Anomalous precursor diamagnetism at low reduced magnetic fields and the role of Tc inhomogeneities in the superconductors Pb55In45 and underdoped La1.9Sr0.1CuO4

The magnetic field dependence of the magnetization was measured above the superconducting transition in a high-Tc underdoped cuprate La1.9Sr0.1CuO4 and in a low-Tc alloy (Pb55In45). Near the superconducting transition [typically for (T-Tc)/Tc<0.05] and under low applied magnetic field amplitudes [typically for H/Hc2(0)<0.01, where Hc2(0) is the corresponding upper critical field extrapolated to T=0 K] the magnetization of both samples presents a diamagnetic contribution much larger than the one predicted by the Gaussian Ginzburg-Landau (GGL) approach for superconducting fluctuations. These anomalies have been already observed in cuprate compounds by various groups and attributed to intrinsic effects associated with the own nature of these high-Tc superconductors. However, we will see here that our results in both high and low-Tc superconductors may be explained quantitatively, and consistently with the GGL behavior observed at higher fields, by just taking into account the presence in the samples of an uniform distribution of Tc inhomogeneities. These Tc inhomogeneities, which may be in turn associated with stoichiometric inhomogeneities, were estimated from independent measurements of the temperature dependence of the field-cooled magnetic susceptibility under low applied magnetic fields.Comment: 25 pages, including 6 figures and 1 table. Typos corrected. Compacte

Gestión administrativa y satisfacción laboral del personal en una institución pública de la Región Ayacucho

Esta investigación se plantea como objetivo general “determinar la relación entre la gestión administrativa y la satisfacción laboral del personal en una institución pública de la Región Ayacucho, 2021”. Se apoya para ello en un tipo de investigación básica, enfoque cuantitativo, diseño no experimental y correlacional, que contempla la aplicación de encuestas a una muestra de 172 funcionarios de una institución pública de la Región Ayacucho. Se emplean dos cuestionarios, cuyos ítems se miden a través de una escala de Likert, que alcanzaron un nivel de confiabilidad muy bueno (0,935 y 0,926). Los resultados obtenidos permitieron concluir que existe una relación significativa, positiva y considerable entre las variables “gestión administrativa” y “satisfacción laboral” del personal en una institución pública de la Región Ayacucho, 2021, puesto que su valor de significancia bilateral es menor a 0,05 y el coeficiente de correlación de Pearson es de 0,683. Así mismo existe una relación significativa, positiva y considerable entre la satisfacción laboral y todas las dimensiones de la gestión administrativa: planificación, organización, dirección y control

Effect of the viscosity ratio on the PLA/PA10.10 bioblends morphology and mechanical properties

PLA bio-blends with a predominantly biosourced PA10.10 in the composition range 10-50wt.% were prepared by melt blending in order to overcome the advanced brittleness of PLA. Due to the inherent immiscibility of the blends, 30 wt.% of PA was needed to achieve a brittle-to-ductile transition and a co-continuous morphology was predicted at 58 wt.% of PA. The initial enhancement of the PLA rheological behaviour through the environmentally friendly reactive extrusion process yielded a finer and more homogeneous microstructure and hence enhanced the mechanical properties of the bio-blends at much lower PA contents. The brittle-to-ductile transition could be achieved with only 10 wt.% and co-continuity was observed already at 44 wt.% of PA. Results indicate the significant potential of modifying PLA flow behaviour as a promising green manufacturing method toward expanding PLA-based bio-blends applications.Peer ReviewedPostprint (published version

Communication of the commitment to sustainability and the UN SDGs in the Iberian Foundations

In this paper we analyse the contribution of two Iberian Foundations to the United Nations SDGs (Global Goals). In particular, we studied, the case of Eugénio de Almeida Foundation, from Portugal, and Yuste Foundation, from Spain, between 2016 and 2018. To achieve the main objective, three specific objectives were defined: the first one is to understand if sustainability is present in the Foundations Mission, Vision and Values; the second one is to analyse how the activities developed by each Foundations contribute to the sustainable development goals (SDGs) and relate these activities to the SDGs targets; and finally to do a comparative analysis of the results of the two foundations. To reach these objectives, we use the case study method based on the analysis of annual reports and websites of the two Foundations and cross-referenced information about the mission, objectives, values and activities developed since 2016 with the specific targets of Global Goals. This paper show that Iberian Foundations contribute to the sustainable development goals, since its mission fits the SDGs as its activities have a strong social nature and aim at sustainable development in the regions where they operate and beyond. However, we do not find the reporting evidence because the Foundations do not provide sustainability reports, nor do they provide sustainability information in their annual reports and accounts, or on their web sites. The study will present contributions at several levels: literature and practice. It makes contributions to the literature on relationships between sustainability practices and sustainability report; the regulation and institutionalization of sustainability practices and reporting for SDGs. Also, it contributes to a better understanding of the role of Iberian Foundations as partnerships for global goals and their contribution to the effective develop, accountable and transparent institutions at all levels

PLA/PA bio-blends: induced morphology by extrusion

The effect of processing conditions on the final morphology of Poly(Lactic Acid) (PLA) with bio-based Polyamide 10.10 (PA) 70/30 blends is analyzed in this paper. Two types of PLA were used: Commercial (neat PLA) and a rheologically modified PLA (PLAREx), with higher melt elasticity produced by reactive extrusion. To evaluate the ability of in situ micro-fibrillation (µf) of PA phase during blend compounding by twin-screw extrusion, two processing parameters were varied: (i) Screw speed rotation (rpm); and (ii) take-up velocity, to induce a hot stretching with different Draw Ratios (DR). The potential ability of PA-µf in both bio-blends was evaluated by the viscosity (p) and elasticity (k’) ratios determined from the rheological tests of pristine polymers. When PLAREx was used, the requirements for PA-µf was fulfilled in the shear rate range observed at the extrusion die. Scanning electron microscopy (SEM) observations revealed that, unlike neat PLA, PLAREx promoted PA-µf without hot stretching and the aspect ratio increased as DR increased. For neat PLA-based blends, PA-µf was promoted during the hot stretching stage. DMTA analysis revealed that the use of PLAREx PLAREx resulted in a better mechanical performance in the rubbery region (T > Tg PLA-phase) due to the PA-µf morphology obtained.Peer ReviewedPostprint (published version

Antibody-Capped Mesoporous Nanoscopic Materials:Design of a Probe for the Selective Chromo-FluorogenicDetection of Finasteride

[EN] The synthesis of capped mesoporous silica nanoparticles (MSN) conjugated with an antibody (AB) as a gatekeeper has been carried out in order to obtain a delivery system able to release an entrapped cargo (dye) in the presence of a target molecule (antigen) to which the conjugated antibody binds selectively. In particular, MSN loaded with rhodamine B and functionalized on the external surface with a suitable derivative of N-(t-butyl)- 3-oxo-(5a,17b)-4-aza-androst-1-ene-17-carboxamide (finasteride) have been prepared (S1). The addition of polyclonal antibodies against finasteride induced capping of the pores due to the interaction with the anchored hapten-like finasteride derivative to give a MSN¿hapten¿AB nanoparticle S1-AB. It was found that the addition of capped material S1-AB to water solutions containing finasteride resulted in displacement of the antibody, pore uncapping and entrapped-dye release. The response of the gated material is highly selective, and only finasteride, among other steroids, was able to induce a significant uncapping process. Compared with finasteride, the finasteride metabolite was able to release 17% of the dye, whereas the exogen steroids testosterone, metenolone and 16-b-hydroxystanozolol only induced very little release of rhodamine B (lower than 10%) from aqueous suspensions containing sensing solid S1-AB. A detection limit as low as 20 ppb was found for the fluorimetric detection of finasteride. In order to evaluate a possible application of the material for label-free detection of finasteride, the capped material was isolated and stored to give final sensing solid S1-AB-i. It was found to display a similar behavior towards finasteride as to that shown by freshly prepared S1-AB; even after a period of two months, no significant loss of selectivity or sensitivity was noted. Moreover, to study the application for the detection of finasteride in biological samples, this ¿aged¿ material, S1-AB-i, was tested using commercially available blank urine as matrix. Samples containing 70 and 90% blank urine were spiked with a defined amount of finasteride, and the concentration was determined using capped S1-AB-i. Recovery ranges from 94% to 118% were reached.Financial support from the Spanish Government (project MAT2009-14564-C04-01) and the Generalitat Valenciana (Spain) (projects PROMETEO/2009/016 and PROMETEO/2010/008) is gratefully acknowledged. E. C. thanks the Minesterio de Ciencia e Innovacion (MICINN, Spain) for her fellowship.Climent Terol, E.; Martínez Mañez, R.; Maquieira Catala, Á.; Sancenón Galarza, F.; Marcos Martínez, MD.; Brun Sánchez, EM.; Soto Camino, J.... (2012). Antibody-Capped Mesoporous Nanoscopic Materials:Design of a Probe for the Selective Chromo-FluorogenicDetection of Finasteride. ChemistryOpen. 1:251-259. https://doi.org/10.1002/open.201100008S251259

La evaluación formativa y su carácter humanista en la Educación Básica de la sociedad actual Formative assessment and its humanistic character in Basic Education today society

The study aimed to show the essence of formative education adapted to the new educational paradigms at all levels of education and that responds to the needs of conceptual changes to the quantitative and qualitative transformations of society. The study design was non-experimental, cross-sectional. The sample consisted of 36 subjects and a questionnaire was used. It was concluded that the proper application of formative assessment as a process and result is an interactive responsibility of the teacher and student

An Active Learning Didactic Proposal with Human-Computer Interaction in Engineering Education: A Direct Current Motor Case Study

Engineering education requires learning strategies to engage students and improve the development of disciplinary and transversal competencies. Additionally, as economic resources are generally limited, it is sought to avoid investing large sums of money in software and hardware, as well as in fitting out laboratories. This work presents a didactic proposal within the framework of active and collaborative learning that includes the flipped classroom technique to be applied in the curriculum of undergraduate engineering programs and inside a massive flexible digital master class. The activity is the mathematical modeling, simulation, and control system of a direct current motor where simulation work is carried out in open license computational packages. Students understand the physical phenomena involved in the motor’s modeling and the input–output variables’ relations. Moreover, an analogy between an electromechanical and a pure electrical model is carried out, where the relevant variables respond in an agile and reliable manner. To validate the modeling, the differential equations are solved by applying numerical methods, and tested for control purposes. The activity has been validated with a rule-based system applied to a Likert scale survey data. This type of human–computer interaction, in the context of active learning, could engage students and motivate them to develop competencies that are highly appreciated by industry practitioners. View Full-Tex

Expression and cellular localization of 15-hydroxy-prostaglandin-dehydrogenase in abdominal aortic aneurysm

PGE2 has been implicated in abdominal aortic aneurysm (AAA) associated hypervascularization. PGE2-metabolism involves 15-hydroxyprostaglandin-dehydrogenase (15-PGDH) the expression of which in AAA is unknown. The aim of this study was to examine the expression and cell distribution of 15-PGDH in AAA. Here, we show that 15-PGDH mRNA levels were significantly higher in aorta samples from patients undergoing AAA repair than in those from healthy multiorgan donors. Consequently, the ratio of metabolized PGE2 secreted by aortic samples was significantly higher in AAA. AAA production of total PGE2 and PGE2 metabolites correlated positively with PGI2 production, while the percentage of metabolized PGE2 correlated negatively with the total amount of PGE2 and with PGI2. Transcript levels of 15-PGDH were statistically associated with leukocyte markers but did not correlate with microvascular endothelial cell markers. Immunohistochemistry revealed 15-PGDH in the areas of leukocyte infiltration in AAA samples, mainly associated with CD45-positive cells, but not in normal aorta samples. We provide new data concerning 15-PGDH expression in human AAA, showing that 15-PGDH is upregulated in AAA and mainly expressed in infiltrating leukocytes. Our data suggest that microvasculature was not involved in PGE2 catabolism, reinforcing the potential role of microvasculature derived PGE2 in AAA-associated hypervascularization.This work was supported by grants SAF2010-21392 (LV), SAF2013-46707-R (LV, MC), SAF2012-40127 (JM-G) from the Spanish Ministry of Economy and Competiveness, PI12/01952 (CR) and Red de Investigación Cardiovascular RD12/0042/0051 (LV) and RD12/0042/0053 (JM-G) from the Instituto de Salud Carlos III. The study was cofunded by Fondo Europeo de Desarrollo Regional (FEDER), a way to make Europe. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer Reviewe

Hybrid materials with nanoscopic anion-binding pockets for the colorimetric sensing of phosphate in water using displacement assays

Mesoporous amino-functionalised solids containing certain dyes have been used as suitable anion hosts in displacement assays for the colorimetric signalling of phosphate in water.Amoros del Toro, Pedro Jose, [email protected]