On the Equivalence Between Type I Liouville Dynamical Systems in the Plane and the Sphere

Producción CientíficaSeparable Hamiltonian systems either in sphero-conical coordinates on an S2 sphere or in elliptic coordinates on a R2 plane are described in a unified way. A back and forth route connecting these Liouville Type I separable systems is unveiled. It is shown how the gnomonic projection and its inverse map allow us to pass from a Liouville Type I separable system with a spherical configuration space to its Liouville Type I partners where the configuration space is a plane and back. Several selected spherical separable systems and their planar cousins are discussed in a classical context

Socioeconomic inequalities in physiological risk biomarkers and the role of lifestyles among Russians aged 35-69 years.

BACKGROUND: Socioeconomic inequalities in cardiovascular (CVD) health outcomes are well documented. While Russia has one of the highest levels of CVD mortality in the world, the literature on contemporary socio-economic inequalities in biomarker CVD risk factors is sparse. This paper aims to assess the extent and the direction of SEP inequalities in established physiological CVD risk biomarkers, and to explore the role of lifestyle factors in explaining SEP inequalities in physiological CVD risk biomarkers. METHODS: We used cross-sectional data from a general population-based survey of Russians aged 35-69 years living in two cities (n = 4540, Know Your Heart study 2015-18). Logistic models were used to assess the associations between raised physiological risk biomarkers levels (blood pressure levels, cholesterol levels, triglycerides, HbA1C, and C-reactive protein) and socioeconomic position (SEP) (education and household financial constraints) adjusting for age, obesity, smoking, alcohol and health-care seeking behavior. RESULTS: High education was negatively associated with a raised risk of blood pressure (systolic and diastolic) and C-reactive protein for both men and women. High education was positively associated with total cholesterol, with higher HDL levels among women, and with low triglycerides and HbA1c levels among men. For the remaining risk biomarkers, we found little statistical support for SEP inequalities. Adjustment for lifestyle factors, and particularly BMI and waist-hip ratio, led to a reduction in the observed SEP inequalities in raised biomarkers risk levels, especially among women. High financial constraints were weakly associated with high risk biomarkers levels, except for strong evidence for an association with C-reactive protein (men). CONCLUSIONS: Notable differences in risk biomarkers inequalities were observed according to the SEP measure employed. Clear educational inequalities in raised physiological risk biomarkers levels, particularly in blood pressure and C-reactive protein were seen in Russia and are partly explained by lifestyle factors, particularly obesity among women. These findings provide evidence-based information on the need for tackling health inequalities in the Russian population, which may help to further contribute to CVD mortality decline

Prevalence of symptoms, ever having received a diagnosis and treatment of depression and anxiety, and associations with health service use amongst the general population in two Russian cities

BACKGROUND: Little is known about the burden of common mental disorders in Russia despite high levels of suicide and alcohol-related mortality. Here we investigated levels of symptoms, self-reports of ever having received a diagnosis and treatment of anxiety and depression in two Russian cities. METHODS: The study population was men and women aged 35-69 years old participating in cross-sectional population-based studies in the cities of Arkhangelsk and Novosibirsk (2015-18). Participants completed an interview which included the PHQ-9 and GAD-7 scales, questions on whether participants had ever received a diagnosis of depression or anxiety, and health service use in the past year. Participants also reported current medication use and medications were coded in line with the WHO anatomical therapeutic classification (ATC). Depression was defined as PHQ-9 ≥ 10 and Anxiety as GAD-7 ≥ 10. RESULTS: Age-standardised prevalence of PHQ-9 ≥ 10 was 10.7% in women and 5.4% in men (GAD-7 ≥ 10 6.2% in women; 3.0% in men). Among those with PHQ-9 ≥ 10 17% reported ever having been diagnosed with depression (equivalent finding for anxiety 29%). Only 1.5% of those with PHQ-9 ≥ 10 reported using anti-depressants and 0.6% of those with GAD-7 ≥ 10 reported using anxiolytics. No men with PHQ-9 ≥ 10 and/or GAD-7 ≥ 10 reported use of anti-depressants or anxiolytics. Use of health services increased with increasing severity of both depression and anxiety. CONCLUSION: There was a large gap between symptoms and reporting of past diagnosis and treatment of common mental disorders in two Russian cities. Interventions aimed at improving mental health literacy and reducing stigma could be of benefit in closing this substantial treatment gap

Integrated plasmonic circuitry on a vertical-cavity surface-emitting semiconductor laser platform

Integrated plasmonic sources and detectors are imperative in the practical development of plasmonic circuitry for bio- and chemical sensing, nanoscale optical information processing, as well as transducers for high-density optical data storage. Here we show that vertical-cavity surface-emitting lasers (VCSELs) can be employed as an on-chip, electrically pumped source or detector of plasmonic signals, when operated in forward or reverse bias, respectively. To this end, we experimentally demonstrate surface plasmon polariton excitation, waveguiding, frequency conversion and detection on a VCSEL-based plasmonic platform. The coupling efficiency of the VCSEL emission to waveguided surface plasmon polariton modes has been optimized using asymmetric plasmonic nanostructures. The plasmonic VCSEL platform validated here is a viable solution for practical realizations of plasmonic functionalities for various applications, such as those requiring sub-wavelength field confinement, refractive index sensitivity or optical near-field transduction with electrically driven sources, thus enabling the realization of on-chip optical communication and lab-on-a-chip devices

Comparing prevalence of chronic kidney disease and its risk factors between population-based surveys in Russia and Norway.

BACKGROUND: Little data exists on the prevalence of chronic kidney disease (CKD) in the Russian population. We aimed to estimate the prevalence of CKD in a population-based study in Russia, compare with a similar study in Norway, and investigate whether differences in risk factors explained between-study differences in CKD. METHODS: We compared age- and sex-standardised prevalence of reduced eGFR (< 60 ml/min/1.73m2 CKD-EPI creatinine equation), albuminuria and or a composite indicator of CKD (one measure of either reduced eGFR or albuminuria) between participants aged 40-69 in the population-based Know Your Heart (KYH) study, Russia (2015-2018 N = 4607) and the seventh Tromsø Study (Tromsø7), Norway (2015-2016 N = 17,646). We assessed the contribution of established CKD risk factors (low education, diabetes, hypertension, antihypertensive use, smoking, obesity) to between-study differences using logistic regression. RESULTS: Prevalence of reduced eGFR or albuminuria was 6.5% (95% Confidence Interval (CI) 5.4, 7.7) in KYH and 4.6% (95% CI 4.0, 5.2) in Tromsø7 standardised for sex and age. Odds of both clinical outcomes were higher in KYH than Tromsø7 (reduced eGFR OR 2.06 95% CI 1.67, 2.54; albuminuria OR 1.54 95% CI 1.16, 2.03) adjusted for sex and age. Risk factor adjustment explained the observed between-study difference in albuminuria (OR 0.92 95% CI 0.68, 1.25) but only partially reduced eGFR (OR 1.42 95% CI 1.11, 1.82). The strongest explanatory factors for the between-study difference was higher use of antihypertensives (Russian sample) for reduced eGFR and mean diastolic blood pressure for albuminuria. CONCLUSIONS: We found evidence of a higher burden of CKD within the sample from the population in Arkhangelsk and Novosibirsk compared to Tromsø, partly explained by between-study population differences in established risk factors. In particular hypertension defined by medication use was an important factor associated with the higher CKD prevalence in the Russian sample

Alcohol and fatal life trajectories in Russia: understanding narrative accounts of premature male death in the family

Background: In the post-Soviet period, Russian working-age men have suffered unusually high mortality rates. Earlier quantitative work found that part of this is attributable to hazardous and harmful patterns of alcohol consumption, which increased in the period of transition at a time of massive social and economic disruption and uncertainty. However, there has been very little work done to document and understand in detail the downward life trajectories of individual men who died prematurely from alcohol-related conditions. Building on an earlier case-control study, this unique qualitative study investigates the perceived interplay between men's drinking careers, their employment and family history, health and eventual death.Methods: In-depth interviews were conducted with close relatives (most often the widow) of 19 men who died between 2003 and 2005 aged 25-54 years whose close relatives reported that alcohol contributed to their death. The study was conducted in a typical medium-sized Russian city. The relative's accounts were analysed using thematic content analysis.Results: The accounts describe how hazardous drinking both contributed to serious employment, family and health problems, and was simultaneously used as a coping mechanism to deal with life crises and a decline in social status. The interviews highlighted the importance of the workplace and employment status for shaping men's drinking patterns. Common themes emerged around a culture of drinking in the workplace, peer pressure from colleagues to drink, use of alcohol as remuneration, consuming non-beverage alcohols,Russian-specific drinking patterns, attitudes to treatment, and passive attitudes towards health and drinking.Conclusions: The study provides a unique insight into the personal decline that lies behind the extremely high working-age mortality due to heavy drinking in Russia, and highlights how health status and hazardous drinking are often closely intertwined with economic and social functioning. Descriptions of the development of drinking careers, hazardous drinking patterns and treatment experiences can be used to plan effective interventions relevant in the Russian context

Availability and Affordability of Medicines for the Treatment of Cardiovascular Diseases in Pharmacies in Six Regions of the Russian Federation

Aim. To evaluate the availability and affordability of medicines used to treat of cardiovascular diseases (CVD) in several regions of the Russian Federation with different climatic, geographic, economic and demographic characteristics. Material and methods. The study was conducted in 6 regional capitals, chosen to differ in geographically, economically, and demographically. In each city, 5 pharmacies providing free medicines to certain categories of citizens (beneficiaries) and 5 private pharmacies serving anyone were selected at random. Medicine availability was assessed in all pharmacies, along with price only in the private pharmacies. Data were obtained for both original drug and appropriate generics. A list of 25 of the most frequently prescribed medicines for cardiovascular diseases was compiled. Results. Some general findings emerged. With the existence of a generic drug, the original drug was not available in the pharmacy supplying beneficiaries. Diuretics, as well as some ACE inhibitors, are not available in a number of pharmacies for beneficiaries. Enalapril in most licensed pharmacies is represented by generics, lisinopril in a number of cities is represented by both the original drug and generics. The presence of sartans was much lower than ACE inhibitors. Bisoprolol was most common beta-blocker. Calcium antagonists: if amlodipine was present in all licensed pharmacies, at list as generic, then nifedipine was not available in many licensed pharmacies. Among antiplatelet agents, aspirin was available in most pharmacies, and clopidogrel was mostly represented by generics. As for statins, only simvastatin could be found in almost all pharmacies. When analyzing the cost of drugs in licensed pharmacies, it was found that drugs containing furosemide are the cheapest among generics – about 17 rubles. The most expensive treatment with generics of rosuvastatin – about 4,374 rubles a month. The most expensive original medicine was also rosuvastatin – about 4,500 rubles for 30 tablets, the cheapest – the original drug of furosemide – about 35 rubles. On average, the cost of CVD treatment with major classes of drugs, including ACE inhibitor, beta-blocker, antiplatelet drug and statin, is 1,921.9 rubles per month. Conclusion. The basic cardiovascular medicines were characterized by a relatively high availability in 6 regions of the Russian Federation included in the analysis both by the criterion of the availability of drugs and by the criterion of the minimum price.</jats:p

Dimensionality of Carbon Nanomaterials Determines the Binding and Dynamics of Amyloidogenic Peptides: Multiscale Theoretical Simulations

Experimental studies have demonstrated that nanoparticles can affect the rate of protein self-assembly, possibly interfering with the development of protein misfolding diseases such as Alzheimer's, Parkinson's and prion disease caused by aggregation and fibril formation of amyloid-prone proteins. We employ classical molecular dynamics simulations and large-scale density functional theory calculations to investigate the effects of nanomaterials on the structure, dynamics and binding of an amyloidogenic peptide apoC-II(60-70). We show that the binding affinity of this peptide to carbonaceous nanomaterials such as C60, nanotubes and graphene decreases with increasing nanoparticle curvature. Strong binding is facilitated by the large contact area available for π-stacking between the aromatic residues of the peptide and the extended surfaces of graphene and the nanotube. The highly curved fullerene surface exhibits reduced efficiency for π-stacking but promotes increased peptide dynamics. We postulate that the increase in conformational dynamics of the amyloid peptide can be unfavorable for the formation of fibril competent structures. In contrast, extended fibril forming peptide conformations are promoted by the nanotube and graphene surfaces which can provide a template for fibril-growth