[Dynamics of cognitive functions using the rehabilitation program of cognitive training]. / Dinamika kognitivnykh funktsii pri ispol'zovanii reabilitatsionnoi programmy kognitivnogo treninga.

OBJECTIVE: To study the efficiency of the neuropsychological rehabilitation of patients with mild cognitive impairments. MATERIAL AND METHODS: The study included 103 elderly people, aged 59 to 88 years, including 90 women and 13 men with subjective complaints of memory loss (ICD-10: F06.70; F06.71; F06.78; F06.79). Participants were divided into experimental group (n=43) and comparison group (n=42). The estimated impact was the rehabilitation program «The psychosocial therapy and neurocognitive rehabilitation of elderly patients with cognitive impairments¼, within which the principle of complex stimulation of various parameters of the cognitive sphere was used in rehabilitation work with patients in the experimental group in accordance with the «Memory Clinic¼ program. The study was conducted using randomized, equalized comparison groups, and the principle of «triple-blind¼ research. Non-parametric statistics (SPSS) methods were used to assess differences. RESULTS: A significant difference between the comparison and experimental groups has been identified, primarily in relation to high-level mental processes associated with the function of the third structural-functional block according to A.R. Luria. After the training, the number of correct answers significantly increased (t(42)=-2.67, p<0.001) in the experimental group, while in the comparison group the indicator did not change (t(41)=0.50, p=0.617). The number of false alarms in the experimental group decreased significantly (t(42)=2.13, p=0.039). CONCLUSION: The results confirm the leading role of these processes in the hierarchy of mental functions, which suggests that they should primarily be targets of rehabilitation interventions.

Changes in coastal ecosystems affected by overburden dumping from amber open-cut mining on the Sambia Peninsula (Baltic Sea).

The Sambia Peninsula (Kaliningrad region) is historically well known for its amber mining. The 2019 year was the last year of direct overburden disposal into the Baltic Sea as a part of technological amber mining process. The extremely high-suspended particulate matter concentrations during that disposal were recorded immediately after the discharge of significant volumes of pulp and reached 200 mg/L. The impact of pulp discharge had sequentially suppressed plankton communities development due to the high content of suspended solids and afterwards stimulated plankton development due to the glauconite infusion. Cladocera were the most sensitive group to the effects of suspended matter. According to the preliminary forecast, when the pulp discharge stops, the restoration of plankton communities may take from 1 to 2 seasons to 1 year for different groups. This is due to the timing of the removal of fine suspended particulate matter from sediments and the possibility of secondary entry during resuspension.

[Femoral nerve repair with autografts for proximal retroperitoneal damage (case report and literature review)]. / Autoplastika bedrennogo nerva pri ego proksimal'nom zabryushinnom povrezhdenii (klinicheskoe nablyudenie i obzor literatury).

Femoral nerve damage, especially in proximal retroperitoneal space, is rare. Therefore, surgical strategy is still unclear for these patients. Various specialists discuss repair with autografts or neurotization by the obturator nerve or its muscular branch. OBJECTIVE: To demonstrate the diagnostic algorithm for proximal femoral nerve injury and favorable outcomes after repair with long autografts. MATERIAL AND METHODS: We assessed movements and sensitivity using a five-point scale, as well as ultrasound, magnetic resonance imaging and electroneuromyography data in a patient with extended iatrogenic femoral nerve damage before and after repair with long autografts (10.5 cm). RESULTS AND DISCUSSION: The patient had complete femoral nerve interruption in proximal retroperitoneal space with 10-cm defect that required repair with five autografts from two sural nerves. Postoperative ultrasound and magnetic resonance imaging revealed signs of graft survival and no neuroma within the nerve suture lines. The first signs of motor recovery occurred after 10 months. After 14 months, strength of quadriceps femoris muscle comprised 4 points, and electroneuromyography confirmed re-innervation. CONCLUSION: Femoral nerve repair with autografts for complete proximal anatomical interruption can provide sufficient restoration of movements and sensitivity. Therefore, this surgical option should be preferred instead of neurotization. Ultrasound, MRI and ENMG are valuable to clarify the diagnosis and state of the autografts.

[Nanotechnologies in ophthalmology]. / Nanotekhnologii v oftal'mologii.

Application of new materials and methods in the diagnosis and treatment of eye diseases is one of the promising research areas in modern ophthalmology. Significant progress has been made in understanding the pathogenesis, diagnosis and treatment of eye diseases using nanotechnologies and nanomaterials. This paper presents the main achievements and results of original research on this issue. It has been shown that nanoparticles are able to overcome biological barriers, deliver drugs to the target site, and provide the required drug release rate. Modern nanotechnological approaches in tissue engineering are also being actively introduced into ophthalmology, making it possible to create nanoframeworks for growing three-dimensional cellular structures, including arrays of pigment epithelium cells and retinal ganglion cells for the treatment of retinal damage caused by degenerative diseases, injuries and infections.

Modeling the multifractal dynamics of COVID-19 pandemic.

To describe the COVID-19 pandemic, we propose to use a mathematical model of multifractal dynamics, which is alternative to other models and free of their shortcomings. It is based on the fractal properties of pandemics only and allows describing their time behavior using no hypotheses and assumptions about the structure of the disease process. The model is applied to describe the dynamics of the COVID-19 pandemic from day 1 to day 699 from the beginning of the pandemic. The calculated parameters of the model accurately determine the parameters of the trend and the large jump in daily diseases in this time interval. Within the framework of this model and finite-difference parametric nonlinear equations of the reduced SIR (Susceptible-Infected-Removed) model, the fractal dimensions of various segments of daily incidence in the world and variations in the main reproduction number of COVID-19 were calculated based on the data of COVID-19 world statistics.

Sample Size Calculation for Clinical Trials of Medical Decision Support Systems with Binary Outcome.

Currently, software products for use in medicine are actively developed. Among them, the dominant share belongs to clinical decision support systems (CDSS), which can be intelligent (based on mathematical models obtained by machine learning methods or other artificial intelligence technologies) or non-intelligent. For the state registration of CDSSs as software medical products, clinical trials are required, and the protocol of trial is developed jointly by the developer and an authorized medical organization. One of the mandatory components of the protocol is the calculation of the sample size. This article discusses the calculation of the sample size for the most common case, the binary outcome in diagnostic/screening and predictive systems. For diagnostic/screening models, cases of a non-comparative study, comparative study with testing of the superiority hypothesis, comparative study with testing of a hypothesis of non-inferiority in cross-sectional studies are considered. For predictive models, cases of randomized controlled trials of the complex intervention "prediction + prediction-dependent patient management" with testing of the hypothesis of superiority and non-inferiority are considered. It is emphasized that representativeness of the sample and other design components are no less important in clinical trials than sample size. They are even more important since systematic biases in clinical trials are primary, and even the most sophisticated statistical analysis cannot compensate for design defects. The reduction of clinical trials to external validation of models (i.e. evaluation of accuracy metrics on external data) seems completely unreasonable. It is recommended to perform clinical trials with the design adequate to the tasks, so that further clinical and economic analysis and comprehensive assessment of medical technologies are possible. The sample size calculation methods described in the article can potentially be applied to a wider range of medical devices.

[Treatment of neuropathy of inferior gluteal and pudendal nerves following periarticular synovial cyst of the hip joint. A case report and literature review]. / Rezul'tat lecheniya nevropatii nizhnego yagodichnogo i polovogo nervov, vyzvannoi periartikulyarnoi sinovial'noi kistoi tazobedrennogo sustava. Sluchai iz praktiki i obzor literatury.

The authors report a patient with neuropathy of inferior gluteal and pudendal nerves following periarticular synovial cyst of the hip joint. Effectiveness of treatment was analyzed. ENMG and MRI of pelvic soft tissues and hip joint were applied to confirm neuropathy of inferior gluteal and genital nerves. Periarticular synovial cyst of the hip joint followed by compression and ischemia of inferior gluteal and pudendal nerves was detected. In pre- and postoperative period, intensity of pain syndrome was assessed using visual-analogue scale. Neuropathic pain and quality of life were evaluated using the Leeds scale (LANSS) and NeuroQoL questionnaire, respectively. The patient underwent microsurgical neurolysis and decompression of inferior gluteal and pudendal nerves and resection of periarticular synovial cyst of the hip joint. Complete regression of pain syndrome and improvement in quality of life were observed after surgery. Compression of neurovascular structures with periarticular hip cysts followed by clinical and neurological disorders is an indication for microsurgical neurolysis and resection of cyst.

[Extravesical reimplantation of heavily-dilated ureters according to Bradi technique].

INTRODUCTION: Surgery of the ureterovesical anastomoses lesions in case of weakly-dilated ureters is well developed by the Cohen and Lich-Grgoire techniques. However, there are no generally accepted approaches for heavily-dilated ureters. The experience of creating ureterocystoneoanastomosis according to the Bradi technique (1975) for the first time in the literature is presented. MATERIALS AND METHODS: The authors modification of the Bradi technique was used in 12 patients of both sexes with a dilated ureters diameter of more than 10 mm. Two cases of refluxogenic and 10 cases of obstructive megaureter were operated on 2010-2019. The follow-up period was 1-10 years. All patients underwent resection of the ureter in width. RESULTS: No intraoperative complications were noted. One case of acute pyelonephritis with acute urinary retention was noted as postoperative complications. All patients showed a decrease in dilatation of the pyelocaliceal system and ureter according to multispiral computed tomography after 6 months of follow-up. Two patients had vesicoureteral reflux of the first degree. Glomerular filtration rates decreased in 41.7% of cases after 12 months of follow-up. No recurrence of urinary tract infection and stenosis of the anastomosis was detected for 1-10 years monitoring. CONCLUSION: The Bradi technique along with the Hodgsons ureter reconstruction provides superior results for heavily-dilated ureters in adults.

[Visceral debranching in hybrid surgery of thoracoabdominal aortic aneurysms]. / Vistseral'nyi debranching v gibridnoi khirurgii torakoabdominal'nykh anevrizm aorty.

Presented herein is a review of the literature dedicated to the method of visceral debranching, i. e., switching of the visceral and renal branches of the abdominal aorta to its intact portion, using synthetic vascular prostheses as the first stage of hybrid surgical treatment of thoracoabdominal aortic aneurysms prior to endovascular aortic aneurysm repair. This is accompanied and followed by describing the history of the problem, operative technique, results of studies, as well as the data from registries and meta-analyses. Also discussed are the main complications of the method and measures of their prevention. We conclude that hybrid surgery of the thoracoabdominal portion of the aorta is a promising method in a particular cohort of patients, especially those at high surgical risk of 'open' aortic surgery.

Elastic properties of superionic cubic silver sulfide ß-Ag2S.

Measurement of heat capacity of superionic silver sulfide (argentite ß-Ag2S) revealed that nanocrystalline argentite has a higher heat capacity than coarse-crystalline argentite. It is shown that the heat capacity of nanocrystalline substances includes an additional positive contribution caused by the limitation of the phonon spectrum on the part of low and high frequencies due to a small particle size. The estimation of this contribution on the basis of experimental differences in the heat capacities of nano- and coarse-crystalline argentite ß-Ag2S in the region of its existence, 470-850 K, made it possible to determine for the first time the velocities of propagation of longitudinal and transverse elastic vibrations cl and ct and elastic stiffness constants c11, c12 and c44. It is established that with a rise in temperature the elastic characteristics of argentite decrease. The anisotropy of elastic properties of cubic argentite was analyzed, and the crystal lattice directions corresponding to the largest and the least values of elastic moduli were determined. An increase of the temperature from 470 to 850 K leads to a small decrease of the elastic anisotropy of cubic ß-Ag2S argentite.

Disorder-order and order-order phase transformations in Ta5C4 phases predicted using the evolutionary algorithm and symmetry analysis.

A search for stable ordered phases in the nonstoichiometric cubic tantalum carbide TaC0.8 has been performed by use of the evolutionary algorithm and symmetry analysis. Four stable Ta5C4 superstructures with tetragonal, monoclinic, orthorhombic, and triclinic symmetry have been predicted for the first time. The DOS values of these Ta5C4 superstructures and stoichiometric TaC1.00 carbide have been calculated. All the tantalum carbide superstructures and stoichiometric TaC1.00 carbide have metal conductivity. The disorder-order phase transition channels TaCy → Ta5C4 associated with the formation of the considered model superstructures include superstructural vectors of non-Lifshitz stars {k1}, {k2}, and {k4}. The distribution functions of carbon atoms over the sites of the tetragonal, monoclinic, orthorhombic, and triclinic Ta5C4 superstructures have been calculated. For the first time, the physically permissible sequence of disorder-order and order-order phase transitions is established for the detected phases of the Ta5C4 family. Based on the formation enthalpy and the cohesion energy magnitudes, the triclinic Ta5C4 superstructure is the most favorable among all Ta5C4 phases predicted. The composition of the predicted Ta5C4 superstructures corresponds to TaC0.80 which possesses the highest melting temperature and hardness.

Low-temperature decomposition and segregation on a surface in carbide-containing solid solutions of the zirconium-niobium-carbon system and in related ternary systems.

The crystal structure and microstructure of pseudobinary (ZrC0.96)1-x(NbC0.97)x carbide solid solutions has been studied. It was found that monocrystalline grains of zirconium carbide are spontaneously isolated on the surface of diluted solid solutions of the pseudobinary system ZrCy-NbCy' containing less than 2.0 mol% of zirconium carbide. It is shown that the appearance of zirconium carbide is a consequence of the solid-phase decomposition of these solid solutions and anisotropy of elastic properties of monocrystalline ZrC carbide grains. The model of subregular solutions was used in the temperature interval from 300 to 3900 K to calculate and plot an equilibrium phase diagram of the ternary Zr-Nb-C system. It is shown that at temperatures above 1210 K in the Zr-Nb-C ternary system, nonstoichiometric carbides ZrCy and NbCy' have unlimited mutual solubility and form a continuous series of (ZrCy)1-x(NbCy')x solid solutions with 0.6 ≤ y ≤ 0.98, 0.7 ≤ y' ≤ 1.0, and 0 ≤ x ≤ 1.0. At temperatures below 1200 K, under equilibrium conditions, a discontinuity of the miscibility of the solid solutions ZrCy-NbCy' is observed and there appears a region of solid phase decomposition. The anisotropy of elastic properties of monocrystalline grains of ZrC was considered. It is predicted that solid-phase decomposition and surface segregation can be observed in such related carbide systems as HfCy-NbCy', HfCy-TaCy', ZrCy-TaCy', VCy-TaCy' and VCy-NbCy'.

[Possibilities of digital fluorography and other X-ray methods in the detection of carotid atherosclerosis]. / Vozmozhnosti tsifrovoi fliuorografii i drugikh luchevykh metodov v vyiavlenii ateroskleroza sonnykh arterii.

AIM: To evaluate possibilities of routine X-ray methods for the diagnosis of atherosclerosis of carotid arteries. MATERIAL AND METHODS: At the initial stage of the study, 468 X-ray radiograms of the cervical spine with the detailed description of soft tissues and projections of the neck vessels were studied. The next stage included evaluation of 'screening' abilities of digital fluorography of lungs (886 X-ray radiograms were analyzed). The last stage is a current pilot project aimed to introduce opportunistic screening of atherosclerosis of carotid arteries using X-ray and ultrasound examination of the thyroid gland taking into account disease history collected with help of a special questionnaire and clinical examination. RESULTS AND CONCLUSION: The study shows a high specificity of the shadows in the projections of the neck vessels as a sign of atherocalcinosis. During mass examinations these X-ray findings are useful to identify patients who need duplex scanning and other high-tech methods.

[Hibrid surgical treatment of an aortic arch aneurysm]. / Gibridnoe khirurgicheskoe lechenie anevrizmy dugi aorty.

Presented in the article is a clinical case report regarding hybrid surgical management of a saccular aneurysm of the aortic arch: simultaneous right-left-carotid-left-subclavian bypass grafting and endovascular isolation of the aneurysm. Taking into consideration the findings of multislice computed tomography-aortography (MSCT aortography) prior to surgery, the anatomical location of the aneurysm with the involvement of the ostium of the left subclavian artery, close location of the proximal branches of the aortic arch at an acute angle relative to each other required performing simultaneous debranching in order to enlarge the proximal zone of fixation of a stent graft at the level of the brachiocephalic trunk (BCT). The postoperative period proved uneventful, with as rapid rehabilitation as possible. From our own experience, with this one being not the first similar operation performed in the Centre, it may be supposed that carrying out simultaneous hybrid interventions in treatment of aneurysms of the aortic arch with the use of different variants of switching its branches may decrease the frequency of postoperative complications for patients of high surgical risk, reduce the length of hospital stay and, consequently, economic expenditures for treatment.

Semiconductor opening switch generator with a primary thyristor switch triggered in impact-ionization wave mode.

The results of the investigation involving a thyristor switch triggered in the impact ionization wave mode are presented. This switch is intended for operation as a primary switch in a nanosecond pulse generator with a semiconductor opening switch (SOS). The thyristor switch is based on commercial low-frequency tablet thyristors stacked in a joint assembly of up to 6 pieces connected in series. At a charging voltage of 2-12 kV and switching energy of up to 16 J, the switch operates with a discharge current of up to 8 kA, a current rise rate in the range from 14 to 54 kA/µs, and a switching efficiency of ∼0.9. It is shown that an increase in a voltage rise rate on thyristors at the triggering stage reduces energy loss in the thyristor switch during the current flow. The SOS pumping circuit contains one magnetic element-a pulse transformer, which simplifies the generator and increases its efficiency. The SOS generator has an output voltage of up to 300 kV and a peak power of up to 250 MW with a pulse duration of ∼50 ns. The thyristor switch in the generator operates at a voltage of 12 kV and provides current flow with the amplitude of up to 7.5 kA with a duration of ∼500 ns and a current rise rate of ∼54 kA/µs. The pulse repetition frequency of the generator is 1 kHz in the burst mode of operation.

[Neutrophils as a source of factors that increase the length of the inflammatory phase of wound healing in patients with type 2 diabetes mellitus]. / Neitrofily kak istochnik faktorov, uvelichivaiushchikh prodolzhitel'nost' fazy vospaleniia ranevogo protsessa u bol'nykh sakharnym diabetom 2-go tipa.

Oxidative stress and neutrophil activation leading to an increase in myeloperoxidase (MPO), elastase and neutrophil extracellular trap (NET) levels in blood are considered as pathogenic mechanisms responsible for the development of extremity damage in people with type 2 diabetes mellitus (T2DM). The aim of this study was to analyze the relationship between factors, associated with neutrophil activation, and the length of the initial phase of wound healing (the inflammatory phase) in T2DM patients. Patients were divided retrospectively into three groups depending on the damage extent: group 1 (wound on toe) < group 2 (wound on foot) < group 3 (wound on lower leg). Compared to the control group (healthy volunteers), T2DM patients at admission to hospital had significantly (p<0.05) increased levels of blood glucose and glycated hemoglobin (groups 1-3), ESR (groups 1 and 3), blood neutrophil count (groups 2 and 3), plasma MPO concentration (groups 1-3) and blood NET concentration (group 3) and decreased levels of plasma thiols (groups 1-3) and erythrocyte glutathione peroxidase activity (groups 2 and 3). The length of hospital stay after surgical procedures corresponded to the length of the inflammatory phase of the wound healing process and correlated with the number of blood neutrophils in patients before surgery (r=0.72, p<0.05). Leukocytic intoxication index depended on wound area (r=0.59, p<0.05), and it was significantly higher for groups 2 and 3 compared to the control group and group 1. The neutrophil count before surgery in T2DM patients with damage in the lower extremities correlated with the length of the inflammatory phase of wound healing. The correlation found can be attributed to an increase in extracellular MPO and NETs, which, in its turn, results from the activation and degranulation of neutrophils and netosis. Thus, the duration of the inflammatory phase of wound healing depends on specific aspects of systemic inflammation increasing oxidative/halogenative stress and intoxication.

A 30 GW subnanosecond solid-state pulsed power system based on generator with semiconductor opening switch and gyromagnetic nonlinear transmission lines.

This article describes a subnanosecond solid-state pulsed power system in which an input pulse from a generator with a semiconductor opening switch (generator) is amplified in power and is shortened in time by a two-stage magnetic compressor based on gyromagnetic nonlinear transmission lines. In this approach, the line of each stage operates as a magnetic compression line (MCL) which is realized when the duration of the input pulse is close to the period of oscillations generated by the line. The compression system contains two series connected lines MCL1 and MCL2 with a wave impedance of 40 Ω. The input pulse has a duration of 7 ns and an amplitude of 500 kV. After two compression stages, the pulse amplitude increases to 1.1 MV and the peak power increases from 6 to 30 GW, while the pulse duration transits into subnanosecond range (0.65 ns). In the burst mode, the system operates at a pulse repetition frequency up to 1 kHz.

[Staged treatment of a multilevel lesion of brachiocephalic arteries in combination with coronary and valvular pathology of the heart]. / Étapnoe lechenie mnogourovnevogo porazheniia brakhiotsefal'nykh arterii v sochetanii s koronarnoi i klapannoi patologiei serdtsa.

Prevention of neurological complications in cardiosurgical and reconstructive vascular surgery is one of the priority tasks of preserving ability to work and decreasing invalidization of patients in the postoperative period. Presented in the article is a clinical case report regarding multiple-stage treatment of a female patient with a combined aortic defect, coronary pathology, and a multilevel bilateral lesion of the brachiocephalic arteries. The first stage consisted in performing a hybrid operation, i. e., carotid endarterectomy from the right internal carotid artery and stenting of the ostium of the right common carotid artery (CCA). The second stage involved balloon angioplasty with stenting of the left CCA, and the third stage was prosthetic repair of the aortic valve by a mechanical prosthesis with simultaneous coronary artery bypass grafting. The woman was discharged in a satisfactory condition. Described in details is the technique of performing the hybrid vascular operation, followed by substantiating the stagewise nature of surgical interventions. The policy chosen demonstrates effective and safe correction of haemodynamically significant tandem stenoses of brachiocephalic arteries, without neurological complications during treatment of patients with cardiological pathology.

Escaping the Ashby limit for mechanical damping/stiffness trade-off using a constrained high internal friction interfacial layer.

The development of new materials with reduced noise and vibration levels is an active area of research due to concerns in various aspects of environmental noise pollution and its effects on health. Excessive vibrations also reduce the service live of the structures and limit the fields of their utilization. In oscillations, the viscoelastic moduli of a material are complex and it is their loss part - the product of the stiffness part and loss tangent - that is commonly viewed as a figure of merit in noise and vibration damping applications. The stiffness modulus and loss tangent are usually mutually exclusive properties so it is a technological challenge to develop materials that simultaneously combine high stiffness and high loss. Here we achieve this rare balance of properties by filling a solid polymer matrix with rigid inorganic spheres coated by a sub-micron layer of a viscoelastic material with a high level of internal friction. We demonstrate that this combination can be experimentally realised and that the analytically predicted behaviour is closely reproduced, thereby escaping the often termed 'Ashby' limit for mechanical stiffness/damping trade-off and offering a new route for manufacturing advanced composite structures with markedly reduced noise and vibration levels.

Correction: High-temperature X-ray diffraction and thermal expansion of nanocrystalline and coarse-crystalline acanthite α-Ag2S and argentite ß-Ag2S.

Correction for 'High-temperature X-ray diffraction and thermal expansion of nanocrystalline and coarse-crystalline acanthite α-Ag2S and argentite ß-Ag2S' by S. I. Sadovnikov et al., Phys. Chem. Chem. Phys., 2016, 18, 4617-4626.