Spin chiral anisotropy(SChA)refers to the occurrence of different spin polarization in antipodal chiral structures.Herein,we report the SChA in diamagnetic chiral mesostructured In2O3 films(CMIFs)with manifestation of...Spin chiral anisotropy(SChA)refers to the occurrence of different spin polarization in antipodal chiral structures.Herein,we report the SChA in diamagnetic chiral mesostructured In2O3 films(CMIFs)with manifestation of chirality-dependent magnetic circular dichroism(MCD)signals.CMIFs were grown on fluorine-doped tin dioxide conductive glass(FTO)substrates,which were synthesized via a hydrothermal route,with malic acid used as the symmetry-breaking agent.Two levels of chirality have been identified in CMIFs:primary nanoflakes with atomically twisted crystal lattices and secondary helical stacking of the nanoflakes.CMIFs exhibit chirality-dependent asymmetric MCD signals due to the different interactions of chirality-induced effective magnetic field and external magnetic field,which distinguish from the commonly observed external magnetic fielddependent symmetric MCD signals.These findings provide insights into spin manipulation of spin-paired diamagnets.展开更多
In this paper, we are concerned with the existence of a second-order differential equation with m-point boundary conditions on the half line. The existence results are proved by the Leray-Scha¨uder point theorem ...In this paper, we are concerned with the existence of a second-order differential equation with m-point boundary conditions on the half line. The existence results are proved by the Leray-Scha¨uder point theorem in a special Banach space. Green function plays an important role in the proof and its discussion is very interesting. The results obtained generalize those in the previous references.展开更多
目的探讨联苯双酯(DDB)对中波紫外线(UVB)的防护作用及其相关机制研究,为临床应用提供理论依据。方法 DDB和维生素C对照检测五味子甲素衍生物DDB对超氧阴离子(O_2^-)的清除率。MTT法测定DDB、UVB对人永生化角质形成细胞(Ha Ca T)、人真...目的探讨联苯双酯(DDB)对中波紫外线(UVB)的防护作用及其相关机制研究,为临床应用提供理论依据。方法 DDB和维生素C对照检测五味子甲素衍生物DDB对超氧阴离子(O_2^-)的清除率。MTT法测定DDB、UVB对人永生化角质形成细胞(Ha Ca T)、人真皮成纤维细胞(FB)生长的影响及DDB对UVB的防护作用。通过Giemsa染色,从形态学上观察DDB对UVB损伤的防护作用。激光共聚焦观察活性氧簇(ROS)及检测其荧光强度。结果实验结果表明,相同浓度DDB具有强的清除O_2^-的能力;DDB对Ha Ca T、Fb细胞无毒性且可防护UVB损伤。Giemsa染色后,形态学上发现DDB可以明显抑制细胞的凋亡。DDB可抑制Ha Ca T细胞外ROS的生成。结论五味子甲素衍生物DDB对UVB有明显的防护作用,DDB作用机制是通过其抗氧化活性抑制UVB辐射引起的氧化应激及细胞凋亡等,起到紫外线防护作用,有望开发成为有效的抗氧化剂和紫外防护产品。展开更多
基金supported by the National Key Research and Development Program of China(No.2021YFA1200301,S.A.C.)the National Natural Science Foundation of China(Nos.21931008,S.A.C.and 21975184,Y.Y.D.)Shanghai Pilot Program for Basic Research-Shanghai Jiao Tong University(No.21TQ1400219).
文摘Spin chiral anisotropy(SChA)refers to the occurrence of different spin polarization in antipodal chiral structures.Herein,we report the SChA in diamagnetic chiral mesostructured In2O3 films(CMIFs)with manifestation of chirality-dependent magnetic circular dichroism(MCD)signals.CMIFs were grown on fluorine-doped tin dioxide conductive glass(FTO)substrates,which were synthesized via a hydrothermal route,with malic acid used as the symmetry-breaking agent.Two levels of chirality have been identified in CMIFs:primary nanoflakes with atomically twisted crystal lattices and secondary helical stacking of the nanoflakes.CMIFs exhibit chirality-dependent asymmetric MCD signals due to the different interactions of chirality-induced effective magnetic field and external magnetic field,which distinguish from the commonly observed external magnetic fielddependent symmetric MCD signals.These findings provide insights into spin manipulation of spin-paired diamagnets.
基金Supported by the Fundamental Research Funds for the Central Universities (2011YXL044)the NNSF of China (11101385)
文摘In this paper, we are concerned with the existence of a second-order differential equation with m-point boundary conditions on the half line. The existence results are proved by the Leray-Scha¨uder point theorem in a special Banach space. Green function plays an important role in the proof and its discussion is very interesting. The results obtained generalize those in the previous references.
文摘目的探讨联苯双酯(DDB)对中波紫外线(UVB)的防护作用及其相关机制研究,为临床应用提供理论依据。方法 DDB和维生素C对照检测五味子甲素衍生物DDB对超氧阴离子(O_2^-)的清除率。MTT法测定DDB、UVB对人永生化角质形成细胞(Ha Ca T)、人真皮成纤维细胞(FB)生长的影响及DDB对UVB的防护作用。通过Giemsa染色,从形态学上观察DDB对UVB损伤的防护作用。激光共聚焦观察活性氧簇(ROS)及检测其荧光强度。结果实验结果表明,相同浓度DDB具有强的清除O_2^-的能力;DDB对Ha Ca T、Fb细胞无毒性且可防护UVB损伤。Giemsa染色后,形态学上发现DDB可以明显抑制细胞的凋亡。DDB可抑制Ha Ca T细胞外ROS的生成。结论五味子甲素衍生物DDB对UVB有明显的防护作用,DDB作用机制是通过其抗氧化活性抑制UVB辐射引起的氧化应激及细胞凋亡等,起到紫外线防护作用,有望开发成为有效的抗氧化剂和紫外防护产品。
