739 research outputs found

    Why do papers from international collaborations get more citations? A bibliometric analysis of Library and Information Science papers

    Get PDF
    Scientific activity has become increasingly complex in recent years. The need for international research collaboration has thus become a common pattern in science. In this current landscape, countries face the problem of maintaining their competitiveness while cooperating with other countries to achieve relevant research outputs. In this international context, publications from international collaborations tend to achieve greater scientific impact than those from domestic ones. To design policies that improve the competitiveness of countries and organizations, it thus becomes necessary to understand the factors and mechanisms that influence the benefits and impact of international research. In this regard, the aim of this study is to confirm whether the differences in impact between international and domestic collaborations are affected by their topics and structure. To perform this study, we examined the Library and Information Science category of the Web of Science database between 2015 and 2019. A science mapping analysis approach was used to extract the themes and their structure according to collaboration type and in the whole category (2015–2019). We also looked for differences in these thematic aspects in top countries and in communities of collaborating countries. The results showed that the thematic factor influences the impact of international research, as the themes in this type of collaboration lie at the forefront of the Library and Information Science category (e.g., technologies such as artificial intelligence and social media are found in the category), while domestic collaborations have focused on more well-consolidated themes (e.g., academic libraries and bibliometrics). Organizations, countries, and communities of countries must therefore consider this thematic factor when designing strategies to improve their competitiveness and collaborate.Spanish Government PID2019-105381GA-I00/AEI/10.13039/50110001103

    Globular Aggregates Stemming from the Self-Assembly of an Amphiphilic N-Annulated Perylene Bisimide in Aqueous Media

    Get PDF
    Herein, we describe the synthesis of highly emissive amphiphilic N-annulated PBI 1 decorated with oligo ethylene glycol (OEG) side chains. These polar side chains allow the straightforward solubility of 1 in solvents of different polarity such as water, iPrOH, dioxane, or chloroform. Compound 1 self-assembles in aqueous media by π-stacking of the aromatic units and van der Waals interactions, favored by the hydrophobic effect. The hypo- and hypsochromic effect observed in the UV-Vis spectra of 1 in water in comparison to chloroform is diagnostic of H-type aggregation. Solvent denaturation experiments allow deriving the free Gibbs energy for the self-assembly process in aqueous media and the factor m that is indicative of the influence exerted by a good solvent in the stability of the final aggregates. The ability of compound 1 to self-assemble in water yields globular aggregates that have been visualized by TEM imaging.Depto. de Química OrgánicaFac. de Ciencias QuímicasTRUEMCIUComunidad de Madridpu

    Nosocomial outbreak of Pseudomonas aeruginosa endophthalmitis

    Get PDF
    We describe an outbreak of nosocomial endophthalmitis due to a common source, which was determined to be trypan blue solution prepared in the hospital's pharmacy service. We assume that viable bacteria probably gained access to the trypan blue stock solution during cooling after autoclaving. The temporal cluster of Pseudomonas aeruginosa endophthalmitis was readily perceived on the basis of clinical and microbiological findings, and an exogenous source of contamination was unequivocally identified by means of DNA fingerprinting. © 2006 by The Society for Healthcare Epidemiology of America. All rights reserved

    Luxación traumática de la rodilla

    Get PDF
    La luxación traumática de la rodilla es la lesión poco frecuente que se asocia a grandes lesiones cápsuloligamentosas y que a menudo afecta a estructuras neurológicas y vasculares. La lesión vascular es la complicación más importante. Todos los autores coinciden en que el diagnóstico precoz y tratamiento urgente de las lesiones de la arteria poplítea son esenciales. Sin embargo, no existe el mismo acuerdo en cuanto al tratamiento de las lesiones cápsuloligamentosas. Algunos autores publican buenos resultados con tratamientos no quirúrgicos, aunque otros consideran que el mejor tratamiento es la reparación completa de las lesiones ligamentosas. Hemos tratado en nuestro hospital siete casos de luxación traumática de rodilla en los últimos 20 años. Presentamos el tratamiento realizado, sus complicaciones y resultados.Traumatic knee dislocation is an uncommon injury associated with extensive soft tissue damage and often neurovascular involvement. Vascular injury is the most serious complication. There is genera agreement that early diagnosis and immediate treatment of popliteal artery disruption is essential. However there is no consensus about treatment of capsular and ligamentous injuries. Some authors reported good results advocated the repair of all ligaments in the best method. Seven traumatic knee dislocations have been treated in our hospital for last 20 years. Initial treatment, complications and results are presented

    Torrential rainfall in northeast of the Iberian Peninsula: synoptic patterns and WeMO influence

    Get PDF
    This study presents a catalogue of synoptic patterns of torrential rainfall in northeast of the Iberian Peninsula (IP). These circulation patterns were obtained by applying a T-mode Principal Component Analysis (PCA) to a daily data grid (NCEP/NCAR reanalysis) at sea level pressure (SLP). The analysis made use of 304 days which recorded >100 mm in one or more stations in provinces of Barcelona, Girona and Tarragona (coastland area of Catalonia) throughout the 1950-2005 period. The catalogue comprises 7 circulation patterns showing a great variety of atmospheric conditions and seasonal or monthly distribution. Likewise, we computed the mean index value of the Western Mediterranean Oscillation index (WeMOi) for the synoptic patterns obtained by averaging all days grouped in each pattern. The results showed a clear association between the negative values of this teleconnection index and torrential rainfall in northeast of the IP. We therefore put forward the WeMO as an essential tool for forecasting heavy rainfall in northeast of Spai

    Theoretical modelling of quaternary GaInAsSb/GaAs self-assembled quantum dots

    Get PDF
    Trabajo presentado al "Quantum Dot", celebrado en Nottingham (UK) del 26 al 30 de Abril de 2010.InAs/GaAs quantum dots exposed to Sb after growth exhibit spectral changes. We study in the present paper an idealized nanostructure consisting of a homogeneous distribution of the quaternary GaInAsSb surrounded by a barrier of GaAs. We nd that the valence band o set is a critical parameter in modelling its electronic structure. Depending on this value, we predict a transition from type-I to type-II band alignment at a di erent Sb concentration. The addition of Sb to reduce the transition energy while keeping a type-I alignment is only of bene t at low Sb concentrationThis work was supported by the Spanish MICINN (projects TEC2008-06756-C03-01/02/TEC, CONSOLIDER INGENIO 2010 CSD2006-0019 and CSD2009-00013), the Junta de Andalucía (PAI research groups TEP-120 and TIC-145; project P08-TEP-03516) and Comunidad Autónoma de Madrid S2009ESP-1503.Peer reviewe

    Direct observation of tunnelled intergrowth in SnO2/Ga2O3 complex nanowires

    Get PDF
    beta-Ga_2O_3 intergrowths have been revealed in the SnO_2 rutile structure when SnO_2/Ga_2O_3 complex nanostructures are grown by thermal evaporation with a catalyst-free basis method. The structure is formed by a Ga_2O_3 nanowire trunk, around which a rutile SnO_2 particle is formed with [001] aligned to the [010] Ga_2O_3 trunk axis. Inside the SnO_2 particle, beta-Ga_2O_3 units occur separated periodically by hexagonal tunnels in the (210) rutile plane. Orange (620 nm) optical emission from tin oxide, with a narrow linewidth indicating localised electronic states, may be associated with this beta-Ga_2O_3 intergrowth

    Aggressive Behavior in School-aged Children: Clusters based on Anger, Empathy and Testosterone and Cortisol Measures

    Get PDF
    The aim of this piece of research was to study the existence of clusters based on anger, empathy and cortisol and testosterone measures associated with aggressive behavior in school-aged children. The sample group comprised 139 eight-year-old children (80 boys and 59 girls). Aggressive behavior was measured using the Direct and Indirect Aggression Scale. Both psychological and biological variables were used to determine psychobiological profiles. The psychological variables considered were trait anger, measured using the State-Trait Anger Expression Inventory for Children and Adolescents, and empathy, measured using the Empathy Quotient-Child Version. Testosterone and cortisol concentrations were measured through saliva samples and analyzed using an ELISA (Enzyme-linked immunosorbent assay). A Cluster Analysis revealed three clusters which were clearly different as regards their psychological and biological characteristics. The analysis of variance (ANOVA) revealed that the cluster characterized by having higher anger levels, lower empathy levels and higher testosterone and cortisol levels was more aggressive than the other two (p < .0001, η2 = .19). The results indicate that studying psychological and biological variables together may help establish differentiated aggression patterns among children

    Artrodesis de rodilla por fracaso de la artroplatsia total

    Get PDF
    Veintiuna artrodesis de rodilla fueron realizadas en nuestro Servicio en los últimos 20 años. Se realiza un estudio retrospectivo con un seguimiento medio de 10 años. Las razones para la artrodesis fueron en 12 ocasiones (57%) infección de la artroplastia total, y en los 9 casos restantes (43%) aflojamiento aséptico. La artrodesis se realizó mediante fijación externa en un solo plano en 11 casos (52%), en biplano se colocó en 7 (33%), 2 casos con placas a compresión (9,5%) y el caso restante mediante un clavo intramedular (5%). La fusión después del procedimiento inicial se obtuvo solamente en 12 pacientes (57%) y añadiendo procedimientos adicionales totalizamos 19 rodillas fusionadas (90%). Las complicaciones encontradas fueron: 9 pseudoartrosis, 2 infecciones en el trayecto de las fichas, 2 roturas del material de fijación, una infección persistente que llevó a la amputación, y una parálisis del nervio ciático poplíteo externo.A total of 21 knee arthrodesis performed in the last 20 years was reviewed with an average follow-up of 10 years. Arthrodesis was performed following deep infection in 12 cases (57%) and aseptic loosening of the prostheses in the remaining 9 cases. TH artrodesis were performed using one-plane external fixation in 11 cases, two-planes external fixation in 7, compression plates in 2, intramedular nailing in only 12 patients. Using additional procedures we obtained 19 fused knees (90 %). The complications in this series were: Psuedarthrosis (9 cases), infection of the fixator pins (2 cases), infection of the fixator pins (2 cases), and broken osteosybrtesis components (2 cases), severe deep infection with final amputation of the limb (1 case), and CPE injury (1 case)

    Epitaxial growth of SrTiO3 films on cube-textured Cu-clad substrates by PLD at low temperature under reducing atmosphere

    Get PDF
    The growth of epitaxial {001} SrTiO3 (STO) on low-cost cube-textured Cu-based clad substrate at low temperature was carried out by means of pulsed laser deposition (PLD). STO film was deposited in one step under a reducing atmosphere (5% H2 and 95% Ar mixture) to prevent the oxidation of the metal surface. The optimization of PLD parameters leads to a sharpest biaxial texture at a temperature as low as 500 °C and a thickness of 500 nm with a (100) STO layer. The upper limit of highly textured STO thickness was also investigated. The maximum thickness which retains the best quality {001} texture is 800 nm, since the texture is preserved not only through the layer but also on the surface. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) measurements showed that STO films are continuous, dense, and smooth with very low roughness (between 5 and 7 nm). This paper describes the development of STO layer by means of PLD in absence of oxygen throughout the process, suggesting an alternative and effective method for growing highly {001} textured STO layer on low-cost metal substrates
    corecore