The model shows that the transient response of the junction temperature of LEDs can be described by a multiexponential function. Each time constant of this function is approximately the product of a thermal resistance, R(th), and a thermal capacitance, C(th). The transient response of the junction temperature is measured for a high-power flip-chip LED, emitting at find protocol 395 nm, by the forward-voltage method. A two stage R(th)C(th) model is used to analyze the thermal properties of the packaged LED. Two time constants, 2.72 ms and 18.8 ms are extracted from the junction temperature decay measurement and attributed to the thermal time constant of the LED GaInN/sapphire

chip and LED Si submount, respectively. (C) 2010 American Institute of Physics. [doi:10.1063/1.3493117]“
“Endoscopes are increasingly used to examine cranial nerves in microvascular decompression (MVD) operations. The superior petrosal vein (SPV) is often purposely sacrificed to gain adequate exposure to the trigeminal nerve (TN) during MVD. Recently, the importance of preserving the SPV has been emphasized due to potential complications associated with its sacrifice. Our focus is to

study the ability to operate on the TN with preservation of the SPV by using endoscope-assisted microsurgery. We studied both cerebellopontine angles in seven cadaveric heads which vascular Proteasome inhibitor system had been injected with colored silicon material. MVD procedures were simulated using the operative microscope (Moeller-Wedel, Cologne, Germany) and two fixed-angled (0A degrees and 30A degrees) rigid endoscopes (Aesculap, PA, USA). To compare the practical advantages of microscopic MVD (MMVD) and endoscope-assisted MVD (EAMVD), we divided the approaches into four subcategories (microscopic without and with SPV sacrifice and endoscope-assisted without and with SPV sacrifice) and compared the maneuverability associated with each category using a numerical

grading system. EAMVD scored significantly better than MMVD both without and with cutting of the SPV (p < 0.001). Only in MMVD did cutting of the SPV improve the maneuverability especially in the superior quadrant of the nerve (p = 0.012). Based on the proposed scoring system, use of the endoscope in an assisted mode facilitates visualization and mobilization of the vascular loop associated with the TN without need to sacrifice Selleck LXH254 the SPV. Sacrifice of the SVP may help maneuverability in the superior quadrant of the nerve in MMVD.”
“The Bernese periacetabular osteotomy has become popular in treatment of dysplastic acetabulum. However, the polygonal shape of the osteotomy can create osseous gaps when the fragment is repositioned, especially when a large correction is needed. This study compared the stress distribution of a modified periacetabular osteotomy (spherical osteotomy with smooth and round surface) with those of traditional Bernese osteotomy using finite element analysis.