ABSTRACT
A cubic quadruple perovskite oxide CeMn3Cr4O12 has been synthesized under high-pressure and high-temperature conditions of 8 GPa and 1273 K. The X-ray absorption spectroscopy reveals that the Ce ions are in a trivalent state, as represented by the ionic model of Ce3+Mn3+3Cr3+4O12. The magnetic study demonstrates three independent antiferromagnetic transitions attributed to Ce (â¼10 K), Mn (46 K), and Cr (133 K) ions. Furthermore, a magnetic field-induced antiferromagnetic-to-ferromagnetic (metamagnetic) transition of Ce3+ 4f moments is observed at low temperatures below 20 K, exhibiting a rare example of metamagnetism in the Ce3+-oxides. This finding represents that the 3d-electron magnetic sublattices play a role in the metamagnetism of 4f-electron magnetic moments, demonstrating a new aspect of the 3d-4f complex electron systems.
ABSTRACT
The presented research aims to verify whether physicochemical properties of lung fibroblasts, modified by substrate stiffness, can be used to discriminate between normal and fibrotic cells from idiopathic pulmonary fibrosis (IPF). The impact of polydimethylsiloxane (PDMS) substrate stiffness on the physicochemical properties of normal (LL24) and IPF-derived lung fibroblasts (LL97A) was examined in detail. The growth and elasticity of cells were assessed using fluorescence microscopy and atomic force microscopy working in force spectroscopy mode, respectively. The number of fibroblasts, as well as their shape and the arrangement, strongly depends on the mechanical properties of the substrate. Moreover, normal fibroblasts remain more rigid as compared to their fibrotic counterparts, which may indicate the impairments of IPF-derived fibroblasts induced by the fibrosis process. The chemical properties of normal and IPF-derived lung fibroblasts inspected using time-of-flight secondary ion mass spectrometry, and analyzed complexly with principal component analysis (PCA), show a significant difference in the distribution of cholesterol and phospholipids. Based on the observed distinctions between healthy and fibrotic cells, the mechanical properties of cells may serve as prospective diagnostic biomarkers enabling fast and reliable identification of idiopathic pulmonary fibrosis (IPF).
