330 research outputs found

    表紙、目次、投稿規程、執筆要領、執筆者紹介

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    Currently a protein/peptide-mediated gene delivery has been considered a promising approach in non-viral gene transfer. The previous investigations have shown that histones and other nuclear proteins might be effective vectors for gene transfer into cells. Transfection of eukaryotic cells by nucleic acid and histone complexes (histonefection) effectively occurs with various histone proteins. The presence of DNA-binding domains and specific signal sequences of nuclear location allows to use histones (H1/H5, H2A, H2B, H3, H4) and other nuclear proteins (such as HMG family proteins and histonelike prokaryotic proteins) for recombinant genes transfer. The positive charge of histone protein molecules enables electrostatic interaction with negatively charged molecules of nucleic acids and charge neutralization that facilitates the complexes penetration through a negatively charged cell membrane. Thus, histonefection is a promising method for non-viral transfer of recombinant nucleic acids in gene therapy

    Spores of puffball fungus Lycoperdon pyriforme as a reference standard of stable monodisperse aerosol for calibration of optical instruments

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    Advanced air quality control requires real-time monitoring of particulate matter size and concentration, which can only be done using optical instruments. However, such techniques need regular calibration with reference samples. In this study, we suggest that puffball fungus (Lycoperdon pyriforme) spores can be utilized as a reference standard having a monodisperse size distribution. We compare the Lycoperdon pyriforme spores with the other commonly used reference samples, such as Al2O3 powder and polystyrene latex (PSL) microspheres. Here we demonstrate that the puffball spores do not coagulate and, thus, maintain the same particle size in the aerosol state for at least 15 minutes, which is enough for instrument calibration. Moreover, the puffball mushrooms can be stored for several years and no agglomeration of the spores occurs. They are also much cheaper than other calibration samples and no additional devices are needed for aerosol generation since the fungal fruiting body acts as an atomizer itself. The aforementioned features make the fungal spores a highly promising substance for calibration and validation of particle size analyzers, which outperforms the existing, artificially produced particles for aerosol sampling. Furthermore, the L. pyriforme spores are convenient for basic research and development of new optical measurement techniques, taking into account their uniform particle size and absent coagulation in the aeroso

    Self-organization of conducting pathways explains electrical wave propagation in cardiac tissues with high fraction of nonconducting cells

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    Cardiac fibrosis occurs in many forms of heart disease and is considered to be one of the main arrhythmogenic factors. Regions with a high density of fibroblasts are likely to cause blocks of wave propagation that give rise to dangerous cardiac arrhythmias. Therefore, studies of the wave propagation through these regions are very important, yet the precise mechanisms leading to arrhythmia formation in fibrotic cardiac tissue remain poorly understood. Particularly, it is not clear how wave propagation is organized at the cellular level, as experiments show that the regions with a high percentage of fibroblasts (65-75%) are still conducting electrical signals, whereas geometric analysis of randomly distributed conducting and non-conducting cells predicts connectivity loss at 40% at the most (percolation threshold). To address this question, we used a joint in vitro-in silico approach, which combined experiments in neonatal rat cardiac monolayers with morphological and electrophysiological computer simulations. We have shown that the main reason for sustainable wave propagation in highly fibrotic samples is the formation of a branching network of cardiomyocytes. We have successfully reproduced the morphology of conductive pathways in computer modelling, assuming that cardiomyocytes align their cytoskeletons to fuse into cardiac syncytium. The electrophysiological properties of the monolayers, such as conduction velocity, conduction blocks and wave fractionation, were reproduced as well. In a virtual cardiac tissue, we have also examined the wave propagation at the subcellular level, detected wavebreaks formation and its relation to the structure of fibrosis and, thus, analysed the processes leading to the onset of arrhythmias. © 2019 Kudryashova et al

    Epistemological risk aspects

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    The paper considers risk in the context of the main characteristics of non-classical epistemology. It states that non-classical epistemology is characterized by transformation, according to which the major priority of cognitive activity shifts the focus from the present to the past. In this situation a subject is keen not on what he or she has learnt but on what can be learnt. Truth being a crucial criterion of scientific knowledge is becoming of less priority, while risk is becoming more and more significant and acts as one of the major epistemology measurements. Risk is gaining the status of epistemological phenomenon, which shows a growing degree of uncertainty as a cognitive process background and the necessity for a subject to learn the world (make decisions) under the conditions of uncertainty degree strengthening. The author states that risk is a comprehensive notion and it obtains a base value for all other aspects of its application, specifically, in the role of epistemological phenomenon

    Identification of electrofacies on the basis of well logging to determine sedimentation environment of horizon JK[2] in Em-Egovskoe field (Western Siberia)

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    Well logging results are one of the ways to study the buried terrigenous rocks genesis. To ensure the most objective characterization of the rock and identification of electrofacies it is necessary to use a complex geological and geophysical survey. The comprehensive investigations of environmental conditions based on well logging have been performed for the horizon JK[2] of Tumenskoe formation in Em-Egovskoe area, Krasnoleninskoe field (Western Siberia). The defined electrofacies were compared with the results of earlier conducted granulometric and mineralogical analyses. The totality of research provided for a conclusion that the investigated sediments of horizon JK2 had been formed within the destructive tidal delta. Thus, objective facies prediction can only be ensured by analyzing core and well logging data comprehensively
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