68 research outputs found

    Protective Effects of White Button Mushroom (Agaricus bisporus) against Hepatic Steatosis in Ovariectomized Mice as a Model of Postmenopausal Women

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    Nonalcoholic fatty liver disease (NAFLD) includes various hepatic pathologies ranging from hepatic steatosis to non-alcoholic steatohepatitis (NASH), fibrosis and cirrhosis. Estrogen provides a protective effect on the development of NAFLD in women. Therefore, postmenopausal women have a higher risk of developing NAFLD. Hepatic steatosis is an early stage of fatty liver disease. Steatosis can develop to the aggressive stages (nonalcoholic steatohepatitis, fibrosis and cirrhosis). Currently, there is no specific drug to prevent/treat these liver diseases. In this study, we found that white button mushroom (WBM), Agaricus Bisporus, has protective effects against liver steatosis in ovariectomized (OVX) mice (a model of postmenopausal women). OVX mice were fed a high fat diet supplemented with WBM powder. We found that dietary WBM intake significantly lowered liver weight and hepatic injury markers in OVX mice. Pathological examination of liver tissue showed less fat accumulation in the livers of mice on WBM diet; moreover, these animals had improved glucose clearance ability. Microarray analysis revealed that genes related to the fatty acid biosynthesis pathway, particularly the genes for fatty acid synthetase (Fas) and fatty acid elongase 6 (Elovl6), were down-regulated in the liver of mushroom-fed mice. In vitro mechanistic studies using the HepG2 cell line showed that down-regulation of the expression of FAS and ELOVL6 by WBM extract was through inhibition of Liver X receptor (LXR) signaling and its downstream transcriptional factor SREBP1c. These results suggest that WBM is protective against hepatic steatosis and NAFLD in OVX mice as a model for postmenopausal women

    Dielectric characterization of multiferroic magnetoelectric double-perovskite Y(Ni0.5Mn0.5)O3 thin films

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    We report on the functional properties of the Y(Ni0.5Mn0.5)O3 epitaxial thin films, growth by pulsed laser deposition, observing the clear features of their ferroelectric and ferromagnetic nature at cryogenic temperature. The characterization of temperature-dependent complex impedance spectroscopy has shown a dielectric anomaly around the ferromagnetic Curie temperature (100 K) indicative of coupling between magnetic and electric orders.The financial support by the Ministerio de Ciencia e Innovacion of the Spanish Government (Grant No. BES-2009-028641 and Project Nos. MAT2011-29269-C03-03, NANOSELECT, MAT2014-56063-C2-2-R, CSD2007-00041, MAT2015-73839-JIN, and IMAGINE CSD2009-00013) and Generalitat de Catalunya (2014 SGR 734) is acknowledged. E.C. would like to thank the National Science Centre of Poland under the PRELUDIUM (UMO-2015/17/N/ST5/ 01988) for financial support. I.F. acknowledges the financial support from the Spanish Ministry of Economy and Competitiveness, through the “Severo Ochoa” Programme for Centres of Excellence in R&D (SEV-2015-0496), and also the Juan de la Cierva–Incorporacion postdoctoral fellowship (IJCI- 2014-19102) from the Spanish Ministry of Economy and Competitiveness of Spanish Government.Peer reviewe

    High-temperature magnetodielectric Bi(Fe0.5Mn0.5)O3 thin films with checkerboard-ordered oxygen vacancies and low magnetic damping

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    The possibility of affecting the magnetic properties of a material by dielectric means, and vice versa, remains an attractive perspective for modern electronics and spintronics. Here, we report on epitaxial Bi(Fe0.5Mn0.5)O3 thin films with exceptionally low Gilbert damping and magnetoelectric coupling above room temperature (<400 K). The ferromagnetic order, not observed in bulk, has been detected with a total magnetization of 0.44 μB/formula units with low Gilbert damping parameter (0.0034), both at room temperature. Additionally, a previously overlooked check-board ordering of oxygen vacancies is observed, providing insights on the magnetic and dielectric origin of the multifunctional properties of the films. Finally, intrinsic magnetodielectric behavior is observed as revealed by the variation of dielectric permittivity well above room temperature. These findings show the possibility of electric-field-controlled magnetic properties, in low Gilbert-damping-based spintronic devices, using single-phase multiferroic material

    Dielectric characterization of multiferroic magnetoelectric double-perovskite Y(Ni0.5Mn0.5)O3 thin films

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    We report on functional properties of Y(Ni0.5Mn0.5)O3 epitaxial thin films, growth by pulsed laser deposition, observing clear features of its ferroelectric and ferromagnetic nature at cryogenic temperature. Temperature-dependent complex impedance spectroscopy (IS) characterization has shown a dielectric anomaly around the ferromagnetic Curie temperature ( 100 K) indicative of coupling between magnetic and electric orders

    Bone marrow niche trafficking of miR-126 controls the self-renewal of leukemia stem cells in chronic myelogenous leukemia

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    Leukemia stem cells (LSCs) in individuals with chronic myelogenous leukemia (CML) (hereafter referred to as CML LSCs) are responsible for initiating and maintaining clonal hematopoiesis. These cells persist in the bone marrow (BM) despite effective inhibition of BCR–ABL kinase activity by tyrosine kinase inhibitors (TKIs). Here we show that although the microRNA (miRNA) miR-126 supported the quiescence, self-renewal and engraftment capacity of CML LSCs, miR-126 levels were lower in CML LSCs than in long-term hematopoietic stem cells (LT-HSCs) from healthy individuals. Downregulation of miR-126 levels in CML LSCs was due to phosphorylation of Sprouty-related EVH1-domain-containing 1 (SPRED1) by BCR–ABL, which led to inhibition of the RAN–exportin-5–RCC1 complex that mediates miRNA maturation. Endothelial cells (ECs) in the BM supply miR-126 to CML LSCs to support quiescence and leukemia growth, as shown using mouse models of CML in which Mir126a (encoding miR-126) was conditionally knocked out in ECs and/or LSCs. Inhibition of BCR–ABL by TKI treatment caused an undesired increase in endogenous miR-126 levels, which enhanced LSC quiescence and persistence. Mir126a knockout in LSCs and/or ECs, or treatment with a miR-126 inhibitor that targets miR-126 expression in both LSCs and ECs, enhanced the in vivo anti-leukemic effects of TKI treatment and strongly diminished LSC leukemia-initiating capacity, providing a new strategy for the elimination of LSCs in individuals with CML

    Optical and semiconductive properties of binary and ternary thin films from the Nb-Ti-O system

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    A study has been conducted based on the Mott-Schottky model acquisition by potentiodynamic electrochemical impedance spectroscopy, to determine the physical-chemical properties of binary TiO2, Nb2O5 and ternary Nb-Ti-O thin films (semiconductor type) based on Nb,Ti, O elements. The technique used for the study of optical properties was that of spectral transmittance, measurements were performed using a spectrophotometer. The consistency of the impedance data has been studied by calculating the Kramers-Kronig relations. The structural properties were analyzed by XRD patterns; the chemical composition measurements for all thin films were made by using XPS technique. So, in this research the transmittance values change from 72.74% for Nb2O5 to 59.68% for Ti-Nb-O with wavelength around 355 nm. The absorption coefficients for all films were analyzed from 31823.87 cm−1 for Nb2O5 to 91240.90 cm−1 for Nb-Ti-O with wavelength around 355 nm evidencing thus a 65% reduction. The direct band gap it was found that the photon energy (band gap Eg) changes in all films from 3.56 eV for Nb2O5 to 3.96 eV for Ti-Nb-O evidencing a 10% reduction. The extinction coefficient values change in all films from 0.038 cm−1 for Nb2O5 to 0.277 cm−1 for Ti-Nb-O films with wavelength around 355 nm, exhibiting an 86% increasing. Finally, it was observed by the Mott-Schottky analysis that the reference potential (Ag/AgCl) changes for all films from −2.09 V for Nb2O5 to −0.80 V for Ti-Nb-O material showing a 62% reduction. Keywords: Mott-Schottky, Thin films, Titanium oxide, Niobium oxide, Semiconductor propertie

    Combined reactive/non-reactive DC magnetron sputtering of high temperature composite AlN–TiB2–TiSi2

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    High temperature composite target AlN–TiB2–TiSi2 with heterogeneous distribution of compounds (AlN—50 wt.%; TiB2—35 wt.%; TiSi2—15 wt.%) is used for sputtering via combined reactive/non-reactive DC magnetron sputtering onto substrate materials either cylindrical polished steel (Fe, 18%—Ni, 12%—Cr, 10%—Ti) 3 mm diameter or monocrystalline silicon. The gradient coating has been produced by sequential non-reactive and reactive sputtering of the target. The structural and morphological properties of the deposited films are analyzed by transmission electron microscopy, scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy. The tribo-mechanical properties are studied by means of nanoindentation and nanowear tests. The gradient film is composed of two layers with different microstructure and elemental composition. The first layer with thickness ~200 nm is mainly based on light B, C and N as well metal elements Al, Si and Ti. The presence of very well distributed nanocrystals embedded in an amorphous matrix, with crystal sizes ranging from 5 to 40 nm is observed in the second layer ~700 nm thickness and composed of Al, Ti, Si, B, and N. Films show very flat surfaces, with roughness around 0.35 nm. The hardness, elastic modulus, elastic recovery (We), H/E⁎ ratio and H3 /E⁎2 ratio are determined as 17.55 GPa, 216.7 GPa, 60%, 0.08 and 0.12 GPa, respectively. Nanowear tests demonstrate relatively high wear resistance of the coatings. Samples show promising characteristics for hard protective adaptive coatings and diffusion barriers due to short propagation of dislocations in the amorphous matrix and the elastic and hard nature of the nanocomposite structure

    Near infrared photolysis of a Ru polypyridyl complex by upconverting nanoparticles

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    NaYF4:Yb3+/Er3+nanocrystals upconvert near infrared light (980 nm) into higher energy visible photons capable of effecting the photodissociation of the monodentate pyridyl ligand in cis-[Ru(bpy)2(py)2]Cl2: opening an opportunity for advancing the use of photoactivatable metal complexes in medicine and biology
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