Introduction. Liquid respiration is the ability of mammalian lungs to receive oxygen dissolved in a liquid for respiration and release carbon dioxide into it. A promising field of application is the provision of marine operations. For the use of liquid respiration during deep-sea operations, the technology must ensure the normal functioning of all organs and systems of the body, prevent decompression sickness, and allow conscious activity.

The study aims to assess the safety of conditioned reflex activity during independent liquid respiration in laboratory animals in normobaric conditions.

Materials and methods. We performed the study on male Syrian hamsters aged four months, weighing 120-140 g. Researchers have developed a stand with an eight-level maze with a lock. We immersed the labyrinth in an aquarium. The scientists carried out the study in two stages. At the first stage, we have developed in animals a conditioned reflex of actively avoiding drowning in conditions of breathing air. The researchers placed the animal on the lower level, then immersed the maze in an aquarium filled with water at a speed that only the animal's head was above the water level. The threat of drowning prompted the animal to search for a passage to a higher level. The training was three times a day for ten days. At the second stage, scientists studied the influence of various conditions of liquid respiration on the state of the conditioned reflex activity of animals. We used two respiratory fluids — perfluorohexane (PFH) and perfluorodecalin (PFD) in three temperature regimes: 22.0, 27.0, and 32.0°C. The researchers filled the aquarium with two oxygenated respiratory fluids of the required temperature instead of water. We have entirely immersed the maze with the animal fixed at the lower level in the aquarium. After switching to liquid respiration, scientists removed the animal from fixation. From the moment of removal from fixation, the countdown of the passage of the maze began. First, we assessed the condition of conditioned reflex activity by the number of animals in the group that successfully passed the maze and the average time of its passage.

Results. Animals on liquid respiration in perfluorohexane successfully passed the labyrinth in all temperature conditions. The average transit time at 22.0°C was 323±94 s; 27.0°C — 45±12 s; 32.0°C — 147±101 s. Animals on liquid respiration in perfluorodecalin successfully passed the labyrinth at a temperature of 27.0°C; the average passage time is 131±79 s; at a temperature of 32.0°C, 20% of animals successfully passed the labyrinth, the average time is 32.5 s; at a temperature of 22.0°C, none of the animals passed the maze.

Conclusions. Conditioned reflex activity during independent liquid respiration in small laboratory animals in normobaric conditions persists and depends on the physico-chemical properties and temperature of the respiratory fluid.

Introduction. The workers of coal mines are characterized by a high level of not only occupational diseases, but also oncological diseases. Modern knowledge in the field of studying pneumoconiosis contains many contradictions in the assessment of the pathogenetic mechanisms of lung damage, in particular, the morphogenesis of neoplastic changes in the respiratory system at the final stage of the disease with pronounced sclerotic changes. The study is devoted to the occurrence and development of tumor tissue in the miners working in the underground conditions. The task is to identify morphological trigger mechanisms for the development of oncological pathology in miners, relying on pathomorphological, immunohistochemical studies of the changes in the epithelial tissue of the airways, as well as various cellular communities of the bronchi, blood vessels of the lungs and lung tissue parenchyma using the example of epithelial-mesenchymal transformation under dust load.

The purpose of this study was to determine the influence of the fibroplastic process on the development of oncological pathology in miners who worked in underground conditions.

Materials and methods. Histological, immunohistochemical and morphometric studies of the respiratory system obtained during 50 autopsy works of a group of Kuzbass miners working in underground conditions was carried out. Cancer of various localization and histogenetic affiliation was previously diagnosed in 20 miners. The mucous membrane of the bronchi, respiratory tissue of the lungs, arteries and veins of the pulmonary circulation were studied. Immunohistochemical study was performed using monoclonal antibodies (marker of proliferation Ki-67, oncogene of proapoptotic activity Bcl-2, growth and neoangiogenesis factors, endothelial function factors CD-31 and CD-34, marker of epithelial tissue cytokeratin (cyt), muscle tissue markers — actin, desmin, vimentin, connective tissue markers — collagen, laminil, markers of intercellular interactions EMA, SMA).

Results. Transformed fibroblasts, myofibroblasts are a cell population of dedifferentiated epithelial tissue with different expressions of nonspecific markers (desmin, actin, vimentin), capable of tumor transformation. Sclerotic tissue changes in pneumoconiosis are the areas of tumor transdifferentiation. Fibroblasts with an altered phenotype, namely myofibroblasts, are able to give rise to the growth of undifferentiated mesenchymal cell communities (tumor tissue), including atypical epithelial cells, adipocytes, chondrocytes and endotheliocytes.

Conclusions. Epithelial-mesenchymal transformation can be a triggering mechanism for the development of tumor transformation from extensive fibrosed zones in miners with dust lung pathology. In this case, the main etiological factor of tumor progression is activated fibroplastic cells.

Introduction. Objective assessment of the noise redaction (NR) of individual hearing protection devices (HDP) in industrial conditions is actual problem despite numerous studies in this direction in many countries.

This study aimed to implement the F-MIRE method for measuring the NR of HDPs, considering the transfer function of the outer ear.

Materials and methods. HDP performance indicators measured by the real ear attenuation threshold (REAT) method in the free field, do not fully reflect the protective properties of HDP in specific production conditions and for a specific employee, according to many researchers.

The measurement method using two microphones, called Field-MIRE (F-MIRE), allows you to determine NR as the difference in sound pressure, external noise and noise inside the external auditory meatus (EAM). But since these microphones are located in different acoustic conditions, it becomes necessary use at least two blocks of correction coefficients to get real results. One block — considering the properties of the acoustic probe, the second — should consider the transfer function of open ear.

The measurements of the TFOE in 18 volunteers and the evaluation of the NR of the SOMZ-1 "Jaguar" earmuff in industrial conditions were carried out.

Results. This study has shown the effectiveness of the implementation of the F-MIRE method for an adequate assessment of the NR of earmuff in industrial conditions. The special headband uses for measuring the TFOE allows you to standardize the location of measuring microphones relative to the volunteer's head and reduce the uncertainty of measurements. Unlike the REAT method with binaural listening in a free field, the F-MIRE method allows you to determine the TFOE for each ear of an employee. Our research has shown that TFOE differences between the right and left ears one-man can be significant.

Conclusion. The NR determination by the difference of sound pressures measured by an external microphone and a MIRE microphone, without considering the acoustic properties of the outer ear underestimates both spectral and single-digit NR indicators.

Introduction. JSC "Russian Railways" monitors morbidity and changes in the health status of employees, including after the use of high-tech assistance methods (radiofrequency ablation, joint replacement, etc.).

In some cases, JSC "Russian Railways" made decisions on individual admission to training work of persons who have undergone such high-tech interventions, even if there are medical contraindications to work.

The study aims to learn the feasibility of individual admission to work of train personnel after high-tech medical care. Furthermore, it makes the professional longevity of railway transport workers.

Materials and methods. We analyzed the information for 2015–2020 about the identified medical contraindications in workers directly related to training traffic and shunting work, with rhythm and conduction disorders, surgical diseases, and lesions of large joints, including those aimed at high-tech assistance. In addition, the researchers evaluated the clinical and economic efficiency of their admission to work.

Results. More than 70% of employees after radiofrequency ablation and joint replacement can return to train workers, which has brought an indirect economic effect of at least 150 million rubles over six years. It is a prerequisite for the revision of existing regulatory documents.

Conclusions. The use of high-tech treatment methods makes it possible to prolong professional longevity through individual admission to train employees of the group of machinists, drivers, and their assistants. The research showed an indirect economic effect for the railway industry for at least 150 million rubles over six years, which is the basis for changing medical expert approaches and medical contraindications to work directly related to training traffic.

Introduction. We present the study results of pilots of different age groups about the role of campaign policies in ensuring the safety of flights, health, and social well-being of pilots.

The study aims to learn the ideas of civil aviation pilots of different age groups about the role of campaign policies in ensuring flight safety.

Materials and methods. The researchers used the following methods as empirical research methods: focus group method, content analysis of pilots' statements, frequency analysis method, implemented in the SPSS-20 program.

Results. According to the frequency analysis results, we identified adverse factors of the labor process that negatively affect flight safety. Of these, the most damaging factors of labor activity are: a violation of the elements and features of the organizational, legal and material, and economic management subsystems (organizational characteristics) — 97.5% of respondents; infringement of the work and rest regime of civil aviation pilots — 100% of respondents; stress in the workplace — 92.5% of respondents; poor-quality training — 77.5%; manipulation of wages — 77%.

Conclusions. The analysis of the obtained results allows us to conclude that the management policy of the organization and personnel is a crucial factor determining flight safety, a high level of motivation to work, productivity, and health of pilots

Alcohol abuse is one of the main lifestyle factors affecting the health of the Russian population and determining the level and dynamics of morbidity and mortality from chronic non-communicable diseases. Alcohol addiction is one of the most difficult and dangerous diseases for humanity due to the enormous medical, social, moral, ethical, economic and spiritual losses. Alcohol damage is associated with medical expenses, reduced labor productivity, premature death. In the Concept of the implementation of the state policy to reduce alcohol abuse and prevent alcoholism among the population of the Russian Federation for the period up to 2020, it was stated that "alcohol abuse causes a particularly high mortality rate among men 40-60 years old, who at this age have the most valuable professional skills; their premature death damages the workforce with professional experience, reduces the amount of investment in human capital". Conducting an anti-alcohol program within the framework of occupational medicine seems to be an effective method of solving the problems of both the drinker himself and society as a whole. Alcohol risk management of Russian enterprises is a very promising and in-demand area of scientific and practical activity, which is of great interest to physicians, managers, economists and representatives of many other fields and professions.

The organization of work of workers of various professions associated with intense and quite often intense interpersonal communication is an object of increasingly active attention. This applies to medical professionals. Medical workers experience psycho-emotional overload, which can lead to diseases, a decrease in the quality of life. The COVID-19 pandemic has particularly acute the problem of professional burnout syndrome among medical workers. The article discusses the role of quality of life indicators in assessing the syndrome of professional burnout in different categories of workers. Professional burnout syndrome is a significant and relevant medical and social problem, and aspects related to the quality of life can considerably impact the risk of developing professional burnout syndrome.

Researchers surveyed secondary school teachers characterizing the signs of emotional burnout during the educational process in a distance format. We considered preventive measures.

The study aims to research the possible development of emotional burnout among teachers in the conditions of distance learning.

We conducted a study with the participation of 72 teachers to identify signs of emotional burnout using the V.V. Boyko questionnaire and conducted statistical data processing using Statistica 13.0.

The average age of teachers was 47.1 years; the majority were women. In addition, 70,0% of Teachers noted that they have chronic diseases. Based on the results obtained, we concluded that school teachers' lack of work experience in the conditions of distance learning and online classes was a traumatic circumstance for almost half of the teachers, which could serve as a triggering mechanism for the stages of development emotional burnout. Subjectively, teachers associated the formation of symptoms of emotional burnout and health disorders with two-thirds of all cases with working conditions, its intensity, and difficulties with maintaining a healthy lifestyle in self-isolation.

The revealed indicators of the phases of the development of emotional burnout allow us to judge that 45.9% of teachers have a formed/dominant symptom of "experiencing traumatic circumstances" registered in the "tension" phase. 31.2% of teachers have a symptom of "anxiety and depression". There are high rates of symptoms of "inadequate selective emotional response" — 54.1% in the "resistance" phase, "emotional and moral disorientation" — 32.8%, "expansion of the sphere of saving emotions" — 31.1% and "reduction of professional responsibilities" — 50.8%. In the "exhaustion" phase, the symptom "psychosomatic and psychovegetative disorders" has a dominant value in 22.9% of teachers.

Factors that, according to teachers, contribute to the formation of emotional burnout are: the intensity of work in the conditions of distance learning (61.1%); violation of  lifestyle components (36.1%); lack of access to a doctor (29.2%).

To prevent the formation of emotional burnout syndrome in the conditions of distance learning: it is necessary to observe for teachers the work and rest regime in compliance with the working time regulations within the framework of official duties and an employment contract, compliance with the rules of a healthy lifestyle, high-quality medical care, and mandatory professional development on online training.