Modern weapons cause severe damage, accompanied by high rates of complications and mortality. The investigation of such kinds of weapons is in high demand considering the ongoing active phase of ...russia's war against Ukraine since February 2022. In order to understand the pathological processes that occur in and outside the gunshot wound, we conducted an experimental study using mathematical simulation. The results presented in the article will help to choose the appropriate surgical management and improve the results of treatment. The aim of this study was to investigate and evaluate the damaging effect of a 5.45 mm 7N6M bullet and a 5.45 mm V-max expansive bullet using numerical modeling of wound canals in ballistic plasticine. The Ansys Explicit Dynamics engineering complex was used to simulate the dynamics of the bullet’s motion. The basic equations, solved by the explicit dynamic analysis, express the conservation of mass, momentum, and energy in Lagrange coordinates. Together with the material model and the set of initial and boundary conditions, they determine the complete solution to the problem. Taking into account that the initial velocity of the bullet is 1185 m/s at a mass of 3.9 g, we obtain energy 2740 J. All this energy acts at the area of the wound canal with a depth of 150 mm. Injury with a conventional 7N6M bullet is characterized by the fact that it passes through the block and loses only part of the kinetic energy. The simulation results showed that the velocity of the bullet at the outlet is 220 m/s. Taking into account the initial velocity of the bullet 918 m/s with a mass of 3.4 g, we obtain the kinetic energy acting on the walls of the wound canal with a depth of 200 mm of about 830 J. Mathematic analyses showed that the expansive bullet has a soft core that deforms and transfers all the kinetic energy to the tissues immediately after penetration into the tissues. The loss of kinetic energy of the bullet (ΔE, J) is defined as the difference between the kinetic energy at the time of injury (Ec, J) and the residual energy of the bullet when leaving the material (Er, J). Numerical modeling of wound ballistics in biological tissue simulators allows us to determine with high accuracy the features of wound canal formation and tissue response to damage of bullets having different kinetic energy, which contributes to the choice of adequate surgical management during surgery for gunshot wounds.
Purpose of the study the peculiarities of rearrangements of skeletal muscle fibroblasts surrounding the wound canal at various times after an experimentally modeled gunshot shrapnel wounds. ...Experimental modeling of gunshot shrapnel wounds of soft tissues has been carried out on 20 laboratory animals - breeding rabbits of the breed «Chinchilla». To laboratory animal was caused a gunshot wound in the sartorius area with the gun «Fort-12» caliber 9 mm. The initial velocity of the fragment was 305 m/s. Ultrathin muscle sections were examined using an EM-125 electron microscope at accelerating voltage of 75 kV, with a magnification of 20000 - 60000 arm. In an experiment it was revealed that on the thirtieth day most of the fibroblasts of the wound canal in the femoral muscle tissue had an ultrastructure characteristic of the course of compensatory-adaptive, synthetic, and reparative processes. Sixty days after a gunshot wound, the submicroscopic organization of fibroblasts from the wound canal area undergoes disorders associated with a decrease in the synthetic activity of fibroblasts.
Based on the analysis of a large volume of the literature data concerning simulation of thrombotic conditions in laboratory animals under experimental conditions, the authors discuss various models ...of venous thrombosis. The method proposed by S. Wessler et al. (1959) is considered to be the simplest, most readily reproducible, and least invasive one. It consists of a combination of venous hyperemia and hypercoagulation induced by the administration of an activated coagulation factor.
Based on the analysis of a large volume of the literature data concerning simulation of thrombotic conditions in laboratory animals under experimental conditions, the authors discuss various models ...of venous thrombosis. The method proposed by S. Wessler et al. (1959) is considered to be the simplest, most readily reproducible, and least invasive one. It consists of a combination of venous hyperemia and hypercoagulation induced by the administration of an activated coagulation factor.
We examined 128 patients with obstructive jaundice of non-tumoral genesis that were surgically treated. We studied the immune status and plasma concentration of interleukine-8 in pre-operation period ...in order to predict the polyorganic insufficiency (PI) risk. Depending on the results obtained, patients were divided into groups defined as those of low or high risk of PI. This permitted to apply differentiated treatment with the use of multi-grade surgical intervention and extracorporal detoxication. This contributed to decrease of post-operative complications rate and mortality.
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