3,271 research outputs found

    δ\delta meson effects on neutron stars in the modified quark-meson coupling model

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    The properties of neutron stars are investigated by including δ\delta meson field in the Lagrangian density of modified quark-meson coupling model. The Σ−\Sigma^- population with δ\delta meson is larger than that without δ\delta meson at the beginning, but it becomes smaller than that without δ\delta meson as the appearance of Ξ−\Xi^-. The δ\delta meson has opposite effects on hadronic matter with or without hyperons: it softens the EOSes of hadronic matter with hyperons, while it stiffens the EOSes of pure nucleonic matter. Furthermore, the leptons and the hyperons have the similar influence on δ\delta meson effects. The δ\delta meson increases the maximum masses of neutron stars. The influence of (σ∗,ϕ)(\sigma^*,\phi) on the δ\delta meson effects are also investigated.Comment: 10 pages, 6 figures, 4 table

    Tensor coupling effects on spin symmetry in anti-Lambda spectrum of hypernuclei

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    The effects of ΛˉΛˉω\bar\Lambda\bar\Lambda\omega-tensor coupling on the spin symmetry of Λˉ\bar{\Lambda} spectra in Λˉ\bar{\Lambda}-nucleus systems have been studied with the relativistic mean-field theory. Taking 12^{12}C+Λˉ\bar{\Lambda} as an example, it is found that the tensor coupling enlarges the spin-orbit splittings of Λˉ\bar\Lambda by an order of magnitude although its effects on the wave functions of Λˉ\bar{\Lambda} are negligible. Similar conclusions has been observed in Λˉ\bar{\Lambda}-nucleus of different mass regions, including 16^{16}O+Λˉ\bar{\Lambda}, 40^{40}Ca+Λˉ\bar{\Lambda} and 208^{208}Pb+Λˉ\bar{\Lambda}. It indicates that the spin symmetry in anti-lambda-nucleus systems is still good irrespective of the tensor coupling.Comment: 12 pages, 3 figures

    The Drosophila caspase Ice is important for many apoptotic cell deaths and for spermatid individualization, a nonapoptotic process

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    Caspase family proteases play important roles in the regulation of apoptotic cell death. Initiator caspases are activated in response to death stimuli, and they transduce and amplify these signals by cleaving and thereby activating effector caspases. In Drosophila, the initiator caspase Nc (previously Dronc) cleaves and activates two short-prodomain caspases, Dcp-1 and Ice (previously Drice), suggesting these as candidate effectors of Nc killing activity. dcp-1-null mutants are healthy and possess few defects in normally occurring cell death. To explore roles for Ice in cell death, we generated and characterized an Ice null mutant. Animals lacking Ice show a number of defects in cell death, including those that occur during embryonic development, as well as during formation of adult eyes, arista and wings. Ice mutants exhibit subtle defects in the destruction of larval tissues, and do not prevent destruction of salivary glands during metamorphosis. Cells from Ice animals are also markedly resistant to several stresses, including X-irradiation and inhibition of protein synthesis. Mutations in Ice also suppress cell death that is induced by expression of Rpr, Wrinkled (previously Hid) and Grim. These observations demonstrate that Ice plays an important non-redundant role as a cell death effector. Finally, we demonstrate that Ice participates in, but is not absolutely required for, the non-apoptotic process of spermatid differentiation

    Clinical significance of serum lipids in idiopathic pulmonary alveolar proteinosis

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    <p>Abstract</p> <p>Background</p> <p>It is well known that pulmonary alveolar proteinosis(PAP) is characterised by accumulation of surfactant lipids and proteins within airspaces. However, few previous data describe the serum lipid levels associated with PAP.</p> <p>Materials and methods</p> <p>We retrospectively reviewed 25 patients with idiopathic PAP(iPAP). The serum lipid levels of patients with idiopathic PAP were compared with those of the healthy volunteers. In patients and healthy subjects, the LDL-C/HDL-C ratios were 2.94 ± 1.21 and 1.60 ± 0.70, respectively (<it>p </it>< 0.001), HDL-C were 1.11 ± 0.27 and 1.71 ± 0.71 respectively (<it>p </it>< 0.001). The values of LDL-C correlated significantly with those of PaO2 and P<sub>A-a</sub>O2 (r = -0.685, <it>p </it>= 0.003, and r = 0.688, <it>p </it>= 0.003, respectively). The values of LDL-C/HDL-C ratios also correlated with PaO2 levels and PA-aO2 levels (r = -0.698, p = 0.003, and r = 0.653, p = 0.006, respectively). 11 and 13 patients experienced respectively a decline in TC and LDL-C levels following whole lung lavage(WLL), the median decline was 0.71 mmol/L(<it>p </it>< 0.009) and 0.47 mmol/L(<it>p </it>< 0.003), respectively.</p> <p>Conclusions</p> <p>the serum lipid levels, especially the levels of LDL-C and LDL-C/HDL-C, may reflect the severity of the disease in PAP patients, and predict the therapeutic effect of WLL.</p

    Single nonmagnetic impurity resonance in FeSe-based 122-type superconductors as a probe for pairing symmetry

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    We study the effect of a single non-magnetic impurity in Ay_{y}Fe2−x_{2-x}Se2_{2} (A=K, Rb, or Cs) superconductors by considering various pairing states based on a three-orbital model consistent with the photoemission experiments. The local density of states on and near the impurity site has been calculated by solving the Bogoliubov-de Gennes equations self-consistently. The impurity-induced in-gap bound states are found only for attractive impurity scattering potential, as in the cases of doping of Co or Ni, which is characterized by the strong particle-hole asymmetry, in the nodeless dx2−y2d_{x^2-y^2} wave pairing state. This property may be used to probe the pairing symmetry of FeSe-based 122-type superconductors.Comment: 7 pages, 7 figure

    Generation of GHZ-type and \emph{W}-type entangled coherent states of three-cavity fields

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    We present experimental schemes to prepare the three-cavity GHZ-type and \emph{W}-type entangled coherent states in the context of dispersive cavity quantum electrodynamics. The schemes can be easily generalized to prepare the GHZ-type and \emph{W}-type entangled coherent states of nn-cavity fields. The discussion of our schemes indicates that it can be realized by current technologies.Comment: 4 pages, 2 figure

    Plaquette Ordering in SU(4) Antiferromagnets

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    We use fermion mean field theory to study possible plaquette ordering in the antiferromagnetic SU(4) Heisenberg model. We find the ground state for both the square and triangular lattices to be the disconnected plaquette state. Our mean field theory gives a first order transition for plaquette ordering for the triangular lattice. Our results suggest a large number of low lying states.Comment: 16 pages, 5 figure

    Dietary Total Antioxidant Capacity is Inversely Associated with Prostate Cancer Aggressiveness in a Population-Based Study

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    The purpose of this study was to determine the relationship between total antioxidant capacity (TAC) from diet and supplements and prostate cancer aggressiveness among 855 African Americans (AA) and 945 European Americans (EA) in the North Carolina-Louisiana Prostate Cancer Project (PCaP). Cases were classified as either high aggressive, low aggressive, or intermediate aggressive. TAC was calculated from the vitamin C equivalent antioxidant capacity of 42 antioxidants measured via food frequency questionnaire. EA reported greater dietary TAC from diet and supplements combined (P 1500 vs. < 500 mg VCE/d): 0.31 (95% CI: 0.15, 0.67; P-trend < 0.01), 0.28 (95% CI: 0.08, 0.96; P-trend < 0.001), and 0.36 (95% CI: 0.15, 0.86; P-trend = 0.58), respectively. These associations did not appear to differ between AA and EA. These data suggest that greater intake of antioxidants is associated with less aggressive prostate cancer. Additional research is needed to confirm these results and determine the underlying mechanisms
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