| 21. |
- Zhang, Xiaoying, et al.
(författare)
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Liver X receptor agonist downregulates hepatic apoM expression in vivo and in vitro
- 2008
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Ingår i: Biochemical and Biophysical Research Communications. - : Elsevier BV. - 1090-2104 .- 0006-291X. ; 371:1, s. 114-117
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Tidskriftsartikel (refereegranskat)abstract
- It has been demonstrated that apolipoprotein M (apoM), a recently discovered HDL apolipoprotein, has antiatherosclerotic properties, which may be mediated by the enhancement of reversed cholesterol transportation and/or hepatic cholesterol catabolism. The detailed mechanisms are unknown yet. Liver X receptor (LXR) belongs to the nuclear receptor superfamily and is a ligand-activated transcription factor involved in the regulation of lipid metabolism and inflammation. Activation of LXR in the cell cultures results in an enhancement of cholesterol efflux to apoAl. In the present study, we investigated effects of the LXR agonist, T0901317 on hepatic apoM expression in vivo and in vitro. Serum apoM levels in mice given T0901317 at 10 mg or 100 mg/kg for 7 days were reduced by 12-17% (P < 0.05). In HepG2 cell cultures, apoM mRNA levels were significantly lower in presence of 25 mu M T0901317 (37.1%) than in control cells (P < 0.001). A similar reduction was found by the addition of 9-cis retinoic acid (RA). Twenty-five micromolar T0901317 together with 100 nM RA decreased apoM mRNA expression by 65% (P < 0.001). Thus, the LXR agonist T0901317 significantly downregulates apoM mRNA expression in vivo and in vitro, which indicates that apoM is another novel target gene regulated by the LXR. The combination of RA and T0901317 showed additive effects, which suggests that apoM expression can be modulated by LXR/RXR pathway.
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| 22. |
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| 23. |
- Zhu, Ning, et al.
(författare)
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A hybrid modeling for the theoretical analysis of reflections in a multimode-interference coupler based on silicon-on-insulator nanowires
- 2008
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Ingår i: Optics Communications. - : Elsevier BV. - 0030-4018 .- 1873-0310. ; 281:11, s. 3099-3104
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Tidskriftsartikel (refereegranskat)abstract
- A hybrid method combining the three-dimensional (3D) beam propagation method (BPM) and a 3D finite-difference time-domain (FDTD) method is presented for the simulation of multimode-interference (MMI) couplers based on silicon-on-insulator (SOI) nanowires. This hybrid method makes it possible to have a robust analysis for the reflection properties while avoiding a time-consumed computation with a simplex 3D-FDTD simulation. The reflected power is sensitive to both the length and the width of the MMI coupler and thus one should choose the optimal values for good self-imaging. Furthermore, the reflection could be reduced by introducing tapers between the MMI section and the access waveguides.
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| 24. |
- Zhu, Ning, et al.
(författare)
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Bragg grating-assisted optical triplexer using two silicon nanowire-based directional couplers
- 2009
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Ingår i: 2009 Asia Communications and Photonics Conference and Exhibition, ACP 2009. - Washington, D.C. : OSA. - 9781557528773 ; , s. 5377094-
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Konferensbidrag (refereegranskat)abstract
- A triplexer based on silicon nanophotonic wire structure consisting of two Bragg grating-assisted directional couplers is proposed. The device has low loss, low crosstalk, and a footprint of only 210 x40 μm, The 1-dB bandwidth for the three channels located at 1310, 1490 and 1550 nm are 110, 20, and 20 nm, respectively.
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| 25. |
- Zhu, Ning, et al.
(författare)
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Cross-Order Echelle Grating Triplexer Based on Amorphous Silicon Nanowire Platform
- 2008
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Ingår i: 2008 7TH INTERNATIONAL CONFERENCE ON THE OPTICAL INTERNET (COIN). - NEW YORK : IEEE. - 9784885522307 ; , s. 37-38
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Konferensbidrag (refereegranskat)abstract
- We present fabrication and measurement results of an ultracompact silicon-on-insulator-based echelle-grating triplexer, which uses different diffraction orders to cover a large spectral range from 1.3 mu m to 1.5 mu m, with a footprint of 150 mu m x 200 mu m.
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| 26. |
- Zhu, Ning, 1979-
(författare)
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Design, Fabrication and Characterization of Planar Lightwave Circuits Based on Silicon Nanowire Platform
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Optical devices based on Planar Lightwave Circuit (PLC) technology have well been studied due to their inherited advantages from Integrated Circuits (IC), such as: small size, high reliability, mass production and potential integration with microelectronics. Among all the materials, silicon nanowire platform gains more and more interest. The large refractive index difference between core and cladding allows tremendous reduction of the component size. This thesis studies theoretically and experimentally some integrated optical devices based on silicon nanophotonic platform, including echelle grating demultiplexers and photonic crystals. Some of the numerical methods are introduced first. Scalar integral diffraction method is efficient for calculating the diffraction efficiency of gratings. Beam propagation method and finite-difference time-domain method are also introduced, for simulating the light propagation along the devices. The fabrication technology and characterization methods are described. The fabrication steps involve: plasma assisted film deposition, E-beam lithography, RIE-etching. All these steps are proceeded under cleanroom environment. The characterization is mainly based on two methods: end-fire coupling and vertical grating coupling. The grating coupler is more efficient compared with the butt-coupling between fiber and nanowires, but is worse solution for final packaging. Two types of components have been realized and characterized with the above technology. The echelle grating demultiplexer is one of the key components in WDM networks. A method for increasing the diffraction efficiency based on total internal reflection is applied, and a significant improvement of the diffraction efficiency of more than 3dB is achieved. A novel cross-order echelle grating-based triplexer, a bidirectional transceiver for application in the Passive Optical Networks (PON), has been designed and fabricated, which can multi/demultiplex three channels located at 1310nm, 1490nm and 1550nm. Polarization dependence issue of echelle grating demultiplexers has been studied. Two polarization compensation schemes have been proposed, which are for the first time polarization insensitive designs of echelle grating demultiplexers based on silicon nanowire platform. Photonic crystal devices are also addressed in the thesis. There has been little research on the photonic crystal cavity based on pillar type. A silicon pillar type photonic crystal cavity has been fabricated with the measured Q value as high as about 104, and with an extremely high sensitivity for the changing of the background material or the effective diameter of the pillars. This kind of structure has the advantage on sensing applications compared to the air-hole type structure.
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| 27. |
- Zhu, Ning, et al.
(författare)
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Design of a polarization-insensitive echelle grating demultiplexer based on silicon nanophotonic wires
- 2008
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Ingår i: IEEE Photonics Technology Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 1041-1135 .- 1941-0174. ; 20:9-12, s. 860-862
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Tidskriftsartikel (refereegranskat)abstract
- A polarization-insensitive design of an echelle grating (or etched diffraction grating) demultiplexer based on silicon nanowires is proposed in the present letter, by introducing a polarization compensation area in its free propagation region. The polarization-dependent wavelength shift of the present device has been compensated at the whole spectral range. For a design with nine channels and 10-nm channel spacing, when the wavelength shift at the central channel 1550 nm is. completely compensated, the wavelength shifts of the two edge channels are only 0.14 and 0.15 nm, which are acceptable.
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| 28. |
- Zhu, Ning, et al.
(författare)
-
Etched diffraction grating demultiplexers based on amorphous silicon nanowire platform
- 2008
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Ingår i: 2008 Asia Optical Fiber Communication and Optoelectronic Exposition and Conference, AOE 2008. - 9781557528636
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Konferensbidrag (refereegranskat)abstract
- We present some theoretical and experimental results of Etched Diffraction Grating demultiplexer based on amorphous silicon nanowire platform, including issues with polarization sensitivity, diffraction efficiency and an application to triplexer.
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| 29. |
- Zhu, Ning, et al.
(författare)
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Experimental demonstration of a cross-order echelle grating triplexer based on an amorphous silicon nanowire platform
- 2009
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Ingår i: Optics Letters. - 0146-9592 .- 1539-4794. ; 34:3, s. 383-385
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Tidskriftsartikel (refereegranskat)abstract
- We present the design, fabrication, and characterization of an ultracompact silicon-on-insulator-based echelle grating triplexer. It is based on the cross-order design, which utilizes different diffraction orders to cover a large spectral range from 1.3 to 1.5 mu m with three channels located at 1310, 1490, and 1550 nm and with a footprint of 150 mu m X 130 mu m.
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| 30. |
- Zhu, Ning, et al.
(författare)
-
Total internal reflection type echelle grating demultiplexer based on amorphous silicon nanowire platform
- 2008
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - Hangzhou : SPIE.
-
Konferensbidrag (refereegranskat)abstract
- In this paper we present measurement results of an ultracompact echelle-grating demultiplexer based on silicon-on-insulator nanowire platform, in which we introduced a total internal reflection design of the grating facets to improve the diffraction efficiency. An average increase of the diffraction efficiency with 3.7dB is observed for the 3 channels compared to a normal design.
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