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Copolymers based on vinylidene fluoride are potential materials for ferroelectric memory elements. The trend in studies showing that a decrease in the degree of crystallinity can lead to an unexpected increase in the electric breakdown field is noted. An analysis of the literature data reveals that in fluorine-containing ferroelectric polymers, when using a bipolar triangular field, the hysteresis loop has an unclosed shape, with each subsequent loop being accompanied by a decrease in the dielectric response. In this work, the effect of the structure of self-polarized films of copolymers of vinylidene fluoride with tetrafluoroethylene and hexafluoropropylene on breakdown processes was studied. The structure of the polymer films was monitored using infrared spectroscopy (IR) and X-ray diffraction. Kelvin probe force microscopy (KPFM) was applied to characterize the local electrical properties of the polymers. For the films of the first copolymer, which crystallize in the polar β-phase, asymmetry in the dielectric response was observed at fields greater than the coercive field. For the films of the copolymers of vinylidene fluoride with hexafluoropropylene, which crystallize predominantly in the nonpolar α-phase, polarization switching processes have also been observed, but at lower electric fields. The noted phenomena will help to identify the influence of the structure of ferroelectric polymers on their electrical properties.

Aim. To assess the safety and efficacy of percutaneous transluminal balloon angioplasty with stenting for renal graft artery stenosis. Material and methods. From June 2018 to December 2022, 344 kidney transplants from a deceased donor were performed at the surgical clinic of City Clinical Hospital n.a. S.P. Botkin. The study group consisted of 220 men (63.9%) and 124 women (36.1%). The mean age was 46.46±11.74 (19–73) years. With a mean follow-up period of 20.05 (1-54) months, stenosis of the renal graft artery was diagnosed in 4 patients (1.16%). The mean time from transplantation to the diagnosis of stenosis was 4 (1–9) months. In addition, we diagnosed the development of this complication in 4 kidney transplant recipients operated in other centers. The mean time from transplantation to the diagnosis of stenosis in these patients was 103.25 (12–221) months. Thus, we have the experience in the treatment of renal transplant arterial strictures in 8 recipients: 4 men (50%) and 4 women (50%). The mean age was 48.25±11.97 (27–60) years. Stenosis was manifested by renal graft dysfunction with a progressive increase in urea and creatinine in 6 patients (75%), by arterial hypertension in 2 patients (25%). The mean, level of creatinine at the time of diagnosing stenosis was 290.75 (157–494) µmol/L, glomerular filtration rate was 22.87±12.19 (8–41) ml/min/1.73m2 . Results. In the early postoperative period, 1 complication was recorded in the form of pulsating hematoma of the common femoral artery, which required surgical intervention (complication class IIIA according to Clavien-Dindo). The mean hospital postoperative bed-days made 5.22 (4-8). The mean follow-up time was 22.75±7.4 (14–33) months. All recipients were alive throughout the whole follow-up period. In 7 of 8 recipients (87.5%), the graft was functioning, in 1 patient a progressive graft dysfunction was noted, for which chronic hemodialysis was started. Mean creatinine in recipients with a functioning graft was 156.71±33.4 (123–200) µmol/L; mean glomerular filtration rate was 41.57 ml/min/1.73m2 . Conclusions. Percutaneous transluminal balloon angioplasty with stenting is a safe and effective minimally invasive technique and should be considered as the operation of choice in the development of renal graft artery stenosis.

The lecture is intended for training specialists in higher educational establishments according to the Federal state standard «Robotics for military and special purposes» and also for training operators of robotic complexes (facilities) for military purposes in training centers and military units. The lecture addresses two study questions: 1) Retrospective analysis of radiation accidents and their consequences. 2) Analysis of the use of robotic technology and robotics systems for elimination the consequences of radiation accidents. Conclusion: The material presented in the lecture is aimed at expanding the knowledge of those who are trained in the history of radiation accidents (disasters), as well as in the use of robotic technology and robotic systems for eliminating the consequences of such accidents. The analysis of the use of robotics in conditions of an increased radiation background, given in the lecture, will make it possible to form the necessary competencies of specialists of the NBC protection troops in order to effectively perform their tasks as intended.

The anniversary collection of essays compiled and edited by Nataliia Polosina, Anna Shvets and Artem Zubov pays tribute to Tatiana Venediktova — Doctor of Philology, professor of American studies, founder and chair of the Department of Discourse and Communication studies at the Philological Faculty of Lomonosov Moscow University, member of the LoA editorial board. Her colleagues, friends and students contributed to the collection. Pavel Balditsyn, Julia Idlis, Mikhail Makeev, Grigoriy Kruzhkov recall the experience of cooperating with Tatiana Venediktova and working on major joint projects like the History of Literature of the United States (1997–2013) and editions of American poets in the academic book series “Literturnye Pamiatniki”. They focus on her work as a researcher, teacher, translator, publisher, academic administrator. The essays by Andrey Astvatsaturov and Sergei Zenkin commemorate the 20th anniversary of her seminal book Conversation in American: Discourse of Bargaining in the American Literary Tradition (2003). They reflect upon the impact the book had in the Russian academia back in the 2000s and its relevance for the humanities scholarship in the 2020s. The anniversary collection is a symbol of gratitude, love and respect towards Tatiana Venediktova, a recognition of her valuable contribution to the American studies and humanities in general in Russia and beyond.

The human genome is pervasively transcribed and produces a wide variety of long non-coding RNAs (lncRNAs), constituting the majority of transcripts across human cell types. Some specific nuclear lncRNAs have been shown to be important regulatory components acting locally. As RNA-chromatin interaction and Hi-C chromatin conformation data showed that chromatin interactions of nuclear lncRNAs are determined by the local chromatin 3D conformation, we used Hi-C data to identify potential target genes of lncRNAs. RNA-protein interaction data suggested that nuclear lncRNAs act as scaffolds to recruit regulatory proteins to target promoters and enhancers. Nuclear lncRNAs may therefore play a role in directing regulatory factors to locations spatially close to the lncRNA gene. We provide the analysis results through an interactive visualization web portal at https://fantom.gsc.riken.jp/zenbu/reports/#F6_3D_lncRNA.

The publication relates to the problems of digitalization of building materials science. The relevance of developing a digital model of concrete for solving optimization problems of design and synthesis of its structure, clarifying methods for calculating building structures, and improving the technology of their production is shown. The evolution of information modeling of concrete is analyzed in the context of the stages of development of system-building materials science and technology. A review of the main modern methods of computer modeling of concrete structure in domestic and foreign scientific research is provided. It is noted that these methods do not take into account the complexity of the structure of concrete. In the article, concrete is presented as a conglomerate composite with a hierarchically organized structure with dimensions from 10-10 to 10-1 m. It has a minimum of 5-6 scale levels and three types of substructure design. Substructures differ in their scale, genesis and mechanics of manifestation of properties. The first type of substructure is characteristic of the macro-, meso- and micro-scale levels. It is accepted in the form of a two-component “construction” of a spatially continuous matrix and discrete inclusions deterministically and stochastically distributed in it. The second type refers to the submicro-, ultra-micro- and nanoscale levels. It is believed to be in the form of a “microscale spatial structure” of new formations of a cementing substance from consolidated individual crystalline differences. The third type corresponds to the atomic-molecular structure of new formations of the cementing substance. The characteristics of each type of substructure are given according to: the scale of the components; features of formation; mechanics of properties manifestation; design criteria; means of synthesis. An assumption is made about the specificity of modeling each of the three types of concrete substructures and their integration into a single digital model. The task is to develop an information platform for such a model. The platform should include: a theoretical knowledge base; empirical data base; database of analytical, numerical and statistical models; algorithms for designing and synthesizing structures; optimization criteria and boundary conditions; terms of reference for computer modeling of concrete.

Sequence variants in gene regulatory regions alter gene expression and contribute to phenotypes of individual cells and the whole organism, including disease susceptibility and progression. Single-nucleotide variants in enhancers or promoters may affect gene transcription by altering transcription factor binding sites. Differential transcription factor binding in heterozygous genomic loci provides a natural source of information on such regulatory variants. We present a novel approach to call the allele-specific transcription factor binding events at single-nucleotide variants in ChIP-Seq data, taking into account the joint contribution of aneuploidy and local copy number variation, that is estimated directly from variant calls. We have conducted a meta-analysis of more than 7 thousand ChIP-Seq experiments and assembled the database of allele-specific binding events listing more than half a million entries at nearly 270 thousand single-nucleotide polymorphisms for several hundred human transcription factors and cell types. These polymorphisms are enriched for associations with phenotypes of medical relevance and often overlap eQTLs, making candidates for causality by linking variants with molecular mechanisms. Specifically, there is a special class of switching sites, where different transcription factors preferably bind alternative alleles, thus revealing allele-specific rewiring of molecular circuitry.

Aim. To evaluate the efficacy of catheter ablation (CA) of atrial fibrillation (AF) in patients with left ventricular systolic dysfunction and the effect of the procedure on the course of chronic heart failure (CHF) compared with the use of antiarrhythmic therapy (AAT).Materials and methods. The study included patients (n=80) with left ventricular ejection fraction (LVEF) less than 50% and AF, who were divided into 2 groups: the first group (n=40) underwent CA, the second group included patients on AAT. At baseline and after 6 months of follow-up, transthoracic echocardiography, determination of NT-proBNP concentration, 6-minute walk test and The Minnesota Living With Heart Failure Questionnaire were performed.Results. After 6 months of follow-up, the absence of documented AF paroxysms was observed in 80% in the CA group versus 45% in the AAT group (p=0,001). A significant increase in LV EF was revealed in both groups, however, in CA group it was more significant (57% [50,5; 60] in the CA group versus 46% [40; 50] in the AAT group (p=0,0001)). There was a decrease in the left ventricle ESD and the left atrial size and volume in the CA group, while in the AAT group the dynamics of these parameters did not change within six months (p=0.0001). An improvement in the clinical course of CHF was observed in both groups: the level of NT-proBNP was 196,6 [116,5; 327,1] pg/ml and 540.5 [382,8; 861,2] pg/ml (0,0001), the 6-minute walk distance increased to 470 m [400; 500] and 368 [330; 400] m (p=0,0001), respectively, the improvement of the functional class (1,15±0,67 and 2,05±0,55 (p=0,0001)) and the quality of life (p=0,0001) were observed.Conclusion. CA is an effective method for patients with AF and CHF. The use of CA in patients with CHF promotes reverse remodeling, a decrease in the level of NT-proBNP, as well as an improvement in the quality of life and an increase in exercise tolerance.

Neural crest cells are highly multipotent stem cells, but it remains unclear how their fate restriction to specific fates occurs. Here, the authors show in zebrafish that broad multipotency is retained even after migration, suggesting that fate restriction occurs directly, but dynamically.

Paleosols are frequently used to recreate past climates. In the forest-steppe zone of the Russian Plain (Lipetsk region, Russia), Early Iron and Middle Ages defensive ramparts' buried soils were discovered. The parent material and similar topographic situations served as the foundation for the comparison of buried and surface soils. Following the dynamics of the landscape from 2500 years ago to the present is possible according to detailed chrono-sequences of soils positioned in similar relief positions and in the same parent material. In this article, an analysis of 8 soils buried at various times is described. The data add to the original research and include detailed morphological descriptions that conform to international standards. Physico-chemical analysis includes determination of pH, organic and carbonate carbon, exchange cations, macro- and microelements. Numerous analytical techniques can be used to investigate issues including the genesis and deterioration of the mollic horizon, the influence of human activity on the production and preservation of Chernozems, and the degree and rate of changes in soil features driven on by climatic changes.

Increasing prospective phytochemical investigations and biological activities on Pueraria lobata and Trifolium pratense flowers exhibited their nutritional (food industry) pharmaceutical (anticancer, anti-inflammatory, anti-microbial, etc.) potentials. Previous studies paid great attention to the screening of isoflavones profile from phytochemicals. This study, in contrast, aimed at identifying the flavonoids from Pueraria lobata flowers or kudzu flower (KF) and Trifolium pratense flowers or red clover (RC) flowers and determining their cytotoxic activities on normal; (HEK-293) and cancer cell lines; human glioblastoma (A-172), osteosarcoma (HOS), embryonic rhabdomyosarcoma (Rd), lung carcinoma (A-549) and liver carcinoma (HepG2). The phytochemical screening using a high-performance liquid chromatography-diode array detector coupled with quadrupole time-of-flight mass spectrometry (HPLC-DAD-Q-TOF/MS) showed that 15 flavonoids, including isoflavones, flavones, flavonols, and flavanones, were identified in KF and 8 flavonoids, including isoflavones and flavonols, were found in RC. Nevertheless, the majority of flavonoid chemical constituents in KF or RC were found to be isoflavones (66.6%) and (62.5%), respectively. HPLC-DAD analysis following eco-friendly extraction of phytochemicals showed that KF contains mainly daidzein and genistein, while RC contains primarily formononetin and biochanin A. Cytotoxic activities evaluated according to IC50 values exhibited the most pronounced dose-dependent antiproliferative effect of KF and RC extracts were against HOS and Rd cancer cell lines, respectively. Accordingly, the morphological observation carried out using acridine orange/ethidium bromide and Giemsa stains revealed apoptotic activities and cell death in HOS and Rd cell lines when subjected to KF or RC extracts. Cytotoxic activities and apoptotic changes were pronounced among all cancer cell lines except for the control cells (HEK-293). Additionally, various polyphenols and flavonoids were identified and quantified in KF and RC extracts and exhibited potent radical scavenging activities. Overall, this study suggests that KF and RC could be valuable edible sources of flavonoids. The comprehensive flavonoid profiles for KF and RC may explain their remarkable biological activities and contribution to inducing antioxidant and cytotoxic activities against cancer cell lines.

Sustainable development is the core of China’s ecological strategy which includes climate problems as its part. It means that industrial development remains an important component of ecological policy, besides, the government undertakes gigantic projects which change the nature, for example a massive transfer of water from the southern rivers to the northern regions. Also, sustainable development is understood in China as one of the means to reduce poverty and has a complex social content. Energy transformation in China has accelerated during the 12th-13th five year plans (2011-2020), however coal remains the main source of energy for the world largest manufacturing power taking more than 56 percent of total consumption. Major national goals include now “creating of beautiful China” and some current plans to accelerate energy transformation are viewed in the article as well as a short history of the power sector of China’s economy in this century. Important part of the study is devoted to the analysis of “green” financial services, which are developing in modern China with growing speed. Despite tempting, the plans for speedy reforms and structural changes in energy sector run across major obstacles. They include efficiency and cost problems, the giant scope of the energy sector. Another set of obstacles comes from deep divide on climate problems and sustainable development in general between the developed and developing countries.

Aim. To evaluate the effect of continuous intravenous infusion of alprostadil solution on the dynamics of the peripheral resistance to arterial blood flow and renal graft function in the early postoperative period.Material and methods. From June 2018 to May 2022, 278 kidney transplants from a deceased donor were performed at the City Clinical Hospital n.a. S.P. Botkin. In 179 recipients operated from June 2018 to May 2021, we evaluated the significance of the intraoperatively determined resistance index of blood flow in the segmental arteries of the renal graft as a predictor of the development of its delayed function. The study of the effect of alprostadil included 32 patients divided into 2 groups comparable in patient age, gender, body mass index. The resistance index in both groups was more than 0.85. In the second group patients received a continuous intravenous infusion of alprostadil solution in the first 3 days after surgery.Results. Retrospectively we found that in patients with a high resistance index (more than 0.85), the risk of developing delayed graft function was 6.9 times higher, that was statistically significant (p=0.001). In the alprostadil group, a delayed graft function developed in 5 of 18 patients (27.8%), compared with the control group, where delayed graft function developed in 9 of 14 (64.3%) patients, however, without reaching the level of statistical significance (p=0.072). The median time to normalization of graft function in group II was 4 (interquartile range: 3–4) days, while in group I it was 7 (interquartile range: 5–8) days (p=0.05). The median hospital length of stay in the alprostadil group was significantly lower than in the control group and amounted to 13 (interquartile range: 8–15) versus 17 (interquartile range: 15–19) days (p=0.032).Conclusion. The use of continuous intravenous infusion of alprostadil solution after kidney transplantation in patients with a high intraoperative resistance index can safely and effectively lead to a decrease in resistance index to normal rates, accelerate the recovery of graft function and significantly reduce the incidence of delayed graft function. However, further research is needed.

Using a wide range of modern mineralogical and physicochemical methods, a representative collection of human bones from seven burial grounds of the Vychegda Permians of the 11th–14th centuries was studied. The microstructure of bones, their chemical and normative-mineral composition, the content of microelements, the nanoporosity of the organo-mineral composite, the composition and properties of bioanatite and bone collagen were analyzed. Fundamental differences in the properties of raw and so-called calcified bones are determined. Based on isotope data on bioapatite and collagen of raw bones, the climatic conditions for the existence of the Vychegda Permians and their diets were reconstructed.

Objective. The aim of the work is to study the use of nanofluids as heat carriers to increase the efficiency of heat removal in energy facilities. To solve this problem, materials of domestic and foreign scientific articles, conferences and dissertations on the subject of nanofluids were analyzed. Numerous scientific publications, including those cited in the international databases Web of Science and Scopus, indicate that the topic of nanofluids is in the focus of modern science. However, despite a rather long period of fluid research, not all issues of this topic are sufficiently well covered and systematized, which opens up great opportunities for further research in this direction.Method. When achieving this goal, the areas of possible application of fluids, the mechanism of their synthesis, the features of their operation are considered, the advantages as a liquid coolant are indicated, and the disadvantages that prevent their widespread use are identified. Particular attention is paid to such issues as: synthesis of standardized nanofluids; ensuring their stable properties; the use of surfactants; increasing the pressure drop inside heat exchangers during operation of this coolant.Result. To eliminate the main drawback in the form of agglomeration of nanoparticles in the base fluid, it is proposed to use the oscillatory circulation of the coolant, which will also further intensify heat exchange from forced turbulence of the fluid.Conclusion. The results obtained can be used to improve the efficiency of heat and mass transfer devices with liquid coolant and systems based on them, as well as to reduce the weight and size parameters of such devices.

А clinical case of a young patient with recurrent ischemic strokes is presented. The problems of diagnostic embolic strokes are discussed. We set out the algorithm for identifying patients, in whom patent foramen ovale is the most probable cause of embolic stroke. Detailed consideration of imaging diagnostic methods possibility is included. Hypothesis of probable source of cardioembolism from patent foramen ovale is presented. Recommendations for the secondary prevention of recurrent ischemic stroke, associated with patent foramen ovale, are provided. We also considered the issues of antithrombotic treatment.

Aim. To determine statistically significant risk factors for delayed renal graft function. To assess the impact of delayed kidney graft function on the development of other complications, graft and recipient survival.Material and methods. In 237 consecutive kidney transplant recipients (from June 2018 to December 2021), we assessed its function in the early postoperative period. Delayed function was considered to be the need for hemodialysis in the first week after surgery. Among the donor factors, the type of donor, age, body mass index, the presence of vasopressor support, the time the donor was in intensive care, and the maximum level of creatinine during the follow-up were evaluated. Recipient risk factors include age, gender, body mass index, presence/absence and amount of urine, presence of preformed anti-HLA antibodies and/or repeated kidney transplantation, number of mismatches for six HLA antigens, number of mismatches for HLA-DR, presence and type of renal replacement therapy, etiology of end stage kidney disease. Among the perioperative risk factors are the duration of cold preservation, the time of second warm ischemia, the volume of intraoperative blood loss, the intraoperatively determined renal arterial resistive index of the renal graft, and the maximum concentration of tacrolimus in the first 4 days after kidney transplantation. After that the relationship between the presence of delayed kidney graft function and the development of early postoperative complications was assessed and its effect on the long-term survival of grafts and recipients was analyzed.Results. Out of 237 cases, 9 showed no function of the transplanted kidney, and therefore the grafts were removed. The incidence of delayed renal graft function was 24.5% (58/237). According to the results of a univariate analysis, a statistically significant relationship with the development of delayed kidney graft function had donor body mass index (p=0.019), male gender of the recipient (p=0.048), recipient body mass index (p=0.038), amount of urine (p=0.003), anuria (p=0.002), presence of preformed antibodies (p=0.025), repeated transplantation (p=0.002), time of second warm ischemia (p=0.036), intraoperative renal arterial resistive index (p=0.004) and maximum tacrolimus concentration in the first 4 days (p=0.022). In the multivariate model, donor body mass index >30 kg/m2 and peak tacrolimus concentration >23 ng/mL in the first 4 days were statistically significant (p=0.018 and p=0.025, respectively). A trend towards statistical significance was noted in the presence of oligoanuria before kidney transplantation (p=0.066) and resistance index >0.75 after surgery (p=0.056). One-year renal transplant survival in the absence and presence of delayed kidney graft function was 92.4% and 87.7%, two-year survival was 89.4% and 76.1%, respectively. The effect of delayed kidney graft function on graft survival was statistically significant (p=0.01), while overall recipient survival did not differ between the groups.Conclusion. During the univariate analysis, we identified 9 statistically significant factors, of which at least 3 are potentially modifiable. In the multivariate model, the most significant modifiable risk factor was an increased concentration of tacrolimus, which prompted the authors to reconsider the existing immunosuppressive protocol at the City Clinical Hospital n.a. S.P. Botkin. We consider the search for modifiable statistically significant risk factors for patients, their analysis and implementation of preventive measures to be an important task for each kidney transplant center.

Abstract Computational tools provide a unique opportunity to study and design optimal materials by enhancing our ability to comprehend the connections between their atomistic structure and functional properties. However, designing materials with tailored functionalities is complicated due to the necessity to integrate various computational-chemistry software (not necessarily compatible with one another), the heterogeneous nature of the generated data, and the need to explore vast chemical and parameter spaces. The latter is especially important to avoid bias in scattered data points-based models and derive statistical trends only accessible by systematic datasets. Here, we introduce a robust high-throughput multi-scale computational infrastructure coined MISPR (Materials Informatics for Structure–Property Relationships) that seamlessly integrates classical molecular dynamics (MD) simulations with density functional theory (DFT). By enabling high-performance data analytics and coupling between different methods and scales, MISPR addresses critical challenges arising from the needs of automated workflow management and data provenance recording. The major features of MISPR include automated DFT and MD simulations, error handling, derivation of molecular and ensemble properties, and creation of output databases that organize results from individual calculations to enable reproducibility and transparency. In this work, we describe fully automated DFT workflows implemented in MISPR to compute various properties such as nuclear magnetic resonance chemical shift, binding energy, bond dissociation energy, and redox potential with support for multiple methods such as electron transfer and proton-coupled electron transfer reactions. The infrastructure also enables the characterization of large-scale ensemble properties by providing MD workflows that calculate a wide range of structural and dynamical properties in liquid solutions. MISPR employs the methodologies of materials informatics to facilitate understanding and prediction of phenomenological structure–property relationships, which are crucial to designing novel optimal materials for numerous scientific applications and engineering technologies.

Two series of the bismuth tantalate pyrochlore samples, codoped with Mg,Mn and Zn,Mn, were synthesized via solid-phase reaction. It was established that the Bi2Mg(Zn)xMn1−xTa2O9.5−Δ (x = 0.3; 0.5; 0.7) samples contain the main phase of cubic pyrochlore (sp. gr. Fd-3m) and an admixture of triclinic BiTaO4 (sp. gr. P-1). In both sets, the amount of BiTaO4 is proportional to the amount of manganese doping, however, zinc-containing samples have a higher level of impurities than magnesium-containing ones. The unit cell parameter of the Zn,Mn codoped bismuth tantalate phase increases with an increasing content of zinc ions in the samples from 10.4895(5) (x = 0.3) to 10.5325(5) Å (x = 0.7). The unit cell parameter of Mg,Mn codoped bismuth tantalate pyrochlores increases uniformly with an increasing index x(Mg) from 10.4970(8) at x = 0.3 to 10.5248(8) Å at x = 0.7, according to the Vegard rule. The NEXAFS and XPS data showed that the ions were found to have oxidation states of Bi(+3), Ta(+5), Zn(+2) and Mg(+2). In the Ta 4f XPS spectrum of both series of samples, a low energy shift of the absorption band characteristic of tantalum ions with an effective charge of (+5-δ) was observed. The XPS spectra of Bi4f7/2 and Bi4f5/2 also show a shift of bands towards lower energies which is attributed to the presence of some low-charge ions of transition elements in the bismuth position. The NEXAFS spectroscopy data showed that manganese ions in both series of samples have predominantly 2+ and 3+ oxidation states. XPS data indicate that in zinc-containing preparations the proportion of oxidized manganese ions is higher than in magnesium-containing ones.

The impact of spacer layers’ thickness on the resonant-tunneling diode’s (RTD) current-voltage characteristic and operational parameters of the RTD-based subharmonic mixer was studied during the described research using the software package developed by authors to simulate the RTD’s functional parameters while mixer’s parameters were simulated using existing microelectronic CAD. The research has revealed that the main impact on both RTD’s I-V characteristic’s shape and operational parameters of the studied subharmonic mixers is made by the emitter spacer layer’s thickness while the collector spacer’s thickness’ variation is insignificant in both cases. Such, it is shown that by varying the emitter spacer’s thickness from a single monolayer to twice its nominal value it’s possible to alter the RTD’s peak current from 0,28 to 1,92 of its nominal value. spacer layer’s thickness deviation of ±1 monolayer has a noticeable effect on the studied mixer’s operational parameters, especially on its dynamic range.

The article considers ways to preserve populations of protected plant species on the example of a natural regional wood park "Sludah woods" in Nizhny Novgorod. The population fitness is assessed, including environmental conditions, population density and ontogenetic percentage. The environmental conditions according to the Ellenberg scores are assessed. The conservation and repatriation of the protected species are considered. Recommendations are supposed to use the agrotechnical measures to conserve rare herbaceous species under conditions of urban environment.