IMPROVEMENT OF SPENT NUCLEAR FUEL COOLING SAFETY IN COOLING PONDS USING THERMOSIPHONS

В работе рассмотрен способ пассивного отвода остаточных тепловыделений отработавшего ядерного топлива (ОЯТ) в бассейне выдержки с помощью термосифонов для повышения безопасности в случае потери электроснабжения.The work considers a way of passive removal of residual heat from spent nuclear fuel in a cooling pond with the use thermosyphons in order to improve safety in case of power supply failure

Possibility of using the infrapatellar (Hoffa’s) fat pad as a source of autologous stem cells

Stem cells are the basis for the creation of tissue-engineered structures in regenerative medicine. The most well-studied sources of stem cells are the embryo and bone marrow. The use of embryonic cells is associated with ethical problems, and the collection of bone marrow is accompanied by invasive procedures. Using adipose tissue as a source of stem cells avoids these problems. But the collection of adipose tissue requires additional interventions, which does not exclude the occurrence of cosmetic defects. Aim of the study was to investigate the possibility of using mesenchymal stem cells (MSCs) isolated from the infrapatellar (Hoffa’s) fat pad.Material and methods. As a source of MSCs, tissue samples of Hoffa’s fat pad removed during the operation were used (8 cases), as a control - MSCs isolated from human adipose tissue (6 cases). MSCs were isolated using an enzymatic method. At the 3rd passage, phenotyping with specific antibodies against CD34, CD45, CD73, CD90, CD105 was performed by flow cytometry. Differentiation in the chondro- and osteogenic direction was carried out at the 3rd passage with the appropriate differentiation media. Chondrogenic differentiation was confirmed by staining with alcian blue, osteogenic - staining according to von Kossa.Results and discussion. Statistically significant decrease in CD105 expression, increase in CD73, CD34 expression and lack of adequate differentiation under standard conditions of differentiation media by MSCs isolated from the Hoffa’s fat pad compared to control was found. The data obtained indicate a discrepancy between the cells isolated from the Hoffa’s fat pad and the requirements for MSCs.Conclusion. The infrapatellar (Hoffa’s) fat pad_cannot be used as a source of standardized MSCs

Method for preserving the viability of a chicken embryo with a shell defect in experiment

The egg has always been and remains an ideal object for conducting various scientific research. An egg is an isolated egg cell outside the mother’s body. Therefore, it is an ideal object for studying embryogenesis and performing various manipulations during embryogenesis and before the birth of a viable organism. The existing methods allow conducting experimental manipulations with the embryo in  situ, inside the egg shells without damaging them. However, the achievement of ideal parameters for closing the defect of the fertilized egg shell in the experiment is the key to  the successful completion of the experiment. Periods of embryogenesis, especially at the last stage, when osteogenesis occurs, require the presence of a sufficient amount of calcium ions in the metabolism of the developing chicken, which are vital for the formation of a full-fledged chicken.The aim: to develop an optimal method for closing the defect and fixing the egg shell after manipulation or during the experiment.Materials and methods. The experiment was carried out on fertile eggs of the breed of chickens – meat breed of broilers Ross-308 (ROSS-308), JSC Poultry Farm “NovoBaryshevskaya” (Koltsovo, Novosibirsk Region, Russian Federation). In the experiment, 120 fertilized eggs were used. Eggs weighing 60–70 g were incubated at a temperature of 37.5–38.0 °C and 50–55 % humidity. Comparative anatomical and physiological parameters were evaluated on the 7th, 14th, 20th day of incubation and on the 1st day of the postnatal period. In the experimental group, the shell defect was covered with a fragment of the egg shell of the donor. Incubation was carried out in an incubator – a household incubator “Nesushka” (Novosibirsk, Russian Federation).Results. The proposed method of fixing and closing the defect of the fertilized egg shell excludes the use of foreign materials that have an adverse effect on the development of the embryo. There were no anatomical and physiological deviations in the chicks of the study group when comparing the indicators with the parameters in the comparison group and the Hamburger – Hamilton classification

Properties Of The Hard X-ray Radiation From The Black Hole Candidates: Cygnus X-1 And 1E1740.7-2942

The entire dataset of the GRANAT/SIGMA observations of Cyg X-1 and 1E1740.7-2942 in 1990-1994 was analyzed in order to search for correlations between primary observational characteristics of the hard X-ray (40-200 keV) emission - hard X-ray luminosity, hardness of the spectrum (quantified in terms of the best-fit thermal bremsstrahlung temperature kT) and the RMS of short-term flux variations. Although no strict point-to-point correlations were detected certain general tendencies are evident. It was found that for Cyg X-1 the spectral hardness is in general positively correlated with relative amplitude of short-term variability. The correlation of similar kind was found for X-ray transient GRO J0422+32 (X-ray Nova Persei 1992). For both sources an approximate correlation between kT and L_X was found. At low hard X-ray luminosity - below 10E37 erg/sec - kT increases with L_X. At higher luminosity the spectral hardness depends weaker or does not depend at all on the hard X-ray luminosity. The low luminosity end of these approximate correlations (low kT and low RMS) corresponds to extended episodes of very low hard X-ray flux occurred during SIGMA observations.Comment: 6 pages, 7 figures, uses mn.sty, epsf.sty, psfig.tex; Accepted for publication in MNRAS; Also available at http://hea.iki.rssi.ru/~sik/PAPERS/mnras97.ps.gz (gzipped PostScript

Using Relational Verification for Program Slicing

Program slicing is the process of removing statements from a program such that defined aspects of its behavior are retained. For producing precise slices, i.e., slices that are minimal in size, the program\u27s semantics must be considered. Existing approaches that go beyond a syntactical analysis and do take the semantics into account are not fully automatic and require auxiliary specifications from the user. In this paper, we adapt relational verification to check whether a slice candidate obtained by removing some instructions from a program is indeed a valid slice. Based on this, we propose a framework for precise and automatic program slicing. As part of this framework, we present three strategies for the generation of slice candidates, and we show how dynamic slicing approaches - that interweave generating and checking slice candidates - can be used for this purpose. The framework can easily be extended with other strategies for generating slice candidates. We discuss the strengths and weaknesses of slicing approaches that use our framework

A Study of the Learnability of Relational Properties: Model Counting Meets Machine Learning (MCML)

This paper introduces the MCML approach for empirically studying the learnability of relational properties that can be expressed in the well-known software design language Alloy. A key novelty of MCML is quantification of the performance of and semantic differences among trained machine learning (ML) models, specifically decision trees, with respect to entire (bounded) input spaces, and not just for given training and test datasets (as is the common practice). MCML reduces the quantification problems to the classic complexity theory problem of model counting, and employs state-of-the-art model counters. The results show that relatively simple ML models can achieve surprisingly high performance (accuracy and F1-score) when evaluated in the common setting of using training and test datasets - even when the training dataset is much smaller than the test dataset - indicating the seeming simplicity of learning relational properties. However, MCML metrics based on model counting show that the performance can degrade substantially when tested against the entire (bounded) input space, indicating the high complexity of precisely learning these properties, and the usefulness of model counting in quantifying the true performance

Nanoencapsulated capsaicin changes migration behavior and morphology of madin darby canine kidney cell monolayers

We have developed a drug delivery nanosystem based on chitosan and capsaicin. Both substances have a wide range of biological activities. We investigated the nanosystem’s influence on migration and morphology of Madin Darby canine kidney (MDCK-C7) epithelial cells in comparison to the capsaicin-free nanoformulation, free capsaicin, and control cells. For minimally-invasive quantification of cell migration, we applied label-free digital holographic microscopy (DHM) and single-cell tracking. Moreover, quantitative DHM phase images were used as novel stain-free assay to quantify the temporal course of global cellular morphology changes in confluent cell layers. Cytoskeleton alterations and tight junction protein redistributions were complementary analyzed by fluorescence microscopy. Calcium influx measurements were conducted to characterize the influence of the nanoformulations and capsaicin on ion channel activities. We found that both, capsaicin-loaded and unloaded chitosan nanocapsules, and also free capsaicin, have a significant impact on directed cell migration and cellular motility. Increase of velocity and directionality of cell migration correlates with changes in the cell layer surface roughness, tight junction integrity and cytoskeleton alterations. Calcium influx into cells occurred only after nanoformulation treatment but not upon addition of free capsaicin. Our results pave the way for further studies on the biological significance of these findings and potential biomedical applications, e.g. as drug and gene carriers

The Mode of Inheritance of Scheuermann’s Disease

The mode of Scheuermann’s disease inheritance and its phenotypic traits in probands and their relatives were studied in 90 pedigrees (90 probands and 385 relatives). The disorder was identified as a genetically related pathology inherited by autosomal dominant type, controlled by a mutant major gene, as a kyphotic deformity without signs of vertebral bodies’ anomaly and torsion. Morphological and biochemical studies showed disturbance in the structure of vertebral growth plate anterior aspects at the level of deformity, defects in proliferation and differentiation of chondrocytes, and change in proteoglycan spectrum in cells and matrix. Twelve candidate genes were studied in chondrocytes isolated from vertebral growth plates of patients with Scheuermann’s disease. The study results included disorder in the IHH gene expression and preservation of the expression of PAX1, two aggrecan isoforms, link protein, types I and II collagen, lumican, versican, growth hormone and growth factor receptor genes, and proliferation gene. Preservation of the SOX9 gene (transcription gene) probably indicates posttranscriptional genetic disorders. The study is under way