3,267 research outputs found

    Leptophilic dark matter in gauged U(1)LeLμU(1)_{L_e-L_\mu} model in light of DAMPE cosmic ray e++ee^+ + e^- excess

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    Motivated by the very recent cosmic-ray electron+positron excess observed by DAMPE collaboration, we investigate a Dirac fermion dark matter (DM) in the gauged LeLμL_e - L_\mu model. DM interacts with the electron and muon via the U(1)eμU(1)_{e-\mu} gauge boson ZZ^{'}. The model can explain the DAMPE data well. Although a non-zero DM-nucleon cross section is only generated at one loop level and there is a partial cancellation between ZeeZ^{'}ee and ZμμZ^{'}\mu\mu couplings, we find that a large portion of ZZ^{'} mass is ruled out from direct DM detection limit leaving the allowed ZZ^{'} mass to be close to two times of the DM mass. Implications for ppZ2pp \to Z^{'} \to 2\ell and pp2+Zpp \to 2\ell + Z^{'} , and muon g2g-2 anomaly are also studied.Comment: Discussions added, version accepted by EPJ

    Relationship among Self-appraisals, Others’ Actual Appraisals, and Reflected Appraisals on Primary School Teachers Teaching Ability

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    Convenient sampling and questionnaire survey was used to investigate the relationship among self-appraisals, others’ actual appraisals, and reflected appraisals on the teaching ability of 40 primary school teachers. The results of the study indicated that primary school teachers’ selfappraisals on teaching ability was obviously below others’ actual appraisals; generalized others had more influence on the self-appraisals of primary school teachers than specific others; primary school teachers’ reflected appraisals could influence their self-appraisals; and others’ actual appraisals could not directly influence self-appraisals. Consequently, we should pay more attention in developing the primary school teachers’ reflective ability, change the current way of teaching reflection, improve the influence of others’ actual appraisals on self-appraisals, and enhance the validity of teaching reflection

    Energy dependent chemical potentials of light hadrons and quarks based on transverse momentum spectra and yield ratios of negative to positive particles

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    We describe the transverse momentum (or mass) spectra of π±\pi^\pm, K±K^\pm, pp, and pˉ\bar{p} produced in central gold-gold (Au-Au), central lead-lead (Pb-Pb), and inelastic proton-proton (pppp) collisions at different collision energies range from the AGS to LHC by using a two-component (in most cases) Erlang distribution in the framework of multi-source thermal model. The fitting results are consistent with the experimental data and the energy-dependent chemical potentials of light hadrons (π\pi, KK, and pp) and quarks (uu, dd, and ss) in central Au-Au, central Pb-Pb, and inelastic pppp collisions from the yield ratios of negative to positive particles obtained from the normalization constants are then extracted. The study shows that most types of energy-dependent chemical potentials decrease with increase of collision energy over a range from the AGS to LHC. The curves of all types of energy-dependent chemical potentials, obtained from the linear fits of yield ratios vs energy, have inflection points at the same energy of 3.526 GeV, which is regarded as the critical energy of phase transition from a hadron liquid-like state to a quark gas-like state in the collision system and indicates that the hadronic interactions play an important role in this period. At the RHIC and LHC, all types of chemical potentials become small and tend to zero at very high energy, which confirms that the collision system possibly changes completely from the hadron-dominant liquid-like state to the quark-dominant gas-like state and the partonic interactions possibly play a dominant role at the LHC

    12β,14-Dihy­droxy-3-oxo-5β,20(22)-cardenolide monohydrate

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    The title compound, digoxigenone, C23H30O5·H2O, was biotransformed from digoxigenin. In the crystal, inter­molecular O—H⋯O hydrogen bonds contribute to the formation of a three-dimensional supra­molecular structure. The title compound has three fused six-membered rings (A,B,C) and two non-fused five-membered rings (D,E). As in other structures, compound nucleus has a cis-trans-cis conformation for the A-B,B-C,C-D ring junctions with rings A, B and C exhibiting chair conformations

    Infectomic Analysis of Gene Expression Profiles of Human Brain Microvascular Endothelial Cells Infected with Cryptococcus neoformans

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    In order to dissect the pathogenesis of Cryptococcus neoformans meningoencephalitis, a genomic survey of the changes in gene expression of human brain microvascular endothelial cells infected by C. neoformans was carried out in a time-course study. Principal component analysis (PCA) revealed significant fluctuations in the expression levels of different groups of genes during the pathogen-host interaction. Self-organizing map (SOM) analysis revealed that most genes were up- or downregulated 2 folds or more at least at one time point during the pathogen-host engagement. The microarray data were validated by Western blot analysis of a group of genes, including β-actin, Bcl-x, CD47, Bax, Bad, and Bcl-2. Hierarchical cluster profile showed that 61 out of 66 listed interferon genes were changed at least at one time point. Similarly, the active responses in expression of MHC genes were detected at all stages of the interaction. Taken together, our infectomic approaches suggest that the host cells significantly change the gene profiles and also actively participate in immunoregulations of the central nervous system (CNS) during C. neoformans infection

    Lipid raft/caveolae signaling is required for Cryptococcus neoformans invasion into human brain microvascular endothelial cells

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    <p>Abstract</p> <p>Background</p> <p><it>Cryptococcus neoformans </it>has a predilection for central nervous system infection. <it>C. neoformans </it>traversal of the blood brain barrier, composed of human brain microvascular endothelial cells (HBMEC), is the crucial step in brain infection. However, the molecular mechanism of the interaction between <it>Cryptococcus neoformans </it>and HBMEC, relevant to its brain invasion, is still largely unknown.</p> <p>Methods</p> <p>In this report, we explored several cellular and molecular events involving the membrane lipid rafts and caveolin-1 (Cav1) of HBMEC during <it>C. neoformans </it>infection. Immunofluorescence microscopy was used to examine the roles of Cav1. The knockdown of Cav1 by the siRNA treatment was performed. Phosphorylation of Cav1 relevant to its invasion functions was investigated.</p> <p>Results</p> <p>We found that the host receptor CD44 colocalized with Cav1 on the plasma membrane, and knockdown of Cav1 significantly reduced the fungal ability to invade HBMEC. Although the CD44 molecules were still present, HBMEC membrane organization was distorted by Cav1 knockdown. Concomitantly, knockdown of Cav1 significantly reduced the fungal crossing of the HBMEC monolayer <it>in vitro</it>. Upon <it>C. neoformans </it>engagement, host Cav1 was phosphorylated in a CD44-dependent manner. This phosphorylation was diminished by filipin, a disrupter of lipid raft structure. Furthermore, the phosphorylated Cav1 at the lipid raft migrated inward to the perinuclear localization. Interestingly, the phospho-Cav1 formed a thread-like structure and colocalized with actin filaments but not with the microtubule network.</p> <p>Conclusion</p> <p>These data support that <it>C. neoformans </it>internalization into HBMEC is a lipid raft/caveolae-dependent endocytic process where the actin cytoskeleton is involved, and the Cav1 plays an essential role in <it>C. neoformans </it>traversal of the blood-brain barrier.</p

    Relationships among Life quality, Social Support and Organizational Justice of White-collar Worker

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    Objective: To explore the relationship of white-collar workers’ life quality, social support and organizational justice. Methods: We used convenient sampling and questionnaire survey in the study. Totally 476 white-collar workers were from Chongqing Yongchuan by convenient sampling, they completed the whoqol-bref scale, perceived social support scale and organizational justice scale. Results: (1) The average score of white-collar workers’ life quality was (87.92±10.87), almost 90% white-collar workers’ felling of life quality and health was in the general level and above; marriage status、children status and monthly income could influence their life quality. (2)There is a significant correlation among white-collar workers’ life quality, social support and organizational justice. (3) Organizational justice has partial mediating effects on the relation of social support and life quality. Conclusion: White-collar workers’ life quality is in medium level, we should improve their life quality through increasing social support and organizational justice
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