THz transition radiation of electron bunch laser-accelerated in long-scale near-critical density plasmas

Direct laser electron acceleration in near-critical density plasma produces collimated electron beams with high charge $Q$ (up to $\mu$C). This regime could be of interest for high energy THz radiation generation, as many of the mechanisms have a scaling $\propto Q^2$. In this work we focused specifically on challenges that arise during numerical investigation of transition radiation in such interaction. Detailed analytical calculations that include both diffraction and decoherence effects of characteristics of transition radiation in the THz range were conducted with the input parameters obtained from 3D PIC and hydrodynamic simulations. The calculated characteristics of THz radiation are in good agreement with the experimentally measured ones. Therefore, this approach can be used both to optimize properties of THz radiation and distinguish the transition radiation contribution if several mechanisms of THz radiation generation are considered

Laser-driven pointed acceleration of electrons with preformed plasma lens

The simultaneous laser-driven acceleration and angular manipulation of the fast electron beam is experimentally demonstrated. The bunch of multi-MeV energy charged particles is generated during the propagation of the femtosecond laser pulse through the near-critical plasma slab accompanied by plasma channeling. Plasma is formed by the controlled breakdown of a thin-tape target by a powerful nanosecond prepulse. The electron beam pointing approach is based on the refraction of a laser pulse in the presence of a strong radial density gradient in the breakdown of the tape with a small displacement of the femtosecond laser beam relative to the breakdown symmetry axis. A shift of several micrometers makes it possible to achieve beam deflection by an angle up to 10 degrees with acceptable beam charge and spectrum conservation. This opens up opportunities for in-situ applications for scanning objects with an electron beam and the multistage electron beam energy gain in consecutive laser accelerators without bulk magnetic optics for particles. Experimental findings are supported by numerical Particle-In-Cell calculations of laser-plasma acceleration and hydrodynamic simulations.Comment: Submitted to PPC

Biochemical aspects of magnesium-enhanced bone regeneration

Current research is focused on practical implications of magnesium-based implants largely due to their biodegradability and ability to promote bone healing and formation. However, the mechanism underlying the osteogenesis regulation by magnesium is still unclear.We describe cellular and molecular mechanisms underlying the effect of magnesium ions (Mg2+) on bone growth following the device implantation. The presented data demonstrate magnesium-induced activation of canonical Wnt/β-catenin signaling pathway in human bone marrow stromal cells resulting in their differentiation into osteoblasts, osteogenic effect and recovery of bone defects. We describe the role of the molecular mechanisms responsible for osteopromotive properties of Mg2+ and associated with unique transient receptor potential melastatin 7 (TRPM7) cation channels mediating the Mg2+ influx. TRPM7-mediated Mg2+ influx is important for platelet-derived growth factor (PDGF)-induced proliferation, adhesion, and migration of human osteoblasts, as well as for promotion of Mg2+-associated bone regeneration.We discuss the effect of Mg2+ on intracellular signaling processes, expression of the vascular endothelial growth factor (VEGF), hypoxia-inducible factor-2α, and peroxisome proliferator-activated receptor-γ coactivator 1α. Mg2+ can promote bone regeneration by enhancing the production of type X collagen and VEGF by osteogenic cells in bone marrow

Air Pollen Monitoring in a Specific Region as a Part of the Pollinosis Prevention

Background: The prevalence and severity of allergic diseases, including pollinosis, are increasing worldwide. Hay fever develops due to the complex interaction of genes and manifests itself due to exogenous factors. The main environmental etiology of allergy is plant pollen. Continuous study and analysis of the air pollen spectrum constitute the basis of air monitoring and are important in developing preventive measures for allergic diseases.   Objective: To perform an air pollen monitoring in Kr snodar and to assess the treatment of patients with pollinosis in various cities and districts of the Krasnodar Region according to the Krasnodar Regional Allergy Center data.   Materials and methods: We retrospectively analyzed the patients seeking medical care due to allergy in the Krasnodar Region using the statistical data obtained in 2022 from the Krasnodar Regional Allergy Center. We assessed the effects of air pollen pollution according to the data of air pollen monitoring in Krasnodar during the main activity of herbaceous plants’ taxa (from April 1, 2022 to October 31, 2022). We used AeRobiology and Microsoft Excel 2010 tools for data processing and development of the main parameters of the pollen season.   Results: According to the Krasnodar Regional Allergy Center data, there were 37,212 people diagnosed with J45.0, J46 and 20,012 people diagnosed with J30.1-30.4 in 2022. We identified 8 allergenic taxa of herbaceous plants in the Krasnodar air. We found that the total seasonal pollen concentration increased by an average of 1.8 in 2022 compared to previous monitoring periods in 2018-2021.   Conclusions: Comparative assessment of the prevalence of pollinosis and the air pollen monitoring are important for effective medical care

Analysis of Protein Markers in Plasma of Patients with Drug Dependence Syndrome: Observational Clinical Study

Background. In drug addiction treatment, the diagnostic process is based on the chemical toxicological determination of the intoxication substrate or its metabolite. Laboratory monitoring and prediction issues that could form the basis of secondary prevention remain unresolved. Specific nervous tissue proteins are considered to be the most promising laboratory markers of drug pathology.Objective — to determine some potential biomarkers of protein-chemical nature in the plasma of patients with drug dependence syndrome.Methods. The study was conducted according to the design of an observational clinical trial at the Narcological Dispensary of Krasnodar Krai in the period from 07.2021 to 07.2022. The main group (group 2) included 31 patients diagnosed with substance dependence syndrome. The control group (group 1, n = 15) consisted of healthy subjects submitted to occupational medical examinations. During the detoxification-stabilization therapy and rehabilitation, 5 proteins were determined in the plasma: brainand glial-derived neurotrophic factors, neuron-specific enolase, alpha-synuclein and calcium-binding protein S100B. Statistical analysis of the data involved the Mann-Whitney test for comparing the values of the control and experimental groups and the Wilcoxon test for comparing the values of one group obtained at different stages of observation. The calculations were carried out using StatPlus version 7 (AnalystSoft Inc., USA).Results. A total of 31 patients were included in the main group, 18 of them were followed up with a diagnosis of opioid dependence syndrome (n = 11) or psychostimulant dependence syndrome (n = 7). Patients dropped out of the study due to their refusal to participate in the study or undergo rehabilitation, or due to relapse of the disease. When admitted to the hospital, patients indicated a 45% decrease in brain-derived neurotrophic factor in the plasma ( p < 0.001), and a 3.9-fold decrease after rehabilitation course ( p < 0.001). Glial-derived neurotrophic factor in the plasma exceeded the controls 1.9 times ( p < 0.001) upon admission to hospital, but rapidly returned to normal values thereafter. Level of neuron-specific enolase in the plasma was also poor, 36% lower than the controls ( p <0.001), but approached the control values by the end of rehabilitation.Conclusion. The study obtained data indicating the changes in neurotrophic factors in the blood plasma of patients with opioid or psychostimulant dependence. The rehabilitation period was marked by a relatively rapid improving level of neurotrophins; however, brain-derived neurotrophic factor remained reduced despite the successful treatment, which may indicate the irreversible changes

The activity of NADPH-oxidase of neutrophilic leukocytes in patients with chronic generalized periodontitis in aggregate with iron - deficiency anemia

In patients with chronic generalized periodontitis in aggregate with iron-deficiency anemia revealed dysfunction of neutrophilic leukocytes caused by decreased activity of iron-containing components of antibacterial systems, in particular of NADPH-oxidase. Dental treatment of these patients is ineffective without the use of iron preparations

THE ELABORATION OF MODEL OF ACUTE PERIODONTITIS IN THE EXPERIMENT ON RATS

In connection with the search for new treatments of acute odontogenic inflammatory diseases, the elaboration of easily reproducible, accurate models of this disease in rats is actual. In the experiment on rats, the model of acute apical periodontitis followed by histopathological research was reproduced. The computer radiovisiography was held on the 5th day. The sampling of jaw with an involved tooth was carried out on the 21st day of the experiment. On the computer radioviziogramme and obtained histological blocks the pattern of acute purulent periodontitis were verified. On the 21st day of our experiment in the adjacent to the tooth bone a clear pattern of osteomyelitis was revealed. The experimental model that was investigated is easily replicable, pathologically verified. Its course is accompanied by the elaboration of complications in the form of acute odontogenic osteomyelitis