15 research outputs found
A comparative analysis of Patient-Reported Expanded Disability Status Scale tools.
BACKGROUND: Patient-Reported Expanded Disability Status Scale (PREDSS) tools are an attractive alternative to the Expanded Disability Status Scale (EDSS) during long term or geographically challenging studies, or in pressured clinical service environments. OBJECTIVES: Because the studies reporting these tools have used different metrics to compare the PREDSS and EDSS, we undertook an individual patient data level analysis of all available tools. METHODS: Spearman's rho and the Bland-Altman method were used to assess correlation and agreement respectively. RESULTS: A systematic search for validated PREDSS tools covering the full EDSS range identified eight such tools. Individual patient data were available for five PREDSS tools. Excellent correlation was observed between EDSS and PREDSS with all tools. A higher level of agreement was observed with increasing levels of disability. In all tools, the 95% limits of agreement were greater than the minimum EDSS difference considered to be clinically significant. However, the intra-class coefficient was greater than that reported for EDSS raters of mixed seniority. The visual functional system was identified as the most significant predictor of the PREDSS-EDSS difference. CONCLUSION: This analysis will (1) enable researchers and service providers to make an informed choice of PREDSS tool, depending on their individual requirements, and (2) facilitate improvement of current PREDSS tools.University of Southampton and National Institute of Health Research (NIHR)
El Correo gallego : diario polĂtico de la mañana: Ano LIX NĂşmero 20384 - 1937 xuño 15
NiP
alloys are very often used in industry, due to their outstanding
performance in corrosion and wear. Alloys with high phosphorus content
(≥16 atom % P) are amorphous and show high corrosion resistance
in both neutral and acidic solutions irrespective of the presence
of chloride ions. The reason for this behavior is attributed to the
formation of a “P-enriched surface layer” whose exact
nature is still under debate. In this work, an iterative algorithm
based on the application of maximum entropy method on nondestructive
angle-resolved X-ray photoelectron spectroscopy data has been applied
to the investigation of the surface layer grown on Ni18P alloys following
mechanical polishing and anodic polarization in sulfate solutions.
The results show that the outermost region of the examined alloy has
a complex layered structure: (1) an uppermost hydrocarbon contamination
layer about 1 nm thick, which includes also adsorbed water; (2) a
nickel (poly)Âphosphate layer of about 1 nm; (3) a highly phosphorus-enriched
interface being about 2 nm thick with a marked phosphorus concentration
gradient, from 70 to 20 atom %; and (4) bulk alloy with the stoichiometric
composition. These findings, together with the chemical state of the
different phosphorus compounds, allow us to conclude that the high
corrosion and wear resistance of NiP alloys might be ascribed to the
presence of a thin, self-repairing nickel (poly)Âphosphate layer grown
on a strongly P-enriched interface. Because the Auger parameter of
P at the interface is similar to that of elemental P, it might be
also concluded that the interface is enriched in elemental phosphorus