Search

Sinter hardening of ferrous P/M materials results in parts with properties close to those of quenched and tempered steels with fewer secondary operations. Although improved sinter hardening grades of powders are becoming increasingly available, there is still a limited understanding of the relationship between properties and processing parameters. A study to assess the effect of a variation in processing parameters on mechanical properties was performed using "design of experiments" methods. The effect of variations in graphite content and cooling rate on the mechanical properties of Ancorsteel 150HP with 2 w/o copper was investigated. Yield and tensile strength, sintered hardness, tempered hardness, and elongation were measured and the data fitted to a model for each property. The model was used to find possible interaction effects between the processing variables, how they influence mechanical properties and to optimize mechanical properties. [ABSTRACT FROM AUTHOR]

Stevens-Johnson Syndrome (SJS)/Toxic Epidermal Necrolysis (TEN) is a rare and often fatal spectrum of mucocutaneous diseases usually attributable to severe adverse drug reactions. Burn units are referral centers for patients at the most extreme end of the disease continuum. Our burn center admits a much higher percentage of TEN (>30% BSA) cases than reported in most prior reviews. The purpose of this study was to analyze the diagnostic and prognostic value of variables collected on referred SJS/TEN patients. We retrospectively analyzed 94 patients admitted to our unit with a presumptive SJS/TEN diagnosis made in most cases by the referring center. Most of the diagnoses were clinical. Fifty of the 94 patients underwent biopsy when the clinical diagnosis was questionable. Of the 50 patients who underwent biopsy, 18 (36%) received an alternative diagnosis. Analysis was therefore limited to 76 patients, i.e. 44 patients felt to have firm clinical diagnoses plus 32 patients with diagnoses confirmed by biopsy. Mean age was 54.3 years (17-93) and overall gender ratio was 43 F vs. 33 M (56.6% vs. 43.4%). Mean LOS was 15.2 days (1-48) and overall mortality was 23.7% (18/76). Univariate analysis revealed percent body surface area (%BSA) did not show statistically significant association with mortality. Histopathological correlation for diagnosis is not standardized across institutions worldwide. Due to challenges in the diagnosis of SJS/TEN and the high incidence of error in clinical diagnosis, it is recommended that all patients with presumed SJS/TEN receive skin biopsies with H&E and direct immunofluorescence. We propose a diagnostic approach in order to address this need. Lack of association between %BSA and mortality suggests that all biopsy-proven SJS/TEN cases belong in specialty centers due to the unstable nature of the disease and risk for rapid progression., (Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.)