Editorial

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Etching Technique For Transmission Electron Microscopy Observation Of Nanostructure Of Visible Luminescent Porous Silicon

We present a special configuration for the electrochemical etching of silicon, in which thin samples suitable for direct transmission electron microscopy observation are produced. This technique allows the observation of images of an irregular matrix of pores and individual columnlike structures with a ∼15 Å cross-sectional diameter. These images show that the preferential etching directions are the projections of the {100} planes on the (111) plane for the etched <111≳-oriented silicon. The large pore (≳50 nm diam) axis orientation is independent of the preferential etching direction and is parallel to the etching current direction.63101348135

PS-HEMA latex fractionation by sedimentation and colloidal crystallization

A poly(styrene-co-hydroxyethylmethacrylate) latex underwent sedimentation under gravity followed by an spontaneous and extensive colloidal crystallization. It was then fractionated in three visually distinguishable layers. Latex aliquots layers were sampled at different heigths and the particles were characterized by PCS, microelectrophoresis, infrared spectra and analytical electron microscopy. The major fraction was opalescent and contained the colloidal crystals settled in the bottom of the liquid. Two other latex fractions were obtained, which differed in their chemical compositions, particle sizes and topochemical features from the self-arraying particles. Macrocrystallization of the fractionated latex yielded high quality crystals with a low frequency of defects, which confirms that particle chemical homogeneity is an important factor for particle self-arraying.Látex de poli(estireno-co-hidroxiacrilato de metila) separa-se em três camadas visualmente distinguíveis, das quais a inferior é opalescente e contém cristais coloidais. Alíquotas do látex foram coletadas em diferentes alturas, e as partículas foram caracterizadas, por espalhamento de luz dinâmico, microeletroforese, IV e microscopia eletrônica analítica. A fração inferior contém a maior parte do polímero, sendo formada por partículas de dimensões e composição química uniformes. As partículas coletadas das duas outras frações são diferentes das que formam os cristais coloidais, em praticamente todos os aspectos. A secagem da fração opalescente produz macrocristais de alta qualidade, com baixa frequência de defeitos, mostrando que a homogeneidade química das partículas é um fator importante, na sua auto-organização.497504Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Innovation for sustainability

The transition to sustainable standards of production and consumption within a scenario of decreased availability of natural resources, growing population and climate change is essential to meet current challenges facing mankind. A strategy to meet these challenges should contain elements different from current approaches for industrial production. This work concentrates on the possibilities for the intensive use of sustainable biomass, abundant minerals and every type of residue, a task that can largely benefit from the application of nanotechnology and biotechnology platforms for material design and transformation. This strategy cannot be solely based on existing knowledge and requires new science, new knowledge including supposedly well-known themes, like the tribochemistry of electrostatic charging and friction. It is especially relevant within the Brazilian context, where many recent successful innovations are related to biomass production and transformation. Implementation of this strategy requires converging efforts by personnel from many different organizations and professions, while making sound risk assessment to produce significant innovation leading to sustainable development.16001604Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Inovação para a sustentabilidade

The transition to sustainable standards of production and consumption within a scenario of decreased availability of natural resources, growing population and climate change is essential to meet current challenges facing mankind. A strategy to meet these challenges should contain elements different from current approaches for industrial production. This work concentrates on the possibilities for the intensive use of sustainable biomass, abundant minerals and every type of residue, a task that can largely benefit from the application of nanotechnology and biotechnology platforms for material design and transformation. This strategy cannot be solely based on existing knowledge and requires new science, new knowledge including supposedly well-known themes, like the tribochemistry of electrostatic charging and friction. It is especially relevant within the Brazilian context, where many recent successful innovations are related to biomass production and transformation. Implementation of this strategy requires converging efforts by personnel from many different organizations and professions, while making sound risk assessment to produce significant innovation leading to sustainable development

SUR1 Receptor Interaction with Hesperidin and Linarin Predicts Possible Mechanisms of Action of Valeriana officinalis in Parkinson.

Parkinson's disease (PD) is one of the most common neurodegenerative disorders. A theoretical approach of our previous experiments reporting the cytoprotective effects of the Valeriana officinalis compounds extract for PD is suggested. In addiction to considering the PD as a result of mitochondrial metabolic imbalance and oxidative stress, such as in our previous in vitro model of rotenone, in the present manuscript we added a genomic approach to evaluate the possible underlying mechanisms of the effect of the plant extract. Microarray of substantia nigra (SN) genome obtained from Allen Brain Institute was analyzed using gene set enrichment analysis to build a network of hub genes implicated in PD. Proteins transcribed from hub genes and their ligands selected by search ensemble approach algorithm were subjected to molecular docking studies, as well as 20 ns Molecular Dynamics (MD) using a Molecular Mechanic Poison/Boltzman Surface Area (MMPBSA) protocol. Our results bring a new approach to Valeriana officinalis extract, and suggest that hesperidin, and probably linarin are able to relieve effects of oxidative stress during ATP depletion due to its ability to binding SUR1. In addition, the key role of valerenic acid and apigenin is possibly related to prevent cortical hyperexcitation by inducing neuronal cells from SN to release GABA on brain stem. Thus, under hyperexcitability, oxidative stress, asphyxia and/or ATP depletion, Valeriana officinalis may trigger different mechanisms to provide neuronal cell protection.Fil: Santos, Gesivaldo. Universidade Estadual do Sudoeste da Bahia; BrasilFil: Giraldez Alvarez, Lisandro Diego. Universidade Estadual do Sudoeste da Bahia; BrasilFil: Ávila Rodriguez, Marco. Pontificia Universidad Javeriana; ColombiaFil: Capani, Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; ArgentinaFil: Galembeck, Eduardo. Universidade Estadual de Campinas; BrasilFil: Gôes Neto, Aristóteles. Universidade Estadual de Feira de Santana; BrasilFil: Barreto, George E.. Pontificia Universidad Javeriana; ColombiaFil: Andrade, Bruno. Universidade Estadual do Sudoeste da Bahia; Brasi

Supramolecular ionics: electric charge partition within polymers and other non-conducting solids

Electrostatic phenomena in insulators have been known for the past four centuries, but many related questions are still unanswered, for instance: which are the charge-bearing species in an electrified organic polymer, how are the charges spatially distributed and which is the contribution of the electrically charged domains to the overall polymer proper-ties? New scanning probe microscopies were recently introduced, and these are suitable for the mapping of electric potentials across a solid sample thus providing some answers for the previous questions. In this work, we report results obtained with two of these techniques: scanning electric potential (SEPM) and electric force microscopy (EFM). These results were associated to images acquired by using analytical electron microscopy (energy-loss spectroscopy imaging in the transmission electron microscope, ESI-TEM) for colloid polymer samples. Together, they show domains with excess electric charges (and potentials) extending up to hundreds of nanometers and formed by large clusters of cations or anions, reaching supramolecular dimensions. Domains with excess electric charge were also observed in thermoplastics as well as in silica, polyphosphate and titanium oxide particles. In the case of thermoplastics, the origin of the charges is tentatively assigned to their tribochemistry, oxidation followed by segregation or the Mawell-Wagner-Sillars and Costa Ribeiro effects.73449551

Editorial: challenges, plans and action

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Processo De Fabricação De Adesivo Para Superficìes De Vidros, Cerâmicas, Alvenarias E Plásticos à Base De Látex De Borracha Natural Modificado Por Polifosfato

A presente invenção se refere a um processo de preparação de filmes adesivos a superfícies de vidro, cerâmicas, alvenarias e plásticos a partir de látex de borracha natural e polifosfato de sódio. Os processos atuais de fabricação de adesivos de borracha natural envolvem a utilização de solventes, reações químicas com variados monômeros como acrílico, estireno, butadieno entre outros, organometálicos, polimerização e enxertia com outros polímeros, o que resulta no encarecimento do produto final, além de contribuir para a degradação do meio ambiente. As principais superfícies de aplicação destes adesivos são: papel, concreto, couro, borrachas e plásticos. Esta invenção descreve o processo de fabricação de um adesivo à base de látex natural, em meio alcalino, com a adição de polifosfato, à temperatura ambiente e sob agitação. Este adesivo apresenta grande molhabilidade, alta adesão e poder de cobertura em superfícies de vidros, cerâmicas, alvenaria e plásticos. Além disso é um produto à base de água e é biodegradável, não sendo prejudicial ao meio ambiente.BR0102823C09J107/02C09J107/02BR20010102823C09J107/02C09J107/0