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Search Results: 1 - 10 of 464797 matches for " Yuri A. Karpov "
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Identification of Patients at High Cardiovascular Risk
Igor V. Sergienko, PhD, ScD,Saule J. Urazalina, PhD,Valery V. Kukharchuk, PhD, ScD,Yuri A. Karpov, PhD, ScD
International Journal of BioMedicine , 2012,
Abstract: Objective: To identify individuals at high cardiovascular risk (CVR) to check for an additional estimate of CVR with the use of the ESH/ESC Guidelines (2003, 2007) in patients earlier classified as being at low and moderate risk on SCORE . Material and methods: The study included 600 people (155 men and 445 women) with low and moderate cardiovascular risk on the SCORE scale. All patients were examined with duplex scanning of the carotid arteries (DSCA) to the determined of the thickness of the intima – media (IMT), the presence of atherosclerotic plaques (ASP); it has also been performed sphygmographic computer (SC) with automatic estimation of brachial-ankle pulse wave velocity (baPWV), biochemical analysis of blood lipid spectrum. Results: The frequency of ASP was 59.5% (357 out of 600), and a thickening of thecomplex "intima-media" (IMT)> 0.9 mm was detected in only 5% of the cases (28 persons out of 600), that indicated a slight contribution to the magnitude of the risk of such parameters as the IMT. The total number of patients with signs of preclinicallesions of the arterial wall (the presence of ASP and/or increased baPWV) was 337 (56% of 600). Our results showed that the presence of subclinical atherosclerosis is in itself a risk factor. Conclusion: The usage of instrumental methods of research (DSCA, SC) allowed to detect 32% of individuals with high CVR from 600 previously classified as low and moderate risk on SCORE scale. In our opinion, the proposed algorithm is convenient and easy to use for transfer of the patients into high-risk group.
Statines in prevention and treatment of atherosclerosis connected diseases: efficiency and safety
Y.A. Karpov
Rational Pharmacotherapy in Cardiology , 2005,
Abstract: Results of large-scale studies carried out during last 10 years and devoted to the assessment of statines efficiency in prevention of ischemic heart disease (IHD), are analyzed. Decrease in risks of myocardial infarction, instable angina pectoris and mortality by 25-40%, ischemic stroke — by 25-30% (CARE, LIPID, WOSCOPS, AFCAPS/TexCAPS, HPS, ASCOT-LLA, CARDS) is demonstrated. Recommendations for statines prescription for primary and secondary prevention of cardiovascular diseases, including IHD and ischemic stroke, are significantly expanded. New goals in holesterol of low density lipoproteid (HLDL) reduction are discussed, aswell as problems of statin treatment safety. The choice of the drug must be based on clinical research data, considering efficiency and safety at long-term use, as well as possibilities of achieving new goal level of HLDL.
ACE inhibitors in patients with ischemic heart disease without heart failure: class effects and efficacy of its representatives
Y.A. Karpov
Rational Pharmacotherapy in Cardiology , 2005,
Abstract: Results of large-scale studies (QUIET, HOPE, EUROPA, PEACE, CAMELOT), devoted to assessment of the role of ACE inhibitors in treatment of patients with stable form of ischemic heart disease without heart failure are analyzed. Different efficacy of the representatives of this class toward risks of coronary events development and cerebral-vascular complications is shown, as well as the overall mortality risk due to cardiovascular reasons. Favorable therapeutic effects of inhibiting RAS activity in patients without left ventricle dysfunction are demonstrated in studies EUROPA with perindopril 8 mg, and HOPE with ramipril 10 mg. That became the ground of inclusion of these drugs into recommendations for treatment of all patients with ischemic heart disease after myocardial infarction, in addition to antiplatelet, lipid reducing remedies and beta-blockers.
Report on open multicentral research program “PRIORITY” in clinical practice (Pektrol — quality of life in patients with stable angina pectoris treated with isosorbide-5-mononitrate in long-acting presentation)
Yu.A. Karpov
Rational Pharmacotherapy in Cardiology , 2006,
Abstract: Aim. In multicentral program PRIORITY to estimate the efficacy of antianginal therapy after switching patients with stable angina from therapy with short-acting nitrates or isosorbide dinitrate in long-term acting formulation to therapy with isosorbide-5-mononitrate (Pectrol, KRKA, Slovenia) in once daily administrated presentation.Materials and methods. PRIORITY program was held in out-patient clinics of 14 cities.286 patients with stable angina, who took short-acting nitrates or isosorbide dinitrate in long-term acting formulation, were included in research. Patients were switched without any break to the therapy with isosorbide-5-mononitrate (ISMN) in doze of 40 mg once a day, concomitant therapy was not changed. Initially and after 3 months of treatment with ISMN angina functional class, current therapy with nitrates and concomitant therapy were defined. Quality of life was also determined by questionnaire.Results. 275 patients finished program and 261 of them were completely corresponded to the study protocol. The treatment with ISMN reduced the frequency and duration of angina attacks (p<0,001), the frequency of sublingual nitroglycerine intake, resulted in the reduction of functional class of angina (p<0, 0001), the increase in walk distance without chest pain or dyspnoea (p<0, 0001). According to questioning 3 months treatment with ISMN resulted in physical exercise tolerance increase (p<0, 0001), reduction in number of side-effects of nitrates therapy (p<0, 0001) and frequency of angina attacks (p<0, 0001). Intensity of psychological discomfort was reduced (p<0,0001) and satisfaction with therapy was increased (p<0, 0001).Conclusion. Switching from short-acting nitrates or isosorbide dinitrate in long-term acting formulation to the therapy with ISMN showed corrective influence on life quality in patients with stable angina: frequency and duration of angina attacks significantly reduced, physical exercise tolerance increased, psycho-emotional condition and patient compliance improved.
Hot spot runaway in thin film photovoltaics and related structures
V. G. Karpov,A. Vasko,A. Vijh
Physics , 2013, DOI: 10.1063/1.4818975
Abstract: We show that thin film diode structures, such as photovoltaics and light emitting arrays, can undergo zero threshold localized thermal runaway leading to thermal and electrical nonuniformities spontaneously emerging in originally uniform systems. The linear stability analysis is developed for a system of thermally and electrically coupled two discrete diodes, and for a distributed system. These results are verified with numerical modeling that is not limited to small fluctuations. The discovered instability negatively affects the device performance and reliability. It follows that these problems can be mitigated by properly designing the device geometry and thermal insulation.
A circulation of false bank notes in the territory of the Penza region at the end of XVIII–beginning of XIX centuries
Kolchugina S. V.,Karpovа L. A.
Sociosfera , 2012,
Abstract: This article is devoted to a problem of circulation of false bank notes in the Russian Empire at the end the XVIII–beginning of the XIX centuries. Emergence in Russia at the end of the 1760th of paper money considerably simplified process of their fake that caused, together with known historical circumstances (for example, with events of Patriotic war of 1812), counterfeiting blossoming. The specified problem is considered on materials of the Penza edge which, being a part of the huge state, couldn't avoid in the history of those processes occurring in all Russia.
The Parasitic Dinoflagellates Blastodinium spp. Inhabiting the Gut of Marine, Planktonic Copepods: Morphology, Ecology, and Unrecognized Species Diversity
Alf Skovgaard,Sergey A. Karpov,Laure Guillou
Frontiers in Microbiology , 2012, DOI: 10.3389/fmicb.2012.00305
Abstract: Blastodinium is a genus of dinoflagellates that live as parasites in the gut of marine, planktonic copepods in the World’s oceans and coastal waters. The taxonomy, phylogeny, and physiology of the genus have only been explored to a limited degree and, based on recent investigations, we hypothesize that the morphological and genetic diversity within this genus may be considerably larger than presently recognized. To address these issues, we obtained 18S rDNA and ITS gene sequences for Blastodinium specimens of different geographical origins, including representatives of the type species. This genetic information was in some cases complemented with new morphological, ultrastructural, physiological, and ecological data. Because most current knowledge about Blastodinium and its effects on copepod hosts stem from publications more than half a century old, we here summarize and discuss the existing knowledge in relation to the new data generated. Most Blastodinium species possess functional chloroplasts, but the parasitic stage, the trophocyte, has etioplasts and probably a limited photosynthetic activity. Sporocytes and swarmer cells have well-developed plastids and plausibly acquire part of their organic carbon needs through photosynthesis. A few species are nearly colorless with no functional chloroplasts. The photosynthetic species are almost exclusively found in warm, oligotrophic waters, indicating a life strategy that may benefit from copepods as microhabitats for acquiring nutrients in a nutrient-limited environment. As reported in the literature, monophyly of the genus is moderately supported, but the three main groups proposed by Chatton in 1920 are consistent with molecular data. However, we demonstrate an important genetic diversity within the genus and provide evidences for new groups and the presence of cryptic species. Finally, we discuss the current knowledge on the occurrence of Blastodinium spp. and their potential impact on natural copepod populations.
Extending Hudson's theorem to mixed quantum states
A. Mandilara,E. Karpov,N. J. Cerf
Physics , 2008, DOI: 10.1103/PhysRevA.79.062302
Abstract: According to Hudson's theorem, any pure quantum state with a positive Wigner function is necessarily a Gaussian state. Here, we make a step towards the extension of this theorem to mixed quantum states by finding upper and lower bounds on the degree of non-Gaussianity of states with positive Wigner functions. The bounds are expressed in the form of parametric functions relating the degree of non-Gaussianity of a state, its purity, and the purity of the Gaussian state characterized by the same covariance matrix. Although our bounds are not tight, they permit us to visualize the set of states with positive Wigner functions.
Purity and Gaussianity bounded uncertainty relation
A. Mandilara,E. Karpov,N. J. Cerf
Physics , 2009,
Abstract: Bounded uncertainty relations provide the minimum value of the uncertainty assuming some additional information on the state. We derive analytically an uncertainty relation bounded by a pair of constraints, those of purity and Gaussianity. In a limiting case this uncertainty relation reproduces the purity-bounded derived by V I Man'ko and V V Dodonov and the Gaussianity-bounded one [Phys. Rev. A 86, 030102R (2012)].
Monotonic and cyclic components of radio pulsars spin-down
A. Biryukov,G. Beskin,S. Karpov
Physics , 2011, DOI: 10.1111/j.1365-2966.2011.20005.x
Abstract: In this article we revise the problem of anomalous values of pulsars' braking indices n_{obs} and frequency second derivatives F2 arising in observations. The intrinsic evolutionary braking is buried deep under superimposed irregular processes, that prevent direct estimations of its parameters for the majority of pulsars. We re-analyze the distribution of "ordinary" radio pulsars on a F2-F1, F2-F0, F1-F0 and n_{obs}-tau_{ch} diagrams assuming their spin-down to be the superposition of a "true" monotonous term and a symmetric oscillatory term. We demonstrate that their effects may be clearly separated using simple ad hoc arguments. Using maximum likelihood estimator we derive the parameters of both components. We find characteristic timescales of such oscillations to be of the order of 1e3-1e4 years, while its amplitudes are large enough to modulate the observed spin-down rate up to 0.5-5 times and completely dominate the second frequency derivatives. On the other hand, pulsars' secular evolution is consistent with classical magnetodipolar model with braking index n ~ 3. So, observed pulsars' characteristic ages (and similar estimators that depend on the observed F1) are also affected by long term cyclic process and differ up to 0.5-5 times from their monotonous values. This fact naturally resolves the discrepancy of characteristic and independently estimated physical ages of several objects, as well as explains very large, up to 1e8 years, characteristic ages of some pulsars. We discuss the possible physical connection of long term oscillation with a complex neutron star rotation relative its magnetic axis due to influence of the near-field part of magnetodipolar torque.
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