Search results for " Spin"
showing 10 items of 1036 documents
Brain erythropoietin fine-tunes a counterbalance between neurodifferentiation and microglia in the adult hippocampus
2021
In adult cornu ammonis hippocampi, erythropoietin (EPO) expression drives the differentiation of new neurons,independent of DNA synthesis, and increases dendritic spine density. This substantial brain hardwareupgrade is part of a regulatory circle: during motor-cognitive challenge, neurons experience ‘‘functional’’hypoxia, triggering neuronal EPO production, which in turn promotes improved performance. Here, weshow an unexpected involvement of resident microglia. During EPO upregulation and stimulated neurodifferentiation,either by functional or inspiratory hypoxia, microglia numbers decrease. Treating mice with recombinanthuman (rh)EPO or exposure to hypoxia recapitulates these changes and…
The fine structure of denervated and reinnervated muscle spindles: morphometric study of intrafusal muscle fibers.
1979
The fine structure of normal, denervated, and reinnervated muscle spindles in lower lumbrical muscles of rats was studied morphometrically at time intervals ranging from 3-14 months. In control spindles, the mean transverse area of mitochondria was estimated to be more than twice as large in nuclear chain than in typical nuclear bag fibers. Following denervation, there was a severe decrease of the mean number and transverse area of mitochondria, and a moderate, but statistically significant decrease of the mean transverse area of intrafusal muscle fibers (IMFs) despite an increase of the number of IMFs. At 12-14 months of reinnervation, changes of the transverse areas of IMFs were statistic…
Continuous-Variable Tomography of Solitary Electrons
2019
A method for characterising the wave-function of freely-propagating particles would provide a useful tool for developing quantum-information technologies with single electronic excitations. Previous continuous-variable quantum tomography techniques developed to analyse electronic excitations in the energy-time domain have been limited to energies close to the Fermi level. We show that a wide-band tomography of single-particle distributions is possible using energy-time filtering and that the Wigner representation of the mixed-state density matrix can be reconstructed for solitary electrons emitted by an on-demand single-electron source. These are highly localised distributions, isolated fro…
Field-Induced Slow Magnetic Relaxation in a Mononuclear Manganese(III)-Porphyrin Complex
2015
We report on a novel manganese(III)-porphyrin complex with the formula [Mn(III) (TPP)(3,5-Me2 pyNO)2 ]ClO4 ⋅CH3 CN (2; 3,5-Me2 pyNO=3,5-dimethylpyridine N-oxide, H2 TPP=5,10,15,20-tetraphenylporphyrin), in which the Mn(III) ion is six-coordinate with two monodentate 3,5-Me2 pyNO molecules and a tetradentate TPP ligand to build a tetragonally elongated octahedral geometry. The environment in 2 is responsible for the large and negative axial zero-field splitting (D=-3.8 cm(-1) ), low rhombicity (E/|D|=0.04) of the high-spin Mn(III) ion, and, ultimately, for the observation of slow magnetic-relaxation effects (Ea =15.5 cm(-1) at H=1000 G) in this rare example of a manganese-based single-ion ma…
Pulsed EPR determination of water accessibility to spin-labeled amino acid residues in LHCIIb.
2009
Membrane proteins reside in a structured environment in which some of their residues are accessible to water, some are in contact with alkyl chains of lipid molecules, and some are buried in the protein. Water accessibility of residues may change during folding or function-related structural dynamics. Several techniques based on the combination of pulsed electron paramagnetic resonance (EPR) with site-directed spin labeling can be used to quantify such water accessibility. Accessibility parameters for different residues in major plant light-harvesting complex IIb are determined by electron spin echo envelope modulation spectroscopy in the presence of deuterated water, deuterium contrast in …
GW170817: Measurements of Neutron Star Radii and Equation of State
2018
On 17 August 2017, the LIGO and Virgo observatories made the first direct detection of gravitational waves from the coalescence of a neutron star binary system. The detection of this gravitational-wave signal, GW170817, offers a novel opportunity to directly probe the properties of matter at the extreme conditions found in the interior of these stars. The initial, minimal-assumption analysis of the LIGO and Virgo data placed constraints on the tidal effects of the coalescing bodies, which were then translated to constraints on neutron star radii. Here, we expand upon previous analyses by working under the hypothesis that both bodies were neutron stars that are described by the same equation…
Sivers asymmetry extracted in SIDIS at the hard scales of the Drell-Yan process at COMPASS
2017
Proton transverse-spin azimuthal asymmetries are extracted from the COMPASS 2010 semi-inclusive hadron measurements in deep inelastic muon-nucleon scattering in those four regions of the photon virtuality $Q^2$, which correspond to the four regions of the di-muon mass $\sqrt{Q^2}$ used in the ongoing analysis of the COMPASS Drell-Yan measurements. This allows for a future direct comparison of the nucleon transverse-momentum-dependent parton distribution functions extracted from these two alternative measurements. Various two-dimensional kinematic dependences are presented for the azimuthal asymmetries induced by the Sivers transverse-momentum-dependent parton distribution function. The inte…
Intraoperative microvascular Doppler monitoring of blood flow within a spinal dural arteriovenous fistula: a precious surgical tool. Case report.
2001
The authors describe a case of spinal arteriovenous fistula (AVF) treated by a microvauscular Doppler–assisted surgical interruption of the arterialized vein. Microvascular Doppler monitoring represents a valid, widely available, non-invasive tool that enables identification, through flow spectrum analysis, of components of this type of vascular malformation. In this case because the location of the fistula was identified prior to opening the dura only minimally invasive surgery was required. Direct recordings of the arterialized draining vein and the nidus of the fistula demonstrated a pathological spectrum caused by the arterial supply and the disturbed venous outflow in which a high-resi…
EUROPA 2020 IN SICILIA: SPIN-OFF DI RICERCA, DISTRETTI HIGH-TECH E STRATEGIE DI INNOVAZIONE ISTITUZIONALE
2014
Gli indicatori di posizione che quantificano le priorità della strategia Europa 2020 denunciano un ritardo nello sviluppo della Sicilia rispetto alle altre regioni italiane. Per ridurre tali divari si propongono strategie trainate dall`innovazione quali ad esempio distretti tecnologici e spin-off di ricerca. Dopo un excursus di letteratura volto a mettere a confronto queste due forme di innovazione tecnologica ed organizzativa, viene proposto un esercizio empirico che intende verificare quanto la creazione di imprenditorialità da parte dell’Università può contribuire alla riduzione dei divari di sviluppo. Si intende proporre alcune suggerimenti di policy per aumentare la loro efficacia nell…