Theoretical Investigation of Molecular and Electronic Structures of Buckminsterfullerene-Silicon Quantum Dot Systems.

Density functional theory (DFT) and density functional tight binding (DFTB) molecular dynamics (DFTB/MD) simulations of embedding and relaxation of buckminsterfullerene C60 molecules chemisorbed on (001) and (111) surfaces and inside bulk silicon lattice were performed. DFT calculations of chemisorbed fullerenes on both surfaces show that the C60 molecule deformation was very small and the C60 binding energies were roughly ∼4 eV. The charge analysis shows that the C60 molecule charges on (001) and (111) surfaces were between -2 and -3.5 electrons, respectively, that correlates well with the number of C-Si bonds linking the fullerene molecule and the silicon surface. DFT calculations of the C60 molecule inside bulk silicon confirm that the C60 molecule remains stable with the deformation energy values of between 11 and 15 eV for geometries with different C60 configurations. The formation of some C-Si bonds causes local silicon amorphization and corresponding electronic charge uptake on the embedded fullerene cages. Charge analysis confirms that a single C60 molecule can accept up to 20 excessive electrons that can be used in practice, wherein the main charge contribution is located on the fullerene's carbon atoms bonded to silicon atoms. These DFT calculations correlate well with DFTB/MD simulations of the embedding process. In this process, the C60 molecule was placed on the top of the Si(111) surface, and it was further exposed by a stream of silicon dimers, resulting in subsequent overgrowth by silicon.

[Frequency of Ponticulus posticus and Ponticulus lateralis in patients admitted to hospital with traumatic brain injur]. / Vstrechaemost' (chastota) zadnikh i lateral'nykh mostikov anomalii Kimmerle u bol'nykh, postupivshikh v statsionar s cherepno-mozgovoi travmoi.

OBJECTIVE: To determine the frequency of Ponticulus posticus and Ponticulus lateralis among patients admitted to a24-hour emergency hospital. MATERIAL AND METHODS: The study included 2887 patients with a traumatic history who were admitted to the hospital for emergency reasons. This principle of sampling allowed us to exclude a high concentration of studies of patients with chronic neurological diseases, the cause of which could be symptomatic Kimmerle's anomaly (KA). During the period 01.01.20 to 31.12.20, primary CT was performed on an emergency basis in 7348 patients. Of these, CT scans of the brain and cervical spine were performed in 2965 patients. Some patients (78 people) were excluded from the study due to the presence of cervical vertebral fractures and metal artifacts in the craniovertebral region. RESULTS: The Ponticulus posticus was detected in 1162 (40.2%) patients, among them class 3 and 4 was detected in 27.7%, and class 2 ossification in 12.5%. This Ponticulus posticus was significantly more common (χ2 test, p=0.0005) in men. The Ponticulus lateralis was identified in 231 patients (8%), among them 94 patients (3.3%) had complete ponticulus on both sides, 29 patients (1%) - on one side, and 108 patients (3.7%) - two-sided incomplete ponticulus. In patients with class 2-3-4, Ponticulus lateralis were detected significantly more often (χ2 test, p<0.0001). CONCLUSION: The cumulative incidence of KA was 42%, 17% of patients are carriers of a complete KA bridge, which is significantly higher than in the European or Asian regions. The data suggest that KA is not the result of ossification of the posterior atlanto-occipital membrane, since different classes of KA occur equally often at different ages. Further studies of KA are needed, including its occurrence in patients of the neurological department and its correlation with individual neurological syndromes to determine the need for surgical treatment in the population.

[School of the rational nutrition for children and adolescents with obesity].

The article presents the principles of the classes organizations in the school of the rational nutrition for children and adolescents with overweight and obesity, and also for their parents. The school consists of six interactive lessons, which explains the negative consequences of obesity, understand the basic principles of optimal diet. Each class has "minilections", that adapted for both children and parents and accompanied by interactive dialogues, which are attended by all family members of children who are overweight or obese. Presented own observational data for 20 families that attended school. A positive result was achieved in 15 families. The article analyzes the reasons that didn't lead to the expected result in 5 families.

[First case of thrombolysis with non-immunogenic staphylokinase in a patient with ischemic stroke receiving dabigatran etexilate followed by thrombectomy]. / Pervyi sluchai tromboliticheskoi terapii pri pomoshchi neimmunnogennoi stafilokinazy u patsientki s ishemicheskim insul'tom, poluchayushchei dabigatrana eteksilat, s posleduyushchei trombektomiei.

Currently, five oral anticoagulants have been shown to be effective in preventing recurrent ischemic stroke and/or systemic embolism in patients with non-valvular atrial fibrillation. However, 1.1-2.2% of patients taking oral anticoagulants develop ischemic strokes. The use of oral anticoagulants limits the possibility of systemic thrombolytic therapy, as this is associated with an increased risk of symptomatic hemorrhagic transformation. The exception is cases when, with the help of a specific antagonist, it is possible to neutralize the effect of the anticoagulant in the shortest possible time and achieve normocoagulation. Currently, the Russian Federation allows two drugs for systemic thrombolytic therapy in patients with ischemic stroke in the «therapeutic window¼ up to 4.5 hours from the onset of the disease - recombinant tissue plasminogen activator and non-immunogenic staphylokinase, which showed no less efficacy and safety in the FRIDA study compared to recombinant tissue plasminogen activator. This article describes a clinical case of the first systemic thrombolytic therapy with a non-immunogenic staphylokinase after the use of idarucizumab in a patient taking dabigatran etexilate, followed by thrombectomy.

[Obesity in childhood].

In this article presented modern data on the definition of obesity in childhood and its prevalence. Were reflected the basic diagnostic criteria for obesity and metabolic syndrome. Were analyzed genetic changes, hormonal factors, influence lifestyle of modern man as the reasons of the obesity. Are also was considered data on the relation of obesity and its complications such as cardiovascular, metabolic syndromes, nonalcoholic fatty liver disease. Was reflected the views of various specialists (cardiologists, endocrinologists, gastroenterologists, pediatricians) to the problem of overweight and obesity in children and adolescents. Were presented modern data on the approaches to the treatment of obesity in children.

[The use of amantadine sulfate in ischemic stroke]. / Primenenie amantadina sul'fata pri ishemicheskom insul'te.

OBJECTIVE: To assess the efficacy and safety of amantadine sulfate in patients with ischemic stroke. MATERIAL AND METHODS: Ninety five patients with ischemic stroke were randomized within 120 hours from the onset of symptoms into two groups: patients of the main group received amantadine sulfate (400 mg/day intravenously) for 4 days, followed by oral administration at 400 mg/day for 6 days; the comparison group received standard therapy according to the order of the Ministry of Health of the Russian Federation No. 928n. The observation period for the patients was 90 days. The main indicators of treatment efficacy were: Glasgow Coma Scale (GCS), Modified Rankin Scale (mRS), Bartel Index (BI), National Institutes of Health Stroke Scale (NIHSS), and mortality. Any side effects were recorded to assess safety. RESULTS AND CONCLUSION: There were no statistically significant differences between the main group and the comparison group for the main parameters. However, we observed better results in patients with mild stroke (NIHSS <13 points) and atherothrombotic pathogenetic variant of ischemic stroke. This observation should be confirmed in subsequent clinical studies.

[Immuno-morphologic detection of specific APO-B antigenic determinants in normal intima and atherosclerotic plaques in the human aorta]. / Immunomorfologicheskoe vyiavlenie otdel'nykh antigennykh determinant apoB v normal'noi intime i ateroskleroticheskikh bliashkakh aorty cheloveka.

Various apo-B antigenic determinants exposures in the normal aortic intima and atherosclerotic plaques were examined by immunofluorescence using 5 clones from monoclonal antibodies (BAb) to apo-B. As a rule, 4 clones were found to react with apo-B in the normal aortic intima, whereas the clone 12G10 failed to respond to it. All the 5 determinants of apo-B were exposed in the fibrous tissue of most atherosclerotic plaques. However, there were atherosclerotic plaques, in whose fibrous tissue only did 1 to 3 clones positively react with apo-B. The similar expression of apo-B antigenic determinants was observed in the atheronecrotic zone of fibrous plaques. Apo-B did not respond to apo-B MAb at all in some atherosclerotic plaques present in the zone of atheronecrosis. Whether it is possible to modify low-density lipoproteins just in the arterial wall, especially in atherosclerotic plaques and whether this process is significant in the pathogenesis of atherosclerosis are discussed in the paper.

[Proliferative mucosal changes of the corpus and cervix uteri in women using intrauterine contraceptives]. / Proliferativnye izmeneniia slizistoi obolochki tela i sheiki matki u zhenshchin, primeniaiushchikh vnutrimatochnye kontratseptivy.

The paper discusses the incidence and peculiarities of proliferative changes in cervical and uterine mucosa of women with a record of using polyethylene intrauterine contraceptives (Lipps' loop) under 12 years. Intrauterine contraception is not conducive to a rise in the frequency of either precancer or cancer of the uterine cervix; nor is it responsible for endometrial malignancies.

[Use of a rating system in the assessment of 4th-year students' knowledge of obstetrics]. / Ispol'zovanie reitingovoi sistemy otsenki znanii studentov pri prepodavanii akusherstva na IV kurse.

The rating system was used to check up students' knowledge in obstetrics at the fourth course of the therapeutic and prophylactic faculty. Comparison of the results of the rating system and the routine one evidence that introduction of the new system has essentially improved the attendance of practical studies by the students, and their mean marks were improved as well. Students' knowledge assessed by the rating system coincided with the assessment made during examinations, thus permitting the use of this system in future without resorting to traditional sessions of examinations.