Ferroelectric SrBi2Ta2O9-(Bi4Ti3)1-xNbxO12 (x = 0.02) (SBT-BTN) multilayer thin films with various stacking periodicity have been synthesized on Ir/Ti/SiO2/Si substrate by metal organic chemical vapor deposition techn...Ferroelectric SrBi2Ta2O9-(Bi4Ti3)1-xNbxO12 (x = 0.02) (SBT-BTN) multilayer thin films with various stacking periodicity have been synthesized on Ir/Ti/SiO2/Si substrate by metal organic chemical vapor deposition technique (MOCVD). Tributylbismuth [Bi(C4H9)3], Strontium-bis[Tantal(pentanethoxy)(2-methoxyethoxid)] [Sr[Ta(OEt)5(OC2H4OMe)]2], Titanium Bis(isopropoxy)bis(1-methoxy-2-methyl-2-propoxide) [Ti(OiPr)2(mmp)2] and Niob-ethoxide [Nb(OC2H5)5] were selected as precursors. X-ray diffraction patterns show that the multilayer films annealed at 800oC consist of fully formed perovskite phase with polycrystalline structure and plate-like grains with no crack. The remanent polarization () and coercive field (Ec) are 16.2 μC/cm2 and 230 kV/cm, respectively, which is much higher, compared to pure SBT film (?= 6.4 μC/cm2, Ec = 154 kV/cm). In the films prepared above 700oC, postannealing increased the capacitor shorting rate;this was attributed to oxidizing of the top iridium layer. In this paper, the dependence of composition variation around stoichiometric on ferroelectric properties in SBT-BTN multilayer films is studied.展开更多
本研究旨在通过生物信息学方法,结合对人体的肿瘤组织切片进行免疫组织化学检测,分析免疫调节分子BTN2A2(butyrophilin subfamily 2 member A2)结构及其在肿瘤组织中的表达,为研究BTN2A2分子的免疫调节功能提供理论和实验支撑。序列分...本研究旨在通过生物信息学方法,结合对人体的肿瘤组织切片进行免疫组织化学检测,分析免疫调节分子BTN2A2(butyrophilin subfamily 2 member A2)结构及其在肿瘤组织中的表达,为研究BTN2A2分子的免疫调节功能提供理论和实验支撑。序列分析表明,BTN2A2具有IgV样结构域,与B7家族分子具有序列同源性和结构相似性。系统发育树分析表明,BTN2A2和已知B7家族分子之间具有亲缘性。通过I-TASSER成功构建BTN2A2蛋白三维晶体结构模型,hBTN2A2配体为Cys,配体结合位点相应氨基酸残基分别为Arg-54、His-56、Ser-111、Val-112和Ala-113。蛋白质-蛋白质相互作用网络(protein-protein interaction,PPI)方法表明,存在10个与BTN2A2相关的分子,其中CD4和CD8与T细胞免疫相关。ZDOCK分析表明,BTN2A2确实可以与T细胞表面CD4和CD8分子结合。ClusterProfiler分析表明,BTN2A2和相关分子主要集中在原发性免疫缺陷、抗原加工和呈递、T细胞受体信号通路等免疫调节方面。流式细胞术(flow cytometry,FCM)分析进一步表明,BTN2A2蛋白与T细胞表面CD4和CD8分子间存在相互作用,且BTN2A2蛋白可抑制CD4^(+)和CD8^(+)T细胞增殖和活化(P<0.001)。免疫组织化学染色显示,hBTN2A2在人肺癌、肝癌、肾癌和食管癌组织中的表达高于正常组织,而在卵巢癌组织未见表达(P<0.05);PrognoScan数据库和Kaplan-Meier曲线进行肺癌患者生存分析表明,hBTN2A2高表达的患者预后良好(P<0.001);TIMER数据库分析表明,肺癌中hBTN2A2表达水平与免疫细胞浸润呈正相关关系;GEPIA数据库分析显示,肺癌中hBTN2A2表达主要与CD8^(+)T细胞、CD3^(+)T细胞、树突状细胞(dendritic cell,DC)、辅助性T细胞(helper T cell,Th)1等免疫细胞浸润有关(P<0.001)。研究结果为免疫调节分子BTN2A2结构和功能性表达的深入研究提供了理论基础。展开更多
文摘Ferroelectric SrBi2Ta2O9-(Bi4Ti3)1-xNbxO12 (x = 0.02) (SBT-BTN) multilayer thin films with various stacking periodicity have been synthesized on Ir/Ti/SiO2/Si substrate by metal organic chemical vapor deposition technique (MOCVD). Tributylbismuth [Bi(C4H9)3], Strontium-bis[Tantal(pentanethoxy)(2-methoxyethoxid)] [Sr[Ta(OEt)5(OC2H4OMe)]2], Titanium Bis(isopropoxy)bis(1-methoxy-2-methyl-2-propoxide) [Ti(OiPr)2(mmp)2] and Niob-ethoxide [Nb(OC2H5)5] were selected as precursors. X-ray diffraction patterns show that the multilayer films annealed at 800oC consist of fully formed perovskite phase with polycrystalline structure and plate-like grains with no crack. The remanent polarization () and coercive field (Ec) are 16.2 μC/cm2 and 230 kV/cm, respectively, which is much higher, compared to pure SBT film (?= 6.4 μC/cm2, Ec = 154 kV/cm). In the films prepared above 700oC, postannealing increased the capacitor shorting rate;this was attributed to oxidizing of the top iridium layer. In this paper, the dependence of composition variation around stoichiometric on ferroelectric properties in SBT-BTN multilayer films is studied.
文摘本研究旨在通过生物信息学方法,结合对人体的肿瘤组织切片进行免疫组织化学检测,分析免疫调节分子BTN2A2(butyrophilin subfamily 2 member A2)结构及其在肿瘤组织中的表达,为研究BTN2A2分子的免疫调节功能提供理论和实验支撑。序列分析表明,BTN2A2具有IgV样结构域,与B7家族分子具有序列同源性和结构相似性。系统发育树分析表明,BTN2A2和已知B7家族分子之间具有亲缘性。通过I-TASSER成功构建BTN2A2蛋白三维晶体结构模型,hBTN2A2配体为Cys,配体结合位点相应氨基酸残基分别为Arg-54、His-56、Ser-111、Val-112和Ala-113。蛋白质-蛋白质相互作用网络(protein-protein interaction,PPI)方法表明,存在10个与BTN2A2相关的分子,其中CD4和CD8与T细胞免疫相关。ZDOCK分析表明,BTN2A2确实可以与T细胞表面CD4和CD8分子结合。ClusterProfiler分析表明,BTN2A2和相关分子主要集中在原发性免疫缺陷、抗原加工和呈递、T细胞受体信号通路等免疫调节方面。流式细胞术(flow cytometry,FCM)分析进一步表明,BTN2A2蛋白与T细胞表面CD4和CD8分子间存在相互作用,且BTN2A2蛋白可抑制CD4^(+)和CD8^(+)T细胞增殖和活化(P<0.001)。免疫组织化学染色显示,hBTN2A2在人肺癌、肝癌、肾癌和食管癌组织中的表达高于正常组织,而在卵巢癌组织未见表达(P<0.05);PrognoScan数据库和Kaplan-Meier曲线进行肺癌患者生存分析表明,hBTN2A2高表达的患者预后良好(P<0.001);TIMER数据库分析表明,肺癌中hBTN2A2表达水平与免疫细胞浸润呈正相关关系;GEPIA数据库分析显示,肺癌中hBTN2A2表达主要与CD8^(+)T细胞、CD3^(+)T细胞、树突状细胞(dendritic cell,DC)、辅助性T细胞(helper T cell,Th)1等免疫细胞浸润有关(P<0.001)。研究结果为免疫调节分子BTN2A2结构和功能性表达的深入研究提供了理论基础。
