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Biomedical subjects

Iu V Popov

Publications and source records attributed to Iu V Popov.

At least 19 recordsLinked to original sources
PubMed2002

[Audiometry in critical frequency bands of hearing].

The analysis of the choice and distribution of the fixed frequencies in the course of audiometry and mechanisms of automatic regulation in the hearing system (HS) gave grounds to suppose that: 1) HS is rather a multichannel system than a single channel, the number of channels being equal to the number of frequency critical acoustic bands (that is 24); 2) not one but 24 mechanisms of threshold hearing adaptation operate in HS, one for each critical hearing band; 3) the number of fixed frequencies at which audiometry is made (125 Hz-8 kHz) should be 21 while now it is 9 and these frequencies should not change by ostave, but must correspond to central frequencies of critical hearing bands this number of frequencies being optimal.

Audiometry↗
PubMed1997

[A hydrodynamic model of a cochlea with a discrete basilar membrane].

The hydrodynamic model of a cochlea (dimensions 520 x 120 x 100 (mm)), with the basilar membrane (BM) consisting of 50 discrete resonance links in the frequency band from 1 Hz to 128 Hz was constructed. Two ways of giving harmonic and impulse's signals at the model were used; a) through the membrane of the vestibular window (directly through the filled model liquid along the BM) and b) through the thread fastened to the basal part of the BM (by the travelling wave on the BM). It was shown that in the first case the transmission's time to apical part of the BM equals 0.8 ms and in the second--several seconds. The conclusion is that the main hydrodynamic processes of sound's coding in a cochlea are the processes according to the Helmholtz's resonance theory, but not Békésy's travelling wave theory.

Basilar Membrane↗
PubMed1991

[Total anomalous drainage of pulmonary veins into the coronary sinus (clinical aspects, diagnosis and surgical treatment)].

Total anomalous drainage of the pulmonary veins into the coronary sinus is a complicated congenital heart disease which takes a particularly severe course at early age. Its diagnosis is based on the discovery of overfilling of pulmonary circulation on radiography in a cyanotic patient, atrial septal defect and distended coronary sinus on echocardiography, and, in some cases, anomalous drainage of the pulmonary veins into the coronary sinus. The final diagnosis may be established during selective pulmonary arteriography. Operations were performed on 12 patients with this pathological condition under extracorporeal circulation and hypothermia with good results. In patients over one year of age the operation consisted in widening the atrial septal defect with resection of the part of the interatrial septum between the defect and the superior border of the coronary sinus and closure of the newly formed defect with a graft and transposition of the coronary sinus and the abnormally draining pulmonary veins into the left atrium. In patients under one year of age the interatrial septum was not resected.

Adolescent↗
PubMed1990

[Photomodification of autologous blood in surgery].

The use of the method of autologous blood photomodification in surgery is discussed on basis of generalized experience of the Leningrad Research-Practical Center of Blood Photomodification (3,000 procedures conducted in over 2,000 patients). The current state of the problem, the main mechanisms of the therapeutic action of the procedure, and the clinical efficacy of the method in various surgical diseases are dealt with. The possible complications and the means of their prevention are deal with. The methodological aspects of research are discussed. The authors define the main problems which must be solved in order to raise the efficacy of using photomodification of autologous blood in surgery.

Blood↗
PubMed1988

[Early alcoholization and drug abuse behavior as a manifestation of delinquency in children and adolescents].

Long-term investigation of 115 children and adolescents of either sex with delinquent behavior is presented. Of these, in 81 an early alcoholization and in 29 drug abuse behavior has been revealed. The first experience with toxic substances and alcohol was generally inspired by persons of the same age. Of wines, spirits prevailed, and of toxic substances gasoline and acetone-containing stuff. The level and direction of social activity, especially at leisure, were major prognostic factors. Twenty-four percent of patients had a steady level of social adaptation with their signs of the disease satisfactorily compensated.

Adolescent↗
PubMed1988

[Morphometric analysis of the mitochondria of cardiomyocytes in normal states and in postischemic reperfusion].

The analysis of mean values of mitochondrial parameters calculated according to the formula measuring the number of particles in 1 cubic micron has suggested that in cardiomyocytes during reperfusion mitochondria can be described as ellipsoids, whose length is comparable with the length of sarcomeres, and unaffected cardiomyocytes as long bent structures. The volume of one mitochondrion and the surface of mitochondria in 1 cubic micron of sarcoplasm in control and affected cardiomyocytes were identical. The surface of one mitochondrion during postischemic reperfusion was decreased and the number of mitochondria in 1 cubic micron of sarcoplasm was higher than in the control. It is suggested that the damage of cells is associated with an increase in the number and total volume of mitochondria as a result of their lacing and an increase in the volume of each "daughter" mitochondrion up to the volume of the initial mitochondria.

Animals↗
PubMed1987

[Assessment of the state of the myocardium from the histochemical detection of dehydrogenases in the presence of granular diformazan].

Histochemical tests for dehydrogenases in isolated rat myocardia have shown the level of granular diformazan to correlate with the presence of fat drops in cardiomyocytes. Using a semiquantitative method they developed for assessing myocardial status from histochemical tests for dehydrogenases (glutamate, isocitrate, lactate, succinate, beta-hydroxybutyrate NADH, or NADPH dehydrogenases), the authors found that demonstration of granular diformazan in such tests is not associated with alterations in the state of particular dehydrogenases but is indicative of fatty dystrophy.

Animals↗
PubMed1987

[Quantitative ultrastructural criteria of myocardial damage in postischemic reperfusion].

Swollen clarified mitochondria were found during postischemic reperfusion in cardiomyocytes with and without signs of myofibril relaxation. The values of morphometric parameters of mitochondria were similar in both groups of cells studied. Mean indexes characterizing the condition of cardiomyocyte mitochondria may serve as quantitative criteria of the severity of myocardial damage: surface to volume, ratio, visual index of mitochondrial condition and relative volume density, i.e. volume density with respect to control cell volume.

Animals↗
PubMed1986

[Pathocharacterologic reactions in adolescence].

Pathocharacterological reactions have been studied in a long-term follow-up (9-12 years) of 58 youths aged 14-18 years. These reactions were observed more frequently (P less than 0.05) in teenagers with a premorbid accentuation of the character of the epileptoid, unstable, hyperthymic, or hysteroid types. The studied reactions are classified in accordance with the characterological principle. Recommendations on rehabilitation of the above group of patients are presented. The questions of the differential diagnosis are considered. On the whole a stable social adaptation was observed in 72.4% of patients despite a considerable duration of pathocharacterological reactions in some of them.

Adolescent↗
PubMed1985

[Effectiveness of protecting the myocardium against ischemia with a normothermic cardioplegic solution and creatine phosphate].

The protective effects of cardioplegic solutions (CS) containing creatine phosphate (CP) were studied in a rat heart model of cardiopulmonary bypass and ischemic cardiac arrest. Isolated rat hearts were subjected to a 3-minute coronary infusion with CS containing CP in normothermic (37 degrees C) and hypothermic (4-6 degrees C) regimes. In the normothermia group, the postischemic functional recovery was 70-75% of the preischemic control value, while the cellular ATP and CP content was reduced but insignificantly. By contrast, in the hypothermia group, the postischemic functional recovery was markedly depressed, with the tissue high-energy phosphate content being appreciably lowered. The data obtained confirm high efficacy of CP-containing cardioplegic solutions administered under normothermia conditions.

Adenosine Triphosphate↗
PubMed1985

[Stages and systematics of psychopathies and psychopath-like disorders of a non-psychotic nature in adolescents (multi-year study)].

A long-term study covered 121 adolescents with psychopathies and psychopathy-like disturbances. A stable level of social adaptation was ascertained in 83.3% of the adolescents with acute affective reactions, in 69.6% of the adolescents with a pathocharacterological development and reactions, in 14.3% of the patients with a psychogenic pathological formation of the personality, in 13.2% of the patients with psychopathies and in 42.9% of the patients with psychopathy-like disorders of exogenic-organic genesis. The following stages of depsychopathization were specified: adaptive transformation, effacement, depsychopathization as a result and clinical recovery. A multiaxial classification of the studied disturbances is proposed. Apart from the traditional nosological and syndromological characteristics, it reflects pathocharacterological peculiarities, the stages of the time-course of psychic disorders and the degree of social adaptation.

Adaptation, Psychological↗