Search

We present a comparative analysis of various methods for solving the problem of determining the spectral characteristics of mathematical models of control systems (decision support systems). It is suggested that a better fit between a method and the model is possible if we consider the specifics of the object or technological process. Based on the model experiments, we made a conclusion about the advantages of using the power method and the Khilenko method, when the range of variation of the rates of calculated variables is unknown or can change significantly with the operating modes of an object (technological process) change as well as in critical situations and the need to “work off” them by the control system.

Objectives This paper sets out to provide a theoretical substantiation of the placement of external fire-prevention water supply sources when designing unique construction objects, for which standard requirements of fire safety cannot be applied. Problematic situations arising during the design of unique construction objects, which relate to the provision of the required level of fireextinguishing substances supply, are described.Method A model constructed on the basis of graph theory is presented for the preliminary calculation of the location of external fire-fighting water supply sources that takes the equipment of fire-rescue units into account. The utility of developing a universal mathematical model for the preliminary definition of arrangement parameters of sources of external fire-prevention water supply when designing construction objects is substantiated.Results Examples of preliminary calculation of the number of external fire-fighting water supply sources are given considering the shape of the building perimeter. Additional factors determining the distances from external fire-fighting water supply sources to the projected objects are given.Conclusion A conclusion regarding the adequacy of the proposed model is formulated and directions for future research indicated that allows the applicability of the model to be specified for the calculation of the projected objects, which differ in terms of dimensions given in the plan by above-normative characteristics.

For assessing the core critical heat flux ratio in VVER-type nuclear reactors, the lattice computation code TIGRSP (steady-state thermal and hydraulic analysis of parameters in fuel rod bundles) is used. Despite the fact that quite a large amount of verification studies has been accomplished and that the code has passed the certification procedure, work on improving the code capabilities is still being continued. One of the modern tendencies is the wide-scale involvement of CFD codes for studying local parameters in fuel assemblies (FAs). Along with comparison with experimental data, it is advisable to carry out cross verification of lattice codes with the results of 3D thermal-hydraulic computations for conditions for which experimental data are either lacking or limited for some or other reasons. This article considers thermal-hydraulic processes during coolant flow in a 19-rod assembly with parameters close to the nominal conditions in the FAs of a VVER-1000 reactor. The 3D model is verified with respect to empirical formulas and experimental data. Based on the results of test and verification computations, we determined the mesh and turbulence model parameters using the ANSYS CFX code by means of which it is possible to obtain reliable results in estimating the hydraulic characteristics of FAs fitted with spacer grids, heat transfer in the single-phase region, and coolant flow distribution over the FA cross section. The CFD computation of coolant flow for the 19-rod assembly is carried out, and the coolant mass velocity and temperature in different sections over the length and corresponding cells of the TIGRSP code are calculated. The TIGRSP code has been verified against experimental data and taking into account the CFD simulation of the 19-rod FA, and a software module for graphically visualizing the lattice code output results has been developed. The presented data can be used for verification of thermal-hydraulic codes and in elaborating the design of FAs for VVER-type reactors.

Carotid paragangliomas (CPGLs) are rare neuroendocrine tumors of the head and neck. "Germline" and somatic mutations in a number of genes were shown to be associated with the development of CPGLs; however, molecular mechanisms of the tumor pathogenesis have not been fully understood. In the work, we have used whole exome sequencing data of 52 CPGLs obtained earlier. Using MutSigCV, the search for genes with high mutation rate was performed. Thirty four genes (MADCAM1, SARM1, ZFPM1, CTDSP2, DSPP, POTED, ANP32B, FRG2B, BAGE3, CCDC89, ACOT2, KRTAP10-1, ATXN1, GXYLT1, MUC2, AQP7, TMPRSS13, KRTAP4-3, PRR21, PSPH, PLBD1, ZNF595, IGSF3, PRR16, FAM157A, KCNJ12, HYDIN, IGFBP2, KIAA1671, DISC1, MUC6, XKR3, HRNR, and MUC4) potentially associated with the CPGL initiation and progression were revealed. The involvement of these genes in the pathogenesis of CPGLs was first shown, and possible mechanisms of their participation in that were discussed.

Carotid paragangliomas (CPGLs) are rare neuroendocrine tumors often associated with mutations in SDHx genes. The immunohistochemistry of succinate dehydrogenase (SDH) subunits has been considered a useful instrument for the prediction of SDHx mutations in paragangliomas/pheochromocytomas. We compared the mutation status of SDHx genes with the immunohistochemical (IHC) staining of SDH subunits in CPGLs. To identify pathogenic/likely pathogenic variants in SDHx genes, exome sequencing data analysis among 42 CPGL patients was performed. IHC staining of SDH subunits was carried out for all CPGLs studied. We encountered SDHx variants in 38% (16/42) of the cases in SDHx genes. IHC showed negative (5/15) or weak diffuse (10/15) SDHB staining in most tumors with variants in any of SDHx (94%, 15/16). In SDHA-mutated CPGL, SDHA expression was completely absent and weak diffuse SDHB staining was detected. Positive immunoreactivity for all SDH subunits was found in one case with a variant in SDHD. Notably, CPGL samples without variants in SDHx also demonstrated negative (2/11) or weak diffuse (9/11) SDHB staining (42%, 11/26). Obtained results indicate that SDH immunohistochemistry does not fully reflect the presence of mutations in the genes, diagnostic effectiveness of this method was 71%. However, given the high sensitivity of SDHB immunohistochemistry, it could be used for initial identifications of patients potentially carrying SDHx mutations for recommendation of genetic testing.

The article presents method of modeling the phenomenon of secondary frost heaving. The authors describe also the conditions under which the model is applicable according to the assumptions used in the process of its creating. The model is rigorously mathematically formulated. A method of solving the corresponding boundary problem is given. A computation of a numerical example was made. The graph characterizing the process of ice layers formation is given. One layer is formed under some conditions and two layers are formed under other conditions. It depends on the temperature of the pipe. In the case of given numeric example the authors recom-mend how to prevent frost heaving. The recommendation is of general nature and may be used in other cases.

Background Carotid body tumor (CBT) is a form of head and neck paragangliomas (HNPGLs) arising at the bifurcation of carotid arteries. Paragangliomas are commonly associated with germline and somatic mutations involving at least one of more than thirty causative genes. However, the specific functionality of a number of these genes involved in the formation of paragangliomas has not yet been fully investigated. Methods Exome library preparation was carried out using Nextera® Rapid Capture Exome Kit (Illumina, USA). Sequencing was performed on NextSeq 500 System (Illumina). Results Exome analysis of 52 CBTs revealed potential driver mutations (PDMs) in 21 genes: ARNT, BAP1, BRAF, BRCA1, BRCA2, CDKN2A, CSDE1, FGFR3, IDH1, KIF1B, KMT2D, MEN1, RET, SDHA, SDHB, SDHC, SDHD, SETD2, TP53BP1, TP53BP2, and TP53I13. In many samples, more than one PDM was identified. There are also 41% of samples in which we did not identify any PDM; in these cases, the formation of CBT was probably caused by the cumulative effect of several not highly pathogenic mutations. Estimation of average mutation load demonstrated 6–8 mutations per megabase (Mb). Genes with the highest mutation rate were identified. Conclusions Exome analysis of 52 CBTs for the first time revealed the average mutation load for these tumors and also identified potential driver mutations as well as their frequencies and co-occurrence with the other PDMs. Electronic supplementary material The online version of this article (10.1186/s12920-018-0327-0) contains supplementary material, which is available to authorized users.

// Svetlana O. Zhikrivetskaya 1,* , Anastasiya V. Snezhkina 1,* , Andrew R. Zaretsky 2 , Boris Y. Alekseev 3 , Anatoly V. Pokrovsky 4 , Alexander L. Golovyuk 4 , Nataliya V. Melnikova 1 , Oleg A. Stepanov 1,3 , Dmitry V. Kalinin 4 , Alexey A. Moskalev 1 , George S. Krasnov 1 , Alexey A. Dmitriev 1 and Anna V. Kudryavtseva 1,3 1 Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia 2 M.M. Shemyakin - Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia 3 National Medical Research Radiological Center, Ministry of Health of the Russian Federation, Moscow, Russia 4 A.V. Vishnevsky Institute of Surgery, Moscow, Russia * These authors have contributed equally to this work Correspondence to: Anna V. Kudryavtseva, email: // Keywords : paragangliomas, pheochromocytomas, molecular markers, germline and somatic mutations, signaling pathways Received : August 02, 2016 Accepted : January 23, 2017 Published : February 08, 2017 Abstract Paragangliomas/pheochromocytomas comprise rare tumors that arise from the extra-adrenal paraganglia, with an incidence of about 2 to 8 per million people each year. Approximately 40% of cases are due to genetic mutations in at least one out of more than 30 causative genes. About 25–30% of pheochromocytomas/paragangliomas develop under the conditions of a hereditary tumor syndrome a third of which are caused by mutations in the VHL gene. Together, the gene mutations in this disorder have implicated multiple processes including signaling pathways, translation initiation, hypoxia regulation, protein synthesis, differentiation, survival, proliferation, and cell growth. The present review contemplates the mutations associated with the development of pheochromocytomas/paragangliomas and their potential to serve as specific markers of these tumors and their progression. These data will improve our understanding of the pathogenesis of these tumors and likely reveal certain features that may be useful for early diagnostics, malignancy prognostics, and the determination of new targets for disease therapeutics.

When one solves engineering problems related to the cooling of fuel assemblies (FAs) in a spent fuel storage pool (SFSP) and the assessment of nuclear safety of FA storage in an SFSP in the initial event of loss of SFSP cooling, it is essential to determine the coolant density and, consequently, steam volume fractions φ in bundles of fuel elements at a pressure of 0.1–0.5 MPa. Such formulas for calculating φ that remain valid in a wide range of operating parameters and geometric shapes of channels and take the conditions of loss of SFSP cooling into account are currently almost lacking. The results of systematization and analysis of the available formulas for φ are reported in the present study. The calculated values were compared with the experimental data obtained in the process of simulating the conditions of FA cooling in an SFSP in the event of loss of its cooling. Six formulas for calculating the steam volume fraction, which were used in this comparison, were chosen from a total of 11 considered relations. As a result, the formulas producing the most accurate values of φ in the conditions of loss of SFSP cooling were selected. In addition, a relation that allows one to perform more accurate calculations of steam volume fractions in the conditions of loss of SFSP cooling was derived based on the Fedorov formula in the two-group approximation.

Efficient radiation protection of the public and personnel requires detecting an accident-initiating event quickly. Specifically, if a heat-exchange tube in a steam generator is ruptured, the 16N radioactive nitrogen isotope, which contributes to a sharp increase in the steam activity before the turbine, may serve as the signaling component. This isotope is produced in the core coolant and is transported along the circulation circuit. The aim of the present study was to model the transport of 16N in the primary and the secondary circuits of a VVER-1000 reactor facility (RF) under nominal operation conditions. KORSAR/GP and RELAP5/Mod.3.2 codes were used to perform the calculations. Computational models incorporating the major components of the primary and the secondary circuits of an NPP-2006 RF were constructed. These computational models were subjected to cross-verification, and the calculation results were compared to the experimental data on the distribution of the void fraction over the steam generator height. The models were proven to be valid. It was found that the time of nitrogen transport from the core to the heat-exchange tube leak was no longer than 1 s under RF operation at a power level of 100% Nnom with all primary circuit pumps activated. The time of nitrogen transport from the leak to the γ-radiation detection unit under the same operating conditions was no longer than 9 s, and the nitrogen concentration in steam was no less than 1.4% (by mass) of its concentration at the reactor outlet. These values were obtained using conservative approaches to estimating the leak flow and the transport time, but the radioactive decay of nitrogen was not taken into account. Further research concerned with the calculation of thermohydraulic processes should be focused on modeling the transport of nitrogen under RF operation with some primary circuit pumps deactivated.

Colorectal cancer is one of the most common cancers in the world. It is well known that the chronic inflammation can promote the progression of colorectal cancer (CRC). Recently, a number of studies revealed a potential association between colorectal inflammation, cancer progression, and infection caused by enterotoxigenicBacteroides fragilis(ETBF). Bacterial enterotoxin activates spermine oxidase (SMO), which produces spermidine and H2O2as byproducts of polyamine catabolism, which, in turn, enhances inflammation and tissue injury. Using qPCR analysis, we estimated the expression ofSMOXgene and ETBF colonization in CRC patients. We found no statistically significant associations between them. Then we selected genes involved in polyamine metabolism, metabolic reprogramming, and inflammation regulation and estimated their expression in CRC. We observed overexpression ofSMOX,ODC1,SRM,SMS,MTAP,c-Myc,C/EBPβ(CREBP), and other genes. We found that two mediators of metabolic reprogramming, inflammation, and cell proliferation c-Myc and C/EBPβmay serve as regulators of polyamine metabolism genes (SMOX, AZIN1, MTAP, SRM, ODC1, AMD1, andAGMAT) as they are overexpressed in tumors, have binding site according to ENCODE ChIP-Seq data, and demonstrate strong coexpression with their targets. Thus, increased polyamine metabolism in CRC could be driven by c-Myc and C/EBPβrather than ETBF infection.

Carotid paragangliomas (CPGLs) are rare neuroendocrine tumors of the head and neck. "Germline" and somatic mutations in a number of genes were shown to be associated with the development of CPGLs; however, molecular mechanisms of the tumor pathogenesis have not been fully understood. In the work, we have used whole exome sequencing data of 52 CPGLs obtained earlier. Using MutSigCV, the search for genes with high mutation rate was performed. Thirty four genes (MADCAM1, SARM1, ZFPM1, CTDSP2, DSPP, POTED, ANP32B, FRG2B, BAGE3, CCDC89, ACOT2, KRTAP10-1, ATXN1, GXYLT1, MUC2, AQP7, TMPRSS13, KRTAP4-3, PRR21, PSPH, PLBD1, ZNF595, IGSF3, PRR16, FAM157A, KCNJ12, HYDIN, IGFBP2, KIAA1671, DISC1, MUC6, XKR3, HRNR, and MUC4) potentially associated with the CPGL initiation and progression were revealed. The involvement of these genes in the pathogenesis of CPGLs was first shown, and possible mechanisms of their participation in that were discussed.

Several relationships were analyzed to calculate the heat transfer during boiling water with underheating involving these implemented in RELAP5 and KORSAR codes. The errors of the presented relationships are evaluated using modeling of the experimental data on boiling with underheating in vertical channels. It is shown that the quantitative evaluations of the wall temperature during boiling with underheating, which are obtained applying the codes, can be refined by means of the involvement of the alternative trailing relationships, which is topical in connection with the influence of surface boiling on the intensity of the nodular (hot-spot) corrosion of the fuel element claddings.

A perfectly reflecting (Dirichlet) boundary condition at the edge of an impenetrable magnetic-flux-carrying tube of nonzero transverse size is imposed on the charged massive scalar matter field which is quantized outside the tube on a plane which is transverse to the tube. We show that the vacuum polarization effects outside the tube give rise to a macroscopic force acting at the increase of the tube radius (if the magnetic flux is held steady)., Comment: 12 pages, 7 figures, some explanations and references added. arXiv admin note: text overlap with arXiv:1109.3068

The effect of sulfated polysaccharides on the efficiency of the infection of mouse transplantable fibroblast SC�1 and NIH�3T3 cell lines by replicat ioncompetent recombinant Moloney murine leukemia virus (MoMuLV), which carries the eGFP gene, was invest igated. It was found that sulfated polysaccharides have no cytostatic and cytotoxic effects on SC�1 and NIH�3T3 cells in the concentration range of 0.01-100 µg/mL and have virucidal activity against MoMuLV. Polysacchar ides in the indicated concentrations inhibit MoMuLV infection that prevents the further development of viral infection. It was shown that sulfated polysaccharides are also effective inhibitors of other retroviruses, including lentiviruses, which use sulfated polysaccharides as pri� mary cell receptors.

Multiple changes in the genome, transcriptome, and proteome are frequent in cancer cells. A search for molecular markers based on DNA, mRNA, or proteins is a main method to develop early specific diagnostics for cancer. While universal markers are still unavailable, similar trends are known for the expression patterns of particular genes in certain epithelial tumors. A bioinformatic screening of transcriptomic databases identified the NETO2 gene as a new potential promising marker of renal cancer. A substantial increase in NETO2 mRNA level was detected in 90% clear-cell renal cell carcinomas, 70% of non-small cell lung cancers, and 50% of papillary renal cancers by real-time PCR. The NETO2 mRNA level was increased to a lesser extent in cervical carcinoma and colon cancer and tended to decrease in cancer of the stomach. The NETO2 gene, which codes for a membrane glycoprotein with an unclear function, was assumed to provide a new promising marker for early diagnosis in renal cancer and non-small cell lung cancer.

The dynamics of in vitro development of reconstructed bovine embryos activated at various time after electrofusion was studied. The in vitro mature oocytes without zona pellucida enucleated using the blind method were taken as cytoplasts. Fetal fibroblasts were used as the nuclei source. Approximately 40% of embryos activated between 3 and 3.2 hours after electrofusion developed to blastocysts. The efficiency of in vitro development of cloned embryo of cloned embryo did not decrease when the time between electrofusion and activation was extended up to 4–5 hours. The pattern of more successful development of in vitro reconstructed embryos was found using enucleated oocytes, extrusion the first polar body to 18 hours in comparison with oocytes matured in vitro afterwards, as cytoplasts.

The organization of the water-chemistry regime in the loop of a passive safety system, whose purpose is emergency removal of heat from the core of a nuclear power reactor, is examined. It is shown that a selfregulated water-chemistry regime in which gaseous products of radiolysis can be dissolved in water coolant and recirculated into the irradiation zone, which will intensify liquid-phase radiation-chemical reactions of hydrogen with oxygen and organic release of gases from the liquid phase into the vapor-gas phase of the coolant, can arise in the loop of a passive safety system. This will result in the establishment in the loop of dynamic equilibrium between the release and dissolution of gases and will enable prolonged functioning of the safety system without intervention from the outside. The physicochemical and technical criteria for the appearance of a self-regulated water-chemistry regime for closed loops with natural circulation of the two-phase coolant are formulated and substantiated.

We consider two procedures for evaluating the influence of nondensables on steam condensation taking into account the integral effect from interaction between the water-chemistry and thermal-hydrodynamic processes occurring in the primary coolant circuit of a nuclear power installation (NPI). Results from calculations of the passive safety system of an NPI are given.

An approach to simulating the water-chemistry regime for transient and stationary operating states of a nuclear power system is proposed. The approach is based on the designer’s philosophy. The first loop of the nuclear power system is divided into standard units. The special features of the reactor design and the crux of the problem being solved determine the number of units and the interaction between them. The units can be structural components of the loop as well as coolant components. The thermochemical and radiation-chemical transformations of the components of the water coolant are simulated at each unit. The interaction between the physicochemical processes at the units is expressed in the flow of the coolant components between them. The approach developed is illustrated on the analysis of the water-chemistry regime in implementing a passive safety system — a promising solution geared toward increasing the operational safety of the first loop of a nuclear power system.

The optical properties of a number of crystals such as quartz leucosapphire and calcium and barium fluorides are experimentally investigated in the spectral range λ = 110–250 nm under conditions of their direct contact with an intensely emitting gas–plasma medium. The broadband UV radiation of power density I 0 ∼ 106– 4 × 107 W/cm2 is generated with the aid of light-erosion and plasmadynamic injectors in a vacuum and gases of different chemical compositions. The possibility is demonstrated of effective transport of powerful fluxes of UV radiation through the given materials during the formation at their surface of a gas layer optically dense for the short-wave UV radiation.

The starfish Asterias rubens is one of the most abundant echinoderm species in the White, Barents, North, and Baltic Seas. This species is an important component of marine ecosystems and a model object for certain biological studies, in particular those requiring quantitative estimation of gene expression. As a rule, expression at the transcriptional level is estimated by real-time qPCR using the ΔΔCt method, which allows the comparison of the copy number of target gene transcripts in samples with unknown mRNA/cDNA concentration. Application of this method requires normalization of the results relative to genes with stable expression levels (reference genes). The identification of reference genes is still a challenging task since data of this kind are missing for certain taxa, whereas the use of "standard" endogenous control genes without additional tests might lead to erroneous conclusions. We performed a preliminary analysis of the expression of many housekeeping genes in the pyloric ceca of A. rubens by high-throughput sequencing under normal and heat shock conditions. For one of them, the ubiquitin gene UBA52, low variation of expression (not greater than 2-fold) was shown using real-time qPCR. Tissues of pyloric ceca of normal adults and underyearlings and of adults after heat shock were used. The data obtained suggest that the UBA52 gene may be used as reference for normalization of gene expression at the mRNA level in the starfish A. rubens and probably in closely related species.

Glycolysis is a main catabolic pathway of glucose metabolism, accompanied by ATP synthesis. More than 30 enzymes are involved in glycolysis, and genes that encode them can be considered housekeeping genes due to the high conservatism and evolutionary antiquity of the process. We studied the expression of these genes in kidney papillary cancer and planocellular lung cancer via the bioinformatic analysis of transcriptome database and method of quantitative real time PCR. Quantitative analysis of mRNA level demonstrated that only a part ofgenes that encode glycolysis enzymes maintain relatively stable mRNA level, including the HK1, ADPGK, GPI, PGK1, and PKM2 genes in kidney papillary cancer and the ADPGK, ALDOA, GAPDH, PGK1, BPGM, ENO1, and PKM2 genes in planocellular lung cancer. The frequent increase in the mRNA expression of PFKP, ALDOA, and GAPDH genes in kidney cancer, as well as the GPI gene in lung cancer, were detected for the first time by real time PCR. For other genes, their differential expression was demonstrated; the cases of both a decrease and increase in the mRNA level were detected. Thus, several genes that can be used as control genes in transcriptome analysis by real time PCR in kidney and lung cancer, as well as a number of differentially expressed genes that can be potential oncomarkers, were identified.

Intramolecular cyclization of [N-benzyl(arylglyoxylimidoyl)]ketenes generated upon thermal decarbonylation of 4,5-diaroyl-1-benzylpyrrole-2,3-diones is accompanied by redox processes to form 3-aroyl-5-aryl-4H-furo[3,2-c]isoquinolin-2-ones and 3-benzoyl-4-benzylamino-5-phenyl-5H-furan-2-one (1). The molecular and crystal structure of compound 1 was studies by X-ray diffraction analysis. Under conditions of thermolysis, the starting pyrrole-2,3-diones are partially reduced to 4,5-diaroyl-1-benzyl-3-hydroxy-5H-pyrrol-2-ones.

Bovine embryos are reconstructed with the use of fetal fibroblasts as donors of nuclei and enucleated oocytes without the zona pellucida as recipients. The stages of electrofusion and in vitro culturing of embryos without the zone pellucida up to the blastocyst stage is perfected.

In this chapter we propose a framework for development of the mathematical model of Metabolic Syndrome. The cornerstone of the model is “adipose tissue expandability hypothesis”, which treats long-term increase in FAs concentration in blood and their subsequent accumulation in muscle and liver as a main cause of decrease in insulin sensitivity and, consequently, MetS development. The key biological facts underlying the construction of MetS model have been collected and analyzed and the main requirements of the model have been formulated. To take these facts into account and meet the requirements formulated, we have developed a novel algorithm enabling us to combine kinetic models, which describe changes in metabolite (lipoproteins) concentrations due to biochemical transformations in blood and tissues, with the mathematical model of the molecular movement in blood flow.

A perfectly reflecting (Dirichlet) boundary condition at the edge of an impenetrable magnetic-flux-carrying tube of nonzero transverse size is imposed on the charged massive scalar matter field which is quantized outside the tube. We show that the vacuum polarization effects outside the tube give rise to a macroscopic force acting at the increase of the tube radius (if the magnetic flux is held steady). The Casimir energy and force are periodic in the value of the magnetic flux, being independent of the coupling to the space-time curvature scalar. We conclude that a topological defect of the vortex type can polarize the vacuum of only those quantum fields that have masses which are much less than a scale of the spontaneous symmetry breaking., Comment: 16 pages, 3 figures, 1 table. arXiv admin note: substantial text overlap with arXiv:1207.0224