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This study aimed to determine the relationship between geometric and dosimetric agreement metrics in head and neck (H&N) cancer radiotherapy plans. A total 287 plans were retrospectively analyzed, comparing auto-contoured and clinically used contours using a Dice similarity coefficient (DSC), surface DSC (sDSC), and Hausdorff distance (HD). Organs-at-risk (OARs) with ≥200 cGy dose differences from the clinical contour in terms of Dmax (D0.01cc) and Dmean were further examined against proximity to the planning target volume (PTV). A secondary set of 91 plans from multiple institutions validated these findings. For 4995 contour pairs across 19 OARs, 90% had a DSC, sDSC, and HD of at least 0.75, 0.86, and less than 7.65 mm, respectively. Dosimetrically, the absolute difference between the two contour sets was <200 cGy for 95% of OARs in terms of Dmax and 96% in terms of Dmean. In total, 97% of OARs exhibiting significant dose differences between the clinically edited contour and auto-contour were within 2.5 cm PTV regardless of geometric agreement. There was an approximately linear trend between geometric agreement and identifying at least 200 cGy dose differences, with higher geometric agreement corresponding to a lower fraction of cases being identified. Analysis of the secondary dataset validated these findings. Geometric indices are approximate indicators of contour quality and identify contours exhibiting significant dosimetric discordance. For a small subset of OARs within 2.5 cm of the PTV, geometric agreement metrics can be misleading in terms of contour quality. [ABSTRACT FROM AUTHOR]

Ion beams with energies in the range 1–2 keV are used to sputter neutral Zr atoms from a polycrystalline surface. Laser induced fluorescence detection is used to obtain angular distributions of sputtered neutrals as a function of ion impact direction, ion mass, ion energy, and spin–orbit state of the exiting atoms. About 40% of the sputtered atoms are excited. Angular distributions depend weakly on ion mass and energy. The angular distributions are fitted well by a modified form of the Roosendaal and Saunders model of sputtering. [ABSTRACT FROM AUTHOR]

Presents a study that investigated triisopropyl indium (TIPIn) as an alternative to trimethyl indium for use in chemical-beam epitaxy. Characterization of TIPIn precursors; Details on growth modulated-beam mass spectrometry experiments; Assessment of InGaAs growth and material properties.

Cases of pyogenic granuloma in pregnant women, nonpregnant women, and men were evaluated for the detection of estrogen and progesterone receptor proteins by immunoperoxidase staining. Immunostaining for estrogen receptors revealed a marked immunoreactivity of the endothelium within lesional tissue and in the overlying mucosal epithelium in many cases. Progesterone receptor immunoreactivity was only present within the epithelium, where it was much less than that of estrogen receptor immunoreactivity in both quantity (proportion of positive cells) and intensity. No characteristic staining pattern or significant quantitative difference among the three study groups could be discerned. These findings suggest that the quantity of estrogen or progesterone receptors in pyogenic granuloma is not the determining factor in the pathogenesis of this lesion. Rather, such a role may be attributed to the levels of circulating hormones. The levels of estrogen and progesterone are markedly increased in pregnancy and could therefore exert a greater effect on the endothelium of the pyogenic granuloma.

Laser-induced fluorescence spectra of Zr atoms sputtered by ion bombardment have been obtained for the (5)F degrees (1) ? (3)F(2) transition at 595.5 nm. The isotopic shift of (91)Zr is found to be -70 +/- 40 MHz relative to the (90)Zr peak. A discrepancy in literature values for the hyperfine constants of the (5)F degrees (1) state is also resolved.