In order to meet the requirements of nondestructive testing of true 3D topography of micro-nano structures,a novel three-dimensional atomic force microscope(3D-AFM)based on flared tip is developed.A high-precision sca...In order to meet the requirements of nondestructive testing of true 3D topography of micro-nano structures,a novel three-dimensional atomic force microscope(3D-AFM)based on flared tip is developed.A high-precision scanning platform is designed to achieve fast servo through moving probe and sample simultaneously,and several combined nanopositioning stages are used to guarantee linearity and orthogonality of displacement.To eliminate the signal deviation caused by AFM-head movement,a traceable optical lever system is designed for cantilever deformation detection.In addition,a method of tailoring the cantilever of commercial probe with flared tip is proposed to reduce the lateral force applied on the tip in measurement.The tailored probe is mounted on the 3D-AFM,and 3D imaging experiments are conducted on different samples by use of adaptive-angle scanning strategy.The results show the roob-mean-square value of the vertical displacement noise(RMS)of the prototype is less than 0.1 nm and the high/width measurement repeatability(peak-to-peak)is less than 2.5 nm.展开更多
Objective： The aim of this study was to investigate the characteristics of gene changes from Barrett＇s esophagus （BE） to esophageal adenocarcinoma by cDNA microarray. Methods： The cDNA retro-transcribed from equa...Objective： The aim of this study was to investigate the characteristics of gene changes from Barrett＇s esophagus （BE） to esophageal adenocarcinoma by cDNA microarray. Methods： The cDNA retro-transcribed from equal quantity mRNA from esophageal carcinoma and BE tissues as well as control normal epithelium of esophagus which were from one patient with esophageal adenocarcinoma were labeled with Cy5 and Cy3 fluorescence as probes. The mixed probes were hybridized with two pieces gene chip respectively. It was scanned by laser scanner Scan Array 4000. The acquired images were analyzed by software GenePix Pro 3.0. Results： A total of 214 genes were screened out which expression levels were more than 2 times in hybridization of esophageal adenocarcinoma vs normal epithelium of esophagus, whereas 90 genes in hybridization of BE vs normal epithelium. A parallel comparison among these two gene profiles showed that a total of 45 genes with 24 downregulation and 21 up-regulation which expression levels were more than 2 times between the BE and the esophageal adenocarcinoma. Among these, there were 27 genes with 18 downregulafion and 9 up-regulation which implicated the tendencies progressing from BE to esophageal adenocarcinoma. Conclusion： These genes or their products which implicate the tendencies can be chosen as indicators of carcinogenesis with high risk index for BE.展开更多
基金National Key Research and Development Pragram of China(No.2016YFF0200602)National Natural Science Foundation of China(No.61973233)。
文摘In order to meet the requirements of nondestructive testing of true 3D topography of micro-nano structures,a novel three-dimensional atomic force microscope(3D-AFM)based on flared tip is developed.A high-precision scanning platform is designed to achieve fast servo through moving probe and sample simultaneously,and several combined nanopositioning stages are used to guarantee linearity and orthogonality of displacement.To eliminate the signal deviation caused by AFM-head movement,a traceable optical lever system is designed for cantilever deformation detection.In addition,a method of tailoring the cantilever of commercial probe with flared tip is proposed to reduce the lateral force applied on the tip in measurement.The tailored probe is mounted on the 3D-AFM,and 3D imaging experiments are conducted on different samples by use of adaptive-angle scanning strategy.The results show the roob-mean-square value of the vertical displacement noise(RMS)of the prototype is less than 0.1 nm and the high/width measurement repeatability(peak-to-peak)is less than 2.5 nm.
文摘Objective： The aim of this study was to investigate the characteristics of gene changes from Barrett＇s esophagus （BE） to esophageal adenocarcinoma by cDNA microarray. Methods： The cDNA retro-transcribed from equal quantity mRNA from esophageal carcinoma and BE tissues as well as control normal epithelium of esophagus which were from one patient with esophageal adenocarcinoma were labeled with Cy5 and Cy3 fluorescence as probes. The mixed probes were hybridized with two pieces gene chip respectively. It was scanned by laser scanner Scan Array 4000. The acquired images were analyzed by software GenePix Pro 3.0. Results： A total of 214 genes were screened out which expression levels were more than 2 times in hybridization of esophageal adenocarcinoma vs normal epithelium of esophagus, whereas 90 genes in hybridization of BE vs normal epithelium. A parallel comparison among these two gene profiles showed that a total of 45 genes with 24 downregulation and 21 up-regulation which expression levels were more than 2 times between the BE and the esophageal adenocarcinoma. Among these, there were 27 genes with 18 downregulafion and 9 up-regulation which implicated the tendencies progressing from BE to esophageal adenocarcinoma. Conclusion： These genes or their products which implicate the tendencies can be chosen as indicators of carcinogenesis with high risk index for BE.
