Search

José J Echevarria-Uraga,1 Ignacio García-Alonso,2 Fernando Plazaola,3 Maite Insausti,3 Néstor Etxebarria,3 Alberto Saiz-López,4 Begoña Fernández-Ruanova51Radiology Department, Hospital de Galdakao-Usánsolo, Bizkaia, Spain; 2Experimental Surgery Laboratory, Medicine Faculty, University of the Basque Country, Bizkaia, Spain; 3Faculty of Science and Technology, University of the Basque Country, Bizkaia, Spain; 4Pathology Department, Hospital de Galdakao-Usánsolo, Bizkaia, Spain; 5Osatek SA Unidad del Hospital de Galdakao-Usánsolo, Bizkaia, SpainPurpose: To evaluate, in an experimental model, the reliability of MRI for determining whether a higher iron concentration was obtained in tumor tissue than in normal liver parenchyma after intra-arterial administration of Fe3O4 lipophilic nanoparticles.Materials and methods: WAG/RijCrl rats were inoculated in the left hepatic lobe with 25,000 syngeneic CC-531 colon adenocarcinoma cells, after which they were randomized into two groups: control (CG) and infused (IG). After confirming tumor induction, the IG rats received intra-arterial suspensions of Fe3O4 nanoparticles (2.6 mg) in Lipiodol® (0.15 mL). To calculate the iron concentration, [Fe], in the tumor and liver tissues of both groups of rats, measurements of signal intensity from the tumors, healthy liver tissue, and paravertebral muscles were made on a 1.5T MRI system in gradient-echo DP* and T2*-weighted sequences. In addition, samples were collected to quantify the [Fe] by inductively coupled plasma-mass spectrometry (ICP-MS), as well as for histological analysis. Statistical analysis was performed with non-parametric tests, and Bland–Altman plots were produced; P values

Structures with infinite layers of transition metal and malonate ligand are observed in four new two-dimensional (MM'(C3H2O4)2(H2O)4) compounds. According to magnetic measurements, there is two-dimensional ferromagnetic coupling between the copper(II) ions in the copper compounds, and antiferromagnetic interactions for the manganese(II) compounds. Mixed metal oxides were obtained from their thermal treatments, at short reaction times and at temperatures lower than those of the traditional ceramic method.

The magnetic and magnetoresistive properties of Ln(sub0.7)Pb(sub0.3)Mn(sub1-x)FexO(sub3) are reported. They were prepared using the sol-gel low temperature method which results in smaller grains, producing high purity and homogenous powders. The structural, magnetic, and magnetoresistance measurements were compared, to provide a better understanding of the effects due to the presence of different lanthanide elements and the substitution of Mn by Fe ions.

The article presents a complete magnetic, as well as structural characterization of the different thiol capped ferromagnetic Ag nanoparticles. The nanoparticles even with similar sizes are shown to exhibit different magnetic behaviors.

Different dodecanethiol capped Au nanoparticles (NP) with similar sizes (∼2 nm) but different ferromagnetic signals at room temperature have been investigated by means of x-ray absorption spectroscopy at the Au L3-edge. The reversion of the x-ray magnetic circular dichroism signal with the change of sign of the external applied magnetic field confirms the location of the magnetism at the Au atoms. In comparison with the Au foil, all the samples present accentuated white lines at the x-ray absorption near-edge structure (XANES) indicating generation of 5d holes in the Au atoms located at surface of the NPs as consequence of a localized charge transfer from the Au surface atoms to the S atoms of the capping agent. XANES spectra reflect differences among the electronic structure of the Au NPs which are compared with the observed different macroscopic magnetic signals. [ABSTRACT FROM AUTHOR]