145 research outputs found

    Magnetic properties of chain antiferromagnets RbFeSe<inf>2</inf>, TlFeSe<inf>2</inf>, and TlFeS<inf>2</inf>

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    © 2017, Allerton Press, Inc. Single crystals of ternary ion chalcogenides RbFeSe 2 , TlFeSe 2 , and TlFeS 2 are studied by X-ray diffraction, SQUID magnetometry, and Mössbauer spectroscopy. Common structural units of these chalcogenides are tetrahedra of FeCh 4 (chalcogen Ch = Se, S), arranged in chains by sharing an edge. It is found that RbFeSe 2 , TlFeSe 2 , and TlFeS 2 undergo transition to a collinear antiferromagnetic state below temperatures T N = 248, 290, and 196 K, respectively. Their magnetic moments are oriented perpendicular to the axes of the chains of FeCh 4 tetrahedra

    Magnetic Properties of Chain Antiferromagnets RbFeSe2, TlFeSe2, and TlFeS2

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    Single crystals of ternary ion chalcogenides RbFeSe2, TlFeSe2, and TlFeS2 are studied by X-ray diffraction, SQUID magnetometry, and Mossbauer spectroscopy. Common structural units of these chalcogenides are tetrahedra of FeCh4 (chalcogen Ch = Se, S), arranged in chains by sharing an edge. It is found that RbFeSe2, TlFeSe2, and TlFeS2 undergo transition to a collinear antiferromagnetic state below temperatures TN = 248, 290, and 196 K, respectively. Their magnetic moments are oriented perpendicular to the axes of the chains of FeCh4 tetrahedra

    Spatially, Temporally and Polarization-Resolved Photoluminescence Exploration of Excitons in Crystalline Phthalocyanine Thin Films

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    The lack of long range order in organic semiconductor thin films prevents the unveiling of the complete nature of excitons in optical experiments, because the diffraction limited beam diameters in the bandgap region far exceed typical crystalline grain sizes. Here we present spatially-, temporally- and polarization-resolved dual photoluminescence/linear dichroism microscopy experiments that investigate exciton states within a single crystalline grain in solution-processed phthalocyanine thin films. These experiments reveal the existence of a delocalized singlet exciton, polarized along the high mobility axis in this quasi-1D electronic system. The strong delocalized {\pi} orbitals overlap controlled by the molecular stacking along the high mobility axis is responsible for breaking the radiative recombination selection rules. Using our linear dichroism scanning microscopy setup we further established a rotation of molecules (i.e. a structural phase transition) that occurs above 100 K prevents the observation of this exciton at room temperature.Comment: submitted to Journal of Chem Phys letter

    The cytotoxic T cell proteome and its shaping by the kinase mTOR

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    High-resolution mass spectrometry maps the cytotoxic T lymphocyte (CTL) proteome and the impact of mammalian target of rapamycin complex 1 (mTORC1) on CTLs. The CTL proteome was dominated by metabolic regulators and granzymes and mTORC1 selectively repressed and promoted expression of subset of CTL proteins (~10%). These included key CTL effector molecules, signaling proteins and a subset of metabolic enzymes. Proteomic data highlighted the potential for mTORC1 negative control of phosphatidylinositol (3,4,5)-trisphosphate (PtdIns(3,4,5)P(3)) production in CTL. mTORC1 was shown to repress PtdIns(3,4,5)P(3) production and to determine the mTORC2 requirement for activation of the kinase Akt. Unbiased proteomic analysis thus provides a comprehensive understanding of CTL identity and mTORC1 control of CTL function

    2019 ESC/EAS guidelines for the management of dyslipidaemias : Lipid modification to reduce cardiovascular risk

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    Correction: Volume: 292 Pages: 160-162 DOI: 10.1016/j.atherosclerosis.2019.11.020 Published: JAN 2020Peer reviewe

    Stability of EG cylindrical shells with shear stresses on a Pasternak foundation

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    This article is the result of an investigation on the influence of a Pasternak elastic foundation on the stability of exponentially graded (EG) cylindrical shells under hydrostatic pressure, based on the first-order shear deformation theory (FOSDT) considering the shear stresses. The shear stresses shape function is distributed parabolic manner through the shell thickness. The governing equations of EG orthotropic cylindrical shells resting on the Pasternak elastic foundation on the basis of FOSDT are derived in the framework of Donnell-type shell theory. The novelty of present work is to achieve closed-form solutions for critical hydrostatic pressures of EG orthotropic cylindrical shells resting on Pasternak elastic foundation based on FOSDT. The expressions for critical hydrostatic pressures of EG orthotropic cylindrical shells with and without an elastic foundation based on CST are obtained, in special cases. Finally, the effects of Pasternak foundation, shear stresses, orthotropy and heterogeneity on critical hydrostatic pressures, based on FOSDT are investigated
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