51 research outputs found

    A Case of Successful Medical Treatment of Ventricular Tachycardia in a Patient With Ischemic Heart Disease and Heart Failure

    Get PDF
    The pathogenetic mechanisms of arrhythmias, including  high-grade ventricular  arrhythmias (including non-sustained ventricular  tachycardia),  in patients with coronary  heart disease may be different. Therefore, the characteristics  of ventricular arrhythmias must be considered  based on the totality of data, taking  into account all the available features. The importance  of a personalized approach  to the management of a patient with coronary  heart disease who had extensive myocardial  infarction 18.5 years ago,  followed  by mammary  coronary  artery bypass  grafting, aneurysmectomy and the development of heart failure with a low ejection fraction, in whom ventricular arrhythmias occurred against the background of a stable course of coronary disease , but after emotional stress, is reflected in this work. An extended examination, as well as a detailed study of the nature of ventricular arrhythmias, made it possible  to determine  the main provoking factor and select an individualized pathogenetic treatment with a good  antiarrhythmic result that persists for several years of observation.  Conducting mental tests and psychological questioning can be recommended for patients with coronary  heart disease  and  chronic  heart failure as an additional  examination to assess  the contribution  of the psycho-emotional factor  to arrhythmogenesis after excluding the ischemic and sympathetic  nature of ventricular ectopia. It is incorrect to consider that all ventricular arrhythmias  in patients with coronary heart disease are ischemic in nature, and in some clinical situations this statement is even erroneous

    Theory of Photoluminescence of the ν=1\nu=1 Quantum Hall State: Excitons, Spin-Waves and Spin-Textures

    Full text link
    We study the theory of intrinsic photoluminescence of two-dimensional electron systems in the vicinity of the ν=1\nu=1 quantum Hall state. We focus predominantly on the recombination of a band of initial ``excitonic states'' that are the low-lying energy states of our model at ν=1\nu=1. It is shown that the recombination of excitonic states can account for recent observations of the polarization-resolved spectra of a high-mobility GaAs quantum well. The asymmetric broadening of the spectral line in the σ\sigma_- polarization is explained to be the result of the ``shake-up'' of spin-waves upon radiative recombination of excitonic states. We derive line shapes for the recombination of excitonic states in the presence of long-range disorder that compare favourably with the experimental observations. We also discuss the stabilities and recombination spectra of other (``charged'') initial states of our model. An additional high-energy line observed in experiment is shown to be consistent with the recombination of a positively-charged state. The recombination spectrum of a negatively-charged initial state, predicted by our model but not observed in the present experiments, is shown to provide a direct measure of the formation energy of the smallest ``charged spin-texture'' of the ν=1\nu=1 state.Comment: 23 pages, 7 postscript figures included. Revtex with epsf.tex and multicol.sty. The revised version contains slightly improved numerical results and a few additional discussions of the result

    Theory of anyon excitons: Relation to excitons of nu=1/3 and nu=2/3 incompressible liquids

    Get PDF
    Elementary excitations of incompressible quantum liquids (IQL's) are anyons, i.e., quasiparticles carrying fractional charges and obeying fractional statistics. To find out how the properties of these quasiparticles manifest themselves in the optical spectra, we have developed the anyon exciton model (AEM) and compared the results with the finite-size data for excitons of nu=1/3 and nu=2/3 IQL's. The model considers an exciton as a neutral composite consisting of three quasielectrons and a single hole. The AEM works well when the separation between electron and hole confinement planes, h, is larger than the magnetic length l. In the framework of the AEM an exciton possesses momentum k and two internal quantum numbers, one of which can be chosen as the angular momentum, L, of the k=0 state. Existence of the internal degrees of freedom results in the multiple branch energy spectrum, crater-like electron density shape and 120 degrees density correlations for k=0 excitons, and the splitting of the electron shell into bunches for non-zero k excitons. For h larger than 2l the bottom states obey the superselection rule L=3m (m are integers starting from 2), all of them are hard core states. For h nearly 2l there is one-to-one correspondence between the low-energy spectra found for the AEM and the many- electron exciton spectra of the nu=2/3 IQL, whereas some states are absent from the many-electron spectra of the nu=1/3 IQL. We argue that this striking difference in the spectra originates from the different populational statistics of the quasielectrons of charge conjugate IQL's and show that the proper account of the statistical requirements eliminates excessive states from the spectrum. Apparently, this phenomenon is the first manifestation of the exclusion statistics in the anyon bound states.Comment: 26 pages with 9 figures, typos correcte

    MODERN VIEWS ON THE GENE NOTCH1 MUTATIONS ROLE FOR AORTIC COARCTATION

    Get PDF
    Aim. By the observation of aortic coarctation victims families, to reveal factors predisposing to the disease development, and to evaluate the prevalence of NOTCH1 genes mutation/replacements in patients with this kind of defect. Material and methods. Totally 68 patients included with aortic coarctation. All patients underwent echocardiographic investigation, direct and indirect manometry, multispiral computed aortography and intraoperational revision of coarctation zone. 51 patient underwent screening of 10 from 34 exones of NOTCH1 gene. Control group consisted 200 patients without IHD.Results. In more than a half of the cases coarctation coexisted with bicuspid aortic valve and in circa a hlaf of the cases there was combination of coarctation with arc or descending hypoplasia. Totally 29 NOTCH1 gene types were found. Four from those led to aminoacids exchange, of those only one, R1279H, was revealed in patients group and control group either. This type was much more prevalent in patients with aortic coarctation comparing to control group (p<0,05).Conclusion. The most important factors in coarctation development are heredity (33,8%) and complicated pregnancy (57,4%). The exchange of R1279H in gene NOTCH1 was much more prevalent in patients with the defect studied and might be an associated with the disease allele

    Ventricular Tachycardia Induced by Exercise Test as a Predictor of Coronary Artery Disease Development

    Get PDF
    A long-term clinical observation of the patient with ventricular tachycardia induced by exercise test but without myocardial ischemia and coronary artery atherosclerosis based on the results of angiography in the debut of the disease is described. However, arrhythmia reproducibility during stress tests, positive drug tests with nitroglycerin and beta-blocker, results of cardiac positron emission tomography with fatty acids revealed the ischemic genesis of arrhythmias, which was indirectly confirmed by a positive antiarrhythmic effect of the therapy with a metabolic drug (treatment with a beta-blocker was impossible because there was a sinus block). Coronary angiography was performed again after 7 years during the recurrence of ventricular arrhythmia with unstable angina. Stenosis of the left anterior descending artery was revealed. The antiarrhythmic effect of myocardial revascularization was continuously positive. Therefore, ventricular tachycardia induced by exercise test in patients with risk factors even in the absence of clinical and electrocardiographic criteria for myocardial ischemia could be an early debut of coronary artery disease

    Russian sawmill modernization (a case study). Part 1: optimizing processes of low-grade timber debarking and wood chipping

    No full text
    This paper offers a new technological solution for low-quality log chipping that enables sawmills to produce wood chips efficiently and with less waste. The proposed solution for sorting wood chips helps to solve a number of urgent problems crucial to log processing. Intellectualization of sorting operations not only minimizes wood residues, but also enables the maintenance of equipment. Modifications in the chipping system, namely laser sensors and a microcontroller, help operators detect debarking defects and perform the cutting tool wear monitoring. The results of the study show that a control system intellectualization allows an efficient use of equipment and thereby serves to improve production efficiency. This study primarily concentrates on coniferous logs. The technology developed in this study is applicable to log processing equipment and can be used in debarking machines at other mills. © 2020 IWSc, The Wood Technology Society of the Institute of Materials, Minerals and Mining
    corecore