Tuning of tunneling current noise spectra singularities by localized states charging

We report the results of theoretical investigations of tunneling current noise spectra in a wide range of applied bias voltage. Localized states of individual impurity atoms play an important role in tunneling current noise formation. It was found that switching "on" and "off" of Coulomb interaction of conduction electrons with two charged localized states results in power law singularity of low-frequency tunneling current noise spectrum ($1/f^{\alpha}$) and also results on high frequency component of tunneling current spectra (singular peaks appear).Comment: 7 pages, 4 figure

Atrial Fibrillation Triggers in Patients with Coronary Artery Disease and Subclinical Thyrotoxicosis

We examined 202 patients with paroxysms of symptomatic and asymptomatic atrial fibrillation (AF), some of whom suffered from coronary artery disease (CAD) andsubclinical thyrotoxicosis (ST). Healthy individuals acted as a comparison group. It was revealed that in all studied groups, extrasystoles and paroxysms of reciprocal atrioventricular orthodortic and nodal tachycardia was the role of the triggering factors of AF. In patients with ST without CAD and in healthy persons, the paroxysms of tachycardia are short and unstable. When CAD combined with ST, the number of extrasystoles and AF paroxysms is significantly higher than only in ST and in healthy individuals. It was found that in patients with asymptomatic AF the total number of extrasystoles and paroxysms of tachycardia is greater than in the case of symptomatic. Thus, the identification of concomitant subclinical thyrotoxicosis in a patient with CAD should alert the clinician to the development and progression of atrial fibrillation. It should be given great attention to screening thyroid pathology in patients with CAD. Keywords: atrial fibrillation, coronary artery disease, subclinical thyrotoxicosis

Asymptomatic Lone Atrial Fibrillation in Pregnant Women

We examined 43 pregnant women with paroxysms of asymptomatic lone atrial fibrillation. It was revealed that the increasing of the gestational age leads to increase of number of single, paired and group supraventricular extrasystoles; single and paired ventricular extrasystoles; number and duration of paroxysms of atrial fibrillation. However, the number of extrasystoles and paroxysms of arrhythmia decreased to baseline values after delivery. Thus, it was proved that pregnancy contributes to the increase of paroxysms of lone atrial fibrillation due to the increased influence of modulating components on the triggering extrasystoles. The importance of the method of 24-hour ECG monitoring in the detection of arrhythmia in pregnant women is emphasized. Keywords: lone atrial fibrillation, extrasystole, pregnancy