37 research outputs found
Magnetic and Electrical Properties of Heusler Alloy Co 2 MnSi Thin Films Grown on Ge(001) Substrates via an Al 2 O 3 Tunnel Barrier
Heusler alloy Co 2 MnSi/Al 2 O 3 heterostructures on single-crystal Ge(001) substrates were prepared through magnetron sputtering for both Co 2 MnSi and Al 2 O 3 thin films as a promising candidate for future-generation semiconductor-based spintronic devices. Sufficiently high saturation magnetization 781 emu/cm 3 was obtained for the Co 2 MnSi thin film. Furthermore, the current versus voltage (I-V) characteristics showed that the tunneling conduction was dominant in Co 2 MnSi/Al 2 O 3 (2 nm)/Ge(001) heterostructure and the I-V characteristics were slightly dependent on temperature. The conductance versus voltage (dI/dV-V) characteristics indicated that the potential barrier height at the Co 2 MnSi/Al 2 O 3 interface was almost equal to that at the n-Ge/Al 2 O 3 interface for the prepared Co 2 MnSi/Al 2 O 3 /Ge(001) heterostructure
Magnetic and Electrical Properties of Heusler Alloy Co 2
Heusler alloy Co2MnSi/Al2O3 heterostructures on single-crystal Ge(001) substrates were prepared through magnetron sputtering for both Co2MnSi and Al2O3 thin films as a promising candidate for future-generation semiconductor-based spintronic devices. Sufficiently high saturation magnetization 781 emu/cm3 was obtained for the Co2MnSi thin film. Furthermore, the current versus voltage (I-V) characteristics showed that the tunneling conduction was dominant in Co2MnSi/Al2O3 (2 nm)/Ge(001) heterostructure and the I-V characteristics were slightly dependent on temperature. The conductance versus voltage (dI/dV-V) characteristics indicated that the potential barrier height at the Co2MnSi/Al2O3 interface was almost equal to that at the n-Ge/Al2O3 interface for the prepared Co2MnSi/Al2O3/Ge(001) heterostructure
Safflower Yellow B Protects Brain against Cerebral Ischemia Reperfusion Injury through AMPK/NF-kB Pathway
Inflammation had showed its important role in the pathogenesis of cerebral ischemia and secondary damage. Safflower yellow B (SYB) had neuroprotective effects against oxidative stress-induced brain injuries, but the mechanisms were still largely unknown to us. In this study, we tried to investigate the anti-inflammation effects of SYB and the possible roles of AMPK/NF-κB signaling pathway on these protective effects. In vivo, brain ischemia/reperfusion (I/R) was induced by transient middle cerebral artery occlusion for 2 h and reperfusion for 20 h. Neurofunctional evaluation, infarction area, and brain water contents were measured. Brain injury markers and inflammatory cytokines levels were measured by ELISA kits. In vitro, cell viability, apoptosis, and LDH leakage were measured after I/R in PC12 cells. The expression and phosphorylation levels of AMPK, NF-κB p65, and P-IκB-α in cytoplasm and nuclear were measured by Western blotting. SiRNA experiment was performed to certify the role of AMPK. The results showed SYB reduced infarct size, improved neurological outcomes, and inhibited brain injury after I/R. In vitro test, SYB treatment alleviated PC12 cells injury and apoptosis and inhibited the inflammatory cytokines (IL-1, IL-6, TNF-α, and COX-2) in a dose-dependent manner. SYB treatment induced AMPK phosphorylation and inhibited NF-κB p65 nuclear translocation both in brain and in PC12 cells. Further studies also showed that the inhibition of NF-κB activity of SYB was through AMPK. In conclusion, SYB protected brain I/R injury through reducing expression of inflammatory cytokines and this effect might be partly due to the inhibition of NF-κB mediated by AMPK
Structural and Magnetic Properties of Ni81Fe19 Thin Film Grown on Si(001) Substrate via Single Graphene Layer
We prepared magnetic thin films Ni81Fe19 on single-crystal Si(001) substrates via single graphene layer through magnetron sputtering for Ni81Fe19 and chemical vapor deposition for graphene. Structural investigation showed that crystal quality of Ni81Fe19 thin films was significantly improved with insertion of graphene layer compared with that directly grown on Si(001) substrate. Furthermore, saturation magnetization of Ni81Fe19/graphene/Si(001) heterostructure increased to 477 emu/cm3 with annealing temperature Ta=400°C, which is much higher than values of Ni81Fe19/Si(001) heterostructures with Ta ranging from 200°C to 400°C
Hub Proteins Involved in RAW 264.7 Macrophages Exposed to Direct Current Electric Field
At present, studies on macrophage proteins mainly focus on biological stimuli, with less attention paid to the responses of macrophage proteins to physical stimuli, such as electric fields. Here, we exploited the electric field-sensitive hub proteins of macrophages. RAW 264.7 macrophages were treated with a direct current electric field (dcEF) (200 mV/mm) for four hours, followed by RNA-Seq analysis. Differentially expressed genes (DEGs) were obtained, followed by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) and protein–protein interaction (PPI) analysis. Eight qPCR-verified DEGs were selected. Subsequently, three-dimensional protein models of DEGs were modeled by Modeller and Rosetta, followed by molecular dynamics simulation for 200 ns with GROMACS. Finally, dcEFs (10, 50, and 500 mV/mm) were used to simulate the molecular dynamics of DEG proteins for 200 ns, followed by trajectory analysis. The dcEF has no obvious effect on RAW 264.7 morphology. A total of 689 DEGs were obtained, and enrichment analysis showed that the steroid biosynthesis pathway was most affected by the dcEF. Moreover, the three-dimensional protein structures of hub proteins were constructed, and trajectory analysis suggested that the dcEF caused an increase in the atomic motion of the protein in a dcEF-intensity-dependent manner. Overall, we provide new clues and a basis for investigating the hub proteins of macrophages in response to electric field stimulation