Effect of secondary annealing process on critical current density in highly textured Bi-2212 superconducting system

Bi-2212 samples prepared by a solid-state reaction technique have been grown from the melt using the laser floating zone method. After annealing the as-grown bars, the samples showed a good grain alignment and a high transport critical current density. Secondary annealing processes were performed on the annealed samples with the aim of producing Bi-2212 phase controlled decomposition. Hence, the Bi-2201 phase and the secondary phases, which act as effective pinning centers, were obtained with the secondary annealing process. After these thermal treatments, the transport critical current densities of samples significantly increased, when compared to the annealed ones. The maximum critical current density was achieved when the samples were subjected to secondary annealing at 680°C for 168 h with an improvement of ~80%, compared to the annealed ones. Moreover, it was found that magnetization of the secondarily annealed samples was also increased. The magnetic critical current densities in these secondary annealed samples were about 3 times higher than the values obtained for the annealed ones. These results clearly indicate that the secondary annealing processes lead to the formation of effective pinning centers in the bulk material.The authors acknowledge financial support from the Gobierno de Aragón (Grupos de Investigacion Consolidados T12 and T87) and the Spanish MINECO-FEDER (Project MAT2013-46505-C3-1-R).Peer Reviewe

Case Report - HAEMOPHILUS APHROPHILUS BRAIN ABSCESS IN THE FIRST DECADE

This report presents a case of brain abscess due to Haemophilus aphrophilus in a six-year old boy. He was admitted to our hospital suffering from left-sided weakness. The initial radiological diagnosis was an intracranial abscess. Purulent material was obtained by puncturing the subcortical lesion and the sample was cultured on conventional media. H. aphrophilus was isolated in pure culture, identified according to conventional methods and confirmed by Becton Dickinson Laboratory (BBL) crystal system. After surgical drainage and eight weeks of antibiotic therapy, the neurological findings improved. The presented case is an example of H. aphriphilus causing brain abscess in the first decade without cardiac predisposition and with good outcome

Proteus syndrome: A case report and review of the literature

Proteus syndrome is a rare hamartomatous condition comprising overgrowth of some part of the body in association with various cutaneous, neurovascular, musculoskeletal, and other organ systems. In some cases, there is a family history. The case presented is that of a 6-year-old boy with left hemihypertrophy, wide-spread capillary hemangiomatosis in the extremities, a pigmented nevus on the right forearm, macrosyndactyly of the second and third fingers, together with a history of urolithiasis. The literature on this rare syndrome is reviewed

Leukoencephalopathy with a mild clinical course: A case report

PubMed ID: 10397361Infantile-onset leukoencephalopathy of van der Knaap type is manifested by initially normal or near normal neurological findings despite infantile- onset megalencephaly and magnetic resonance imaging evidence of severe white matter affection. Until this entity was recently described, these cases were usually presented under the heading of atypical variants of Alexander disease. To date 63 individuals have been reported in English literature. We report a four-year-old boy presented in the first months of life with progressive megalencephaly, delay in walking, clumsiness, convulsions and magnetic resonance imaging evidence of diffuse swelling of white matter, cystic cavitations in frontal, temporal and parietal lobes.Infantile-onset leukoencephalopathy of van der Knaap type is manifested by initially normal or near normal neurological findings despite infantile-onset megalencephaly and magnetic resonance imaging evidence of severe white matter affection. Until this entity was recently described, these cases were usually presented under the heading of atypical variants of Alexander disease. To date 63 individuals have been reported in English literature. We report a four-year-old boy presented in the first months of life with progressive megalencephaly, delay in walking, clumsiness, convulsions and magnetic resonance imaging evidence of diffuse swelling of white matter, cystic cavitations in frontal, temporal and parietal lobes

Autonomic nervous system functions in obese children

Childhood obesity is a complex syndrome, probably due to the multiplicity of contributing factors, contradictory literature information about etiology, prognosis, prevention and treatment. In the recent reports, autonomic nervous system (ANS) dysfunction has been documented in adult obesity. Autonomic nervous system functions in obese children are not clear. This study was planned to investigate autonomic nervous system function in childhood (7-13 years of age) obesity. Study and control groups consisted of 33 simple obese (23 boys and ten girls, mean age 9.5 +/- 1.4 years) and 30 healthy children (18 boys and 12 girls, mean age 10.1 +/- 1.8 years), respectively. Four non-invasive autonomic nervous system function tests (Orthostatic test, Valsalva ratio, 30/15 ratio, Heart rate responses to deep breathing) and general ophthalmic examination were performed on both groups. The difference between the obese and control groups was found statistically significant in Valsalva ratio, 30/15 ratio and Heart rate responses to deep breathing (P 0.05). Ophthalmic examinations were normal. The result of these tests suggested normal activity of sympathetic, and hypoactivity of parasympathetic nervous system, implying parasympathetic nervous system dysfunction as a risk factor or associated finding in childhood obesity. (C) 2000 Elsevier Science B.V. All rights reserved

Merosin-negative congenital muscular dystrophy: Magnetic resonance spectroscopy findings

PubMedID: 15862197Congenital muscular dystrophies (CMD) are heterogenous group of muscle disorders with autosomal recessive inheritance. Merosin deficiency has been identified in some patients with CMD all of whom also had white matter abnormalities on MRI. In postmortem studies, the brain showed extensive myelin pallor with a spongy appearance of white matter and moderate astrocytosis or demyelination. Direct assessment of neuropathologic aspects of MN-CMD such as demyelination is possible with MR spectroscopy (MRS). Although previous reports have described several neuro-imaging findings of this disease, MRS findings have not been reported in literature. In this case, we report MRS features of a 4-year old girl with MN-CMD. MRS of brain demonstrated that N-acetylaspartate (NAA)/Creatine (Cr) ratio was normal. Increased Choline (Cho)/Cr and Myo-inositol (MI)/Cr ratios were obtained. These findings were interpreted as demyelination and gliosis of white matter. © 2004 Elsevier B.V. All rights reserved

Superconductivity and magnetic properties of Bi-2212/Ag textured composites prepared at different growth speeds

Resumen del trabajo presentado a la: "3rd International Conference on Superconductivity and Magnetism" celebrada en Estambul (Turquia) del 29 de abril al 4 de mayo de 2012.Superconductivity and magnetic properties of Bi2Sr2CaCu2Ox/3 wt.%Ag textured composite materials prepared by a LFZ melting technique at different growth speeds (5, 15, 30 and 60mm/h) have been studied. X-ray diffraction patterns showed that in all cases the Bi-2212 phase is the major one. The magnetization measurements have been carried out as a function of the magnetic field up to 10 kOe. Jc values of the samples were calculated by using the Bean’s model. The results indicate that the different growth speeds have significant effects on the JC values of samples. We found that the maximum critical density of JC is 4.42x105 A/cm2 at 10K for the 15 mm/h grown sample. The best results, both physical and magnetic properties, have been obtained for samples grown at 15 mm/h.Peer reviewe