Akira Nakajima

Superhydrophobic surfaces are those with a water contact angle greater than 150°, and these are desired for various industrial products. Such surfaces have been achieved for boehmite and silica films, which were roughened by the sublimation of aluminum acetylacetonate during calcination. The Figure shows the shape of a water droplet on such a silica film.

Transparent superhydrophobic thin films with TiO2 photocatalyst were prepared by utilizing a sublimation material and subsequent coating of a (fluoroalkyl)silane. The transparency of the films decreased with increasing TiO2 concentration, which was attributed to the size difference of the starting materials. The film with only 2 wt % TiO2 maintained higher contact angle than the film without TiO2 after 1800-h outdoor exposure, the accumulation of stain being avoided due to TiO2 photocatalysis. T

Polarized Raman-scattering spectra are obtained from oriented single crystals of yttria-doped ${\mathrm{CeO}}_{2}$. The temperature and dopant dependencies of Raman spectra strongly suggest that many structures in the Raman spectra of yttria-doped ${\mathrm{CeO}}_{2}$ are induced by the defect space including an ${\mathrm{O}}^{2\mathrm{\ensuremath{-}}}$ vacancy. The contribution to the frequency distributions of Raman-active modes from the whole Brillouin zone are estimated from the imaginary pa

Immunoglobulin A (IgA) promotes health by regulating the composition and function of gut microbiota, but the molecular requirements for such homeostatic IgA function remain unknown. We found that a heavily glycosylated monoclonal IgA recognizing ovalbumin coats <i>Bacteroides thetaiotaomicron</i> (<i>B. theta</i>), a prominent gut symbiont of the phylum Bacteroidetes. In vivo, IgA alters the expression of polysaccharide utilization loci (PUL), including a functionally uncharacterized molecular f

The regulation of inflammatory responses within adipose tissue by various types of immune cells is closely related to tissue homeostasis and progression of metabolic disorders such as obesity and type 2 diabetes. G-protein-coupled receptor 43 (GPR43), which is activated by short-chain fatty acids (SCFAs), is known to be most abundantly expressed in white adipose tissue and to modulate metabolic processes. Although GPR43 is also expressed in a wide variety of immune cells, whether and how GPR43 i

The photoinduced wettabilities of both water and hexadecane on a polycrystalline anatase TiO2 thin film were investigated. An amphiphilic surface was produced on the polycrystalline TiO2 thin film by UV illumination as on the rutile single crystal. Further illumination of the amphiphilic surface increased the hexadecane contact angle gradually and produced a hydrophilic−oleophobic surface. The total energies of the illuminated UV light to produce and terminate the amphiphilic state were independ

Hydrophobic coatings have been applied to various industrial items. However, their expected properties cannot always be obtained for practical use by merely decreasing their surface energies. Various cases require precise design and control of a coating's structure and chemical composition. This paper briefly reviews recent studies of transparent hydrophobic coating design. It specifically addresses superhydrophobic coatings.

We examined the change in photoluminescence spectra of porous Si when it is oxidized then deoxidized chemically. After both steps, photoluminescence shifted to higher frequencies and increased in intensity. These shifts to higher frequencies indicate the photoluminescence is a result of the quantum size effect. Moreover, the increase in photoluminescence intensity after oxidation suggests that termination by hydrogen on the porous Si surface does not always play a key role in the photoluminescen