710 research outputs found
Superconductivity in Sr2RuO4-Sr3Ru2O7 eutectic crystals
Superconducting behavior has been observed in the Sr2RuO4-Sr3Ru2O7 eutectic
system as grown by the flux-feeding floating zone technique. A supercurrent
flows across a single interface between Sr2RuO4 and Sr3Ru2O7 areas at distances
that are far beyond those expected in a conventional proximity scenario. The
current-voltage characteristics within the Sr3Ru2O7 macrodomain, as extracted
from the eutectic, exhibit signatures of superconductivity in the bilayered
ruthenate. Detailed microstructural, morphological and compositional analyses
address issues on the concentration and the size of Sr2RuO4 inclusions within
the Sr3Ru2O7 matrix. We speculate on the possibility of inhomogeneous
superconductivity in the eutectic Sr3Ru2O7 and exotic pairing induced by the
Sr2RuO4 inclusions.Comment: Pages 4, figures 3, submitted to Phys. Rev. Let
Influence of Topological Edge States on the Properties of Al/Bi2Se3/Al Hybrid Josephson Devices
In superconductor-topological insulator-superconductor hybrid junctions, the
barrier edge states are expected to be protected against backscattering, to
generate unconventional proximity effects, and, possibly, to signal the
presence of Majorana fermions. The standards of proximity modes for these types
of structures have to be settled for a neat identification of possible new
entities. Through a systematic and complete set of measurements of the
Josephson properties we find evidence of ballistic transport in coplanar
Al-Bi2Se3-Al junctions that we attribute to a coherent transport through the
topological edge state. The shunting effect of the bulk only influences the
normal transport. This behavior, which can be considered to some extent
universal, is fairly independent of the specific features of superconducting
electrodes. A comparative study of Shubnikov - de Haas oscillations and
Scanning Tunneling Spectroscopy gave an experimental signature compatible with
a two dimensional electron transport channel with a Dirac dispersion relation.
A reduction of the size of the Bi2Se3 flakes to the nanoscale is an unavoidable
step to drive Josephson junctions in the proper regime to detect possible
distinctive features of Majorana fermions.Comment: 11 pages, 14 figure
Metabolic reprogramming promotes myogenesis during aging
Sarcopenia is the age-related progressive loss of skeletal muscle mass and strength finally leading to poor physical performance. Impaired myogenesis contributes to the pathogenesis of sarcopenia, while mitochondrial dysfunctions are thought to play a primary role in skeletal muscle loss during aging. Here we studied the link between myogenesis and metabolism. In particular, we analyzed the effect of the metabolic modulator trimetazidine (TMZ) on myogenesis in aging. We show that reprogramming the metabolism by TMZ treatment for 12 consecutive days stimulates myogenic gene expression in skeletal muscle of 22-month-old mice. Our data also reveal that TMZ increases the levels of mitochondrial proteins and stimulates the oxidative metabolism in aged muscles, this finding being in line with our previous observations in cachectic mice. Moreover, we show that, besides TMZ also other types of metabolic modulators (i.e., 5-Aminoimidazole-4-Carboxamide Ribofuranoside-AICAR) can stimulate differentiation of skeletal muscle progenitors in vitro. Overall, our results reveal that reprogramming the metabolism stimulates myogenesis while triggering mitochondrial proteins synthesis in vivo during aging. Together with the previously reported ability of TMZ to increase muscle strength in aged mice, these new data suggest an interesting non-invasive therapeutic strategy which could contribute to improving muscle quality and neuromuscular communication in the elderly, and counteracting sarcopenia
Paramagnetic effect in YBaCuO grain boundary junctions
A detailed investigation of the magnetic response of YBaCuO grain boundary
Josephson junctions has been carried out using both radio-frequency
measurements and Scanning SQUID Microscopy. In a nominally zero-field-cooled
regime we observed a paramagnetic response at low external fields for 45 degree
asymmetric grain boundaries. We argue that the observed phenomenology results
from the d-wave order parameter symmetry and depends on Andreev bound states.Comment: To be published in Phys. Rev.
A nosocomial outbreak of 2009 pandemic influenza A(H1N1) in a paediatric oncology ward in Italy, October – November 2009
A nosocomial outbreak of 2009 pandemic influenza A(H1N1), with eight confirmed cases, occurred in a paediatric oncology ward in Italy, in October/November 2009. The fact that one case was infected despite being isolated and without contact to a symptomatic patient, hints towards potential transmission through a health care worker (HCW) and underlines the importance of vaccination of HCW who are involved in the care of critically ill patients
An unprecedented case of cranial surgery in Longobard Italy (6th–8th century) using a cruciform incision
The Longobard necropolis of Castel Trosino dates from the 6th to the 8th century CE. Among the tombs excavated, the skull of an older female shows the first evidence of a cross-shaped bone modification on a living subject. Macroscopic, microscopic, and CT scan analyses revealed signs of at least two sets of scraping marks. Specifically, SEM analysis shows that perimortem bone-scraping traces are present on the skull. Both healed and non-healed defects suggest that the woman has received at least twice intentional bone modifications to address her condition. This is the first evidence of a cross-shaped therapeutic intervention on a living subject
Strong interconversion of non-polar phonons and Josephson plasma oscillations induced by equilibrium Josephson currents in high T_c superconductors
We analyze consequences of dynamical modulations of Josephson current by
non-polar lattice mode in the Josephson junction barrier. In the high
junctions, the effect of such modulations can be anomalously strong due to the
proximity of the insulating barrier to the superconducting state. Accordingly,
the interconversion of sound (as well as other non-polar phonons) and the
Josephson plasma oscillations mediated by stationary Josephson currents, which
may be present in the junction due to various reasons, becomes possible. We
suggest that this effect can be employed for imaging of the stationary
Josephson currents. Estimates of the effect are given.Comment: 11 RevTeX pages, no figure
Expression of orexin A and its receptor 1 in the rat epididymis.
The hypothalamic peptide orexin A (oxA) derives from the proteolytic cleavage of the precursor molecule
prepro-orexin. It binds with the high affinity G-protein-coupled orexin receptor 1 (OX1R). Here, we report
the detection of oxA and OX1R in the principal cells of the rat caudal epididymis by immunohistochemistry.
Both oxA and OX1R immunolabelling showed cytoplasmic supranuclear localization, filling the apical portion
of the cells. The expression of prepro-orexin and OX1R mRNA transcripts in the rat epididymis was assessed
by reverse-transcriptase polymerase chain reaction, while the presence of both these proteins in the tissue
was confirmed by Western blotting analysis. Our findings provide the evidence for the presence of oxA and
OX1R in the rat epididymis, and demonstrate that both proteins are locally synthesised, thus suggesting a
role for oxA in governing the fertilizing capability of the immature male gamete
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