A new material platform of Si photonics for implementing architecture of dense wavelength division multiplexing on Si bulk wafer.

A new materials group to implement dense wavelength division multiplexing (DWDM) in Si photonics is proposed. A large thermo-optic (TO) coefficient of Si malfunctions multiplexer/demultiplexer (MUX/DEMUX) on a chip under thermal fluctuation, and thus DWDM implementation, has been one of the most challenging targets in Si photonics. The present study specifies an optical materials group for DWDM by a systematic survey of their TO coefficients and refractive indices. The group is classified as mid-index contrast optics (MiDex) materials, and non-stoichiometric silicon nitride (SiNx) is chosen to demonstrate its significant thermal stability. The TO coefficient of non-stoichiometric SiNx is precisely measured in the temperature range 24-76 °C using the SiNx rings prepared by two methods: chemical vapor deposition (CVD) and physical vapor deposition (PVD). The CVD-SiNx ring reveals nearly the same TO coefficient reported for stoichiometric CVD-Si3N4, while the value for the PVD-SiNx ring is slightly higher. Both SiNx rings lock their resonance frequencies within 100 GHz in this temperature range. Since CVD-SiNx needs a high temperature annealing to reduce N-H bond absorption, it is concluded that PVD-SiNx is suited as a MiDex material introduced in the CMOS back-end-of-line. Further stabilization is required, considering the crosstalk between two channels; a 'silicone' polymer is employed to compensate for the temperature fluctuation using its negative TO coefficient, called athermalization. This demonstrates that the resonance of these SiNx rings is locked within 50 GHz at the same temperature range in the wavelength range 1460-1620 nm (the so-called S, C, and L bands in optical fiber communication networks). A further survey on the MiDex materials strongly suggests that Al2O3, Ga2O3 Ta2O5, HfO2 and their alloys should provide even more stable platforms for DWDM implementation in MiDex photonics. It is discussed that the MiDex photonics will find various applications such as medical and environmental sensing and in-vehicle data-communication.

Effect of weikangning on growth and cell cycle regulators of gastric cancer cell / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To study the effect of Weikangning (WKN) containing serum on growth and cell cycle regulators of gastric cancer cell.</p><p><b>METHODS</b>WKN containing drug serum was prepared by gastric perfusion of WKN in different dosages to SD rats. Gastric cancer cells were cultured in medium contained the drug serum with different concentrations of WKN. The change of cell cycle was detected by flow cytometry, and the mRNA and protein expressions of CyclinD2, CyclinE, Cyclin-dependant kinase2 (CdK2), Cdk4, Cdk6 and p16(INK4a), p27(KIP1) were detected with immunohistochemistry (IHC) SABC method and RT-PCR.</p><p><b>RESULTS</b>After WKN intervention, the cancer cells were constrained in stage G0/G1, unable or retardatory to enter stage G (namely, the DNA synthesis stage). IHC examination showed the grey scale values of CyclinD2, CyclinE, Cdk2, Cdk4 and Cdk6 were higher, and that of p27(KIP1) and p16(INK4a) were lower in cells after moderate/high dosage WKN intervention than those in the blank control (P < 0.01); RT-PCR showed the OPTD values of CyclinD2, CyclinE, Cdk2, Cdk4 and Cdk6 were lower, and that of p27(KIP1) and p16(INK4a) were higher in cells after moderate/high dosage WKN intervention than those in the blank control (P < 0.01).</p><p><b>CONCLUSION</b>WKN can inhibit the expressions of cell cycle promoting related factors of gastric cancer cell, including CyclinD2, CyclinE, Cdk2, Cdk4 and Cdk6, also enhance the expressions of cell cycle inhibiting factors of gastric cancer cell, as p27(KIP1) and p16(INK4a), which may be the mechanism of action of the remedy in preventing the growth of gastric cancer cells.</p>

Effects of weikangning contained serum on growth of gastric cancer cell, expression of vascular endothelial growth factor and its receptors including KDR and fit-1 / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe the effect of drug-containing serum of Chinese traditional herbal decoction Weikangning (WKN) on growth of gastric cancer cell, expression of vascular endothelial growth factor (VEGF) and its receptors including KDR and Flt-1.</p><p><b>METHODS</b>A total of 120 male Wistar rats were given high, medium and low-dose WKN. After the drug-containing serum was prepared, the gastric cancer cells MGC-803 of different dose groups were cultured with the drug-containing serum, respectively. The gastric cell growth was observed by using light microscope and flow cytometer,the expression of VEGF and its receptor Flt-1 was detected with SABC immunohistochemistry method and the mRNA expression levels of VEGF and its receptors including KDR and Flt-1 of different groups were detected with reverse transcription-polymerase chain reaction (RT-PCR), respectively.</p><p><b>RESULTS</b>The gastric cancer cell growth and cell cycle of the three medicated groups were significantly improved as compared with those of the control group (P <0. 01) ,the proportion of cells in G0 - G1 phase was increased,while the cells in S phase were decreased. It was shown that the apoptotic rates were increased in the medicated groups in a dose-dependent manner. The gray scales ( microm(2) ) of VEGF and Flt-1 in high, medium and low dose groups was 182. 44 +/-0. 54,178. 65 +/-0. 56,174. 80 +/-0. 81 and 168. 51 +/- 0. 81,162. 01 +/-0. 52,148. 20 +/-0. 69, respectively vs 147.82 +/-0. 15(P <0.01) and 144.31 +/-0.71 (P <0.01) in the control group. The mRNA expression of VEGF and its receptors significantly decreased in gastric cancer cells after cultured with WKN contained serum (P < 0. 01 ).</p><p><b>CONCLUSION</b>WKN has inhibitory effects on gastric cancer cell growth and mRNA expression of VEGF as well as its receptors KDR and Flt-1.</p>