An experimental platform for investigation of the Zeeman effect in strong magnetic fields.

An experimental platform is developed for the investigation of the Zeeman effect in strong magnetic fields. Mega-Gauss magnetic fields are generated by a 1 MA Zebra pulsed power machine using metal rod loads. A gas jet or CH oil on the load is the source of hydrogen. Excited hydrogen atoms are backlit by black body radiation from the rod load. Hydrogen absorption spectra are recorded with a grating spectrometer and intensified gated CCD camera. The experimental platform enables the observation of the quadratic Zeeman effect in hydrogen gas jets using the spectral shift of the central line in the Zeeman triplet. Other gases can be studied using the gas jet method.

[Ankle replacement for severe post-traumatic deformation of the distal tibia: a case report]. / Endoprotezirovanie golenostopnogo sustava pri lechenii gruboi posttravmaticheskoi deformatsii distal'nogo otdela bol'shebertsovoi kosti. Klinicheskii sluchai.

OBJECTIVE: To evaluate the immediate results of ankle replacement with original prosthesis in a patient with severe post-traumatic deformation of the distal tibia. MATERIAL AND METHODS: When developing the original design of ankle prosthesis, we considered foreign analogues of classical and revision models of ankle prostheses taking into account their shortcomings. In this case, an integrated approach was used. Extensive work has been carried out to select materials for prosthetic components. Experimental work with mesenchymal stromal cells of bone marrow was aimed at testing cytotoxicity and biological compatibility. The staff of the department of designing biomechanical structures of the Research Institute of Bionics and Personalized Medicine of the Samara State Medical University carefully studied the proposed design of endoprosthesis using the Ansys software. After cadaver tests on full-scale models, we performed surgical intervention in a patient with severe post-traumatic deformity of the lower third of the left tibia. RESULTS: Our studies revealed convenience and certain advantages of intraoperative installation of original ankle prosthesis. Along with this, this clinical example indicated come features that must be taken into account in revision ankle replacement to avoid possible postoperative consequences. CONCLUSION: Original ankle prosthesis makes it possible to replace the distal tibia and preserve limb function.

Functional Phenotype of Alveolar Macrophages Features in Rats with Metabolic Syndrome.

Phenotypic characteristics of alveolar macrophages in the bronchoalveolar lavage fluid as well as their ability to acquire the M1 and M2 phenotypes during in vitro culturing with reprogramming factors were studied in rats with modeled diet-induced metabolic syndrome. A decrease in the number of alveolar macrophages with the M1 phenotype was found in animals with metabolic syndrome. The factors of metabolic syndrome do not affect phenotypic plasticity of cells in culture, but under the action of M2 reprogramming factors, the cells demonstrate a wide range of phenotypic plasticity by the CD80 and CD206 markers. The consistently high level of production of IL-6 and IL-10 by macrophages during culturing under different conditions indicates functional rigidity of the cells, which is probably a consequence of in vivo predetermined functional phenotype of these cells against the background of metabolic disorders.

Intracellular Lipid Levels and Oxidative Stress in Peripheral Blood Mononuclear Cells in Experimental Type 1 Diabetes Mellitus.

Type 1 diabetes mellitus was modeled in Wistar rats by intraperitoneal injection of streptozotocin (25 mg/kg for 5 days), which led to the appearance of the main symptoms of insulin-dependent diabetes. In peripheral blood mononuclear cells isolated by centrifugation on a Ficoll density gradient, the production of ROS and the level of intracellular lipids were evaluated by flow cytofluorimetry. In rats with type 1 diabetes mellitus, an increase in ROS levels in isolated peripheral blood monocytes, but not in the lymphocytic fraction was revealed. Incubation of isolated monocytes in a medium containing 1 mM oleic acid led to a 1.5-fold increase of intracellular lipid levels. After incubation of the lymphocyte fraction in this medium, no differences from the control were revealed. Disorders of carbohydrate and lipid metabolism in type 1 diabetes mellitus leading to an increase of free fatty acids and ROS levels can be detected ex vivo in isolated peripheral blood mononuclear cells.

[Biomechanics of the first metatarsophalangeal joint after replacement]. / Analiz biomekhaniki pervogo plyusnefalangovogo sustava posle endoprotezirovaniya.

OBJECTIVE: Analysis of biomechanics of the first metatarsophalangeal joint after arthroplasty, interaction between bones and two implants of the first metatarsophalangeal joint using skeletal model of the foot. MATERIAL AND METHODS: We developed anatomically adapted all-ceramic non-coupled endoprosthesis of proximal interphalangeal joint between 2016 and 2021. To create a model of the foot, we used diagnostic computed tomography whose images were applied in 3D sculpting system and computer-aided design system for final geometric modeling of the joint. RESULTS: In dorsal flexion of the first metatarsophalangeal joint under 45° with the presence of implant, cortical bone tissue can withstand a load of up to 40 kg. Cortical bone tissue with implant can withstand a load of up to 305 kg without dorsal flexion. Strength of implant elements made of zirconium ceramics significantly exceeds strength of bone tissue within implant-bone tissue connection. CONCLUSION: Postoperative axial load on the first metatarsophalangeal joint up to 35 kg with maximum dorsal flexion up to 45° is the most appropriate. Higher load and hyperextension over 45° may be followed by postoperative complications such as implant instability, dislocation and periprosthetic fracture.

Hypolypidemic Activity of L-Rhamnopyranosyl-6-O-Methyl-D-Galacturonan, a Polysaccharide Isolated from Birch Leaves (Betula pendula L.).

In male Syrian hamsters fed a synthetic high-fat diet enriched with cholesterol (0.3%), administration of a polysaccharide from birch leaves L-rhamnopyranosyl-6-O-methyl-D-galacturonan (3 g/100 g of diet) resulted in a decrease in total cholesterol levels, mainly due to the LDL fraction, triglycerides, and bile acids in blood serum; the content of triglycerides and cholesterol in the liver also decreased, while excretion of bile acids with feces increased. Thus, the lipid-lowering effect of L-rhamnopyranosyl-6-O-methyl-D-galacturonan is related to its ability to bind bile acids in the intestine and interrupt their enterohepatic circulation.

Anti-Atherosclerotic Action of a New Stimulator of Soluble Guanylate Cyclase in an Experiment.

We studied the effect of an indolinone derivative GRS on the development of experimental atherosclerosis in C57BL/6 mice. Atherosclerosis was modeled by intraperitoneal administration of endothelial lipoprotein lipase inhibitor Kolliphor P 407 micro Geismar over 5 months. GRS was administered orally in a dose of 10 mg/kg once a day throughout the experiment. In 5 months, the levels of total cholesterol, LDL, and triglycerides in blood serum, as well as histological composition of the ascending aorta were studied. In mice with experimental atherosclerosis, we observed pronounced dyslipidemia with an increase in serum cholesterol, LDL, and triglycerides and accumulation of xanthoma cells in the aorta wall. Repeat administration of GRS did not eliminate dyslipidemia, but prevented an increase in the number of xanthoma cells in the aorta wall (p<0.05). The stimulator of soluble guanylate cyclase GRS did not exhibit hypolipidemic activity, but restored impaired endothelial function in the atherosclerosis model and prevented atherosclerotic damage to blood vessels and vascular wall remodeling.

Quadratic Zeeman effect in hydrogen at 2-3 MG magnetic fields.

The Zeeman effect is used for measurement of magnetic fields in astrophysical and laboratory plasmas. Magnetic fields in atmospheres of magnetic white dwarf stars are in the range 40 kG-1 GG. The quadratic Zeeman effect results in the additional split and shift of lines for magnetic fields >2 MG. Hydrogen Balmer lines were studied in magnetic fields delivered by a 1 MA pulse power generator. The magnetic field was generated by rod loads 0.8-1 mm in diameter. A droplet of CH oil on the load center was the source of hydrogen. A low ionized oil layer was backlit by blackbody emission from the rod with a temperature of 0.5-0.6 eV. Zeeman splitting of H-alpha and H-beta absorption lines were with a grating spectrometer. A spectral shift of the central component of the triplet indicated the quadratic Zeeman effect in hydrogen lines.

Airway Smooth Muscles Contractions in Metabolic Syndrome.

We studied contractile responses of isolated airway smooth muscle segments from rats with metabolic syndrome. Metabolic syndrome was induced in rats by high-fat and high-carbohydrate diet. It was shown that metabolic syndrome was associated with an increase of bronchoconstrictor action of cholinergic receptor activator carbacholine (0.1-100 µM) and a decrease of the dilatory effect of ß2-adrenoreceptor activator salbutamol (0.1-100 µM). The observed effects of agonists are epithelium-dependent. Disorders in contractile activity in the airway smooth muscles were accompanied by bronchial epithelium destruction, immune inflammation in the bronchial wall, muscular and peribronchial adipose tissue hypertrophy.

Insulin Resistance in Experimental Type 1 Diabetes Mellitus.

Experimental type 1 diabetes mellitus (T1DM) was induced in rats by daily intraperitoneal injections of alloxan in a dose of 90 mg/kg for 4 days. For verification of insulin resistance, insulin tolerance test was performed in 2 weeks and the glucose utilization rate constant (KITT) was calculated. The rats demonstrated the main symptoms of T1DM: hypoinsulinemia, hyperglycemia, ketonemia, glucosuria, ketonuria, polydipsia, polyphagia, weight loss, and insulin resistance, as evidenced by a decrease in KITT. The serum content of free fatty acids and triacylglycerols significantly increased. The content of triacylglycerols increased in skeletal muscles and decreased in the liver. A negative linear correlation was found between KITT and triacylglycerol content in muscles. Thus, the development of insulin resistance in experimental T1DM in rats is associated with accumulation of triacylglycerols in skeletal muscles.

Development and integration of photonic Doppler velocimetry as a diagnostic for radiation driven experiments on the Z-machine.

Plasma density measurements are key to a wide variety of high-energy-density (HED) and laboratory astrophysics experiments. We present a creative application of photonic Doppler velocimetry (PDV) from which time- and spatially resolved electron density measurements can be made. PDV has been implemented for the first time in close proximity, ∼6 cm, to the high-intensity radiation flux produced by a z-pinch dynamic hohlraum on the Z-machine. Multiple PDV probes were incorporated into the photoionized gas cell platform. Two probes, spaced 4 mm apart, were used to assess plasma density and uniformity in the central region of the gas cell during the formation of the plasma. Electron density time histories with subnanosecond resolution were extracted from PDV measurements taken from the gas cells fielded with neon at 15 Torr. As well, a null shot with no gas fill in the cell was fielded. A major achievement was the low noise high-quality measurements made in the harsh environment produced by the mega-joules of x-ray energy emitted at the collapse of the z-pinch implosion. To evaluate time dependent radiation induced effects in the fiber optic system, two PDV noise probes were included on either side of the gas cell. The success of this alternative use of PDV demonstrates that it is a reliable, precise, and affordable new electron density diagnostic for radiation driven experiments and more generally HED experiments.

Anti-Adhesion Effect of Composite Film Materials Based on Glycoluril-Modified Sodium Carboxymethyl Cellulose.

The aim of the study was to develop composite film materials derived from modified sodium carboxymethyl cellulose and to evaluate their anti-adhesive effects. Materials and Methods: The modified film materials were obtained by dissolving sodium carboxymethyl cellulose (Na-CMC) in an aqueous solution of a modifier (glycoluril) with subsequent homogenization and drying in a vacuum drying oven at room temperature. Physicomechanical parameters of the obtained films were determined using the Instron 3369 universal electromechanical testing machine (Great Britain) equipped with a climatic chamber (300-523 K), improved video extensometer, and the MKC-25 micrometer (Russia). Cytotoxicity of glycoluril-modified film materials derived from Na-CMC was studied by incubating cell cultures of 3T3-L1 mouse fibroblasts directly with extracts from films under study using a colorimetric test. Their anti-adhesion effect was investigated on 40 female Wistar rats by modeling a flat adhesion by inducing abrasion of the cecum and suturing the deserosed surface of the abdominal wall anatomically opposite the abrasion area. The presence of adhesions was assessed on day 8 after the operation. Commercial membrane Seprafilm (USA) was used as a reference sample. Results: It was found that extracts obtained from film materials derived from Na-CMC modified with glycoluril at a concentration of 0.01 and 0.05 wt. % had no cytotoxic effect on the cell culture of mouse fibroblasts 3T3-L1. Flat adhesions were not detected when using Seprafilm. When film materials under study were placed in the abdominal cavity between the injured areas, formation of flat adhesions was not observed or observed in one case out of ten. Conclusion: The obtained films are promising for preventing adhesions as a barrier-type agent. Modifying Na-CMC with glycoluril made it possible to create films that prevent formation of flat adhesions, have improved physical and mechanical properties and no cytotoxic effect.

Role of H2S in Regulation of Vascular Tone in Metabolic Disorders.

We studied the effect of the H2S donor (NaHS, 1-500 µM) on the contractile responses of isolated aortic smooth muscle segments from rats with metabolic syndrome induced by high-fat, high-carbohydrate diet. It was found that the vasorelaxing effect of NaHS (5-100 µM) decreased in under conditions of MS. The endothelial NO synthase inhibitor L-NAME (100 µM) suppressed the effect of NaHS, while cystathionine-gamma-lyase inhibitor PAG (100 µM) decreased the vasodilating effects of acetylcholine (0.1-100 µM). Application of endogenous NO precursor L-arginine (1 mM) potentiated in the effects of H2S donor NaHS. Thus, the contractile activity of vascular smooth muscles in metabolic syndrome is determined by not only the effect of H2S, but also the influence of NO.

Radiolabeled Complex of Antimicrobial Peptides UBI29-41 and UBI18-35 Labeled with 99mTc for Differential Diagnosis of Bone Infection of the Limbs.

We studied an original radiolabeled complex of antimicrobial peptides UBI29-41 and UBI18-35, ubiquicidin derivatives, for distinguishing between bacterial and aseptic inflammation. For radiolabeling of the peptides with technetium-99m, a bifunctional chelating agent succinimide-1-yl 6-(bis(pyridin-2-ylmethyl)amino)hexanoate was used. The obtained complexes 99mТс-DPAH-UBI29-41 and 99mТс-DPAH-UBI18-35 had radiolabeling yield >80% and radiochemical purity >96%. Accumulation of the complexes in the focus of bacterial inflammation in bone structures and the absence of this complex in the site of aseptic inflammation was confirmed in a rat model of traumatic osteomyelitis by single-photon emission computed tomography.

A study of kudurs used by wild animals located on the water sources high in REE content in the Caucasus Nature Reserve.

One of the theories explaining the reasons for geophagy, which was proposed earlier by the authors of the article, consists in the assumption that animals need rare-earth elements (REE). In order to test this hypothesis, we studied the chemical composition of spring waters in the territory of the Caucasus Nature Reserve at three kudurs along the Achipsta River, as well as at the Mamaevsky kudur (southwestern slope of the Pshekish mountain). At the Mamaevsky kudur, we also studied the chemical composition of earth consumed by animals, and the species, age and gender composition, seasonal and daily activity of ungulate animals-visitors of the kudur. It was determined that the most active visitors of the Mamaevsky kudur were European bison (Bison bonasus) with one activity peak during the rut, in July. The frequency of visits to the kudur by red deer (Cervus elaphus) was 4 times lower with the highest peak activity in April and a lower peak in August. Only in one of four water sources at the Mamaevsky kudur there was an elevated concentration of Na (by 7 times). In the other three the concentration was comparable to the local river water. The waters of two "sodium-free" springs had increased concentrations of REE (by 5-8 times). Geophagic earths near the Mamaevsky springs are decomposition products of siltstone and sandstone shale rocks of the Jurassic age consisting of clay minerals (illite mixed with smectite, and chlorites)-from 42 to 45%, and quartz and feldspar (in total up to 50%) mixed with Fe and Ca carbonates. The chemical composition of acid extracts (0.1 N HCl, pH = 1.0) from consumed earth showed the highest extractability of Ca and Fe. In trace elements, Sr, Ba, Zn, Cu, Ni, Co, V, light lanthanides, and Y are most actively extracted. Na is extracted at 0.03-0.1 g/kg. The sodium bicarbonate spring water consumed by animals at kudurs on the Achipsta River had Na contents 70-300 times, and REE contents 25-40 times higher than that in the river water. The revealed facts do not contradict the hypothesis that the desire for geophagy in animals in the Caucasus (in addition to the long-known "urge" for Na) can be also related to the properties of lanthanides group elements exchange in the body.

Cold and distant: structural features of the nucleoprotein complex of a cold-adapted influenza A virus strain.

Two influenza A nucleoprotein variants (wild-type: G102R; and mutant: G102R and E292G) were studied with regard to macro-molecular interactions in oligomeric form (24-mers). The E292G mutation has been previously shown to provide cold adaptation. Molecular dynamics simulations of these complexes and trajectory analysis showed that the most significant difference between the obtained models was distance between nucleoprotein complex strands. The isolated complexes of two ribonucleoprotein variants were characterized by transmission electron microscopy and differential scanning fluorimetry (DSF). Presence of the E292G substitution was shown by DSF to affect nucleoprotein complex melting temperature. In the filament interface peptide model, it was shown that the peptide corresponding in primary structure to the wild-type NP (SGYDFEREGYS) is prone to temperature-dependent self-association, unlike the peptide corresponding to E292G substitution (SGYDFGREGYS). It was also shown that the SGYDFEREGYS peptide is capable of interacting with a monomeric nucleoprotein (wild type); this interaction's equilibrium dissociation constant is five orders of magnitude lower than for the SGYDFGREGYS peptide. Using small-angle neutron scattering (SANS), the supramolecular structures of isolated complexes of these proteins were studied at temperatures of 15, 32, and 37 °C. SANS data show that the structures of the studied complexes at elevated temperature differ from the rod-like particle model and react differently to temperature changes. The data suggest that the mechanism behind cold adaptation with E292G is associated with a weakening of the interaction between strands of the ribonucleoprotein complex and, as a result, the appearance of inter-chain interface flexibility necessary for complex function at low temperature.Communicated by Ramaswamy H. Sarma.

Regulation of Vascular Smooth Muscle Contractions in the Model of Metabolic Syndrome.

Reduced glucose tolerance, hyperglycemia, and imbalance in lipid levels were found in rats with metabolic syndrome induced by a high-fat, high-carbohydrate diet. The contractile responses of intact and endothelium-denuded aortic smooth muscle segments from rats with metabolic syndrome to application of acetylcholine, phenylephrine, sodium nitroprusside, and forskolin were studied by mechanographic method. It was found that endothelial dysfunction develops against the background of metabolic and hemodynamic disorders in metabolic syndrome. It was shown that the regulation of vasoconstrictor reactions of vascular smooth muscles in metabolic syndrome is due to a decrease in Ca2+ entry, mainly voltage-independent, as well as changes in the function of cGMP- and cAMP-activated K+-channels.

Complex study of air pollution in electroplating workshop.

A comprehensive analysis of the state of air inside an industrial workshop with electroplating production was carried out. The data of quantitative distribution of suspended particles by size fractions (PM0.3, PM0.5, PM1, PM3, PM5, PM10) are presented for 15 main processes of electroplating. Morphometric and chemical composition of the surface of particles were studied. We observed particles of rounded shape, various agglomerates with complex geometric shapes, acute-angular particles, which when inhaled pose a maximum threat to human health. Chemical analysis of these particles showed an absolute predominance of oxides of non-ferrous metals, the percentage of which varied depending on the type of electroplating bath. The content of highly hazardous substances of the 1st (Zn, Pb, and Cd) and the 2nd (Cu, Cr, Ni, Co, and Mo) hazard classes in each sample was recorded.

[Zn-CysHis Protein Factor Families: Role of Electrostatic Interaction of Zn-Domains in Factor Functions].

The large amount of the DNA- and RNA-binding protein regulatory factors contain Zn-domains. Total six Zn-CysHis factor families with different functions were considered. Among them the transcription factors of family PF00096, complex type Zn-Cys2His2, is the most important because it includes over 340.000 members of 365.000 total members listed at present in the Zn-containing factor families. The role of electrostatic potential of Zn-domains in the structure and function of factors from different factor families has been considered. We have shown that the positive electrostatic potential of Zn-domains plays an essential role in forming contact of factors' Zn-domains with DNA/RNA in three protein factor families PF00096, PF12874, and PF09329. While in other three families PF03119, PF08996, and PF01258 Zn-domains do not contact with nucleic acids, and electrostatic interactions do not play a distinctive role, consequently.

[Relationship between masticatory muscles activity and motor cortex activation during treatment of patients with distal malocclusion]. / Vzaimosviaz' izmeneniia aktivnosti zhevatel'nykh myshts i motornykh zon kory golovnogo mozga pri lechenii patsientov s distal'noi okkliuziei.

The processes of neuroplasticity of the motor cortex of the brain were evaluated in the treatment of 20 (12 women and 8 men) patients aged 18-35 years (22.5±1.5 years) with distal occlusion using functional magnetic resonance imaging (fMRI), as well as comparison of surface myography (EMG) data to assess the adaptive capabilities of the tooth-jaw system and the central nervous system against the background of orthodontic correction. Correction of distal occlusion was carried out using ceramic braces 'Damon' (f. 'Ormco', USA). The advancement of the lower jaw forward with bite enhancement was carried out using the Twin force device ('Ortho Orgonizers GmbH', Germany). The study was conducted in five stages: 1) before orthodontic correction; 2) before installing the Twin force device; 3) after anterior displacement of the lower jaw and bite enhancement on the Twin force device; 4) after removing the brackets; 5) 1.5 months after the treatment. FMRI proved to be a useful tool for orthodontic treatment efficacy assessment and neuromuscular adaptation of maxillofacial structures to changing functional status.