16 research outputs found
Regulating inflammation through the anti-inflammatory enzyme platelet-activating factor-acetylhydrolase
Platelet-activating factor (PAF) is one of the most potent lipid mediators involved in inflammatory events. The acetyl group at the sn-2 position of its glycerol backbone is essential for its biological activity. Deacetylation induces the formation of the inactive metabolite lyso-PAF. This deacetylation reaction is catalyzed by PAF-acetylhydrolase (PAF-AH), a calcium independent phospholipase A2 that also degrades a family of PAF-like oxidized phospholipids with short sn-2 residues. Biochemical and enzymological evaluations revealed that at least three types of PAF-AH exist in mammals, namely the intracellular types I and II and a plasma type. Many observations indicate that plasma PAF AH terminates signals by PAF and oxidized PAF-like lipids and thereby regulates inflammatory responses. In this review, we will focus on the potential of PAF-AH as a modulator of diseases of dysregulated inflammation
Low-loss phased-array based 4-channel wavelength demultiplexer integrated with photodetectors
\u3cp\u3eA 4-channel phased-array wavelength division demultiplexer with 1.8 nm channel spacing at 1.54μm has been monolithically integrated with photodetectors in InP/InGaAsP. On chip losses are 3.5 to 4.5 dB. These are the lowest losses reported so far for demultiplexers monolithically integrated with photodetectors. Nearest neighbor crosstalk ranges from -12 to -21 dB.\u3c/p\u3
Novel InP-based phased-array wavelength demultiplexer using a generalized MMI-MZI configuration
A novel type of wavelength demultiplexer is presented based on a generalized multimode interference/Mach Zehnder interferometer (MMI-MZI) configuration. This device combines the potential of low loss and high uniformity of the output channels with a small device size. Feasibility of the novel concept is demonstrated experimentally for a 4-channel demultiplexer with 4 nm channel spacing. Dimensions are 2800*106 mu m, which is the smallest device size reported so fa