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BackgroundMulticenter studies rely on data derived from different institutions. Forms can be designed to standardize the reporting process allowing reliable comparison of data.ObjectiveThe purpose of the report is to provide a standardized method, developed as a part of a multicenter study of vertically transmitted HIV, for assessing chest radiographic results.Materials and methodsEight hundred and five infants and children were studied at five centers; 3057 chest radiographs were scored. Data were entered using a forced-choice, graded response for 12 findings. Quality assurance measures and inter-rater agreement statistics are reported.ResultsThe form used for reporting chest radiographic results is presented. Inter-rater agreement was moderate to high for most findings, with the best correlation reported for the presence of bronchovascular markings and/or reticular densities addressed as a composite question (kappa = 0.71). The presence of nodular densities (kappa = 0.56) and parenchymal consolidation (kappa = 0.57) had moderate agreement. Agreement for lung volume was low.ConclusionThe current tool, developed for use in the pediatric population, is applicable to any study involving the assessment of pediatric chest radiographs for a large population, whether at one or many centers.

Magnetic tunnel junctions have applications in a range of spin-electronic devices. The functional properties of such devices are critically dependant on the nanoscale morphology of the insulating barrier (usually only a few atomic layers thick) that separates two ferromagnetic layers. Here we report atomic-resolution three-dimensional visualization of magnetic tunnel junctions with an aluminum oxide barrier, using three-dimensional atom probe analysis and cross-sectional high resolution electron microscopy. Our results on barriers with a range of degrees of oxidation have enabled a mechanism for the oxidation to be proposed. Low oxidation times result in discrete oxide islands and further oxidation leads to a more continuous, but nonstoichiometric, barrier. Post-deposition annealing leads to an increase in the barrier area and near stoichiometric chemistry with evidence that oxidation proceeds along the top of grain boundaries in the underlying CoFe. Our three-dimensional visualization enables us to show that even perforated barriers (formed at shorter oxidation times) can have reasonable transport properties. [ABSTRACT FROM AUTHOR]

Reports on the use of neutron diffraction to determine the location and concentration of carbon in Nd[sub2]Fe[sub17] and in a silicon (Si) substituted alloy. Performance of magnetization measurements; Data on the powder diagrams for the Si-doped specimens; Discussion.

Reports on the Mössbauer experiments for Sm[sub2]Fe[sub14]Al[sub3]C[suby] and Nd[sub2]Fe[sub14.54]Si[sub2.46]C[suby] to study the effect of carbon on the magnetic properties of the compounds. Amount of alpha-iron and the presence of multiple phases in the systems; Information on the hyperfine field of the compounds; Intensity of various subspectra for different carbon concentration.

Presents information on a study that prepared a series of rare-earth iron intermetallic carbide compounds by the reaction of powders with methane gas. Experimental details; Results and discussion on the study.

Studies the hard magnetic properties of melt spun Nd(Fe,M)[sub12] nitrides and carbides. Soft sources to which low coercivities were attributed to; Factors affecting their hard magnetic properties; Description of coercivity.

Presents a study which examined the microstructure of as-cast neodymium-rich neodymium-iron-boron magnets. Experimental details; Results; Discussion.

Presents a study which examined the magnetic viscosity behavior in several hard magnets with different magnetization reversal mechanisms including barium ferrite powders. Experimental details; Results and discussion; Conclusions.

Studies magnetic and structural properties of melt-spun rare-earth transition-metal intermetallics with thorium manganese[sub12] structure. Method of the study; Results and discussion; Conclusion.

Discusses a study that examined the magnetic and structural properties of quaternary RCo[sub4-x]Fe[subx]B alloys with R= neodymium, samarium, erbium and with magnetometry and x-ray diffraction. Manner of obtaining coercivities; Process of making ribbon samples; Techniques used for making splat-cooled samples for the neodynium-iron-boron system.

Deals with a study that detailed magnetic measurements for iron-rich ternary alloys with certain compositions. Description of ternary alloys; Impact of the use of light rare earth on the alloy; Use of rapid-quenching techniques in the production of single-phase 10:1:1 alloys.

Presents a study on the magnetic hardening of melt-spun nanocomposite Nd[sub2]Fe[sub14]B/Fe magnets. Step taken to increase coercivity; Ways in which the magnetic properties are influenced by the substitution of neodymium with other rare earth elements; Cause of the differences in coercivities.