[On the study of postmortem tissue changes' dynamics according to impedance metrics data]. / K voprosu izucheniya dinamiki postmortal'nykh izmenenii tkanei po dannym impedansometrii.

OBJECTIVE: To find a way and form of presenting impedance metrics data to clarify prescription of death coming in a comprehensive assessment. MATERIAL AND METHODS: The impedance of biological objects was measured depending on prescription of death coming in standardized conditions (air temperature +4 °C, humidity 45%). The main examined postmortem period was 1 months. Measurements were made on 3 diagnostic zones of biological object and for 5 current frequency of the study. A total of 2100 readings were taken. RESULTS AND CONCLUSION: The studies performed in standardized conditions have showed that using impedance metrics method to diagnose prescription of death coming is possible. The analysis of only absolute impedance values is not sufficient to clarify prescription of death coming due to its undulating changes. The additional use of relative coefficients, characterizing impedance dispersion, is suggested. The study of possible using the impedance indicators of corpse's tissues to determine prescription of death coming should be performed with consideration to pathomorphology of degradation. Further study of impedance dynamics when corpse is under different conditions is necessary for development of a working algorithm to determine prescription of death coming based on tissue impedance.

[On the prospects of the impedance monitoring method for determining the prescription of death coming]. / O perspektivnosti metoda impedansometrii dlya opredeleniya davnosti nastupleniya smerti.

The aim of the scientific work is to analyze the prospects of using the impedance monitoring method to determine the prescription of death coming. The conducted exploratory analysis allows hypothesizing the dependence of impedance values and dispersion factors for the diagnostic zones studies on the postmortem interval; it also suggests that it is possible to determine this interval for the objects (pig corpses) studies with a combination of impedance values and the corresponding factors. Among large mammals, a swine is the closest to a human from the point of analyzing the postmortem period process, and it can be recommended as an adequate human corpse model. When determining the correlation between the postmortem interval and the impedance parameters, it is the simplicity and reproducibility of the method, the absence of expensive equipment, its portability and the rapid receipt of results that allow this method to be applied at the scene, reinforcing traditional forensic methods for determining the prescription of death coming. Interpretation of impedance monitoring results can be used to analyze the biological nature of the postmortem period processes.

[On using the corpses of large mammals as model objects for studying the postmortem period]. / Ob ispol'zovanii trupov krupnykh mlekopitayushchikh v kachestve model'nykh ob"ektov pri izuchenii postmortal'nogo perioda.

THE AIM OF THE STUDY: Is to justify using the corpses of large mammals as model objects for studying the postmortem period. Similarities in processes occurring postmortem in human and swine corpses (decomposition stages and the structure of dominant necrophilic organisms inhabiting the corpse), as well as similar changes of relative impedance parameters for the cartilaginous tissue and musculoskeletal flap of swine and human corpses have been established. The results obtained allow recommending the swine corpse as an adequate human corpse model both for scientific studies and for solving specific scientific and practical issues arising in the practice of forensic examination when determining the prescription of death coming and the postmortem period conditions.

[Practical value of microorganisms for forensic purposes (on the example of microbial flora of bony remnants from the historic burial site)]. / Prakticheskoe znachenie mikroorganizmov dlya tselei sudebnoi meditsiny (na primere mikroflory kostnykh ostankov istoricheskogo zakhoroneniya).

Phenotypic signs of dominants isolated from the surface of bony remnants from the historic burial site were analyzed in order to expand data on the biodiversity of microorganisms in the microbial flora of bony remnants and to assess the possibility of using the results of microbiological analysis in the evidence base of forensic examination and forensic archaeology. It was detected that only Deuteromycota and Eubacteria colonized all types of surfaces in the samples of bone fragments from the historic burial site (with the age in the range of 90-95 years); with the abundance of micromycetes, the proportion of Eubacteria naturally decreased, while with the increased bacterial background counts the rate of micromycetes detection decreased. The insignificant amount of nutrients in the bony remnants led to the decrease in the number and biological diversity of microorganisms contaminating them; species adapted to a hard-to-reach organic substrate dominated there. During the process of bony remnants decomposition, when the conditions of their location changed, inter-species competition and specific recolonization occurred by species of microorganisms most adapted to a hard-to-reach organic substrate in the abiotic and biotic conditions of existence given. The results obtained are important for the descriptive ecology and biology of specific groups of microorganisms in the postmortem microbiome and form the basis for a more thorough study of complex communications between species of microorganisms in the necrobiome of bony remnants - in the future it will allow putting forward original hypotheses about the involvement of microbes in the circulation of matter and energy, as well as to apply the information obtained in the evidence base of forensic examination and forensic archaeology.

[Rare cases of head traumas incited by propeller blades of small vessels]. / Redkie sluchai travm golovy, prichinennykh lopastyami grebnykh vintov malomernykh sudov.

2 cases of death in males due to multiple head impacts by propeller blades of small vessels are given. The set of the following signs provides a basis for confirming the above-mentioned mechanism and properties of the traumatic object: multiplicity, oblong shape, parallel step-like arrangement of injury lengths, acute-angled M-shaped or Y-shaped injury ends, uneven edges, sometimes with the formation of small flaps and abrasion, lumpy wound walls, multi-fragmented nature of fractures in a limited area of the skullcap and facial skull bones, the location of damage to intracranial structures in the projection of external injuries and fractures of the cerebral skull bones.

[75 years in the service of Karelia: to the anniversary of the State Medical Institution of the Republic of Karelia Bureau of Forensic Medical Examination]. / 75 let na sluzhbe Karelii: k yubileyu GBUZ RK «Byuro sudebno-meditsinskoi ekspertizy¼.

The article is dedicated to the 75th anniversary of the State Budgetary Healthcare Institution of the Republic of Karelia «Bureau of Forensic Medical Examination¼. The history of the formation of the forensic medicine service in the Republic of Karelia is briefly described. The data on the heads of the service and well-known forensic experts, the organizers of the forensic medical examination in Karelia, the course of forensic medicine of Petrozavodsk State University, the role of its employees in the work of the State Medical Institution of the Republic of Karelia «Bureau of Forensic Medical Examination¼ are presented. In addition to available literature sources, archival materials of employees and veterans of the forensic medical service of Karelia were used.

[Unusual expert observation of death of a man from falling into a working sawmill]. / Neobychnoe ekspertnoe nablyudenie smerti muzhchiny ot popadaniya v rabotayushchuyu diskovuyu piloramu.

An unusual expert observation of the death of a man from falling into a working disk sawmill is presented. As a result of the forensic medical examination of the corpse, a sawn wound of the right lower limb with subtotal traumatic amputation at the level of the upper third of the lower leg was found. The above observation complements the forensic understanding of the relatively rare sawn injuries caused by circular saws in production conditions. Despite the surgical intervention that took place in the described case, which led to a modification of the primary picture of sawn damage, it remains possible to diagnose the damaging factor, some of its characteristics, the mechanism of action and solve the situational problem.

[Suicide by electric shock with the use of engineering skills]. / Samoubiistvo elektricheskim tokom s primeneniem inzhenernykh navykov.

A case of suicide using technical electricity is presented. The fact of electrical injury is confirmed by the typical macroscopic and microscopic picture of an electric mark. The location of the conductors on the body indicated the victim's knowledge of the effect of electric current on the human body, the ways of its propagation through the body through the vital organs, preparation and determination in the implementation of suicidal intentions. The interest of this case lies in the fact that electrical injury as a method of suicide is extremely rare in expert practice.

[Ecological aspects of postmortem microbiome and possibility of their use in forensic practice]. / Ekologicheskie aspekty posmertnogo mikrobioma i vozmozhnost' ikh ispol'zovaniya v praktike sudebno-meditsinskoi ekspertizy.

Through experimental reproduction of the decomposition process using the cadaver of rabbit Oryctolagus sp., the dynamics of cadaver microflora was studied; the dominant bacterial taxa were isolated in pure culture and identified; their ecological and trophic profiles and biodiversity were described based on the values of Simpson and Menchinic ecological indices. The dependence of cadaver rotting and skeletonization rate on the taxonomic profile of microorganisms, decomposition period, and abiotic environmental factors (temperature, acidity, soil moisture) was demonstrated. The data obtained contribute to justifying the use of microbiological methods in forensic practice. To establish objective causality patterns of microbial transformation of organic matter in nature, further targeted study of ecological patterns of cadaveric microflora is necessary.

[Neck shot suicide from TOUA-307 construction and installation gun]. / Samoubiistvo putem vystrela v sheyu iz stroitel'no-montazhnogo pistoleta TOUA-307.

Construction and assembly pistols are widely used but single observations are described in the forensic medical literature and, as a rule, concerning shots to the head. An unusual case of suicide by a shot in the neck from a TOUA 307 construction and assembly pistol is presented: a blind shell wound was found to the left half of the neck and with damage to the cervical spine and spinal cord. The above observation complements the existing ideas about the possibility of causing self-harm from an atypical weapon - a construction and assembly pistol.

[On the question of justifying the choice of a model-object for studying the dynamics of impedance in the postmortem period]. / K obosnovaniyu vybora model'nogo ob"ekta dlya issledovaniya dinamiki impedansa v posmertnom periode.

Objective - to compare the temporal dynamics of the tissue impedance of human and pig corpses under the same conditions to substantiate the further use of pig corpses as model objects. At the first stage, we studied the tissue impedance values obtained on 4 pig cadavers with a known date of death measured with a Keysight U1731 parting. The necessity of using a model object for studying the dynamics of impedance in the postmortem period has been substantiated. An exploratory analysis was carried out that allows to put forward a hypothesis about the existence of the impedance values (absolute indicators) and dispersion coefficients (relative indicators) dependence on the time of death, and also suggests that the combination of impedance values and the corresponding coefficients can be used to judge its duration for the objects under study.

[Features of physiological groups of microorganisms - participants in the diagenesis of bone remains]. / Osobennosti fiziologicheskikh grupp mikroorganizmov ­ uchastnikov diageneza kostnykh ostankov.

Objective - to study the diversity of physiological groups of microorganisms that control the transformation of bone remains in nature. Traditional microbiological methods were used to study the cytological, physiological, biochemical and environmental properties of microorganisms isolated from the bone remains of Oryctolagus sp. 8 of 14 physiological groups of microorganisms - participants of diagenesis are established: ammonifiers, nitrifying bacteria, bacteria decomposing cellulose, causative agents of lactic acid and acetic acid fermentation, nitrogen fixators and denitrifying bacteria. Most of the identified physiological groups are in constant dynamics that is probably due to the uneven distribution in the soil of organic substances formed at different times in the process of microbial transformation of bone fragments. The analysis of qualitative and quantitative characteristics of these microorganisms' groups makes it possible not only to assess the intensity of the processes taking place over time but also to define the dependence on environmental factors such as soil acidity and ambient temperature. The results obtained can be used to obtain reliable data in forensic medical examination to solve issue about the prescription of death or the term of burial of bone remains.

[On the possibility of luminol solution usage to detect the blood traces when examining the scene]. / O vozmozhnosti ispol'zovaniya rastvora lyuminola dlya obnaruzheniya sledov krovi pri osmotre mesta proisshestviya.

Objective - to present a comparative analysis of the specialized literature on the possibility of using a luminol solution to detect blood traces when examining the scene of an incident. The use of this sample at the incident scene is only preliminary, since its high sensitivity connected with nonspecific properties. Information about the possibility of identifying the species, group and DNA belonging of blood traces after their treatment with a luminol solution is contradictory, therefore, its use at the scene should be careful with the preservation of intact (not treated with luminol) blood traces available for their study by traditional forensic biological methods. The possibility of laboratory determination of the properties of blood after processing its traces with a luminol solution can be proved by a special scientific and experimental forensic biological work.

[An unusual case of suicide using an angle grinder]. / Neobychnyi sluchai samoubiistva s ispol'zovaniem uglovoi shlifoval'noi mashinki.

An unusual case of suicide using an angle grinder is presented. A forensic examination of the corpse revealed an injury to the soft tissues of the neck with a complete transverse intersection of the neurovascular bundles, organs of the neck and cervical spine caused by a rotating disc of an angle grinder. This observation supplements the existing ideas about the possibility of using power tools for various purposes with suicidal purposes.

[On the issue of a comprehensive diagnosis of death coming in the late postmortem period]. / K voprosu o kompleksnoi diagnostike davnosti nastupleniya smerti v pozdnem posmertnom periode.

According to specialized literature and the results of our own experiments to carry out a comprehensive study to find criteria for determining the time of death in the late postmortem period. It turned out that a combined assessment of microbiological, entomological and biophysical data obtained in the study of a corpse is advisable for medical diagnostics of the duration of the postmortem interval, which does not exclude the need to compare them with the results obtained by traditional morphological methods. From an applied point of view, it is very important to «standardize¼ the conditions of such studies. For an in-depth study of the nature of cause-and-effect relationships of phenomena occurring in biological tissues in the late postmortem period, it is very interesting to perform microbiological, entomological and biophysical studies under different environmental conditions, but according to a single program and on a single methodological basis.

[To the study of the corpse tissues' impedance dynamics in the late postmortem period]. / K izucheniyu dinamiki impedansa tkanei trupa v pozdnem posmertnom periode.

The purpose of this work is to establish the dynamics of the electrical conductivity of various corpse tissues using impedance measurements to assess this method for diagnosing the time of death. It was studied the values of the tissue impedance from the corpses of 8 persons of both sexes and different ages (30-50 years) who died from various causes, with the known date of death. A Keysight U1731 parting was used with two probes, which are stainless steel needles with a diameter of 0.5 mm and a 5 mm immersion length. The analysis of special literature on using indicators of the electrical conductivity dynamics of the corpse tissues, determined by the method of impedance measurement, in the early and late postmortem periods to diagnose the time of death. Trial measurements of a methodological nature were carried out with diagnostic zones: skin, cartilage tissue and tendon. The impedance-metric approach is promising for the purposes of forensic medical diagnostics of the time of death; however, it requires more careful experimental work to establish the dynamics of changes in the total electrical resistance of various tissues of a whole corpse over a long period from the moment of death.

[Prospects for molecular-genetic support of research on proteolytics in the necrobiome composition]. / Perspektivy molekulyarno-geneticheskoi podderzhki issledovanii proteolitikov v sostave nekrobioma.

The aim of this work is to monitor the state of the proteolytic community in time and space for the subsequent development of approaches to an objective assessment of the late postmortem period. The study proposes a combination of standard bacterioscopic and bacteriological research methods with methods of molecular biology and genetics, which make it possible to identify species and strains of mammalian corpses' proteolytics at the level of specific DNA or RNA. On the basis of phenotypic traits and a comparative analysis of the nucleotide sequences of genes encoding 16S rRNA, the species belonging of the isolated strains was proved. The set of methods' combination, including traditional microbiological analysis and molecular genetic studies, seems promising both for the purpose of substantiating and widespread use of microbiological methods in forensic medical practice, and for development an objective scientific base for establishing the cause-and-effect patterns of microbial transformation of organic matter in nature.

[Unusual case of suicide by hanging from the cab door of a MAN truck]. / Neobychnyi sluchai samoubiistva putem povesheniya na dveri kabiny gruzovogo avtomobilya «MAN¼.

An unusual case of suicide by hanging on the door inside the cab of a truck (truck) «MAN¼ is presented: the neck is squeezed between the edge of the movable glass and the edge of the frame of the car door from the driver's seat. The above observation supplements the existing variants about the possibility of hanging with a kind of one-sided open «loop¼.

[Integrative microbial-zoological assessment of the postmortem period in forensic medical examination]. / Integrativnaya mikrobno-zoologicheskaya otsenka posmertnogo perioda dlya tselei sudebno-meditsinskoi ekspertizy.

THE AIM OF THE STUDY: Is a complex microbial-zoological characterization of the post-mortal period and ways of its determination during forensic examination. The heterotrophic component of the microflora of the corpse and its bed were studied using standard methods of microbiological research and PCR analysis, necrophilic insects - entomological method, and damages from some vertebrate animals - traditional methods of their analysis. We studied 125 corpses of humans, pigs, chickens, mice and some other representatives of mammal class weighing from 100 g to 100 kg at different times of decomposition. We isolated and studied more than 1000 isolates of microorganisms, more than 32 000 insects and more than 100 damages caused by rodents, dogs, cats and birds. We determined the main trends in microbial decomposition of dead bodies. The general characteristics of the corpse decomposition by insects are given and anatomical-topographical and morphological features of the corpse damage by some vertebrates are established. Significant The heterotrophic component of the microflora of the corpse and its bed were studied using standard methods of microbiological research and PCR analysis, necrophilic insects - entomological method, and damages from some vertebrate animals - traditional methods of their analysis. We studied 125 corpses of humans, pigs, chickens, mice and some other representatives of mammal class weighing from 100 g to 100 kg at different times of decomposition. We isolated and studied more than 1000 isolates of microorganisms, more than 32 000 insects and more than 100 damages caused by rodents, dogs, cats and birds. We determined the main trends in microbial decomposition of dead bodies. The general characteristics of the corpse decomposition by insects are given and anatomical-topographical and morphological features of the corpse damage by some vertebrates are established. Significant microbial and zoological characteristics of the post-mortem period have been identified, and ways of its establishment have been determined and confirmed by practical testing during forensic examination. A set of practical recommendations has been developed for forensic experts on the collection of necrophilous insects during the examination of the corpse at the scene and the tactics of the examination with the involvement of entomologists. The results obtained prove that there is a close correlation between the impact of vertebrate scavengers, necrophilic insects and the enzymatic activity of a specific community of heterotrophic microorganisms on the corpse.

[Features of bone destruction due to the collagenase activity of bacteria of the Bacillus and Clostridium genera]. / Osobennosti destruktsii kostnoi tkani za schet kollagenaznoi aktivnosti bakterii rodov Bacillus i Clostridium.

The purpose of work was to study the activity of collagenase biosynthesis by bacilli and clostridia isolated from the bone microflora in a pure culture at different periods of bone decomposition and at different values of acidity of the medium and the temperature of cultivation. The comparative collagenase activity of the strains of Bacillus mycoides, Bacillus subtilis, Clostridium putrificum, Clostridium sporogenes found in microflora of bone tissue was determined. The catalytic activity of collagenases was evaluated according to the modified method of agar blocks by the diameter of precipitation zone as a result of diffusion of enzyme into an agar medium with collagen. Within 6 months of experiment, the dynamics of changes in the number of collagenolytic strains was monitored. For all isolated Bacillus and Clostridium isolates, a steady increase in collagenase synthesis was observed throughout the study period, with the exception of Bac. subtilis, which is probably due to the acidity of medium, which did not correspond to the optimal pH range for this species. The optimum temperature for manifestation of the maximum collagenolytic activity of bacilli was 40 °C, and for clostridia - 30 °C. The study of proteolytically active species involved in the destruction of bone collagen is promising for the purposes of forensic examination. The use of bacterial enzymes in forensic practice remains a difficult task, however, the use of their substrate specificity can significantly expand the evidence base of the examinations.