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We present an investigation of a nanostructured Fe-Al-O system with x = Al/Al + Fe ratios of 0.17, 0.33 and 0.50, prepared by the autocombustion method. The main phase found in all samples is the cubic spinel phase. The inclusion of Al in the spinel structure resulted in a progressive decrease in both the cell parameter and the grain size, with the former approaching the cell parameter of maghemite rather than magnetite. Although the XRD patterns match those reported for AlFe2O4, Mössbauer spectroscopy and magnetic measurements allows us to determine that the formed spinel phase can be identified as Al-doped maghemite-like Fe2-yAlyO3. The room temperature Mössbauer spectrum of sample x = 0.17 consists of magnetic components belonging to iron at the iron (III) oxide spinel sites, plus a central doublet. For higher Al content, the relative area of the magnetic components decreases, and the spectra mainly consists of a Fe3+ broad doublet corresponding to superparamagnetic iron (III) oxide particles. The 13 K spectrum of x = 0.33 sample (nominally AlFe2O4) is mainly composed of magnetic sites belonging to blocked particle moments of Al-doped maghemite-like particles. The magnetization loops are consistent with a ferro/ferrimagnetic behaviour, whose saturation magnetization decreases with the incorporation of Al. [ABSTRACT FROM AUTHOR]

We present an investigation of a nanostructured Fe-Al-O system with x = Al/Al + Fe ratios of 0.17, 0.33 and 0.50, prepared by the autocombustion method. The main phase found in all samples is the cubic spinel phase. The inclusion of Al in the spinel structure resulted in a progressive decrease in both the cell parameter and the grain size, with the former approaching the cell parameter of maghemite rather than magnetite. Although the XRD patterns match those reported for AlFe2O4, Mössbauer spectroscopy and magnetic measurements allows us to determine that the formed spinel phase can be identified as Al-doped maghemite-like Fe2-yAlyO3. The room temperature Mössbauer spectrum of sample x = 0.17 consists of magnetic components belonging to iron at the iron (III) oxide spinel sites, plus a central doublet. For higher Al content, the relative area of the magnetic components decreases, and the spectra mainly consists of a Fe3+ broad doublet corresponding to superparamagnetic iron (III) oxide particles. The 13 K spectrum of x = 0.33 sample (nominally AlFe2O4) is mainly composed of magnetic sites belonging to blocked particle moments of Al-doped maghemite-like particles. The magnetization loops are consistent with a ferro/ferrimagnetic behaviour, whose saturation magnetization decreases with the incorporation of Al. [ABSTRACT FROM AUTHOR]

We present a combined Mössbauer and ab initio study on the influence of oxygen-vacancies on the hyperfine and magnetic properties of the ZnFe O spinel ferrite. Samples with different degree of oxygen-vacancies were obtained from zinc ferrite powder that was thermally treated at different temperatures up to 650 C under vacuum.Theoretical calculations of the hyperfine parameters, magnetic moments and magnetic alignment have been carried out considering different defects such as oxygen vacancies and cation inversion. We show how theoretical and experimental approaches are complementary to characterize the local structure around Fe atoms and interpret the observed changes in the hyperfine parameters as the level of defects increases. [ABSTRACT FROM AUTHOR]

Samples of Sn0.90Fe0.10O2 were prepared by mechanosynthesis method. The structure and magnetic behavior of the samples have been investigated by X-ray diffraction (XRD) and Mössbauer spectroscopy. It has been found that for short milling times a small percentage of the initial hematite remains simultaneously with the formation of metallic Fe. Additionally a paramagnetic contribution appears in the Mössbauer spectra. For milling times, over 2 h, the iron ions are in paramagnetic states having +3 and +2 oxidation states while by XRD only the rutile structure diffraction lines were observed. [ABSTRACT FROM AUTHOR]

Commercial LaAlO3 substrates were thermally cycled simulating a procedure similar to those followed during TiO2 and SnO2 dilute magnetic semiconductors’ film pulsed laser deposition. Ferromagneticlike behavior was found in some substrates, in which metallic iron impurities were detected by x-ray photoelectron spectroscopy and total reflection x-ray fluorescence measurements. A thorough experimental investigation, using high resolution techniques, showed that these impurities were introduced by the procedure used to fix the substrates to the oven silicon holders. It is suggested that magnetism observed previously in nominally pure SnO2 films is of extrinsic origin. [ABSTRACT FROM AUTHOR]

Molecular diagnostic methods to detect and quantify viral RNA in clinical samples rely on the purification of the genetic material prior to reverse transcription polymerase chain reaction (qRT-PCR). Due to the large number of samples processed in clinical laboratories, automation has become a necessity in order to increase method processivity and maximize throughput per unit of time. An attractive option for isolating viral RNA is based on the magnetic solid phase separation procedure (MSPS) using magnetic microparticles. This method offers the advantage over other alternative methods of making it possible to automate the process. In this study, we report the results of the MSPS method based on magnetic microparticles obtained by a simple synthesis process, to purify RNA from oro- and nasopharyngeal swab samples of patients suspected of COVID-19 provided by three diagnostic laboratories located in the Buenos Aires Province, Argentina. Magnetite nanoparticles of Fe 3 O 4 (MNPs) were synthesized by the coprecipitation method and then coated with silica (SiO 2 ) produced by hydrolysis of tetraethyl orthosilicate (TEOS). After preliminary tests on samples from the A549 human lung cell line and swabs, an extraction protocol was developed. The quantity and purity of the RNA obtained were determined by gel electrophoresis, spectrophotometry, and qRT-PCR. Tests on samples from naso- and oropharyngeal swabs were performed in order to validate the method for RNA purification in high-throughput SARS-CoV-2 diagnosis by qRT-PCR. The method was compared to the spin columns method and the automated method using commercial magnetic particles. The results show that the method developed is efficient for RNA extraction from nasal and oropharyngeal swab samples, and also comparable to other extraction methods in terms of sensitivity for SARS-CoV-2 detection. Of note, this procedure and reagents developed locally were intended to overcome the shortage of imported diagnostic supplies as the sudden spread of COVID-19 required unexpected quantities of nucleic acid isolation and diagnostic kits worldwide., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors. Published by Elsevier Ltd.)

Although most cystic pancreatic lesions are pseudocysts, it is important to do a thorough differential diagnosis with true cystic tumors because cystic tumors are potentially malignant. Sometimes computed tomography and magnetic resonance imaging cannot establish the definitive diagnosis, making it necessary to perform other imaging tests such as endoscopic ultrasound, which in addition to morphological information, can also enable cytologic and biochemical analysis of the lesion through puncture and aspiration of its contents. Combining all these findings nearly always provides enough diagnostic information to allow the appropriate approach in each case. This article describes the specific morphological characteristics for each cystic pancreatic tumor on computed tomography, magnetic resonance imaging, and endoscopic ultrasound and reviews the guidelines for managing these types of lesions., (Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.)

We describe two new cases of Rosai-Dorfman disease with intrascrotal involvement. Also known as sinus histiocytosis with massive lymphadenopathy, this is a rare entity, usually presenting with massive bilateral cervical lymphadenopathy. It is associated with extranodal involvement in up to 40% of cases, commonly in the face and neck area. Isolated intrascrotal involvement with no lymphadenopathies is extremely rare, and its definitive diagnosis is histopathological. Although they are the most frequent type, not all intrascrotal lesions are neoplastic; therefore, it is important to know other possible etiologies and their radiogical features that might help in the diagnosis. We also review other cases of intrascrotal involvement reported in the literature, as well as a review clinical features, treatment and prognosis of this entity, and a differential diagnosis of solid intrascrotal lesions., (© 2015 The Japanese Urological Association.)

A 32-year-old man was examined with computed tomography before and after orthodontic treatment, and alveolar bone levels at the edentulous spaces were assessed. When the computed tomography scans were compared, 2.2 to 5.2 mm of additional craniocaudal alveolar bone remodeling by bodily tooth movement was found in the space-opening region. Bodily movement was achieved with single- and crossed-lever-arm mechanics. Root resorption measuring 1 to 4 mm was observed at the mandibular anterior region, where teeth were used for anchorage to upright the molars.