Биофизика
Reference:
Pashovkin T.N.
Frequency-dependent changes in the activity of blood enzymes under the action of modulated ultrasound.
// Physics of biology and medicine.
2024. № 1.
P. 1-23.
DOI: 10.7256/2730-0560.2024.1.44003 EDN: RCZRDR URL: https://en.nbpublish.com/library_read_article.php?id=44003
Abstract:
The subject of the study is frequency-dependent changes in the activity of blood enzymes of laboratory animals (rats) under the influence of modulated ultrasound of a therapeutic range of intensities. With equal-energy exposure to the enzyme systems under study, action spectra are shown for the following enzymes: creatine kinase, alkaline phosphatase, lactate dehydrogenase, aspartate aminotransferase, cholinesterase, indicating the possibility of frequency control of the functional state of enzymes, activation and inhibition of enzyme activity at frequencies specific for each enzyme. The activity of all enzymes is controlled in two ways: a) by changing the frequency of the influencing signal and b) by changing the energy (or amplitude) of the influencing signal at the biologically active frequency. Obtaining detailed action spectra is a necessary condition for developing the theoretical basis for determining biologically active frequencies and mechanisms of frequency-dependent responses of specific biological systems to external influences of modulated waves. The main conclusions of the study are: The main approach to studying modulated waves is to obtain and use action spectra for various biological systems. Using exposure at an active frequency, it is possible, by changing the energy of the impacting ultrasound, to obtain multidirectional effects. Thus, both the modulation frequency and the impact energy can be factors in controlling the functional state of enzyme systems using modulated ultrasonic waves. The purpose of the article is to show the presence of frequency-dependent responses of various enzyme systems when exposed to modulated ultrasonic waves of a therapeutic range of intensities - performed using the example of five enzyme systems. The action spectra for these systems and the possibility of transforming these spectra when changing the ultrasound intensity are presented. The possibility of controlling the magnitude and sign of the responses of the studied enzyme systems, both the modulation frequency and the energy of ultrasonic influence, has been demonstrated.
Keywords:
cholinesterase, aspartate aminotransferase, lactate dehydrogenase, alkaline phosphatase, creatine kinase, modulation frequency, blood enzymes, enzyme activity, modulation, ultrasound
Биофизика
Reference:
Sarimov R.M.
The effect of hypomagnetic conditions on the size of a person's pupil
// Physics of biology and medicine.
2024. № 1.
P. 24-40.
DOI: 10.7256/2730-0560.2024.1.43854 EDN: RDFYOU URL: https://en.nbpublish.com/library_read_article.php?id=43854
Abstract:
Earlier it was reported that hypomagnetic conditions resulting from a 100-fold decrease in geomagnetic field induction affect human cognitive processes, which was evaluated in several computer tests. Exposure in hypomagnetic conditions for 40 minutes led to a statistically significant increase in both the execution time and the number of errors in the tasks. The magnitude of this magnetic effect, averaged over 40 healthy subjects in 80 hour experiments, was about 1.7 percent. This paper describes the results of a study in which the characteristics of the state of the right eye of each subject were recorded on video, while the subject performed cognitive tests. It turned out that under hypomagnetic conditions, the pupil size increases. This effect was calculated based on the processing of a large array of data, including more than a million video frames. The average magnetic effect was about 1.6 percent. Taking into account the heterogeneity, the significance level of the effect is close to significant (0.07, ANOVA, the subjects' factor is random). Magnetic reactions recorded both for different cognitive tests and for pupil size observed simultaneously do not correlate. Approximately equal numbers of testers showed positive and negative effects in each test. Non-specific reactions to the magnetic field appear to be random.
Keywords:
non-specific magnetic effect, color perception test, Shepard test, Stroop test, reaction rate test, magnetic fields, human magnetic response, eye pupil size, hypomagnetic conditions, biological effects
Биофизика
Reference:
Pashovkin T.N., Sadikova D.G.
Effect of continuous and modulated ultrasound on fish neurons.
// Physics of biology and medicine.
2024. № 1.
P. 41-54.
DOI: 10.7256/2730-0560.2024.1.71004 EDN: QYEYTI URL: https://en.nbpublish.com/library_read_article.php?id=71004
Abstract:
Currently, transcranial ultrasound stimulation (TUS) is being intensively developed as a new non-invasive method of neuromodulation. A convenient model for demonstrating ultrasonic neuromodulation is the nervous system of fish. Experiments have been carried out on Goldfishes. We have recorded general swimming reaction and turning reaction of fishes in the special chamber which bottom had been divided into sectors. We observed decrease of general swimming reaction and turning reaction after influence of continuous ultrasonic waves of therapeutic intensities (f = 0.88 MHz), when intensity was more than 0.7 W/cm2, and increase of these responses at intensities less than 0.1 W/cm2. Application of modulated ultrasonic fields as an acting factor produced changes of activity of fishes dependent on a modulating frequency. The action spectra have been received using an amplitude modulation (AM) of low frequency. This spectra reflect the work of the whole brain (tests of change of a general swimming reaction of fishes), and the work of identified Mauthner’s neuron, that is responsible for turning response of fishes. The action spectrum for Mauthner’s neuron is more expressed and contains three kinds of frequencies by the action on fishes activity: frequency of activation (8 Hz), partially depressing (6, 10 Hz) and neutral (3, 7, 9 Hz). Spectra are received at equienergy action АМ of ultrasonic sound irrespective of a modulating frequency (porosity = 2) and spatial average and temporal average intensities of 0.35 W/cm2. From an action spectrum we can conclude, that on one modulating frequency effects of a carrier frequency are relaxed, and on others strengthen. This approach can find application in ultrasonic therapy when it is necessary to make ultrasonic action more effective and to decrease potential hazard of action due to the cavity action.
Keywords:
activation, turning response, motor activity, frequency modulation, neuromodulation, Mauthner neuron, action spectrum, modulation, ultrasound, suppression
Медицинская физика
Reference:
Ermolaev E.S., D'yachenko A.I., Shulagin Y.A.
Simulation of human breathing gas exchange for the ventilation regulation study
// Physics of biology and medicine.
2024. № 1.
P. 55-76.
DOI: 10.7256/2730-0560.2024.1.69226 EDN: REVVJU URL: https://en.nbpublish.com/library_read_article.php?id=69226
Abstract:
The chemoreflex control of breathing plays a major role in human lung ventilation adjustment in response to metabolic demands and CO2, O2 partial pressure changes in the inhaled air. The extreme conditions, e.g. emergency work in mines or deep-sea diving, space flights, can change the respiratory system reaction to CO2 and O2. The study of the relevant respiratory system characteristics is an important fundamental and practical task. One of the convenient ways of research is mathematical simulation, which allows to reduce the number of experiments in extreme conditions or experiments for the personal protective equipment testing, as well as to forecast the estimated time of effective human work in such conditions. The model describes the dynamics of the gas content in the 3 compartments of the biological system and the external environment represented by the 4th compartment. The external environment can be limited by the volume of the device to which a person is connected, or by the volume of a closed hermetic object, or represented by a sufficiently large volume, conditionally being an atmosphere with appropriate parameters. A mathematical model of the breathing gas exchange with the external environment (the atmosphere or any other limited space) is presented. It is the first time, the simulation results of breathing at rest, during hyperventilation and rebreathing tests are presented, including gas dynamics in the pulmonary and tissue compartments, as well as in the brain compartment. Hypercapnia ventilation reaction during rebreathing tests with a hyperoxic - hypercapnic gas mixtures and different rebreathing bags in comparison with stationary methods of breathing control study. Verification of the model by simulation results with the literature data comparison showed the simulation model’s adequacy. A sensitivity table of the simulation model behavior in response to parameters changes is presented.
Keywords:
breathing under loading stress, respiration during rest, carbon dioxide, oxygen, rebreathing, mathematical simulation, gas exchange, atmosphere, human physiology, differential equations
Медицинская физика
Reference:
Kaspranski R.R., Binhi V.N., Koshel I.V.
Is the weakening of the magnetic field in space associated with the risk of errors in the activities of astronauts?
// Physics of biology and medicine.
2024. № 1.
P. 77-90.
DOI: 10.7256/2730-0560.2024.1.71398 EDN: RNPMPV URL: https://en.nbpublish.com/library_read_article.php?id=71398
Abstract:
The number of biomedical studies where the observed effects are determined by the laws of quantum physics is constantly growing. These include respiration, vision, smell, photosynthesis, mutations, etc., united by name "quantum biology". The effect on organisms of magnetic fields, including those weakened in comparison with the geomagnetic field, is one of such studies. The magnetic field can act only on magnetic moments, the most important representative of which is the electron. The magnetic field changes the quantum dynamics of electrons in the body, which ultimately leads to the observed reactions at the biochemical and behavioral levels. Organisms on Earth have evolved in a geomagnetic field, which means that its absence can cause disturbances in the normal functioning of organisms. Indeed, there are more than two hundred scientific publications on this topic. Today, it has been reliably established that the hypomagnetic field can change the functioning of organisms from bacteria and fungi to mammals and humans. In deep space flight and in future missions to the Moon and Mars, astronauts will be in a hypomagnetic field, which is less than a natural geomagnetic field by more than a hundred times. Such a weakening of the magnetic field is associated with an additional risk. This mini review provides initial information about the levels of the magnetic field on Earth, in near and distant outer space, and on the surfaces of the Moon and Mars. Information is provided on the hypomagnetic field effects on the human body and about the mechanisms of such effects. It is reported about the features of research in magnetobiology that require special statistical methods for processing the results. The complexity of creating a hypomagnetic field in volumes sufficient to accommodate the human body is discussed. The primary tasks in this relatively new research field are formulated.
Keywords:
animal magnetic navigation, radical pair mechanism, magnetobiology, organism, cosmos, interplanetary magnetic field, hypomagnetic field, geomagnetic field, human, magnetic biological effects