Kinetics of nickel particle formation on silicon substrate with a buffer layer of niobium nitride.

The size, form and distribution function of catalyst particles define the quality of synthesized arrays of carbon nanotubes. In this work, we study the kinetics of catalyst particle formation from the thin nickel film (9 nm) deposited on the silicon substrate (SiO/Si) with a buffer layer of niobium nitride at the temperature of 880 °C. In the experiment, we have obtained the time dependences of the average radius, average height and concentration of nickel particles.

[High-resolution ECG in assessment of myocardial functional state in patients with ischemic heart disease and resultant cardiac dilatation].

High resolution signal-averaged ECG (SAECG), echocardiography and 24-hour Holter ECG monitoring were used in the study of 30 patients (mean age 56-/+2 years) with coronary heart disease and stable class II-IV angina (group 1) and 66 patients (mean age 45-/+1 years) with dilated cardiomyopathy of ischemic origin (group II). SAECG was used for detection of late ventricular potentials and calculation of time-voltage and velocity parameters of P-waves. Disturbances of myocardial de- and repolarization indicative of pronounced hemodynamic left atrial overload associated with elevated left ventricular end diastolic pressure were revealed.

[The connection between late ventricular potentials and ventricular arrhythmias in hypertension patients with different forms of myocardial hypertrophy].

Aim: To estimate the incidence of late ventricular potentials (LVP) and their implication in cardiac arrhythmia.

Materials And Methods: 53 patients with blood hypertension stage II (mean age 50 +/- 1 years) having symmetric (n = 23) and asymmetric (n = 15) left ventricular hypertrophy as well as 15 patients free of hypertrophy underwent conventional 12-lead ECG, Holter monitoring, echocardiography and late potentials (LP) recording using signal-averaged high resolution ECG.

Results: LP occurred more often in asymmetric myocardial hypertrophy than in symmetric one.

[The possibility for the presumed detection of the obstructive lesion of the coronary arteries in stenocardia patients by the data from circadian ECG monitoring and stress tests].

Whether 24-h ECG monitoring (ECGM) may be used in detection of multiple arterial obstructions in anginal patients and to compare diagnostic efficacy of ECGM and bicycle exercise (BE) in prediction of 2 or 3 lesions was investigated in 137 patients subjected to ECGM and selective coronarography. 117 of them did bicycle exercise. The number of episodes of painful and painless myocardial ischemia in ECGM was related with the extension and depth of the coronary flow obstruction.

[Fluctuations in the stenocardia threshold of patients with ischemic heart disease].

In twenty-eight men (the mean age 49.3 +/- 3.2 years) with different clinical varieties of angina pectoris, analysis was made of the heart rate and the grade of ischemic depression of the ST segment, associated with anginous attacks seen during bicycle ergometry and other physical exercises in the course of daily cardiomonitoring.

[The hemodynamic effect of closed mitral recommissurotomy based on data from manometry in the heart chambers and from echocardiography].

The hemodynamic effect of operation was studied in 181 patients after closed mitral recommissurotomy on the basis of findings of intraoperative manometry in the heart chambers and echocardiography. Lower pulmonary hypertension was noted in 87.9% and that of the diastolic gradient on the mitral valve in 86.

[Comparison of exercise test and ECG monitoring results in women with ischemic heart disease].

To diagnose myocardial ischemia and differentiate the chest pain syndrome in 20 females with coronary heart disease and effort angina pectoris, exercise test and ECG monitoring were performed. Their results were then compared. The informative value of 24-hour ECG monitoring was higher than that of bicycle ergometry in detecting the objective signs of ischemia in patients with effort angina.

[Painless episodes of ST segment displacement and the possibility of their prevention in patients with exertion-induced stenocardia].

Sixty patients with stable exercise-induced angina were examined by 24-hour Holter monitoring. It was found that an average of 51.7% of significant episodes of ischemic ST-segment depression failed to be accompanied by anginal episodes during the whole day.

[Disorders of cardiac rhythm and conduction during attacks of stenocardia].

Heart rhythm and conductivity disorders, developing during anginal attacks, and their relation to the pattern of myocardial ischemia have been studied, using 24-hour ECG monitoring, in 60 patients with stable angina, and in 67 patients with unstable angina. Heart rhythm and conductivity disorders at the ventricular level were much more common in Prinzmetal's angina (73%), as compared to the attacks involving ST depression (10%). Their incidence depended both on the direction and magnitude of ST displacement.

[Determining the vasospastic origin of stenocardia attacks on the basis of 24-hour ECG monitoring].

The pattern of anginal attacks was evaluated, using 24-hour ECG monitoring, in 67 patients with angina at rest, as compared to 60 patients with angina of effort. In most patients, ischemic ECG changes developed in the presence of unchanged heart rate at rest or heart rate increment of less than 0.25 of the daily peak, and disappeared as heart rate increased.

[Myocardial electrical activity and hemodynamic indices in the early stage of the rehabilitation of myocardial infarct patients].

Available indirect methods were employed to examine 52 patients with a history of myocardial infarction and 18 normal subjects by the end of the early rehabilitation period. Hemodynamic overload of the left atrium was revealed. The main hemodynamic parameters and processes marking contractile and electrical myocardial functions did not return to normal.

[Wedge pressure in the pulmonary vein and artery].

Analysis of the results of measurements of the pressure in pulmonary veins and left auricle in 143 patients with mitral stenosis during the operation and the registration of the wedge pressure in the pulmonary veins during catheterization in 62 of 105 patients of another group enabled the authors to conclude that there was no autonomous pulsation of the pulmonary veins. The pressure after occlusion with a catheter of the pulmonary vein branches and the pulmonary artery does not reflect the true hemodynamic condition in the occlusion basin. The data obtained should be considered as artificial phenomena determined by the method islet.

[Myocardial contractile capacity of the right ventricle in lesser circulation hypertension and in right ventricular insufficiency].

The informative value of some indices of myocardial contractility, calculated from curves of pressure in the right ventricle and pulmonary artery, was determined in 119 patients suffering from mitral heart disease with various grades of pulmonary hypertension in 25 patients who did not have a heart disease. The dependence of these indices on the grade of pulmonary hypertension and severity of the clinical symptoms of right-ventricular insufficiency was also studied. The Siegel-Sonnenblick contractility index proved to be the most informative index of myocardial contractile function.