Phase transitions on the surface of a carbon nanotube

A suspended carbon nanotube can act as a nanoscale resonator with remarkable electromechanical properties and the ability to detect adsorption on its surface at the level of single atoms. Understanding adsorption on nanotubes and other graphitic materials is key to many sensing and storage applications. Here we show that nanotube resonators offer a powerful new means of investigating fundamental aspects of adsorption on carbon, including the collective behaviour of adsorbed matter and its coupling to the substrate electrons. By monitoring the vibrational resonance frequency in the presence of noble gases, we observe the formation of monolayers on the cylindrical surface and phase transitions within these monolayers, and simultaneous modification of the electrical conductance. The monolayer observations also demonstrate the possibility of studying the fundamental behaviour of matter in cylindrical geometry.Comment: Unpublished; 7 pages with 4 figures plus 3 pages of supplementary materia

MULTIPROCESSOR MODELING TECHNOLOGIES FOR THE APPLIED STATISTICAL TASKS

The work considers the multiprocessors technologies of modeling for Monte Carlo tasks. It is shown that only application of the modern super productive systems permitted the new way to realize the mechanism of corresponding partitioned computations. The calculating schemes that supply to provide the increase of productivity and calculations' speed effectiveness are shown. In this article the modified algorithm of parallel calculations is offered based on the Monte Carlo method. Here every calculator has its own random generator of numbers. Thus intermediate calculations come true independently on the different, separately taken blades of cluster, "calculators". The results are already processed on some separately taken master -blades ("analyzer"). This allows to get rid from the necessary presence of router-communicator between the random generator of numbers and "calculator". Obviously, that such decision allows to accelerate the process of calculations. It is shown that the parallel algorithms of the Monte Carlo method are stable to any input data and have the maximal parallel form and, thus, minimal possible time of realization using the parallel computing devices. If it is possible to appoint one processor to one knot of calculation. Thus the realization of calculations becomes possible in all knots of net area in parallel and simultaneously.The work considers the multiprocessors technologies of modeling for Monte Carlo tasks. It is shown that only application of the modern super productive systems permitted the new way to realize the mechanism of corresponding partitioned computations. The calculating schemes that supply to provide the increase of productivity and calculations' speed effectiveness are shown. In this article the modified algorithm of parallel calculations is offered based on the Monte Carlo method. Here every calculator has its own random generator of numbers. Thus intermediate calculations come true independently on the different, separately taken blades of cluster, "calculators". The results are already processed on some separately taken master -blades ("analyzer"). This allows to get rid from the necessary presence of router-communicator between the random generator of numbers and "calculator". Obviously, that such decision allows to accelerate the process of calculations. It is shown that the parallel algorithms of the Monte Carlo method are stable to any input data and have the maximal parallel form and, thus, minimal possible time of realization using the parallel computing devices. If it is possible to appoint one processor to one knot of calculation. Thus the realization of calculations becomes possible in all knots of net area in parallel and simultaneously

CLINICAL EFFICACY AND SAFETY OF ADEMETIONINE IN PATIENTS WITH DIABETES-ASSOCIATED OSTEOARTHRITIS: A CROSS-OVER PILOT STUDY

Osteoarthritis (OA) is one of most common rheumatic diseases, and currently there is no effective pharmacological treatment of OA. It has been suggested that lack of effective treatment is, in part, due to the disease heterogeneity which may lead to development of several OA subtypes (phenotypes). Diabetes-associated OA is among the proposed OA phenotypes. The key mechanism involved into inflammatory and degenerative changes in OA is a decrease in DNA methylation suggested for several cell types, that was also demonstrated in type 2 diabetes mellitus. Therefore, pharmacological increase of DNA methylation may be an effective treatment strategy which may exert pleiotropic effects in diabetes-associated OA. In a randomized crossover study, we have evaluated efficacy and safety of ademetionine, a methyl group donor, in comparison with chondroitine sulfate in patients with OA associated with type 2 diabetes mellitus. The patients were randomly assigned to sequential treatment of chondroitine sulfate/ademetionine or ademetionine/chondroitine sulfate during one month, with a washout period of 2 weeks. The primary endpoint was pain measured according to visual analogue scale (VAS). Painful symptoms, as well as function and disease signs in knee, hip and hand joints were also assessed with KOOS, WOMAC, and FIHOA scales. General performance was assessed with SF–36 scale. To evaluate systemic inflammation, we measured serum IL-6, IL-18, adiponectin, and CRP using ELISA technique. Concentrations of serum cartilage destruction biomarkers (aggrecan and antibodies to collagen type II) were assessed by ELISA. Serum lipid levels were measured with standard method; glycated hemoglobin was assessed with liquid chromatography. Ten patients (all women, age 61.7-74.2 year with BMI of 1.1-38.4 kg/m2) were included in the study. It has been demonstrated that ademetionine showed a statistically significant analgetic effect (decrease in VAS pain), improved knee function and reduced symptoms in knee joints (as measured by KOOS subscales), and did not influence the levels of systemic inflammation or cartilage destruction biomarkers. There was also no change in lipid levels and glycated hemoglobin concentrations. Ademetionine was well tolerated, no serious adverse events occurred during the treatment. In conclusion, ademetionine does not have pleiotropic pharmacological effects in diabetes-associated OA. Its potential application in cases of different comorbidities requires further studies

Coupling carbon nanotube mechanics to a superconducting circuit

The quantum behaviour of mechanical resonators is a new and emerging field driven by recent experiments reaching the quantum ground state. The high frequency, small mass, and large quality-factor of carbon nanotube resonators make them attractive for quantum nanomechanical applications. A common element in experiments achieving the resonator ground state is a second quantum system, such as coherent photons or superconducting device, coupled to the resonators motion. For nanotubes, however, this is a challenge due to their small size. Here, we couple a carbon nanoelectromechanical (NEMS) device to a superconducting circuit. Suspended carbon nanotubes act as both superconducting junctions and moving elements in a Superconducting Quantum Interference Device (SQUID). We observe a strong modulation of the flux through the SQUID from displacements of the nanotube. Incorporating this SQUID into superconducting resonators and qubits should enable the detection and manipulation of nanotube mechanical quantum states at the single-phonon level

Cytoprotective effect of non-opioid leu-enkephalin analogue in primary culture of pulmonary fibroblasts in oxidative stress

Aim. Analysis of the cytoprotective effect of non-opioid leu-enkephalin analogue (Phe-D-Ala-Gly-Phe-Leu-Arg) in the primary culture of pulmonary fibroblasts in conditions of oxidative stress. Methods. Pulmonary fibroblasts were incubated with the peptide of non-opioid leu-enkephalin analogue (Phe-D-Ala-Gly-Phe-Leu-Arg) in the concentration 0.1 μM for 6 hours. To simulate oxidative stress, 60 μM H2O2 was added to the culture medium for 2 hours. Experimental series included (1) «control»; (2) «non-opiate leu-enkephalin analogue» (the peptide was added to the culture medium 44 hours after the final passage); (3) «oxidative stress» (H2O2 was added to the culture medium 48 hours after the final passage); (4) «non-opiate leu-enkephalin analogue + oxidative stress» (the peptide and H2O2 were added to the culture medium 44 and 48 hours respectively after the final passage). In order to evaluate the generation of superoxide anion by pulmonary fibroblasts, the method of lucigenin-dependent chemiluminescence was used. Computer morphometry of the nucleo-nucleolar apparatus of fibroblasts stained with silver nitrate by the AgNOR method was used to assess the cell state: the area of fibroblast nuclei, the total nucleoli area in the nucleus, and the number of nucleoli in the nucleus were measured. These parameters correlate with the activity of anabolic processes in the cells. Results. The effect of H2O2 on the primary culture of pulmonary fibroblasts caused an increase of superoxide anion generation by the fibroblasts, reduction of fibroblast nuclei size, decrease of nucleoli amount and size. Pre-incubation of pulmonary fibroblasts with a non-opioid leu-enkephalin analogue reduced the H2O2-induced generation of superoxide anion, corrected changes in the nucleo-nucleolar apparatus of fibroblasts caused by oxidative stress. In our previous studies, similar effect in the same model was shown for non-selective μ/δ-opioid receptor agonist peptide sedatin (dermorphin analogue). The mechanism of cytoprotective effect of non-opioid leu-enkephalin analogue may include the affinity of this peptide to nociceptin receptors (NOR receptors) that requires further studies. Conclusion. The results of the study indicate a direct cytoprotective effect of the peptide Phe-D-Ala-Gly-Phe-Leu-Arg (non-opioid leu-enkephalin analogue) in oxidative stress

Diabetes mellitus in the Russian Federation: dynamics of epidemiological indicators according to the Federal Register of Diabetes Mellitus for the period 2010–2022

BACKGROUND. The clinical and epidemiological characteristics of diabetes mellitus (DM) and the quality of its therapy are the key prognostic dominant that determines the organizational aspects of the diabetic service. The continuous dynamic   monitoring of DM has been carried out in the Russian Federation (RF) since 1996 through the activities of the Federal Register of Diabetes Mellitus (FDR).AIMS. The aim of our study was to analyze the epidemiological characteristics of DM in the RF (prevalence, morbidity, mortality), the prevalence diabetic of complications, the state of carbohydrate metabolism (level of HbA1c) and the dynamics of the structure of glucose-lowering therapy (GLT) according to the FDR.MATERIALS AND METHODS. The database of FRD (https://www.diaregistry.ru/), 85 regions of the RF. The data are presented as of 01.01.2023 and in dynamics for the period 2010–2022.RESULTS. The total number of DM patients in the RF as of 01.01.2023 was 4 962 762 (3.31% of the population), including: Type 1 (T1) — 5.58% (277.1 ths), T2 — 92.33% (4.58 million), other DM types —2.08% (103 ths). The dynamics of prevalence over the 13-year period (2010→2022) was 146.0→191.0/100 ths people with T1, and 2036.2→3158.8/100 ths people with T2; morbidity in T1 12.3→8.2/100 ths population, in T2 260.1→191.4/100 ths population; мortality: T1 2.1→2.4/100 ths population, T2 41.2→86.1/100 ths of the population. The main cause of death was cardiovascular: in T1 38.6% cases, in T2 — 50.9%. Life expectancy (average age of death of patients): T1 was 52.7 years, the dynamics in males 50.9 → 50.7 years, females 62.1→56.0 years; in T2 — 74.2 years, males 69.5→70.4 years, females 74.2→76.1 years. The dynamic of DM duration from onset to the death: in T1 15.4→19.9 years; in T2 11→11.4 10.2→11.8 years. The proportion of patients with laboratory-measured HbA1c <7% in the dynamics of 2010–2022: with DM1 24.4%→29%, with DM2 41.5%→42.2%, with HbA1c ≥9.0%: with DM1 29, 4% → 20.4%, with DM2 13.8 → 9.0%.The incidence of diabetic complications as of 01.01.2023 in T1 and T2 patients: neuropathy 41.3% and 23.7%, nephropathy (CKD) 22.8% and 19.1%, retinopathy 28.9% and 12.3%, respectively. The structure GLT in T2 patients as of 01.01.2023: monotherapy — 41.6%; combination of 2 GLM — 30.0%, 3 GLM — 5.8%, insulin therapy in 18.3%.CONCLUSIONS. The information-analytical system FDR is a key tool for systematizing the most important epidemiological and clinical characteristics of DM based on data from real clinical practice, which allows optimizing the algorithm of patient management and improving the quality of care for diabetes

Changes in aortic root dimensions after ascending aortic repair with concomitant aortic valve replacement

The issue of ascending aortic repair with concomitant aortic valve replacement in pa-tients with ascending aortic aneurysm (AscAA) and aortic valve stenosis is still debatable.Aim. To analyze the dimension changes of the preserved aortic root after simultaneous ascending aorta repair and aortic valve replacement.Material and methods. This retrospective study included 102 patients who, from December 2012 to May 2022, underwent simultaneous aortic valve replacement and ascending aorta repair with hemiarch replacement. Patients were divided into 2 following groups based on the aortic valve morphology: group 1 — patients with bicuspid aortic valve (BAV) and AscAA (n=75), group 2 — patients with tricuspid aortic valve (TAV) and AscAA (n=27). Depending on the presence of aortic root dilatation (maximum diameter (d) >40 mm), each of the groups was additionally stratified into 2 more subgroups as follows: patients without aortic root dilatation (d≤40 mm) and patients with its dilatation (d>40 mm). The dynamics of the aortic root diameter was assessed by computed tomography angiography.Results. The mean follow-up period for patients was 36,2±14,6 months. Survival rate in the BAV+AscAA and TAV+AscAA groups was 96% and 100%, respectively (p=0,380). Freedom from aortic root resurgery was 100% in both study groups. In patients with dilated and non-dilated aortic root of the BAV+AscAA group, an increase in aortic root dimension was noted at a rate of 0,65±0,51 mm/year and 0,32±0,27 mm/year, respectively. In patients of the TAV+AscAA group, a regression in dilated and non-dilated aortic root diameter was observed as follows: 0,93±0,48 mm/year and 0,56±0,43 mm/year, respectively.Conclusion. In patients with AscAA in combination with BAV stenosis after a singlestep surgical intervention, a weak negative dynamics of non-dilated and dilated aortic root is observed in the mid-term follow-up period. In patients with AscAA and TAV, there is involutive alterations of the aortic root dimension during 3-year follow-up