432 research outputs found

    Effect of palladium on gold in core-shell catalyst for electrooxidation of ethanol in alkaline medium

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    In this paper the effect of small amounts of palladium deposited on gold nanoparticles supported on Vulcan XC-72 carbon (core-shell structure denoted Au@Pd/C) is studied. Different nominal atomic compositional ratios of Au@Pdx maintaining fixed gold nuclei and varying the amount of palladium (x = 0.10; 0.80 and 1.60) were synthesized via seed growth method for the ethanol oxidation reaction in alkaline medium. UV–Vis spectrometric, X-ray powder diffraction, X-ray energy dispersive spectroscopy, transmission electron microscopy and electrochemical measurements were performed for the characterization of these catalysts. Electrocatalytic activity toward ethanol oxidation on Au@Pd/C catalysts were investigated by cyclic voltammetry and chronoamperometry showed that [email protected]/C electrocatalyst has the highest current density and low onset potential for ethanol oxidation reaction in alkaline medium. In-situ Fourier transform infrared spectroscopy measurements demonstrated that acetate is the main product of ethanol oxidation and CO2 can be slightest observed, the latter could be visualized in greater quantity on catalyst [email protected]/C catalyst

    Modeling tourists' personality in recommender systems: how does personality influence preferences for tourist attractions?

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    Personalization is increasingly being perceived as an important factor for the effectiveness of Recommender Systems (RS). This is especially true in the tourism domain, where travelling comprises emotionally charged experiences, and therefore, the more about the tourist is known, better recommendations can be made. The inclusion of psychological aspects to generate recommendations, such as personality, is a growing trend in RS and they are being studied to provide more personalized approaches. However, although many studies on the psychology of tourism exist, studies on the prediction of tourist preferences based on their personality are limited. Therefore, we undertook a large-scale study in order to determine how the Big Five personality dimensions influence tourists' preferences for tourist attractions, gathering data from an online questionnaire, sent to Portuguese individuals from the academic sector and their respective relatives/friends (n=508). Using Exploratory and Confirmatory Factor Analysis, we extracted 11 main categories of tourist attractions and analyzed which personality dimensions were predictors (or not) of preferences for those tourist attractions. As a result, we propose the first model that relates the five personality dimensions with preferences for tourist attractions, which intends to offer a base for researchers of RS for tourism to automatically model tourist preferences based on their personality.GrouPlanner Project under the European Regional Development Fund POCI-01-0145-FEDER29178 and by National Funds through the FCT – Fundação para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology) within the Projects UIDB/00319/2020 and UIDB/00760/202

    Primeiro relato e colonização diferencial de espécies de Passiflora pelo biótipo B de Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) no Brasil

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    This note is the first report of Bemisia tabaci (Gennadius) biotype B colonizing passionvine in Brazil. We examined the colonization of nine Passiflora species by a wild B type population under greenhouse conditions. P. amethystina Mikan was the most preferred species for oviposition and colonization, whereas P. suberosa L., P. coriacea Juss. and two commercially cultivated species, P. alata Curtis and P. edulis Sims f. flavicarpa Degener, were mostly uncolonised. P. morifolia Mast., P. cincinnata Mast., P. foetida L. and P. caerulea L. showed intermediate levels of colonization. Such differential colonization might suggest some degree of resistance by certain Passiflora species or oviposition preference by B. tabaci.Esse trabalho descreve pela primeira vez a ocorrência do aleirodídeo Bemisia tabaci (Gennadius) biótipo B colonizando maracujazeiros no Brasil. Também foi examinada a colonização de nove espécies de Passiflora pelo inseto em condições de telado. P. amethystina Mikan foi a espécie de maior preferência para oviposição e colonização, enquanto P. suberosa L., P. coriacea Juss. e duas espécies cultivadas comercialmente, P. alata Curtis e P. edulis Sims f. flavicarpa Degener, foram pouco colonizadas pelo aleirodídeo. P. morifolia Mast., P. cincinnata Mast., P. foetida L. e P. caerulea L. exibiram níveis intermediários de colonização. Esses resultados sugerem que certas espécies de Passiflora exibem diferentes graus de resistência à colonização ou preferência para oviposição de B. tabaci biótipo B

    Illness perceptions of COVID-19 in Europe: Predictors, impacts and temporal evolution

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    Objective: Illness perceptions (IP) are important predictors of emotional and behavioral responses in many diseases. The current study aims to investigate the COVID-19-related IP throughout Europe. The specific goals are to understand the temporal development, identify predictors (within demographics and contact with COVID-19) and examine the impacts of IP on perceived stress and preventive behaviors. Methods: This was a time-series-cross-section study of 7, 032 participants from 16 European countries using multilevel modeling from April to June 2020. IP were measured with the Brief Illness Perception Questionnaire. Temporal patterns were observed considering the date of participation and the date recoded to account the epidemiological evolution of each country. The outcomes considered were perceived stress and COVID-19 preventive behaviors. Results: There were significant trends, over time, for several IP, suggesting a small decrease in negativity in the perception of COVID-19 in the community. Age, gender, and education level related to some, but not all, IP. Considering the self-regulation model, perceptions consistently predicted general stress and were less consistently related to preventive behaviors. Country showed no effect in the predictive model, suggesting that national differences may have little relevance for IP, in this context. Conclusion: The present study provides a comprehensive picture of COVID-19 IP in Europe in an early stage of the pandemic. The results shed light on the process of IP formation with implications for health-related outcomes and their evolution. © Copyright © 2021 Dias Neto, Nunes da Silva, Roberto, Lubenko, Constantinou, Nicolaou, Lamnisos, Papacostas, Höfer, Presti, Squatrito, Vasiliou, McHugh, Monestès, Baban, Alvarez-Galvez, Paez-Blarrina, Montesinos, Valdivia-Salas, Ori, Lappalainen, Kleszcz, Gloster, Karekla and Kassianos

    The Role of the Substantia Nigra Pars Compacta in Regulating Sleep Patterns in Rats

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    Background. As of late, dopaminergic neurotransmission has been recognized to be involved in the generation of sleep disturbances. Increasing evidence shows that sleep disturbances in Parkinson's disease (PD) patients are mostly related to the disease itself, rather than being a secondary phenomenon. Evidence contained in the literature lends support to the hypothesis that the dopaminergic nigrostriatal pathway is closely involved in the regulation of sleep patterns. Methodology/Principal Findings. To test this hypothesis we examined the electrophysiological activity along the sleep-wake cycle of rats submitted to a surgically induced lesion of the SNpc by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). We demonstrated that a 50% lesion of the substantia nigra pars compacta (SNpc) suffices to produce disruptions of several parameters in the sleep-wake pattern of rats. A robust and constant decrease in the latency to the onset of slow wave sleep (SWS) was detected throughout the five days of recording in both light [F((22.16)) = 72.46, p<0.0001] and dark [F((22.16)) = 75.0, p<0.0001] periods. Also found was a pronounced increase in the percentage of sleep efficiency during the first four days of recording [F((21.15)) = 21.48, p<0.0001], in comparison to the sham group. Additionally, the reduction in the SNpc dopaminergic neurons provoked an ablation in the percentage of rapid eye movement sleep (REM) during three days of the sleep-wake recording period with a strong correlation (r = 0.91; p<0.0001) between the number of dopaminergic neurons lost and the percentage decrease of REM sleep on the first day of recording. On day 4, the percentage of REM sleep during the light and dark periods was increased, [F((22.16)) = 2.46, p<0.0007], a phenomenon consistent with REM rebound. Conclusions/Significance. We propose that dopaminergic neurons present in the SNpc possess a fundamental function in the regulation of sleep processes, particularly in promoting REM sleep.AFIPCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, Dept Psicobiol, São Paulo, BrazilUniv Fed Parana, Dept Farmacol, BR-80060000 Curitiba, Parana, BrazilUniversidade Federal de São Paulo, Dept Psicobiol, São Paulo, BrazilFAPESP: 98/14.303-3Web of Scienc

    Angle-integrated measurements of the 26Al (d, n)27Si reaction cross section: a probe of spectroscopic factors and astrophysical resonance strengths

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    Measurements of angle-integrated cross sections to discrete states in 27Si have been performed studying the 26Al (d, n) reaction in inverse kinematics by tagging states by their characteristic γ \gamma -decays using the GRETINA array. Transfer reaction theory has been applied to derive spectroscopic factors for strong single-particle states below the proton threshold, and astrophysical resonances in the 26Al (p,γ \gamma) 27Si reaction. Comparisons are made between predictions of the shell model and known characteristics of the resonances. Overall very good agreement is obtained, indicating this method can be used to make estimates of resonance strengths for key reactions currently largely unconstrained by experiment

    Safety of nintedanib added to pirfenidone treatment for idiopathic pulmonary fibrosis

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    We assessed safety and tolerability of treatment with pirfenidone (1602-2403 mg day-1) and nintedanib (200-300 mg day-1) in patients with idiopathic pulmonary fibrosis (IPF). This 24-week, single-arm, open-label, phase IV study (ClinicalTrials.gov identifier NCT02598193) enrolled patients with IPF with forced vital capacity % pred ≫50% and diffusing capacity of the lung for carbon monoxide % pred ≫30%. Before initiating nintedanib, patients had received pirfenidone for ≫16 weeks and tolerated a stable dose of ≫1602 mg day-1 for ≫28 days. The primary end-point was the proportion of patients who completed 24 weeks of combination treatment on pirfenidone (1602- 2403 mg day-1) and nintedanib (200-300 mg day-1). Investigators recorded treatment-emergent adverse events (TEAEs), attributing them to pirfenidone, nintedanib, both or neither. 89 patients were enrolled; 73 completed 24 weeks of treatment (69 meeting the primary end-point) and 16 discontinued treatment prematurely (13 due to TEAEs). 74 patients had 418 treatment-related TEAEs, of which diarrhoea, nausea and vomiting were the most common. Two patients had serious treatmentrelated TEAEs. Combined pirfenidone and nintedanib use for 24 weeks was tolerated by the majority of patients with IPF and associated with a similar pattern of TEAEs expected for either treatment alone. These results encourage further study of combination treatment with pirfenidone and nintedanib in patients with IPF

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
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