1,850 research outputs found
Atomic and electronic structure of ultra-thin Al/AlOx/Al interfaces
Interfaces between metals based on AlO represent the most popular basis
for Josephson junctions or, more recently, also for junctions exhibiting
substantial tunneling magneto-resistance. We have performed a computational
study of possible local geometric structures of such interfaces at the
ab-initio DFT/GGA level of approximation to complement recent experimental data
on ultra-thin AlO-based interfaces. We present two competing structures
that we characterise with their electronic properties: fragmentation and
interface energies.Comment: Presented at the ECOSS24, submitted to the proceeding - special issue
of Surf. Scienc
Rab8a and Rab8b are essential for several apical transport pathways but insufficient for ciliogenesis
The small GTP-binding protein Rab8 is known to play an essential role in intracellular transport and cilia formation. We have previously demonstrated that Rab8a is required for localising apical markers in various organisms. Rab8a has a closely related isoform, Rab8b. To determine whether Rab8b can compensate for Rab8a, we generated Rab8b-knockout mice. Although the Rab8b-knockout mice did not display an overt phenotype, Rab8a and Rab8b double-knockout mice exhibited mislocalisation of apical markers and died earlier than Rab8a-knockout mice. The apical markers accumulated in three intracellular patterns in the double-knockout mice. However, the localisation of basolateral and/or dendritic markers of the double-knockout mice seemed normal. The morphology and the length of various primary and/or motile cilia, and the frequency of ciliated cells appeared to be identical in control and double-knockout mice. However, an additional knockdown of Rab10 in double-knockout cells greatly reduced the percentage of ciliated cells. Our results highlight the compensatory effect of Rab8a and Rab8b in apical transport, and the complexity of the apical transport process. In addition, neither Rab8a nor Rab8b are required for basolateral and/or dendritic transport. However, simultaneous loss of Rab8a and Rab8b has little effect on ciliogenesis, whereas additional loss of Rab10 greatly affects ciliogenesis
Pressure study of the new iron-based superconductor K0.8Fe2Se2
We investigated pressure effects on transition temperature (Tc) of the new
iron-based superconductor K0.8Fe2Se2 using a BeCu/NiCrAl hybrid-type clamped
piston-cylinder cell. The Tc(onset) was 33K at 0.85 GPa. With increasing
pressure, Tc(onset) gradually increased and reached 36.6 K at 2.03 GPa.Comment: 8 pages, 3 figure
Temperature dependence of iron local magnetic moment in phase-separated superconducting chalcogenide
We have studied local magnetic moment and electronic phase separation in
superconducting KFeSe by x-ray emission and absorption
spectroscopy. Detailed temperature dependent measurements at the Fe K-edge have
revealed coexisting electronic phases and their correlation with the transport
properties. By cooling down, the local magnetic moment of Fe shows a sharp drop
across the superconducting transition temperature (T) and the coexisting
phases exchange spectral weights with the low spin state gaining intensity at
the expense of the higher spin state. After annealing the sample across the
iron-vacancy order temperature, the system does not recover the initial state
and the spectral weight anomaly at T as well as superconductivity
disappear. The results clearly underline that the coexistence of the low spin
and high spin phases and the transitions between them provide unusual magnetic
fluctuations and have a fundamental role in the superconducting mechanism of
electronically inhomogeneous KFeSe system.Comment: 6 pages, 5 figure
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