Mathematical modeling of the refractive effect of SMILE surgery in high degree myopia correction

The aim of the study. To develop a mathematical model of changes in corneal refraction during femtosecond laser-assisted lenticule extraction through a small surgical incision and, on this basis, to propose a technology for modified calculation of surgical parameters and to prove its effectiveness. Material and methods. The study included 191 patients with high myopia. They were divided into two groups: group  1 consisted of 55  patients who  were  had  SMILE (SMall Incision Lenticule Extraction) surgery with standard calculations; group  2 included 136 patients who had SMILE surgery with a modified calculation of surgical parameters based on the developed mathematical model of the refractive effect of the surgery. Results. When assessing the refractive effect of patients who were operated using standard technology, it was found that it was possible to achieve a refraction different from emmetropia for ± 0.5 D only in 51 % of cases; in the remaining patients, the planned residual refractive effect was obtained and averaged –1.96 ± 0.29 D. In patients operated using the modified technology, a statistically significantly better refractive result was achieved already on the first day. A refractive error of more than ± 1.0 D was obtained in only 1 % of cases; a deviation from the calculated refraction of ± 0.5 D was achieved in 82 % of cases, with the average values by 1 year –0.24 ± 0.57 D. Conclusions. The developed technology of a modified calculation of the parameters of the SMILE surgery for high myopia correction makes it possible to obtain an optimal refractive effect in compliance with safety rules when the structural and functional parameters of the eye are initially unfavorable for refractive surgery

Financial Risks of Russian Oil Companies in Conditions of Volatility of Global Oil Prices

The development of scientific approaches to assessing and diagnosing the financial risks of oil industry in the Russian Federation becomes a high priority task in conditions of high level of volatility in oil prices in the world energy market and preservation of sanctions regime. The article shows the main threats to financial stability of oil companies in Russia. Using cluster analysis, a system of indicators is proposed that determines the level of financial risk of oil companies in Russia. Based on the method of expert assessments and fuzzy sets, the classification of financial risk levels of oil industry is proposed. The integrated financial risk level of oil industry was calculated and scenarios of its development for 2018–2020 were forecast by means of regression modeling. The system of measures to improve the stability of oil companies and prevent functional financial risks is argued. The practical implementation of research results will be the basis for timely diagnosis of financial risks and qualitative development of preventive measures to neutralize them in the oil industry of Russia. Keywords: Oil Industry, Oil Companies, Financial Risks, Oil Prices, Financial Stability of Oil Industry JEL Classifications: Q43; Q41; G32; L52 DOI: https://doi.org/10.32479/ijeep.735

Pathogenicity of the SARS-CoV-2 Virus Variants of Concern for the Syrian Golden Hamster

The aim of the work was to study the pathogenicity of newly emerging variants of SARS-CoV-2 on the model of the Syrian golden hamster.Materials and methods. We used the strains of SARS-CoV-2 virus related to the VOC circulating in the territory of the Russian Federation. The experiments were carried out on outbreed Syrian hamsters obtained from the nursery of the SSC VB “Vector”. The infectious titer of coronavirus in tissue samples collected from infected laboratory animals was determined on a Vero E6 cell culture. The Ct in RT-PCR was considered an additional parameter for monitoring the viral load in the samples. The severity of lung tissue damage in Syrian hamsters with COVID-19 was assessed by histological preparations.Results and discussion. 50 % infecting doses in case of the intranasal infection have been determined, histological analysis of lung tissues performed. The pathogenicity of various variants of the SARS-CoV-2 virus for the Syrian hamster has been evaluated, differences in infecting doses and pathological changes in the lungs have been revealed. SARS-CoV-2 viruses belonging to Beta genetic variant have the highest virulence, while Alpha variant has the lowest one when comparing the studied strains by the ID50 value. The Delta and Omicron variants have a matched ability to cause specific damage to the tissues of the respiratory tract, while being inferior only to the Beta variant. It has been demonstrated that Syrian hamsters are an adequate model for assessing the pathogenicity of the SARS-CoV-2 virus variants of concern. Variants of SARS-CoV-2 virus during intranasal infection has shown different degree of pathogenicity in the Syrian hamster model

Local polarization reversal in relaxor SBN single crystals by electron and ion beam irradiation

The equipment of the Ural Center for Shared Use “Modern Nanotechnology” UrFU was used. The research was made possible by the Russian Science Foundation (grant № 19-72-00008)

Cause of Death and Predictors of All-Cause Mortality in Anticoagulated Patients With Nonvalvular Atrial Fibrillation : Data From ROCKET AF

M. Kaste on työryhmän ROCKET AF Steering Comm jäsen.Background-Atrial fibrillation is associated with higher mortality. Identification of causes of death and contemporary risk factors for all-cause mortality may guide interventions. Methods and Results-In the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF) study, patients with nonvalvular atrial fibrillation were randomized to rivaroxaban or dose-adjusted warfarin. Cox proportional hazards regression with backward elimination identified factors at randomization that were independently associated with all-cause mortality in the 14 171 participants in the intention-to-treat population. The median age was 73 years, and the mean CHADS(2) score was 3.5. Over 1.9 years of median follow-up, 1214 (8.6%) patients died. Kaplan-Meier mortality rates were 4.2% at 1 year and 8.9% at 2 years. The majority of classified deaths (1081) were cardiovascular (72%), whereas only 6% were nonhemorrhagic stroke or systemic embolism. No significant difference in all-cause mortality was observed between the rivaroxaban and warfarin arms (P=0.15). Heart failure (hazard ratio 1.51, 95% CI 1.33-1.70, P= 75 years (hazard ratio 1.69, 95% CI 1.51-1.90, P Conclusions-In a large population of patients anticoagulated for nonvalvular atrial fibrillation, approximate to 7 in 10 deaths were cardiovascular, whereasPeer reviewe

Baseline characteristics of patients in the reduction of events with darbepoetin alfa in heart failure trial (RED-HF)

<p>Aims: This report describes the baseline characteristics of patients in the Reduction of Events with Darbepoetin alfa in Heart Failure trial (RED-HF) which is testing the hypothesis that anaemia correction with darbepoetin alfa will reduce the composite endpoint of death from any cause or hospital admission for worsening heart failure, and improve other outcomes.</p> <p>Methods and results: Key demographic, clinical, and laboratory findings, along with baseline treatment, are reported and compared with those of patients in other recent clinical trials in heart failure. Compared with other recent trials, RED-HF enrolled more elderly [mean age 70 (SD 11.4) years], female (41%), and black (9%) patients. RED-HF patients more often had diabetes (46%) and renal impairment (72% had an estimated glomerular filtration rate <60 mL/min/1.73 m2). Patients in RED-HF had heart failure of longer duration [5.3 (5.4) years], worse NYHA class (35% II, 63% III, and 2% IV), and more signs of congestion. Mean EF was 30% (6.8%). RED-HF patients were well treated at randomization, and pharmacological therapy at baseline was broadly similar to that of other recent trials, taking account of study-specific inclusion/exclusion criteria. Median (interquartile range) haemoglobin at baseline was 112 (106–117) g/L.</p> <p>Conclusion: The anaemic patients enrolled in RED-HF were older, moderately to markedly symptomatic, and had extensive co-morbidity.</p&gt