1,290 research outputs found

    {\it Ab initio} 27Al^{27}Al NMR chemical shifts and quadrupolar parameters for Al2O3Al_2O_3 phases and their precursors

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    The Gauge-Including Projector Augmented Wave (GIPAW) method, within the Density Functional Theory (DFT) Generalized Gradient Approximation (GGA) framework, is applied to compute solid state NMR parameters for 27Al^{27}Al in the α\alpha, θ\theta, and κ\kappa aluminium oxide phases and their gibbsite and boehmite precursors. The results for well-established crystalline phases compare very well with available experimental data and provide confidence in the accuracy of the method. For γ\gamma-alumina, four structural models proposed in the literature are discussed in terms of their ability to reproduce the experimental spectra also reported in the literature. Among the considered models, the Fd3ˉmFd\bar{3}m structure proposed by Paglia {\it et al.} [Phys. Rev. B {\bf 71}, 224115 (2005)] shows the best agreement. We attempt to link the theoretical NMR parameters to the local geometry. Chemical shifts depend on coordination number but no further correlation is found with geometrical parameters. Instead our calculations reveal that, within a given coordination number, a linear correlation exists between chemical shifts and Born effective charges

    Deterministic and probabilistic dietary exposure assessment to deoxynivalenol in Spain and the Catalonian region

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    Deoxynivalenol (DON) remains one of the most concerning mycotoxins produced by the Fusarium genus due to the wide occurrence in highly consumed cereal-based food and its associ-ated toxicological effects. Previous studies conducted in Spain and other European countries suggested that some vulnerable groups such as children could be exceeding the tolerable daily intakes. Thus, the aim of this study was to conduct a comprehensive and updated dietary expo-sure assessment study in Spain, with a specific analysis in the region of Catalonia. Cereal-based food samples collected during 2019 were analysed using liquid chromatography coupled to tan-dem mass spectrometry for multi-mycotoxin detection including DON and its main metabolites and derivatives. Consumption data were gathered from the nation-wide food surveys ENALIA and ENALIA2 conducted in Spain, and a specific survey conducted in Catalonia. The data were combined using deterministic and semi-parametric probabilistic methods. The results showed that DON was widely present in cereal-based food highly consumed in Spain and the Catalonia region. Exposure to DON among the adult population was globally low; however, among in-fants aged 3-9 years, it resulted in the median of 192 ng/kg body weight/day and the 95th per-centiles of 604 ng/kg body weight/day, that would exceed the most conservative safety threshold for infants. Bread and pasta were the main contributing foodstuffs to the global exposure to DON, even among infants; thus, those foods should be considered a priority for food control or to develop strategies to reduce the exposure. In any case, further toxicological and epidemiolog-ical studies are required in order to refine the safety thresholds accounting for the sensitivity of the infant population.This research was funded by the Catalan Agency of Food Safety (ACSA) (SA-2019-391) and the Agency for Management of University and Research Grants (AGAUR) with a doctoral fellowship (2021 FI_B 00129; 2022 FI_B1 00033)

    The order parameter-entropy relation in some universal classes: experimental evidence

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    The asymptotic behaviour near phase transitions can be suitably characterized by the scaling of Δs/Q2\Delta s/Q^2 with ϵ=1T/Tc\epsilon=1-T/T_c, where Δs\Delta s is the excess entropy and QQ is the order parameter. As Δs\Delta s is obtained by integration of the experimental excess specific heat of the transition Δc\Delta c, it displays little experimental noise so that the curve log(Δs/Q2)\log(\Delta s/Q^2) versus logϵ\log\epsilon is better constrained than, say, logΔc\log\Delta c versus logϵ\log\epsilon. The behaviour of Δs/Q2\Delta s/Q^2 for different universality classes is presented and compared. In all cases, it clearly deviates from being a constant. The determination of this function can then be an effective method to distinguish asymptotic critical behaviour. For comparison, experimental data for three very different systems, Rb2CoF4, Rb2ZnCl4 and SrTiO3, are analysed under this approach. In SrTiO3, the function Δs/Q2\Delta s/Q^2 does not deviate within experimental resolution from a straight line so that, although Q can be fitted with a non mean-field exponent, the data can be explained by a classical Landau mean-field behaviour. In contrast, the behaviour of Δs/Q2\Delta s/Q^2 for the antiferromagnetic transition in Rb2CoF4 and the normal-incommensurate phase transition in Rb2ZCl4 is fully consistent with the asymptotic critical behaviour of the universality class corresponding to each case. This analysis supports, therefore, the claim that incommensurate phase transitions in general, and the A2_2BX4_4 compounds in particular, in contrast with most structural phase transitions, have critical regions large enough to be observable.Comment: 13 pp. 9 ff. 2 tab. RevTeX. Submitted to J. Phys.: Cond. Matte

    Antimalarial activity of cupredoxins: the interaction of Plasmodium Merozoite Surface Protein 119 (MSP119) and Rusticyanin

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    Background: The interaction of MSP119 with the cupredoxin azurin inhibits the growth of Plasmodium falciparum in red blood cells. Results: Rusticyanin forms a well-defined complex with MSP119 upon binding at the same surface area than inhibitory antibodies. Conclusion: Rusticyanin becomes an excellent therapeutic agent for malaria. Significance: Knowing the rusticyanin- MSP119 interface will allow the design of novel anti-malarial drugsJunta de Andalucía P08-CVI-3876, BIO198Ministerio de Economía y Competitividad SAF2011- 26611Fundación Séneca de la Región de Murcia 15354/PI/10Ministerio de Ciencia e Innovación BFU2010-19451Medical Research Council U117574558, U11753206

    Homeopathic Perovskite Solar Cells: Effect of Humidity during Fabrication on the Performance and Stability of the Device

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    Rapid degradation in humid environments is a major drawback of methylammonium lead iodide (CH3NH3PbI3), which is the archetypical component of perovskite solar cells. In this work, we have investigated the aging and degradation kinetics of CH3NH3PbI3 films and devices fabricated under controlled conditions as a function of relative humidity (RH) and compared their performance with those that were prepared under dry conditions. The aging and degradation kinetics is monitored by optical absorption and impedance spectroscopy measurements under monochromatic illumination at two different wavelengths. Aged devices show a substantial difference between the recombination rate under red and blue light illumination, which is attributed to the enhancement of local recombination routes upon aging. Interestingly, we observe that this feature is less pronounced in devices prepared under conditions of the highest RH of 50%. In general, we found that these devices keep their original electric properties and withstand a humid environment better. Chemical analysis by X-ray photoelectron spectroscopy reveals the presence of coordinating water in the CH3NH3PbI3 crystalline structure. This indicates that the presence of a small amount of water has a beneficial effect against degradation in a humid environment

    CLINICAL EVALUATION OF Paragonimiosis IN CATS EXPERIMENTALLY INFECTED WITH Paragonimus mexicanus

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    El objetivo del presente estudio fue describir signos clínicos asociados con lainfección experimental con Paragonimus mexicanus en gatos. Se emplearon ocho gatos de 2.5 a 4 meses de edad, que fueron infectados con 7 a 20 metacercarias por vía oral. En el examen físico durante la fase aguda se encontró aumento de la temperatura corporal, cuadros de tos productiva y un aumento de tamaño del nódulo linfático inguinal, y en la fase crónica cuadros de tos productiva, reflejo traqueal positivo y aumento del murmullo vesicular. En el hemograma se encontró leucocitosis con grados variables de linfocitosis, neutrofilia y eosinofilia en la fase aguda, y leucocitosis poraumento de eosinófilos en la fase crónica. A través de la ecografía abdominal se encontró engrosamiento de la pared vesicular, esplenomegalia, hepatomegalia y aumento de ecogenicidad hepática, especialmente durante la fase aguda. Los hallazgos radiológicos tempranos incluyeron focos de bronquiectasia y de engrosamiento bronquial y aumento de radiopacidad de lóbulos pulmonares, y en etapas posteriores se observaron estructuras radiopacas ovoides en parénquima pulmonar y bronquiectasia. El periodo entre la inoculación de las metacercarias hasta la observación de huevos de P. mexicanusen heces fue de 41 a 70 días. En la necropsia se confirmó la presencia de quistes y parásitos a nivel pulmonar.The objective of this study was to describe the clinical signs associated to theexperimental infection of Paragonimus mexicanus in cats. Eight cats of 2.5 to 4 months ofage were orally infected with 7 to 20 metacercariae. In the physical examination during theacute phase was found fever, wet cough, and enlargement of the inguinal lymph node,while in the chronic phase wet cough, positive tracheal reflex and increase of the breathsound. On the complete blood count was found leukocytosis with different degrees oflymphocytosis, neutrophilia and eosinophilia in the acute phase and leukocytosis withan increase of eosinophilia in the chronic phase. On the ultrasonography examination,enlargement of the vesicular wall, hepatomegaly, splenomegaly and increase in liverechogenicity were found, especially during the acute phase. The early radiological findingsincluded bronchiectasis focus, bronchial thickening and increased radiopacity of lunglobes, while in the chronic phase radiopaque ovoid structures in the pulmonary parenchymaand bronchiectasis were observed. The period between infection and presence of P.mexicanus eggs in the faeces was between 41 and 71 days. The necropsy confirmed thepresence of cysts and parasites in the lungs

    Heterometallic titanium–gold complexes inhibit renal cancer cells in vitro and in vivo

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    Following recent work on heterometallic titanocene–gold complexes as potential chemotherapeutics for renal cancer, we report here on the synthesis, characterization and stability studies of new titanocene complexes containing a methyl group and a carboxylate ligand (mba ¼ S–C6H4–COO) bound to gold(I)-phosphane fragments through a thiolate group [(h-C5H5)2TiMe(m-mba)Au(PR3)]. The compounds are more stable in physiological media than those previously reported and are highly cytotoxic against human cancer renal cell lines. We describe here preliminary mechanistic data involving studies on the interaction of selected compounds with plasmid (pBR322) DNA used as a model nucleic acid, and with selected protein kinases from a panel of 35 protein kinases having oncological interest. Preliminary mechanistic studies in Caki-1 renal cells indicate that the cytotoxic and anti-migration effects of the most active compound 5 [(h-C5H5)2TiMe(m-mba)Au(PPh3)] involve inhibition of thioredoxin reductase and loss of expression of protein kinases that drive cell migration (AKT, p90-RSK, and MAPKAPK3). The co-localization of both titanium and gold metals (1 : 1 ratio) in Caki-1 renal cells was demonstrated for 5 indicating the robustness of the heterometallic compound in vitro. Two compounds were selected for further in vivo studies on mice based on their selectivity in vitro against renal cancer cell lines when compared to non-tumorigenic human kidney cell lines (HEK-293T and RPTC) and the favourable preliminary toxicity profile in C57BL/6 mice. Evaluation of Caki-1 xenografts in NOD.CB17-Prkdc SCID/J mice showed an impressive tumor reduction (67%) after treatment for 28 days (3 mg per kg per every other day) with heterometallic compound 5 as compared with the previously described [(h-C5H5)2Ti {OC(O)-4-C6H4-P(Ph2)AuCl}2] 3 which was non-inhibitory. These findings indicate that structural modifications on the ligand scaffold affect the in vivo efficacy of this class of compounds

    High intensity efforts during competition in professional football

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    The aim, of this work was to quantify the number and duration of the very high-speed running and sprinting events (VHSRS) and the recovery interval between them in 36 first and second division professional soccer players. The players were monitored through GPS devices during two official matches. The average duration of the EMAVS was 2.58 ± 0.44 seconds with an average interval between them of 107.07 ± 67.00 s. The mean heart rate (HR) during the EMAVS was 164.92 ± 12.39 p.p.m., reaching 85% of the maximum HR. No significant differences were found between the duration of the VHSRS, the intervals between them and the HR reached (p≤0.05 in all cases), with great individual variability. The use of the duration of the EMAVS, the recovery times and the HR reached during them, would be very useful to design the interval training in football.El objetivo de este trabajo fue cuantificar el número y duración de los esfuerzos de muy alta intensidad y esprint (EMAVS) y el intervalo de recuperación entre ellos en 36 futbolistas profesionales de primera y de segunda división. Los jugadores fueron monitorizados a través de dispositivos GPS durante dos partidos oficiales. La duración promedio de los EMAVS fue de 2,58±0,44 segundos con un intervalo medio entre los mismos de 107,07±67,00 sg. La FC media durante los EMAVS se situó en 164,92±12,39 p.p.m., alcanzando el 85% de la FC máxima. No se encontraron diferencias significativas entre la duración de los EMAVS, los intervalos entre ellos y la FC alcanzada (p≤ 0,05 en todos los casos), con gran variabilidad individual. La utilización de la duración de los EMAVS, los tiempos de recuperación y la FC alcanzada durante los mismos, serían de gran utilidad para diseñar los entrenamientos interválicos en el fútbo
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