神经退行性疾病是人类最难治疗的疾病之一.易获取的间充质干细胞(MSCs)可用于自体干细胞移植,间充质干细胞治疗被认为是最有希望的治疗选择之一.然而,传统的生长诱导因子难以实现间充质干细胞的神经分化.电刺激方式可以诱导间充质干细...神经退行性疾病是人类最难治疗的疾病之一.易获取的间充质干细胞(MSCs)可用于自体干细胞移植,间充质干细胞治疗被认为是最有希望的治疗选择之一.然而,传统的生长诱导因子难以实现间充质干细胞的神经分化.电刺激方式可以诱导间充质干细胞的神经分化,但外部电线和复杂的设备给临床治疗带来了很大阻碍.在这项研究中,基于磁电感应效应,我们发现在无需任何生物或化学因子的辅助下,旋转磁场(RMF)驱动下还原氧化石墨烯膜(rGO-M)上产生的无线电信号可以诱导间充质干细胞的神经元样分化.体外实验结果显示,RMF以400 r min^(-1)的速度刺激rGO-M,每天刺激15 min,rGO-M上的MSCs能表达神经元特异性基因和蛋白,连续处理15天后,基因和蛋白的表达量得到明显提升.大鼠体内实验证实,rGO-M上的外源性间充质干细胞可以在旋转磁场的驱动下分化成神经元样细胞.鉴于rGO-M和自体间充质干细胞来源成本较低,rGO-M介导的无线电刺激方法为神经退行性疾病的干细胞治疗提供了一个可行的方案.展开更多
High-k materials as an alternative dielectric layer for SiC power devices have the potential to reduce interfacial state defects and improve MOS channel conduction capability.Besides,under identical conditions of gate...High-k materials as an alternative dielectric layer for SiC power devices have the potential to reduce interfacial state defects and improve MOS channel conduction capability.Besides,under identical conditions of gate oxide thickness and gate voltage,the high-k dielectric enables a greater charge accumulation in the channel region,resulting in a larger number of free electrons available for conduction.However,the lower energy band gap of high-k materials leads to significant leakage currents at the interface with Si C,which greatly affects device reliability.By inserting a layer of SiO_(2)between the high-k material and Si C,the interfacial barrier can be effectively widened and hence the leakage current will be reduced.In this study,the optimal thickness of the intercalated SiO_(2)was determined by investigating and analyzing the gate dielectric breakdown voltage and interfacial defects of a dielectric stack composed of atomic-layer-deposited Al_(2)O_(3)layer and thermally nitride SiO_(2).Current-voltage and high-frequency capacitance-voltage measurements were performed on metal-oxide-semiconductor test structures with 35 nm thick Al_(2)O_(3)stacked on 1 nm,2 nm,3 nm,6 nm,or 9 nm thick nitride SiO_(2).Measurement results indicated that the current conducted through the oxides was affected by the thickness of the nitride oxide and the applied electric field.Finally,a saturation thickness of stacked SiO_(2)that contributed to dielectric breakdown and interfacial band offsets was identified.The findings in this paper provide a guideline for the SiC gate dielectric stack design with the breakdown strength and the interfacial state defects considered.展开更多
基金supported by the National Natural Science Foundation of China(51972148,52272212,and 11904131)Shandong Provincial Natural Science Foundation(ZR2020KE056 and ZR2021YQ04)+1 种基金the Major Scientific and Technological Innovation Project of Shandong Province(2021CXGC010603)the Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong。
文摘神经退行性疾病是人类最难治疗的疾病之一.易获取的间充质干细胞(MSCs)可用于自体干细胞移植,间充质干细胞治疗被认为是最有希望的治疗选择之一.然而,传统的生长诱导因子难以实现间充质干细胞的神经分化.电刺激方式可以诱导间充质干细胞的神经分化,但外部电线和复杂的设备给临床治疗带来了很大阻碍.在这项研究中,基于磁电感应效应,我们发现在无需任何生物或化学因子的辅助下,旋转磁场(RMF)驱动下还原氧化石墨烯膜(rGO-M)上产生的无线电信号可以诱导间充质干细胞的神经元样分化.体外实验结果显示,RMF以400 r min^(-1)的速度刺激rGO-M,每天刺激15 min,rGO-M上的MSCs能表达神经元特异性基因和蛋白,连续处理15天后,基因和蛋白的表达量得到明显提升.大鼠体内实验证实,rGO-M上的外源性间充质干细胞可以在旋转磁场的驱动下分化成神经元样细胞.鉴于rGO-M和自体间充质干细胞来源成本较低,rGO-M介导的无线电刺激方法为神经退行性疾病的干细胞治疗提供了一个可行的方案.
基金Project supported by the Key Area Research and Development Program of Guangdong Province of China(Grant No.2021B0101300005)the National Key Research and Development Program of China(Grant No.2021YFB3401603)。
文摘High-k materials as an alternative dielectric layer for SiC power devices have the potential to reduce interfacial state defects and improve MOS channel conduction capability.Besides,under identical conditions of gate oxide thickness and gate voltage,the high-k dielectric enables a greater charge accumulation in the channel region,resulting in a larger number of free electrons available for conduction.However,the lower energy band gap of high-k materials leads to significant leakage currents at the interface with Si C,which greatly affects device reliability.By inserting a layer of SiO_(2)between the high-k material and Si C,the interfacial barrier can be effectively widened and hence the leakage current will be reduced.In this study,the optimal thickness of the intercalated SiO_(2)was determined by investigating and analyzing the gate dielectric breakdown voltage and interfacial defects of a dielectric stack composed of atomic-layer-deposited Al_(2)O_(3)layer and thermally nitride SiO_(2).Current-voltage and high-frequency capacitance-voltage measurements were performed on metal-oxide-semiconductor test structures with 35 nm thick Al_(2)O_(3)stacked on 1 nm,2 nm,3 nm,6 nm,or 9 nm thick nitride SiO_(2).Measurement results indicated that the current conducted through the oxides was affected by the thickness of the nitride oxide and the applied electric field.Finally,a saturation thickness of stacked SiO_(2)that contributed to dielectric breakdown and interfacial band offsets was identified.The findings in this paper provide a guideline for the SiC gate dielectric stack design with the breakdown strength and the interfacial state defects considered.
