Células solares orgânicas baseadas em MEH-PPV

Mestrado em Engenharia FísicaNo presente trabalho procedeu-se ao estudo e fabrico de células solares orgânicas do tipo bulk heterojunction, baseadas no polímero poly(2-methoxy-5- (2-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV) dopada com a nanoestrutura [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) em filmes finos . A caracterização opto-electrónica revelou uma forte absorção na zona espectral azul-verde, confirmando a aplicabilidade destes materiais para este tipo de dispositivos. Foram obtidos valores relevantes em parâmetros como factor de forma e eficiência. É apresentada uma tentativa de explicação dos resultados com base nas propriedades micro-eléctricas e morfológicas. Produziram-se, de igual forma, células flexíveis baseadas na mesma estrutura, tendo em vista a sua aplicabilidade em larga escala. ABSTRACT: In this work some thin film bulk-heterojunction organic solar cells based on polymer poly(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene) (MEHPPV) doped with nanostructures [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) was made and studied. The opto-electrical characterization showed a strong absorption in the blue-green spectrum region, confirming the applicability of these materials for this kind of devices. Relevant data was obtained for fill-factors and efficiency. An attempt to explain the macroscopic behavior based on micro-electrical and morphological properties was done. Flexible devices based on same structure were also made in order to test the possible application in large scale

Estudo das respostas neurofisiológicas cerebrais em sujeitos saudáveis associadas à aplicação de estimulação magnética transcraniana repetitiva no córtex direito

A estimulação magnética transcraniana (EMT) é uma técnica de estimulação do córtex cerebral que permite modular a excitabilidade cortical, subsistindo controvérsia sobre o seu efeito na oximetria cerebral. Neste estudo quisemos avaliar a variação dos valores de oximetria (de forma direta) e do fluxo cerebral regional (de forma indireta), após uma única sessão de estimulação magnética de tipo excitatório, inibitório ou placebo sobre o hemisfério direito, em indivíduos jovens e saudáveis. Os testes realizaram-se em 31 voluntários, que foram aleatoriamente divididos em 3 grupos sendo cada um dos grupos submetidos a um tipo de estimulação. Foi realizada a medição da oximetria cerebral regional (OCR) antes e após a estimulação. Um grupo de controlo foi criado com 49 voluntários que não foram sujeitos ao protocolo, servindo apenas para registar os valores de OCR antes e após um intervalo de 30min. Os resultados revelaram uma diminuição significativa nos valores da oximetria do hemisfério direito no grupo que sofreu uma estimulação excitatória, situação que se verificou também no grupo placebo. No grupo que sofreu estimulação inibitória não se verificaram alterações estatisticamente significativas. Foram encontrados achados adicionais: os valores médios de oximetria mostram-se superiores, com significância estatística, no sexo masculino em comparação com o feminino, tanto nos valores antes como nos depois da estimulação e verificou-se também que o hemisfério direito apresenta valores de oximetria superiores aos do hemisferio esquerdo no grupo de controlo masculino.In this study we aimed to evaluate the variation of the regional cerebral oximetry (RCO), on the prefrontal cortex, after one session of Transcranial magnetic stimulation (TMS) – excitatory Theta Burst (TBS), inhibitory TBS and sham stimulation in healthy young individuals. The tests were realized in 32 volunteers, randomly distributed by three groups, being each group submitted to one of the previously described TBS (two way blinded). The RCO was obtained before and after the TMS. A fourth group was created in order to study the normal variation of RCO, in a 30 min interval, without passing through the TBS protocol. In this study we found a significant decrease, in males, on the right prefrontal OCR of the excitatory TBS group which also was noticed on the sham group. On the inhibitory TBS group no significant changes in OCR were obtained for either males or females. Parallel findings were noticed on the fourth group: prefrontal OCR mean values were significantly superior on males than females. Also right prefrontal OCR values were superior than left ones on males, but no significant change was observed between both hemispheres in females

Varietal thiols in white wines from portuguese grape varieties

Wines from Antão Vaz, Arinto, Fernão Pires, Verdelho da Madeira and Viosinho grape cultivars, from 2009 and 2010 vintages, were studied in order to characterize the volatile thiols profile, namely 4-mercapto-4-methyl-pentan-2-one (4MMP), 3-mercaptohexan-1-ol (3MH) and 3-mercaptohexyl acetate (3MHA). Volatile thiols profile of these wines was also compared to a Sauvignon blanc wine produced in Portugal. Besides sensory analysis, all wines were analyzed using GC coupled to different detectors, namely FID, FPD, MS and Olfactometry (GC-O). In all wines, GC-O analyses showed the existence of two olfactory zones related to the presence of 4MMP and 3MH. A third olfactory zone for 3MHA was only observed for the youngest wines. The wines produced from Portuguese cultivars presented aromatic intensities comparable or even higher than those obtained in the Sauvignon blanc wine. Indeed, 3MH was found in all wines and the highest amounts were observed in Antão Vaz, Arinto and Viosinho wines. In general, these findings are in agreement with those obtained by sensory analysis

Borboletas frugívoras de fragmentos de Mata Atlântica no noroeste do Rio Grande do Sul, Brasil (Lepidoptera: Nymphalidae)

Resumo: O presente estudo teve como objetivo principal fornecer uma lista e avaliar a diversidade das espécies de borboletas frugívoras em dois fragmentos de Floresta Estacional Decidual no noroeste do Rio Grande do Sul. As amostragens foram mensais entre junho de 2014 a março de 2015. Para a captura das borboletas foram utilizadas armadilhas com isca atrativa à base de banana fermentada em caldo de cana. Após um esforço amostral de 4800 horas, foram amostrados 760 indivíduos distribuídos em 49 espécies de borboletas. Satyrinae foi a subfamília com maior riqueza e abundância de espécies. Hypothyris euclea laphria (Doubleday) representou um novo registro para o estado. A abundância de borboletas apresentou-se de forma heterogênea em ambos os fragmentos no decorrer dos meses amostrados. Apesar de ser um inventariamento de curto prazo, a riqueza de borboletas foi bastante representativa no noroeste do Rio Grande do Sul. Recomenda-se intensificar estudos semelhantes, para prover informações no intuito de conservação dos hábitats. Butterflies from Atlantic Forest fragments in northwest of Rio Grande do Sul, Brasil (Lepidoptera: Nymphalidae) Abstract. This study aimed to provide a list and evaluate the diversity of species of fruit-feeding butterflies in two fragments of Decidual Seasonal Forest in the northwest of Rio Grande do Sul. Samples were collected monthly, between June 2014 and March 2015. Traps with attractive baits of fermented banana in sugar cane juice were used to capture the butterflies. After a 4800 hours sampling effort, 760 butterflies were sampled and distributed into 49 species. Satyrinae was the family with the greatest wealth and abundance of species. Hypothyris euclea laphria (Doubleday) represented a new registry for the state. The abundance of butterflies was heterogeneous in both fragments during the months sampled. Despite being a short-term inventory, butterfly richness was quite representative in the northwest of Rio Grande do Sul. It is recommended to intensify similar studies to provide information for the conservation of habitats

Evaluating Nanofiltration Effect on Wine 87Sr/86Sr Isotopic Ratio and the Robustness of this Geographical Fingerprint

When aiming to use the strontium isotopic ratio 87Sr/86Sr for the traceability and authentication of wine, it is crucial to understand the impacts of anthropogenic factors and technological processes on this parameter.  A study was developed to evaluate the effect of nanofiltration (NF), a membrane process with several applications in oenology, on the isotopic ratio 87Sr/86Sr of wine, testing its robustness as geographical tracer.  NF assays, for dealcoholisation, were carried out at laboratory scale with model solutions and white and red wines from Portuguese DO. High rejections to strontium (97%) and tartaric acid (> 70%) and low rejection to ethanol (< 10%) at 15 bar were observed in model solutions. Wines and NF-processed wines (17 bar; 2.1 L/min) were evaluated for physicochemical composition (including phenolic composition, chromatic characteristics and polysaccharides), multi-elemental composition and 87Sr/86Sr ratio by Q-ICPMS.  The preferential membrane permeation of ethanol was associated with a slight increase in the quality parameters of the wine (anthocyanins and polysaccharides). High rejections to mineral elements, including heavy metals, were observed. Rejection to Sr was mostly higher than 95%. No significant differences in the 87Sr/86Sr of wines and corresponding permeate fractions were observed, suggesting that NF does not preclude the use of this parameter for wine traceability purposes.

Degradabilidade ruminal das silagens e produtividade de cultivares de sorgo de tipo forrageiro e granífero

Forages for feeding dairy cows should conciliate the potential for high dry matter yield per unit area, maximizing animal stocking rate, with high nutritive value, which enables decreasing the amount of concentrate feedstuffs per milk unit produced. Eighteen sorghum cultivars were cultivated 0.70 m apart and with 12 plants per linear meter. Plants harvested at the milk-to-dough stage were ensiled in the laboratory. Eleven agronomic and chemical traits were evaluated. Silage samples were incubated in situ and the effective ruminal dry matter degradation (DEF) was calculated assuming a fractional passage rate of -0.04 h-1. Dry matter yield was 13.0 ± 2.3 (mean ± S.D.) t ha-1. The neutral detergent fiber content was 50.3 ± 3.8 and the DEF was 48.8 ± 2.8% (dry matter basis). The average sorghum DEF was 84% of the DEF of a composite sample of 60 corn hybrids simultaneously cultivated, ensiled and ruminally incubated. The 12 forage-type cultivars were taller, more productive, had higher fiber content and lower DEF than the 6 grain and dual purpose-type cultivars. The acid detergent fiber content had the greatest correlation with DEF (r= -0.64). The linear model correlating DEF with productivity was: DEF=54.694 - 0.4449 x t of dry matter ha-1 (r²=0.14). Although there are cultivars that show high productivity and digestibility, it seems to be difficult to conciliate the maximum nutritive value with the maximum productivity of the sorghum crop.Forrageiras para alimentação de vacas leiteiras devem conciliar a alta produção de matéria seca por área, maximizando a taxa de lotação animal, com o alto valor nutritivo, capaz de reduzir a necessidade de alimentos concentrados por litro de leite produzido. Dezoito cultivares de sorgo foram cultivados com espaçamento de 0,70 m e 12 plantas por metro linear. As plantas colhidas ao atingirem o estádio leitoso-pastoso foram ensiladas em laboratório. Onze características agronômicas e químicas foram avaliadas. As silagens foram incubadas in situ e a degradabilidade efetiva da matéria seca no rúmen (DEF) foi calculada assumindo uma taxa de passagem de -0,04 h-1. A produção de matéria seca foi 13,0 ± 2,3 (média ± D.P.) t ha-1. O teor de fibra em detergente neutro foi 50,3 ± 3,8 e a DEF foi 48,8 ± 2,8 (% da matéria seca). A DEF média do sorgo foi 84% da DEF de uma amostra composta de 60 cultivares de milho simultaneamente cultivados, ensilados e incubados no rúmen. Os 12 cultivares do tipo forrageiro foram mais altos, produtivos e fibrosos e tiveram menor DEF que os 6 cultivares graníferos e de duplo propósito. O teor de fibra em detergente ácido foi a característica mais correlacionada à DEF (r=-0,64). O modelo linear correlacionando a DEF à produtividade foi: DEF=54,69 - 0,4449 x t de matéria seca ha-1 (r²=0,14). Apesar de existirem cultivares com alta produtividade e digestibilidade, pode ser difícil conciliar o máximo valor nutritivo com a máxima produtividade na planta de sorgo

Circulating cell-free DNA methylation mirrors alterations in cerebral patterns in epilepsy

Background: DNA methylation profiling of circulating cell-free DNA (cfDNA) has rapidly become a promising strategy for biomarker identification and development. The cell-type-specific nature of DNA methylation patterns and the direct relationship between cfDNA and apoptosis can potentially be used non-invasively to predict local alterations. In addition, direct detection of altered DNA methylation patterns performs well as a biomarker. In a previous study, we demonstrated marked DNA methylation alterations in brain tissue from patients with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). Results: We performed DNA methylation profiling in cfDNA isolated from the serum of MTLE patients and healthy controls using BeadChip arrays followed by systematic bioinformatic analysis including deconvolution analysis and integration with DNase accessibility data sets. Differential cfDNA methylation analysis showed an overrepresentation of gene ontology terms and transcription factors related to central nervous system function and regulation. Deconvolution analysis of the DNA methylation data sets ruled out the possibility that the observed differences were due to changes in the proportional contribution of cortical neurons in cfDNA. Moreover, we found no overrepresentation of neuron- or glia-specific patterns in the described cfDNA methylation patterns. However, the MTLE-HS cfDNA methylation patterns featured a significant overrepresentation of the epileptic DNA methylation alterations previously observed in the hippocampus. Conclusions: Our results support the use of cfDNA methylation profiling as a rational approach to seeking non-invasive and reproducible epilepsy biomarkers.This study has been supported by R+D+i project PID2020-117212RB-I00 funded by MCIN/AEI/10.13039/501100011033. This work has also been par‑ tially supported by a BICE Tecnifar Grant. RM-F is funded by an FCT (Fundação para a Ciência e Tecnologia) fellowship (SFRH/BD/137900/2018). UMIB is funded by FCT Portugal (UIDB/00215/2020 and UIDP/00215/2020) and ITR (LA/P/006/2020).info:eu-repo/semantics/publishedVersio

Natural and synthetic compounds as anti-cancer therapies for breast and prostate cancer

Breast Cancer (BCa) and Prostate Cancer (PCa) are the most prevalent tumors in females and males, respectively, being the main causes of cancer morbidity and mortality, worldwide. Currently, there is no available curative treatment for the hormone-resistant tumors, being the development of new therapeutic strategies using innovative anticancer agents imperative. Thus, the main goal of this work was to evaluate the anticancer properties of natural and synthetic compounds through in vitro assays.info:eu-repo/semantics/publishedVersio

Reactivity of paraquat with sodium salicylate: formation of stable complexes

Sodium salicylate (NaSAL) has been shown to be a promising antidote for the treatment of paraquat (PQ) poisonings. The modulation of the pro-oxidant and pro-inflammatory pathways, as well as the antithrombogenic properties of NaSAL are probably essential features for the healing effects provided by this drug. Nevertheless, a possible direct chemical reactivity between PQ and NaSAL is also a putative pathway to be considered, this hypothesis being the ground of the present study. In accordance, it is shown, for the first time that PQ and NaSAL react immediately in aqueous medium and within 2–3 min in the solid state. Photographs and scanning electron photomicrographs indicated that a new chemical entity is formed when both compounds are mixed. This assumption was corroborated by the evaluation of the melting point, and through several analytical techniques, namely ultraviolet/visible spectroscopy, nuclear magnetic resonance spectroscopy, gas chromatography/mass spectrometry/mass spectrometry (GC/MS/MS), liquid chromatography/electrospray ionization/mass spectrometry/mass spectrometry (LC/ESI/MS/MS) and infrared spectroscopy, which revealed that stable charge-transfer complexes are formed when PQ is mixed with NaSAL. LC/ESI/MS/MS allowed obtaining the stoichiometry of the charge-transfer complexes. In order to increase resolution, single value decomposition, acting as a filter, showed that the chargetransfer complexes withm/z 483, 643 and 803 correspond to the pseudo-molecular ions, respectively 1:2, 1:3 and 1:4 (PQ:NaSAL). In conclusion, these results provided a new and important mechanism of action of NaSAL against the toxicity mediated by PQ