Nanometric optical waveguides can be made by using the dependence of surface plasmon polaritons on the gap-width between two parallel metallic plates. This waveguide can be called surface plasmon polariton gap waveguide (SPGW). The H-plane and E-plane optical circuits that consist of SPGWs have been considered. Three-dimensional numerical simulations have been performed for the nanometric optical circuits that consist of straight and branched bend SPGWs. Results show that optical circuits considered in this letter can perform guiding, branching, and bending functions of optical waves in the nanometric device.

Atmospheric-pressure low-temperature plasma treatment improves the bonding strength of adhesive resin cement as effectively as alumina sandblasting, and does not alter the zirconia crystal structure.

The feasibility of nanometric practical optical waveguide circuits based on surface plasmon polariton gap waveguides (SPGWs) is investigated in detail through three-dimensional simulations. H-plane planar branching waveguide circuits of subwavelength scale are shown to be possible using SPGWs. The waveguide characteristics of the circuits are found to be highly sensitive to the dimensions of the optical circuit, indicating that highly accurate computer-aided design and simulations are necessary for the construction of practical SPGW-based optical circuits.

We propose two-photon excited fluorescence (TPEF) microscopy employing a novel phase modulation technique of ultra-broadband laser pulses, which allows the relative excitation of an individual fluorophore with respect to other fluorophores. This technique is based on the generation of multi-wavelength pulse train, which independently interacts with each fluorophore. Our technique is applied to dual-color imaging of cells expressing two types of fluorescent proteins. We achieve the selective excitation of one over the other and vice versa. The product of the maximum contrast ratios exceeds 100. We also demonstrate yielded equal excitation rates in the simultaneous excitation. By the selective excitation of a donor fluorescent protein, fluorescence resonance energy transfer imaging is also achieved.

The present study aimed to investigate cellular behavior on nanoscale features of a titanium surface by controlling the deposition time in NaOH. These effects were then evaluated for osteogenic differentiation of rat bone marrow cells to potentially increase the success rate of titanium implants. Titanium disks were left untreated or soaked in 10 M NaOH for 5 min, and 1h, 3h, 9h and 24 h. Scanning electron and probe microscopy were used to evaluate the nanoscale features. Rat bone marrow cells were seeded on the specimens in osteogenic differentiation medium. Alkaline phosphatase activity, osteocalcin production, and mineralization were then analyzed. Statistical significance was analyzed using one-way ANOVA followed by the Tukey test. Nanofeatures were detected at 1 h after NaOH treatment and were well established at 9 h. Alkaline phosphatase activities of specimens soaked for 1 h or 3 h were significantly different from specimens soaked for 9 h or 24 h after 14 days of differentiation. Osteocalcin production and calcium deposition between untreated specimens and specimens soaked for 5 min, as well as between specimens soaked for 9 h and 24 h, were significantly different after 21 days. It was found that the nanoscale modification of a titanium implant surface by NaOH treatment affects osteoblastic differentiation of bone marrow cells and enhances mineralization. This study found that modification of titanium surfaces with NaOH could be an effective method of improving their biological properties. Further developments in nanotechnology may help improve osseointegration of titanium implants.