Hydrolysis of organophosphorus by diatom purple acid phosphatase and sequential regulation of cell metabolism.

Phosphorus (P) limitation affects phytoplankton growth and population size in aquatic systems, and consequently limits aquatic primary productivity. Plants have evolved a range of metabolic responses to cope with P limitation, such as accumulation of purple acid phosphatases (PAPs) to enhance acquisition of phosphates. However, it remains unknown whether algae have evolved a similar mechanism.

Design of refractive index sensors based on the wavelength-selective resonant coupling phenomenon in dual-core photonic crystal fibers.

Design strategies for high-sensitivity refractive index sensors based on the principle of wavelength-selective resonant coupling in dual-core photonic crystal fibers are presented. Phase matching at a single wavelength can be achieved between an analyte-filled microstructured core and a small core with a down-doped rod or one small air hole in the center, thus enabling selectively directional resonant-coupling between the two cores. The transmission spectra of the output light presents a notch at the index-matched wavelength, yielding a resonant wavelength depending on the refractive index of the analyte.

Microstructured-core photonic-crystal fiber for ultra-sensitive refractive index sensing.

We propose a novel photonic crystal fiber refractive index sensor which is based on the selectively resonant coupling between a conventional solid core and a microstructured core. The introduced microstructured core is realized by filling the air-holes in the core with low index analyte. We show that a detection limit (DL) of 2.