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Ellipsometry is widely used to determine the thermo-optical properties of thin polymer films. However, if the thermo-optic coefficient (TOC) and the linear thermal expansion coefficient (LTEC) are to be used to determine the temperature coefficient of electronic polarizability (TCEP) in thin polymer films, their values must be determined with the greatest possible accuracy, as both have the opposite effect. In this article, we analyze changes in ellipsometric parameters resulting from changes in the thin film temperature in order to develop a data analysis method for temperature-dependent spectroscopic ellipsometry that will facilitate the accurate determination of thermo-optical parameters, including the TCEP, in polymer thin films. As practical application examples, we identified optimal spectral windows to accurately determine the thermo-optical parameters of 50 to 150 nm-thick PMMA thin films deposited on Si and SiO2 substrates. The influence of thin-film thickness on the accuracy of TOC and LTEC determination is discussed. [ABSTRACT FROM AUTHOR]

This paper presents some results of investigations on aluminum oxide Al2O3 thin films prepared by the atomic layer deposition method on polished monocrystalline silicon. It has been described how the technological parameters of the deposition process, like the number of cycles and substrate temperature, influenced the optical properties and morphology of prepared thin films. Their physical and optical properties like thickness, uniformity and refractive index have been investigated with spectroscopic ellipsometry, atomic force microscopy and UV/vis optical spectroscopy. [ABSTRACT FROM AUTHOR]

The aim of this study was to produce nanocomposite polymer fibres, consisting of a matrix of polyacrylonitrile (PAN) and a reinforcing phase in the form of SiO2/TiO2/Bi2O3 nanoparticles, by electrospinning the solution. The effect of the nanoparticles and the electrospinning process parameters on the morphology and physical properties of the obtained composite nanofibres was then examined. The morphology of the fibres and the dispersion of nanoparticles in their volume were examined using scanning electron microscopy (SEM). All of the physical properties, which included the band gap width, dielectric constant and refractive index, were tested and plotted against the concentration by weight of the used reinforcing phase, which was as follows: 0%, 4%, 8% and 12% for each type of nanoparticles. The width of the band gap was determined on the basis of the absorption spectra of radiation (UV-vis) and ellipsometry methods. Spectroscopic ellipsometry has been used in order to determine the dielectric constant, refractive index and the thickness of the obtained fibrous mats.

A case of a 59-year-old man with recurrent angina associated with ST-segment elevation in leads II, III, aVF and V4R-V6R, cardiogenic shock and complete atrio-ventricular block, is presented. Coronary angiography was normal. Therapy with calcium channel blockers was effective. Difficulties in the treatment of patients with variant angina are discussed.

Background: Clinical value of electrocardiographic features of torsade de pointes (TdP) has not yet been well established., Aim: To compare the mode of onset and ECG characteristics of slow (s-TdP) and fast (f-TdP) episodes of TdP., Methods: 54 episodes of TdP recorded in 6 patients (5 females, one male, mean age 64.4 years) with acquired long QT syndrome were analysed. Baseline rate of TdP (V-V), ventricular rate variability (VRV), coupling interval (CI) at the onset of TdP, prematurity index (PI) and the first cycle length (FCL) were compared between 31 s-TdP (<200 beats/min) and 23 f-TdP (> or =220) episodes of TdP., Results: Episodes of f-TdP were preceded by a significantly faster basal rhythm than s-TdP (R-R interval: 922 ms vs 1062 ms, p=0.03). QT interval was almost identical in both groups (517 ms vs 515 ms, NS, respectively). No significant differences were noted in the CI of the initiating beat (488 ms vs 472 ms, NS) nor in the PI (0.53 vs 0.47, NS). TdP was most frequently spontaneously terminated by a gradual slowing of the tachycardia rate; 58% of s-TdP and 39% of f-TdP episodes stopped in this way. An acceleration of ventricular rate before termination of TdP was noted in 32% of s-TdP and in 26% of f-TdP episodes. Episodes of f-TdP were longer than s-TdP episodes (mean of 19.7 vs 6.7 ventricular complexes per one episode, p=0.0003). There were significant differences in the VRV parameter (p=0.0005) and FCL (p=0.004) between both types of TdP. Faster TdP were characterised by lower ventricular rate variability (VRV - 19.5 msec) than s-TdP (VRV - 39.4 msec). Of 54 episodes of TdP, 9 (16.6%) degenerated into VF and required DC shock. Of 31 s-TdP episodes, one (3.2%) degenerated into VF compared with 8 (34.7%) episodes of f-TdP (p<0.04)., Conclusions: Episodes of fast TdP were characterised by a longer duration, shorter first cycle of the arrhythmia and lower ventricular rate variability than episodes of slow TdP. Fast episodes of TdP were preceded by faster baseline rhythm before TdP. Faster TdP more frequently degenerated into VF than slower episodes.

A case of 78 year-old woman with primary hypothyroidism and atrial fibrillation treated with sotalol, complicated with cardiac arrest due to ventricular fibrillation (VF) and torsade de pointes (TdP) is presented. The QT interval was prolonged to 660 msec. Episodes of polymorphic ventricular tachycardia and VF recurred. Lidocaine, tosylate bretylate and betabloker successfully eliminated VF but short-lasting episodes of TdP were still present. Increased doses of hormonal substitution with thyroid hormones successfully eliminated malignant ventricular arrhythmias and normalised QT interval to 430 msec.