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    ABSTRACT: We have used a scanning tunneling microscope to measure both the topography and potential distribution in a current-carrying polycrystalline YBaâCuâOâminus//ital x// thin film. We find steps in the potential indicative of insulating inhomogeneities in the material which occur at boundaries between clusters of grains. These results provide the first direct correlation between the microstructure and the normal-state transport properties in these materials. The implications of these results for models used to explain the nature of superconductivity in polycrystalline high-temperature superconductors are discussed.
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    ABSTRACT: Thanks to the wider use of sonography to examine the spinal content in the neonate, normal anatomy and anomalies may be detected easily. Yet, unusual sonographic patterns are also observed. These must be differentiated from true pathologies. During a prospective study of 103 neurologically asymptomatic neonates, atypical sonographic patterns were found in 16 patients, corresponding to normal variants in 13. Nine of these 13 patients presented with a widening of the distal part of the central echo complex (one had a dilated ventriculus terminalis). Nerve roots of the cauda equina were disposed asymmetrically in three patients; the spinal cord movements were still present. In two of these babies, this distribution was associated with thin arachnoid pseudocysts. One patient presented with transitorily hyperechoic and narrow subdural spaces, probably related to neonatal dehydration. None of the 13 patients showing normal variants required any treatment. The other 3 patients (of 16) presented with equivocal entities of unknown evolution: sonographic tethered cord, fibrolipoma of the filum terminale and epidural varices. Sonography is highly accurate in evaluating the spinal cord content and aids differentiation of normal and normal variants from equivocal or pathological entities.
    Pediatric Radiology 02/1995; 25(6):429-32. DOI:10.1007/BF02019055 · 1.65 Impact Factor
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    ABSTRACT: Prenatal calcification of the inferior vena cava (IVC) and renal veins is a rare condition with unclear etiology and prognosis. It occurs with renal vein thrombosis in utero and is associated with congenital anomalies and abnormal prenatal hemodynamic status. We report a rare case of prenatal IVC and renal vein calcification in a normal neonate without any history of compromised prenatal or perinatal condition, or significant deterioration of kidney function.
    The Scientific World Journal 02/2006; 6:734-6. DOI:10.1100/tsw.2006.163 · 1.73 Impact Factor