Prognostic value of MAGE-A9 expression in patients with colorectal cancer.

MAGE-A9 is a novel member of the melanoma-associated antigen (MAGE) family and is expressed in testicular cancer. The present study investigated MAGE-A9 expression as a potential biomarker in colorectal cancer (CRC). Immunohistochemical analysis was used to determine the expression of MAGE-A9 in 201 cases CRC tissues. We used quantitative real-time polymerase chain reaction (RT-PCR) and western blot analysis to further verify the results. The correlation between MAGE-A9 expression, clinicopathological features and prognosis of CRC patients was analyzed. The results showed that MAGE-A9 was predominantly localized in the cytoplasm of cancer cells and stromal cells. Compared to normal adjacent tissues, the high expression rate of MAGE-A9 in CRC tissues was significantly increased (P<0.001). High MAGE-A9 expression was significantly associated with venous invasion (P=0.008) and lymph node metastasis (P<0.001). The survival rate of the CRC patients who were positive for MAGE-A9 expression was significantly lower than that of CRC patients with negative MAGE-A9 expression. Moreover, univariate and multivariate analyses showed that high MAGE-A9 expression was a poor prognostic factor for CRC patients. Hence, MAGE-A9 is expected to become a new target for CRC treatment.

Two-photon photovoltaic effect in gallium arsenide.

The two-photon photovoltaic effect is demonstrated in gallium arsenide at 976 and 1550 nm wavelengths. A waveguide-photodiode biased in its fourth quadrant harvests electrical power from the optical energy lost to two-photon absorption. The experimental results are in good agreement with simulations based on nonlinear wave propagation in waveguides and the drift-diffusion model of carrier transport in semiconductors. Power efficiency of up to 8% is theoretically predicted in optimized devices.

Low-loss and high index-contrast tantalum pentoxide microring resonators and grating couplers on silicon substrates.

A platform for high index-contrast integrated photonics based on tantalum pentoxide submicrometer waveguides on silicon substrates is introduced. The platform allows demonstration of microring resonators with loaded quality factor, Q, of 67,000 and waveguides with a propagation loss of 4.9 dB/cm. Grating couplers, with an insertion loss of ~6 dB per coupler and 3 dB bandwidth of ~50 nm, are also demonstrated and integrated with microring resonators.

Heterogeneous lithium niobate photonics on silicon substrates.

A platform for the realization of tightly-confined lithium niobate photonic devices and circuits on silicon substrates is reported based on wafer bonding and selective oxidation of refractory metals. The heterogeneous photonic platform is employed to demonstrate high-performance lithium niobate microring optical resonators and Mach-Zehnder optical modulators. A quality factor of ~7.2 × 104 is measured in the microresonators, and a half-wave voltage-length product of 4 V.cm and an extinction ratio of 20 dB is measured in the modulators.

Submicron optical waveguides and microring resonators fabricated by selective oxidation of tantalum.

Submicron tantalum pentoxide ridge and channel optical waveguides and microring resonators are demonstrated on silicon substrates by selective oxidation of the refractory metal, tantalum. The novel method eliminates the surface roughness problem normally introduced during dry etching of waveguide sidewalls and also simplifies fabrication of directional couplers. It is shown that the measured propagation loss is independent of the waveguide structure and thereby limited by the material loss of tantalum pentoxide in waveguides core regions. The achieved microring resonators have cross-sectional dimensions of ~600 nm × ~500 nm, diameters as small as 80 µm with a quality, Q, factor of 4.5 × 10(4), and a finesse of 120.