17 research outputs found

    Magnetism of the spin-trimer compound CaNi<sub>3</sub>(P<sub>2</sub>O<sub>7</sub>)<sub>2</sub>: Microscopic insight from combined <sup>31</sup>P NMR and first-principles studies

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    Magnetization, P-31 nuclear magnetic resonance study, and first-principles electronic structure calculations have been performed in the spin-1 trimer chain compound CaNi3(P2O7)(2). Two separate spectra arising from magnetically and crystallographically inequivalent P sites are observed. In the ordered state, the resonance lines for both the P sites (P1 and P2) are found to be split into two, which is clear microscopic evidence of the development of two-sublattice AFM order below T-M. A nonnegligible contribution of ferromagnetic hyperfine field and dipolar field have also been seen in the ordered state. The first-principles calculations show that the intratrimer (J(1)) and intertrimer interactions (J(2)) are of weak ferromagnetic type with the values 2.85 and 1.49 meV, respectively, whereas the interchain interaction (J(3)) is of strong antiferromagnetic type with a value of 5.63 meV. The anisotropy of the imaginary part of dynamical spin susceptibility around T-M along with the exponential decrement of 1/T-1 below T-M indicate the probable participation of the Ni-3d electron's orbital degrees of freedom in the ferrimagnetic transition. The dominance of orbital fluctuations over the spin fluctuations seems to be responsible for showing low value of the binding energy u of the local spin configuration (estimated from local spin models) and an unusually weak exponent in the power-law behavior of 1/T-1 below 50 K, in the paramagnetic state. Electronic structure calculations also reveal the importance of orbital degrees of freedom of Ni-3d moments, which is consistent with our NMR data analysis

    First experimental evidences on the ferroelectric nature of struvite

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    Struvite (MgNH4PO4·6H2O) is a mineral first identified in 1845. It is tested for several reasons: (1) it is a problem in liquid wastewater treatment plants; (2) on the other hand, it is recovered from this wastewater because of phosphorus, magnesium, and nitrogen; (3) it is the main component of infectious urinary stones. In this paper, we present the first experimental evidences of the ferroelectric nature of struvite at room temperature. Struvite shows a hysteresis loop and spontaneous electric polarization that can be reversed by an application of an external electric field. The measured value of residual polarization of struvite is equal to 0.95 μC/cm2. We also report observations of the ferroelectric domains in struvite using birefringence imaging technique. The non-centrosymmetry of the crystal lattice is confirmed with the use of the Kurtz–Perry powder test. The second harmonic generation response for struvite in relation to that of potassium dihydrogen phosphate is 0.36. We suggest that ferroelectric properties for struvite, in particular, spontaneous polarization, can have a significant impact on the behavior of struvite in aqueous solutions, such as liquid wastewater or urine

    Cytokines and growth factors

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    Several cytokines have been used to treat autoimmune diseases, viral infections, and cancer and to regenerate the skin. In particular, interferons (INFs) have been used to treat cancer, hepatitis B and C, and multiple sclerosis, while interleukins (ILs) and tumor necrosis factors (TNFs) have been used in the management of different types of cancer. Concerning the hematopoietic growth factors (HGFs), epoetin has been used for anemia, whereas the colony-stimulating factors (CSFs) have been used for neutropenia. Other growth factors have been extensively explored, although most still need to demonstrate in vivo clinical relevance before reaching the market.This chapter provides an overview on the therapeutic applications of biological medicines containing recombinant cytokines and growth factors (HGFs and others). From this review, we concluded that the clinical relevance of recombinant cytokines has been increasing. Since the 1980s, the European Medicines Agency (EMA) and/or Food and Drug Administration (FDA) have approved 89 biological medicines containing recombinant cytokines. Among these, 18 were withdrawn, 24 are biosimilars, and 18 are orphans.So far, considerable progress has been made in discovering new cytokines, additional cytokine functions, and how they interfere with human diseases. Future prospects include the approval of more biological and biosimilar medicines for different therapeutic applications.info:eu-repo/semantics/publishedVersio
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