On the choice of temperature profile at solving the heat conduction equation in spherical coordinates by the method of thermal balance integral

Solutions of the heat conduction equation for a sphere and an area limited from within by a spherical cavity have been obtained by means of the integrated method. The influence of the choice of the temperature profile on efficiency of the approached analytical solution is shown. The variant of solution specification in transitive area is offered

Effect of Laser Modification on Composite Films with Nanodispersed SiO2

ABSTRACT: Introduction. This research is aimed at studying the effect of laser modification on composite films obtained on the basis of polyimide track (nuclear) membranes and filled with nanodispersed SiO2; to change their optical and structural properties. Materials and research methods. Polyimide track (nuclear) membranes were used as a polymer matrix. Track diameter is 200 nm, membrane thickness is 25 μm. The tracks were filled with nanosized SiO2 by hydrolysis of tetraethoxysilane in the presence of track membranes. For composite film surface modification, we used ytterbium pulsed fiber laser Minimarker 2-20 A4 PA. We studied the change in the surface microscopy of composite films, their optical density, IR-Fourier spectra and surface wettability depending on laser treatment. Results and discussion. The authors have found the possibility of creating a composite film based on a polyimide track (nuclear) membrane and nanodispersed SiO2 by hydrolysis of tetraethoxysilane in the presence of a membrane. It is shown with the energy dispersive analysis method that silicon oxide has completely filled the pore volume of the track membrane. Laser modification of the composite material surface (composite film) leads to an increase in the contact angle of wetting from θ = 66.75 ± 1.55° to θ = 101.52 ± 3.03°. Thus, the material acquires hydrophobic properties. Also, the laser films modification has a positive effect on the transmittance of the films, namely, this coefficient increases. The greatest change is observed in the infrared region of еmitted spectrum, the average increase in transmission is +70.48%. Conclusion. The obtained results of the study are of great importance for understanding the mechanisms of creating composite films with improved optical properties, which can later be used to create composite films with desired optical properties for various application

Роль метилирования промоторов герпесвирусов в реализации патогенного потенциала на примере болезни Марека

Marek’s disease virus is ubiquitous and can harm not only poultry, but also be oncogenic for humans. VBM and malignant tumors induced by them are a convenient and accessible natural model for studying herpesvirus-associated carcinogenesis. To date, according to our observations, there are additional risks of human infection with the Marek’s disease virus - the disease began to appear in broiler chickens 30 days and older, i.e. contact with poultry meat carries a risk of infection. In addition, COVID-19 disease may be accompanied by folic acid deficiency, i.e. a violation of the folate cycle in humans, which increases the risk of manifestation of diseases associated with DNA viruses, since a violation of the folate cycle can reduce the activity of DNA methylation, incl. viral DNA. Methylation is carried out enzymatically in the first minutes after DNA replication, i.e. postreplicatively. Since the DNA nucleotide sequence does not change, methylation is essentially an epigenetic event. We have studied the relationship between the methylation of promoters of the Marek’s disease virus and the copy number of the virus. The assessment of the presence or absence of methylation, as well as partial methylation, was carried out on the basis of identifying the difference between the threshold cycles dC(t). The presence of unmethylated sites included in the studied promoter sequence was detected on the basis of the ability of methylsensitive restrictases AciI and GlaI. A correlation was found between the concentration of genomic DNA of the Marek’s disease virus serotype 1 strain CVI 988 in cell culture and the presence of demethylated CpG islands in the composition of promoters located at position 9413-9865 bp. and 127943 - 128193 b.p. genomic DNA of the virus. The data obtained make it possible to explain the mechanism of the increase in the pathogenicity of herpesvirus infections under conditions of a decrease in the activity of viral DNA methylation in the body.Вирус болезни Марека (ВБМ) имеет повсеместное распространение и может не только наносить вред домашней птице, но и обладать онкогенностью для человека. ВБМ и индуцируемые ими злокачественные опухоли являются удобной и доступной естественной моделью изучения канцерогенеза, ассоциированного с герпесвирусами. На сегодняшний день, по нашим наблюдениям, появились дополнительные риски заражения людей вирусом болезни Марека – болезнь начала появляться у цыплят-бройлеров 30 дней и старше, т.е. контакт с мясом птицы несет риск заражения. Помимо этого, заболевание COVID-19 может сопровождаться дефицитом фолиевой кислоты, т.е. нарушением фолатного цикла у людей, что повышает риск манифестации заболеваний, связанных с ДНК-вирусами, так как нарушение фолатного цикла способно снизить активность метилирования ДНК, в т.ч. вирусной ДНК. Метилирование осуществляется ферментативно в первые минуты после репликации ДНК, т.е. пострепликативно. Поскольку нуклеотидная последовательность ДНК при этом не меняется, метилирование по сути своей – событие эпигенетическое. Нами была изучена зависимость между метилированием промоторов вируса болезни Марека и копийностью вируса. Оценка наличия или отсутствия метилирования, так же как и частичного метилирования, осуществлялась на основе выявления разницы между пороговыми циклами dC(t). Наличие неметилированных сайтов, входящих в состав изучаемой промоторной последовательности, выявлялось на основе способности метилчувствительных рестриктаз AciI и GlaI. Была обнаружена корреляционная зависимость между концентрацией геномной ДНК вируса болезни Марека 1-го серотипа штамма CVI988 в культуре клеток и наличием деметилированных CpG-островков в составе промоторов, локализующихся в положении 9413–9865 и 127943–128193 п.н. геномной ДНК вируса. Полученные данные позволяют объяснить механизм повышения патогенности герпесвирусных инфекций в условиях снижения активности метилирования вирусной ДНК в организме

A Conceptual Modelling Approach to Visualising Linked Data

Increasing numbers of Linked Open Datasets are being published, and many possible data visualisations may be appropriate for a user's given exploration or analysis task over a dataset. Users may therefore find it difficult to identify visualisations that meet their data exploration or analyses needs. We propose an approach that creates conceptual models of groups of commonly used data visualisations, which can be used to analyse the data and users' queries so as to automatically generate recommendations of possible visualisations. To our knowledge, this is the first work to propose a conceptual modelling approach to recommending visualisations for Linked Data

Effect of electrochemical modification of titanium hydride fraction on oxygen content in surface and deep layers

The paper presents a study of the microstructure and oxygen concentration in the surface and deep layers of fractions of unmodified titanium hydride and titanium hydride modified by electrodeposited layers of Ti and Cu at temperatures of 300 °C–900 °C. The composition of the oxide layer and the concentration of titanium and oxygen atoms are estimated. It is shown that an increase in the thickness and compaction of the oxide layer with increasing temperature prevents the penetration of oxygen into the deep layers of the unmodified fraction of titanium hydride. Modification of titanium hydride by electrochemical deposition of metallic titanium at a temperature of 700 °C reduces the oxygen concentration in titanium hydride at a layer depth of 50 μ m from 35 wt% to 12.5 wt%. Electrodeposition of coatings based on titanium and copper at 700 °C reduces the oxygen concentration to 9.2 wt%, which may be due to the protective mechanism of the formed copper titanate layer. At 900 °C, in the modification layer based on titanium and copper, due to the eutectoid transformation of the β -phase of titanium, the process of contact melting occurs and a multiphase zone is formed. The oxygen concentration at a layer depth of 50 μ m is no more than 12.4 wt%