Graphene setting the stage: tracking DNA hybridization with nanoscale resolution

In this study we use nanophotonic effects of graphene to study DNA hybridization: the z−4 nanoscale distance-dependence of the fluorescence lifetime for fluorophores located in the vicinity of graphene is for the first time used to track a DNA hybridization reaction with nanoscale resolution in real time. First, a nanostaircase with ≈2 nm steps from 0 to a total height of 48 nm is used as a nanoruler to confirm the distance dependence law. We find that the axial sensitivity is suited to determine the nanoscale surface roughness of these samples. The proof-of-concept DNA experiments in aqueous medium involve the hybridization of fluorescently labelled DNA beacons attached to CVD grown graphene with complementary (target) DNA added in solution. We track the conformational changes of the beacons statistically by determining the fluorescence lifetimes of the labelling dye and converting them into nanoscale distances from the graphene. In this way, we are able to monitor the vertical displacement of the label during DNA-beacon unfolding with an axial resolution reaching down to 1 nm. The measured distance increase during the DNA hybridization reaction of about 10 nm matches the length of the target DNA strand. Furthermore, the width of the fluorescence lifetime distributions could be used to estimate the molecular tilt angle of the hybridized ds-DNA configuration. The achieved nanoscale sensitivity opens innovation opportunities in material engineering, genetics, biochemistry and medicine.INL received support for this project from the CCDR-N via the project 'Nanotechnology based functional solutions' (Grant No. NORTE-01-0145-FEDER-000019) and from the Portuguese Foundation for Science and Technology (FCT) via the project 'ON4SupremeSens' PTDC/NAN-OPT/29417/2017. Edite Figueiras received a Marie Curie fellowship via the EU-EC COFUND program 'NanoTRAINforGrowth' (Grant No. 600375). U Minho research was partially supported by the FCT in the framework of the Strategic Funding UID/FIS/04650/2013

Spectral-temporal luminescence properties of Colloidal CdSe/ZnS Quantum Dots in relevant polymer matrices for integration in low turn-on voltage AC-driven LEDs

This work employs spectral and spectral-temporal Photoluminescence (PL) spectroscopy techniques to study the radiative mechanisms in colloidal CdSe/ZnS Quantum Dot (QD) thin films without and with 1% PMMA polymer matrix embedding (QDPMMA). The observed bimodal transient-spectral PL distributions reveal bandgap transitions and radiative recombinations after interdot electron transfer. The PMMA polymer embedding protects the QDs during the plasma-sputtering of inorganic layers electroluminescent (EL) devices, with minimal impact on the charge transfer properties. Further, a novel TiO2-based, all-electron bandgap, AC-driven QLED architecture is fabricated, yielding a surprisingly low turn-on voltage, with PL-identical and narrow-band EL emission. The symmetric TiO2 bilayer architecture is a promising test platform for alternative optical active materials.European Commission, Seventh Framework Programme (600375); European Commission, Horizon 2020 Framework Programme (828841); European Regional Development Fund, INTERREG V-A España-Portugal (POCTEP) 2014-2020 (0181_NANOEATERS_1_EP); CCDR-N (NORTE-01-0145-FEDER-000019); Fundação para a Ciência e a Tecnologia (UIDB/04650/2020)

Estudo de Caso do Uso de Linguagens de Script em Jogos

Este artigo introduz o conceito de linguagens de script,apresentando características das linguagens mais usadas. Também apresenta um exemplo de uma aplicação que integra a linguagem de script Ruby e C++, usando um interpretador Ruby embarcado para uso em jogo

Performance evaluation of IB-DFE-based strategies for SC-FDMA systems

The aim of this paper is to propose and evaluate multi-user iterative block decision feedback equalization (IB-DFE) schemes for the uplink of single-carrier frequency-division multiple access (SC-FDMA)-based systems. It is assumed that a set of single antenna users share the same physical channel to transmit its own information to the base station, which is equipped with an antenna array. Two space-frequency multi-user IB-DFE-based processing are considered: iterative successive interference cancellation and parallel interference cancellation. In the first approach, the equalizer vectors are computed by minimizing the mean square error (MSE) of each individual user, at each subcarrier. In the second one, the equalizer matrices are obtained by minimizing the overall MSE of all users at each subcarrier. For both cases, we propose a simple yet accurate analytical approach for obtaining the performance of the discussed receivers. The proposed schemes allow an efficient user separation, with a performance close to the one given by the matched filter bound for severely time-dispersive channels, with only a few iterations

Poultry shelf-life enhancing potential of nanofibers and nanoparticles containing Porphyra dioica extracts

Aqueous extracts of commercially available red macroalgae Porphyra dioica were integrated as inner coatings of food-grade polypropylene (PP) films through use of electrospinning and electrospraying technologies. Two coating formulations (A = 5 wt% P. dioica extract and 7.5 wt% polyvinyl alcohol (PVA); B = 1 wt% P. dioica extract, 1 wt% PVA, and 17% gelatine) were evaluated as to their capacity to delay spoilage of minced chicken breasts, through monitoring of microbial growth (total mesophile aerobic colony counts), colour stability, lipid oxidation (thiobarbituric acid reactive substances (TBARS)), and sensory analysis over a 4-day refrigerated storage. Scanning electron microscopy (SEM) imaging revealed an increased nanofiber and nanoparticle density on extract-enriched fibers, without compromise to their morphology or the homogeneity of the coatings. Total microbial counts on coating B samples was significantly (p < 0.001) reduced compared to uncoated plastic wraps. The coated samples also exhibited fewer colour degradation, though the coatings did not di er substantially from uncoated plastic wrap. Sensory analysis test subjects successfully distinguished the raw samples based on their treatment and gave a positive approval rating (66.7%) to the extract-enriched coatings when asked about edibility post storage.info:eu-repo/semantics/publishedVersio

A infância representada no livro escolar: tipos de textos e estereótipos sociais

Esta investigação inscreve-se dominantemente no âmbito dos estudos da criança e ancora a sua área específica nas questões linguísticas, assumindo os pressupostos teóricos e metodológicos da análise do discurso (de tradição francófona), considerando também contributos de áreas conexas. Analisa textos de manuais/livros escolares usados no sistema de ensino português, pretendendo tornar visíveis as imagens que estes constroem das crianças e da infância, bem como os recursos linguísticos mais relevantes associados a tal construção. Procura desvendar a representatividade das tipologias textuais nos manuais e de que forma estas contribuem para a construção das referidas imagens. Conclui que as crianças dos textos são seres sem voz e sem poder, consumidoras, mas não coprodutoras de cultura, com os textos inculcando valores conformadores da manutenção da ordem social estabelecida, sendo a forma como as tipologias textuais estão organizadas contribuidora para se alcançar esse propósito.This research forms primarily part of the child studies and is based on its specific field of linguistic issues, assuming the theoretical and methodological assumptions of the speech analysis (of French-speaking tradition), having also regard the inputs of related fields. It analyses texts from handbooks/textbooks used on the Portuguese educational system, intending to reveal pictures that these books construct about children and childhood, as well as the most relevant linguistic resources associated with such construction. This paper aims at unravelling the representation of the text typologies in the handbooks and how these can contribute for building of such pictures. From this, one can conclude that children from the texts are voiceless and have no power, they are consumers but not co-producers of culture, with these texts instilling conservative values for maintaining the established social order, but also that the way texts typologies are organized to contribute for reaching that propose.Esta investigación se ensere en el ámbito de los estudios del niño y más precisamente en la área de las cuestiones lingüísticas, asumiendo los presupuestos teóricos e metodológicos de la análisis del discurso (de tradición francófona), considerando también aportes de las áreas conexas. Analiza textos de manuales/libros escolares usados en el sistema de enseñanza portugués, pretendiendo tornar visibles las imágenes que este construyen de los niños y de la infancia, bien como los recursos lingüísticos más relevantes asociados a esa construcción. Busca desvendar la representatividad de las tipologías textuales en los manuales y de qué forma contribuyen para la construcción de las referidas imágenes. Concluye que los niños de los textos son seres sin voz y sin poder, consumidores, pero no coproductores de cultura y que los textos inculcan valores conformadores de manutención del orden social establecido, mas también que la forma como las tipologías textuales están organizadas contribuye para alcanzar ese propósito.CIEC - Centro de Investigação em Estudos da Criança, IE, UMinho (UI 317 da FCT), Portugal. Fundos Nacionais através da FCT (Fundação para a Ciência e a Tecnologia) e cofinanciado pelo Fundo Europeu de Desenvolvimento Regional (FEDER) através do COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) no âmbito do CIEC (Centro de Investigação em Estudos da Criança, da Universidade do Minho) com a referência POCI-01-0145-FEDER-007562info:eu-repo/semantics/publishedVersio

Subwavelength neuromorphic nanophotonic integrated circuits for spike-based computing : challenges and prospects

Event-activated biological-inspired subwavelength (sub-λ) optical neural networks are of paramount importance for energy-efficient and high-bandwidth artificial intelligence (AI) systems. Despite the significant advances to build active optical artificial neurons using for example phase-change materials, lasers, photodetectors, and modulators, miniaturized integrated sources and detectors suited for few-photon spike-based operation and of interest for neuromorphic optical computing are still lacking. In this invited paper we outline the main challenges, opportunities, and recent results towards the development of interconnected neuromorphic nanoscale light-emitting diodes (nanoLEDs) as key-enabling artificial spiking neuron circuits in photonic neural networks. This method of spike generation in neuromorphic nanoLEDs paves the way for sub-λ incoherent neural circuits for fast and efficient asynchronous brain-inspired computation

Power allocation strategies for distributed precoded multicell based systems

Multicell cooperation is a promising solution for cellular wireless systems to mitigate intercell interference, improve system fairness, and increase capacity. In this article, we propose power allocation techniques for the downlink of distributed, precoded, multicell cellular-based systems. The precoder is designed in two phases: first the intercell interference is removed by applying a set of distributed precoding vectors; then the system is further optimized through power allocation. Three centralized power allocation algorithms with per-BS power constraint and diferente complexity trade-offs are proposed: one optimal in terms of minimization of the instantaneous average bit error rate (BER), and two suboptimal. In this latter approach, the powers are computed in two phases. First, the powers are derived under total power constraint (TPC) and two criterions are considered, namely, minimization of the instantaneous average BER and minimization of the sum of inverse of signal-to-noise ratio. Then, the final powers are computed to satisfy the individual per-BS power constraint. The performance of the proposed schemes is evaluated, considering typical pedestrian scenarios based on LTE specifications. The numerical results show that the proposed suboptimal schemes achieve a performance very close to the optimal but with lower computational complexity. Moreover, the performance of the proposed per-BS precoding schemes is close to the one obtained considering TPC over a supercell.Portuguese CADWIN - PTDC/ EEA TEL/099241/200

Infecções em pacientes pediátricos submetidos a transplante hepático

OBJECTIVE: To identify bacterial, viral, and fungal infections in the first 20 pediatric patients submitted to liver transplant at Hospital de Clínicas de Porto Alegre.PATIENTS AND METHODS: Twenty-one liver transplants were performed in 20&nbsp; infant and adolescent patients from March 1995 to September 1997, at Hospital deClínicas de Porto Alegre. All transplanted organs were taken from deceased donors with the same ABO blood type as the organ transplant recipient. Nine patientsreceived a whole liver transplant, and 11 patients received a reduced liver transplant. Bacterial infection was diagnosed by the existence of clinical and laboratory evidence;and/or by hemoculture; and/or by positive&nbsp; cultures. For the diagnosis of viral infections, patients were examined for Epstein Barr virus and for cytomegalovirus. For the diagnosis of fungal infection, hemocultures and secretion cultures were taken, and patients were also submitted to draining and sample collections, such as urine samples using a catheter.RESULTS: Of the 20 organ transplant recipient patients, two died within the first 24- 48 hours, and only four of the patients did not present any infections and/or positive cultures that were clinically significant. Fourteen patients had bacterial infection, and nine patients had more than one case of infection. The most frequently found organisms were Staphylococus aureus and epidermidis, and Xanthomonas maltophilia. Five transplant recipients were positive for cytomegalovirus antigenemia, and only one of these recipients was seronegative before the transplant. Fungal infection was diagnosed in two patients, and a third patient presented a positive culture of the biliary drain.CONCLUSIONS: Of the 20 liver transplant recipients, four died due to infection complications. By exerting a careful control, and establishing appropriate prophylacticand therapeutic measures, infection and its consequences may be reduced.OBJETIVO: Identificar infecções bacterianas, virais e fúngicas nos primeiros 20pacientes pediátricos submetidos a transplante de fígado no HCPA.PACIENTES E MÉTODOS: 21 transplantes foram realizados em 20 crianças eadolescentes, no período de março de 1995 a setembro de 1997, no HCPA. Todosos transplantes foram de doador cadavérico, do mesmo grupo sangüíneo ABO.Nove transplantes foram de fígado inteiro e 11, de fígado reduzido. O diagnósticode infecção bacteriana foi feito quando havia evidências clínico-laboratoriais e/ouhemocultura e/ou outros culturais positivos. Os vírus pesquisados foram citomegaloe Epstein Barr. Fungos eram pesquisados através de hemoculturas e culturas desecreções, drenos e coleções, cateteres e urina.RESULTADOS: Dos 20 pacientes transplantados, dois morreram nas primeiras24-48 horas e apenas quatro não apresentaram infecção e/ou culturais positivos,clinicamente significativos. Quatorze pacientes apresentaram infecção bacteriana,sendo que nove pacientes apresentaram mais do que um episódio infeccioso. Osorganismos mais freqüentes foram Staphylococus aureus e epidermidis eXantomonas maltophilia. Cinco receptores positivaram antigenemia para CMV, sendoque apenas um apresentava sorologia negativa no pré-transplante. Infecção fúngicafoi diagnosticada em dois pacientes e um terceiro paciente apresentou cultura dodreno biliar positiva.CONCLUSÕES: Dos 20 pacientes transplantados, quatro foram ao óbito porcomplicações infecciosas. Um controle cuidadoso e medidas profiláticas eterapêuticas adequadas podem diminuir infecções e suas conseqüências apóstransplante hepático