1,969 research outputs found

    Chemerin receptors in GtoPdb v.2021.3

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    Nomenclature for the chemerin receptors is presented as recommended by NC-IUPHAR [15, 43]). The chemoattractant protein and adipokine, chemerin, has been shown to be the endogenous ligand for both chemerin family receptors. Chemerin1 was the founding family member, and when GPR1 was de-orphanised it was re-named Chermerin2 [43]. Chemerin1 is also activated by the lipid-derived, anti-inflammatory ligand resolvin E1 (RvE1), which is formed via the sequential metabolism of EPA by aspirin-modified cyclooxygenase and lipoxygenase [2, 3]. In addition, two GPCRs for resolvin D1 (RvD1) have been identified: FPR2/ALX, the lipoxin A4 receptor, and GPR32, an orphan receptor [45]

    Chemerin receptors in GtoPdb v.2023.1

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    Nomenclature for the chemerin receptors is presented as recommended by NC-IUPHAR [15, 44]). The chemoattractant protein and adipokine, chemerin, has been shown to be the endogenous ligand for both chemerin family receptors. Chemerin1 was the founding family member, and when GPR1 was de-orphanised it was re-named Chermerin2 [44]. Chemerin1 is also activated by the lipid-derived, anti-inflammatory ligand resolvin E1 (RvE1), which is formed via the sequential metabolism of EPA by aspirin-modified cyclooxygenase and lipoxygenase [2, 3]. In addition, two GPCRs for resolvin D1 (RvD1) have been identified: FPR2/ALX, the lipoxin A4 receptor, and GPR32, an orphan receptor [46]

    Chemerin receptors (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database

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    Nomenclature for the chemerin receptors is presented as recommended by NC-IUPHAR [14, 41]). The chemoattractant protein and adipokine, chemerin, has been shown to be the endogenous ligand for both chemerin family receptors. Chemerin1 was the founding family member, and when GPR1 was de-orphanised it was re-named Chermerin2 [41]. Chemerin1 is also activated by the lipid-derived, anti-inflammatory ligand resolvin E1 (RvE1), which is formed via the sequential metabolism of EPA by aspirin-modified cyclooxygenase and lipoxygenase [2, 3]. In addition, two GPCRs for resolvin D1 (RvD1) have been identified: FPR2/ALX, the lipoxin A4 receptor, and GPR32, an orphan receptor [43]

    Electrical characterization of the soft breakdown failure mode in MgO layers

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    The soft breakdown (SBD) failure mode in 20 nm thick MgO dielectric layers grown on Si substrates was investigated. We show that during a constant voltage stress, charge trapping and progressive breakdown coexist, and that the degradation dynamics is captured by a power-law time dependence. We also show that the SBD current-voltage (I-V) characteristics follow the power-law model I = aVb typical of this conduction mechanism but in a wider voltage window than the one reported in the past for SiO2. The relationship between the magnitude of the current and the normalized differential conductance was analyzed

    Composition Mixing during Blue Straggler Formation and Evolution

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    We use smoothed-particle hydrodynamics to examine differences between direct collisions of single stars and binary star mergers in their roles as possible blue straggler star formation mechanisms. We find in all cases that core helium in the progenitor stars is largely retained in the core of the remnant, almost independent of the type of interaction or the central concentration of the progenitor stars. We have also modelled the subsequent evolution of the hydrostatic remnants, including mass loss and energy input from the hydrodynamical interaction. The combination of the hydrodynamical and hydrostatic models enables us to predict that little mixing will occur during the merger of two globular cluster stars of equal mass. In contrast to the results of Proctor Sills, Bailyn, & Demarque (1995), we find that neither completely mixed nor unmixed models can match the absolute colors of observed blue stragglers in NGC 6397 at all luminosity levels. We also find that the color distribution is probably the crucial test for explanations of BSS formation - if stellar collisions or mergers are the correct mechanisms, a large fraction of the lifetime of the straggler must be spent away from the main sequence. This constraint appears to rule out the possibility of completely mixed models. For NGC 6397, unmixed models predict blue straggler lifetimes ranging from about 0.1 to 4 Gyr, while completely mixed models predict a range from about 0.6 to 4 Gyr.Comment: AASTeX, 28 pg., accepted for ApJ, also available at http://ucowww.ucsc.edu/~erics/bspaper.htm

    Mass transfer in eccentric binaries: the new Oil-on-Water SPH technique

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    To measure the onset of mass transfer in eccentric binaries we have developed a two-phase SPH technique. Mass transfer is important in the evolution of close binaries, and a key issue is to determine the separation at which mass transfer begins. The circular case is well understood and can be treated through the use of the Roche formalism. To treat the eccentric case we use a newly-developed two phase system. The body of the donor star is made up from high-mass "water" particles, whilst the atmosphere is modelled with low-mass "oil" particles. Both sets of particles take part fully in SPH interactions. To test the technique we model circular mass-transfer binaries containing a 0.6 Msun donor star and a 1 Msun white dwarf; such binaries are thought to form cataclysmic variable (CV) systems. We find that we can reproduce a reasonable CV mass-transfer rate, and that our extended atmosphere gives a separation that is too large by aproximately 16%, although its pressure scale height is considerably exaggerated. We use the technique to measure the semi-major axis required for the onset of mass transfer in binaries with a mass ratio of q=0.6 and a range of eccentricities. Comparing to the value obtained by considering the instantaneous Roche lobe at pericentre we find that the radius of the star required for mass transfer to begin decreases systematically with increasing eccentricity.Comment: 9 pages, 8 figures, accepted by MNRA

    Equilibrium Configurations of Strongly Magnetized Neutron Stars with Realistic Equations of State

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    We investigate equilibrium sequences of magnetized rotating stars with four kinds of realistic equations of state (EOSs) of SLy (Douchin et al.), FPS (Pandharipande et al.), Shen (Shen et al.), and LS (Lattimer & Swesty). Employing the Tomimura-Eriguchi scheme to construct the equilibrium configurations. we study the basic physical properties of the sequences in the framework of Newton gravity. In addition we newly take into account a general relativistic effect to the magnetized rotating configurations. With these computations, we find that the properties of the Newtonian magnetized stars, e.g., structure of magnetic field, highly depends on the EOSs. The toroidal magnetic fields concentrate rather near the surface for Shen and LS EOSs than those for SLy and FPS EOSs. The poloidal fields are also affected by the toroidal configurations. Paying attention to the stiffness of the EOSs, we analyze this tendency in detail. In the general relativistic stars, we find that the difference due to the EOSs becomes small because all the employed EOSs become sufficiently stiff for the large maximum density, typically greater than 1015gcm310^{15}\rm{g} \rm{cm}^{-3}. The maximum baryon mass of the magnetized stars with axis ratio q0.7q\sim 0.7 increases about up to twenty percents for that of spherical stars. We furthermore compute equilibrium sequences at finite temperature, which should serve as an initial condition for the hydrodynamic study of newly-born magnetars. Our results suggest that we may obtain information about the EOSs from the observation of the masses of magnetars.Comment: submitted to MNRA

    Maximum gravitational-wave energy emissible in magnetar flares

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    Recent searches of gravitational-wave (GW) data raise the question of what maximum GW energies could be emitted during gamma-ray flares of highly magnetized neutron stars (magnetars). The highest energies (\sim 10^{49} erg) predicted so far come from a model [K. Ioka, Mon. Not. Roy. Astron. Soc. 327, 639 (2001)] in which the internal magnetic field of a magnetar experiences a global reconfiguration, changing the hydromagnetic equilibrium structure of the star and tapping the gravitational potential energy without changing the magnetic potential energy. The largest energies in this model assume very special conditions, including a large change in moment of inertia (which was observed in at most one flare), a very high internal magnetic field, and a very soft equation of state. Here we show that energies of 10^{48}-10^{49} erg are possible under more generic conditions by tapping the magnetic energy, and we note that similar energies may also be available through cracking of exotic solid cores. Current observational limits on gravitational waves from magnetar fundamental modes are just reaching these energies and will beat them in the era of advanced interferometers.Comment: 16 pages, 5 figures, 1 tabl

    New parton distributions from large-x and low-Q^2 data

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    We report results of a new global next-to-leading order fit of parton distribution functions in which cuts on W and Q are relaxed, thereby including more data at high values of x. Effects of target mass corrections (TMCs), higher twist contributions, and nuclear corrections for deuterium data are significant in the large-x region. The leading twist parton distributions are found to be stable to TMC model variations as long as higher twist contributions are also included. The behavior of the d quark as x-->1 is particularly sensitive to the deuterium corrections, and using realistic nuclear smearing models the d-quark distribution at large x is found to be softer than in previous fits performed with more restrictive cuts.Comment: 31 pages, 8 figures. Minor corrections. References added. To appear in Phys.Rev.
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