Two- and Three-particle States in a Nonrelativistic Four-fermion Model in the Fine-tuning Renormalization Scheme. Goldstone mode "against" extension theory

In a nonrelativistic contact four-fermion model we show that simple regularisation prescriptions together with a definite fine-tuning of the cut-off-parameter dependence of ``bare'' quantities give the exact solutions for the two-particle sector and Goldstone modes. Their correspondence with the self-adjoint extension into Pontryagin space is established leading to self-adjoint semi-bounded Hamiltonians in three-particle sectors as well. Renormalized Faddeev equations for the bound states with Fredholm properties are obtained and analysed.Comment: 23 pages, LaTeX, changed content, added references and two figures, to appear in the Few Body System

A case of xenon inhalation therapy for respiratory failure and neuropsychiatric disorders associated with COVID-19

Acute respiratory distress syndrome (ARDS) is the main danger to the life of patients with pneumonia caused by SARS-CoV-2. At the same time, respiratory failure (RF) after ARDS can persist for a long time despite intensive therapy. Therefore, it is important to develop new effective approaches for restoring the ventilation function of the lungs after COVID-19. Here, we present a case report of effective application of short-term inhalations of xenon-oxygen (Xe/O2) gas mixture for treatment of RF and neuropsychiatric disorders (NPD) associated with COVID-19. The patient inhaled a gas mixture of 70 % Xe and 30 % O2. We used multispiral computed tomog-raphy, evaluated psychometry, studied hematological and biochemical blood parameters, and applied some other methods of clinical studies to assess the therapeutic effectiveness of Xe inhalation. Also, we studied the mecha-nism of action of xenon with computer modeling. The clinical case showed the high efficacy of Xe/O2 mixture for treating severe RF and NPD after SARS-CoV-2 infection. Xenon inhalations dramatically increased oxygen saturation and the degree of pneumatization of the lungs. We found out that in coronavirus pneumonia, saturated phospholipids of surfactant are transferred to the solid-ordered phase, which disrupts the surface tension of the alveoli and alveolar gas exchange. Using molecular modeling methods, we demonstrated that the xenon atom in-creases the distance between the acyl chains of phospholipids due to the van der Waals dispersion interaction. These changes allow for the phase transition of phospholipids from the solid-ordered phase to the liquid phase and restore the functional activity of the surfactant. The findings suggest the feasibility of conducting studies on the effectiveness of Xe/O2 inhalations for treating ARDS in SARS-CoV-2 infection

Global and Glocal Trade Streams Assessment in the Subjects of the Northwestern Federal District Trade

The relevance of the article is connected with the fact that the phenomenon of globalization and the related process of a glocalisation needs a quantitative assessment. The purpose is to establish the factors having universal meaning for the export of all subjects of the Northwestern Federal District and factors having special meaning for some of them. Secondly, our purpose was to define a weight of these special (glocal) variables in comparison to global. The gravitation equation characterizing the main regularities of export of the Northwestern Federal District subjects is received. The quality of the model for forecasting is sufficient. The simplified gravitation equation in a multiplicative form is offered. Model lets to establish export of the subject of the Northwestern Federal District connection with variables of glocality (existence of the common sea and belonging of the country of import to the European continent). Existence of the common overland borders doesn’t play an essential role. The share of the glocal factors defining the streams of foreign trade makes 11%. The signs which distinguish trade of border subjects are: the volume of trade is higher than an average; in each bilateral direction goods of three or more Harmonized System chapters are shipped. Export dependence on global characteristics such as the level of regional economic integration of the country and the Liner Shipping Connectivity Index for St. Petersburg is more significant than for the Northwestern Federal District in general. The practical value of work consists in the fact that it confirms importance of the European countries as trade partners for subjects of the Northwestern Federal District