The state and problems of the metrological support of personal blood glucose monitors – glucometers, have been examined and analyzed. It is shown that at present glucometers, like other individual ...measuring instruments for medical applications, are unsuitable for use in the field of telemedicine since there is no metrological support for such measuring instruments. The main problem is the lack of reliable methods and means of remote verification, calibration and transmission of measurement results to medical institutions. The article proposes a method for remote verification of glucometers based on the use of a set of electrical resistances, the values of which correlate with the measured concentration of glucose in the blood. The proposed method has been successfully tested in practice.
The detection of CA 125 protein in buffer solution with a silicon-on-insulator (SOI)-based nanoribbon (NR) biosensor was experimentally demonstrated. In the biosensor, sensor chips, bearing an array ...of 12 nanoribbons (NRs) with n-type conductance, were employed. In the course of the analysis with the NR biosensor, the target protein was biospecifically captured onto the surface of the NRs, which was sensitized with covalently immobilized aptamers against CA 125. Atomic force microscopy (AFM) and mass spectrometry (MS) were employed in order to confirm the formation of the probe–target complexes on the NR surface. Via AFM and MS, the formation of aptamer–antigen complexes on the surface of SOI substrates with covalently immobilized aptamers against CA 125 was revealed, thus confirming the efficient immobilization of the aptamers onto the SOI surface. The biosensor signal, resulting from the biospecific interaction between CA 125 and the NR-immobilized aptamer probes, was shown to increase with an increase in the target protein concentration. The minimum detectable CA 125 concentration was as low as 1.5 × 10−17 M. Moreover, with the biosensor proposed herein, the detection of CA 125 in the plasma of ovarian cancer patients was demonstrated.
Dust particles obtained by filtering fresh snow collected from May to September 2017 in the vicinity of Vostok station in Antarctica were examined using a scanning electron microscope. The collection ...of dust particles contains 197 spherules ranging from 0.5 to 117 μm in diameter, the most abundant ones (n = 188) by far being iron oxide spherules. Analyses of meteorological and human activity data suggest an extraterrestrial origin of most of the spherical particles. The particle size distribution histogram showed a smooth increase in their number with decreasing size and a dramatic drop at sizes smaller than 3 μm. The number of spherical particles has an uneven distribution over time, with an intense peak in July 27–28, 2017 which correlates by dates with the peak of the Southern Delta Aquariids meteor shower. The size distribution of the particles collected during the same period indicates the presence of a mechanism that accelerates their fall to the Earth. We propose that they are effective centers of condensation of ice crystals in stratospheric clouds. Our data indicate that collection of micrometeorites with sizes of several microns from the fresh snow is possible, opening a new way for sampling micrometeorites, including separate meteor showers.
The level of the society human capital development in new technological order becomes the determining parameter of successful development. Glocalization processes are growing against the background ...of globalization, ensuring the integration of regional economies into technological and financial chains. The development of the continental and marine Arctic is accelerating. The most effective and environmentally safe development will take place in technologically advanced ecosystems that have created a favorable institutional environment. Both these factors depend on the level of human capital development. Only the country (region), which makes efforts for the purposeful formation of human capital, has the opportunity to steadily develop the Arctic and benefit from it. In connection with climatic, conjuncture and technological challenges, the Arctic zone of the Russian Federation will face serious challenges in the coming years. Responding to challenges of the XXI century, rapid and effective mobilization of scientific and technological initiatives accompanied with the search for talent and active entrepreneurs are required. Regional personnel initiative will raise the level of human capital, which is especially important in the Arctic zone of the Russian Federation. It should be noted that not a single Arctic region of Russia currently possesses technological capabilities, scientific and research potential, entrepreneurial initiative and finances necessary for a scientific and technological breakthrough. In rare cases some are able to offer sustainable, advanced and demanded scientific-technological and technical solutions. The proposed regional personnel initiative is aimed at outstripping the increase in the general (regional and attracted) intellectual potential that will ensure the development of Arctic ecosystem.
The detection of CA 125 protein in a solution using a silicon-on-insulator (SOI)-nanowire biosensor with n-type chip has been experimentally demonstrated. The surface of nanowires was modified by ...covalent immobilization of antibodies against CA 125 in order to provide the biospecificity of the target protein detection. We have demonstrated that the biosensor signal, which results from the biospecific interaction between CA 125 and the covalently immobilized antibodies, increases with the increase in the protein concentration. At that, the minimum concentration, at which the target protein was detectable with the SOI-nanowire biosensor, amounted to 1.5 × 10
M.
Abstract Heart failure (HF) claims 250,000 lives per year in the US, and nearly half of these deaths are sudden and presumably due to ventricular tachyarrhythmias. QT interval and action potential ...(AP) prolongation are hallmark proarrhythmic changes in the failing myocardium, which potentially result from alterations in repolarizing potassium currents. Thus, we aimed to examine whether decreased expression of the rapid delayed rectifier potassium current, IKr , contributes to repolarization abnormalities in human HF. To map functional IKr expression across the left ventricle (LV), we optically imaged coronary-perfused LV free wall from donor and end-stage failing human hearts. The LV wedge preparation was used to examine transmural AP durations at 80% repolarization (APD80), and treatment with the IKr -blocking drug, E-4031, was utilized to interrogate functional expression. We assessed the percent change in APD80 post-IKr blockade relative to baseline APD80 (∆APD80) and found that ∆APD80s are reduced in failing versus donor hearts in each transmural region, with 0.35-, 0.43-, and 0.41-fold reductions in endo-, mid-, and epicardium, respectively ( p = 0.008, 0.037, and 0.022). We then assessed hERG1 isoform gene and protein expression levels using qPCR and Western blot. While we did not observe differences in hERG1a or hERG1b gene expression between donor and failing hearts, we found a shift in the hERG1a:hERG1b isoform stoichiometry at the protein level. Computer simulations were then conducted to assess IKr block under E-4031 influence in failing and nonfailing conditions. Our results confirmed the experimental observations and E-4031-induced relative APD80 prolongation was greater in normal conditions than in failing conditions, provided that the cellular model of HF included a significant downregulation of IKr . In human HF, the response to IKr blockade is reduced, suggesting decreased functional IKr expression. This attenuated functional response is associated with altered hERG1a:hERG1b protein stoichiometry in the failing human LV, and failing cardiomyoctye simulations support the experimental findings. Thus, of IKr protein and functional expression may be important determinants of repolarization remodeling in the failing human LV.
Separation of mixtures in connected channels Glukhov, A. F.; Demin, V. A.; Putin, G. F.
Journal of applied mechanics and technical physics,
2009/1, Letnik:
50, Številka:
1
Journal Article
Recenzirano
The stationary modes of thermal convection of a binary mixture in connected channels of finite height were studied experimentally and theoretically. The effects of positive and negative thermal ...diffusion on the convection were examined. The ranges of parameters corresponding to the modes of soft and rigid initiation of convection were determined. Vertical distributions of the temperature and concentration fields were found for various values of the thermal diffusion parameter.
The paper presents a brief analytical review of the current state of research in the field of recovery and its modeling in order to predict the structure and properties, as well as a review of ...experimental research methods and mathematical models of the processes of structure formation during annealing of cold-rolled steels. The paper also presents the results of an experimental study of the recovery process in cold-rolled automotive steels using various techniques and describes a mathematical model for calculating the kinetics of this process depending on the temperature and chemical composition of steels.
The application of micro-Raman spectroscopy was used for characterization of structural features of the high-k stack (h-k) layer of “silicon-on-insulator” (SOI) nanowire (NW) chip (h-k-SOI-NW chip), ...including Al2O3 and HfO2 in various combinations after heat treatment from 425 to 1000 °C. After that, the NW structures h-k-SOI-NW chip was created using gas plasma etching optical lithography. The stability of the signals from the monocrine phase of HfO2 was shown. Significant differences were found in the elastic stresses of the silicon layers for very thick (>200 nm) Al2O3 layers. In the UV spectra of SOI layers of a silicon substrate with HfO2, shoulders in the Raman spectrum were observed at 480–490 cm−1 of single-phonon scattering. The h-k-SOI-NW chip created in this way has been used for the detection of DNA-oligonucleotide sequences (oDNA), that became a synthetic analog of circular RNA–circ-SHKBP1 associated with the development of glioma at a concentration of 1.1 × 10−16 M. The possibility of using such h-k-SOI NW chips for the detection of circ-SHKBP1 in blood plasma of patients diagnosed with neoplasm of uncertain nature of the brain and central nervous system was shown.
PDF
