24 research outputs found

    Imido complexes of vanadium

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    Imido ligands have been widely used as stabilizing ligands in highoxidationstate transition metal complexes. Their chemistry has experienced a remarkable growth due to the role they play in many important reactions. Following our interest in this area, we have extended our recent results in the synthesis of bis(imido) complexes of molybdenum, d0Mo( NR)2, to the related d0 organoimido complexes of vanadium. In this contribution, we describe the synthesis and characterization of several complexes of vanadium containing the imido ligand

    Added value of assimilating springtime Arctic sea ice concentration in summer-fall climate predictions

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    Prediction skill of continental climate in the Northern Hemisphere (NH) midlatitudes is generally limited throughout the year in dynamical seasonal forecast systems. Such limitations narrow the range of possible applications by different stakeholders. Improving the predictive capacity in these regions has been a challenging task. Sea ice is a central component of the Arctic climate system and a local source of climate predictability, yet its state is often not fully constrained in dynamical forecast systems. Using the EC-Earth3 climate model, we study the added value of assimilating observed Arctic sea ice concentration on the NH extratropical climate in retrospective forecasts of summer and fall, initialized every spring over 1992–2019. Predictions in the North Atlantic and Eurasia benefit from better initialization of sea ice in the Atlantic sector of the Arctic in a two-step mechanism. Initially, sea ice influences the central North Atlantic Ocean through an atmospheric bridge that develops in the first forecast weeks, subsequently leading to preserved skill in the sea surface temperatures (SSTs) throughout summer and early fall. Secondly, these long-lasting SST improvements provide better surface boundary conditions for the atmosphere and lead to more skillful predictions of circulation and surface climate in the Euro-Atlantic and Asian regions. In addition, our findings suggest that fully coupled ocean-atmosphere-sea ice models are likely necessary to study linkages between Arctic sea ice and midlatitudes, by better representing the interactions and feedbacks between the different components of the climate system.The data that support the findings of this study are available upon reasonable request from the authors. This work was funded by the European Union projects APPLICATE (Grant 727862), INTAROS (Grant 727890), and ESA/CMUG-CCI3. J C A N received financial support from the Spanish Ministerio de Ciencia, Innovación y Universidades through a Juan de la Cierva personal grant (FJCI-2017-34027). J G-S was supported by the Spanish 'Ramón y Cajal' programme (RYC-2016-21181). All the data were downloaded from their original source, converted to NetCDF in a format designed for efficient analysis and quality checked at several levels. Etienne Tourigny, Pierre-Antoine Bretonnière, Margarida Samsó Cabré, Núria Pérez Zanón and An Chi Ho are acknowledged for their help with technical aspects. We thank the two anonymous reviewers for their valuable comments on the manuscript.Peer ReviewedPostprint (published version

    Efficacy of Nutritional Strategies on the Improvement of the Performance and Health of the Athlete: A Systematic Review

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    Evidence shows that the use of food strategies can impact health, but a clear consensus about how the effects of different food strategies impact improvement in the athlete’s performance and health remain unclear. This study evaluated how food strategies, specifically intermittent fasting and a ketogenic diet affect health and performance in healthy athletes. Study selection for this review was based on clinical trial studies analyzing changes in performance and health in athletes. The Pubmed, Web of Science, PEDro, Dialnet, Scopus, CINAHL, ProQuest, Medline and Cochrane databases were searched. The Physiotherapy Evidence Database (PEDro) scale, PEDro Internal Validity Scale (IVS) and Standard Quality Assessment Criteria for Evaluating Primary Research Papers from a variety of fields (QUALSYT) checklists were used to evaluate the risk of bias of the included studies. Articles were selected based on criteria concerning the effectiveness of nutritional strategies on athletes’ performance; articles should be randomized clinical trials (RCTs) or uncontrolled clinical trials; they should be human studies and they should have been published less than 7 years ago. A total of 15 articles were evaluated, 8 randomised clinical trials and 7 non-randomized clinical studies, with 411 participants who satisfied our inclusion criteria and were included in this review. The results of the study showed intermittent fasting and time-restricted feeding as strategies that produce health benefits. On the other hand, the ketogenic diet did not reach an appropriate consensus. The articles presented a medium level of methodological quality in the PEDro scale, low quality in IVS scale and high quality in QUALSYT scale. Despite the lack of studies analyzing changes in the performance and health of athletes after the use of different nutritional strategies, intermittent fasting and time-restricted feeding should be considered since they seem to be effective, and further studies are necessary

    Influence of N-donor bases and the solvent in oxodiperoxomolybdenum catalysed olefin epoxidation with hydrogen peroxide in ionic liquids

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    Biphasic catalytic olefin epoxidation systems consisting of oxodiperoxomolybdenum catalysts in 1- n -alkyl-3-methylimidazolium hexafluorophosphate ionic liquid (IL) media with aqueous hydrogen peroxide oxidant were optimised by tuning the molecular structure of the IL and employing N -heterocyclic donor base additives to inhibit hydrolysis and enhance the activity of the catalyst. The latter study was only made possible by the solubilising properties of the IL media. Of the bases investigated, pyrazoles were identified as the most efficient additive species and the best results were obtained using 3,5-dimethylpyrazole. Immobilisation of the catalyst in the IL allowed for very efficient catalyst recycling. Finally, the compound [MoO(O 2 ) 2 (3-Mepz) 2 ](3-Mepz = 3-methylpyrazole) was characterised and its structure determined by X-ray crystallography

    Efficacy of Photobiomodulation Therapy in the Treatment of Pain and Inflammation: A Literature Review

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    The main objective of this literature review was to analyze the efficacy of (PBM) therapy application on subjects with chronic pain and inflammation, and furthermore, to evaluate the methodological quality of the collected literature. The search was conducted using five databases: PubMed, ProQuest, Scopus, Web of Science, and PEDro. The keywords “low level laser therapy”, “chronic pain”, and “inflammation” provided the selection of RCTs that were published within the last 5 years, conducted in humans, and written in English. The PEDro Internal Validity Scale (IVS) checklist was used to evaluate the risk of bias in the included studies. A total of 11 articles were selected, all of them RCTs. Of the articles, five showed that PBM positively influences chronic pain, while another showed the same but only in the short term. In two other articles, the patient’s inflammation improved markedly. In one article there was no improvement in chronic pain and in another, there was no improvement in inflammation. Four articles demonstrated that PBM is beneficial in acute pain. Furthermore, six studies were given an “excellent” score and the remaining five a “good” score based on the IVS. Photobiomodulation has beneficial effects on chronic pain and inflammation, although more research needs to be completed in this line for this to be clarified as the existence of RCTs on this subject is limited.University Chair in Clinical Psychoneuroimmunology (University of Granada and PNI Europe

    Red de seguimiento y coordinación del Máster en Ciencia de Materiales

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    El Máster en Ciencia de Materiales se imparte en la Facultad de Ciencias de la Universidad de Alicante, consta de 60 créditos ECTS que se cursan durante 1 año académico. El máster está implantado desde el curso 2010-2011 por lo que durante el actual curso 2014-2015 tendremos la quinta promoción de egresados. La red docente está formada por la comisión académica del Máster en Ciencia de Materiales. Esta comisión (profesorado, alumno y personal de administración y servicios) lleva realizando un seguimiento de la titulación durante los 4 cursos anteriores. Por tanto la red tiene como objetivo principal el seguimiento, coordinación, evaluación y mejora de la planificación realizada con las experiencias recogidas a lo largo de estos años. Además, se realizará un estudio de los diferentes indicadores de calidad que utilizan las agencias de acreditación puesto que este año el Máster se someterá a la renovación de la acreditación

    Efficacy of photobiomodulation therapy in the treatment of pain and inflammation: a literature review

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    The main objective of this literature review was to analyze the efficacy of (PBM) therapy application on subjects with chronic pain and inflammation, and furthermore, to evaluate the methodological quality of the collected literature. The search was conducted using five databases: PubMed, ProQuest, Scopus, Web of Science, and PEDro. The keywords “low level laser therapy”, “chronic pain”, and “inflammation” provided the selection of RCTs that were published within the last 5 years, conducted in humans, and written in English. The PEDro Internal Validity Scale (IVS) checklist was used to evaluate the risk of bias in the included studies. A total of 11 articles were selected, all of them RCTs. Of the articles, five showed that PBM positively influences chronic pain, while another showed the same but only in the short term. In two other articles, the patient’s inflammation improved markedly. In one article there was no improvement in chronic pain and in another, there was no improvement in inflammation. Four articles demonstrated that PBM is beneficial in acute pain. Furthermore, six studies were given an “excellent” score and the remaining five a “good” score based on the IVS. Photobiomodulation has beneficial effects on chronic pain and inflammation, although more research needs to be completed in this line for this to be clarified as the existence of RCTs on this subject is limited.This study has been partially funded by the University Chair in Clinical Psychoneuroimmunology (University of Granada and PNI Europe). Partial funding for open access charge: Universidad de Málag

    Calathus: A sample-return mission to Ceres

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    Ceres, as revealed by NASA's Dawn spacecraft, is an ancient, crater-saturated body dominated by low-albedo clays. Yet, localised sites display a bright, carbonate mineralogy that may be as young as 2 Myr. The largest of these bright regions (faculae) are found in the 92 km Occator Crater, and would have formed by the eruption of alkaline brines from a subsurface reservoir of fluids. The internal structure and surface chemistry suggest that Ceres is an extant host for a number of the known prerequisites for terrestrial biota, and as such, represents an accessible insight into a potentially habitable “ocean world”. In this paper, the case and the means for a return mission to Ceres are outlined, presenting the Calathus mission to return to Earth a sample of the Occator Crater faculae for high-precision laboratory analyses. Calathus consists of an orbiter and a lander with an ascent module: the orbiter is equipped with a high-resolution camera, a thermal imager, and a radar; the lander contains a sampling arm, a camera, and an on-board gas chromatograph mass spectrometer; and the ascent module contains vessels for four cerean samples, collectively amounting to a maximum 40 g. Upon return to Earth, the samples would be characterised via high-precision analyses to understand the salt and organic composition of the Occator faculae, and from there to assess both the habitability and the evolution of a relict ocean world from the dawn of the Solar System.The attached document is the authors’ final accepted version of the journal article provided here with a Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) Creative Commons Licence. You are advised to consult the publisher’s version if you wish to cite from it.

    Design of high compression point josephson junction travelling wave parametric amplifiers for readout of millimetre and sub-millimetre astronomical receivers

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    Supra-THz heterodyne mixers generally have higher conversion loss compared to the millimetre-wave mixers. Hence, the overall receiver noise temperature becomes increasingly dominated by the first-stage semiconductor low noise amplifier (LNA), which still struggles to achieve quantum-limited noise performance. Here, we aim to develop a Josephson junction travelling wave parametric amplifier (JTWPA) that can achieve high gain over broad bandwidth but with better noise performance to replace these Intermediate Frequency (IF) amplifiers. JTWPAs are typically considered not suitable for astronomical receivers due to their low power handling capability. However, the critical current of the Josephson junctions (JJ) can be easily engineered to match the output power of the front-end detectors. Nevertheless, this may results in the requirement of a higher number of JJs as the junction inductance is in reverse relation with the critical current. Therefore, in this paper, we aim to explore the different design parameters required for developing a JTWPA with a dynamic range compatible for readout a Superconductor-Insulator-Superconductor (SIS) mixer, as an example. Here, we present two JTWPA models that are suitable for the objective, one requiring 3,142 Nb/Al-AlOx/Nb junctions with a maximum gain of 23 dB, and the other with a lower gain at 16 dB but requires only 1,317 JJs. We then compare the SIS receiver noise performance utilising these JTWPAs with that of using a conventional high gain High Electron Mobility Transistor (HEMT) amplifier. We show that we can improve the receiver sensitivity significantly by either cascading two 23 dB gain JTWPA or using a combination of a 16 dB gain JTWPA and a HEMT amplifier. We conclude that the former option more suitable for large detector array applications as it completely replaces the high heat dissipation HEMT amplifiers; while the latter option is favourable at this stage for low pixel count application as it is easier to fabricate a lower number of junctions JTWPA

    Análisis de flujos turbulentos mediante simulación numérica

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    Este trabajo se centra en el estudio y simulación de flujos turbulentos con aplicación a problemas de interés en el campo de la física de la atmósfera. El objetivo principal de este trabajo es analizar el comportamiento de diferentes modelos ILES novedosos, basados en esquemas numéricos en volúmenes finitos de muy alto orden, y extraer conclusiones sobre la resolución espectral de los mismos analizando su difusión numérica y otras propiedades relevantes.<br /
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