10 research outputs found

    Detection of angiospastic disorders in the microcirculatory bed using laser diagnostics technologies

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    The evaluation of the microcirculatory bed functional state and the identification of angiospastic disorders with related complications, when the pathological changes are reversible, have an important role in medical practice. The aim of this study was to evaluate the possibility of using optical noninvasive methods and the cold pressor test to solve this problem. A total of 33 patients with rheumatological diseases and 32 healthy volunteers were included in the study. Laser Doppler flowmetry, tissue reflectance oximetry and pulse oximetry were used as optical noninvasive methods. The parameters were recorded before, immediately after and 20(Formula presented.)min after the cold pressor test. Based on the measured parameters, the complex parameters of the microcirculatory bed were calculated. A detailed statistical analysis of the parameter changes for each individual in the two groups displayed diverse microcirculatory bed parameter responses upon cold exposure, with differing recovery of parameters after CPT. New diagnostic criteria were proposed for the identification of angiospastic disorders. According to the proposed criteria, 27 people of the volunteers group were confirmed to not display any disorders. In the patient group, however, 18 people were observed to have a relatively normal functional state of the microcirculatory bed, while 15 people were observed to have a possible tendency to angiospasm. To highlight the differences between a relatively normal state and presence of angiospastic disorders, statistical analysis of experimental data was carried out, which revealed significant differences. Further analysis of data with angiospastic disorders identified a relationship between their diagnoses and the results of laboratory studies. Thus, the evaluation of combined noninvasive optical diagnostic method use, the cold pressor test and proposed diagnostic criteria showed a positive result. This approach can be used to detect the presence of possible angiospastic disorders and related complications, as well as microcirculatory bed disorders against the background of other diseases

    Automation of a dynamic system with computer simulation of heat losses

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    The article describes approaches to automation of a non-linear system, the stability of which essentially depends on the impact of external factors and requires compliance with high safety standards. The authors model the processes occurring in the system, substantiate the selection of the equipment. In the paper, the authors take into account (with accepted admissions) the heat losses in the pipes

    Automation of a dynamic system with computer simulation of heat losses

    No full text
    The article describes approaches to automation of a non-linear system, the stability of which essentially depends on the impact of external factors and requires compliance with high safety standards. The authors model the processes occurring in the system, substantiate the selection of the equipment. In the paper, the authors take into account (with accepted admissions) the heat losses in the pipes

    THE REACTIONS OF THE «BEAM – FOUNDATION» SYSTEM TO THE SUDDEN CHANGE OF THE BOUNDARY CONDITIONS

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    The authors constructed a mathematical model of a dynamic process in a loaded beam on the elastic Winkler foundation in a sudden formation of a defect in the form of a change in the boundary conditions. The solution of the static problem of bending of the beam pinched at the ends served as the initial condition for the process of forced vibrations hinged supported at the ends of a beam, which arose after a sudden break in the connections that prevented the rotation of the end sections. The authors determined the dynamic increments of stresses in a beam for various combinations of a beam and foundation parameters

    Ground geomagnetic field and GIC response to March 17, 2015, storm

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    Abstract The St. Patrick’s Day geomagnetic storm on March 17, 2015, has been chosen by the space community for synergetic analysis to build a more comprehensive picture of the storm’s origin and evolution. This storm had an unusually long (~ 17 h) main phase. During this period, many substorm-like activations occurred. These activations resulted in bursts of geomagnetically induced currents (GICs) in power lines on the Kola peninsula. To examine the substorm activations in more detail, we apply various data processing techniques for the world-wide array of magnetometers: the virtual magnetograms, magnetic latitude–local time (MLT) snapshots, and magnetic keograms. These techniques are simple tools that are supplementary to more advanced facilities developed for the analysis of SuperDARN, IMAGE, and CARISMA arrays. We compare the global spatial localization and time evolution of the geomagnetic X-component disturbance and magnetic field variability measured by the Hilbert transform of time derivative dB/dt. The latitude-MLT mapping of these magnitudes shows that very often a region with highest magnetic variability does not overlap with a substorm “epicenter” but is shifted to its poleward or equatorward boundaries. Highest variability of the geomagnetic field, and consequently intense GICs, are caused by medium-scale fast varying structures. There is no one-to-one correspondence between substorm intensity and GIC magnitude

    Monitoring of Geomagnetic and Telluric Field Disturbances in the Russian Arctic

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    The influence of space factors on technological systems in the Arctic (power transmission lines, oil/gas pipelines) has become critically important. To examine in depth these effects, an archive of digital 1 min data from Soviet/Russian magnetic stations deployed along the Arctic coast was created, starting from 1983 to the present. All data from various sources were converted to daily files in standard IAGA-2002 format and supplemented with quick-look magnetograms. Some of these data are included already in the existing world magnetic field databases, but not all. Examples of disturbances known to excite intense geomagnetically induced currents in power transmission lines were presented: irregular Pi3 pulsations and magnetic perturbation events. The database was augmented with the global 3D model of the Earth’s conductivity structure. The given example showed how the combined usage of the geomagnetic field database and the conductivity model enables one to synthesize the geoelectric field response to geomagnetic variations, and to assess the distortions of the pipeline-soil potential. To determine regions most susceptible to geomagnetic hazard, a map with normalized telluric fields was created for a uniform sinusoidally varying magnetic disturbance. This map showed that the largest electrotelluric potentials and field are induced in regions with a high resistivity (e.g., Kola Peninsula and Ural Mountains). This database can be also a useful support for space missions in the magnetosphere. The database is publicly available on the anonymous FTP site

    Comparative Efficiency of Removable Mini-Implant Retained Dentures Using Different Attachments in Edentulous Patients

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    Aim. To compare the efficiency of removable mini-implant retained dentures using different types of attachment.Materials and methods. The study included 51 edentulous patients. The patients were divided into three groups according to the attachment type and abutment shape: 1) ball-and-socket attachment, ball abutment (n = 26); 2) locator attachment, equator abutment, XiVE LOCATOR system (n = 14); 3) bar attachment (n = 11). Removable dentures were made of ordinary acrylic plastic. The placement of intraosseous dental implants with their sublingual engraftment was performed according to the traditional two-stage delayed-load procedure. The efficiency of implants was evaluated using the method of M.Z. Mirgazizov and the eponymous index. The dynamics of vertical bone resorption around implants was determined using dental panoramic radiography (6 months, 1 and 2 years after the treatment). A periotest was performed 6 months after the end of the orthopaedic treatment.Results. The one-year survival rate of implants reached 96.2% in group 1, amounting to 100% in groups 2 and 3. The two-year survival rate came to 92.3% in group 1, reaching 92.9% and 100% in groups 2 and 3, respectively. Inflammatory phenomena characteristic of peri-implantitis were noted one year after the implant placement in 7.7% (n = 2) of patients in group 1 and in 7.1% of patients in group 2, with no inflammatory phenomena being observed in group 3. Two years after the implant placement, peri-implantitis was observed in 19.2% and 21.4% of patients in groups 1 and 2, respectively, coming to 9.1% in group 3. The periotest revealed that six months after the placement, implant stability was higher in group 3 for both the lower and upper jaw (in comparison with groups 1 and 2), as evidenced by the shift in periotest values towards the negative part of the scale.Conclusion. The study revealed that bar attachment, as well as locator attachment (equator abutments), of removable dentures supported by mini implants is more efficient as compared to the ball-and-socket attachment
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