Digital electric field induced switching of plasmonic nanorods using an electro-optic fluid fiber

We demonstrate the digital electric field induced switching of plasmonic nanorods between 1 and 0 orthogonal aligned states using an electro-optic fluid fiber component. We show by digitally switching the nanorods, that thermal rotational diffusion of the nanorods can be circumvented, demonstrating an approach to achieve submicrosecond switching times. We also show, from an initial unaligned state, that the nanorods can be aligned into the applied electric field direction in 110 nanoseconds. The high-speed digital switching of plasmonic nanorods integrated into an all-fiber optical component may provide novel opportunities for remote sensing and signaling applications

Feminist Activism Through the Arts in Late 19th Century and Early 20th Century. A Diachronic Comparative Study Between Portugal And Brazil

Brazil and Portugal are two countries that, although geographically located on different continents, share a history (from 1500 to 1822 when Brazil was a Portuguese colony) and the same language (Portuguese), and both have very high rates of domestic violence and situations of gender inequality. Growing fundamentalist and ultraconservative parties around the world are threatening gender equality and women’s conquest for rights. In Portugal and Brazil, new parties with extremist discourses and ideologies that perpetuate patriarchal societies are also growing. It is crucial to continue breaking paradigms and remembering history, particularly the moments marked by the struggle for human rights. Many women have fought for their rights, advocated for gender equality, and worked toward building women’s citizenship in and through education. Looking particularly at Brazil’s post-independence period, we conducted a diachronic comparative study of feminist activist artists from these two countries and found inspiring examples of feminine resistance and resilience. We analysed different female approaches that surprised us with their originality and creativity. We looked at the similarities and differences between how Portuguese and Brazilian women with access to culture and art—painting, music, literature, etc.—positioned and manifested themselves in the face of these social and cultural inequalities in the late 19th and early 20th centuries. The women artists that we studied have reached professional status as artists, which has allowed them to become financially independent. Thus, they have been able to leave the private sphere and enter the public and international sphere

Bleaching of sol-gel glass film with embedded gold nanoparticles by thermal poling

Gold clusters embedded in glass are expected to be hard to dissolve in the form of ions since gold is essentially a nonreactive metal. In spite of that, bleaching of Au-doped nanocomposite sol-gel glass film on a soda-lime glass substrate is demonstrated in which electric-field thermal poling is employed to effectively dissolve randomly distributed gold nanoparticles (15 nm in diameter) embedded in a low conductivity sol-gel glass film with a volume filling factor as small as 2.3%. The surface plasmon absorption band at 520 nm is suppressed in the region covered by the anodic electrode. The phenomenon is explained by the ionization of the gold nanoparticles and the redistribution of gold ions in the glass matrix due to the action of the extremely high electrostatic field locally developed during poling

Evaluation of antioxidant activity of selected Brazilian plants extracts

Numerous diseases are induced by free radicals and it has long been recognized that naturally occurring substances in higher plants have antioxidant activityinfo:eu-repo/semantics/publishedVersio

Mulheres Licenciadas e a Promoção do Desenvolvimento em Angola: Que diferença faz o Ensino Superior?

A educação é um direito universal e uma ferramenta fundamental para o desenvolvimento das capacidades dos indivíduos e da sociedade. Em Angola, baixas taxas de qualificação da população estão associadas com as mais altas taxas de pobreza e exclusão social, desemprego, analfabetismo, mortalidade infantil, incidência de HIV, malária e tuberculose, entre outras. Níveis mais elevados de educação promovem maior bem-estar e qualidade de vida, por via dos rendimentos auferidos e, mulheres mais qualificadas terão tendência a melhorar o seu estatuto na sociedade e a modificar o seu estilo de vida. Por outro lado é expectável que motivem, de forma natural, à sua descendência a importância da aprendizagem e da aquisição de conhecimentos. Esta questão é particularmente pertinente em sociedades onde as mulheres desempenham um papel determinante na economia. Do ponto de vista da sustentabilidade dos territórios, podem contribuir ainda para a construção de uma sociedade mais sustentável. O presente trabalho tem como objectivo identificar a importância da obtenção de uma licenciatura na valorização social e económica das mulheres angolanas e, consequentemente na promoção do desenvolvimento da sociedade. Para tal, apresentam-se os resultados preliminares de um estudo exploratório de natureza qualitativa com base numa entrevista aplicada a uma amostra de conveniência de mulheres angolanas licenciadas. Os resultados permitem aferir a importância das mulheres licenciadas na promoção do desenvolvimento em Angola e sugerem tópicos para futuras pesquisas

Actividades experimentais nas escolas através de uma interacção com a universidade

A forma como a ciência é ensinada nas escolas afecta profundamente a percepção que os estudantes têm do mundo que os rodeia e consequentemente a escolha de uma futura carreira nas ciências. Por outro lado, a abertura da escola à comunidade envolvente, proporciona as condições para a sua participação activa na vida escolar, assim como a promoção do sucesso escolar, através da formação integral dos alunos, dotando-os das competências científicas, tecnológicas e sócio-culturais necessárias a sólidas opções futuras. A química como uma ciência de cariz experimental oferece aos estudantes uma melhor compreensão dos conceitos teóricos leccionados. Este trabalho descreve actividades experimentais realizadas no âmbito de um intercâmbio entre a Escola Secundária/3 de Barcelinhos e o Departamento de Química. Os projectos desenvolvidos foram “Museu das Ciências” na disciplina de Área Projecto do 12º ano de escolaridade. A actividade A Ciência na investigação criminal foi baseada nas oficinas apresentadas no projecto Sentidos da Ciência [1]. Estas actividades experimentais executadas em colaboração entre as escolas e a universidade contribuem para uma maior motivação dos alunos, uma formação científica mais sólida e um conhecimento mais integrado

Chemical characterization of wild and commercial samples of Achillea millefolium L.

As plantas medicinais têm vindo a ser usadas desde tempos ancestrais e surgem hoje em dia como uma alternativa aos produtos sintéticos, devido à sua riqueza em compostos bioativos. Achillea millefolium L. pertence à família das Asteraceae e é vulgarmente conhecida como milefólio ou milfolhada, sendo muito comum em prados, caminhos, campos de cultivo e quintais. No presente trabalho, foram caracterizadas amostras comerciais e silvestres de A. millefolium em termos de composição nutricional e perfil em açúcares livres, ácidos orgânicos, ácidos gordos e tocoferóis, determinados por técnicas cromatográficas acopladas a diferentes detectores (HPLC -RI, HPLC -PDA, GC -FID e HPLC -fluorescência, respetivamente). Os hidratos de carbono, seguidos das proteínas, foram os macronutrientes maioritários em ambas as amostras. A amostra comercial mostrou um teor mais elevado de gordura, proteínas, cinzas, valor energético e açúcares totais A amostra silvestre revelou maior conteúdo em hidratos de carbono; também revelou a presença de rafinose, ácidos gordos polinsaturados e ácidos orgânicos. Relativamente aos tocoferóis, ambas as amostras revelaram um perfil muito semelhante, apesar da amostra silvestre ter mostrado uma maior concentração em tocoferóis totais. Os resultados obtidos são uma prova clara que as plantas usadas na medicina tradicional podem ter aplicabilidade não só em produtos caseiros mas também na indústria alimentar e farmacêutica como fonte de compostos bioativos.Medicinal plants have been used since ancient times and emerge nowadays as an alternative for synthetic products, due to their richness in bioactive compounds. Achillea millefolium L., commonly known as yarrow, belongs to the Asteraceae family being found in meadows, pathways, crop fields and homegardens. In the present work, commercial and wild samples of A. millefolium were characterized in terms of nutritional composition and free sugars, organic acids, fatty acids and tocopherols profile, determined by chromatographic techniques coupled to different detectors (HPLC -RI, HPLC -PDA, GC -FID and HPLC -fluorescence, respectively). Carbohydrates, followed by proteins, were the majority macronutrients found in both samples. The commercial sample showed a higher content of fat, proteins, ash, energy and total sugars. The wild sample revealed a higher content in carbohydrates, also showing the presence of raffinose, polyunsaturated fatty acids and organic acids. Regarding tocopherols, both samples showed a very similar profile, although the wild sample exhibited a higher content in total tocopherols. The results obtained highlight the fact that the plants used in traditional medicine may have applicability not only in homemade products but also in food and pharmaceutical industry, as a source of bioactive compounds.À Fundação para a Ciência e a Tecnologia (CIMO -PEst-OE/AGR/UI0690/2014; REQIMTE- -PEst -C/EQB/LA0006/2014), M.I. Dias (SFRH/ BD/84485/2012), R.C. Alves (SFRH/BPD/68883/2010) e L. Barros (SFRH/BPD/107855/2015).info:eu-repo/semantics/publishedVersio

Wild and commercial samples of Achillea millefolium L.: proximate composition and individual compounds obtained by chromatography

Medicinal plants have been used since ancient times and emerge nowadays as alternative to synthetic products, due to their richness in bioactive compounds. In a society that requires new and safer products, due to the growing concern with health and nutrition, medicinal plants are now being used not only in traditional medicine but also in a number of food and pharmaceutical products [1]. Achillea millefolium L., belongs to Asteraceae family and it is commonly known as yarrow, very common in mountain meadows, pathways, crop fields and homegardens. Widespread across Europe, it’s infusion, decoction and alcoholic extract are widely used as an herbal remedy to treat digestive problems, diabetes, hepato-biliary diseases and amenorrhea, showing also antitumor, antimicrobial, anti-inflammatory and antioxidant properties [2,3]. In the present work, commercial and wild samples of A. millefoilum were characterized regarding the proximate composition and individual compounds namely, free sugars, organic acids, fatty acids and tocopherols, determined by chromatographic techniques coupled to different detectors (HPLC-RI, HPLC-DAD, GC-FID e HPLC-fluorescence, respectively). Carbohydrates, followed by proteins, were the major macronutrients in both samples. Commercial yarrow gave higher content of fat (and saturated fatty acids, mainly palmitic acid C16:0), proteins, ash, energetic value and total sugars (including fructose, glucose, sucrose and trehalose). Wild sample revealed higher levels of carbohydrates; it also showed raffinose (not detected in the commercial sample), polysaturated fatty acids (mainly linoleic acid, C18:2n-6) and organic acids (including malic, oxalic and quinic acids). Regarding tocopherols, both samples showed similar profile, although the wild sample gave higher levels of total tocopherols; γ-Tocopherol was the most abundant isoform; δ-Tocopherol was not found in the samples. Data obtained are clear evidence that traditional medicinal plants can be used not only in household products but also in pharmaceutical and food industry as a source of new and safer bioactive compounds

A comparative study of bioactive properties of wild and commercial Achillea millefolium L.

Achillea millefolium L., commonly known as yarrow, is a medicinal plant with high bioactive value. Its infusion, decoction and alcoholic extract are widely used in Europe to treat digestive and intestinal problems, but also due to their antitumor, antimicrobial, anti-inflammatory and antioxidant properties [1]. In the present work, methanolic extract, infusion and decoction of wild and commercial yarrow were studied for their antioxidant properties and antitumor potential, evaluated by free radicals scavenging activity, reducing power and lipid peroxidation inhibition and by estimation of the growth inhibitory activity in human tumor cell lines, respectively. Overall, cultivated yarrow showed the highest antioxidant activity, presenting the lowest EC50 values. Decoctions of both samples revealed the highest DPPH scavenging activity (0.25 and 0.20 mg/ml, respectively), 13-carotene bleaching inhibition {0.18 and 0.22 mg/ml) and TBARS inhibition (0.04 and 0.08 mg/ml), while infusions presented the highest reducing power (0.12 and 0.13 mg/ml). The samples showed a higher lipid peroxidation inhibition, but a lower DPPH scavenging activity than methanolic extract of A. millefolium from Turkey (892.67 and 45.60 11g/ml, respectively) [2]. The infusion of wild yarrow showed the highest potential against breast (MCF-7; 8 150=17.04 1-Jg/ml) and hepatocellular (HepG2; 37.60 1-Jg/ml) carcinoma cell lines, while the methanolic extract of commercial yarrow was most potent against non-small cell lung (NCI H460; 26.64 IJg/ml), colon (HCT-15, 13.90 1-Jg/ml) and cervical (Hela, 19.68 IJg/ml) carcinoma cell lines. The results obtained with the decoction and infusion of cultivated yarrow against MCF-7 line are consistent with the ones reported with ethanolic extract of A. millefolium from Iran (8150=64 .078 1-Jg/ml) [3].This is a groundbreaking study on the comparison of different extracts of A. millefolium, showing that medicinal plants can be used not only in traditional medicine but also as a source of bioactive products, namely antioxidants and antitumorals.Foundation for Science and Technology (FCT, Portugal) for financial support to the research centre CIMO (PEst-OE/AGR/UI0690/2011 ) and REQUIMTE (PEst-C/EQB/LA0006/2011 ). M.l. Dias, L. Barros and R.C. Alves also thank to FCT, POPH-OREN and FSE for their grants (SFRH/BD/84485/2012, SFRH/BPD/4609/2008 and SFRH/BPD/68883/201 0, respectively)