A Method of Microwave Radiothermometry in Studies of Circadian Rhythms of Brain Temperature.

We studied the possibility of using microwave radiothermometry of the brain in biorhythmology. It was found that the temperature variability of the frontal lobes of the right and left hemispheres strictly corresponded to the 24-h cycle was characterized by the oscillation amplitude of 1.2-1.4°C, which significantly exceeded the amplitude of the basal temperature. A conclusion was made about the informative value of the method of noninvasive registration of the 24-h dynamics of the brain temperature.

[Monitoring of brightness temperature fluctuation of water in SHF range].

The purpose of the research consisted in detection of fluctuation of brightness temperature (TSHF) of water in the area of the temperature Т = 42°Ð¡ (that is critical for human) during its evaporation by SHF radiometry. Methods: Monitoring of the changes in brightness temperature of water in superhigh frequency (SHF) range (3.8-4.2 GHz) near the phase transition temperature of water Т = 42°Ð¡ during its evaporation in the cone dielectric cell. The brightness temperature measurements were carried out using radiometer. Results: Fluctuation with maximum of brightness temperature was detected in 3.8-4.2 GHz frequency range near at the temperature of water Т = 42°Ð¡. It was characteristic for these TSHF fluctuations that brightness temperature rise time in this range of frequencies in ~4°Ð¡ temperature range with 0.05-15°Ð¡/min gradient and a sharp decrease during 10 s connected with measuring vapor conditions. Then nonintensive fluctuation series was observed. At that, the environment temperature remained constant. Conclusion: The significant increasing in brightness temperature of water during its evaporation in SHF range near the temperature of Т ~42°Ð¡ were detected. It was shown that for water, ТSHF pull with the amplitude DТSHF ~4°C are observed. At the same time, thermodynamic temperature virtually does not change. The observed effects can be used in the development of the systems for diadnostics of pathologies in human and analytical system.

SHF radiation from albumin solution upon external excitation.

The purpose of the research consisted in the measurement of nonequilibrium radiation in superhigh frequency (SHF) range from aqueous solution of albumin upon its mechanical stimulation. Methods: the monitoring of change in the ratio between brightness temperatures TSHF and TIR values after the mechanical stimulation of aqueous solution of albumin in the measuring cell at 35-39°Ð¡. The measurements of brightness temperatures were carried out with use of radiothermometer. SHF frequency range corresponded to 3.4-4.2 GHz, SHF frequency range corresponded to 8-13 mm. Results: It was found that mechanical stimulation of aqueous solution of albumin at the temperature ~39°Ð¡, the change in the ratio between TSHF and TIR occurs. This corresponds to emergence of nonequilibrium SHF radiation from the solution near the phase transition with ~39°Ð¡ temperature. Conclusion: The effect of emergence of nonequilibrium SHF radiation from protein solution near its temperature 39°Ð¡ was found. This temperature corresponds to the temperature of human organism upon a number of pathological states connected with inflammatory processes. The discovered effect can be used in the development of novel non-invasive methods of disease diagnostics.

Monitoring of brightness temperature of suspension of follicular thyroid carcinoma cells in SHF range by radiothermometry.

The purpose: The purpose of this research consisted in monitoring of brightness temperature of the suspension of follicular thyroid carcinoma cells during the necrosis of these cells in superhigh frequency (SHF) range. Methods: The monitoring of the change in the ratio between brightness temperatures TSHF and TIR values during the necrosis of these cells. The object of study was follicular thyroid carcinoma cells suspension prepared with use of Versene solution and 0.25% trypsin solution. The cells were precipitated by centrifugation and re-suspended in culture medium. The measurements of brightness temperatures were carried out with use of radiothermoimeter. SHF range was 3.4-4.2 GHz, and infrared (IR) range was 8-13 mm. The temperature of the suspension was maintained at 37.5°Ð¡. Results: It was found that upon the necrosis in the suspension of cells, an increase in brightness temperature in 3.4-4.2 GHz range (SHF range) occurs, while brightness temperature of the medium in the IR range does not change. Conclusion: The monitoring of necrosis of follicular thyroid carcinoma cells was carried out by SHF-radiothermometry. It was shown that during the necrosis the change of non-equilibrium state of cell medium occurs, that results in the change in the ratio between TSHF and TIR. During the necrosis, the brightness temperature in SHF range (TSHF) increases.

[Microwave emission from water in bioanalytical systems].

Mechanical stimulation of aqueous protein solution was found to be accompanied by electromagnetic radiation in the superhigh frequency range. This radiation was observed at solution temperatures near the phase transitions of water. This effect may occur in various bioanalytical systems, associated with injection of aqueous solutions in these systems, and may have impact on the results of bioalytical measurements. The discovered effect of generation of nonequilibrium microwave emission of water medium (which is the main component of the organism) in the 38-39°C temperature range, i.e. in the range of elevated temperature of the organism (which accompanies pathological condition in humans upon inflammatory diseases, i.e., infactious etc.) may be used for development of new non-invasive methods of disease diagnostics.

Medical Antennas for Microwave Radiothermometry of Biological Objects.

The results of an analytical review of various antennas used in medicine are presented. Issues of modern microwave radiothermometry related to the development of new antennas are discussed, as well as possible ways to solve them. The tasks of further research aimed at creating new designs for conformal antennas and antenna arrays providing a significant expansion of the functionality and improvements in the characteristics of medical radiothermographs are formulated. The study was supported by the Russian Science Foundation (Grant No. 22-19-00113), https://rscf.ru/project/22-19-00113/.

Some Methods for Substantiating Diagnostic Decisions Made Using Machine Learning Algorithms.

Various classification algorithms used in the diagnosis of breast cancer based on microwave radiometry data are considered. In particular, their principles of operation and the possibility of substantiating diagnoses using numerical data are discussed. A substantiation algorithm based on decision trees and a naive Bayesian classifier is presented. Examples of substantiation are given for breast cancer.

Microminiaturization of Multichannel Multifrequency Radiographs.

Due to the COVID-19 epidemic, the challenge of introducing methods for investigating patients reducing or eliminating the probability of infection of medical staff is currently relevant. This article provides an analytical review of new technological approaches to organizing the work of medical personnel in carrying out auscultation of patients with COVID-19. The development and approval of such technologies is shown to have started around the world. The ubiquitous and large-scale introduction of these methods into medical practice therefore seems expedient.

[Radiothermometry in diagnosis of thyroid diseases].

Primary experience (177 patients) of diagnosis of thyroid gland diseases with radiothermography using microwave radiothermometer RTM-01-RES is analyzed. In unaffected thyroid gland there were no temperature differences between symmetric points of right and left lobe. Cancer of thyroid gland and toxic adenoma are characterized by higher internal temperature. High sensitivity of method and its simplicity are the reasons for use of radiothermography as screening method.

Detection of microwave radiation of cytochrome CYP102 A1 solution during the enzyme reaction.

Microwave radiation at 3.4-4.2 GHz frequency of the cytochrome P450 CYP102 A1 (BM3) solution was registered during the lauric acid hydroxylation reaction. The microwave radiation generation was shown to occur following the addition of electron donor NADPH to a system containing an enzyme and a substrate. The radiation occurs for the enzyme solutions with enzyme concentrations of 10-8 and 10-9 Ðœ. The microwave radiation effect elicited by the aqueous enzyme solution was observed for the first time. The results obtained can be used to elaborate a new approach to enzyme systems research, including studying of the mechanism of interaction of a functioning enzyme system with microenvironment.

Monitoring of microwave emission of HRP system during the enzyme functioning.

Monitoring of microwave emission from aqueous solution of horseradish peroxidase (HRP) in the process of the enzyme functioning was carried out. For the monitoring, a system containing HRP, luminol and Н2О2 was employed. Microwave emission measurements were carried out in the 3.4-4.2 GHz frequency range using the active and passive modes (active-mode and passive-mode measurements). In the active mode, excitation of the solution in the pulsed electromagnetic field was accomplished. In the passive mode, no excitation was induced. It appears that the passive-mode measurements taken in the course of the peroxidase reaction in the enzyme system have shown a 0.5 °Ð¡ increase of the microwave signal. Upon the active-mode measurements, taken in the same reaction conditions, the forced excitation of the solution has also led to the increase (by 2 °Ð¡) of the level of the microwave signal - i.e. to its 4-fold enhancement compared to the signal obtained in passive-mode measurements.

[AFM fishing of proteins under impulse electric field]. / ASM-fishing belka v impul'snom élektricheskom pole.

A combination of (atomic force microscopy)-based fishing (AFM-fishing) and mass spectrometry allows to capture protein molecules from solutions, concentrate and visualize them on an atomically flat surface of the AFM chip and identify by subsequent mass spectrometric analysis. In order to increase the AFM-fishing efficiency we have applied pulsed voltage with the rise time of the front of about 1 ns to the AFM chip. The AFM-chip was made using a conductive material, highly oriented pyrolytic graphite (HOPG). The increased efficiency of AFM-fishing has been demonstrated using detection of cytochrome b5 protein. Selection of the stimulating pulse with a rise time of 1 ns, corresponding to the GHz frequency range, by the effect of intrinsic emission from water observed in this frequency range during water injection into the cell.