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The article is devoted to the consideration of “digitalization” concept as a tool for solving control problems. The problems of digital twins formation are discussed and two directions for digital models creation are presented. The necessity of using a natural-model approach, methods of natural-mathematical modeling, similarity theory for building digital models is noted.

The article is devoted to the specific character of using digital twin technology in the coal industry. The key points and nuances of this technology application in the industry in general and in the coal industry in particular are discussed.

Muon radiography is a method of study the internal structure of large natural and industrial objects based on sensing an object with a flux of cosmic muons with their subsequent registration and analysis of the pattern of their dispersion, or conplete (or partial) absorption. The Lebedev Physical Institute of the Russian Academy of Sciences and the Skobeltsyn Institute of Nuclear Physics of Moscow State University have started a series of muon radiography experiments with nuclear emulsion detectors. As a result, the optimal conditions for experiment arrangement have been determined, algorithms of data processing have been worked out, and peculiarities of the method have been ultimately investigated.

Objectives: To compare the accuracy of cone-beam CT ex vivo and in vivo for the detection of artificially created large and small vertical root fractures in extracted teeth restored with post-core., Methods: Individual metal cast post-cores were fixed in the root canals of 50 extracted single-rooted human teeth. In 30 teeth fractures were created by tapping posts with a hammer. The teeth were sterilised in autoclave and embedded into bite-plates made of silicon impression material. Cone-beam CT scanning was performed ex vivo and in vivo . For the in vivo scanning, teeth in sterile plastic bags were inserted into the mouths of volunteers. Then the teeth were sectioned with low-speed saw and the widths of the VRFs were measured microscopically. The teeth were distributed into 2 groups in accordance with the measured fractures' widths: large (wider than 180-250 µm) and small (80-150 µm). Five observers assessed the presence of vertical root fractures on axial CBCT slices. Sensitivity, specificity, accuracy and inter examiner agreement were calculated., Results: The accuracy of cone-beam CT in vitro for large and small vertical root fractures detection was 0.56 and 0.40 respectively ( p = 0.043). The sensitivity values were 0.53 and 0.27 for large and small vertical root fractures, respectively ( p = 0.043). The visualisation of fracture lines in vivo was impossible in 90 % of cases, because of low image quality. Inter examiner reliability analysis showed κ values ranging from 0.02 to 0.54., Conclusions: Fracture width affected the in vitro detectability of vertical root fractures by cone-beam CT in teeth with metal cast post-cores. The detectability of root fractures in vivo was decreased because of low image quality, making the assessment of sound tooth tissue impossible.

Aim: To compare the in vivo accuracy of CBCT for the detection of fracture lines versus the diagnosis of vertical root fractures (VRFs) according to characteristic patterns of associated bone resorption., Methodology: Eighty-eight patients with symptoms typical of VRFs in root filled teeth, who underwent a CBCT examination and later had the teeth extracted, were divided into two groups: the fracture group (n = 65) and the control group (n = 23). Five blinded observers assessed the CBCT images in two sessions. During the first session, they were asked to state the diagnosis according to the CBCT and clinical data. During the second session after 2 weeks, they assessed only axial slices and were asked to detect a fracture line. The mean CBCT specificity, sensitivity, accuracy values and area under the receiver operating characteristic (AUROC) curve were calculated and compared using the Wilcoxon signed-rank test., Results: The average sensitivity of CBCT for the diagnosis of VRFs was 0.84 ± 0.2. The accuracy and AUC values were 0.81 ± 0.08 and 0.84 ± 0.17, respectively. The sensitivity, accuracy and AUC values for the detection of VRFs were significantly lower: 0.17 ± 0.24 (P = 0.042), 0.54 ± 0.07 (P = 0.043), and 0.52 ± 0.09 (P = 0.043), respectively. The specificity of CBCT for the detection and diagnosis of VRFs did not differ significantly (P = 0.50)., Conclusion: Cone-beam computed tomography was helpful in VRF diagnosis even when it was not possible to visualize the fracture line., (© 2019 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

Aim: Compare clinical and radiological features of keratinized gingiva and buccal cortical bone of identical corresponding contralateral teeth with recession (recession group) or without recession (control group). A total of 60 teeth from 27 patient were observed. The thickness of gingiva was significant reduced in recession group (0.85 mm, range 0.7-0.95 mm) that in control group (0,95 mm, range 0.8-1.0 mm), p<0.05. In recession and control group the height of keratinized gingiva was 1.58 mm (range 0.9-1.9 mm) and 3.0 mm (range 2-3.4 mm), correspondingly (p<0,05). The mean distance from cementoenamel junction to buccal cortical bone was strongly different in recession and control group (5,8 mm vs 4,47 mm, p<0.05).

Aims: To compare the diagnostic accuracy of cone beam computed tomography (CBCT) for the detection of artificially induced vertical root fractures (VRFs) of different widths in vitro and in vivo., Methodology: Vertical root fractures were induced in 25 extracted nonendodontically treated single-rooted human teeth (maxillary first premolars, maxillary canines and mandibular incisors). Twenty teeth without VRFs served as a control group. CBCT scanning (3D Accuitomo 170) was performed in vitro and in vivo. For the in vivo scanning, teeth were autoclaved, embedded into bite plates, placed in sterile plastic bags and then inserted into the mouths of volunteers. Teeth with VRFs were sectioned into axial slices and examined using a stereomicroscope to measure the widths of the VRFs. Five observers assessed the presence of VRFs using axial CBCT. Values for sensitivity, specificity, accuracy and interexaminer agreement were calculated., Results: The accuracy, specificity and sensitivity of CBCT were significantly higher in vitro than in vivo for VRFs with widths 50-150 μm (P < 0.05). The sensitivity and accuracy of CBCT were significantly higher for the detection of VRFs with widths greater than 150 μm in vivo and in vitro (P < 0.05). The accuracy of CBCT in vivo was 0.29 and 0.8 for fracture widths ranging from 50 to 150 μm and wider than 150 μm, respectively. No significant differences in CBCT specificity were found between VRF widths both in vitro and in vivo. The interexaminer reliability of the raters revealed a kappa value of 0.72, demonstrating substantial agreement., Conclusion: The detectability of VRFs by CBCT in vitro and in vivo was dependent upon fracture width. The accuracy of CBCT in detecting VRFs of 50-300 μm width in vivo was significantly lower compared to the in vitro accuracy., (© 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

The aim of the study was to assess the feasibility and precision of vertical root fracture diagnostics by cone beam CT (CBCT). Vertical root fractures were simulated in 25 sound teeth extracted because of orthodontic and periodontal reasons and examined by CBCT. The roots were then sectioned in corresponding planes and fractures were assessed microscopically. CBCT sensitivity and precision was significantly higher for visualization of vertical fractures >150 µm when compares to fractures <50 µm with no difference in specificity. CBCT is an effective tool for vertical root fractures detection.

A series of investigations have demonstrated the anti-inflammatory, bactericidal, analgesic, and vegetocorrective effects of extraocular selective polarized chromotherapy using blue and red light and the possibility to optimize autonomous regulation with the help of this technique. The results of the study confirmed the high clinical effectiveness and safety of the method being considered for the treatment of acute respiratory diseases, chronic tonsillitis, cervical dorsopathies, and vegetative dysfunction.

It is inferred from analysis of normal physiology data that erythrocyte membrane permeability for the oxygen in human organism must decrease at least 1000 times after oxygenation in the lungs. And the cell membranes of other tissues are also capable to change their permeability for the oxygen. The kinetics of blood oxygenation and deoxygenation is investigated in order to check this conclusion. Measurements of blood oxygenation kinetics together with oxygen tension in blood plasma allows to determine average value of membrane permeability decrease being equal 70 times. Biological expediency of fluctuation of the erythrocyte membrane permeability is discussed. A method of determination of optical oxymeters calibration and hemoglobin-oxygen equilibrium curve for the blood is proposed. It does not require the oxygen equilibrium between the blood plasma and the erythrocyte cytoplasm and uses only readings of a calibrated oxymeter. Variation of non-equilibrial state of the erythrocyte during the oxygen saturation is considered as the cause of the membrane permeability fluctuation. Erythrocyte parameters, such as its volume, substances concentration, transmembrane potential, are shown to depend on the amount of the substances not penetrating through the membrane and on osmotic pressure. A hypothesis of the transmembrane potential influence on the membrane permeability is proposed. The external electric field is shown experimentally to accelerate the blood deoxygenation.

The process of blood oxygenation in vitro was described theoretically. It was established that the dynamics of the oxygenation degree of different blood samples can be obtained from the certain universal time function by a change of the time scale. A special device was created for experimental investigation of oxygenation dynamics. The experimental data are in agreement with the theory.