Search

Results are presented from research to determine dependences of characteristics of dose distributions in biological objects on their thickness and density, and the energy of electron beams used in the radiation processing of food products.

A series of comprehensive studies is performed to optimize the use of radiation technologies in the sterilization and processing of biological objects. Experimental study reveals the nonlinear dependence of the effectiveness of suppressing pathogenic microorganisms on samples of chilled turkey meat on the dose rate with the doses ranging from 0.25 to 6 kGy. Fluorescence fingerprinting reveals no appreciable differences between irradiated and non-irradiated samples.

Ways of making precise magnetic measurements and the corresponding magnetometric equipment are promising for practical use in studying electromagnetic processes that occur in biological objects. Analysis of the magnetic component of the electromagnetic activity of different human organs using superconducting quantum magnetometers can be used to develop new medical technologies for the early diagnosis and effective treatment of cardiovascular, oncological, and other major diseases.

The huge space of experimental data on biological and chemical objects and their interactions contributes to the rapid growth of scientific publications containing their analysis. Such data may include characteristics of low-molecular-weight compounds, results of their biological activity evaluation, and their interaction with human and animal proteins, methods of synthesis of organic compounds, and their classification. The past decades saw the development of methods for automated extraction of data from texts of scientific publications, including those for retrieval of names of organic compounds. These data can be used for the automatic identification of the names of organic compounds, including all possible synonyms. Since the topics of scientific publications are diverse, the extracted data can be applied to obtain information about (1) classification of organic compounds (2) methods of synthesis of a given organic compound; (3) physicochemical properties of this compound; (4) its interaction with high-molecular-weight compounds (including proteins, mRNA of animals and humans); and (5) the therapeutic properties of organic compounds, the active substance of the drug, and data on clinical trials. This review considers the methods aimed at searching and extracting data on names of low-molecular-weight compounds and interactions between them and animal and human proteins (biological objects), as well as data on experimentally confirmed biological activity and the effects of organic compounds (including drugs) on pathological processes. Here, we discuss the methods developed and the results of their application published over the past 10 years.

Formalized approach to the analysis of biomedical signals and images with locally concentrated features is developed on the basis of matched morphological filtering taking into account the useful signal models that allowed generalizing the existing methods of digital processing and analysis of biomedical signals and images with locally concentrated features. The proposed matched morphological filter has been adapted to solve such problems as localization of the searched structural elements on biomedical signals with locally concentrated features, estimation of the irregular background aimed at the visualization quality improving of biological objects on X-ray biomedical images, pathologic structures selection on mammogram. The efficiency of the proposed methods of matched morphological filtration of biomedical signals and images with locally concentrated features is proved by experiments.

To substantiate the quantitative values of the process of destruction of weeds by means of electric impulse and to elucidate the mechanism of damage and the sequence of disturbances that occur in the internal structure of the processed plants, it is necessary to know not only the design of the electrical circuit of the plant tissue substitution but also to have information on the nature of the change in the parameters of the elements of this scheme during electric damage. The presented technique allows (with the help of inexpensive and accessible technical means) to control the damage to the tissues of a weed plant and to calculate quantitative values using developed mathematical apparatus. The analysis shows that the damage to weed plant tissues can be characterized, first of all, by the loss of cell membranes in their semipermeable functions and an increase in the active conductivity of the processed areas of plants. Such changes in the internal structure of plant tissue lead to loss of cell viability in the areas subjected to the electric impulse treatment. The presented analysis fits the current thinking of biophysicists on the electrical damage to the internal structure of biological objects. The technological studies of the process of the electric impulse irreversible damage to plant tissues conducted, based on the analysis presented in the article, allow us to limit the supplied electric energy that makes it possible to make electric impulse weeding an energy-saving means of combating weeds.

The biological activity of laser radiation (wavelength, 632.8 nm) when it interacts with human serum albumin is demonstrated. The most noticeable effect of exposure to laser radiation is observed when the energy density is 28.8 J cm−2. It is assumed that three-photon absorption is the main mechanism of biological stimulation.

Experimental studies on the radiation treatment of food products by various types of ionizing radiation are conducted at Moscow State University’s Faculty of Physics. The effect different doses of X-ray radiation have on the biochemical characteristics of potatoes is considered as an alternative to gamma radiation and accelerated electrons. The effect different doses of accelerated electrons have on the microbiological parameters of refrigerated fish products is also considered. Results are presented from studies on the radiation sterilization of bioimplants in combination with chemical action. The proposed technique of combined sterilization based on the effect of an ozone–oxygen mixture and a beam of accelerated electrons allows the radiation dose of bioimplants to be reduced.

The cumulative applied climate indices SAT and SET used in the Russian literature are considered in detail. These indices differ in calculation methods and, consequently, their values differ in different regions. The example is presented of the incorrect use of these indices by some authors for studying biological objects which leads to false conclusions. The method of calculation of the foreign applied climate index GDD is given. This index corresponds to the Russian index SET, and its interpretation as a counterpart of SAT is wrong.

Visible light is a necessary condition for the existence of life on the Earth. The food and oxygen consumed by humans, directly or mediately, are products of photosynthesis: conversion of light energy into the energy of chemical bonding in organic matter. Visible light not only provides photosynthesis in plants; it is also involved in the regulation of many reactions (from molecular to behavioral) in the animal world. This review is devoted to the questions concerning the role of light in the life of biological objects and the physical mechanisms of interaction of visible light with matter. The effect of light on the molecular and physiological reactions of a human and its microflora is analyzed. The existing methods and the application potential of light effects in diagnostics and therapy are considered.

The possibility of application of the vibrational and acoustic SFCO sensors for investigation of biomedical signals is discussed. The applicability of such sensors to register the muscle activity of vocalization apparatus of larynx and the prospect of their use for the research of the cardiovascular system are demonstrated. The physical principles and advantages of the SFCO sensors in biomedical investigations are also discussed.

The problem of digital holographic imaging of optically transparent objects in arbitrary spectral intervals is discussed. An optical scheme based on Mach−Zehnder interferometer with acousto-optic filtration of broadband light is proposed, and an experimental setup is described. Digital holograms of test patterns and real biological objects are presented.

A problem of tracking of a group of identical objects with a variable shape and a large number of occlusions is considered. This problem is important for biology and safety systems. An algorithm of detection and tracking of biological objects on the basis of a sequence of depth images is proposed. Being tested, the algorithm provides one mistake per 193 collisions for the worst sequence.

The article presents the main features of magnetothermia influence on biological objects including the characteristics of magnetic antenna near-field, the changes of blood flow and of diffusion, which are caused by the temperature and by the magnetic field.

In this paper, the results of application of artificial neural networks for extraction of fluorescence contribution of nanoparticles used in biomedicine as biomarkers and drug carriers against the fluorescence background of inherent fluorophores of biological objects are presented. Principle possibility of solving this problem is shown. The used architectures of ANN allow detecting fluorescence of carbon dots against the background of proper fluorescence of egg protein with reasonably high accuracy-not worse than 0.002 mg/mL.

Results of numerical 2D and 3D-simulations of the performance of nanowire sensors on the basis of silicon-on-insulator structures aimed at determining the optimum conditions for the response to dielectric particles, are given. The effect of screening of nanowires by dielectric particles in solutions with pH = 7 used as a medium for transporting biological objects is considered.

A new approach to analyzing the data obtained by tracking biological objects in studying the motion activity is considered. The approach is based on a proposed mathematical model of motion of a biological object. The object behavior observed during the experiment can be described in the form of model parameters. A numerical experiment with model data is performed, which shows that the estimates predicted by the proposed method ensure a smaller root-mean-square deviation of the object state classification than other available methods.

Processes in the human-woven heater-thermally insulating layers of a belt with electric heating-environment system are considered. The temperature distribution in the system with contact heating for switched-off and switched-on heaters is described. The reaction of the system on switching on the heater that was obtained experimentally using woven heaters is shown. The results of the study can be used in the development of a wide range of products providing contact heating of biological objects.

Achievements in the area of research into the micromanipulation of objects within the micron range are considered. The similarities and differences between objects in the macro-and micromanipulation area are discussed. The author describes the adhesive mechanisms that act in the microworld in adhesion to hard surfaces in the presence of liquid adhesives and without their participation. Theoretical models are presented for estimating the adhesion forces arising between micro-objects and the area of micromanipulation, as well as some practical experiments with mechanical and biological objects in regard to their grasping and clinging to surfaces.

This paper describes the properties of using digital and computer equipment in order to collect and store the characteristics of biological material. Using the example of different development stages in the carp, the method for measurements and morphotype description is shown.