Estilos de liderazgo y su influencia en la motivación de los colaboradores de una empresa de alquiler de maquinaria pesada

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A 2-D π–π dimer model system to investigate structure-charge transfer relationships in rubrene

© The Royal Society of Chemistry 2019Rubrene (5,6,11,12-tetraphenyltetracene) is undoubtedly one of the best performing organic charge transfer mediating materials, with experimentally determined mobilities up to 40 cm2 V−1 s−1. Consequently, there has been increasing interest by means of crystal engineering in trying to generate rubrene-based materials with analogous or even superior conducting properties. Often, experimental measurements are carried out in thin film architectures of these materials, where measured properties can be detrimentally impacted by device manufacture rather than intrinsic charge transfer properties of the material. The latter results in discarding potential good performers. To address these concerns, we report a two-dimensional model system that will allow researchers to predict charge transfer properties of their materials solely requiring the coordinates of the π–π stacking motifs. We envisaged this study to be of significant interest to the increasingly large community of materials scientists devoted to the realisation of improved organic charge mediating materials and particularly to those engaged in exploiting rubrene-based architectures.Peer reviewedFinal Accepted Versio

La cultura i el clima organitzacional a l'Educació Secundària

La importància de l'educació secundària per al desenvolupament personal i social i les diferents problemàtiques que actualment presenta obliguen a fer diferents actuacions (polítiques, legals, científiques i tècniques) que permetin optimitzar i millorar la realitat actual. En el present article exposem resumidament les principals característiques d'una recerca que s'ha desenvolupat amb l'objectiu de millorar el funcionament dels centres d'educació secundària (IES) a partir del diagnòstic detallat de les variables cultura i clima organitzatius. Presentem una recerca desenvolupada per un equip de treball format per professors i directors d'IES, professionals de l'administració educativa i acadèmics del món universitari. Això ens ha permès fer un plantejament global i plural de la realitat i coordinar els diferents agents implicats i els professionals de l'àmbit. Partim presentant molt breument el marc teòric de referència. En segon lloc es determinen les bases metodològiques i els aspectes empírics de la recerca. A més del disseny dels instruments per al diagnòstic de la cultura i el clima dels centres. Finalment, es presenten resumidament els resultats i les principals conclusions de l'estudi.La importancia de la educación secundaria para el desarrollo personal y social y las diversas disfunciones y problemas que presenta obligan a realizar diferentes actuaciones (políticas, legales, científicas y técnicas) que permitan superar y optimizar la actual situación. En el presente artículo se exponen de forma sintética los principales rasgos y características de una investigación que ha tenido como objeto de estudio la mejora del funcionamiento de los centros de educación secundaria (IES) a partir del diagnóstico detallado de las variables de su clima y cultura institucional. Presentamos una investigación desarrollada por un equipo de trabajo configurado por profesores y directores de IES, profesionales de la administración educativa y académicos de la universidad que ha permitido plantear un enfoque global, plural y coordinado de los diferentes agentes implicados y profesionales del ámbito. Partimos presentando de forma sucinta el marco teórico en el que hemos basado nuestra investigación. Seguidamente se determinan las bases metodológicas y de carácter más empírico, destacando por un lado el estudio de casos como metodología de trabajo y el diseño o aplicación de instrumentos para el análisis y el diagnóstico del clima y cultura institucional. Finalmente se presentan de forma resumida los resultados y las principales conclusiones del estudio.The importance of the education secondary for the personal and social development and the diverse problems that present/display force to make different performances (political, legal, scientific and technical) that allows to surpass and to optimize the present one situation. In the present article they are exposed of synthetic form the main characteristics and characteristics of one investigation that it has had as study object the improvement of the operation of the centers of secondary education (IES) from the detailed diagnosis of the variables of its climate and institutional culture. We presented/displayed an investigation developed by a work party formed by professors and directors of IES, academic professionals of the educative administration and of university that has allowed to raise a global approach, plural and coordinated of the different professional implied agents y from the scope. We started off presenting/displaying of the theoretical frame on which we have based our investigation. Next the methodologic bases and of more empirical character are determined, emphasizing by a side the study of cases like work methodology and design or application of instruments for the analysis and diagnosis of the climate and institutional culture. Finally the results appear of summarized form and the main conclusions of the study

Handling of lipemic samples in the clinical laboratory

Interferences in the clinical laboratory may lead physicians misinterpret results for some biological analytes. The most common analytical interferences in the clinical laboratory include hemolysis, icterus and lipemia. Lipemia is defined as turbidity in a sample caused by the accumulation of lipoproteins, mainly very-low density lipoproteins (VLDL) and chylomicrons. Several methods are available for the detection of lipemic samples, including the lipemic index, or triglyceride quantification in serum or plasma samples, or mean corpuscular hemoglobin (MCHC) concentration in blood samples. According to the European Directive 98/79/CE, it is the responsibility of clinical laboratories to monitor the presence of interfering substances that may affect the measurement of an analyte. There is an urgent need to standardize interference studies and the way interferences are reported by manufacturers. Several methods are currently available to remove interference from lipemia and enable accurate measurement of biological quantities. The clinical laboratory should establish a protocol for the handling of lipemic samples according to the biological quantity to be tested

Manejo de muestras lipémicas en el Laboratorio Clínico

Las interferencias analíticas en el laboratorio clínico pueden causar errores en la interpretación de los resultados de diversas magnitudes biológicas por parte del médico peticionario. Las interferencias analíticas más frecuentemente observadas en el laboratorio clínico son la hemólisis, ictericia y lipemia. La lipemia se define como la turbidez de la muestra causada por la acumulación de lipoproteínas, principalmente lipoproteínas de muy baja densidad (VLDL) y quilomicrones. Existen diversos métodos de detección de muestras lipémicas, como por ejemplo, el índice lipémico o la determinación de triglicéridos en muestras de suero o plasma o la Concentración de Hemoglobina Corpuscular Media (CHCM) en muestras de sangre. Las empresas de diagnóstico in vitro son las responsables, según la Directiva Europea 98/79/CE, de realizar el estudio de las sustancias interferentes que pueden afectar a la medición de una magnitud. Existe una necesidad urgente de estandarizar la forma

Dealing with long-range interactions in the determination of polyelectrolyte ionization properties. Extension of the transfer matrix formalism to the full range of ionic strengths

The ionization state of charged macromolecules in solution is usually determined by the extent of the binding processes. These processes are very sensitive to the ionic strength of the medium, which are of long-range nature. The ionization properties of weak polyelectrolytes can be described by means of Ising-type models, which is only feasible when long-range interactions are neglected. Here, this formalism is extended to include long-range interactions by introducing a modified free energy involving only effective short-range interaction parameters. These parameters can be systematically calculated by using the Gibbs-Bogoliubov variational principle. The technique is illustrated with the calculation of titration curves of homogeneous and heterogeneous polyelectrolytes in a wide range of ionic strengths. The correction of the site protonation free energy (first order correction) is enough to obtain an excellent agreement between theory and Monte Carlo simulations. Corrections to other cluster parameters (higher order corrections) are also implemented. In general, the correction to a particular parameter represents the average change in the long-range energy when a new interaction is created in the polyelectrolyte. The method presented here represents an improvement in the description of the ionization state of polyelectrolytes that can be relevant in a wide range of areas.represents the average change in the long range energy when a new interaction (of the type described by the cluster parameter), is created in the polyelectrolyte. The method presented here represents an improvement in the description of the ionization state of charged macromolecules that can be relevant in a wide range of areas such as biochemistry, environmental chemistry, materials science, etc

Characterization of 3d printing filaments applied in restoration of sensitive archaeological objects using rapid prototyping

[EN] Purpose The purpose of this paper is to characterize three-dimensional (3D) printing filaments commonly used in fused deposition modeling (FDM) to determine their viability for restoration and conservation treatments. Design/methodology/approach Eight current filaments for FDM from six polymeric materials have been characterized to determine their suitability for restoration and conservation treatments. For testing these filaments, specimens are printed with acrylonitrile-butadiene-styrene; polylactic acid; polylactic acid with CaCO3 (E.P.); polyethylene terephthalate glycol; polypropylene; and high-impact polystyrene. Suitability of a filament was verified using the Oddy test by detecting the action of volatile pollutants released from the filaments. The morphological and color changes were observed after allowing them to degrade under the exposure of UV radiation. The samples were then analyzed using Fourier-transform infrared spectroscopy. In addition, gas chromatography-mass spectroscopy technique was applied to complete the characterization of the printed filaments. Findings Materials investigated are suitable for restoration purposes ensuring long-term stability. Rapid prototyping using FDM is appropriate for restoring sensitive archaeological objects allowing reconstruction of parts and decreasing risk while manipulating delicate artifacts. Originality/value Rapid prototyping using FDM was chosen for the restoration of a fragile and sensitive archaeological glass bowl from Manises Ceramic Museum.This work is supported by the Spanish Ministry of Economy, Industry and Competitiveness and the European Regional Development Fund (ERDF), in the context of the research project "Desarrollo de un Sistema Integrado de Restauracion, Recomposicion, Restitucion y Representacion de Fragmentos Arqueologicos": HAR2015-69408-R (MINECO-FEDER).Aura-Castro, E.; Díaz-Marín, C.; Mas-Barberà, X.; Sánchez López, M.; Vendrell Vidal, E. (2021). Characterization of 3d printing filaments applied in restoration of sensitive archaeological objects using rapid prototyping. Rapid Prototyping Journal. 27(4):645-657. https://doi.org/10.1108/RPJ-06-2019-0153S64565727

Sal k 5, a member of the widespread Ole e 1-like protein family, is a new allergen of Russian thistle (Salsola kali) pollen.

Salsola kali is an Amaranthaceae weed with important repercussions for pollinosis in temperate areas. Ole e 1-like members are relevant allergens in pollen from different species. We aimed to characterize and produce as recombinant allergen S. kali Ole e 1-like protein. METHODS:The natural allergen was purified at homogeneity after three chromatographic steps. Specific cDNA was sequenced and expressed in Pichia pastoris yeast. Structural relationships of natural and recombinant forms were carried out by 2D electrophoresis and spectroscopic analyses. Its immunological relevance was analyzed by ELISA and immunoblotting using an IgG antiserum and monoclonal antibodies specific to Ole e 1, as well as sera from 57 allergic patients recruited from two Spanish regions where this pollinosis is frequent. RESULTS:The purified allergen, Sal k 5, is an acidic glycoprotein of 151 amino acid residues and 17,628 Da of molecular mass. Its amino acid sequence exhibits 68 and 32% identity with the allergens of Che a 1 and Ole e 1, respectively. The recombinant protein was correctly processed and its structural and immunologic equivalence to the natural form was proven. A sensitization frequency between 30 and 40% was observed in pollinic patients from the center and east coast of Spain. CONCLUSIONS:Sal k 5 is a member of the Ole e 1-like protein family which can be considered an important allergen from S. kali. Its inclusion in diagnosis protocols would allow the accurate defining of patients allergic to this pollen

Detection of an optical transient following the 13 March 2000 short/hard gamma-ray burst

We imaged the error box of a gamma-ray burst of the short (0.5 s), hard type (GRB 000313), with the BOOTES-1 experiment in southern Spain, starting 4 min after the gamma-ray event, in the I-band. A bright optical transient (OT 000313) with I = 9.4 +/- 0.1 was found in the BOOTES-1 image, close to the error box (3-sigma) provided by BATSE. Late time VRIK'-band deep observations failed to reveal an underlying host galaxy. If the OT 000313 is related to the short, hard GRB 000313, this would be the first optical counterpart ever found for this kind of events (all counterparts to date have been found for bursts of the long, soft type). The fact that only prompt optical emission has been detected (but no afterglow emission at all, as supported by theoretical models) might explain why no optical counterparts have ever been found for short, hard GRBs.This fact suggests that most short bursts might occur in a low-density medium and favours the models that relate them to binary mergers in very low-density enviroments.Comment: Revised version. Accepted for publication in Astronomy and Astrophysics Letters, 5 pages, 3 figure

A functional magnetic resonance imaging study of frontal networks in obsessive-compulsive disorder during cognitive reappraisal

Background Patients with obsessive-compulsive disorder (OCD) present difficulties in the cognitive regulation of emotions, possibly because of inefficient recruitment of distributed patterns of frontal cortex regions. The aim of the present study is to characterize the brain networks, and their dysfunctions, related to emotion regulation alterations observed during cognitive reappraisal in OCD. Methods Adult patients with OCD (n = 31) and healthy controls (HC; n = 30) were compared during performance of a functional magnetic resonance imaging cognitive reappraisal protocol. We used a free independent component analysis approach to analyze network-level alterations during emotional experience and regulation. Correlations with behavioral scores were also explored. Results Analyses were focused on six networks encompassing the frontal cortex. OCD patients showed decreased activation of the frontotemporal network in comparison with HC (F(1,58) = 7.81, p = 0.007) during cognitive reappraisal. A similar trend was observed in the left frontoparietal network. Conclusions The present study demonstrates that patients with OCD show decreased activation of specific networks implicating the frontal cortex during cognitive reappraisal. These outcomes should help to better characterize the psychological processes modulating fear, anxiety, and other core symptoms of patients with OCD, as well as the associated neurobiological alterations, from a system-level perspective