921 research outputs found
Kondo Quantum Dots and the Novel Kondo-doublet interaction
We analyze the interactions between two Kondo Quantum Dots connected to a
Rashba-active Quantum Wire. We find that the Kondo-doublet interaction, at an
inter-dot distance of the order of the wire Fermi length, is over an order of
magnitude greater than the RKKY interaction. The effects induced on the
Kondo-doublet interaction by the wire spin-orbit coupling can be used to
control the Quantum Dots spin-spin correlation. These results imply that the
widely used assumption that the RKKY is the dominant interaction between
Anderson impurities must be revised.Comment: 4 pages, 4 figs, accepted for publication in PRL. title changed and
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Inherited epithelial transporter disorders—an overview
Summary: In the late 1990s, the identification of transporters and transporter-associated genes progressed substantially due to the development of new cloning approaches such as expression cloning and, subsequently, to the implementation of the human genome project. Since then, the role of many transporter genes in human diseases has been elucidated. In this overview, we focus on inherited disorders of epithelial transporters. In particular, we review genetic defects of the genes encoding glucose transporters (SLC2 and SLC5 families) and amino acid transporters (SLC1, SLC3, SLC6 and SLC7 families
Liquid/Liquid Extraction Kinetics of Eu(III) and Am(III) by Extractants Designed for the Industrial Reprocessing of Nuclear Wastes
Results about the kinetics of extraction of Eu(III) and Am(III) by extractants designed for the industrial reprocessing of nuclear wastes are reported. They were obtained using the rotating membrane cell (RMC) technique. Extraction and stripping kinetic rate constants were determined for various compositions of the aqueous and organic phases. The transfer was studied at liquid/liquid interfaces between an aqueous nitric acid solution and an organic solvent containing the diglycolamide extractant molecule N,N,N′,N′-tetra-n-octyl-diglycolamide (TODGA) or a mixture of the bipyridine molecule CyMe4BTBP with TODGA (the latter being used as a phase-transfer catalyst), dissolved in an aliphatic diluent. In some experiments, an aqueous ligand (a sulfonated bis triazinyl pyridine, SO3-Ph-BTP, or a PyTri-diol) was added to the aqueous phase as a stripping agent. The diffusion coefficients of Eu(III) and Am(III), which are key in the analysis of the kinetic data, were measured using the RMC and the closed capillary technique. Whenever possible, mechanisms are proposed to interpret the experimental results
Neural detection of complex sound sequences in the absence of consciousness.
The neural response to a violation of sequences of identical sounds is a typical example of the brain's sensitivity to auditory regularities. Previous literature interprets this effect as a pre-attentive and unconscious processing of sensory stimuli. By contrast, a violation to auditory global regularities, i.e. based on repeating groups of sounds, is typically detectable when subjects can consciously perceive them. Here, we challenge the notion that global detection implies consciousness by testing the neural response to global violations in a group of 24 patients with post-anoxic coma (three females, age range 45-87 years), treated with mild therapeutic hypothermia and sedation. By applying a decoding analysis to electroencephalographic responses to standard versus deviant sound sequences, we found above-chance decoding performance in 10 of 24 patients (Wilcoxon signed-rank test, P < 0.001), despite five of them being mildly hypothermic, sedated and unarousable. Furthermore, consistently with previous findings based on the mismatch negativity the progression of this decoding performance was informative of patients' chances of awakening (78% predictive of awakening). Our results show for the first time that detection of global regularities at neural level exists despite a deeply unconscious state
Implementation of cisternostomy as adjuvant to decompressive craniectomy for the management of severe brain trauma.
To evaluate the value of an adjuvant cisternostomy (AC) to decompressive craniectomy (DC) for the management of patients with severe traumatic brain injury (sTBI).
A single-center retrospective quality control analysis of a consecutive series of sTBI patients surgically treated with AC or DC alone between 2013 and 2018. A subgroup analysis, "primary procedure" and "secondary procedure", was also performed. We examined the impact of AC vs. DC on clinical outcome, including long-term (6 months) extended Glasgow outcome scale (GOS-E), the duration of postoperative ventilation, and intensive care unit (ICU) stay, mortality, Glasgow coma scale at discharge, and time to cranioplasty. We also evaluated and analyzed the impact of AC vs. DC on post-procedural intracranial pressure (ICP) and brain tissue oxygen (PbO <sub>2</sub> ) values as well as the need for additional osmotherapy and CSF drainage.
Forty patients were examined, 22 patients in the DC group, and 18 in the AC group. Compared with DC alone, AC was associated with significant shorter duration of mechanical ventilation and ICU stay, as well as better Glasgow coma scale at discharge. Mortality rate was similar. At 6-month, the proportion of patients with favorable outcome (GOS-E ≥ 5) was higher in patients with AC vs. DC [10/18 patients (61%) vs. 7/20 (35%)]. The outcome difference was particularly relevant when AC was performed as primary procedure (61.5% vs. 18.2%; p = 0.04). Patients in the AC group also had significant lower average post-surgical ICP values, higher PbO <sub>2</sub> values and required less osmotic treatments as compared with those treated with DC alone.
Our preliminary single-center retrospective data indicate that AC may be beneficial for the management of severe TBI and is associated with better clinical outcome. These promising results need further confirmation by larger multicenter clinical studies. The potential benefits of cisternostomy should not encourage its universal implementation across trauma care centers by surgeons that do not have the expertise and instrumentation necessary for cisternal microsurgery. Training in skull base and vascular surgery techniques for trauma care surgeons would avoid the potential complications associated with this delicate procedure
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Highly efficient separation of actinides from lanthanides by a phenanthroline-derived bis-triazine ligand
The synthesis, lanthanide complexation, and solvent ex- traction of actinide(III) and lanthanide(III) radiotracers from nitric acid solutions by a phenanthroline-derived quadridentate bis-triazine ligand are described. The ligand separates Am(III) and Cm(III) from the lanthanides with remarkably high efficiency, high selectivity, and fast extraction kinetics compared to its 2,2'-bipyridine counterpart. Structures of the 1:2 bis-complexes of the ligand with Eu(III) and Yb(III) were elucidated by X-ray crystallography and force field calculations, respec-tively. The Eu(III) bis-complex is the first 1:2 bis-complex of a quadridentate bis-triazine ligand to be characterized by crystallography. The faster rates of extraction were verified by kinetics measurements using the rotating membrane cell technique in several diluents. The improved kinetics of metal ion extraction are related to the higher surface activity of the ligand at the phase interface. The improvement in the ligand's properties on replacing the bipyridine unit with a phenanthroline unit far exceeds what was anticipated based on ligand design alone
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