Abstract Public universities, and science in general, in Brazil, are under attack from key persons of the government in interviews and articles published in non-scientific journals. Here we look at bibliography data from international science metric platforms (Scival® and Incites®) and official Brazilian agencies such as CAPES and CNPq to reach some conclusions based on scientific analysis. Brazilian Science has shown a steady improvement in quantity and quality over the last 20 years but has recently suffered (since 2015) under severe financial restrictions. An increase in international collaboration also increased citation impact, reaching almost five times the world average. While the medical and natural sciences show the highest impact and prominence, social sciences and the humanities also have spotlight areas with international excellence. Different research institutions and universities offer a variety of production profiles and impacts. This diagnosis shows the need for universities and research institutes in Brazil and funding agencies to undergo strategic planning for definition of mission/vision, goals to be reached, and areas for priority development. Continued support of public universities by the government is necessary for Brazilian autonomy in science and technology and its full integration in the world scientific community.

Nanopartículas mesoporosas de sílica são conhecidas por induzirem hemólise de células vermelhas do sangue (RBCs) humano quando ensaios de citotoxicidade são feitos em solução-tampão de fosfato (PBS). Entretanto, em uma abordagem mais realista, a presença de biomoléculas do plasma sanguíneo precisa ser considerada em qualquer avaliação nanotoxicológica de nanopartículas porosas de SiO2 quando se objetiva a sua utilização em aplicações biomédicas através de administração intravenosa. Nesse contexto, demonstrou-se neste trabalho que nanopartículas porosas de sílica não induzem nenhum efeito citotóxico em células vermelhas do sangue quando ensaios de hemólise são feitos na presença de plasma sanguíneo, independentemente da carga superficial (positiva ou negativa) da nanopartícula. A ausência de hemólise está principalmente associada à adsorção de proteínas do plasma sobre a superfície das nanopartículas, levando à formação de um recobrimento proteico estável (denominado protein corona ou PC) que blinda o ambiente microquímico original das nanopartículas.

Mesoporous silica nanoparticles are known to induce the hemolysis of human red blood cells (RBCs) when citotoxicity assays are performed in a phosphate buffer solution (PBS). However, in a more realistic approach, the presence of blood plasma biomolecules must be considered in any nanotoxicological evaluation of porous SiO2 nanoparticles when biomedical applications through intravenous administration are aimed. In this context, it is demonstrated in this work that porous silica nanoparticles do not induce any cytotoxic effect on RBCs when hemolysis assay is done in the presence of blood plasma, regardless the surface charge (positive or negative) of the nanoparticle. The absence of hemolysis is mainly associated with the adsorption of plasma proteins on the nanoparticle surface, which leads to the formation of a stable protein coating (called protein corona or PC) that shields the original microchemical environment of bare nanoparticles.

Este trabalho relata o estudo das propriedades estruturais, morfológicas e vibracionais dos nanotubos e das nanofitas de titanato obtidos a partir de estruturas bidimensionais por meio de tratamento hidrotérmico do TiO2 em solução aquosa de NaOH. As propriedades físicas destas nanoestruturas, como preparadas e tratadas termicamente, são discutidas e comparadas com seus similares "bulks" (Na2Ti3O7 e Na2Ti6O13). Os resultados obtidos por várias técnicas de caracterização nos permitem concluir que as paredes dos nanotubos e das nanofitas, como preparados, são isoestruturais ao composto Na2Ti3O7. Contudo, nos nanotubos as ligações químicas são deformadas por causa da curvatura das paredes, enquanto nas nanofitas as camadas apresentam apenas uma desordem estrutural provocada pelo efeito de tamanho. As características térmicas das nanofitas são similares àquelas observadas para os nanotubos, nos quais as mudanças estruturais e morfológicas levam para a formação de grandes bastões (bulks) com uma mistura de fase Na2Ti3O7 e Na2Ti6O13. Concluímos que os nanotubos e as nanofitas de titanato têm a mesma composição química, igual a Na2-xHxTi3O7·nH2O (0 < x < 2). Também podemos sugerir que a espectroscopia Raman pode ser usada para uma fácil e rápida identificação das mudanças morfológicas e estruturais das nanoestruturas de titanato.

This work reports the structural, morphological and vibrational properties of titanate nanotubes and nanoribbons obtained from bidimensional structures by hydrothermal treatment of TiO2 in aqueous NaOH solutions. The physical properties of these as-synthesized and heat-treated nanostructures are discussed in comparison with their bulk (Na2Ti3O7 and Na2Ti6O13) counterparts. The results obtained from several characterization techniques allowed to conclude that the layers of both as-synthesized nanotubes and nanoribbons are isostructural to the Na2Ti3O7 compound. However, in the nanotubes, the chemical bonds are deformed because of the curvature of walls while in the nanoribbons the layers present structural disorder due only the size effects. The thermal behavior of titanate nanoribbons is similar to those observed for titanate nanotubes. When thermally treated titanate nanoribbons change to bulk with a phase mixing of Na2Ti3O7 and Na2Ti6O13. We conclude in this work that the chemical composition of both the titanate nanotubes and the nanoribbons is the same, Na2-xHxTi3O7·nH2O (0 < x < 2) and Raman spectroscopy can be used for an easy and quick identification of both morphology and structure changes of the nanosized titanates.