Abstract— We describe a spatial extension to the CIELAB color metric that is useful for measuring color reproduction errors of digital images. To compute the error, digital color images are spatially filtered using a pattern‐color separable method and then converted into the CIELAB representation. Over patterned regions of the image, the reproduction errors measured using the spatial extension of CIELAB correspond to perceived color errors better than errors computed without the spatial extension. Over uniform spatial regions of the image, errors computed with the extension are equal to errors computed using the standard CIELAB formulae.

Icariin can be a potential promoting compound for cartilage tissue engineering, and it can be a substitute for the use of some growth factors. The long history and extensive cases of safe use in China, Japan and Korea make it more attractive.

Osteoporosis is associated with decreased bone density and increased bone fragility, but how this disease affects alveolar bone healing is not clear. The objective of this study was to determine the extent to which osteoporosis affects the jaw skeleton and then to evaluate possible mechanisms whereby an osteoporotic phenotype might affect the rate of alveolar bone healing following tooth extraction. Using an ovariectomized mouse model coupled with micro–computed tomographic imaging, histologic, molecular, and cellular assays, we first demonstrated that the appendicular and jaw skeletons both develop osteoporotic phenotypes. Next, we demonstrated that osteoporotic mice exhibit atrophy of the periodontal ligament (PDL) and that this atrophy was accompanied by a reduction in the pool of osteoprogenitor cells in the PDL. The paucity of PDL-derived osteoprogenitor cells in osteoporotic mice was associated with significantly slower extraction socket healing. Collectively, these analyses demonstrate that the jaw skeleton is susceptible to the untoward effects of osteoporosis that manifest as thinner, more porous alveolar bone, PDL thinning, and slower bone repair. These findings have potential clinical significance for older osteopenic patients undergoing reconstructive procedures.