SrTiO3 films with different cation concentration were deposited on Si（001） substrates by oxide molecular beam epitaxy. An amorphous layer was observed at the interface whose thickness depends on the oxygen pressure ...SrTiO3 films with different cation concentration were deposited on Si（001） substrates by oxide molecular beam epitaxy. An amorphous layer was observed at the interface whose thickness depends on the oxygen pressure and the substrate temperature during growth. Although lowering the oxygen vacancy concentration in SrTiO3 led to better insulating performance as indi- cated by the lowered leakage current density of the heterostructure, the dielectric performance was deteriorated because of the thickened interracial layer that dominated the capacitance of SrTiO3/Si heterostructure. Instead of adjusting the oxygen vacan- cy concentration, we propose that controlling the film cation concentration is an effective way to tune the dielectric and insu- lating properties of SrTiO3/Si at the same time.展开更多
文摘为探究猪(Sus scrofa)骨髓间充质干细胞(Bone marrow mesenchymal stem cells,PBMSCs)成软骨分化过程中能量代谢动态变化以及与软骨形成之间的关系,本研究分离并鉴定猪骨髓间充质干细胞,并通过建立诱导分化培养体系获得猪软骨细胞。对PBMSCs成软骨诱导分化第1、6、12和18天的细胞进行软骨形成标记基因、能量代谢相关基因表达模式分析以及能量代谢产物含量检测,且对软骨形成标记基因与能量代谢产物进行相关性分析。结果表明:1)在成软骨分化过程,软骨形成标记基因II型胶原α1链(Collagen type II alpha 1 chain,COL2A1)、SRYbox转录因子9(SRY-box transcription factor 9,SOX9)、聚集蛋白聚糖(Aggrecan,ACAN)、基质金属蛋白酶13(Matrix metallopeptidase 13,MMP13)、RUNX家族转录因子2(RUNX family transcription factor 2,RUNX2)表达水平显著提高(P<0.05);糖酵解限速酶基因己糖激酶1(Hexokinase 1,HK1)、丙酮酸激酶L/R(Pyruvate kinase L/R,PKLR)和乳酸转运关键基因溶质载体家族16成员1(Solute carrier family 16 member 1,SLC16A1)表达水平显著提高(P<0.05),葡萄糖转运关键基因溶质载体家族2成员4(Solute carrier family 2 member 4,SLC2A4)表达水平显著降低(P<0.05);2)随着成软骨分化时间增加,胞内ATP含量和葡萄糖含量显著降低(P<0.05),胞内乳酸、乳酸和葡萄糖比率显著增加(P<0.05)。3)成软骨分化关键基因与能量代谢产物的相关性分析表明,PBMSCs成软骨过程与糖酵解代谢显著相关(P<0.05)。综上,本研究成功建立了一种诱导PBMSCs分化成软骨细胞的方法,并发现在间充质干细胞诱导成软骨细胞过程中,细胞氧化磷酸化水平逐渐降低,糖酵解代谢逐渐增强,为后续深入解析猪体长发育机制提供新视角。
基金supported by the National Basic Research Program of China(Grant No.2012CB921700)the National Natural Science Foundation of China(Grant No.11225422)the US Natural Science Foundation(Grant No.DMR-1106070)
文摘SrTiO3 films with different cation concentration were deposited on Si（001） substrates by oxide molecular beam epitaxy. An amorphous layer was observed at the interface whose thickness depends on the oxygen pressure and the substrate temperature during growth. Although lowering the oxygen vacancy concentration in SrTiO3 led to better insulating performance as indi- cated by the lowered leakage current density of the heterostructure, the dielectric performance was deteriorated because of the thickened interracial layer that dominated the capacitance of SrTiO3/Si heterostructure. Instead of adjusting the oxygen vacan- cy concentration, we propose that controlling the film cation concentration is an effective way to tune the dielectric and insu- lating properties of SrTiO3/Si at the same time.
