Search

A newly developed severe plastic deformation (SPD) technique, i.e. repetitive upsetting (RU), is employed to improve the strength and ductility of a Mg-Gd-Y-Zr alloy. During the RU processing, dynamic recrystallization occurs in the Mg alloy, which leads to a significant grain refinement from 11.2 μm to 2.8 μm. The yield strength (YS), ultimate tensile strength (UTS) and elongation increase simultaneously with increasing RU passes. The microstructural evolution is affected by processing temperatures. Dynamic recrystallization prevails at low temperatures, while dynamic recovery is the main effect factor at high temperatures. Texture characteristics gradually become random during multiple passes of RU processing, which reduces the tension-compression asymmetry of the Mg-Gd-Y-Zr alloy. [ABSTRACT FROM AUTHOR]

Background: This study assessed the relationship between asthma burden and asthma severity in France, Italy, and Spain. Methods: Adult asthmatics, 18-55 years of age, completed a questionnaire while visiting a respiratory physician in 1998 and 1999. Asthma severity was categorized by physicians as intermittent, mild persistent, moderate persistent, or severe persistent according to Global Initiative for Asthma (GINA) guidelines. Results: Totals of 282 patients in France, 500 in Italy, and 296 in Spain entered the study. There were few differences between the three countries in the asthma symptom burden. Most patients with persistent asthma had used inhaled corticosteroids in the previous 14 days. Unexpectedly, 35% (Italy) to 83% (Spain) of patients with intermittent asthma also had used inhaled corticosteroids. In Spain, visits to the emergency department were more frequent (OR 7.0, 95% CI 4.9-10.0 with Italy as reference) and the costs of emergency care in all asthma severity categories were up to 10 times higher than in Italy and France. The frequency of hospitalizations did not differ systematically between the three countries. Conclusions: Inadequate control of asthma symptoms among patients with severe persistent asthma could not be entirely explained by under-prescribing of asthma medications. The use of inhaled corticosteroids by patients with intermittent asthma might reflect misclassification of asthma severity, possibly due to difficulty in interpreting the GINA guidelines. The relatively high cost of emergency care in Spain does not appear to be related to greater asthma severity or poorer symptom control, but may be a feature of the Spanish health care system.