Exploring ferroelectric and magnetic properties of Tb-substituted m = 5 layered Aurivillius phase thin films

Here, we report the effect of A-site substitution of Tb at the expense of Bi on the ferroelectric and magnetic properties in m = 5 layered 2-D Aurivillius Bi6Ti3Fe2O18 thin films. The nominal stoichiometry of the prepared compound is Tb0.40Bi5.6Fe2Ti3O18, Tb0.90Bi5.1Fe2Ti3O18, and Bi6Ti3Fe2O18. Phase examination reveals that only 0.40 mol. % is successfully substituted forming Tb0.40Bi5.6Fe2Ti3O18 thin films. Lateral and vertical piezoresponse switching loops up to 200 °C reveal responses for Bi6Ti3Fe2O18, Tb substituted Tb0.40Bi5.6Fe2Ti3O18, and Tb0.90Bi5.1Fe2Ti3O18 thin films along the in-plane (±42.31 pm/V, 88 pm/V and ±134 pm/V, respectively) compared with the out-of-plane (±6.15 pm/V, 19.83 pm/V and ±37.52 pm/V, respectively). The macroscopic in-plane polarization loops reveal in-plane saturation (Ps) and remanence polarization (Pr) for Bi6Ti3Fe2O18 of ±26.16 μC/cm2 and ±22 μC/cm2, whereas, ±32.75 μC/cm2 and ±22.11 μC/cm2, ±40.30 μC/cm2 and ±28.5 μC/cm2 for Tb0.40Bi5.6Fe2Ti3O18 and Tb0.90Bi5.1Fe2Ti3O18 thin films, respectively. No ferromagnetic signatures were observed for Bi6Ti3Fe2O18 and Tb0.40Bi5.6Fe2Ti3O18. However, a weak response was observed for the Tb0.90Bi5.1Fe2Ti3O18 at 2 K. Microstructural analysis of Tb0.90Bi5.1Fe2Ti3O18 revealed that it contains 4 vol. % Fe:Tb rich areas forming FexTbyOz, which accounts for the observed magnetic moment. This study demonstrates the importance of thorough microstructural analysis when determining whether magnetic signatures can be reliably assigned to the single-phase system. We conclude that Tb0.40Bi5.6Fe2Ti3O18 and Tb0.90Bi5.1Fe2Ti3O18 samples are not multiferroic but demonstrate the potential for Fe-RAM applications

The PPAR alpha and PPAR gamma Epigenetic Landscape in Cancer and Immune and Metabolic Disorders

Peroxisome proliferator-activated receptors (PPARs) are ligand-modulated nuclear receptors that play pivotal roles in nutrient sensing, metabolism, and lipid-related processes. Correct control of their target genes requires tight regulation of the expression of different PPAR isoforms in each tissue, and the dysregulation of PPAR-dependent transcriptional programs is linked to disorders, such as metabolic and immune diseases or cancer. Several PPAR regulators and PPAR-regulated factors are epigenetic effectors, including non-coding RNAs, epigenetic enzymes, histone modifiers, and DNA methyltransferases. In this review, we examine advances in PPARα and PPARγ-related epigenetic regulation in metabolic disorders, including obesity and diabetes, immune disorders, such as sclerosis and lupus, and a variety of cancers, providing new insights into the possible therapeutic exploitation of PPAR epigenetic modulation.This research was funded by the Ministerio de Ciencia, Innovacion y Universidades (MCNU) (SAF2017-90604-REDT-NurCaMeIn, RTI2018-095928-BI00) and the Comunidad de Madrid (MOIR-B2017/BMD-3684) to MR; the MCNU fellowships to JP (FPU17/01731) and to JM-M (PRE2019-087964). The CNIC is supported by the MCNU and the Pro CNIC Foundation.S

Flow Cytometry Has a Significant Impact on the Cellular Metabolome

The characterization of specialized cell subpopulations in a heterogeneous tissue is essential for understanding organ function in health and disease. A popular method of cell isolation is fluorescence-activated cell sorting (FACS) based on probes that bind surface or intracellular markers. In this study, we analyze the impact of FACS on the cell metabolome of mouse peritoneal macrophages. Compared with directly pelleted macrophages, FACS-treated cells had an altered content of metabolites related to the plasma membrane, activating a mechanosensory signaling cascade causing inflammation-like stress. The procedure also triggered alterations related to energy consumption and cell damage. The observed changes mostly derive from the physical impact on cells during their passage through the instrument. These findings provide evidence of FACS-induced biochemical changes, which should be taken into account in the design of robust metabolic assays of cells separated by flow cytometry.FJ.R., J.G., and D.R. acknowledge funding from the Ministerio de Economia y Competitividad (CTQ2014-55279-R). This study was also supported by Ministerio de Economia y Competitividad grant BIO2015-67580-P through the Carlos III Institute of Health (ISCIII) and the Fundacion La Marato TV3 to J.V and to M.R (201605-30-31-32). J.V. laboratory is a member of Proteored, PRB3 and is supported by grant PT17/0019, of the PE I+D+i 2013-2016, funded by ISCIII and European Regional Development Fund (ERDF). M.R. received grants from the Ministerio de Economia y Competitividad (SAF2015-64287R, SAF2017-90604-REDT). J.V and M.R received funding from the People Programme (Marie Curie Actions) of the European Union Seventh Framework Programme (FP7/2007-2013) under REA grant agreement no 608027 (CardioNext Initial Training Networks project). A.B. is a FP7-PEOPLE-2013-ITN-Cardionext fellow. The CNIC is supported by the Ministerio de Ciencia, Innovacion y Universidades (MCNU) and the Pro-CNIC Foundation, and is a Severo Ochoa Center of Excellence (SEV-2015-0505).S

Photochemical solution deposition of beta-Bi2O3 thin films

International audienceThe non-equilibrium beta-Bi2O3 polymorph is stabilized in thin films by a photochemical synthesis method. A strong ultraviolet-absorbing bismuth(III)-N-methyldiethanolamine complex is synthesized in solution as an ideal precursor for the beta-Bi2O3 phase. Ultraviolet-light induces the formation of an amorphous -Bi-O-Bi- continuous network in the films deposited from the former solution that easily converts into the beta-Bi2O3 polymorph at a temperature as low as 250 A degrees C. The room temperature stabilization of the beta-Bi2O3 phase is confirmed by their structural characterization using four-circle X-ray diffractometry. This study unequivocally identified the tetragonal crystal structure of the beta-Bi2O3 polymorph in the films. The high phase purity of these beta-Bi2O3 films is responsible for their exceptional visible-light photocatalytic activity, thus enabling the applications of the films of this metastable phase at room-temperature conditions

Photochemical solution deposition of beta-Bi2O3 thin films

International audienceThe non-equilibrium beta-Bi2O3 polymorph is stabilized in thin films by a photochemical synthesis method. A strong ultraviolet-absorbing bismuth(III)-N-methyldiethanolamine complex is synthesized in solution as an ideal precursor for the beta-Bi2O3 phase. Ultraviolet-light induces the formation of an amorphous -Bi-O-Bi- continuous network in the films deposited from the former solution that easily converts into the beta-Bi2O3 polymorph at a temperature as low as 250 A degrees C. The room temperature stabilization of the beta-Bi2O3 phase is confirmed by their structural characterization using four-circle X-ray diffractometry. This study unequivocally identified the tetragonal crystal structure of the beta-Bi2O3 polymorph in the films. The high phase purity of these beta-Bi2O3 films is responsible for their exceptional visible-light photocatalytic activity, thus enabling the applications of the films of this metastable phase at room-temperature conditions