2,583 research outputs found

    Effective Targeting Of Proton Transfer At Ground And Excited States Of Ortho-(2 '-imidazolyl)naphthol Constitutional Isomers

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    Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Steady-state and time-resolved spectroscopy and quantum chemical computational studies were employed to investigate ground and excited state proton transfer of a novel series of ortho-(1H-imidazol-2-yl)naphthol constitutional isomers: 1-(1H-imidazol-2-yl)naphthalen-2-ol (1NI2OH), 2-(1H-imidazol-2-yl)naphthalen-1-ol (2NI1OH) and 3-(1H-imidazol-2-yl)naphthalen-2-ol (3NI2OH). Proper Near Attack Conformations (NACs) involving a strong intramolecular hydrogen bond between the naphthol moiety and the ortho-imidazole group account for the highest ground state acidity of 2NI1OH compared with 1NI2OH and 3NI2OH. Moreover, ESIPT for 2NI1OH and 3NI2OH is further associated with planar chelate H-ring formation whereas 1NI2OH shows the highest ESIPT barrier and a noncoplanar imidazole group. In addition to energetic and structural requirements, the final state also depends on electronic configuration of the ESIPT product with the neutral 3NI2OH showing an ICT effect that correlates with the excited state pKa of the cationic species.17424042415Brazilian Foundation INCT-CataliseConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Brazilian Foundation Pro-Reitoria de Pesquisa da UFMGConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Behavior of vascular resistance undergoing various pressure insufflation and perfusion on decellularized lungs

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    Bioengineering of functional lung tissue by using whole lung scaffolds has been proposed as a potential alternative for patients awaiting lung transplant. Previous studies have demonstrated that vascular resistance (Rv) could be altered to optimize the process of obtaining suitable lung scaffolds. Therefore, this work was aimed at determining how lung inflation (tracheal pressure) and perfusion (pulmonary arterial pressure) affect vascular resistance. This study was carried out using the lungs excised from 5 healthy male Sprague-Dawley rats. The trachea was cannulated and connected to a continuous positive airway pressure (CPAP) device to provide a tracheal pressure ranging from 0 to 15 cmH(2)O. The pulmonary artery was cannulated and connected to a controlled perfusion system with continuous pressure (gravimetric level) ranging from 5 to 30 cmH(2)O. Effective Rv was calculated by ratio of pulmonary artery pressure (P-PA) by pulmonary artery flow (V'(PA)). Rv in the decellularized lungs scaffolds decreased at increasing V'(PA), stabilizing at a pulmonary arterial pressure greater than 20 cmH(2)O. On the other hand, CPAP had no influence on vascular resistance in the lung scaffolds after being subjected to pulmonary artery pressure of 5 cmH(2)O. In conclusion, compared to positive airway pressure, arterial lung pressure markedly influences the mechanics of vascular resistance in decellularized lungs. (C) 2016 Elsevier Ltd. All rights reserved

    Sleep quality and chronic pain in community dwelling older adults: preliminary results

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    Background: The natural process of human aging causes biopsychosocial alterations, which can trigger chronic pain and poor sleep quality in older adults. Considering the high prevalence and possible association between these two clinical conditions, special attention from public health policies is necessary to provide quality aging. Objective: To verify if there is an association between chronic pain and sleep quality among older adults in the community. Methods: A quantitative, cross-sectional study on the association of chronic pain with the sleep quality among older people in the community. Participants were evaluated using the Pittsburgh Sleep Quality Index (PSQI); Visual Analog Pain scale; questionnaires of sociodemographic and clinical data, assessment of cognitive impairment through the Mini Mental State Examination, and anthropometric assessments. The data were submitted to descriptive statistics. The means between the groups of older people with and without chronic pain were compared using the Student's t test for independent samples and Pearson's correlation coefficient (r) was used to analyze the association of PSQI with pain intensity. Results: In total, 51 older women were included, with a mean age of 70 ± 8 years. The majority had a low level of education (52.9%), low financial income (64.7%), and chronic pain (56.9%). It was found that the older adults with chronic pain presented worse sleep quality when compared those without chronic pain and a moderate (r=0.595) and significant (p<0.01) correlation between sleep quality and the intensity of chronic pain was observed. Conclusion: Older adults in the community with chronic pain present worse sleep quality when compared to the older adults without pain. There is a strong correlation between the intensity of chronic pain and sleep quality in older adults; the greater the intensity of pain, the worse the sleep quality

    Web-GIS approach to preventive conservation of heritage buildings

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    The effective implementation of preventive conservation approaches demands the employment of standardized and robust tools able to integrate the data coming from multiple sources, inspection and diagnosis techniques, as well as to ensure the proper information transfer between expert and non-expert users. Aiming to make a step forward in the state of the art of current conservation approaches, a cutting edge Web-GIS technology resorting to the intuitiveness of 360° panoramas and 3D point clouds in combination with the Internet of Things is presented in this work, demonstrating how physical and digital worlds can be linked for proper documentation and management of cultural heritage. To validate such a pioneering approach, one of the most representative and complex heritage buildings of Spain is used as a case study: the General Historical Library of Salamanca.This work was financed by ERDF funds through the V Sudoe Interreg program within the framework of the HeritageCare project (Ref. SOE1/P5/P0258), by project Patrimonio 5.0 (SA075P17), by FEDER funds through the Competitive Factors Operational Program (COMPETE) and by the Foundation for Science and Technology (FCT) within the scope of projects POCI-01-0145-FEDER-007633. The authors would like to express their gratitude to the personnel from the General Historical Library of the University of Salamanca as well as to the Centre for Computer Graphics of the University of Minho for the web implementation of the platform

    Cyanobacteria reduction in the integrated culture of Pacific white shrimp and West India pointed venus in a biofloc system

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    This study aimed to evaluate the integrated culture of the Pacific white shrimp (Litopenaeus vannamei) and the West Indian pointed venus (Anomalocardia flexuosa) reared in a biofloc system. The performance of both species and the phytoplankton community were evaluated. Shrimp monoculture and three stocking densities of West Indian pointed venus (2.5, 5.0 and 7.5 Kg m-3) were evaluated in 0.05 m3 tanks. First of all, the addition of A. brasiliana did not affect the water quality parameters of the culture. Regarding the phytoplankton community, 13 taxa were found: 5 cyanobacteria, 4 dinoflagellates, 3 diatoms and 1 green algae. Although diatoms were dominant at the beginning of cultivation, in the middle and at the end a cyanobacterial dominance was observed (proven by ANOSIM and nMDS). The taxa that most contributed to the abundance of cyanobacteria were Aphanocapsa sp. and Pseudanabaena sp. Regarding the performance of the shrimp, all integrated treatments present the higher growth performances (final weight, yield and survival) when compared to shrimp monoculture. Moreover, gradual mortalities of A. brasiliana were observed, probably due to the high concentration of cyanobacteria. Thus, it can be observed that the integration of molluscs in shrimp culture can reduce the concentration of harmful algae and improve the zootechnical performance of the shrimp

    Corrosion resistance and antibacterial properties of copper coating deposited by cold gas spray

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    This work describes the morphology, corrosion resistance, and antibacterial performance of copper coating deposited onto carbon steel by cold gas spray (CGS). Cross-sectional images of the coating showed a dense microstructure, with porosity lower than 1%. XRD analysis revealed no oxides or phases different to pure copper. The results of electrochemical tests demonstrated the efficient barrier properties and the compact microstructure of the coating, which protected the substrate against corrosion in chloride solution for > 1000 h. The copper coating was effective as an antimicrobial agent for inhibiting the growth of Staphylococcus aureus, with bacterial growth being completely inhibited after 10 min of direct contact between the bacteria and the coating surface

    As atitudes dos alunos para com a Matemática: Um estudo em duas turmas do 6.º ano do Ensino Básico

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    O presente artigo irá incidir sobre um estudo realizado ao longo do ano letivo de 2017/2018, no âmbito da “Prática de Ensino Supervisionada II” do Mestrado em Ensino do 1.º Ciclo do Ensino Básico e de Matemática e Ciências Naturais no 2.º Ciclo do Ensino Básico. Este estudo teve como objetivo conhecer as atitudes dos alunos de uma turma do 6.º ano do ensino básico para com a Matemática antes e após o período de intervenção, de modo a compará-las e a compreender que aspetos da prática interventiva podem ter influenciado eventuais mudanças de atitude. Para tal, optou-se por uma metodologia quantitativa e, como método de recolha de dados, foram aplicados questionários, com itens fechados e abertos, antes e após o período de intervenção, assim como foram realizadas entrevistas aos alunos que mais diferenças mostraram entre estes dois períodos. Embora não se tenha verificado uma diferença significativa nas atitudes dos alunos para com a disciplina, em termos gerais o grupo evoluiu no que diz respeito a este domínio. Os resultados, para além de mostrarem que os alunos se sentem mais apoiados quando estão mais professoras presentes na sala de aula, também evidenciam que o tipo de atividades que foram desenvolvidas durante o período de intervenção – atividades exploratórias com recurso a materiais manipuláveis – constitui uma motivação extra para que os discentes se envolvam no trabalho matemático em sala de aula.Abstract This article will focus on a study carried out during 2017/2018 academic year, within the scope of the “Supervised Teaching Practice II” of the Master in Teaching in the 1st Cycle of Basic Education and Maths and Science in the 2nd Cycle of Basic Education. This study aimed to know the attitudes of students in a 6th grade class of basic education towards mathematics before and after the intervention period, in order to compare them and to understand which aspects of the interventional practice may have influenced possible changes in attitudes. To this end, a quantitative methodology was chosen and, as a method of data collection, questionnaires were applied, with closed and open items, before and after the intervention period, as well as interviews with students that most showed differences between these two periods. Although there was no significant difference in the students' attitudes towards the discipline, in general terms the group has evolved with respect to this domain. The results, in addition to showing that students feel more supported when there are more teachers present in the classroom, also show that the type of activities that were developed during the intervention period - exploratory activities using manipulable materials - constitutes extra motivation for students to get involved in mathematical work in the classroom.Résumé Cet article se concentrera sur une étude réalisée au cours de l'année académique 2017/2018, dans le cadre de la «Pratique pédagogique supervisée II» du Master en enseignement du 1er cycle de l'enseignement de base et des mathématiques et sciences naturelles du 2e Cycle d'éducation de base. Cette étude visait à connaître les attitudes des élèves d'une classe de base de 6e année à l'égard des mathématiques avant et après la période d'intervention, afin de les comparer et de comprendre quels aspects de la pratique interventionnelle ont pu influencer possibles changements d'attitude. À cette fin, une méthodologie quantitative a été choisie et, comme méthode de collecte des données, des questionnaires ont été appliqués, avec des éléments fermés et ouverts, avant et après la période d'intervention, ainsi que des entretiens avec des étudiants qui ont le plus montré des différences entre cettes deux périodes. Bien qu'il n'y ait pas de différence significative dans les attitudes des étudiants vis-à vis de la discipline, en général le groupe a évolué par rapport à ce domaine. Les résultats, en plus de montrer que les élèves se sentent plus soutenus lorsqu'ils sont plus d'enseignants présents dans la salle de classe, montrent également que le type d'activités développées au cours de la période d'intervention - activités exploratoires utilisant du matériel manipulable - constitue également motivation supplémentaire pour les élèves à s'impliquer dans des travaux mathématiques en classe.info:eu-repo/semantics/publishedVersio

    Synergistic warm inflation

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    We consider an alternative warm inflationary scenario in which nn scalar fields coupled to a dissipative matter fluid cooperate to produce power--law inflation. The scalar fields are driven by an exponential potential and the bulk dissipative pressure coefficient is linear in the expansion rate. We find that the entropy of the fluid attains its asymptotic value in a characteristic time proportional to the square of the number of fields. This scenario remains nearly isothermal along the inflationary stage. The perturbations in energy density and entropy are studied in the long--wavelength regime and seen to grow roughly as the square of the scale factor. They are shown to be compatible with COBE measurements of the fluctuations in temperature of the CMB.Comment: 13 pages, Revtex 3 To be published in Physical Review
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