A Model of Acute Peritonitis.

The biological models used in the study of generalized peritonitis can be subdivided into 5 groups (introduction of foreign bodies, cultures of microorganisms, suspensions of feces, chemicals, and mechanical damage to the gastrointestinal tract) or into 4 groups (introduction of foreign bodies, chemicals, bacterial contamination of the abdominal cavity, and combined methods). After analysis of published reports, the most justified classification of methods of peritonitis modelling is based on the type of peritonitis-inducing agent and the administration route and on the nature of peritonitis developing in the abdominal cavity. The choice of the model maximally close reproducing clinical conditions of peritonitis should be based on the specific objectives of the study, focusing on the etiology, pathogenesis, and severity of the disease course, planned measures aimed at eliminating the process, and other factors.

Simulation of Mechanical and Thermal Wounds of Soft Tissues.

Millions of accidental and surgical injuries of soft tissues are registered annually around the world [5]. Untimely and insufficiently effective treatment of wounds in 50-70% leads to the development of purulent-septic infection and the development of septic conditions and fatal outcomes [1-4], which necessitates thorough study of inflammatory and regenerative processes occurring in the injured soft tissues. Various models of mechanical and thermal damage to soft tissues are proposed for studying the inflammatory and reparative processes, for assessing the therapeutic effects and developing new approaches to wound treatment.

A Dynamic 6,000-Year Genetic History of Eurasia's Eastern Steppe.

The Eastern Eurasian Steppe was home to historic empires of nomadic pastoralists, including the Xiongnu and the Mongols. However, little is known about the region's population history. Here, we reveal its dynamic genetic history by analyzing new genome-wide data for 214 ancient individuals spanning 6,000 years.

The Effects of Mechanical Preload on Transmural Differences in Mechano-Calcium-Electric Feedback in Single Cardiomyocytes: Experiments and Mathematical Models.

Transmural differences in ventricular myocardium are maintained by electromechanical coupling and mechano-calcium/mechano-electric feedback. In the present study, we experimentally investigated the influence of preload on the force characteristics of subendocardial (Endo) and subepicardial (Epi) single ventricular cardiomyocytes stretched by up to 20% from slack sarcomere length (SL) and analyzed the results with the help of mathematical modeling. Mathematical models of Endo and Epi cells, which accounted for regional heterogeneity in ionic currents, Ca handling, and myofilament contractile mechanisms, showed that a greater slope of the active tension-length relationship observed experimentally in Endo cardiomyocytes could be explained by greater length-dependent Ca activation in Endo cells compared with Epi ones.