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The reliability of AlGaInP double-heterostructure (DH) light-emitting diodes (LEDs) operating typically at 600 nm has been studied. To investigate degradation, accelerated aging at ambient temperatures of 50, 75 and 125°C has been carried out for over 5000 h. The activation energy of homogeneous degradation was determined to be 0.8 eV and an extrapolated half-life in excess of 106 h was estimated at an ambient temperature of 20°C. Copyright © 2000 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

We present a review of the current literature involving fractures of the pisiform and hook of the hamate. This is highlighted by two cases in which the fracture lines are seen only on the reverse oblique wrist radiograph, a view obtained with the wrist in a supinated rather than a pronated position. These fractures are not seen on standard two or three view wrist examination. Both of these fractures were initially missed in the emergency department. Serious sequelae can result from both of these injuries and can be avoided if diagnosed acutely. The reverse oblique radiograph can be quick, cost-effective, and diagnostic in this setting. If properly treated by immobilization or excision, the results can be excellent.