736 research outputs found
Competition between intrinsic and extrinsic effects in the quenching of the superconducting state in FeSeTe thin films
We report the first experimental observation of the quenching of the
superconducting state in current-voltage characteristics of an iron-based
superconductor, namely, in FeSeTe thin films. Based on available theoretical
models, our analysis suggests the presence of an intrinsic flux-flow electronic
instability along with non-negligible extrinsic thermal effects. The
coexistence and competition of these two mechanisms classify the observed
instability as halfway between those of low-temperature and of high-temperature
superconductors, where thermal effects are respectively largely negligible or
predominant.Comment: 7 pages, 5 figures, fixed typo
Stability mechanisms of high current transport in iron-chalcogenides superconducting films
The improvement in the fabrication techniques of iron-based superconductors
have made these materials real competitors of high temperature superconductors
and MgB. In particular, iron-chalcogenides have proved to be the most
promising for the realization of high current carrying tapes. But their use on
a large scale cannot be achieved without the understanding of the current
stability mechanisms in these compounds. Indeed, we have recently observed the
presence of flux flow instabilities features in Fe(Se,Te) thin films grown on
CaF. Here we present the results of current-voltage characterizations at
different temperatures and applied magnetic fields on Fe(Se,Te) microbridges
grown on CaF. These results will be analyzed from the point of view of the
most validated models with the aim to identify the nature of the flux flow
instabilities features (i.e., thermal or electronic), in order to give a
further advance to the high current carrying capability of iron-chalcogenide
superconductors.Comment: 4 pages, 3 figure
Delayed surgery in neurologically intact patients affected by thoraco-lumbar junction burst fractures: to reduce pain and improve quality of life
This is a retrospective study on 18 patients affected by thoraco-lumbar junction burst fractures (TLJBF) A3 or A4 at computed tomography (CT) scan who referred to our hospital. To assess the surgical results in terms of pain and quality of life in a series of neurologically intact patients affected by TLJBF who underwent surgery after 3-4 months from the injury. In literature there is controversy if pain could be an indication for surgery in TLJBF and series of patients conservatively managed with success have been reported
The endophytic microbiome of X. fastidiosa susceptible and resistant olives
A multi-factorial strategy is required to co-exist with X. fastidiosa infections, which are
devastating olive trees in the southern area of Apulia (Italy). Observations in the outbreak area can
provide information on potential approaches for containment. Olive cvs Leccino and FS17 show
lessened symptoms and host lower bacterial populations (1,2) than cvs Ogliarola salentina, Cellina di
NardĂČ and Kalamata. We are evaluating whether microbial communities inhabiting the xylem vessels
of olive cvs showing different susceptibilities to X. fastidiosa -infection play a role in resistance. To
explore these endophytic microbiomes, a whole-metagenome shotgun analysis is currently ongoing. X.
fastidiosa -infected and healthy olive plants of the cultivars FS17, Leccino and Kalamata, were
selected from the same plot to limit the influence of diverse soil composition and crop management.
Shotgun sequencing of DNA extracted from the xylem tissues will be used to investigate the
microbiome community by bio-informatic analysis. Moreover, efforts to isolate culturable
microorganisms to be used in antagonistic assays against X. fastidiosa, will be performed.
Concurrently, the X. fastidiosa-biocontrol potency of Paraburkholderia phytofirmans PsJN strain,
whose beneficial effects in the reduction of symptoms in Pierceâs Disease (3) have been recently
described, are under evaluation. We are testing the ability of P. phytofirmans to colonise xylem
vessels and interact with X. fastidiosa in tobacco and olive
Exercise intensity regulates cytokine and klotho responses in men
Background Short-term exercise training programs that consist of moderate intensity endurance training or high intensity interval training have become popular choices for healthy lifestyle modifications, with as little as two weeks of training being shown to improve cardiorespiratory fitness and whole-body glucose metabolism. An emerging concept in exercise biology is that exercise stimulates the release of cytokines and other factors into the blood that contribute to the beneficial effects of exercise on metabolism, but whether these factors behave similarly in response to moderate and high intensity short term training is not known. Here, we determined the effects of two short-term exercise training programs on the concentrations of select secreted cytokines and Klotho, a protein involved in anti-aging. Methods Healthy, sedentary men (n = 22) were randomized to moderate intensity training (MIT) or sprint intensity training (SIT) treatment groups. SIT consisted of 6 sessions over 2 weeks of 6 x 30 s all out cycle ergometer sprints with 4 min of recovery between sprints. MIT consisted of 6 sessions over 2 weeks of cycle ergometer exercise at 60% VO2peak, gradually increasing in duration from 40 to 60 min. Blood was taken before the intervention and 48 h after the last training session, and glucose uptake was measured using [18F]FDG-PET/CT scanning. Cytokines were measured by multiplex and Klotho concentrations by ELISA. Results Both training protocols similarly increased VO2peak and decreased fat percentage and visceral fat (P Conclusion Short-term exercise training at markedly different intensities similarly improves cardiovascular fitness but results in intensity-specific changes in cytokine responses to exercise.</div
Dimensionality of superconductivity in the transition metal pnictide WP
We report theoretical and experimental results on transition metal pnictide
WP. The theoretical outcomes based on tight-binding calculations and density
functional theory indicate that WP exhibits the nonsymmorphic symmetries and is
an anisotropic three-dimensional superconductor. This conclusion is supported
by magnetoresistance experimental data as well as by the investigation of the
superconducting fluctuations of the conductivity in the presence of a magnetic
external field, both underlining a three dimensional behavior.Comment: 8 pages, 7 figure
Mass and charge identification of fragments detected with the Chimera Silicon-CsI(Tl) telescopes
Mass and charge identification of charged products detected with
Silicon-CsI(Tl) telescopes of the Chimera apparatus is presented. An
identification function, based on the Bethe-Bloch formula, is used to fit
empirical correlation between Delta E and E ADC readings, in order to
determine, event by event, the atomic and mass numbers of the detected charged
reaction products prior to energy calibration.Comment: 24 pages, 7 .jpg figures, submitted to Nucl.Instr.
Biallelic loss-of-function variants in <i>CACHD1 </i>cause a novel neurodevelopmental syndrome with facial dysmorphism and multisystem congenital abnormalities
Purpose We established the genetic etiology of a syndromic neurodevelopmental condition characterized by variable cognitive impairment, recognizable facial dysmorphism, and a constellation of extra-neurological manifestations. Methods We performed phenotypic characterization of 6 participants from 4 unrelated families presenting with a neurodevelopmental syndrome and used exome sequencing to investigate the underlying genetic cause. To probe relevance to the neurodevelopmental phenotype and craniofacial dysmorphism, we established two- and three-dimensional human stem cell-derived neural models and generated a stable cachd1 zebrafish mutant on a transgenic cartilage reporter line. Results Affected individuals showed mild cognitive impairment, dysmorphism featuring oculo-auriculo abnormalities, and developmental defects involving genitourinary and digestive tracts. Exome sequencing revealed biallelic putative loss-of-function variants in CACHD1 segregating with disease in all pedigrees. RNA sequencing in CACHD1-depleted neural progenitors revealed abnormal expression of genes with key roles in Wnt signaling, neurodevelopment, and organ morphogenesis. CACHD1 depletion in neural progenitors resulted in reduced percentages of post-mitotic neurons and enlargement of 3D neurospheres. Homozygous cachd1 mutant larvae showed mandibular patterning defects mimicking human facial dysmorphism. Conclusion Our findings support the role of loss-of-function variants in CACHD1 as the cause of a rare neurodevelopmental syndrome with facial dysmorphism and multisystem abnormalities
- âŠ