Free Tarsal Graft and Free Skin Graft for Lower Eyelid Reconstruction.

Purpose: To determine whether reconstruction of lower eyelid defects involving the eyelid margin with a free tarsal graft and an overlying free skin graft, without retention or provision of any vascular support, would yield acceptable functional and cosmetic results.

Methods: We present here a clinical series of 4 patients treated between April 2019 and September 2019 who underwent reconstruction of large postcarcinoma excision, eyelid-margin-inclusive eyelid defects. Surgery was performed by the same surgeon (J.

Secretory Carcinoma of the Lacrimal Gland: A Rare Case Report.

Secretory carcinoma is a salivary gland malignancy that recapitulates secretory carcinoma of the breast, along with its shared ETV6-NTRK3 gene fusion. Characterization of histopathologic, immunohistochemical, and molecular genetic features of this neoplasm has led to reclassification of a heterogeneous group of salivary gland carcinomas as secretory carcinoma and to identification of this neoplasm in other gland-containing tissues. The authors describe a 52-year-old man who presented with a 2-week history of diplopia and a well-circumscribed right orbital mass.

Relationships between the generalized functional method and other methods of nonimaging optical design.

The recently developed generalized functional method provides a means of designing nonimaging concentrators and luminaires for use with extended sources and receivers. We explore the mathematical relationships between optical designs produced using the generalized functional method and edge-ray, aplanatic, and simultaneous multiple surface (SMS) designs. Edge-ray and dual-surface aplanatic designs are shown to be special cases of generalized functional designs.

Thermodynamic efficiency of solar concentrators.

The optical thermodynamic efficiency is a comprehensive metric that takes into account all loss mechanisms associated with transferring flux from the source to the target phase space, which may include losses due to inadequate design, non-ideal materials, fabrication errors, and less than maximal concentration. We discuss consequences of Fermat's principle of geometrical optics and review étendue dilution and optical loss mechanisms associated with nonimaging concentrators. We develop an expression for the optical thermodynamic efficiency which combines the first and second laws of thermodynamics.

Thermodynamic efficiency of solar concentrators.

The optical thermodynamic efficiency is a comprehensive metric that takes into account all loss mechanisms associated with transferring flux from the source to the target phase space, which may include losses due to inadequate design, non-ideal materials, fabrication errors, and less than maximal concentration. We discuss consequences of Fermat's principle of geometrical optics and review étendue dilution and optical loss mechanisms associated with nonimaging concentrators. We develop an expression for the optical thermodynamic efficiency which combines the first and second laws of thermodynamics.