1,028 research outputs found

    First-principles GW calculations for DNA and RNA nucleobases

    Full text link
    On the basis of first-principles GW calculations, we study the quasiparticle properties of the guanine, adenine, cytosine, thymine, and uracil DNA and RNA nucleobases. Beyond standard G0W0 calculations, starting from Kohn-Sham eigenstates obtained with (semi)local functionals, a simple self-consistency on the eigenvalues allows to obtain vertical ionization energies and electron affinities within an average 0.11 eV and 0.18 eV error respectively as compared to state-of-the-art coupled-cluster and multi-configurational perturbative quantum chemistry approaches. Further, GW calculations predict the correct \pi -character of the highest occupied state, thanks to several level crossings between density functional and GW calculations. Our study is based on a recent gaussian-basis implementation of GW with explicit treatment of dynamical screening through contour deformation techniques.Comment: 5 pages, 3 figure

    Irreducible modules over finite simple Lie conformal superalgebras of type K

    Get PDF
    We construct all finite irreducible modules over Lie conformal superalgebras of type KComment: Accepted for publication in J. Math. Phys

    Social Relations and Methods in Recommender Systems: A Systematic Review

    Get PDF
    With the constant growth of information, data sparsity problems, and cold start have become a complex problem in obtaining accurate recommendations. Currently, authors consider the user's historical behavior and find contextual information about the user, such as social relationships, time information, and location. In this work, a systematic review of the literature on recommender systems that use the information on social relationships between users was carried out. As the main findings, social relations were classified into three groups: trust, friend activities, and user interactions. Likewise, the collaborative filtering approach was the most used, and with the best results, considering the methods based on memory and model. The most used metrics that we found, and the recommendation methods studied in mobile applications are presented. The information provided by this study can be valuable to increase the precision of the recommendations

    Do difficulties in emotion regulation impact self-esteem and adult attachment? – the role of trauma

    Get PDF
    Abstract in proceedings of the Fourth International Congress of CiiEM: Health, Well-Being and Ageing in the 21st Century, held at Egas Moniz’ University Campus in Monte de Caparica, Almada, from 3–5 June 2019.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.info:eu-repo/semantics/publishedVersio

    Varenicline suicidal ideation in psychiatric patients − a case report and systematic review

    Get PDF
    Varenicline, a partial agonist selective for a4b2 nicotinic acetylcholine receptor subtypes, was approved in 2006 by the FDA as an aid for smoking cessation in association to counselling. Since its commercialization, many individual cases reported psychiatric adverse effects on patients prescribed with varenicline− such as depressive mood, anxiety, suicidal ideation or even suicidal attempt. Subsequently, the FDA required the addition of a Boxed Warning to this drug. It is believed this reports leaded to some apprehension on its prescription [1].info:eu-repo/semantics/publishedVersio

    Plant Biomarker Pattern, Apples grown with various availability of organic nitrogen and with or witout the use of pesticides

    Get PDF
    In the recent years there has been an increasing focus on the quality and health value of organic plant products compared with conventional products. The use of pesticides and concentrated fertilisers in conventional agriculture implies a risk of effects on plant composition, which may affect health of the consumer (Brandt & Mølgaard, 2001). To determine if organically grown plant food could provide more or less benefits to health than conventional food, a first step is to investigate the differences in the composition and relative concentration of natural compounds in the plant products. In this project apples were grown with two levels of nitrogen availability and with or without the use of pesticides. The apples were screened for changes in the phytochemical composition and concentration. The work is affiliated to the project "Organic food and health" supported by the Danish Research Centre for Organic Farming (DARCOF). Biomarkers and biomarker patterns were presented in plants cultivated with low and high N and with pesticides. One biomarker was related to: • the type of N with and without pesticides • pesticides at high N and type of N without pesticides • pesticides at low and high N One biomarker pattern was related to: • the type of N • the type of N without pesticides • pesticides at low N and type of N without pesticides • pesticides at high N and type of N with pesticide

    Longevidade da solução de Verhöeff

    Get PDF
    As fibras elásticas representam cerca de 5% do tecido conjuntivo. São constituídas por elastina e microfibrilhas sendo responsáveis pelas propriedades de flexibilidade e retracção elástica dos tecidos. A Técnica de Verhoeff é o método mais comum para demonstrar a presença de fibras elásticas, proporcionando bons resultados. Esta técnica baseia-se num método regressivo, sendo preparada apenas aquando da sua utilização. No entanto, Bancroft e Gamble indicam que resultados satisfatórios têm sido obtidos com a utilização da solução até 48 horas. Estabeleceu-se como objectivo geral comparar a solução de Verhoeff extemporânea e a solução de Verhoeff não extemporânea, verificando a posteriori se ambas permitem obter resultados satisfatórios similares. Definindo-se especificamente: determinar a influência do tempo de repouso da solução de Verhoeff não extemporânea na coloração das fibras elásticas de cortes histológicos de pele, pulmão e artéria de origem suína; analisar e comparar microscopicamente as diferenças entre a solução extemporânea de Verhoeff (lâminas controlo) e o conjunto de diferentes tempos de repouso dessa mesma solução; aferir a longevidade da solução de Verhoeff, indicar o tempo de repouso de solução de Verhoeff até ao qual esta é passível de utilização

    Recycling of Cr/Ni/Cu plating wastes as black ceramic pigments

    Get PDF
    The non-ferrous metal industry, such as Cr/Ni/Cu plating, produces acid sludge which is usually neutralized with lime slurry in batch processes, and the resulting waste is dewatered by vacuum filtration or filter-pressing. Dewatered sludge contains calcium sulphate (CaSO4) coming from the neutralization process, as well as transition metals (Cr, Ni and Cu), oil, grease and suspended solids. In this communication, two residual sludges from Cr/Ni/Cu plating have been dried (110 C) and fired (1100 C), and both dried (gray coloured) and fired powders (black coloured) have been characterized by DTA-TG, XRD and SEMEDX techniques. XRD shows only quartz crystallization in dried samples, while NiCr2O4 chromite spinel and NiO periclase crystallize in fired powders, along with CaSO4 anhydrite and CaSiO3 wollastonite. The powders have been introduced as ceramic pigments into three different conventional glazes: a) a lead bisilicate (PbO.2SiO2) double fire frit (1000 C), b) a double fire frit with low lead content (1000 C), and c) a double fire frit without lead (1050 C). Glazed samples were characterized by UV-Vis-NIR (diffuse reflectance) and CIEL⁄a⁄b⁄ (color parameters). Dried powders induce glaze defects (pin-holing and crawling), but fired powders did not show these faults exhibiting more intense (higher L⁄ ) and yellowish (higher b⁄ ) black colors than the standard spinel

    Comparison of inverse planning systems based on biological or physical factors: Pinnacle®, Corvus® and Monaco®

    Get PDF
    Radiotherapy (RT) is one of the most important approaches in the treatment of cancer and its performance can be improved in three different ways: through the optimization of the dose distribution, by the use of different irradiation techniques or through the study of radiobiological initiatives. The first is purely physical because is related to the physical dose distributiuon. The others are purely radiobiological because they increase the differential effect between the tumour and the health tissues. The Treatment Planning Systems (TPS) are used in RT to create dose distributions with the purpose to maximize the tumoral control and minimize the complications in the healthy tissues. The inverse planning uses dose optimization techniques that satisfy the criteria specified by the user, regarding the target and the organs at risk (OAR’s). The dose optimization is possible through the analysis of dose-volume histograms (DVH) and with the use of computed tomography, magnetic resonance and other digital image techniques

    La lucha por el reconocimiento y las prácticas de autolesión en la constitución identitaria en la experiencia estudiantil

    Get PDF
    The present work aims to interpret the relationships between the feeling of recognition that students build and the production of violence against their own body. The arguments presented refer to the results of a socio-educational research in which the meanings that students construct about emotions and bodies and their relationship with the production of violence in two secondary schools in the Province of Buenos Aires, Argentina. Based on the testimonies produced by the socio-educational study where 40 students from two state public schools in peripheral urban areas of the city of La Plata, Province of Buenos Aires, Argentina were interviewed, it is possible to affirm that the need for self-assertion constitutes an axis central in the processes of juvenile subjectivation.  In line with the qualitative approach adopted, in-depth interviews and focus groups were selected as data collection instruments, since they constitute relevant tools when seeking to understand the subjective experience of the participants. From the accounts of experiences of cuts to the skin, it is possible to argue that self-destruction practices are closely linked to struggles for recognition. Faced with the gaze and the perceived judgments, young people develop different strategies to face social pain in order to restore social self-worth.El presente trabajo se propone interpretar las relaciones entre el sentimiento de reconocimiento que construyen las y los estudiantes y la producción de las violencias contra el propio cuerpo. Los argumentos expuestos se refieren a los resultados de una investigación socioeducativa en la que se indagó respecto a los sentidos que construyen las y los estudiantes sobre las emociones y los cuerpos y su relación con la producción de las violencias en dos escuelas secundarias de la Provincia de Buenos Aires, Argentina. A partir de los testimonios que arroja el estudio socioeducativo donde se entrevistó a 40 estudiantes de dos escuelas públicas estatales de zonas urbano periféricas de la ciudad de La Plata, Provincia de Buenos Aires, Argentina, es posible afirmar que la necesidad de autoafirmación constituye un eje central en los procesos de subjetivación juvenil.  En consonancia con el abordaje cualitativo adoptado, se seleccionaron como instrumentos de recolección de datos las entrevistas en profundidad, ya que constituyen herramientas pertinentes cuando se busca comprender la experiencia subjetiva de los participantes. A partir de los relatos de experiencias de cortes en la piel es posible sostener que las prácticas de autodestrucción guardan un vínculo estrecho con las luchas por el reconocimiento. Ante la mirada y los juicios percibidos, las y los jóvenes desarrollan diferentes estrategias para afrontar el dolor social a los fines de restituir la auto valía social
    corecore