent than does the Ni0.5Zn0.5Fe2O4 material with an average nanoparticle size of 46 nm, prepared by the sol–gel nitrate–citrate process.

Local resistive switching in a contact between the probe of an atomic force microscope (AFM) and ZrO2(Y) films (including with a Ta2O5 sublayer) on conducting substrates has been studied. Switching has been initiated by triangular voltage pulses on which an rf sine-wave signal was imposed. The dependence of the difference between currents through the AFM probe in low- and high-ohmic states of dielectric films on the frequency of the rf sine-wave signal exhibits maxima at characteristic frequencies corresponding to hops of O2– ions between oxygen vacancies in ZrO2(Y) and Ta2O5 at 300 K. This effect is related to the resonance activation of O2– ion migration over oxygen vacancies by an external rf electric field.

В статье представлены результаты эмпирического исследования временных характеристик образа мира (компоненты семантического слоя) представителей коренных малочисленных народов Севера юношеского возраста. В целях экспериментального исследования применялась трехуровневая модель образа мира, эмпирическое описание специфики образа мира представителей коренных этносов юношеского возраста с использованием указанной модели проведено впервые.

The article presents an interesting case of rare inflammatory myofibroblastic tumor of the larynx, associated with long-term chronic laryngitis and recurrent leukoplakia of the vocal fold. Patient P., 74 years old, was urgently tracheotomized due to rapidly progressive tumor stenosis of larynx in ENT-hospital on duty. A week later our clinic successfully performed laser microsurgical excision of the tumor with simultaneous decanulation. Such approach was possible due to intraoperative express histological examination, which showed no signs of malignancy. Following immunohistochemical analysis made it possible to diagnose a rare inflammatory myofibroblastic tumor. Over 10 years the patient P. suffered from chronic laryngitis and recurrent leukoplakia of the vocal folds, which was operated 3 times in our clinic. Since the role of chronic inflammation is discussed in the genesis of myofibroblastic tumor and laryngeal leukoplakia of the larynx, we prescribed a prolonged 2-months course of azithromycin after the excision of the tumor. This treatment option rarely used in chronic laryngitis, resulted in substantial improvement of voice quality, stable remission of chronic laryngitis and the absence of recurrence of leukoplakia and inflammatory myofibroblastic tumor in patient P. during the next 2-year observatin. A retrospective histological examination of the histological preparation of leukoplakia removed from patient P. in 2012, showed the presence of a biofilm of coccal flora and few bacilli covering the keratosic masses. This finding, together with obvious clinic effect of prolonged antibacterial treatment, gives the reason to suggest a significant role of bacterial inflammation in the genesis of larynx leukoplakia.

Local resistive switching by complex nonstationary signals in zirconium-dioxide-stabilized films on conducting substrates has been studied by atomic-force microscopy with a conducting probe. Film resistance was switched by triangular voltage pulses on which a high-frequency sinusoidal signal was superimposed. It is found that the ratio of currents through the junction between the probe and film surface in high-resistance and low-resistance states increases after the superposition of a sinusoidal signal (as compared to switching by simple triangular pulses). An increase in the temporal stability of the current strength in these states was also found when switching with a sinusoidal signal. This effect is associated with resonant activation of oxygen ion migration over vacancies in an external ac electric field.

Mine-explosive trauma is one of the most serious types of combat lesion and injuries in peacetime. We report a patient with mine-explosive trauma of the lower limbs followed by injury of the vascular bundle. Well-coordinated work of a multidisciplinary team of specialists at all stages of treatment is presented. The management was effective to save patient's life, avoid amputation and restore lower limb function.К числу наиболее тяжелых видов боевой травмы и травм мирного времени относятся минно-взрывные повреждения. Описан клинический случай минно-взрывной травмы ног с повреждением сосудистого пучка, демонстрирующий слаженную работу мультидисциплинарной бригады специалистов на всех этапах лечения, которая позволила не только сохранить жизнь пациентке, но и в последующем, избежав ампутации, восстановить функцию нижних конечностей.

Research focused on the problem of developing digital adaptive equalizer in the frequency band of wideband HF communication to overcome the negative effect of nonlinear phase dispersion. Developed methods, algorithms and software are supported by the SDR technology and were implemented with the use of the USRP N210 platform. They use state-of-the-art approaches in digital signal processing, including those elaborated by the authors. Verification of methods, algorithms, and software for adaptive equalization was carried out in full-scale experiments on LFMCW sounding over the Cyprus-to-yoshkar-Ola propagation path of length of 2600 km. Besides, the specific objective of the research was studying equalization efficiency in megahertz-bandwidth channels the single-mode (1F mode) propagation band.

Paper presents a new method of studying phase-frequency response (PFR) of a wideband HF channel. There are presented experimental PFR measured with the use of SDR ionosonde of Volga state university of technology. They allowed to estimate spreading (group delay dispersion) of wideband channel impulse responses due to dispersion. With the use of the proposed approach to the estimation of the phase measurement errors we obtained the experimental values of that errors.

Paper presents a technique for calculating the integrated power delay profile of a wideband HF radio channel. Studies focused on the ionospheric radio links. The specific objective of the research were the dependences of the areas of a priori uncertainty of the average delay and the delay window on the path length and geophysical factors. An algorithm for maintaining synchronization of terminals of the SDR chirp ionosonde.

The time dynamics of the spatial distribution of electrons locally injected from the probe of an atomic force microscope into thin (less than 10 nm) ZrO2(Y) films with embedded Au nanoparticles on Si substrates is studied via Kelvin probe force microscopy. The profiles of the film surface potential induced by the injection of a countable number (several tens) of electrons into Au nanoparticles, as a function of the time elapsed after injection, are measured and analyzed.

The resonant activation of resistance switching (RS) of a memristor based on an yttria stabilized zirconia (YSZ) film with embedded Au nanoparticles (NPs) was investigated. The switching was made by triangular pulses with high frequency (HF) sinusoid added. A non-monotonous dependence a ratio of the electric current through the memristor in the low resistive state to the current in the high resistive one on the HF sinusoid frequency was found. The effect was explained by a finite electron tunneling time between the Pt electrode and Au NPs. This conclusion was supported by measuring a dependence of HF memristor capacitance on the probing signal frequency.

Bleeding after tonsillectomy is a serious complication that requires emergency care. The tactic of treatment for bleeding after tonsillectomy depends on the intensity of bleeding and predisposing factors. The paper presents an analysis of the causes of secondary bleeding in patients after tonsillectomy.

Low-mass galaxies are known to have played the crucial role in the hydrogen reionization in the Universe. In this paper we investigate the contribution of soft x-ray radiation (E ~ 0.1–1 keV) from dwarf galaxies to hydrogen ionization during the initial reionization stages. The only possible sources of this radiation in the process of star formation in dwarf galaxies during the epochs preceding the hydrogen reionization epoch are hot intermediate-mass stars (M ~ 5–8 M⊙) that entered the asymptotic giant branch (AGB) stage and massive x-ray binaries. We analyze the evolution of the intergalactic gas in the neighborhood of a dwarf galaxy with a total mass of 6 × 108M⊙ formed at the redshift of z ~ 15 and having constant star-formation rate of 0.01–0.1 M⊙ yr−1 over a starburst with a duration of up to 100 Myr. We show that the radiation from AGB stars heats intergalactic gas to above 100 K and ensures its ionization xe ≳ 0.03 within about 4–10 kpc from the galaxy in the case of a star-formation rate of star formation 0.03–0.1 M⊙ yr−1, and that after the end of the starburst this region remains quasi-stationary over the following 200–300 Myr, i.e., until z ~ 7.5. Formation of x-ray binaries form in dwarf galaxies at z ~ 15 results in a 2–3 and 5–6 times greater size of the ionized and heated region compared to the case where ionization is produced by AGB stars exclusively, if computed with the “x-ray luminosity–star-formation rate” dependence (LX ~ fXSFR) factor fX = 0.1 and fX ~ 1, respectively. For fX ≲ 0.03 the effect of x-ray binaries is smaller that that of AGB star population. Lyα emission, heating, and ionization of the intergalactic gas in the neighborhood of dwarf galaxies result in the excitation of the 21 cm HI line. We found that during the period of the starburst end at z ~11.5–12.5 the brightness temperature in the neighborhood of galaxies is 15–25 mK and the region where the brightness temperature remains close to its maximum has a size of about 12–30 kpc. Hence the epoch of the starburst end is most favorable for 21 cm HI line observations of dwarf galaxies, because at that time the size of the region of maximum brightness temperature is the greatest over the entire evolution of the dwarf galaxy. In the case of the sizes corresponding to almost 0.’1 for z ~ 12 regions with maximum emission can be detected with the Square Kilometre Array, which is currently under construction.

Black holes growing during Eddington accretion emit a large number of ultraviolet and x-ray photons which can influence the ionization and thermal state of the surrounding intergalactic gas before the onset of the hydrogen reionization epoch in the universe. This radiation heats the gas beyond the temperature of the relict radiation (cosmic microwave background CMB) TCMB (z) to a red shift z ~ 8 –12 within 0.1-3 Mpc of a black hole with initial mass ~300 M⨀ formed at z ~ 20-50 and growing with radiation efficiency e ~ 0.15 – 0.075. The size of the gas regions in which the degree of ionization of hydrogen is higher than the residual value after recombination, i.e., greater than 10-4, approaches the same levels. More substantial heating and ionization of the gas takes place in a smaller volume. In the vicinity of 30-300 kpc, for the same black hole parameters, it is heated to above 104 K or almost an order of magnitude greater than around a black hole with almost constant mass. The radiative flux from growing black holes is sufficient for complete (above 99%) production of ionized hydrogen and doubly ionized helium within 3-10 kpc of the parent minihalo. The recombination time for hydrogen in the ionization zones surrounding the black holes exceeds the local age of the universe for z ≲ 10. These zones, which occupy several kiloparsecs, can become seeds for the next reionization of the universe. It turns out that extended regions with sizes of hundreds of kiloparsecs where radiation from growing black holes substantially changes the evolution of the intergalactic gas will radiate in the 21 cm line of atomic hydrogen, since the gas in these zones essentially remains neutral at a temperature exceeding that of the CMB.

In this paper, we address the question of how a central intermediate-mass black hole (IMBH) in a globular cluster (GC) affects dynamics, core collapse, and formation of the binary population. It is shown that the central IMBH forms a binary system that affects dynamics of stars in the cluster significantly. The presence of an intermediate-mass black hole with mass ≥ 1.0-1.7%of the total stellar mass in the cluster inhibits the formation of binary stars population.

Research has been carried out to study the use of a new feed product prepared on the basis of ginger oil cake and feed concentrate from vegetable raw materials “Sarepta” in feeding poultry meat cross Ross-308. These feed products allow to increase the live weight, the digestibility of nutrients in the diet and improve meat productivity. The results of weighing of broiler chickens showed superiority in live weight of the II experimental group - 2612.76 g, where protein-vitamin-mineral concentrate BVMC (S) was used as an additive in compound feed in the amount of 7.5, 10 and 12%, respectively, during the start, growth and finish. The live weight of the I experimental group was 2512.54 g, where protein-vitamin-mineral concentrate BVMC (R) was used as an additive, the dosages were similar to the II experimental group. The weight of the control group chickens was 2370.80 g, respectively. The conducted experience showed that the chickens of the experimental groups exceeded the control analogues in the digestibility of dry matter by 0.27-0.57%, crude protein - by 0.45-1.48%, crude fiber - by 0.7-2.53%, crude fat - by 0.94-2.29%. The results of anatomical cutting of the carcass showed the superiority of the experimental groups.

The paper presents the main results of the experiment on the use of high-protein concentrate “Gorlinka” in the diets of dairy cows and laying hens on their productive qualities. It was found that in terms of the main indicators of nutritional value (protein, fat, nitrogen-free extractives, ash elements), as well as in terms of amino acid composition and mineral substances, the studied concentrate surpasses the traditionally used in feeding farm animals and birds, oil cake and meal from sunflower seeds. The results of studies have shown that the groups of animals that received protein concentrate with the diet were in the lead. The use of protein concentrate “Gorlinka” in the feeding of dairy cows and laying hens increased the average daily milk yields of cows by 5.47-7.12%. There were also positive changes in the mass fraction of protein in milk by 0.03-0.04%, in dry matter by 0.04-0.09%, in the number of eggs laid by laying hens by 216-822 pieces, in the average egg weight by 0.77-1.66 g. Thus, the use of protein concentrate “Gorlinka” in feeding dairy cows and laying hens had a positive effect on the quality of the products (milk and edible eggs), while economic indicators improved.

We report on the application of Contact Scanning Capacitance Microscopy (CSCM) to trace the growth of an individual Ni filament in a ZrO2(Y) film on a Ni sublayer (together with a conductive Atomic Force Microscope probe composing a nanometer-sized virtual memristor). An increasing of the filament length in the course of electro-forming results in an increasing of the capacitance between the probe and the sample, which can be detected by CSCM technique. This way, the filament growth can be monitored in real time in situ.

Deep stellar photometry of one of the most distant Galactic globular clusters, Palomar 3, based on frames taken with the VLT in Johnson-Cousins broadband V and Ifilters is presented, together with medium-resolution stellar spectroscopy in the central region of the cluster obtained with the CARELEC spectrograph of the Observatoire de Haute Provence and measurements of the Lick spectral indices for the integrated spectrum. Computations of the orbital parameters of Palomar 3 and nine Galactic globular clusters with similar metallicities and ages are also presented. The orbital parameters, age, metallicity, and distance of Palomar 3 are estimated. The interstellar absorption is consistent with and supplements values from the literature. The need to obtain more accurate data on the proper motions, ages, and chemical compositions of the cluster stars to elucidate the origin of this globular cluster is emphasized., Comment: 20 pages, 8 tables, 7 figures

Paper presents the findings of the research into the influence of polarization interference on the frequency and impulse responses of a radio channel. Numerical experiments were carried out to analyze variations of the crossing point of magnetoionic components, the region of their high interference. Variations of polarization coherent bandwidth were studied for different mid-band frequencies of a radio channel depending on the geophysical factors.

Paper is addressed to the problem of taking into account the space-time variability of daily variations of coherent bandwidths for the transionospheric radio channel of satellite communications. We applied an analytical approach to the development of a mathematical model for computing coherent bandwidth in the transionospheric radio channel. An algorithm and a system that integrates hardware and relevant software for plotting regional digital maps of coherent bandwidths with the use of experimental data on the total electron content of the ionosphere were developed. There are presented experimental data on diurnal variations of coherent bandwidths over the Republic of Mari EI and Tatarstan.

Paper focuses on the problem of training an adaptive system to correct for frequency dispersion in ionospheric radio channels with a 1-MHz bandwidth. The characteristics of a radio channel were measured in the full-scale experiments over the mid-latitude propagation path Cyprus -Yoshkar-Ola. There are presented the data on variations of amplitude-frequency response of a HF radio channel with a 1-MHz bandwidth from the single-mode propagation band. An algorithm for estimating an impulse response of a wideband channel is presented.

A technique for estimating the amplitude of variations in the total electron content of the ionosphere is shown. The variations of the total electron content of the ionosphere (TEC) in different geomagnetic conditions are analyzed and a comparative analysis of TEC variations for different seasons of 2015 over the territory of eight settlements of the Southern Federal District is carried out using satellite data of GPS / Glonass systems. The analysis of how the variations in the total electron content of the ionosphere vary depending on the latitude of the reference stations.

Local resistive switching (RS) in ZrO2(Y) films on conductive substrates has been studied using Conductive Atomic Force Microscopy (CAFM). Switching was performed by triangle voltage pulses with superimposed a high-frequency (HF) sinusoidal signal applied to the contact of the CAFM probe to the ZrO2(Y) film (together constituting a nanometer-sized virtual memristor). Earlier, the enhancement of the RS performance has been observed when the HF signal was superimposed onto the switching pulses. The effect was attributed to the resonant activation of the migration of oxygen ions via oxygen vacancies by an external alternating electric field. In the present study, this assumption was confirmed by measuring the frequency dependence of the difference between the probe currents in the low-resistance and high-resistance states with a maximum at about 5 kHz. This frequency corresponds to the characteristic one of the jumps of oxygen ions onto adjacent oxygen vacancies in ZrO2(Y) at 300 K. The experimental results were compared with the results of simulation based on the Chua model of an ideal memristor.

The article presents a preliminary analysis of the application of the new non-invasive method of treatment of degenerative-dystrophic diseases of large joints. The aim of the study was to examine the results of the cutaneous insertion of a nitroglycerin solution at a concentration of 2.5 mg/ml with degenerative diseases of knee and hip joint. Materials and methods. In 9 patients studied results: physical, x-ray studies; testing scales: the Oxford Knee Score, KOOS-WOMAC, Lisholm, Leken, Harris; blood gases; pulse oximetry; capillaroscopy. Results. All patients satisfied with treatment, significant pain re-duction, increase range of motion, rejection of the use of means of additional supports, as evidenced by the data evaluation scales. Indicators of blood gas composition, the data of pulse oximetry, capillaroscopy showing improvements in tissue circulation. Conclusions. Cutaneous application of nitroglycerin in the us used concentration improves blood circulation and, as a consequence, the metabolism in the affected joint that can slow the progression of the disease. Ease of use will allow you to apply a method of treating patients not only in hospital but on an outpatient basis.

The article discusses the themes of ethnic stereotypes and lifestyle of indigenous peoples of the North and the non-indigenous peoples. The indigenous peoples identify with their ethnic group, positive evaluation of their perceptions of themselves prevail. The indigenous peoples believe that the representatives of other ethnic groups assess them less positively, and in fact, the representatives of non-indigenous peoples evaluate them even worse than they suppose. The students from the number of indigenous peoples consider as the most important parameters for the evaluation of their lifestyle (factors of evaluations): “unattractiveness - attractiveness”, “peacefulness - hostility”, “melancholy - sanguine”. The students from the number of non-indigenous people consider the most important parameters for the evaluation of their lifestyle: “well-being - ill-being”, “hostility - peacefulness”, “sanguine - melancholy”. The testees of both samples evaluate their lifestyle more positively at the conscious, reflexive level (universals), than at the unconscious, uncontrolled level (implicit factor structure of evaluations). The testees of both samples evaluated their lifestyle completely differently at the unconscious, non-regulated level (factorial structure of evaluations), indigenous people have more introverted, non-indigenous people have more extroverted evaluations.

The problem concerning new software-defined radio technology is investigated as applied to the successive sounding of HF ionospheric communication radio channels. The algorithm for quadrature processing of chirp signals subjected to elementwise compression in the frequency domain is developed. It is established that a channel scattering function and a delay power profile are related to a compressed-signal spectrum and their basic parameters. Data on the key characteristic of HF communications modems are presented. The efficiencies of different modems are estimated using the experimental data on channel parameters. It is demonstrated that the aforementioned technology can be used to estimate not only HF communication channel parameters from the pass band of a radio line but also select the optimal one and, furthermore, makes it possible to combine communications and radio sounding systems in the single device.

This paper discusses novel approaches to the numerical integration of the coupled nonlinear Schr&ouml, dinger equations system for few-mode wave propagation. The wave propagation assumes the propagation of up to nine modes of light in an optical fiber. In this case, the light propagation is described by the non-linear coupled Schr&ouml, dinger equation system, where propagation of each mode is described by own Schr&ouml, dinger equation with other modes&rsquo, interactions. In this case, the coupled nonlinear Schr&ouml, dinger equation system (CNSES) solving becomes increasingly complex, because each mode affects the propagation of other modes. The suggested solution is based on the direct numerical integration approach, which is based on a finite-difference integration scheme. The well-known explicit finite-difference integration scheme approach fails due to the non-stability of the computing scheme. Owing to this, here we use the combined explicit/implicit finite-difference integration scheme, which is based on the implicit Crank&ndash, Nicolson finite-difference scheme. It ensures the stability of the computing scheme. Moreover, this approach allows separating the whole equation system on the independent equation system for each wave mode at each integration step. Additionally, the algorithm of numerical solution refining at each step and the integration method with automatic integration step selection are used. The suggested approach has a higher performance (resolution)&mdash, up to three times or more in comparison with the split-step Fourier method&mdash, since there is no need to produce direct and inverse Fourier transforms at each integration step. The key advantage of the developed approach is the calculation of any number of modes propagated in the fiber.

Measuring parameters of the scattering function of near vertical incidence skywave (NVIS) radio links employed for data transmission is topical and fosters better understanding signal propagation as well as developing state-of-the-art cognitive radio systems. In this regard, the paper presents the findings of the research into the application of a noise-like phase-shift keying (PSK) signal for vertical sounding of NVIS radio links. There are presented the developed algorithms for processing the PSK signal to measure the scattering function and its parameters (signal-to-noise ratio, delay spread and Doppler spread) for multiple communication channels in the high frequency (HF) band. To carry out experiments on measuring scattering function of radio channels with bandwidth of 24 kHz and different mid-band frequencies, we employed developed ionosonde based on the universal software radio peripherals (USRP) platform.

The objective of the present work was to elucidate the specific features of the clinical picture of allergic rhinitis in the pregnant women. The study included 156 pregnant women presenting with the persisting form of the disease and 63 patients having its intermitting form. The character of the endoscopic manifestations of rhinitis, chronic tonsillitis, and gastroesophageal reflux was evaluated with the use of a scoring system. The progressive development of the clinical symptoms of allergic rhinitis during pregnancy related neither to the contacts with allergens nor to the discontinuation of pharmacotherapy was documented in 33 and 23% of the patients presenting with the persistent and intermitting forms of the disease, respectively. The symptoms of rhinitis in the pregnant women may be influenced by the presence of gastroesophageal reflux (the endoscopic evidence of this condition was documented in 84.6% of the examined patients with persisting form of the disease and in 40.3% of those having intermitting form) and chronic tonsillitis (purulent contents in the palatine tonsil lacunes were found in 46.8 and 40.3% of the women presenting with the persisting and intermitting forms of allergic rhinitis respectively). In 42% of the cases, the cause behind the negative dynamics or the absence of any dynamics during the treatment of allergic rhinitis was the withdrawal of the prescribed pharmacotherapy by the patients themselves. This observation gives evidence of the importance of explaining to the pregnant women suffering from allergic rhinitis the necessity of compliance with the prescribed treatment modalities in order to reduce the probability of development of complications of this condition.Цель исследования - выявить особенности течения аллергического ринита у беременных. Группу исследования составили беременные женщины с аллергическим ринитом: 156 - с персистирующей и 62 - с интермиттирующей формой заболевания. Степень эндоскопических проявлений ринита, хронического тонзиллита и гастроэзофагеального рефлюкса оценивалась в баллах. Нарастание симптомов аллергического ринита во время беременности, не связанное с усилением контакта с аллергенами или отменой лекарственной терапии, установлено у 33% больных персистирующей и 23% больных интермиттирующей формой ринита. Влияние на симптомы ринита у беременных могут оказывать гастроэзофагеальный рефлюкс (эндоскопические признаки выявлены у 84,6% женщин с персистирующей и у 77,4% с интермиттирующей формой ринита), хронический тонзиллит (гнойное содержимое в лакунах небных миндалин выявлено в 46,8 и 40,3% случаев соответственно). В 42% случаев причиной отрицательной динамики или ее отсутствия на фоне лечения аллергического ринита являлась самостоятельная отмена беременными назначенной лекарственной терапии, что подчеркивает актуальность разъяснения пациенткам необходимости лечения с целью уменьшения вероятности осложнений.

The paper is addressed to the problem of compensation for the energy losses caused by the second-order phase frequency dispersion in a transionospheric radio channel. To minimize losses, it is crucial to measure the characteristics of wideband channels and correct them for dispersion with the use of data gathered by GNSS/GPS navigation systems. Correction is reasonable when the processing gain from the correction exceeds a required threshold. The developed method allows to estimate the potential processing gain from the correction for dispersion distortions in transionospheric radio channels.

We carried out experimental studies of parameters of HF modems operating over mid-latitude and subpolar paths of the length of 2.6 and 2.4 Mm, for periods of weak geomagnetic disturbances (

The paper is addressed to the problem of supporting NVIS communication by means of vertical-incidence BPSK ionosonde which uses single antenna. Ionosonde was developed by means of SDR technology with the use of USRP platform. Signal processing algorithms aimed at measuring channel scattering function and estimating channel parameters are presented. They allow to measure signal-to-noise ratio, delay spread and Doppler spread in a channel. We have proposed an algorithm aimed at supporting NVIS communication by choosing an appropriate communication channel or a certain modem which ensures reliable communication over a required channel.

The paper presents the findings of the research into the effects of material dispersion in an optical fiber link. The general framework of normal and anomalous dispersion of the second and third orders were formulated by means of a principle of equivalence. The approach to the problem is based on a method of transforming a frequency response of an equivalent liner system into its impulse response with the use of a dispersion characteristic. This approach was used to thoroughly consider the effects of chirping, soliton (stable) propagation and collapse of solitons.