51 research outputs found
A Case of Successful Medical Treatment of Ventricular Tachycardia in a Patient With Ischemic Heart Disease and Heart Failure
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 Quantum Hall State: Excitons, Spin-Waves and Spin-Textures
We study the theory of intrinsic photoluminescence of two-dimensional
electron systems in the vicinity of the 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 . 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 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
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
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
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
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
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
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