Nanoscale control of Ag nanostructures for plasmonic fluorescence enhancement of near-infrared dyes

Potential utilization of proteins for early detection and diagnosis of various diseases has drawn considerable interest in the development of protein-based detection techniques. Metal induced fluorescence enhancement offers the possibility of increasing the sensitivity of protein detection in clinical applications. We report the use of tunable plasmonic silver nanostructures for the fluorescence enhancement of a near-infrared (NIR) dye (Alexa Fluor 790). Extensive fluorescence enhancement of ∼2 orders of magnitude is obtained by the nanoscale control of the Ag nanostructure dimensions and interparticle distance. These Ag nanostructures also enhanced fluorescence from a dye with very high quantum yield (7.8 fold for Alexa Fluor 488, quantum efficiency (Qy) = 0.92). A combination of greatly enhanced excitation and an increased radiative decay rate, leading to an associated enhancement of the quantum efficiency leads to the large enhancement. These results show the potential of Ag nanostructures as metal induced fluorescence enhancement (MIFE) substrates for dyes in the NIR “biological window” as well as the visible region. Ag nanostructured arrays fabricated by colloidal lithography thus show great potential for NIR dye-based biosensing applications

Multiplexed five-color molecular imaging of cancer cells and tumor tissues with carbon nanotube Raman tags in the near-infrared

Single-walled carbon nanotubes (SWNTs) with five different C13/C12 isotope compositions and well-separated Raman peaks have been synthesized and conjugated to five targeting ligands in order to impart molecular specificity. Multiplexed Raman imaging of live cells has been carried out by highly specific staining of cells with a five-color mixture of SWNTs. Ex vivo multiplexed Raman imaging of tumor samples uncovers a surprising up-regulation of epidermal growth factor receptor (EGFR) on LS174T colon cancer cells from cell culture to in vivo tumor growth. This is the first time five-color multiplexed molecular imaging has been performed in the near-infrared (NIR) region under a single laser excitation. Near zero interfering background of imaging is achieved due to the sharp Raman peaks unique to nanotubes over the low, smooth autofluorescence background of biological species.Comment: Published in Nano Researc

Promoção da saúde da mulher brasileira e a alimentação saudável: vozes e discursos evidenciados pela Folha de SP

Resumo O estudo identifica discursos e vozes sobre saúde da mulher no que se refere à sua alimentação, por meio de pesquisa qualitativa utilizando o método de análise do discurso jornalístico do impresso Folha de São Paulo. A partir da seleção dos textos sobre saúde, saúde da mulher e alimentação, publicados ao longo do ano de 2013, a amostra resultou em sete textos jornalísticos, nos quais foram identificadas predominantemente vozes provenientes do universo científico relacionadas a pesquisas, citação de periódicos, associações científicas e falas de profissionais da saúde e pesquisadores. Entretanto, as falas de cidadãs comuns pouco apareceram na amostra analisada. Nos conteúdos predominaram o discurso relacionado ao risco à saúde e sua relação com a prática alimentar, nutricional ou de suplementação, como também à gravidez e/ou ao tipo de parto; a saúde como mercadoria associada a produtos ou procedimentos, como dietas, suplementos alimentares, medicamentos e cirurgia bariátrica, sem espaço para a promoção da saúde e alimentação saudável

Brain-derived Neurotrophic Factor and Epilepsy—A Missing Link?

It has been known for some time that brain-derived neurotrophic factor (BDNF) is critical to normal development of the CNS, and more recently, studies also have documented the ability of BDNF to modify adult CNS structure and function. Therefore, it is no surprise that BDNF has been linked to diseases, such as epilepsy, which may involve abnormal cortical development or altered brain structure and function after maturity. This review evaluates the evidence, particularly from recent studies, that BDNF contributes to the development of temporal lobe epilepsy (TLE)