DNA sequencing is an essential task of modern molecular genetic research. Its fundamental parameter is the accuracy of decoding. In this work, we determined the maximum lengths of DNA fragments, ...obtained by the Sanger method and sequenced with an accuracy of 99%, in a polymer based on linear poly(
N
,
N
-dimethylacrylamide) PDMA-6 for capillaries 50 cm long to the optical window of the detector of a Nanophore 05 domestic genetic analyzer and an imported GA 3500xL genetic analyzer. The results of DNA sequencing obtained by various analysis algorithms were compared. The parameters of the analysis algorithms were selected, ensuring best results of DNA sequencing in using the PDMA-6 polymer.
Specific features of using membrane reactors for hydroformylation (oxo-synthesis) were analyzed. The main attention is given to the hydroformylation of olefins with an average chain length (C
6
–C
9
...), which are important precursors of organic synthesis. The catalysts compatible with the membrane reactor and prospects of using composite polymer and inorganic membranes are considered. A high permeability of the membranes to aldehydes makes it possible to intensify the oxo-synthesis process due to the
in situ
removal of the reaction product and also to reduce costs of separating a feedstock—product—catalyst mixture.
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•PIM-1 material was used for solute fractionation by means of solvent swing adsorption (SSA).•Solvents used in SSA can be regenerated by PIM-1 membranes.•PIM-1 can be turned from ...solvent-selective into solute-selective membrane by changing the solvent nature.
A concept is demonstrated for the separation of two organic solutes from a common solvent by solvent swing adsorption (SSA), coupled with organic solvent nanofiltration (OSN) for solvent recycling. The polymer of intrinsic microporosity PIM-1 was utilized both for the adsorbent and for the nanofiltration membrane. For adsorption from solution in ethanol or water–ethanol (30/70) mixture, PIM-1 showed high affinity for a neutral solute (Oil Red O) with negligible uptake of an anionic solute (Remazol Brilliant Blue R). The obtained equilibrium values of distribution coefficient K revealed that Oil Red O can be concentrated in PIM-1 by 4300 times from its ethanol solution, and this value can be significantly improved up to 53,000 times in the case of water/ethanol (30/70) binary mixture. Such difference in the affinity of neutral solute to PIM-1 was explained by means of competitive sorption between solute and solvent molecules, and a clear relationship between distribution coefficient K and solvent solubility parameter was observed. The adsorbent could be regenerated by washing with a less polar solvent (toluene), which gave almost quantitative desorption of the neutral solute (K=6). PIM-1 membranes as cast and after cross-linking were also successfully utilized for solvent recovery. It was demonstrated that PIM-1 membranes can possess either solvent-selective transport or solute-selective transport in OSN, depending on the nature of the solvent.
The Planar Laser Induced Fluorescence optical technique is used to measure the droplet temperature field, and the Micro Particle Image Velocimetry – the velocities of natural convection in the ...droplet. We focus on the convection, vortex formation centers, convection velocities, and the influence of convection on the temperature in different droplet sections. The most common tracer particles are used (Al2O3, TiO2, polyamide). Differences in the temperature fields of evaporating droplets with tracers and without them are analyzed. We compare the reliability of measuring droplet temperature using Planar Laser Induced Fluorescence and fast-response thermocouples. The concentrations of tracers are varied to establish the ranges in which the fields of temperature and convection velocities can be reliably measured in rapidly heated and evaporating droplets. We study the influence of typical holder materials on droplet heating rates. Metal rods, wires, and nichrome wires are used. The focus is on illustrating the influence of the holder type and material on the droplet temperature field, its heating and evaporation rates, as well as its lifetime. We consider typical schemes of droplet fixation on holders, as well as the main differences in the fields of temperature and convection velocities in different droplet sections. As a result, we have obtained the concentrations of Al2O3 and TiO2 tracers that make it possible to use both Planar Laser Induced Fluorescence and Micro Particle Image Velocimetry at the same time. Examples are given of particle agglomeration and photobleaching. The use of polyamide particles as tracers is found not feasible for evaluating the convection rates in droplets, because they are displaced from the deep layers of a droplet to the surface. It is established that if a Rhodamine B solution contains Al2O3 and TiO2 tracers, the fluorophore settles on those particles, which may degrade the accuracy of temperature measurement using Planar Laser Induced Fluorescence. The experimental findings are important to develop the fields of research into the conditions and characteristics of heating droplets, films, and liquid jets, using Planar Laser Induced Fluorescence and Micro Particle Image Velocimetry.
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•Tracers influence on temperature can be evaluated with adjustment coefficients•Optimal concentrations and types of tracers were established•Heating and evaporation rates differ no more than 10–15% with adding tracers•Droplet lifetimes can differ 15–20% with different materials of holders•Temperature and velocity in droplets with different fixation schemes were established
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•Temperature field in the water droplet is highly non-homogeneous during the heating.•PLIF allows observing temperature fields in droplets even at high air temperatures.•Maximum ...temperature differential from the droplet surface to centre can achieve 30–40°C.•Nonlinear evaporation rate dependences are plotted for the main parameters.•Water evaporation rate increases dozens of times during the droplet heating.
Gas-steam-droplet technologies are widely used in systems operating at high temperatures ranging between 400 and 2000°C, namely: fire-fighting systems, thermal fluid cleaning, fuel compounding, industrial waste gasification and evaporation systems for advanced fuel components, cleaning of thermally loaded surfaces of power equipment, etc. System parameters are usually selected empirically via multiple tests and continuous trial operation of appropriate units, aggregates, assemblies, and installations. This situation is caused by insufficient basic knowledge of conditions and parameters of high-temperature (over 500°C) heating and evaporation of water and water-based emulsions, solutions, and slurries. Limited information is available regarding the evaporation rates dependent on the temperature of gaseous medium. Consequently, the up-to-date evaporation models allow the researchers to achieve adequate values (in good agreement with the experiment) of evaporation rates at air temperatures not exceeding 300–400°C. The paper presents a set of experiments on water droplets with the size ranging from 1 to 2mm, which is used to create the information database on high-temperature evaporation parameters. The approach to measuring the evaporation rate involves observation of the droplet size or more exactly its mean radius, and recording the time of its existence. A high-speed video camera and Tema Automotive software with different tracking algorithms are used for experimental observations. During gas heating, the distribution of highly non-homogeneous and non-steady temperature field in evaporating water droplets is detected by the hardware and software cross-correlation system and Planar Laser-induced Fluorescence optical diagnostics. Instantaneous and medium evaporation rates are computed for the whole period of the droplet lifetime. Highly nonlinear evaporation rate dependences are suggested for gas temperatures and the water droplet surface, size, and time of gas heating. Approximate relationships are described for the prediction of evaporation rates depending on the basic parameters. The evaporation rate is shown to increase several-fold during the heating of a water droplet in a high-temperature gaseous medium. The experimental data are described most accurately by exponential dependences of water evaporation rate versus the airflow temperature and velocity. This result makes it possible to predict the corresponding highly nonlinear dependences of evaporation rate versus the density of convective heat flux and the overall thermal conditions in the industrial chambers, evaporators, heat exchangers, etc. The mathematical expressions obtained can be used to identify the effective conditions of water droplet heating in a large group of high-temperatures applications as well as for developing high-temperature liquid evaporation models.
Mutations in pancreatic duodenal homeobox 1 (PDX-1) can cause a monogenic form of diabetes (maturity onset diabetes of the young 4) in humans, and silencing Pdx-1 in pancreatic β-cells of mice causes ...diabetes. However, it is not established whether epigenetic alterations of PDX-1 influence type 2 diabetes (T2D) in humans. Here we analyzed mRNA expression and DNA methylation of PDX-1 in human pancreatic islets from 55 nondiabetic donors and nine patients with T2D. We further studied epigenetic regulation of PDX-1 in clonal β-cells. PDX-1 expression was decreased in pancreatic islets from patients with T2D compared with nondiabetic donors (P = 0.0002) and correlated positively with insulin expression (rho = 0.59, P = 0.000001) and glucose-stimulated insulin secretion (rho = 0.41, P = 0.005) in the human islets. Ten CpG sites in the distal PDX-1 promoter and enhancer regions exhibited significantly increased DNA methylation in islets from patients with T2D compared with nondiabetic donors. DNA methylation of PDX-1 correlated negatively with its gene expression in the human islets (rho = -0.64, P = 0.0000029). Moreover, methylation of the human PDX-1 promoter and enhancer regions suppressed reporter gene expression in clonal β-cells (P = 0.04). Our data further indicate that hyperglycemia decreases gene expression and increases DNA methylation of PDX-1 because glycosylated hemoglobin (HbA1c) correlates negatively with mRNA expression (rho = -0.50, P = 0.0004) and positively with DNA methylation (rho = 0.54, P = 0.00024) of PDX-1 in the human islets. Furthermore, while Pdx-1 expression decreased, Pdx-1 methylation and Dnmt1 expression increased in clonal β-cells exposed to high glucose. Overall, epigenetic modifications of PDX-1 may play a role in the development of T2D, given that pancreatic islets from patients with T2D and β-cells exposed to hyperglycemia exhibited increased DNA methylation and decreased expression of PDX-1. The expression levels of PDX-1 were further associated with insulin secretion in the human islets.
The article presents the measuring results of droplet velocity and temperature fields using non-contact optical methods: Particle Image Velocity (PIV), Planar Laser Induced Fluorescence (PLIF) and ...Thermal imager. The novelty of the work is that the influence of free convection in gas and liquid is investigated experimentally and theoretically and that the key criteria affecting heat and mass transfer are determined. The analysis of experimental data has shown that in the initial period of water drop evaporation, the predominant role in the heat exchange is played by the thermal Marangoni convection. However, for an aqueous salt solution, in spite of the strong influence of the surfactant, the dominant role passes to the solutal Marangoni convection (MaC). In the first seconds after the drop falling, convection and heat transfer in liquid are maximal. Under such conditions it is important to realize an accurate numerical simulation to assess the degree of wall cooling and calculate the non-stationary evaporation. When simulating heat transfer, it is incorrect to neglect free convection in gas or liquid due to their strong nonlinear influence on each other. The heat exchange in the drop is extremely conservative to convection in the liquid (the Peclet number Pe = 100 and the Nusselt number Nu = 4).
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•The droplet velocity decreases with a decrease in the Ma number.•The role of convection prevails over conduction for the droplet height above 1 mm.•The solutal Ma has a greater influence on heat transfer than the thermal Ma and Gr.
The economic and legal regime of the Russian Arctic is currently in its nascent stage of development. The Arctic has acquired the status of a special object of government control. However, not only ...new management tools are being formed to enhance the socio-economic development of the region, the borders of the management object themselves are changing - new territories are being included in the Arctic zone. Thus, the formation of the economic and legal regime of the Arctic zone and the incorporation of new territories into its spatial and economic structure not only go hand in hand, but are also of an interdependent nature. In addition, the historically established system of resettlement and distribution of productive forces and the resource potential of the territory should be considered and analyzed based on the new circumstances, strategic development goals and tasks of the spatial organization of the economy of the Arctic zone region. The purpose of this article is to identify urgent problems of the socio-economic development of the municipalities of the Republic of Karelia included in the Arctic zone of Russia, and to develop directions for overcoming them within the strategic priorities for the development of the Arctic zone of the Russian Federation. To achieve this goal, we analyzed the current stage in the formation of the economic and legal regime of the Russian Arctic, examined the features of the socio-economic development of the Karelian Arctic and the spatial organization of the economy, identified areas for improving the spatial organization of the economy of the region in the context of integration into existing projects for the development of the Arctic zone of the Russian Federation and its legal regime. The conclusion was made about the need to expand the Karelian Arctic in order to form an economic space that determines the complex development of the territory. An alternative is the integration of the Karelian Arctic into the emerging support zones of neighboring regions.
Genetics, epigenetics, and environment may together affect the susceptibility for type 2 diabetes (T2D). Our aim was to dissect molecular mechanisms underlying T2D using genome-wide expression and ...DNA methylation data in adipose tissue from monozygotic twin pairs discordant for T2D and independent case-control cohorts. In adipose tissue from diabetic twins, we found decreased expression of genes involved in oxidative phosphorylation; carbohydrate, amino acid, and lipid metabolism; and increased expression of genes involved in inflammation and glycan degradation. The most differentially expressed genes included ELOVL6, GYS2, FADS1, SPP1 (OPN), CCL18, and IL1RN. We replicated these results in adipose tissue from an independent case-control cohort. Several candidate genes for obesity and T2D (e.g., IRS1 and VEGFA) were differentially expressed in discordant twins. We found a heritable contribution to the genome-wide DNA methylation variability in twins. Differences in methylation between monozygotic twin pairs discordant for T2D were subsequently modest. However, 15,627 sites, representing 7,046 genes including PPARG, KCNQ1, TCF7L2, and IRS1, showed differential DNA methylation in adipose tissue from unrelated subjects with T2D compared with control subjects. A total of 1,410 of these sites also showed differential DNA methylation in the twins discordant for T2D. For the differentially methylated sites, the heritability estimate was 0.28. We also identified copy number variants (CNVs) in monozygotic twin pairs discordant for T2D. Taken together, subjects with T2D exhibit multiple transcriptional and epigenetic changes in adipose tissue relevant to the development of the disease.
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