1,927 research outputs found

    Dynamical Instability of Holographic QCD at Finite Density

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    In this paper we study the dynamical instability of Sakai-Sugimoto's holographic QCD model at finite baryon density. In this model, the baryon density, represented by the smeared instanton on the worldvolume of the probe D8-\overline{D8} mesonic brane, sources the worldvolume electric field, and through the Chern-Simons term it will induces the instability to form a chiral helical wave. This is similar to Deryagin-Grigoriev-Rubakov instability to form the chiral density wave for large N_c QCD at finite density. Our results show that this kind of instability occurs for sufficiently high baryon number densities. The phase diagram of holographic QCD will thus be changed from the one which is based only on thermodynamics. This holographic approach provides an effective way to study the phases of QCD at finite density, where the conventional perturbative QCD and lattice simulation fail.Comment: 18 pages, 6 figures;v2. add thermodynamics discussion; v4. Treatment of the instanton energy changed and QGP analysis added. Some figures replaced and added, including the phase diagra

    Doped holographic fermionic system

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    We construct a two-current model. It includes two gauge fields, which introduce the doping effect, and a neutral scalar field. And then we numerically construct an AdS black brane geometry with scalar hair. Over this background, we study the fermionic system with the pseudoscalar Yukawa coupling. Some universal properties from the pseudoscalar Yukawa coupling are revealed. In particular, as the coupling increases, there is a transfer of the spectral weight from the low energy band to the high energy band. The transfer is over low energy scales but not over all energy scales. The peculiar properties are also explored. The study shows that with the increase of the doping, the gap opens more difficult. It indicates that there is a competition between the pseudoscalar Yukawa coupling and the doping.Comment: 18 pages, 9 figure

    CR3 and Dectin-1 Collaborate in Macrophage Cytokine Response through Association on Lipid Rafts and Activation of Syk-JNK-AP-1 Pathway

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    Copyright: © 2015 Huang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited Acknowledgments We are grateful to the Second Core Laboratory of Research Core Facility at the National Taiwan University Hospital for confocal microscopy service and providing ultracentrifuge. We thank Dr. William E. Goldman (University of North Carolina, Chapel Hill, NC) for kindly providing WT and ags1-null mutant of H. capsulatum G186A. Funding: This work is supported by research grants 101-2320-B-002-030-MY3 from the Ministry of Science and Technology (http://www.most.gov.tw) and AS-101-TP-B06-3 from Academia Sinica (http://www.sinica.edu.tw) to BAWH. GDB is funded by research grant 102705 from Welcome Trust (http://www.wellcome.ac.uk). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

    Cloning, purification, and functional characterization of Carocin S2, a ribonuclease bacteriocin produced by Pectobacterium carotovorum

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    <p>Abstract</p> <p>Background</p> <p>Most isolates of <it>Pectobacterium carotovorum subsp. carotovorum </it>(Pcc) produce bacteriocins. In this study, we have determined that Pcc strain F-rif-18 has a chromosomal gene encoding the low-molecular-weight bacteriocin, Carocin S2, and that this bacteriocin inhibits the growth of a closely related strain. Carocin S2 is inducible by ultraviolet radiation but not by mutagenic agents such as mitomycin C.</p> <p>Results</p> <p>A carocin S2-defective mutant, TF1-2, was obtained by Tn5 insertional mutagenesis using F-rif-18. A 5706-bp DNA fragment was detected by Southern blotting, selected from a genomic DNA library, and cloned to the vector, pMS2KI. Two adjacent complete open reading frames within pMS2KI were sequenced, characterized, and identified as caroS2K and caroS2I, which respectively encode the killing protein and immunity protein. Notably, carocin S2 could be expressed not only in the mutant TF1-2 but also in <it>Escherichia coli </it>DH5α after entry of the plasmid pMS2KI. Furthermore, the C-terminal domain of CaroS2K was homologous to the nuclease domains of colicin D and klebicin D. Moreover, SDS-PAGE analysis showed that the relative mass of CaroS2K was 85 kDa and that of CaroS2I was 10 kDa.</p> <p>Conclusion</p> <p>This study shown that another nuclease type of bacteriocin was found in <it>Pectobacterium carotovorum</it>. This new type of bacteriocin, Carocin S2, has the ribonuclease activity of CaroS2K and the immunity protein activity of CaroS2I.</p

    Low-Dose Steroid Therapy Is Associated with Decreased IL-12 Production in PBMCs of Severe Septic Patients

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    Background. Sepsis-induced immunosuppression may result in higher mortality rates in patients. Methods. We examined the relationship of cytokine responses from stimulated peripheral blood mononuclear cells (PBMCs) and monocyte human leukocyte antigen-DR (HLA-DR) expression (days 1 and 7) with low-dose steroid therapy in 29 septic patients. Patients were treated according to the guidelines. Thirty healthy controls were enrolled for validation. Results. Eighteen patients were prescribed low-dose steroids and 11 were not. Interleukin- (IL-) 12 responses in patients without low-dose steroid therapy on days 1 and 7 were higher than those with low-dose steroid therapy. Compared to day 1, IL-12 responses significantly increased on day 7 in patients without low-dose steroid therapy. After regression analysis, the change in the IL-12 response from day 7 to day 1 was found to be independently associated with the low-dose steroid therapy. There was no difference in monocyte HLA-DR expression between patients treated with and without low-dose steroid on day 1 or 7. No change in monocyte HLA-DR expression from day 7 to day 1 was observed in patients with or without low-dose steroid therapy. Conclusion. Decreased IL-12 response was associated with the low-dose steroid therapy in PBMCs of septic patients

    Interleukin-17: A Promoter in Colorectal Cancer Progression

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    It is widely accepted that chronic inflammation plays an active role in cancer. Inflammatory immunocytes and related cytokines in the tumor microenvironment are supposed to be a “double-edged sword” in colorectal cancer (CRC) initiation and progression. Interleukin-17 (IL-17), a pleiotropic proinflammatory cytokine, can promote cancer-elicited inflammation and prevent cancer cells from immune surveillance. Despite controversy, IL-17 is generally considered to be a promoter in CRC progression. In this review, we devote to summarize the current progress regarding the role of IL-17 in tumor initiation and progression, as well as the prognostic value in CRC

    Fluctuations in Gene Regulatory Networks as Gaussian Colored Noise

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    The study of fluctuations in gene regulatory networks is extended to the case of Gaussian colored noise. Firstly, the solution of the corresponding Langevin equation with colored noise is expressed in terms of an Ito integral. Then, two important lemmas concerning the variance of an Ito integral and the covariance of two Ito integrals are shown. Based on the lemmas, we give the general formulae for the variances and covariance of molecular concentrations for a regulatory network near a stable equilibrium explicitly. Two examples, the gene auto-regulatory network and the toggle switch, are presented in details. In general, it is found that the finite correlation time of noise reduces the fluctuations and enhances the correlation between the fluctuations of the molecular components.Comment: 10 pages, 4 figure
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