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Abstract: The magnetic and magnetoimpedance (MI) effect properties of amorphous ferromagnetic Fe77.5Si7.5B15 and (Co0.94Fe0.06)72.5Si12.5B15 were studied before and after hydrogen charging by an electrochemical method. The hydrogen charging was carried out at 25°C and in a stirred solution by applying a constant current density of 20mA/cm2 for 1h. It was found that the saturation magnetization of FeSiB wire decreased from 1.6 to 1.345T and the magnitude of the MI effect decreased from 24.4 to 7.1 after hydrogen charging. No remarkable variation in the shape of the magnetization loop and the MI effect in CoFeSiB wire were observed after hydrogenation. [Copyright &y& Elsevier]

Abstract: In this study, the magnetoimpedance, MI, effect in NiFe/Cu wire with various plated NiFe thicknesses was investigated. The MI results showed that the frequency, where the maximum MI occurs, decreases with increasing plating thickness. During the plating process some parameters such as the plating voltage, pH, and the temperature of solutions were kept constant. It was found that the thickness of the plated NiFe layer changes with plating time and the obtained plated layers are approximately 1–2, 3.5 and 10μm for 10, 60 and 180min plating times, respectively. It was found that the NiFe film thickness had a significant effect on the magnitude and frequency dependence of the MI effect. The magnitude of the MI ratio under the H =7400A/m can reach about 750% for 180min plating at 55kHz driving current frequency. [Copyright &y& Elsevier]

The dependence of the magnetization loops, coercivity, anisotropy constant, ΔE and magnetoimpedance (MI) effects in positively magnetostrictive Fe71Cr7Si9B13 amorphous wires on annealing conditions were studied. Samples were annealed at temperatures of 440°C and 460°C for durations between 0.3 and 300 min. The results indicate that progressive annealing first leads to relief of internal stresses and annealing of wires at 460°C for 60 min produces the minimum coercivity of about 1 A m−1. Further annealing increases the coercivity and anisotropy, due to partial crystallization at the surface. It was found that the anisotropy changes its direction to the circumferential direction with the surface crystallization. The maximum change in Young's modulus was measured to be about 75% in a partly surface crystalline sample. It was observed that the magnitude of the MI effect of the stress relieved sample could exceed 200% at 1 MHz. [ABSTRACT FROM AUTHOR]

The giant stress-impedance (SI) effect in as-received and furnace annealed Fe71Cr7Si9B13 amorphous wires is studied. Samples were annealed at temperature of 460 °C for times between 0.3 and 300 min to remove internal stresses. The results show that the magnetoimpedance and SI effect change sharply with annealing and a maximum stress-impedance ratio of 255% is observed in the wire annealed for 10 min under an applied tensile stress of 250 MPa. [Copyright &y& Elsevier]

Unlabelled: The objective of this study was to determine the association between intracardiac thrombosis and hereditary causes of thrombophilia, including factor V 1691 G-A (factor V Leiden, FVL) and prothrombin 20210 G-A mutations. Over a period of 3 y, genetic risk factors were evaluated in 13 consecutive children (mean age 6.27 +/- 5.44 y) with intracardiac thrombosis, diagnosed by cross-sectional echocardiography. Thrombi were localized in the left heart in four patients and the right heart in nine patients. All children had predisposing factors for thrombus formation: ventriculoatrial shunt for hydrocephalus (n = 3), indwelling catheter for chemotherapy (n = 5), cardiomyopathy (n = 2), sepsis (n = 1), homocystinuria (n = 1) and tetralogy of Fallot (n = 1). Six of the 13 children with intracardiac thrombosis were heterozygotes for FVL mutation. Three of these six children with FVL mutation had ventriculoatrial shunt for hydrocephalus, two children had cardiomyopathy and one had sepsis. None of the patients carried the prothrombin 20210 G-A mutation.Conclusion: It is recommended that FVL mutations should be investigated in all cases of intracardiac thrombosis irrespective of whether or not a predisposing factor is identified. When a predisposing factor is found antithrombotic prophylaxis may be considered in patients carrying the FVL mutation. [ABSTRACT FROM AUTHOR]

Long QT syndrome (LQTS) is characterized by prolongation of the QT interval associated with a high risk for syncope and sudden death. Jervell and Lange-Nielsen initially described LQTS in association with congenital sensorineural deafness. We have investigated the prevalence of this syndrome in a school for deaf children, evaluating by ECG 350 congenitally deaf children with an age range of 6–19 years. The corrected QT interval (QTc) was calculated by Bazett's formula. Eight children with a QTc interval >440 ms were further studied by cardiac examination, repeat ECGs (three times), Holter monitoring, echocardiography, and exercise testing. The families were assessed for a history of syncope and deafness and underwent ECG evaluations regarding lengthened QTc interval. Among these eight children only two girls aged 14 and 15 years were diagnosed as having LQTS according to Schwartz's criteria (0.57% of the 350 deaf children; 95% confidence intervals 0, ≤ p≤ 0.013). The first patient had two major criteria (QTc 483 ms and a history of syncopal attack) and one minor criteron (congenital deafness); the second also had two major criteria (QTc 613 ms and family members with LQTS) and one minor criterion (congenital deafness). Prophylactic β-blocker therapy was started in these two patients to prevent sudden death. In conclusion, this syndrome should be sought in children with syncope or a family history of it, especially those with congenital deafness. [ABSTRACT FROM AUTHOR]

Tricuspid regurgitation (TR) due to chordal rupture is a rere condition in newborns. We present a newborn with critical TR. Cross-sectional echocardiography demonstrated a dense, mobile mass localized at the tricuspid valve and resembling an atrial thrombus or myxoma. At operation, ruptured chordae tendineae of the tricuspid valve were found, forming a tangled mass. Histopathologic examination revealed collagen degeneration and calcification in the ruptured chordae, producing the hyperechoic image. It should be emphasized that ruptured chordae of the tricuspid valve might mimic a tricuspid valve myxoma or a thrombus on cross-sectional echocardiography. [ABSTRACT FROM AUTHOR]

In this study, magnetic properties of Pr0.67Ca0.33MnO3 compound were investigated in detail. The magnetization versus temperature (M-T) curve showed that this material undergoes a charge order transition at 200 K. A more pronounced FM phase appeared below 56 K. At T = 5 K, a field induced sharp step like magnetisation transition associated with phase separation was observed. However, after application of 7 T magnetic field at 5 K, the magnetic behaviour of sample was changed completely and full FM behaviour was observed. The more interesting is that the sample remains in the FM state and does not retrieve the initial magnetic state until warmed up to charge order transition temperature. Large negative magnetic entropy change (-26.18 J/(kg K) at 38 K and 5 T) was attributed to step like magnetisation transition. [ABSTRACT FROM AUTHOR]

La0.67Ca0.33MnO3 perovskite-type manganite was synthesized by high-energy ball milling raw oxides of La2O3 (purity 99.9%), CaCO3 (purity > 99%), and MnO (purity > 99%). The ratio of ball and powder weight was 10:1 and the rotating speed was set to 500 rpm. X-ray analysis indicated that La0.67Ca0.33MnO3 single phase was formed completely when milling time is up to 4 h. The peak intensity of perovskite structure decreased and a hump-like peak appeared with further milling time. When the milling time is longer than 40 h, the perovskite structure disappeared and the amorphous phase was formed completely. Scanning electron microscopy picture of 24 h milled sample showed that the particle size generally varies in a broad range from nanometer scale to a few μm. The magnetic measurements showed that ball milling samples have an inhomogeneous magnetic state and exhibit spin-glass like behavior. The significantly small magnetic entropy change and a remarkably broad temperature interval in entropy change were attributed to high degree of structural and magnetic disorder and broadening of magnetic transition. [ABSTRACT FROM AUTHOR]

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Noonan syndrome is the second most frequent congenital malformation syndrome, after Down syndrome, associated with cardiovascular abnormalities. The most prevalent cardiovascular abnormalities in Noonan syndrome are pulmonary stenosis and hypertrophic cardiomyopathy. We report the case of a 12-year-old girl with Noonan syndrome who had multiple cardiovascular abnormalities, including extensive bilateral coronary artery dilatation, valvular and supravalvular pulmonary stenosis, atrial septal defect, and mitral valve prolapse. Both coronary artery dilatation and supravalvular pulmonary stenosis, although rarely reported, are abnormalities of the cardiovascular system that may occur in Noonan syndrome. [ABSTRACT FROM AUTHOR]

The low magnetic field, H, dependence of real part of impedance, R, of as-received FeSiB and CoSiB wires have been investigated. The measurements were performed at various frequencies for various wire lengths. The wires with length longer than 7 cm show sharp peaks in the R–H curves. The combination of R–H data with M–H data indicates the existence of interaction between motion of the domain wall in the inner core and the magnetic moments in the outer shell. [Copyright &y& Elsevier]

Amorphous metallic Fe/sub 78/Si/sub 9/B/sub 13/ fibers, 50 /spl mu/m in diameter, produced by the melt extraction method, have been studied in the as-quenched state and after furnace annealing at 455/spl deg/C and 480/spl deg/C for times between 0.5 min and 50 min. Measurements of the M-H loops and field dependence of Young's modulus have shown that they behave in a way very like that of amorphous wires. The minimum coercivity of 3 A/m is greater than that found in wires, and the minimum Young's modulus (/spl sim/0.45 times the saturation value) is greater. It is suggested that the core-shell domain model applies in the as-quenched state and that stress relief followed by surface crystallization dominate the anisotropy. [ABSTRACT FROM PUBLISHER]

Cardiac hydatid cyst is an uncommon lesion. The infection, often acquired by children during play with infected dogs, is most common in sheep-raising areas of the world. We report our clinical and surgical experience in the treatment of one of the youngest reported cardiac hydatidosis patients with multivisceral involvement. [ABSTRACT FROM AUTHOR]

A 9-year-old girl was admitted because she had had palpitations for 2 years. Her electrocardiogram revealed multifocal ectopic beats with left bundle branch morphology, sinoatrial block, and first- and second-degree atrioventricular blocks. Cross-sectional echocardiography demonstrated an enlarged left ventricle and filling defects and sacculations of the posterior left ventricular wall, apex, and septum. The diagnosis of arrhythmogenic right ventricular dysplasia (ARVD) was confirmed by endomyocardial biopsy and thallium 201 scintigraphy. We present this case because of the rarity of left ventricular involvement associated with ARVD. We also emphasize the value of echocardiography in the early diagnosis of ARVD. [ABSTRACT FROM AUTHOR]

Objective: To determine the normal values of QT and QTc dispersion and the effects of sinus arrhythmia on QT dispersion in healthy children.Patients and Setting: The study was carried out in a university hospital on 372 local schoolchildren (200 male, 172 female), aged seven to 18 years.Methods: The QT and preceding RR intervals of at least one sinus beat were measured manually in a range of nine to 12 leads on standard 12 lead surface ECGs. The corrected QT interval was computed by the method of Bazett. Dispersion of QT and QTc were defined as (1) the difference between the maximum and minimum QT and QTc intervals occurring in any of the 12 leads (QTD and QTcD), (2) the standard deviation of the QT and QTc interval in the measurable leads (QT-SD and QTc-SD).Results: There was no significant difference in QT, QTc, and RR dispersion between girls and boys. Overall 53% of children had sinus arrhythmia. Although QTD and QT-SD were not affected by sinus arrhythmia, both QTcD and QTc-SD were significantly greater in children with sinus arrhythmia than in those without (QTcD: 52.9 (17.4) v 40.9 (13.1); QTc-SD: 17.5 (5.9) v 13.2 (4.0); p < 0.001).Conclusions: As calculation of QTc dispersion is affected by sinus arrhythmia, which is common in childhood, we suggest that QT dispersion should not be corrected for heart rate in children. [ABSTRACT FROM AUTHOR]

Deals with a study which examined the effect of annealing and crystallization on the magnetoelastic properties of cobalt-silicon-boron amorphous wires. Background to the study; Theoretical model; Results and discussion.

This article discusses "Familial Mediterranean Fever gene (MEFV)" mutations in patients with rheumatic heart disease. Familial Mediterranean fever (FMF) is characterised by recurrent self limited attacks of fever accompanied by inflammation of the peritoneum synovium and pleura. The gene responsible for FMF (MEFV) has been cloned recently on the short arm of chromosome 16 and more than 20 mutations have been identified. The gene product pyrin (marenostrin) is thought to control the inflammatory response by regulating the expression of some target genes that are involved in the suppression of inflammation. Thus, it was suggested that mutations in the MEFV gene prevent the normal pyrin (marenostrin) mediated negative feedback mechanism and trigger inflammation.

We report a 10-year-old boy with Mobius syndrome (MS) associated with ventricular septal defect who was delivered after an unsuccessful curettage before the 10th week of gestation. Methylergobasine which is an ergot alkaloid was also applied during the curettage procedure. Despite of the curettage procedure, the pregnancy was continued and he was delivered. His developmental milestones were delayed. On account of this case, we think that direct mechanical fetal trauma and vasoconstriction or both may cause MS. But, further extensive studies are needed to verify this hypothesis. [ABSTRACT FROM AUTHOR]

Familial Mediterranean fever (FMF) should be kept in mind in the differential diagnosis of recurrent pericarditis and mutation analysis should be considered, especially in patients of Mediterranean origin. [ABSTRACT FROM AUTHOR]

In this study, NiFe nanowires were deposited on Au-coated porous anodic alumina oxide (AAO) template by electrochemically. Scanning electron microscopy showed that wires have diameters of about 250-310 nm and length of 50-60 μm. NiFe nanowire arrays embedded in AAO were mechanically polished until nanowires appeared. Later, electrical contacts were made to a single nanowire using a focused ion beam (FIB) system. Magnetoimpedance (MI) properties of single nanowire were investigated, and nearly 3.5 % MI was observed at 4 GHz driving current frequency. [ABSTRACT FROM AUTHOR]