6,738 research outputs found

    Evaluation of Solvent Efficacy of the Myrciaria Dubia (Camu-camu) Essential Oil in Root Canal Re-treatment Procedures: An In Vitro Study

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    Aim: To evaluate the solvent efficacy of an experimental substance based on the Myrciaria dubia (camu-camu) essential oil in root canal re-treatment procedures. Materials and methods: Sixty polylactic acid tubes (PLA) were used and divided into five groups (distilled water, M. dubia oil (camu-camu), xylene, orange peel, and eucalyptus oil). In each group, 12 tubes were filled with a temporary restorative material (Coltosol®). The upper and the middle part were filled with gutta-percha. A total of 0.1 mL solvent was added depending on the study group and left for 5 minutes. Once the solvent was placed, the samples were taken to the Instron 3382 machine. The force used to penetrate the spreader into the 5 mm depth was recorded in Newton (N). The Kruskal–Wallis test and Dunn’s post hoc test were used for multiple comparisons (p < 0.05). Statistical analysis was performed using Stata® v.15.0 package. Results: We found significant statistical differences when comparing all solvents (p = 0.001), obtaining 14.02 N for the experimental substance. The results of the superficial dissolution depth and the force used to penetrate the spreader to 5 mm revealed that the M. dubia oil (camu-camu) was the solvent that significantly softened the gutta-percha the most (p < 0.05). These values were followed by xylene and orange peel oil. We also found that the solvent with the lowest efficacy was eucalyptus oil. Conclusion: The M. dubia (camu-camu) essential oil had more softening power than other solutions in the study. Clinical significance: The efficacy of the M. dubia (camu-camu) essential oil is relevant as it is a nonharmful solvent that would not harm the periapical tissue and would reduce the time of endodontic re-treatments procedures, which is beneficial for patients.Revisión por pare

    A 0535+26: an X-ray/Optical Tour

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    We compiled X-ray and Optical observations of the accreting X-ray binary system A 0535+262 since its discovery in 1975, that will allow us to shed light on the unpredictable behavior of this binary system. We present the data in terms of the Be-disk interaction with the neutron star companion. In addition, we show recent results from the continuous monitoring of this source by the Gamma-ray Burst Monitor(GBM), on board the Fermi observatory, since its launch in 2008 June 11.Comment: 4 pages, 5 figures, Conference proceeding of "Astrophysics of Neutron Stars 2010 - a conference in honor of M. Ali Alpar", 2-6 August 2010, Cesme, Izmir, Turke

    Redox and Catalytic Properties of Promoted NiO Catalysts for the Oxidative Dehydrogenation of Ethane

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    [EN] NiO and metal-promoted NiO catalysts (M-NiO, with a M/(M+Ni) atomic ratio of 0.08, with M = Nb, Sn, or La) have been prepared, tested in the oxidative dehydrogenation (ODH) of ethane, and characterized by means of XRD, TPR, HRTEM, Raman, XPS, and in situ XAS (using H-2/He, air or C2H6/He mixtures). The selectivity to ethylene during the ODH of ethane decreases according to the following trend: Nb NiO Sn NiO > La NiO > NiO, whereas the catalyst reducibility (determined by both TPR and XAS using H-2/He mixtures) shows the opposite trend. However, different reducibility and catalytic behavior in the absence of oxygen (ethane/He mixtures) have been observed, especially when comparing Nb- and Sn-promoted NiO samples. These differences can be ascribed mainly to a different phase distribution of the promoter. The results presented here are discussed in terms of the nature of active and selective sites for ODH of ethane in selective and unselective catalysts, but also the role of promoters and the importance of their phase distribution.The authors would like to acknowledge the DGICYT in Spain CTQ2012-37925-C03-2, CTQ2015-68951-C3-1-R, and CTQ2015-68951-C3-3-R. Authors thank European Synchrotron Radiation Facility, ESRF (Project CH-4512; BM25-SpLine Beamlime). Authors from ITQ also thank Project SEV-2016-0683 for financial support. D.D. thanks MINECO and Severo Ochoa Excellence Program for his fellowship (SVP-2014-068669). B.S. also thanks UV-INV-AE16-484416. Finally, the authors thank the Electron Microscopy Service of Universitat Politecnica de Valencia for their support.Delgado-Muñoz, D.; Solsona Espriu, BE.; Ykrelef, A.; Rodriguez-Gomez, A.; Caballero, A.; Rodríguez-Aguado, E.; Rodriguez-Castellón, E.... (2017). Redox and Catalytic Properties of Promoted NiO Catalysts for the Oxidative Dehydrogenation of Ethane. The Journal of Physical Chemistry C. 121(45):25132-25142. https://doi.org/10.1021/acs.jpcc.7b07066S25132251421214

    First simultaneous multi-wavelength observations of the black hole candidate IGR J17091-3624: ATCA, INTEGRAL, Swift, and RXTE views of the 2011 outburst

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    We present the results of the first four (quasi-)simultaneous radio (ATCA), X-ray (Swift, RXTE), and Gamma-ray (INTEGRAL) observations of the black hole candidate IGR J17091-3624, performed in February and March 2011. The X-ray analysis shows that the source was in the hard state, and then it transited to a soft intermediate state. We study the correlated radio/X-ray behaviour of this source for the first time. The radio counterpart to IGR J17091-3624 was detected during all four observations with the ATCA. In the hard state, the radio spectrum is typical of optically thick synchrotron emission from a self-absorbed compact jet. In the soft intermediate state, the detection of optically thin synchrotron emission is probably due to a discrete ejection event associated with the state transition. The position of IGR J17091-3624 in the radio versus X-ray luminosity diagram (aka fundamental plane) is compatible with that of the other black hole sources for distances greater than 11 kpc. IGR J17091-3624 also appears as a new member of the few sources that show a strong quenching of radio emission after the state transition. Using the estimated luminosity at the spectral transition from the hard state, and for a typical mass of 10 M_sun, we estimate a distance to the source between ~11 and ~17 kpc, compatible with the radio behaviour of the source.Comment: 6 pages, 4 figures, 1 online table, accepted for publication in A&

    SHARDS: Constraints on the dust attenuation law of star-forming galaxies at z~2

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    We make use of SHARDS, an ultra-deep (<26.5AB) galaxy survey that provides optical photo-spectra at resolution R~50, via medium band filters (FWHM~150A). This dataset is combined with ancillary optical and NIR fluxes to constrain the dust attenuation law in the rest-frame NUV region of star-forming galaxies within the redshift window 1.5<z<3. We focus on the NUV bump strength (B) and the total-to-selective extinction ratio (Rv), targeting a sample of 1,753 galaxies. By comparing the data with a set of population synthesis models coupled to a parametric dust attenuation law, we constrain Rv and B, as well as the colour excess, E(B-V). We find a correlation between Rv and B, that can be interpreted either as a result of the grain size distribution, or a variation of the dust geometry among galaxies. According to the former, small dust grains are associated with a stronger NUV bump. The latter would lead to a range of clumpiness in the distribution of dust within the interstellar medium of star-forming galaxies. The observed wide range of NUV bump strengths can lead to a systematic in the interpretation of the UV slope (β\beta) typically used to characterize the dust content. In this study we quantify these variations, concluding that the effects are Δβ\Delta\beta~0.4.Comment: 13 pages, 11+2 figures, 3 tables. MNRAS, in pres

    Phenolic profile and physicochemical characterization of quince (Cydonia oblonga Mill) fruits at different maturity index

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    The ripening of fruits is a determinant factor on the composition of phytochemical compounds such as phenolic compounds. In this study the phenolic profile of quince fruits was determined as a function of its maturity index. Based on the total soluble solids (TSS) and the acidity (TA) of the fruits, four maturity indexes were established (12.55, 14.56, 21.86 and 24.77), using the ratio of TSS/TA. The phenolic profile of quince fruits with different maturity indexes were obtained by a reversed-phase HPLC-DAD and HPLC-DAD/MS. A PCA loading plot was generated to explain the relationship between physicochemical parameters and the phenolic compounds. The phenolic compounds identified in the quince fruits were 3-0-caffeoylquinic acid, catechin, 4-0-caffeoylquinic acid, 5-0-caffeoylquinic acid, coumaric acid, quercetin-3-0-rutinoside and quercetin-3-0-glycosides. The maturity index increase caused in general a reduction of phenolic compounds, these compounds were also influenced by pH and acidity of fruits. Quince is a valuable source of natural phenolic antioxidants, and can be used as raw material to elaborate diverse food products, providing important functional properties

    Hyperacute Incidental Late Myocardial Enhancement in Ischemic Stroke Using Chest Spectral CT: Relationship with Etiology

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    Background: Hyperacute cardiac imaging of patients with acute ischemic stroke (AIS), though desirable, is impractical. Using delayed-enhancement, low-dose, non-gated, chest spectral computed tomography scans (DESCT), we explored the prevalence and patterns of incidental myocardial late iodine enhancement (LIE) and embolic sources, and their relationship with stroke etiology. Methods: Since July 2020, DESCT was performed after cerebrovascular CT angiography (CTA) among patients with suspected AIS undergoing CT using a dual-layer spectral scanner, without additional contrast administration. Images were analyzed using monoenergetic reconstructions and iodine density maps, and the myocardial extracellular volume fraction (ECV, %) was calculated. Results: Eighty patients with AIS were included. DESCT identified a cardiac thrombi in 6 patients (7.5%), and a complex aortic plaque in 4 (5%) cases; reclassifying 5 embolic strokes of uncertain source (28% of ESUS) to cardioembolic (CE, n = 3) and non-CE (n = 2) etiologies. LIE was identified in 38 (48%) patients, most commonly (82%) of ischemic pattern. We did not identify significant relationships between AIS etiology and the presence, pattern, and extent of LIE (p > 0.05); ECV (p = 0.56), severe aortic (p = 0.25) or valvular (p = 0.26) disease, or the extent of coronary calcification (p = 0.39). Patients with evidence of major cardiovascular DESCT findings had higher rates of all-cause death at 90 days (42% vs. 19%, p = 0.037). Conclusions: In this study, hyperacute cardiac imaging of AIS with DESCT identified a high prevalence of incidental cardiac disease predominantly involving LIE of ischemic etiology and mostly not related to the stroke etiology.Fil: Rodriguez Granillo, Gaston Alfredo. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto Alberto C. Taquini de Investigaciones en Medicina Traslacional - Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones CardiolĂłgicas "Prof. Dr. Alberto C. Taquini". Instituto Alberto C. Taquini de Investigaciones en Medicina Traslacional; Argentina. Clinica La Sagrada Familia. Instituto Medico ENERI; ArgentinaFil: Cirio, Juan J.. Clinica La Sagrada Familia. Instituto Medico ENERI; ArgentinaFil: Ciardi, Celina. Clinica La Sagrada Familia. Instituto Medico ENERI; ArgentinaFil: Caballero, Maria L.. Clinica La Sagrada Familia. Instituto Medico ENERI; ArgentinaFil: Fontana, Lucia A.. Clinica La Sagrada Familia. Instituto Medico ENERI; ArgentinaFil: Buezas, Mariano D.. Clinica La Sagrada Familia. Instituto Medico ENERI; ArgentinaFil: Diluca, Pablo. Clinica La Sagrada Familia. Instituto Medico ENERI; ArgentinaFil: Lylyk, Pedro. Clinica La Sagrada Familia. Instituto Medico ENERI; Argentin
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