384 research outputs found

    Magnetic properties of epsilon iron(III) oxide nanorod arrays functionalized with gold and copper(II) oxide

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    A sequential chemical vapor deposition (CVD) - radio frequency (RF)-sputtering approach was adopted to fabricate supported nanocomposites based on the scarcely investigated \u3b5-iron(III) oxide polymorph. In particular, \u3b5-Fe2O3 nanorod arrays were obtained by CVD, and their subsequent functionalization with Au and CuO nanoparticles (NPs) was carried out by RF-sputtering under mild operational conditions. Apart from a multi-technique characterization of material structure, morphology and chemical composition, particular efforts were dedicated to the investigation of their magnetic properties. The pertaining experimental data, discussed in relation to the system chemico-physical characteristics, are directly dependent on the actual chemical composition, as well as on the spatial distribution of Au and CuO nanoparticles. The approach adopted herein can be further implemented to control and tailor different morphologies and phase compositions of iron oxide-based nanomaterials, meeting thus the open requests of a variety of technological utilizations

    RIPENSARE LA QUESTIONE INDIGENA IN MESSICO. ALCUNE RIFLESSIONI TRA SPAZI URBANI, DISCORSI POLITICI E PRATICHE IDENTITARIE

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    ItalianoNel presente testo si propongono alcune riflessioni relative alla “questione indigena” in Messico; l'analisi proposta problematizza l’incontro con l’alterità indigena al momento della conquista, durante l’affermazione del modello identitario e politico del mestizaje e nel mondo contemporaneo segnato dal paradigma del modernismo e della colonialità, tentando di stimolare la costruzione di uno sguardo antropologico critico e sospettoso verso semplicistiche essenzializzazioni ideologiche.Español En el presente ensayo se proponen algunas reflexiones sobre la "cuestión indígena" en México. El análisis propone problematizar el incontro con la alteridad indígenas en el momento de la conquista, en la afirmación del modelo político del mestizaje y en el mundo contemporáneo, marcado por el paradigma de la modernidad y de la colonialidad, tratando de estimular la construcción de una mirada antropológica crítica y sospechosa sobre simplistas naturalizaciones ideológicas

    XPS analysis of Fe2O3-TiO2-Au nanocomposites prepared by a plasma-assisted route

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    Fe2O3 nanodeposits have been grown on fluorine-doped tin oxide (FTO) substrates by plasma enhanced-chemical vapor deposition (PE-CVD). Subsequently, the obtained systems have been functionalized through the sequential introduction of TiO2 and Au nanoparticles (NPs) by means of radio frequency (RF)-sputtering. The target nanocomposites have been specifically optimized in view of their ultimate functional application in solar-driven H2 generation. In the present study, our attention is focused on a detailed X-ray photoelectron spectroscopy (XPS) characterization of the surface composition for a representative Fe2O3-TiO2-Au specimen. In particular, this report provides a detailed discussion of the analyzed C 1s, O 1s, Fe 2p, Ti 2p, and Au 4f regions. The obtained results point to the formation of pure Fe2O3-TiO2-Au composites, with gold present only in its metallic state and each of the constituents maintaining its chemical identity

    A study of Pt-/alpha-Fe2O3 nanocomposites by XPS

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    alpha-Fe2O3 matrices were deposited on Fluorine-doped Tin Oxide (FTO) substrates by Plasma Enhanced- Chemical Vapor Deposition (PE-CVD) from Fe(hfa)_2TMEDA (hfa = 1,1,1,5,5,5-hexafluoro-2,4-pentanedionate; TMEDA = N,N,N’,N’-tetramethylethylenediamine). The obtained nanosystems were subsequently functionalized by platinum nanoparticles (NPs) via Radio Frequency (RF)-sputtering, exposing samples either to a pre- or post-sputtering thermal treatment at 650°C for one hour in air. Interestingly, Pt oxidation state in the final composite systems strongly depended on the adopted processing conditions. In this work, a detailed X-ray Photoelectron Spectroscopy (XPS) analysis was carried out in order to investigate the material chemical composition, with particular regard to the relative Pt(0)/Pt(II)/Pt(IV) content. The obtained results evidenced that, when annealing is performed prior to sputtering, only PtO and PtO2 are revealed in the final Pt/alpha-Fe2O3 nanocomposite. In a different way, annealing after sputtering results in the co-presence of Pt(0), Pt(II) and Pt(IV) species, the former arising from the thermal decomposition of PtO2 to metallic platinum

    Two cases of COPD benefitting from therapy with roflumilast

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    Two clinical cases of chronic obstructive pulmonary disease (COPD) stage II patients are reported here. One case refers to a patient with hypoxemia associated to severe air flow limitation, chronic bronchitis and frequent exacerbation events. A significant improvement of patient’s conditions was observed after pharmacological treatment with roflumilast. The second case refers to a patient who refused to adhere to prescribed therapy but adhered to roflumilast therapy, eventually achieving a good response. Both cases highlight roflumilast’s efficacy in improving health conditions of COPD patients

    Effect of Circuit Geometry on Steady Flow Performance of an Automotive Turbocharger Compressor

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    Downsizing and turbocharging are today considered an effective way to reduce CO2 emissions in automotive gasoline engines. To this aim, a deep knowledge of turbocharger behavior could be a key solution to improve the engine-turbocharger matching calculation. The influence of the intake system geometry on the surge line position is an important aspect to guide the project of the intake manifold, enlarging the compressor stable zone. This aspect has a considerable impact on engine performance, especially during transient operation. A wide experimental investigation was carried out at the turbocharger test facility of the University of Genoa on a small turbocharger compressor. Compressor characteristic curves measured considering an automotive intake circuit are compared with standard maps provided by turbocharger\u2019s manufacturer. This information allows the optimization of 1D model implementing more realistic maps of compressor. The influence of three different layouts has been investigated varying overall circuit volume and length, keeping values in a range compatible with passenger cars packaging constraints. In the paper, the main results of the experimental campaign are presented taking into account the influence of geometry variations on compressor map and surge line position

    Mesenchymal Stem Cells Increase Neo-Angiogenesis and Albumin Production in a Liver Tissue-Engineered Engraftment

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    The construction of a three-dimensional (3D) liver tissue is limited by many factors; one of them is the lack of vascularization inside the tissue-engineered construct. An engineered liver pocket-scaffold able to increase neo-angiogenesis in vivo could be a solution to overcome these limitations. In this work, a hyaluronan (HA)-based scaffold enriched with human mesenchymal stem cells (hMSCs) and rat hepatocytes was pre-conditioned in a bioreactor system, then implanted into the liver of rats. Angiogenesis and hepatocyte metabolic functions were monitored. The formation of a de novo vascular network within the HA-based scaffold, as well as an improvement in albumin production by the implanted hepatocytes, were detected. The presence of hMSCs in the HA-scaffold increased the concentration of growth factors promoting angiogenesis inside the graft. This event ensured a high blood vessel density, coupled with a support to metabolic functions of hepatocytes. All together, these results highlight the important role played by stem cells in liver tissue-engineered engraftment

    WO3-decorated ZnO nanostructures for light-activated applications

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    In the present work, a two-step vapor-phase route was implemented for the tailored design of ZnO\u2013WO3 nanoheterostructures supported on fluorine-doped tin oxide (FTO) substrates. Under optimized conditions, the sequential use of chemical vapor deposition (CVD) and radio frequency (RF)-sputtering for the deposition of zinc and tungsten oxides respectively, resulted in the growth of calyx-like ZnO nanostructures uniformly decorated by a conformal dispersion of low-sized WO3 nanoparticles. The target materials were characterized by means of a multi-technique approach, with particular regard to their structural, compositional, morphological and optical properties. Finally, their photocatalytic performances were preliminarily tested in the abatement of NOX gases (NO and NO2). Due to the unique porous morphology of the ZnO nanodeposit and the high density of ZnO\u2013WO3 heterojunctions, WO3-decorated ZnO revealed appealing De-NOX characteristics in terms of both degradation efficiency and selectivity. Such features, along with the photoinduced superhydrophilicity and self-cleaning properties of the present nanomaterials, candidate them as promising functional platforms for applications in smart windows and building materials for environmental remediation

    Multiple Bulky Lymph Nodal Metastasis in Microinvasive Cervical Cancer: A Case Report and Literature Review

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    Microinvasive squamous cell cervival carcinoma is characterized by an exceptional incidence of lymph nodal metastasis. We report the case of a 45-year-old woman affected by IA1 squamous cell carcinoma, found to have massive pelvic lymph nodal metastasis. After a systematic pelvic and aortic selective lymphadenectomy, at 16 months of follow-up, she is still disease-free. Patients suitable for conservative therapy should be carefully counselled about the established risks and benefits of nondestructive treatment options
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