Over the last decade, bone engineered tissues have been developed as alternatives to autografts and allografts to repair and reconstruct bone defects. This article provides a review of the current technologies in bone tissue engineering. Factors used for fabrication of three-dimensional bone scaffolds such as materials, cells, and biomolecular signals, as well as required properties for ideal bone scaffolds, are reviewed. In addition, current fabrication techniques including rapid prototyping are elaborated upon. Finally, this review article further discusses some effective strategies to enhance cell ingrowth in bone engineered tissues; for example, nanotopography, biomimetic materials, embedded growth factors, mineralization, and bioreactors. In doing so, it suggests that there is a possibility to develop bone substitutes that can repair bone defects and promote new bone formation for orthopedic applications.

The prevalence of pterygium in Dali is 39.0% among Chinese Bai aged 50 years and older. Independent associations with increasing age (>59 years), female sex, lack of education, and occupations linked to outdoor work suggest a multifactorial cause of this condition.

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Ultrasonic consolidation, an emerging additive manufacturing technology, is one of the most recent technologies considered for fabrication of metal matrix composites (MMCs). This study was performed to identify the optimum combination of processing parameters, including oscillation amplitude, welding speed, normal force, operating temperature, and fiber orientation, for manufacture of long-fiber-reinforced MMCs. A design of experiments approach (Taguchi L25 orthogonal array) was adopted to statistically determine the influences of individual process parameters. SiC fibers of 0.1mm diameter were successfully embedded into an Al 3003 metal matrix. Push-out testing was employed to evaluate the bond strength between the fiber and the matrix. Data from push-out tests and microstructural studies were analyzed and an optimum combination of parameters was achieved. The effects of process parameters on bond formation and fiber/matrix bond strength are discussed.

We study three ͑nested, parallel, and sequential cascade͒ types of schemes for doubly dressed four-wavemixing processes in an open five-level atomic system. The interaction between two dressing fields of the nested-cascade scheme is strongest and weakest for the parallel-cascade scheme, with the sequential scheme intermediate between them. Mutual-dressing processes and constructive or destructive interference between two coexisting dressed multiwave mixing channels in such a system are also considered. Investigations of these multidressing mechanisms and interactions are very useful to understand and control the generated high-order nonlinear optical signals.