Nanostructured Au(111)/Oxide epitaxial heterostructures with tailoring plasmonic response by a one-step strategy

In this work, we present a strategy for developing epitaxial incommensurate nanostructured Au/oxide heterostructures with tunable plasmonic response. Previously, high-quality single-phase and single-oriented alfa-Fe2O3(0001) thin films were achieved, which have been used as a template for noble-metal epitaxial deposition. The complex systems have been grown by pulsed laser deposition on two different types of oxide substrates: alfa-Al2O3(0001) and SrTiO3(111). A one-step procedure has been achieved tailoring the isolated character and the morphological features of Au nanostructures through the substrate temperature during Au growth, without altering the structural characteristics of the hematite layer that is identified as a single iron oxide phase. The epitaxial character and the lattice coupling of Au/oxide bilayers are mediated through the sort of oxide substrate. Single-oriented Au(111) islands are disposed with a rotation of 30° between their crystallographic axes and those of alfa-Fe2O3(0001). The Au(111) and SrTiO3(111) lattices are collinear, while a rotation of 30° happens with respect to the alfa-Al2O3(0001) lattice. The crystallographic domain size and crystalline order of the hematite structure and the Au nanostructured layer are dependent on the substrate type and the Au growth temperature, respectively. Besides, the functional character of the complex systems has been tested. The localized surface plasmons related to Au nanostructures are excited and controlled through the fabrication parameters, tuning the optical resonance with the degree of Au nanostructuring.This work was supported by the Ministerio Español de Ciencia, Innovación y Universidades (MCIU), and the Consejo Superior de Investigaciones Cientificas (CSIC) through the project PIE-2010 6 OE 013. J.L.-S. and E.E. acknowledge the FPI fellowship and the Torres Quevedo contract (ref: PTQ-14-07289). The ESRF, MCIU, and CSIC are acknowledged for the provision of synchrotron radiation facilities. The authors thank Dr M.A. García for the useful discussion about the plasmonic results and Carlos Beltrán for technical support during the experiments at the BM25 beamline at The ESRF

Magnetosomes could be protective shields against metal stress in magnetotactic bacteria

Magnetotactic bacteria are aquatic microorganisms with the ability to biomineralise membrane-enclosed magnetic nanoparticles, called magnetosomes. These magnetosomes are arranged into a chain that behaves as a magnetic compass, allowing the bacteria to align in and navigate along the Earth's magnetic field lines. According to the magneto-aerotactic hypothesis, the purpose of producing magnetosomes is to provide the bacteria with a more efficient movement within the stratified water column, in search of the optimal positions that satisfy their nutritional requirements. However, magnetosomes could have other physiological roles, as proposed in this work. Here we analyse the role of magnetosomes in the tolerance of Magnetospirillum gryphiswaldense MSR-1 to transition metals (Co, Mn, Ni, Zn, Cu). By exposing bacterial populations with and without magnetosomes to increasing concentrations of metals in the growth medium, we observe that the tolerance is significantly higher when bacteria have magnetosomes. The resistance mechanisms triggered in magnetosome-bearing bacteria under metal stress have been investigated by means of x-ray absorption near edge spectroscopy (XANES). XANES experiments were performed both on magnetosomes isolated from the bacteria and on the whole bacteria, aimed to assess whether bacteria use magnetosomes as metal storages, or whether they incorporate the excess metal in other cell compartments. Our findings reveal that the tolerance mechanisms are metal-specific: Mn, Zn and Cu are incorporated in both the magnetosomes and other cell compartments; Co is only incorporated in the magnetosomes, and Ni is incorporated in other cell compartments. In the case of Co, Zn and Mn, the metal is integrated in the magnetosome magnetite mineral core.Te Spanish and Basque Governments are acknowledged for funding under projects number MAT2017- 83631-C3-R and IT-1245-19, respectively. Dr. L. Marcano acknowledges the fnancial support provided through a postdoctoral fellowship from the Basque Government

2-[18F]FDG PET/CT as a Predictor of Microvascular Invasion and High Histological Grade in Patients with Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) generally presents a low avidity for 2-deoxy-2-[18F]fluoro-d-glucose (FDG) in PET/CT although an increased FDG uptake seems to relate to more aggressive biological factors. To define the prognostic value of PET/CT with FDG in patients with an HCC scheduled for a tumor resection, forty-one patients were prospectively studied. The histological factors of a poor prognosis were determined and FDG uptake in the HCC lesions was analyzed semi-quantitatively (lean body mass-corrected standardized uptake value (SUL) and tumor-to-liver ratio (TLR) at different time points). The PET metabolic parameters were related to the histological characteristics of the resected tumors and to the evolution of patients. Microvascular invasion (MVI) and a poor grade of differentiation were significantly related to a worse prognosis. The SULpeak of the lesion 60 min post-FDG injection was the best parameter to predict MVI while the SULpeak of the TLR at 60 min was better for a poor differentiation. Moreover, the latter parameter was also the best preoperative variable available to predict any of these two histological factors. Patients with an increased TLRpeak60 presented a significantly higher incidence of poor prognostic factors than the rest (75% vs. 28.6%, p = 0.005) and a significantly higher incidence of recurrence at 12 months (38% vs. 0%, p = 0.014). Therefore, a semi-quantitative analysis of certain metabolic parameters on PET/CT can help identify, preoperatively, patients with histological factors of a poor prognosis, allowing an adjustment of the therapeutic strategy for those patients with a higher risk of an early recurrence

Magnetic study of co-doped magnetosome chains

Magnetotactic bacteria synthesize a chain of magnetic nanoparticles, called magnetosome chain, used to align and swim along the geomagnetic field lines. In particular, Magnetospirillum gryphiswaldense biomineralize magnetite, Fe3O4. Growing this species in a Co-supplemented medium, Co-doped magnetite is obtained, tailoring in this way the magnetic properties of the magnetosome chain. Combining structural and magnetic techniques such as transmission electron microscopy, energy-dispersive x-ray spectroscopy, X-ray absorption near edge structure, and X-ray magnetic circular dichroism, we determine that 1% of Co2+ substitutes Fe2+ located in octahedral places in the magnetite, thus increasing the coercive field. In the framework of the Stoner-Wohlfarth model, we have analyzed the evolution of the hysteresis loops as a function of temperature determining the different magnetic anisotropy contributions and their evolution with temperature. In contrast with the control magnetosome chains, whose effective anisotropy is uniaxial in the whole temperature range from 300 to 5 K, the effective anisotropy of Codoped magnetosome chains changes appreciably with temperature, from uniaxial down to 150 K, through biaxial down to 100 K, to triaxial below 100 K.L.M. acknowledges the Basque Government for her fellowship (PRE_2015_1_0130). We acknowledge the technical and human support provided by SGIker (UPV/EHU). Funding from the Spanish Government (project nos. MAT2014-55049-C2-R and MAT2017-83631-C3-R) and Basque Government (project n. IT711-13) is acknowledged. We thank the ESRF (CRG BM25 beamline-SpLine) and HZB for the allocation of synchrotron radiation beamtime and funding under the project CALIPSOplus (Grant Agreement 730872) from the EU Framework Programme for Research and Innovation HORIZON 2020. We thank R. Fernández-Pacheco for his assistance in the EDS measurements

Famílies botàniques de plantes medicinals

Facultat de Farmàcia, Universitat de Barcelona. Ensenyament: Grau de Farmàcia, Assignatura: Botànica Farmacèutica, Curs: 2013-2014, Coordinadors: Joan Simon, Cèsar Blanché i Maria Bosch.Els materials que aquí es presenten són els recull de 175 treballs d’una família botànica d’interès medicinal realitzats de manera individual. Els treballs han estat realitzat per la totalitat dels estudiants dels grups M-2 i M-3 de l’assignatura Botànica Farmacèutica durant els mesos d’abril i maig del curs 2013-14. Tots els treballs s’han dut a terme a través de la plataforma de GoogleDocs i han estat tutoritzats pel professor de l’assignatura i revisats i finalment co-avaluats entre els propis estudiants. L’objectiu principal de l’activitat ha estat fomentar l’aprenentatge autònom i col·laboratiu en Botànica farmacèutica

Unveiling the role of the hexagonal polymorph on SrAl2O4-based phosphors

International audienceIn persistent luminescence materials, the SrO-Al2O3 system has been mainly studied due to its chemical stability, higher photoluminescence response and longest green-afterglow times. Specifically, the research has focused on SrAl2O4 doped with europium and dysprosium. SrAl2O4 has two polymorphs: monoclinic polymorph (space group P2(1)) and hexagonal polymorph (space group P6(3)22). Besides, the coexistence of these two phases, monoclinic and hexagonal, appears in almost all the results. However, it is not clear how this coexistence influences optical response. Some authors have reported that only the monoclinic structure exhibits luminescence properties, while another suggests that the hexagonal SrAl2O4 polymorph has a higher emission efficiency than the monoclinic polymorph. Here we report a systematic evaluation of the effects of the stabilization of the hexagonal SrAl2O4 polymorph. We show that an interrelationship between the hexagonal polymorph and phosphorescent properties is the linchpin for the development of good luminescence properties. Remarkably, the stabilization of the hexagonal SrAl2O4 polymorph on the monoclinic-hexagonal polymorphic coexistence appears to be related to the preservation of the nanometric nature of the SrAl2O4-based system. Our results will help to understand the role of the hexagonal polymorph in the polymorphic coexistence on SrAl2O4-based systems and may facilitate the development of luminescent nanometric particles for the design and preparation of new light emitting materials

Factores protectores para disminuir el estrés laboral en trabajadores de una empresa de mensajería

Objective: Determine the relationship between Satisfaction, Motivation, Position and Hierarchy with the symptoms of work stress in workers of a courier company. Methods: Quantitative, correlational and cross-sectional study in a random sample. The motivation and labor satisfaction test and the Stress Symptoms Questionnaire were applied.Results: Were surveyed 72 workers from a company in Guadalajara Mexico. 64% (46) were male. The average age was 35 (±12.72) years. Marital status was predominantly married in 42% (30) participants. High scores were found in the dimensions of labor satisfaction 74% (53), position and hierarchy 62% (45), likewise the workers indicated to be moderately motivated 60% (43). In relation to the symptomatology of work stress, 69% (50), indicated to have physical symptoms while 40% (29) mental symptoms. Regarding the inferential analysis, a weak, inverse and significant correlation was found between the motivation dimensions (r= -0.276) and satisfaction (r= -0.323) with mental symptoms of stress. As well as a moderate and inverse correlation with the dimension of position and hierarchy with mental symptoms of stress (r= -0.401, p= 0.000)Conclusions: Motivation, satisfaction, position and hierarchy, can be considered as protective factors, before the symptoms of work stress.Objetivo: Determinar la relación entre Satisfacción, Motivación, Posición y Jerarquía con los síntomas de estrés laboral en trabajadores de una empresa de mensajería.Métodos: Estudio cuantitativo, correlacional y transversal en una muestra aleatoria. Se aplicó el test de Motivación y Satisfacción Laboral y el Cuestionario de Síntomas de estrés.Resultados: Se encuestó a 72 trabajadores de una empresa de Guadalajara México. El 64% (46) fueron masculinos y 36% (26), femeninos. La edad media fue 35 (± 12.72) años. Estado civil predominante fue casados en 42% (30) participantes. Se encontraron puntuaciones altas en las dimensiones deSatisfacción Laboral 74% (53), Posición y jerarquía 62% (45), así mismo los trabajadores indicaron sentirse medianamente motivados 60% (43). En relación con la sintomatología de estrés laboral, el 69% (50), indicaron tener síntomas físicos mientras que 40% (29) síntomas mentales. En cuanto al análisis inferencialse encontró una correlación débil, inversa y significativa entre las dimensiones de motivación (r=-.276) y satisfacción (r= -0.323) con síntomas mentales de estrés. Así como una correlación modera e inversa con la dimensión de posición y jerarquía con síntomas mentales de estrés (r= -0.401, p= 0.000).Conclusiones: La motivación, satisfacción, posición y jerarquía, se pueden considerar como factores protectores, ante los síntomas de estrés laboral

Stabilization of Epitaxial α‑Fe₂O₃ Thin Films Grown by Pulsed Laser Deposition on Oxide Substrates

We have grown epitaxial incommensurate α-Fe₂O₃ thin films on α-Al₂O₃(0001), SrTiO₃(111), and LaAlO₃(001) substrates, identifying hematite as single iron oxide phase stabilized. We demonstrate that a different lattice coupling behavior as a function of the selected oxide substrate mediates the epitaxial character. Single-oriented α-Fe₂O₃(0001) layers are obtained on α-Al₂O₃(0001) and SrTiO₃(111) substrates, whereas on the LaAlO₃(001) substrate, the hematite layer is found to grow along the <i>r</i>-plane to adapt its hexagonal lattice on the cubic lattice of the substrate, evidencing a single-oriented (11̅02) layer. In the film plane, crystallographic axes of α-Fe₂O₃(0001) are collinear with the α-Al₂O₃(0001) ones, while a rotation of 30° is found between those of α-Fe₂O₃(0001) and SrTiO₃(111). On LaAlO₃(001), α-Fe₂O₃(11̅02) adopts an in-plane orthorhombic structure rotated 45° respect to the substrate lattice. The crystallographic domain size and the crystalline order are dependent on the incommensurate lattice coupling mechanism. Larger values are obtained for layers grown on α-Al₂O₃(0001), while lower values correspond to the hematite deposited on LaAlO₃(001). Moreover, an Fe–O elongation and Fe–Fe contraction of first neighbors distances as well as a dependency on surface flatness as a function of the substrate lattice parameter is also found

Informe final Design Thinking i suport tecnològic per una docència transversal

La dècima Jornada del Grup d'Innovació Docent Trans@net celebrada en tres sessions formatives pels docents de treball social i oberta a la comunitat universitària de la Universitat de Barcelona. "DesignThinking i suport tecnològic per una docència transversal" és un espai dedicat a pensar com dissenyem una docència transversal i tecnològica sense perdre l'essència de l'ensenyament del treball social.RIMDA, ICE-ID