347 research outputs found

    Mictomagnetic order in Cd0.87Cr1.93V 0.06Se4 semiconductor

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    The complex ac dynamic magnetic susceptibility was used to study the mictomagnetic-like behavior in polycrystalline Cd0:87Cr1:93V0:06Se4 spinel. The temperature dependences of the zero field in-phase (real part) and out-of-phase (imaginary part) components of fundamental susceptibility measured at the oscillating field Hac = 0:5 Oe and at the constant frequency of 125 Hz are characteristic for the mictomagnetic order. These results well correlate with the anomalies in the second and third harmonics of the ac susceptibility indicating the cluster glass

    Electrical and magnetic studies of the CdxCryV zSe4 Spinels

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    The electrical and magnetic investigations carried out on the polycrystalline spinels with the general chemical formula CdxCryVzSe4 (where z = 0:06, 0.12, 0.24, and 0.31) revealed semiconducting and ferromagnetic properties with a Curie temperature of 127.5 K. A step-like structure of the electrical conductivity, ¾(T), was observed for the polycrystal containing 6% V ions in the octahedral sites while the remaining samples showed a typical Arrhenius behaviour of ¾(T). These effects are interpreted in terms of ferromagnetic spin clusters which finally dissolve on going towards the paramagnetic limit including non-stoichiometry

    Spin crossover in CuxCoyCrzSe4 semiconductors

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    Magnetization and magnetic susceptibility measured in the zero-field-cooled mode were used to study the spin crossover transition in polycrystalline CuxCoyCrzSe4 compounds. With increasing Co content a transition from ferromagnetic order via ferrimagnetic one to antiferromagnetic-like behaviour was observed. This transition is accompanied with a lowering symmetry from cubic to monoclinic and for the latter the spin crossover phenomenon occurs. These results are considered in a framework of the ligand–field split and the spin–orbit coupling

    Subjective self-assessment of physical activity is negatively affected by monitoring awareness in subjects with mild cognitive impairment : A crossover randomised controlled trial

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    Publisher Copyright: © 2021 Verduci Editore s.r.l. All rights reserved.OBJECTIVE: Physical activity plays an important role in maintaining mental and physical health. This study assessed the effect of physical activity monitoring awareness on the physical activity level and subjective self-assessment of physical activity in middle-aged subjects with normal cognitive function (NCF) and mild cognitive impairment (MCI). PATIENTS AND METHODS: Thirty-five subjects aged 50-65 years with NCF and MCI were randomised into two experimental groups, each taking part in two one-week intervention periods. Subjects in group A were not aware that their physical activity was monitored in the first week (phase I) and were aware of the monitoring in the second week (phase II), whereas it was the opposite order for group B. Physical activity was assessed using the ActiGraph GT9X accelerometer and International Physical Activity Questionnaire (IPAQ). RESULTS: A total of 32 subjects (MCI: n = 12, NCF: n = 20) completed both intervention periods, with MCI subjects having significantly lower objectively assessed physical activity than NCF participants. Moreover, subjectively assessed physical activity in the MCI group was significantly higher when the participants were unaware of physical activity monitoring. A significant phase-group interaction was found in total (MET-min/d: P = 0.0072; min/d: P = 0.0194) and moderate (MET-min/d: P = 0.0015; min/d: P = 0.0020) physical activity as well as energy expenditure (p = 0.0366) assessed by the IPAQ and in the percentage of sedentary behaviour (p = 0.0330) and the average number of steps (p = 0.0342) assessed by ActiGraph. CONCLUSIONS: The awareness of physical activity assessment might decrease the ability to subjectively assess physical activity in subjects with MCI.Peer reviewe

    Correction to: The novel compound PBT434 prevents iron mediated neurodegeneration and alpha-synuclein toxicity in multiple models of Parkinson's disease.

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    Following publication of the original article [1], the author identified an error in Fig. 4E. The data and statistics were correct, but the synaptophysin blot was incorrect. The incorrect (Fig. 1) and correct figure (Fig. 2) are shown in this correction article. (Figure presented.)

    The novel compound PBT434 prevents iron mediated neurodegeneration and alpha-synuclein toxicity in multiple models of Parkinson's disease

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    Elevated iron in the SNpc may play a key role in Parkinson's disease (PD) neurodegeneration since drug candidates with high iron affinity rescue PD animal models, and one candidate, deferirpone, has shown efficacy recently in a phase two clinical trial. However, strong iron chelators may perturb essential iron metabolism, and it is not yet known whether the damage associated with iron is mediated by a tightly bound (eg ferritin) or lower-affinity, labile, iron pool. Here we report the preclinical characterization of PBT434, a novel quinazolinone compound bearing a moderate affinity metal-binding motif, which is in development for Parkinsonian conditions. In vitro, PBT434 was far less potent than deferiprone or deferoxamine at lowering cellular iron levels, yet was found to inhibit iron-mediated redox activity and iron-mediated aggregation of α-synuclein, a protein that aggregates in the neuropathology. In vivo, PBT434 did not deplete tissue iron stores in normal rodents, yet prevented loss of substantia nigra pars compacta neurons (SNpc), lowered nigral α-synuclein accumulation, and rescued motor performance in mice exposed to the Parkinsonian toxins 6-OHDA and MPTP, and in a transgenic animal model (hA53T α-synuclein) of PD. These improvements were associated with reduced markers of oxidative damage, and increased levels of ferroportin (an iron exporter) and DJ-1. We conclude that compounds designed to target a pool of pathological iron that is not held in high-affinity complexes in the tissue can maintain the survival of SNpc neurons and could be disease-modifying in PD

    Measurements of Dihadron Correlations Relative to the Event Plane in Au+Au Collisions at sNN=200\sqrt{s_{NN}}=200 GeV

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    Dihadron azimuthal correlations containing a high transverse momentum (\pt) trigger particle are sensitive to the properties of the nuclear medium created at RHIC through the strong interactions occurring between the traversing parton and the medium, i.e. jet-quenching. Previous measurements revealed a strong modification to dihadron azimuthal correlations in Au+Au collisions with respect to \pp\ and \dAu\ collisions. The modification increases with the collision centrality, suggesting a path-length dependence to the jet-quenching effect. This paper reports STAR measurements of dihadron azimuthal correlations in mid-central (20-60\%) Au+Au collisions at \snn=200~GeV as a function of the trigger particle's azimuthal angle relative to the event plane, \phis=|\phit-\psiEP|. The azimuthal correlation is studied as a function of both the trigger and associated particle \pt. The subtractions of the combinatorial background and anisotropic flow, assuming Zero Yield At Minimum (\zyam), are described. The away-side correlation is strongly modified, and the modification varies with \phis, which is expected to be related to the path-length that the away-side parton traverses. The pseudo-rapidity (\deta) dependence of the near-side correlation, sensitive to long range \deta correlations (the ridge), is also investigated. The ridge and jet-like components of the near-side correlation are studied as a function of \phis. The ridge appears to drop with increasing \phis while the jet-like component remains approximately constant. ...Comment: 50 pages, 39 figures, 6 table

    System size and energy dependence of near-side di-hadron correlations

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    Two-particle azimuthal (Δϕ\Delta\phi) and pseudorapidity (Δη\Delta\eta) correlations using a trigger particle with large transverse momentum (pTp_T) in dd+Au, Cu+Cu and Au+Au collisions at sNN\sqrt{s_{{NN}}} =\xspace 62.4 GeV and 200~GeV from the STAR experiment at RHIC are presented. The \ns correlation is separated into a jet-like component, narrow in both Δϕ\Delta\phi and Δη\Delta\eta, and the ridge, narrow in Δϕ\Delta\phi but broad in Δη\Delta\eta. Both components are studied as a function of collision centrality, and the jet-like correlation is studied as a function of the trigger and associated pTp_T. The behavior of the jet-like component is remarkably consistent for different collision systems, suggesting it is produced by fragmentation. The width of the jet-like correlation is found to increase with the system size. The ridge, previously observed in Au+Au collisions at sNN\sqrt{s_{{NN}}} = 200 GeV, is also found in Cu+Cu collisions and in collisions at sNN\sqrt{s_{{NN}}} =\xspace 62.4 GeV, but is found to be substantially smaller at sNN\sqrt{s_{{NN}}} =\xspace 62.4 GeV than at sNN\sqrt{s_{{NN}}} = 200 GeV for the same average number of participants (Npart \langle N_{\mathrm{part}}\rangle). Measurements of the ridge are compared to models.Comment: 17 pages, 14 figures, submitted to Phys. Rev.
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