| 1 | Up-regulation of PIK3CA promotes metastasis in gastric carcinoma显示文摘AIM:To explore expressions of PIK3CA in the progression of gastric cancer from primary to metastasis and its effects on activation of phosphatidylinositol 3-kinase(PI3K)/Akt pathway.METHODS:mRNA and protein levels of PIK3CA were assessed,respectively,by real-time quantitative polymerase chain reaction and immunohistochemistry in specimens of normal gastric mucosa,primary foci and lymph node and distant metastasis of gastric cancer.Akt and phosphorylated Akt protein were also examined by Western blotting in these tissues,in order to analyze the effect of PIK3CA expression level changes on the activation of PI3K/Akt signaling pathway.RESULTS:PIK3CA mRNA in lymph node metastasis were approximately 5 and 2 folds higher,respectively,than that in the corresponding normal gastric mucosa and primary gastric cancer tissues(P<0.05),while no statistical significance was found compared with distant metastasis.Immunohistochemically,PIK3CA protein expression was discovered in 7(35%)specimens of 20 primary foci vs 10(67%)of 15 of lymph node metastasis or 11(61%)of 18 of distant metastasis(35%vs 67%,P=0.015;35%vs 61%,P=0.044).With the increased level of PIK3CA expression,the total Akt protein expression remained almost unchanged,but p-Akt protein was upregulated markedly.CONCLUSION:Increased expression of PIK3CA is expected to be a promising indicator of metastasis in gastric cancer.Up-regulation of PIK3CA may promote the metastasis of gastric cancer through aberrant activation of PI3K/Akt signaling. | Liu JF Zhou XK Chen JH Yi G Chen HG Ba MC Lin SQ Qi YC. | 2010 | World Journal of Gastroenterology2010，16，39： | 20 |
| 2 | INFLUENCE OF EXTRUSION ON DAMPING CAPACITIES OF AS-SPRAY DEPOSITED HIGH SILICON ALLOY ZA27 MODIFIED BY CERIUM显示文摘The effects of cerium modification and extrusion on the resultant damping behavior and mechanical properties of the as-sprayed high silicon alloy ZA27 were investigated in an thort to develop a new functional material possessing high damping capacity and good mechanical properties. The damping capacity, as well as the rslative dynamic modulus, was tneasured at frequencies of 1 and 4 Hertz over the 30 to 200℃runge. At below 80℃ the as-sprayed materials appear to be approximately Asquency independent. Above 80℃, the,naterials becotne temperature sensitive, exhibiting the highest damping for the lowest hequency. The extruded, as-sprayed high silicon alloy ZA27 modified by cerium has the highest damping capacity and elongation values among them. The micro8tructure of the as-sprayed high silicon alloy ZA27 modified by 0. 5 wt% cerium was made up of fine lamellar eutectoid, porositg, a light dot-like phase and a polygonal silicon-rich phase. Finally, the opemtive damping tnechanisms were discussed in light of the data obtained hem characterization of microstructure and damping capacity. The high damping capacity was attributed primarily to phase interface thermoelastic damping between the lamellar phases with various substrvctures,except for the grain refinement. | YC. Liu G.C. Yang YL. Lu and Z.G. Zhu (State Key Lab. of Solidification Processing, Northwestern Polytechnic University, Xi’an 710072, China Laboratory of Internal Friction and Defects in Solids, Chinese Academy of Science, Hefei 230031, China ) | 1997 | Acta Metallurgica Sinica(English Letters)1997，10，5： | 1 |
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