3,198 research outputs found
Structure and diffusion processes in laminated composites of a Cu-Ti system
Characteristics of diffusion transformations in a multi-layer composite of a Cu-Ti system, which was produced by high-temperature diffusion welding followed by rolling at room temperature, are reportedye
Predictive value of cardiovascular risk factors in the formation of cardiovascular and all-cause mortality: results of a 27-year cohort prospective study
Aim. To study the prognostic significance of cardiovascular risk factors (RFs) in the formation of all-cause and cardiovascular mortality based on the results of a 27-year prospective cohort study of Tomsk population of both sexes aged 20-59 years.Material and methods. The object of study was random house-to-house sample of Tomsk population. In total, 1546 people (630 men and 916 women) aged 20-59 were examined. In 1988-1991, the prevalence of following cardiovascular RFs was studied: hypertension (HTN), overweight, smoking, alcohol consumption, hypercholesterolemia (HCE), low high-density lipoprotein cholesterol levels (hypo-HDL-emia), hypertriglyceridemia (HTG). All examination methods used were strictly standardized. To determine the RF, the criteria generally accepted in epidemiological studies were used. Over 27 years of follow-up, 330 deaths were recorded, including 142 due to cardiovascular disease.Results. In the multivariate Cox proportional hazard model, the following variables were studied: HTN, overweight, smoking, alcohol consumption, HCE, hypo-HDL-emia, HTG, coronary artery disease (CAD) (according to epidemiological criteria), and age. The strongest predictor of of all-cause death was frequent alcohol use (relative risk (RR) 2,75). Smoking increased the risk of death by 2,72 times. Among former smokers, the risk of all-cause death was 1,9 times higher compared to non-smokers. HTN increases the death risk by 1,61 times. Each year of life lived increases the death risk by 1,06 times. The most significant risk factor for death from CVD was frequent alcohol consumption (RR 3,01). Smoking increases the cardiovascular death risk by 2,28 times. Among former smokers, the RR of cardiovascular death was 1,91. HTN increases the risk of cardiovascular mortality by 1,84 times compared with people with normal blood pressure. Each year of life lived increases the risk of cardiovascular death by 1,1 times. In multivariate analysis, overweight, HCE, hypo-HDL-emia, HTG did not have a significant independent effect on the all-cause and cardiovascular death risk.Conclusion. In a 27-year cohort prospective study, independent predictors of all-cause and cardiovascular mortality, along with hypertension and age, were lifestyle risk factors, such as smoking and frequent alcohol consumption
Future of superheavy element research: Which nuclei could be synthesized within the next few years?
Low values of the fusion cross sections and very short half-lives of nuclei
with Z120 put obstacles in synthesis of new elements. Different nuclear
reactions (fusion of stable and radioactive nuclei, multi-nucleon transfers and
neutron capture), which could be used for the production of new isotopes of
superheavy (SH) elements, are discussed in the paper. The gap of unknown SH
nuclei, located between the isotopes which were produced earlier in the cold
and hot fusion reactions, can be filled in fusion reactions of Ca with
available lighter isotopes of Pu, Am, and Cm. Cross sections for the production
of these nuclei are predicted to be rather large, and the corresponding
experiments can be easily performed at existing facilities. For the first time,
a narrow pathway is found to the middle of the island of stability owing to
possible -decay of SH isotopes which can be formed in ordinary fusion
reactions of stable nuclei. Multi-nucleon transfer processes at near barrier
collisions of heavy (and very heavy, U-like) ions are shown to be quite
realistic reaction mechanism allowing us to produce new neutron enriched heavy
nuclei located in the unexplored upper part of the nuclear map. Neutron capture
reactions can be also used for the production of the long-living neutron rich
SH nuclei. Strong neutron fluxes might be provided by pulsed nuclear reactors
and by nuclear explosions in laboratory conditions and by supernova explosions
in nature. All these possibilities are discussed in the paper.Comment: An Invited Plenary Talk given by Valeriy I. Zagrebaev at the 11th
International Conference on Nucleus-Nucleus Collisions (NN2012), San Antonio,
Texas, USA, May 27-June 1, 2012. To appear in the NN2012 Proceedings in
Journal of Physics: Conference Series (JPCS
Low temperature breakdown of coherent tunneling in amorphous solids induced by the nuclear quadrupole interaction
We consider the effect of the internal nuclear quadrupole interaction on
quantum tunneling in complex multi-atomic two-level systems. Two distinct
regimes of strong and weak interactions are found. The regimes depend on the
relationship between a characteristic energy of the nuclear quadrupole
interaction and a bare tunneling coupling strength
. When , the internal interaction is
negligible and tunneling remains coherent determined by . When
, coherent tunneling breaks down and an effective
tunneling amplitude decreases by an exponentially small overlap factor
between internal ground states of left and right wells of a
tunneling system. This affects thermal and kinetic properties of tunneling
systems at low temperatures . The theory is applied for
interpreting the anomalous behavior of the resonant dielectric susceptibility
in amorphous solids at low temperatures mK where the nuclear
quadrupole interaction breaks down coherent tunneling. We suggest the
experiments with external magnetic fields to test our predictions and to
clarify the internal structure of tunneling systems in amorphous solids.Comment: To appear in the Physical Review
Exceptional Collections and del Pezzo Gauge Theories
Stacks of D3-branes placed at the tip of a cone over a del Pezzo surface
provide a way of geometrically engineering a small but rich class of
gauge/gravity dualities. We develop tools for understanding the resulting
quiver gauge theories using exceptional collections. We prove two important
results for a general quiver gauge theory: 1) we show the ordering of the nodes
can be determined up to cyclic permutation and 2) we derive a simple formula
for the ranks of the gauge groups (at the conformal point) in terms of the
numbers of bifundamentals. We also provide a detailed analysis of four node
quivers, examining when precisely mutations of the exceptional collection are
related to Seiberg duality.Comment: 26 pages, 1 figure; v2 footnote 2 amended; v3 ref adde
Measurement of decay rate and parameters at KEDR
Using the inclusive photon spectrum based on a data sample collected at the
peak with the KEDR detector at the VEPP-4M collider, we
measured the rate of the radiative decay as well
as mass and width. Taking into account an asymmetric photon
lineshape we obtained keV, MeV/, MeV.Comment: 6 pages, 3 figure
Ways to increase adherence to antihypertensive therapy
With a high prevalence in the Russian population and insufficient effectiveness of treatment, hypertension remains a poorly controlled cardiovascular risk factor, including due to the low compliance of patients. Noncompliance is due to a large number of factors, some of which were studied in post-hoc analysis of the Russian observational STIL’ and TRICOLOR studies. It demonstrated that fixed-dose combinations of antihypertensive drugs can make a significant contribution to solving such a complex problem as low compliance
Spousal body weight concordance and the impact of spouse overweight on death risk: data form a 27-year cohort prospective study
Aim. To study the interdependence of spousal body mass and influence of spouse overweight on the death risk according to the 27-year cohort prospective study.Material and methods. We examined a random household sample (n=1546; married couples, 427). Overweight frequency among spouses was studied on the first stage of the study (1988-1991). In 2002-2005 (stage II), the examination was repeated and overweight dynamics were studied. In 2015 (stage III), we analyze mortality rates and significance of overweight and spousal overweight for the mortality risk formation. Overweight was detected in people with body mass index ≥25 kg/m2. Two hundred deaths were recorded during 27-year follow-up. Vital status was established for 97% of observed persons.Results. Overweight was detected in 61,1% of men who lived with overweight wife and in 45% of men whose wife had normal body mass (p<0,01). Overweight was diagnosed more often in women whose husband also had overweight comparing with women who lived with normal weight husband (76,2% vs 61,7%; p<0,001). The risk of overweight formation among individuals whose spouse’s body mass increased from norm to overweight was in 3,04 times higher than in persons whose spouse had a stable normal body mass and in 2,2 times higher than in participants whose spouse had overweight on study stages I and II. Relative risk of mortality in men who lived with overweight wife was 2,07.Conclusion. 1) We found the body mass concordance in spouses. 2) The average body mass index in men and women who lived with overweight spouse is higher than in men and women whose spouse had a normal body mass. 3) Interdependence of spousal body mass was revealed in dynamics. 4) Spousal overweight is an independent predictor of premature mortality in men
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