目的:探究正常肺组织、肺腺癌癌旁和肺腺癌中所有基因的表达水平趋势,寻找特征性基因并进行实验验证。方法:下载加州大学圣克鲁斯分校(University of California,Santa Cruz,UCSC)数据中心中癌症基因组图谱(the cancer genome atlas,TC...目的:探究正常肺组织、肺腺癌癌旁和肺腺癌中所有基因的表达水平趋势,寻找特征性基因并进行实验验证。方法:下载加州大学圣克鲁斯分校(University of California,Santa Cruz,UCSC)数据中心中癌症基因组图谱(the cancer genome atlas,TCGA)和基因型-组织表达项目(genotype-tissue expression,GTEX)的整合数据,采用R语言分析所有基因的表达趋势,寻找特征性基因,提取癌旁和肿瘤组织共同高表达的基因集,进行GO和KEGG分析富集情况,鉴定最显著的通路中在肺组织和癌旁及肺腺癌中变化最大的基因。通过细胞生物学实验验证候选基因在肿瘤中的作用。结果:整合数据显示存在一群正常组织中低表达但在肺腺癌癌旁和肺腺癌中高表达的基因(DEGS2、PIGY、FUCA、GM2A),GO分析显示该基因群富集最显著的通路是膜脂质代谢过程,对该通路基因和符合趋势的基因取交集,发现DEGS2在癌旁和癌组织中升高最明显,升高倍数达3.27倍。实验证实,敲除DEGS224 h后细胞迁移能力下降,72 h后细胞活性下降55.0%。结论:DEGS2在癌旁和肺腺癌中呈高表达,其表达能促进肺腺癌的增殖和迁移,从而进一步驱动从癌旁组织到癌的发展。展开更多
A Si doped AlGaN/GaN HEMT structure with high Al content (x=43%) in the barrier layer is grown on sapphire substrate by RF-MBE.The structural and electrical properties of the heterostructure are investigated by the tr...A Si doped AlGaN/GaN HEMT structure with high Al content (x=43%) in the barrier layer is grown on sapphire substrate by RF-MBE.The structural and electrical properties of the heterostructure are investigated by the triple axis X-ray diffraction and Van der Pauw-Hall measurement,respectively.The observed prominent Bragg peaks of the GaN and AlGaN and the Hall results show that the structure is of high quality with smooth interface.The high 2DEG mobility in excess of 1260cm2/(V·s) is achieved with an electron density of 1.429×10 13cm -2 at 297K,corresponding to a sheet-density-mobility product of 1.8×10 16V -1·s -1.Devices based on the structure are fabricated and characterized.Better DC characteristics,maximum drain current of 1.0A/mm and extrinsic transconductance of 218mS/mm are obtained when compared with HEMTs fabricated using structures with lower Al mole fraction in the AlGaN barrier layer.The results suggest that the high Al content in the AlGaN barrier layer is promising in improving material electrical properties and device performance.展开更多
The spin-dependent conductance and magnetoresistance ratio （MRR） for a semiconductor heterostructures consisting of two magnetic barriers with different height and space have been investigated by the transfer-matrix...The spin-dependent conductance and magnetoresistance ratio （MRR） for a semiconductor heterostructures consisting of two magnetic barriers with different height and space have been investigated by the transfer-matrix method. It is shown that the splitting of the conductance for parallel and antiparallel magnetization configurations results in tremendous spin-dependent MRR, and the maximal MRRs reach 5300% and 3800% for the magnetic barrier spaces W = 81.3 and 243.9 nm, respectively. The obtained spin-filtering transport property of nanostructures with magnetic barriers may be useful to magnetic-barrier-based spintronics.展开更多
In this paper, we obtain considerable spin-orbit （SO） parameters in AlxGa1-xN/GaN quantum wells （QWs） with sheet carrier concentration N8 = 120 × 10^11/cm^2. With increasing AI content （x） of the barrier, t...In this paper, we obtain considerable spin-orbit （SO） parameters in AlxGa1-xN/GaN quantum wells （QWs） with sheet carrier concentration N8 = 120 × 10^11/cm^2. With increasing AI content （x） of the barrier, the SO parameters increase as a whole, and the two major contributions are found to be the decrease of the expansion region of the envelope functions and the increase of the polarized electric field in the well. Compared with the Rashba parameters for the first two subbands, the intersubband SO parameter is a bit smaller and varies more slowly with x. The results indicate the SO parameters, especially the Rashba parameters can be engineered by the AI composition of the barrier, which may be helpful to the spin manipulation of III-nitride low-dimensional heterostructures.展开更多
文摘目的:探究正常肺组织、肺腺癌癌旁和肺腺癌中所有基因的表达水平趋势,寻找特征性基因并进行实验验证。方法:下载加州大学圣克鲁斯分校(University of California,Santa Cruz,UCSC)数据中心中癌症基因组图谱(the cancer genome atlas,TCGA)和基因型-组织表达项目(genotype-tissue expression,GTEX)的整合数据,采用R语言分析所有基因的表达趋势,寻找特征性基因,提取癌旁和肿瘤组织共同高表达的基因集,进行GO和KEGG分析富集情况,鉴定最显著的通路中在肺组织和癌旁及肺腺癌中变化最大的基因。通过细胞生物学实验验证候选基因在肿瘤中的作用。结果:整合数据显示存在一群正常组织中低表达但在肺腺癌癌旁和肺腺癌中高表达的基因(DEGS2、PIGY、FUCA、GM2A),GO分析显示该基因群富集最显著的通路是膜脂质代谢过程,对该通路基因和符合趋势的基因取交集,发现DEGS2在癌旁和癌组织中升高最明显,升高倍数达3.27倍。实验证实,敲除DEGS224 h后细胞迁移能力下降,72 h后细胞活性下降55.0%。结论:DEGS2在癌旁和肺腺癌中呈高表达,其表达能促进肺腺癌的增殖和迁移,从而进一步驱动从癌旁组织到癌的发展。
文摘A Si doped AlGaN/GaN HEMT structure with high Al content (x=43%) in the barrier layer is grown on sapphire substrate by RF-MBE.The structural and electrical properties of the heterostructure are investigated by the triple axis X-ray diffraction and Van der Pauw-Hall measurement,respectively.The observed prominent Bragg peaks of the GaN and AlGaN and the Hall results show that the structure is of high quality with smooth interface.The high 2DEG mobility in excess of 1260cm2/(V·s) is achieved with an electron density of 1.429×10 13cm -2 at 297K,corresponding to a sheet-density-mobility product of 1.8×10 16V -1·s -1.Devices based on the structure are fabricated and characterized.Better DC characteristics,maximum drain current of 1.0A/mm and extrinsic transconductance of 218mS/mm are obtained when compared with HEMTs fabricated using structures with lower Al mole fraction in the AlGaN barrier layer.The results suggest that the high Al content in the AlGaN barrier layer is promising in improving material electrical properties and device performance.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10574042 and 10974052)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20060542002)
文摘The spin-dependent conductance and magnetoresistance ratio （MRR） for a semiconductor heterostructures consisting of two magnetic barriers with different height and space have been investigated by the transfer-matrix method. It is shown that the splitting of the conductance for parallel and antiparallel magnetization configurations results in tremendous spin-dependent MRR, and the maximal MRRs reach 5300% and 3800% for the magnetic barrier spaces W = 81.3 and 243.9 nm, respectively. The obtained spin-filtering transport property of nanostructures with magnetic barriers may be useful to magnetic-barrier-based spintronics.
文摘In this paper, we obtain considerable spin-orbit （SO） parameters in AlxGa1-xN/GaN quantum wells （QWs） with sheet carrier concentration N8 = 120 × 10^11/cm^2. With increasing AI content （x） of the barrier, the SO parameters increase as a whole, and the two major contributions are found to be the decrease of the expansion region of the envelope functions and the increase of the polarized electric field in the well. Compared with the Rashba parameters for the first two subbands, the intersubband SO parameter is a bit smaller and varies more slowly with x. The results indicate the SO parameters, especially the Rashba parameters can be engineered by the AI composition of the barrier, which may be helpful to the spin manipulation of III-nitride low-dimensional heterostructures.
