Development of a mathematical model for propagation of ultrasonic waves in thick-walled cylinders in the presence of a thermal gradient - Case of axial scanning.

Investigation of variations in ultrasonic wave velocity and travel path in the presence of thermal gradient is essential for accurate ultrasonic testing of engineering components which are subjected to high temperatures. In this paper, a mathematical model is developed for calculation of the wave velocity and travel path in thick-walled hollow cylinders that are subjected to thermal gradients during axial scanning. The cylinder is assumed to be homogeneous, isotropic, and made from Structural steel. The independent variables are incidence angle, cylinder outer radius, and temperature of the cylinder's inner surface. The results obtained from the theoretical model indicate that the wave velocity and travel path are highly sensitive to inner-surface temperature of the cylinder. Moreover, at incidence angles much lower than critical angles (especially at low temperatures), the wave velocity is almost independent of the incidence angle and the travel path is very close to a straight line. However, as the incidence angle approaches one of the critical angles, the wave travel path considerably deviates from a straight line. An experimental setup was designed and built in-house for measuring the longitudinal wave velocity in a steel hollow cylinder in the presence of a thermal gradient. The preliminary experimental results were found to be in good agreement with theoretical results.

In vitro toxicity assay of cisplatin on mouse acute lymphoblastic leukaemia and spermatogonial stem cells.

Testicular cancer is the most common cancer affecting men in reproductive age, and cisplatin is one of the major helpful chemotherapeutic agents for treatment of this cancer. In addition, exposure of testes cancer cells to cisplatin could potentially eliminate tumour cells from germ cells in patients. The aim of this study was to evaluate the effect of cisplatin on viability of mouse acute lymphoblastic leukaemia cell line (EL-4) and neonatal mouse spermatogonial cells in vitro. In this study, the isolated spermatogonial stem cells (SSC) and EL-4 were divided into six groups including control (received medium), sham (received DMSO in medium) and experimental groups which received different doses of cisplatin (0.5, 5, 10 and 15 µg ml(-1) ). Cells viability was evaluated with MTT assay. The identity of the cultured cells was confirmed by the expression of specific markers. Our finding showed that viability of both SSC and EL-4 cells was reduced with the dose of 15 µg/ml when compared to the control group (P ≤ 0.05). Also, the differences between the IC50 in doses 10 and 15 µg/ml at different time were significant (P ≤ 0.05). The number of TUNEL-positive cells was increased, and the BAX and caspase-3 expressions were upregulated in EL4 cells for group that received an effective dose of cisplatin). In conclusion, despite the dramatic effects of cisplatin on both cells, spermatogonial stem cells could form colony in culture.

Effects of the angiotensin receptor blocker Valsartan (Valsacor®) on arterial pressure, indices of myocardial diastolic function and global longitudinal strain in patients with uncontrolled arterial hypertension.

UNLABELLED: The objective of this study was to evaluate the effects of Valsartan (Valsacor®) on arterial pressure (AP) and indices of myocardial diastolic and global function in patients with uncontrolled arterial hypertension (AH). MATERIAL AND METHODS: 60 patients (39 men and 21 women, mean age 63.9 ± 10.8 years, P > 140/90 mmHg with a background of combined antihypertensive therapy) were involved in the study. Valsartan (Valsacor®) was added to the standard therapy. The follow-up continued for three months, with clinical visits at initiation and completion of the study. The echocardiographic (EchoCG) evaluation included measurements of left ventricular and left atrial dimensions and function via longitudinal strain and Doppler-analysis of the transmitral blood flow. RESULTS: The administration of Valsartan (Valsacor®) resulted in a significant improvement in the antihypertensive control in the studied patients. The mean values of the baseline systolic blood (SBP) and diastolic blood (DBP) pressure in the studied group of patients were 174.9 ± 17.9 (range 150­230) mmHg and 97.5 ± 6.4 (range 85­110) mmHg, respectively. The mean SBP and DBP values at the end of the third month of the follow-up period were 139.1 ± 10.9 (range 120­180) mmHg and 84.9 ± 6.2 mmHg, respectively, at p < 0.05, compared to the baseline. The results of the echocardiographic analysis revealed significant differences in the dynamic performance of the indices: telesystolic dimension of the left ventricle, deceleration time (DT), E', E/E' ratio and values of longitudinal strain. The observed dynamic performance reflects favour­able responses of the indices for diastolic function and longitudinal strain in the studied patients. CONCLUSION: Valsartan (Valsacor®), used as an adjunct to the standard antihypertensive therapy in patients with insufficiently controlled AH, leads to optimisation of the AP values and improvement of the indices of diastolic and global myocardial function, with a very good safety profile.

SDS-coated Sepabeads SP70-modified by 4-[(E)-3-phenylallylidene) amino] benzenethiol as new efficient solid phase for enrichment and determination of copper, nickel, chromium, and zinc ions in soil, plants, and mint water samples.

A sensitive and simple method based on modification of Sepabeads SP70 by 4-((E)-3-phenylallylidene) amino) benzenethiol for the simultaneous preconcentration of trace amounts of copper (Cu), nickel (Ni), chromium (Cr), and zinc (Zn) ions in some real samples has been reported. The metal ions which are retained as respective complexes on solid phase were eluted with 8 ml of 4 M nitric acid. The influences of different analytical parameters including pH, ligand amount and Sepabeads SP70 and SDS amount, eluting solutions, and sample volume on metal ions recoveries were investigated. The effects of matrix ions on the retentions of the analytes were also examined. The recoveries of analytes were generally >95% with RSD between 0.74 and 0.88. The proposed method has been successfully applied for the determination of these metals in some real samples with complex matrices.

A preconcentration procedure for copper, nickel and chromium ions in some food and environmental samples on modified Diaion SP-850.

A sensitive and simple method for the simultaneous preconcentration of trace amount of Cu2+, Ni2+ and Cr3+ ions in some real samples has been reported. In this method these elements are adsorbed as respective complex with Bis(2-hydroxyacetophenone)-1,2-propanediimine (BHAPPDI) on Diaion SP-850 and the retained metal ions are eluted using 8 ml of 4 M nitric acid. The influences of the analytical parameters including pH, solid phase ingredients amount and condition of eluting solution and sample volume were investigated. The effects of matrix ions on retentions of the analytes were also examined. The recoveries of analytes were generally higher than 90% with a relatively low RSD. The method has been successfully applied for these metal ions contents evaluation in some food and environmental samples.

Preconcentration and separation of trace amount of copper (II) on N1, N2-bis(4-fluorobenzylidene)ethane-1,2-diamine loaded on Sepabeads SP70.

A sensitive and simple method for the preconcentration of copper (II) ions has been reported. The method is based on the adsorption of copper ion N(1), N(2)-bis(4-fluorobenzylidene)ethane-1,2-diamine loaded on Sepabeads. The sorpted copper content was eluted by 8 ml of 4M nitric acid in acetone. The influences of the analytical parameters including pH and sample volume were investigated. The interference effects of matrix ions on the retentions of the copper (II) ions were also examined. The recovery of understudy analyte was generally higher than 95%. The method has been successfully applied to the evaluation of copper contents in some real samples including water samples, vegetable samples and milk samples.

[Examination of ontogenetic-morphologic growth of cholinergic receptor system in isolated preparation of human trachea in vitro]. / Ispitivanje ontogenetsko-morfoloskog razvitka kolinergicnog receptornog sistema na izoliranom preparatu humane traheje in vitro.

Morphologic growth of cholinergic bronchial respiratory system was examined at live and dead newborns. Tracheal smooth musculature was examined at 18 experimental preparations taken by the autopsy after exiting from different factors. Samples were divided into three groups based on gestational weeks. First group: from 23-29 gestational weeks (immature, N=5); second group: from 30-37 gestational weeks (premature, N=7); third group: from 38-41 gestational weeks (mature, N=6). Based on morphological examination of isolated preparations human trachea fingings are the following: in 23-29 week are found nerve endings with axo-axonal synapses mainly at ramification phase of lungs blood vessels net, without trachea bronchial innervations with axo-axonal synapses, and with perichondrial localization. In 30-37 gestational weeks axo-xonal synapses are found in between glands acinus's and vessels net, and also emphatic choline reactivity at lung ganglions: this suggests existing of cholinergic system at alive newborns. At 38-41 gestational weeks exists a wealthy nerve neuromuscular net in smooth tracheal musculature with different vesicles. Choline reactivity is emphasized peri and intrachondrial at lamina propria, at most around sensory glands and in smooth musculature. This suggests that there is no choline reactivity at epithelium and of existence of cholinergic system in tracheal bronchial smooth musculature.

[The effect of acetylcholine, dopamine, histamine and serotonin in the tracheal smooth muscle in the response with desquamative and non-desquamative epithelium of respiratory pathways in vitro]. / Istrazivanje in vitro delovanja acetilkolina, dopamina, histamina i serotonina na odgovor trakealne glatke muskulature sa deskvamiranim i nedeskvamiranim epitelom.

In this paper we have examined the receptor bronchial system in newly born children with desquamative and with preserved epithelium of aerial pathways. The response was followed in: acetylcholine, dopamine, histamine and scrotonin in various concentrations (10(-4), 10(-3), 10(-2), 10(-1)). The tonus of the tracheal smooth muscle was examined in 29 tracheal preparations, taken by autopsy after excitation from various factors. On the basis of functional investigation it has been established as follows: acetylcholine had caused the response of the bronchial smooth muscle with desquamative epithelium in a significant way (p < 0.01), in contrast to cases which were treated with unimpaired epithelium (p > 0.1). The effect of dopamine was significant in cases with desquamative epithelium (p < 0.05), in contrast to cases where epithelium was preserved (p > 0.1). The effect of histamine was also significant in cases with desquamative epithelium of respiratory pathways (p < 0.01), in contrast to cases where epithelium was preserved. Cases with desquamative epithelium in serotonin have reacted significantly (p < 0.01), despite cases which had no impaired epithelium of respiratory pathways (p > 0.1). Obtained results show that the response of the tracheal discs with desquamative epithelium of respiratory pathways was significant (p < 0.01), despite cases which had preserved the epithelium of respiratory pathways (p > 0.1). This suggest that various mediators with local effect are released during desquamation of epithelium which increase thus the bronchial reactibility of respiratory pathways.

[In vitro effects of acetylcholine, dopamine, histamine and serotonin on tracheal smooth muscle response during hypersecretion and normal secretion of tracheal glands]. / Istrazivanje in vitro djelovanja acetilholina, dopamina, histamina i serotonina na odgovor glatke muskulature traheje sa hipersekrecijom i normosekrecijom trahealnih zljezda.

It is expressed in vitro answer of the soft musculature of the tracheobronchial system of the newborns from 12 to 18 weeks of the gestation, with the hypersecretion and normosecretin of the tracheal gland. On 30 tracheal preparations taken by autopsy' of the dead children, was followed-up the answer of the tracheal soft musculature (SMT) on acetylcholine, dopamine, histamine and serotonine in the concentrations from 110(-4), 10(-3), 10(-2), 10(-1) M/L. The results illustrate that acetylcholyne, and histamine in the mentioned concentrations provoked the statistically significant answers of GMT with the hypersecretion and normosecretion of the tracheal glands (p < 0.01). On the contrary, dopamine and serotonine have not provoked statistically significant answers of these structures (p > 0.1), what illustrates that also dopaminergic and serotoninergic receptors at tracheobronchila system are not sufficient developed in this age of life. The answers of the tracheal-bronchial rings with hypersection of the tracheal glands a little more emphasized than the answers with normosecretion of the glands, but this difference is not statistically significant (p > 0.1).

[An in vitro study of tracheal smooth muscle response to ethanol in neonates with respiratory distress syndrome]. / Invitro ispitivanje odgovora glatke muskulature traheje na etanol kod novorodencadi sa respiratornim distres sindromom (RDS).

The aim of this paper was the registration of the answers of the smooth musculature of the trachea at the different concentrations of ethanol, at the gestationary weeks of the newborns with the respiratory distress syndrome. In vitro examination was worked at the nonhuman preparations of the trachea of the newborns at autopsy material, the same material of the trachea and the lungs is fixed on 10% puferized formaline for the pathomorphologic examinations (RDS). The incubation of the preparation is performed on the water bath with Kreps solution, with the constant aerozation (O2 95% and CO2 5%). The answers are registered by means of the Transducer Statham UC2 at higher canal written physiography Watanabe HSE 6600. The preparations are treated with various concentrations of ethanol 96% (0.2 ml, 0.5 ml and 1.0 ml). From the received results we came to the conclusion that the effect of ethanol in the various concentrations at the smooth musculature of the trachea in the newborns with RDS, is demonstrated the contractile or the relaxing effect without statistic significance in various gestational weeks (p > 0.05).

[Early hemodynamic changes in chronic obstructive pulmonary disease with initial respiratory failure]. / Ranni khemodinamichni promeni pri khronichnata obstruktivna belodrobna bolest s nachalna dikhatelna nedostat'chnost.

The chronic hypoxemia seems to play an important role in the pathogenesis of hemodynamic disorders in chronic obstructive pulmonary disease (COPD). The aim of the study was to follow-up the changes in pulmonary hemodynamics in COPD with mild respiratory failure. 78 COPD patients with Ist and IId degree of respiratory failure were investigated. The following investigations were carried out: two--dimensional echocardiography, spirometry, arterial blood gases and acid-base balance. In 18 of COPD patients a right heart catheterization was performed and the following indices were determined: mean pulmonary arterial (PA) pressure, pulmo-capillary resistance, teledyastolic right ventricular volume. The echocardiography showed significantly higher mean PA pressure values, an initial right ventricular dilatation and right ventricular wall hypertrophy. The indices of right heart catheterization were changed, too. The pulmo-capillary resistance was significantly increased. It was the most sensitive early parameter. The mean PA pressure was increased. There was no significant difference between the mean PA pressure determined by echocardiography and by right ventricular catheterization. A relationship between the degree of hypoxemia and the hemodynamic changes was found. The long development of COPD with mild respiratory failure leads to disorders in lung microcirculation and early changes in pulmonary hemodynamics. This process worsens the prognosis of COPD and the early prevention in the complex therapy of the disease is necessary.

[Clinical and echocardiographic symptoms of mitral valve rupture]. / Klinichna i ekhokardiografska simptomatika pri ruptura na mitralnata klapa.

The diagnostic sensitivity, specificity and predicting accuracy of the various alterations, established by one-dimensional echocardiography (M-EchoC) were determined in 23 patients with rupture of mitral chordae. The diagnosis of mitral insufficiency, resulting from chordal rupture was confirmed at operation, with angiocardiography and/or bi-dimensional echocardiography. Almost all MEchoC alterations were with a relatively low sensitivity (10-50%), high specificity (60-100%) and moderately high predicting accuracy (50-80%). Of more essential diagnostic significance--moderate sensitivity and high specificity with high predictive accuracy, are the following alterations: systolic fibrillation of mitral valve, diastolic fibrillation of mitral valvular cusps, paradoxical (chaotic) movement of posterior mitral cusp during diastole. Very little sensitivity (10%) but with high specificity (100%) was established in pathological systolic echoes in the cavity of left auricle. In the majority of the cases, the rupture of mitral chordae induced grave mitral regurgitation, conditioning the various stages of cardiac insufficiency. Relatively rare is the light to moderately grave mitral regurgitation with stable hemodynamics and preserved functional capacity.

Clinical and echocardiographic characteristic of mitral valve chordae rupture.

In 23 patients with mitral valve chordae rupture, the diagnostic sensitivity, specificity and predictive accuracy of various changes found by one-dimensional echocardiography (M-echo) were determined. Nearly all M-echo changes have a relatively low sensitivity (10-50%), high specificity (80-100%) and moderate predictive accuracy (30-80%). Greater diagnostic value--moderate sensitivity, high specificity and greater predictive accuracy--is shown by the following changes: systolic mitral valve flutter, diastolic mitral leaflets flutter, paradoxical (chaotic) movement of the posterior mitral leaflet in diastole. Of very low sensitivity (10%) but high specificity (100%) are pathological systolic echo-signals in the left atrial cavity.

[Diastolic and systolic functions of the left ventricle determined by M-echocardiography in idiopathic hypertrophic cardiomyopathy]. / Diastolna i sistolna funktsiia na liavata kamera, opredelena s M-ekhokardiografiia pri idiopatichna khipertrofichna kardiomiopatiia.

The diastolic function and the correlation between pump and diastolic function of left ventricle were studied in 35 patients with idiopathic hypertrophic cardiomyopathy with subaortic stenosis via a M-echocardiographic investigation by Echoview 80 C in the routine method. The following indices were used: A. For the diastolic function: 1. Telediastolic dimension (TDD) and volume (TDV) of left ventricular cavity. 2. Dimension (DPhFF) and volume (VPhFF) of the left ventricular cavity at the end of the phase of fast filling; 3. Velocity of fast filling of the left ventricle (ml/sec) - (formula; see text) 4. Fraction of fast filling of left ventricle (%) - (formula; see text) 5. Velocity of backward motion of the anterior mitral cusp at the beginning of diastole (E - F segment); 6. Velocity of early diastolic motion of the posterior wall of left ventricle (PWLV); 7. Ratio between early diastolic (D) and systolic (S) interval of PWLV: D/S; 8. Telediastolic interval (A - C) of mitral valve; 9. Index of fast emptying of left ventricle; 10. Amplitude E - E' of mitral echogram; II. Area (cm2) between two mitral cusps in diastole. B. For the systolic (pump) function: 1. Stroke and minute volume (SV, MV) of left ventricle according to the cubic formula and Teicholz formula; 2. Telesystolic dimension (TSD) and volume (TSV) of left ventricular cavity; 3. Fraction of shortening (FS) of left ventricle (%); 4. Mean velocity of shortening of the circumferential fibres (mVcf) of left ventricle (circumf./S); 5. Ejection fraction (EF) of left ventricle (%). 6. Distance between left ventricular endocardium of interventricular septum and point E of mitral valve; 7. Fraction of systolic thickening of IVS and PWLV; 8. Velocity of systolic thickening of IVS and PWLV; 9. Amplitude of systolic motion of IVS and PWLV.(ABSTRACT TRUNCATED AT 250 WORDS)

[Therapeutic and preventive effect of oral lidocaine in extrasystole]. / Terapevtichen i profilaktichen efekt na lidokaina, prilozhen peroralno pri ekstrasistolna aritmiia.

Lidocaine, Egypt production, P. R. of Hungary, was perorally administered in an average dose of 1.8 +/- 0.38 gr daily for a period of 14.23 +/- 28.9 days to 52 patients with and average age of 61,52 +/- 12.8 with various organic cardiac diseases and ventricular extrasystolic arrhythmia. In 18 of them (47.38%) complete inhibition of arrhythmia was attained, in 10 (26.31%) a combination with another antirhythm preparation was necessary and in 10 (26.31%) the treatment had no effect. In 14 patients the peroral lidocaine form followed its intravenous infusion in acute myocardial infarction with a prophylactic aim and no rhythm disorders were observed. It was established that the unaffected cases were with proportional growth, depending on the severity of arrhythmia, classified according to the prognostic indices of Lown. In 13.46 per cent of the patients, adverse effects were observed, mainly from the gastrointestinal system. The authors think that lidocaine is a proper drug in the treatment of ventricular extrasystolic arrhythmia in the first two classes of Lown and in the prophylaxis of the patients with rhythm disorders after acute myocardial infarction.