347 research outputs found
Invariants of elliptic and hyperbolic CR-structures of codimension 2
We reduce CR-structures on smooth elliptic and hyperbolic manifolds of
CR-codimension 2 to parallelisms thus solving the problem of global equivalence
for such manifolds. The parallelism that we construct is defined on a sequence
of two principal bundles over the manifold, takes values in the Lie algebra of
infinitesimal automorphisms of the quadric corresponding to the Levi form of
the manifold, and behaves ``almost'' like a Cartan connection. The construction
is explicit and allows us to study the properties of the parallelism as well as
those of its curvature form. It also leads to a natural class of ``semi-flat''
manifolds for which the two bundles reduce to a single one and the parallelism
turns into a true Cartan connection. In addition, for real-analytic manifolds
we describe certain local normal forms that do not require passing to bundles,
but in many ways agree with the structure of the parallelism.Comment: 42 pages, see also
http://wwwmaths.anu.edu.au/research.reports/97mrr.htm
A New World Average Value for the Neutron Lifetime
The analysis of the data on measurements of the neutron lifetime is
presented. A new most accurate result of the measurement of neutron lifetime
[Phys. Lett. B 605 (2005) 72] 878.5 +/- 0.8 s differs from the world average
value [Phys. Lett. B 667 (2008) 1] 885.7 +/- 0.8 s by 6.5 standard deviations.
In this connection the analysis and Monte Carlo simulation of experiments
[Phys. Lett. B 483 (2000) 15] and [Phys. Rev. Lett. 63 (1989) 593] is carried
out. Systematic errors of about -6 s are found in each of the experiments. The
summary table for the neutron lifetime measurements after corrections and
additions is given. A new world average value for the neutron lifetime 879.9
+/- 0.9 s is presented.Comment: 27 pages, 13 figures; Fig.13 update
Economic aspects of the cardiology program expansion of additional drugs provision by effective lipidlowering drugs for hypercholesterolemia control
The federal program of preferential drug provision in cardiology shows its effectiveness. However, hypercholesterolemia (HCH) remains a significant problem in patients in whom high-dose statin therapy does not provide the target level of low-density lipoprotein cholesterol (LDL cholesterol). The solution to the problem lies in the plane of prescribing lipid-lowering drugs of a different mechanism of action, for example, inhibitors of the PCSK9 enzyme. To recommend the inclusion of such kind drugs in the program, it is necessary not only to have evidence of their life-saving effect, but also the economic feasibility of their use. Aim: to evaluate the economic efficacy of alirocumab (INN) including in the federal program for patients who have suffered an acute coronary event, are receiving statins and have an LDL CH level of 5.0 mmol/l and higher.Materials and methods. Modeling was applied in a target group of 3029 patients of working age who had undergone ACS during the previous 12 months with severe, including familial, HCH, with LDL cholesterol 5.0 mmol/l and higher, receiving statins taking into account previously determined outcomes when using alirocumab + statins for 5 years. Direct medical and non-medical costs, as well as indirect costs, are identified. The cost-effectiveness analysis was applied from the point of view of the effectiveness of treatment (effects on mortality, temporary disability, disability) and direct health care costs (additional drug provision and outpatient follow-up, specialized, including high-tech, medical care in a 24‑hour hospital). Two healthcare technologies were compared: statin therapy and use of alirocumab + statins. The calculations used according to domestic methods used the cost of medical treatment, temporary disability, hospitalizations, loss of GDP and other parameters.Results. Modeling has shown a decrease in mortality, morbidity and disability when using alirocumab in even the first year of use. The economic effect of alirocumab from a decrease in temporary disability in the 1st year is 304.5 mln rub., in the 2nd — 301.5 mln rub., in the 3rd — 321.1 mln rub., in the 4th — 333.1 mln rub. The estimated amount of prevented GDP losses from mortality in the target group for 4 years in the case of alirocumab use amounted to 1,260.2 mln rub. The annual amount of avoidable GDP losses from mortality in the target group in the case of alirocumab is 27–30 %. The annual average savings per patient in the case of alirocumab use are from 7 to 17 %. The greatest impact on reducing losses from disability and mortality of the target group is noted in the group of people aged 40–59 years. Only for this group, if alirocumab is used, it is possible to reduce losses from disability and mortality by 159.2 million rubles per year (83 % of the total economic effect). Starting from the 4th year of alirocumab use, it is possible to obtain a positive economic effect in terms of hospitalization costs.Conclusion. When alirocumab is included in the program of additional drug provision in cardiology, the share of costs for the purchase of alirocumab for the target group may be only 0.01 %. At the same time, the economic effect of inclusion in the first year alone will amount to at least 393.4 million rubles of budget funds. The total amount of avoidable losses due to the alirocumab usage may amount to 1,638 million rubles over 4 years
Influence of desinchronizing effects of transmeridian flights on the circadian rhythm of sportsmen arterial pressure
Objective: to examine the characteristics and duration of phase-amplitude changes in circadian systolic rhythms (ADS) and diastolic blood pressure (ADD) in athletes in contrasting time regions on a east-west flight model in 7 time zones. Materials and methods: the registration of blood pressure was carried out at 07, 11, 15, 19, 23 hours of local time in «home» conditions and 28 days after the flights to the regions of the Moscow time zone. The methodology was based on a graphic representation of the material. Biorhythm graphs were imposed on the «home» periodogram in new temporal conditions, which made it possible to evaluate the phase-amplitude changes in the chronograms and find out when the patterns would repeat, i.e. adaptation of systemic blood pressure to geo-social changes in the environment. Results: it was shown that until the last 28th day of the study, the inverse deformation of the daily schedules of the BPA, BPA, a significant decrease in the BPA and pulse pressure (hypotensive effect), an increase in the BPA, an increase in the amplitude of fluctuations of the indicators remained. Conclusions: changes in the circadian rhythm of blood pressure in athletes in the regions with a 7-hour difference went beyond the month of research, indicating an incomplete adaptation of the hemodynamic system, which functioning was provided by a more costly, unprofitable for the body physiological mechanism that impairs the efficiency of the heart and at rest
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