[Parameters of cardiac muscle repolarization on the electrocardiogram when changing anatomical and electric position of the heart].

While discussing the diagnostic value of the single channel electrocardiogram a set of theoretical considerations emerges inevitably, one of the most important among them is the question about dependence of the electrocardiogram parameters from the direction of electrical axis of heart. In other words, changes in what of electrocardiogram parameters are in fact liable to reflect pathological processes in myocardium, and what ones are determined by extracardiac factors, primarily by anatomic characteristics of patients. It is arguable that while analyzing electrocardiogram it is necessary to orient to such physiologically based informative indexes as ST segment displacement. Also, symmetry of the T wave shape is an important parameter which is independent of patients anatomic features. The results obtained are of interest for theoretical and applied aspects of the biophysics of the cardiac electric field.

Synthesis, structure, and acidic properties of MCM-41 functionalized with phosphate and titanium phosphate groups.

Mesoporous molecular sieves Si-MCM-41 (purely siliceous) and Ti-MCM-41 (partly covered with a surface layer of TiO2) were functionalized with phosphate groups by treatment with POCl3 (denoted -MCM-41(P)and Ti-MCM-41(P), respectively). With the use of TEM, X-ray diffraction, and N2 adsorption, it was shown that the initial hexagonal structure, the high specific surface area, and porosity are retained in the functionalized materials but are not as good as in the starting materials. 1H MAS NMR and 31P MAS NMR revealed that the surface of Si-MCM-41(P) consists of silicon phosphate and pyrophosphate species. That of Ti-MCM-41(P) additionally contains titanium dihydro-, hydro-, and pyrophosphate species, the latter being predominant. TPD of adsorbed ammonia for Si-MCM-41(P) and Ti-MCM-41(P) showed that functionalization leads to the creation of moderate and strong acid sites. A combination of mesoporous structure with acidic properties makes the MCM-41 functionalized with phosphate groups promising for use as solid acid catalysts.

[Various approaches to optimizing the hemodynamics of myocardial infarct patients]. / O nekotorykh podkhodakh k optimizatsii gemodinamiki u bol'nykh infarktom miokarda.

Combined investigation of systemic and intracardiac hemodynamic parameters (radiocardiography and Fick's procedure, transvenous catheterization, and right-ventricular and pulmonary arterial blood pressure measurement) was carried out in 428 myocardial infarction patients admitted to hospital within the early hours after the attack; changes in necrotic area were monitored for 7 days (precordial ECG cartography and serial serum CPK assays). Computer-assisted combined data analysis made use of image identification techniques, the images being based on a general approximation algorithm and informative coefficient. The algorithm permitted a classification of patients' condition by left-ventricular insufficiency (a 77.4% reliability) and by the spread of necrotic area (a 72.5% reliability). The prognosis chart, constructed on the basis of comparison between actual hemodynamic values and their standard vectors, brought out optimum regimens for every parameter associated with the least risk of left-ventricular insufficiency and necrotic spread.