1,664 research outputs found

    The split-operator technique for the study of spinorial wavepacket dynamics

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    The split-operator technique for wave packet propagation in quantum systems is expanded here to the case of propagating wave functions describing Schr\"odinger particles, namely, charge carriers in semiconductor nanostructures within the effective mass approximation, in the presence of Zeeman effect, as well as of Rashba and Dresselhaus spin-orbit interactions. We also demonstrate that simple modifications to the expanded technique allow us to calculate the time evolution of wave packets describing Dirac particles, which are relevant for the study of transport properties in graphene.Comment: 19 pages, 4 figure

    Lifestyles and surveillance of sexual and reproductive women’s health

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    Abstract: Background: The epidemic increase of diseases is closely related to lifestyle changes. The low adhesion to breast self-examination and cervical cytology hinders prevention and early diagnosis during the asymptomatic state of two silent diseases, with nonspecific symptoms that are a major cause of death by cancer in the Portuguese female population. Objectives: To analyze the influence of sociodemographic variables and lifestyles in the surveillance of sexual and reproductive health of Portuguese women. Methods: Quantitative, non-experimental, correlational and cross-sectional study, conducted with a non-probabilistic convenience sample of 522 women aged between 18 and 67 years old, who applied the questionnaires about Breast self-examination, Knowledge about cervical cancer and the Inventory "My Lifestyle" (Ribeiro, 1993. Results: The average age of women is 38.89 years old. Women aged 31-37 years old (28.6%), Portuguese (99.1%), cohabiting with a partner and / or child (74.0%), with an active employment status (67 5%), residing in urban areas (55.8%) with higher education and attending family planning consultations have better lifestyles, without statistical significance (F = 0.016, p = 0.899). Conclusions: Healthy behaviors and lifestyles are crucial to good overall health. Adhesion to surveillance of sexual and reproductive women’s health is influenced by several factors, including the place of residence, employment status and lifestyles. These variables must be considered by health professionals when planning periodic screenings.info:eu-repo/semantics/publishedVersio

    Rede Brasil Arroz: transferência de tecnologia para a orizicultura brasileira.

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    O foco principal do projeto é a equiparação da qualidade dos grãos e a competitividade da orizicultura das diversas regiões produtoras com a do Mercosul. Para alcançar esses objetivos, o projeto atua em todo território nacional, porém de maneira mais efetiva em Goiás, Mato Grosso, Mato Grosso do Sul, Alagoas, Tocantins, Maranhão, Rio Grande do Sul e Santa Catarina, onde estão sendo utilizados os princípios e métodos descritos

    Toxocara (Ascarididae) eggs in a Franciscan from Portugal (XVII-XVIII century): case report

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    Poster presented at the 43rd Annual North American Meeting of the Paleopatology Association. April 12-12, 2016, Atlanta, USAThe presence of adults of Toxocara in humans is rare, and it has been usually attributed to ingestion of adult worms and not the development of the larval stage in this host.This work represents the first report of Toxocara eggs associated with human burial.N/

    Quantization of graphene plasmons

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    In this article we perform the quantization of graphene plasmons using both a macroscopic approach, based on the classical expression for the average electromagnetic energy in a dielectric medium, and a quantum hydrodynamic model, in which graphene electrons are modeled as a charged fluid. Both models allow one to take into account the dispersion in the optical response, with the hydrodynamic model also allowing for the inclusion of the momentum dependence of the optical response (nonlocal effects). Using both methods, the electromagnetic field mode functions, and the respective frequencies, are determined for two different graphene structures. We show how to quantize graphene plasmons, considering that graphene is a dispersive medium, within the local and nonlocal descriptions. It is found that the dispersion of graphene's optical response leads to a nontrivial normalization condition for the mode functions. The obtained mode functions are then used to calculate the decay of an emitter, represented by a dipole, via the excitation of graphene surface plasmon polaritons. The obtained results are compared with the total spontaneous decay rate of the emitter and a near perfect match is found in the relevant spectral range. It is found that nonlocal effects in graphene's conductivity become relevant for the emission rate for small Fermi energies and small distances between the dipole and the graphene sheet.B.A.F. and N.M.R.P. acknowledge support from the European Commission through the project "Graphene-Driven Revolutions in ICT and Beyond" (Ref. No. 785219), and the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Financing UID/FIS/04650/2013. Additionally, N.M.R.P. acknowledges COMPETE2020, PORTUGAL2020, FEDER, and the Portuguese Foundation for Science and Technology (FCT) through Projects No. PTDC/FIS-NAN/3668/2013 and No. POCI-01-0145-FEDER-028114. B.A. acknowledges the hospitality of CeFEMA, where he was a visiting researcher during part of the time in which this work was developed, and financial support from Portuguese Foundation for Science and Technology (FCT) through Project No. CEECIND/02936/2017

    Antimicrobial activity of essential oils from Piper hispidum and Piper hispidinervum.

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    The objective of this work was to evaluate the antimicrobial activities of the plants Piper hispidum and P. hispidinervum

    The Off-Targets of Clustered Regularly Interspaced Short Palindromic Repeats Gene Editing

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    Funding: The work of VMB was funded by iNOVA4Health – UIDB/Multi/04462/2020 and UIDP/Multi/04462/2020, a program financially supported by Fundação para a Ciência e Tecnologia (FCT)/Ministério da Educação e Ciência through national funds, and the FCT grant PTDC/BEX-BCM/5900/2014.The repurposing of the CRISPR/Cas bacterial defense system against bacteriophages as simple and flexible molecular tools has revolutionized the field of gene editing. These tools are now widely used in basic research and clinical trials involving human somatic cells. However, a global moratorium on all clinical uses of human germline editing has been proposed because the technology still lacks the required efficacy and safety. Here we focus on the approaches developed since 2013 to decrease the frequency of unwanted mutations (the off-targets) during CRISPR-based gene editing.publishersversionpublishe
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