Silicon nanowire possesses great potential as the material for renewable energy harvesting and conversion. The significantly reduced spectral reflectivity of silicon nanowire to visible light makes it even more attractive in solar energy applications. However, the benefit of its use for solar thermal energy harvesting remains to be investigated and has so far not been clearly reported. The purpose of this study is to provide practical information and insight into the performance of silicon nanowires in solar thermal energy conversion systems. Spectral hemispherical reflectivity and transmissivity of the black silicon nanowire array on silicon wafer substrate were measured. It was observed that the reflectivity is lower in the visible range but higher in the infrared range compared to the plain silicon wafer. A drying experiment and a theoretical calculation were carried out to directly evaluate the effects of the trade-off between scattering properties at different wavelengths. It is clearly seen that silicon nanowires can improve the solar thermal energy harnessing. The results showed that a 17.8 % increase in the harvest and utilization of solar thermal energy could be achieved using a silicon nanowire array on silicon substrate as compared to that obtained with a plain silicon wafer.

Acquired cholesteatoma is a chronic inflammatory disease characterized by both hyperkeratinized squamous epithelial overgrowth and bone destruction. Toll-like receptor (TLR) activation and subsequent inflammatory cytokine production are closely associated with inflammatory bone disease. However, the expression and function of TLRs in cholesteatoma remain unclear.We observed inflammatory cell infiltration of the matrix and prematrix of human acquired cholesteatoma, as well as dramatically increased expression of TLR4 and the pro-inflammatory cytokines TNF-α and IL-1β. TLR2 exhibited an up-regulation that was not statistically significant. TLR4 expression in human acquired cholesteatoma correlated with disease severity; the number of TLR4-positive cells increased with an increased degree of cholesteatoma, invasion, bone destruction, and hearing loss. Moreover, TLR4 deficiency was protective against experimental acquired cholesteatoma-driven bone destruction and hearing loss, as it reduced local TNF-α and IL-1β expression and impaired osteoclast formation by decreasing expression of the osteoclast effectors receptor activator of nuclear factor (NF)-κB ligand (RANKL) and tartrate-resistant acid phosphatase (TRAP). TLR2 deficiency did not relieve disease severity, inflammatory responses, or osteoclast formation. Moreover, neither TLR2 nor TLR4 deficiency had an effect on antimicrobial peptides, inducible iNOS,BD-2 expression or bacterial clearance. Therefore, TLR4 may promote cholesteatoma-induced bone destruction and deafness by enhancing inflammatory responses and osteoclastogenesis.

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Temporal fascia, tragus perichondrium, and tragus cartilage-perichondrium composite grafts are all suitable for myringoplasty after a minor tympanic membrane perforation. However, cartilage-perichondrium composite graft material for myringoplasty has superior long-term benefits in regard to both hearing improvements and tympanic membrane morphology, which are especially evident in cases with large perforations.

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