57 research outputs found

    Macrophage signaling in HIV-1 infection

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    The human immunodeficiency virus-1 (HIV-1) is a member of the lentivirus genus. The virus does not rely exclusively on the host cell machinery, but also on viral proteins that act as molecular switches during the viral life cycle which play significant functions in viral pathogenesis, notably by modulating cell signaling. The role of HIV-1 proteins (Nef, Tat, Vpr, and gp120) in modulating macrophage signaling has been recently unveiled. Accessory, regulatory, and structural HIV-1 proteins interact with signaling pathways in infected macrophages. In addition, exogenous Nef, Tat, Vpr, and gp120 proteins have been detected in the serum of HIV-1 infected patients. Possibly, these proteins are released by infected/apoptotic cells. Exogenous accessory regulatory HIV-1 proteins are able to enter macrophages and modulate cellular machineries including those that affect viral transcription. Furthermore HIV-1 proteins, e.g., gp120, may exert their effects by interacting with cell surface membrane receptors, especially chemokine co-receptors. By activating the signaling pathways such as NF-kappaB, MAP kinase (MAPK) and JAK/STAT, HIV-1 proteins promote viral replication by stimulating transcription from the long terminal repeat (LTR) in infected macrophages; they are also involved in macrophage-mediated bystander T cell apoptosis. The role of HIV-1 proteins in the modulation of macrophage signaling will be discussed in regard to the formation of viral reservoirs and macrophage-mediated T cell apoptosis during HIV-1 infection

    High temperature magnetic susceptibility of Hg1-xFexSe

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    Magnetic susceptibility of diluted magnetic semiconductor Hg1-xFexSe (x = 0.04, 0.08, 0.11) has been measured in the temperature range 50-300 K. Observed temperature dependence above 90 K is analyzed in terms of the high temperature expansion of the magnetic susceptibility developed for Fe-type diluted magnetic semiconductors. The nearest neighbour exchange constant is estimated as J(NN)/k(B) = (-11 +/- 3) K. At higher temperatures, considerable deviation of the magnetic susceptibility from the Curie-Weiss law is detected. (C) 1997 Elsevier Science Ltd

    Susceptibility of the Rare Earth Ternary RNiSi2\text{}_{2} and RNiGe2\text{}_{2} Compounds

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    The ternary silicides and germanides RNiX2\text{}_{2} (R - rare earth, X = Si or Ge) with the orthorhombic CeNiSi2\text{}_{2}-type structure are investigated by magnetometric measurements. CeNiSi2\text{}_{2}, CeNiGe2\text{}_{2} and SmNiGe2\text{}_{2} have a nonmagnetic state in low temperatures. The compounds with R = Pr and Nd are ferromagnets while those containing R = Gd-Er are antiferromagnets. The de Gennes scaling of the Néel temperatures indicates a strong influence of the crystalline-electric field effects

    Magnetic structure of Tb3Cu4Si4

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    Magneto-optical study of the zero-field splitting in a mononuclear tetrahedrally coordinated Co(II) compound with a mixed ligand surrounding

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    The new mononuclear [Co(dbz)Cl-2] (dbz = bis(2-benzimidazolyl)ethane) complex has been studied by magnetic measurements and variable-temperature, variable-field magnetic circular dichroism (MCD) spectroscopy, accompanied by theoretical modelling. The values of the zero-field splitting parameters obtained from different experimental techniques are compared with the quantum-chemical calculations. (C) 2020 Elsevier Ltd. All rights reserved.Metals in Catalysis, Biomimetics & Inorganic Material
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