Probing the core of the strong nuclear interaction.

The strong nuclear interaction between nucleons (protons and neutrons) is the effective force that holds the atomic nucleus together. This force stems from fundamental interactions between quarks and gluons (the constituents of nucleons) that are described by the equations of quantum chromodynamics. However, as these equations cannot be solved directly, nuclear interactions are described using simplified models, which are well constrained at typical inter-nucleon distances1-5 but not at shorter distances. This limits our ability to describe high-density nuclear matter such as that in the cores of neutron stars6. Here we use high-energy electron scattering measurements that isolate nucleon pairs in short-distance, high-momentum configurations7-9, accessing a kinematical regime that has not been previously explored by experiments, corresponding to relative momenta between the pair above 400 megaelectronvolts per c (c, speed of light in vacuum). As the relative momentum between two nucleons increases and their separation thereby decreases, we observe a transition from a spin-dependent tensor force to a predominantly spin-independent scalar force. These results demonstrate the usefulness of using such measurements to study the nuclear interaction at short distances and also support the use of point-like nucleon models with two- and three-body effective interactions to describe nuclear systems up to densities several times higher than the central density of the nucleus.

[Methodical approach to the construction of the index of doctors' confidence in their activities].

INTRODUCTION: The COVID-19 pandemic has demonstrated the importance of developing a state policy to increase the attractiveness of a doctor's work and counteract professional burnout. The trust of doctors in their work determines the state of human resources in the field of healthcare. The development of an approach to the organization of monitoring the trust of doctors will allow identifying organizations at an early stage in which there is a decrease in the confidence of doctors in their activities. The purpose of the study is to develop and test a methodological approach to calculating the index of trust of doctors. MATERIALS AND METHODS: To construct the index, a list of statements was developed that are applicable for a comprehensive assessment of the doctor's activities. The approbation of the developed approach was carried out as part of a pilot sociological study in which 346 doctors from different regions of Russia took part. The significance of the statements used in the assessment was confirmed by binary probit regression. RESULTS: The analysis made it possible to calculate the index of doctors' trust for the obtained sample, equal to 62,5%. The results of the study can be used to assess the attitude of doctors to their activities both at the regional level and at the level of individual organizations. The Ministry of Health of the Russian Federation can use the results obtained to develop approaches to increasing the attractiveness of the medical profession to increase the public health of Russia.

Genetic damage in lymphocytes of lung cancer patients is correlated to the composition of the respiratory tract microbiome.

Recent findings indicate that the microbiome may have significant impact on the development of lung cancer by its effects on inflammation, dysbiosis or genome damage. The aim of this study was to compare the sputum microbiome of lung cancer (LC) patients with the chromosomal aberration (CA) and micronuclei (MN) frequency in peripheral blood lymphocytes. In the study, the taxonomic composition of the sputum microbiome of 66 men with untreated LC were compared with 62 control subjects with respect to CA and MN frequency and centromere fluorescence in situ hybridisation analysis. Results showed a significant increase in CA (4.11 ± 2.48% versus 2.08 ± 1.18%) and MN (1.53 ± 0.67% versus 0.87 ± 0.49%) frequencies, respectively, in LC patients as compared to control subjects. The higher frequency of centromeric positive MN of LC patients was mainly due to aneuploidy. A significant increase in Streptococcus, Bacillus, Gemella and Haemophilus in LC patients was detected, in comparison to the control subjects while 18 bacterial genera were significantly reduced, which indicates a decrease in the beta diversity in the microbiome of LC patients. Although, the CA frequency in LC patients is significantly associated with an increased presence of the genera Bacteroides, Lachnoanaerobaculum, Porphyromonas, Mycoplasma and Fusobacterium in their sputum, and a decrease for the genus Granulicatella after application of false discovery rate correction, significance was not any more present. The decrease of MN frequency of LC patients is significantly associated with an increase in Megasphaera genera and Selenomonas bovis. In conclusion, a significant difference in beta diversity of microbiome between LC and control subjects and association between the sputum microbiome composition and genome damage of LC patients was detected, thus supporting previous studies suggesting an etiological connection between the airway microbiome and LC.

Short/long-term cryopreservation prior to comet assay of whole-blood leukocytes and in vitro-cultured lung fibroblasts.

Single-cell gel electrophoresis (comet assay) is a valuable test that can be used in ecotoxicological, epidemiological, and biomonitoring contexts. We assessed the effects of short- (without cryopreservation) and long-term (with cryopreservation) storage of DMEM-cultivated human peripheral blood leukocytes (HPBLs) and a human lung fibroblast cell line (FLECH-104) on comet assay results. Samples were stored for 6 or 24 h at room temperature (23°Ð¡) or 4 °C and frozen at -80 °C or -196 °C for 1, 2, or 4 weeks. Short-term storage led to significant increases in the comet tail intensity (TI) and Olive tail moment (OTM) in HPBL and FLECH-104 samples. Freezing FLECH-104 samples at -80°Ð¡ and -196°Ð¡ resulted in TI mean increases, with no differences in OTM. All frozen HPBL samples did not exhibit significant increases in TI or OTM, and instead exhibited a slight decrease in TI versus the control at both -80 °C and -196 °C. Increased frequency of highly damaged cells was observed in FLECH-104 and HPBL cultures during both short-term storage and after freezing, which may indicate a significant destructive effect. Therefore, freezing of cell cultures and whole blood according to our protocol is not recommended.

[Limb-shaking transitory ischaemic attack in a patient with subocclusion of the internal carotid artery]. / Tranzitornaia ishemicheskaia ataka «limb shaking¼ u bol'nogo s subokkliuziei vnutrennei sonnoi arterii.

Described in the article is a clinical case report concerning symptomatic subocclusion of the internal carotid artery in a male patient with a rare variant of recurrent limb-shaking transitory ischaemic attacks (LS-TIA). The patient presented with a three-month history of episodes of involuntary jerky movements in his left hand. These episodes occurred invariably on assuming a vertical position. The findings of duplex scanning revealed subocclusion of the right internal carotid artery. The patient was subjected to stenting with the use of the system of proximal cerebral protection. The postoperative period was complicated by the development of cerebral hyperperfusion syndrome the risk of which in patients with LS-TIA is known to be elevated. Via telephone interviewing carried out at 1, 6 and 12 months after the intervention, the patient confirmed that the episodes of hand shaking did not recur. This case report highlights the importance of accurately assessing the clinical findings while selecting patients for carotid revascularization, since such ischaemic episodes are strongly suggestive of a severe lesion of the contralateral carotid artery. Once subocclusion is revealed, it is optimal to perform stenting with the use of a system of proximal protection, as a safer and more effective method of surgical revascularization in such conditions.

[The genetic diagnostics of mutations UGT1A1 in practice of modern medicine.]

The detection of mutations of the gene of UDF-glucuronyltransferase A1 (UGT1A1) has an important practical value. The carriers of mutant genotypes, mainly *28/*28, are characterized by a reduced function of glucuronidation and excretion of a number of endogenous and exogenous toxins. A precise association of particular forms of benign hyperbilirubinemia (especially Gilbert's syndrome) with mutations in promoter and exonic areas of UGT1A1 is established. On the other hand, carriers of various genotypes of UGT1A1 differ significantly in metabolism characteristics of a number of common medications (irinotecan, belinostat, etc.), that requires a dosage of these medications considering individual genetic status of patient. The analysis of modern technical solutions for genetic diagnostics of UGT1A1 mutations is carried out. The particular attention is paid to discussion of national developments for genetic typing of UGT1A1. The conclusion is made concerning small assortment of corresponding test-systems of Russian production. In some cases, there is no data about their main analytical and diagnostic characteristics. When developing design of diagnosticums, various methodological approaches are applied that allow to potential consumers to choose depending on financial technical capabilities of laboratory, amount of implemented analyses, qualification of personnel. To support UGT1A1 research instrumentally, laboratory equipment of national manufacturers can be sufficient that would permit to organize entire analytical cycle on the basis of import substitution principle.

[Ecological interpretation of higher units of steppe vegetation in southern mountains of Middle Siberia via quantitative ordination method].

Detrended correspondent analysis is used for constructing an ecological ordination model of higher units of steppe vegetation in southern mountains of Middle Siberia. The model is based on 326 complete geobotanical descriptions and correlation analysis between the values of major axes and climatic, soil-ground, and geographical parameters. In the space of two first principal ordination axes, ecological series of steppe vegetation coenofloras are observed which are orientated along climatic factors of annual and seasonal precipitation, temperature, oceanity-continentality, and ground stoniness. A syntaxonomic interpretation of observed ecological-geographical steppe types is given, and the hierarchy of higher classification units is substantiated from the ecological point of view.

[Retrograde type A aortic dissection after endovascular repair of the thoracic artery].

Retrograde type A aortic dissection is a severe and prognostically unfavourable complication of endovascular repair of the thoracic aorta. The aim of the present article is to describe a clinical case report concerning a hybrid operative intervention for retrograde type A aortic dissection in a patient having endured two-stage endovascular repair of the thoracic artery.

Composition of the sputum bacterial microbiome of patients with different pathomorphological forms of non-small-cell lung cancer.

Recent studies have shown that the bacterial microbiome of the respiratory tract influences the development of lung cancer. Changes in the composition of the microbiome are observed in patients with chronic inflammatory processes. Such microbiome changes may include the occurrence of bacteria that cause oxidative stress and that are capable of causing genome damage in the cells of the host organism directly and indirectly. To date, the composition of the respiratory microbiome in patients with various histological variants of lung cancer has not been studied. In the present study, we determined the taxonomic composition of the sputum microbiome of 52 patients with squamous cell carcinoma of the lung, 52 patients with lung adenocarcinoma and 52 healthy control donors, using next-generation sequencing (NGS) on the V3-V4 region of the bacterial gene encoding 16S rRNA. The sputum microbiomes of patients with different histological types of lung cancer and controls did not show significant differences in terms of the species richness index (Shannon); however, the patients differed from the controls in terms of evenness index (Pielou). The structures of bacterial communities (beta diversity) in the adenocarcinoma and squamous cell carcinoma groups were also similar; however, when analyzed according to the matrix constructed by the Bray-Curtis method, there were differences between patients with squamous cell carcinoma and healthy subjects, but not between those with adenocarcinoma and controls. Using the LEFse method it was possible to identify an increase in the content of Bacillota (Streptococcus and Bacillus) and Actinomycetota (Rothia) in the sputum of patients with squamous cell carcinoma when compared with samples from patients with adenocarcinoma. There were no differences in the content of bacteria between the samples of patients with adenocarcinoma and the control ones. The content of representatives of the genera Streptococcus, Bacillus, Peptostreptococcus (phylum Bacillota), Prevotella, Macellibacteroides (phylum Bacteroidota), Rothia (phylum Actinomycetota) and Actinobacillus (phylum Pseudomonadota) was increased in the microbiome of sputum samples from patients with squamous cell carcinoma, compared with the control. Thus, the sputum bacterial microbiome of patients with different histological types of non-small-cell lung cancer has significant differences. Further research should be devoted to the search for microbiome biomarkers of lung cancer at the level of bacterial species using whole-genome sequencing.

Sequential changes in gene expression profiles in breast cancers during treatment with the aromatase inhibitor, letrozole.

The study aim was to identify early (within 14 days) and late changes (by 3 months) in breast cancer gene expression profiles associated with neoadjuvant therapy with letrozole. RNA from sequential tumour biopsies in 54 patients was analyzed on microarrays; changes were determined by frequency, magnitude and significance analyses. Substantially more genes were changed at 3 months (1503) than at 14 days (237). Early changed genes were associated with cell cycle (downregulation), blood vessel development and extracellular matrix (upregulation); late changes included 'cellular metabolic process', 'generation of precursor metabolites and energy' (decreased) and 'cell adhesion' 'biological adhesion' (increased). A striking difference between the early and late changes was the general location of downregulated genes-nuclear structures at 14 days and mitochondria after 3 months. These changes in gene expression profiles provide a new and important database by which to understand molecular mechanisms of letrozole in breast cancers.

Theory of intercellular communication in the development of endothelial dysfunction.

Activation of intracellular signaling and blebbing of the plasma membrane lead to rafting and clustering of membrane receptors. Lymphocyte with high receptor density at the cell pole interacts with endothelial cells, which leads to their hyperactivation. In this case, lymphocyte getting a response from the endothelial cell can release membrane particles, which interact with endothelial receptors and penetrate through gaps between endothelial cells forming aseptic inflammation and causing atherogenesis. Endotheliocytes also contribute to generation of active membrane microparticles. Hyperactivation of endothelial cells and constant stimulation by the lymphocytes and microparticles trigger programmed cell death resulting in exfoliation of the endothelial cell. The endothelial defect is replaced by endothelial cells of the vascular wall (in case of mild endothelial dysfunction) or by progenitor endothelial cells (in case of severe dysfunction).

[Modulation of membrane blebbing and microparticle sheddimg as a target of cardiovascular prophylaxis].

Physicocemical and antigenic properties of peripheral blood lymphocytes and shed membrane microparticles were studied in patients with CHD and angina of effort and in those with hypertensive disease. The frequency of lymphocyte blebbing in CHD and angina patients was significantly higher than in those with HD (70.56, 52, 25.7% respectively). Incubation with rotenone and zymosan resulted in an increase of lymphocyte blebbing to 77.34 and 86.5% vs the initial level of 70.56% (p < 0.05). Patients of both groups had an increased number of membrane microparticles in peripheral blood (59.6 and 78.2 U/4 cm2 respectively). It is concluded that modulation of Imphocyte blebbing and microparticle shedding may be a promising target of cardiovascular prophylaxis.

[Stabilization of cellular membranes as a target of vascular therapy].

We present data of the study of effect of trimetazidine MB on the state of cellular membranes assessed on lymphocytes as highly sensitive model of hypoxia and endothelial dysfunction. Detection of external cytoplasmatic membrane blebbing and registration of quantity of membrane released microparticles by the method of phase-contrast microscopy were carried out in groups of patients with hypertensive disease without and with ischemic heart disease (IHD). It was found that number of cells in the state of terminal blebbing statistically significantly decreased and number of cells with intact cytoplasmic membrane increased at the background of intake of trimetazidine in all groups of patients. With correlation coefficient 0.76 (p<0.05) between content of membrane microparticles and terminal blebbing lowering of content of membrane released microparticles was noted in peripheral blood of patients of all studied groups. The investigation conducted allows to make conclusion that stabilization of cellular membranes is one of spectra of trimetazidine actions underlying improvement of self feeling of patients with vascular pathology.

[Role of repair gene polymorphism in estimating the sensitivity of human genome to radon in concentrations exceeding maximum permissible level].

The paper gives the results of investigating chromosome aberrations in human peripheral blood lymphocytes due to DNA repair genes, such as hOGG1, ADPRT, APE1, XRCC1, XpG, XpC, XpD, and NBS1, upon long-term exposure to excess indoor radon concentrations. The frequency of chromosome aberrations was found to be significantly lower in the carriers of the genotype hOGG1 326 Ser/Ser (versus the variant Ser/Cys), APE1 148 Asp/Asp (versus Val/Ala and Ala/Ala). The study polymorphic systems were shown to be of value in giving rise to individual types of chromosome aberrations (single fragments and chromosome exchanges).

Assessment of the State of Economic Security in Russia Using the Example of the Unemployment Rate Indicator: Fractal Analysis Method.

The article proposes methodological approaches to the verification of indicators of the state of the country's economic security using the method of fractal analysis. Fractal analysis technologies make it possible to determine the nature and dynamics of changes in the indicator, to verify its values (indicative or critical), and also to reveal the rate at which these states are reached on the time horizon of statistical observations. The unemployment rate indicator is selected as an example.

Polarized nonequilibrium Bose-Einstein condensates of spinor exciton polaritons in a magnetic field.

The effect of a magnetic field on a spinor exciton-polariton condensate has been investigated. A quenching of a polariton Zeeman splitting and an elliptical polarization of the condensate have been observed at low magnetic fields B<2 T. The effects are attributed to a competition between the magnetic field induced circular polarization buildup and the spin-anisotropic polariton-polariton interaction which favors a linear polarization. The sign of the circular polarization of the condensate emission at B<3 T is negative, suggesting that a dynamic condensation in the excited spin state rather than the ground spin state takes place in this magnetic field range. From about 2T on, the Zeeman splitting opens and from then on the slope of the circular polarization degree changes its sign. For magnetic fields larger than the 3 T, the upper spin state occupation is energetically suppressed and circularly polarized condensation takes place in the ground state.

[Genotoxic and cytotoxic effects in buccal cells of children living in ecologically different Kuzbass areas].

The article presents the results of the study of micronuclei and other types of cytogenetic aberrations in mucous tunic epithelium cells from children living in two different parts of the Kemerovo region (Tashtagol city, above-standard radon concentration exposition, n = 80), and Krasnoye settlement Leninsk-Kuznetsk area (comparison group, n = 41). The samples studied did not differ in the frequency of micronuclei containing cells. Tashtagol children sample showed significant increase in the number of binuclear cells, buccal epithelial cells with nuclear protrusions and with nuclear vacuoles, pyknotic cells, and apoptosis bodies. Reliable increase in average number of cells with chromatin condensation and kayolysis was found in the comparison group. It has been shown that the frequency of metaphase chromosome aberrations registered in peripheral blood lymphocytes corresponds to the amount of nuclear aberrations detected in buccal epithelium cells using micronuclei test.

[Toxic and genetic risk assessments in children of Gornaya Shoria].

This comprehensive study assessed a number of environmental factors that were potentially able to induce genotoxic effects in man. A set of radiological, physicochemical, and bioindication techniques was used to estimate the quality of water, air, and soil in the places of residence and education of children and adolescents from the boarding school of the town of Tashtagol and schoolchildren from the village of Krasnoye, Kemerovo Region. Excess radon levels in the air of living spaces and classes, a small excess of the maximum allowable concentration of gross forms of heavy metals in individual soil samples, and high toxic effects in the Drosophila gametes exposed to air samples were revealed in the Tashtagol children having higher genotoxic effects in the lymphocyte than those in the Krasnoye village ones. The findings suggest that the marked genotoxic effects recorded over a long time in the lymphocytes of children and adolescents living in Tashtagol may be associated with the complex influence of the above factors. It is north supplementing further investigations by an extended chemical analysis of water, air, snow, and soil samples taken in the places of residence and education of children.

Investigation of spin stiffness in spin-depolarized states of two-dimensional electron systems with time-resolved Kerr rotation.

An experimental technique based on time-resolved Kerr rotation allows a comparison of the spin stiffnesses of different spin-polarized and depolarized states in a two-dimensional electron system. With this technique, a new spin-correlated phase that has no known analogues was discovered. The new spin-depolarized phase is characterized by high spin stiffness equal to that of a spin-polarized quantum Hall ferromagnet.

Investigation of the genotoxic effects of fluoride on a bone tissue model.

Fluorides are thought to be a major cause of osteocarcinogenesis, due to their widespread industrial use, ability to accumulate in bone tissue, and genotoxic and probable carcinogenic properties. In vitro experiments investigating the genotoxic potential of fluorides in bone tissue models can provide valuable indirect information on their involvement in osteocarcinogenesis. Here, we investigated whether sodium fluoride (NaF) has the ability to induce DNA damage and chromosomal abnormalities in human osteosarcoma cells after 48 and 72 h of exposure. The cell cultures were treated with NaF in concentrations of 0, 20, 100 and 200 µg/ml. The level of DNA damage was assessed by the comet assay, and the frequency of chromosomal abnormalities by a micronucleus test. A significant increase in DNA damage indicators was noted in the samples treated with fluoride concentrations of 100 and 200 µg/ml, after 48 and 72 h of exposure. The micronucleus test revealed a dose-dependent increase in cells with micronuclei, nucleoplasmic bridges and nuclear protrusions. Increasing the concentration of NaF led to an increase in the prevalence of cytogenetic indicators after both treatment durations. This demonstrated ability of fluorine to exert genotoxic effects on bone cells indirectly indicates the possible importance of fluoride in the aetiology of osteosarcoma.