ABSTRACT Introduction: This paper focuses on the synthesis, physicochemical characterization, bioactivity evaluation, and innovative applications of new biohybrid nanomaterials. Sepiolite is a nanofibrous natural silicate that represents a very attractive nanocarrier for nucleic acids delivery into cells, among other innovative applications in life sciences and biotechnology. Methods: The physicochemical characterization and the bioactivity evaluation of biohybrids were performed using advanced techniques and procedures, including AFM, TEM, Confocal Microscopy, TLVM, FTIR, Z-potential measurements, UV-vis, FACS, Western blot, RT-qPCR, among others. Results: New biohybrids were obtained, based on the assembly of nucleic acids with sepiolite nanofibers. The mechanisms of cell internalization and response to sepiolite exposure were proposed. We demonstrated that sepiolite is a promising nanocarrier for the non-viral and stable transfer of plasmid DNA into bacteria, mammalian and human cells, with an optimized efficiency. Due to its ability to bind various biomolecules, sepiolite could be used as a nanocarrier for the simultaneous vectorization of diverse biological molecules, including proteins, nucleases and antibodies. In addition, we obtain new protocols for both, strongly improving bacterial transformation efficiency, and to extract plasmids from bacteria, in a rapid, convenient and inexpensive method that doesn't require competent cell preparation, representing an advantageous alternative to onerous commercial kits. As a conclusion, Because of the low cost of sepiolite, its low toxicity, its natural fluorescence, the ease and convenience of sepiolite/DNA synthesis methods, the possibilities of improving the transfection efficiency and additional enticing future developments, sepiolite represents a very attractive nanoplatform for potential applications in nanomedicine and nanobiotechnology.

RESUMEN Introducción: Este trabajo se centró en la síntesis, caracterización físicoquímica, evaluación de su bioactividad y aplicaciones biomédicas de nuevos nanomateriales biohíbridos. La sepiolita es un silicato natural nanofibroso que presenta atractivas características como nanoportador para la liberación de ácidos nucleicos en células, entre otras aplicaciones innovadoras en el área de las ciencias de la vida y de la biotecnología. Métodos: La caracterización físico-química y evaluación biológica de los biohíbridos fue realizada usando procedimientos y técnicas novedosas, incluyendo entre otras AFM, TEM, microscopía confocal, TLVM, FTIR, Potencial Zeta, UV-vis, FACS, Western-blot, RT- qPCR. Resultados: Se obtuvieron nuevos biohíbridos mediante ensamblado de ácidos nucleicos con nanofibras de sepiolita. Se propusieron sus mecanismos de internalización y respuesta celular. Demostramos que la sepiolita es un nanoportador prometedor para la transferencia estable no-viral de ADN plasmídico en bacterias, células de mamíferos y humanas, con eficiencia optimizada. Debido a su capacidad de anclar varias biomoléculas, la sepiolita constituye también un nanoportador para la vectorización simultánea de diferentes moléculas biológicas, incluyendo proteínas, nucleasas y anticuerpos. Adicionalmente, obtuvimos nuevos protocolos para aumentar significativamente la eficiencia de transformación bacterial, y para la extracción de ADN de bacterias, mediante métodos rápidos, seguros y económicos que no requieren la preparación de células competentes, representando una ventajosa alternativa a los costosos kits comerciales. En conclusión, la sepiolita es un producto de bajo costo, baja toxicidad y fluorescencia natural, con facilidad y conveniencia en métodos de síntesis de biohíbridos sepiolita/ADN, con posibilidad de aumentar su eficiencia de transfección, que junto a potenciales desarrollos futuros, representa una atractiva nanoplataforma para aplicaciones en nanomedicina y nanobiotecnología.

ABSTRACT Wear resistance and Frictional stability are key performance requirements for brake lining. Automotive brake linings are usually made of various ingredients such as binder, filler, friction modifiers and reinforcement. Rockwool is a mineral fiber and steel fiber is a metallic fiber. In this work reinforcement fibers used are both the mineral and metallic fibers with six different composition prepared and tested. The result shows that metallic fibers should be high compared to mineral fiber for best frictional performance and wear resistance. Friction-wear properties of the reinforced samples were investigated on the cast iron disc as a counterpart using a pin on disc wear tester. The investigation confirmed that the sample with increase in steel fiber (4%, 8% and 12%) improves the wear resistance. On the other hand specimen with high content of Rockwool fiber forms an improper ratio among the other ingredients. The SEM images of the sample indicated that an increase in steel fiber higher than 12% content resulted in adhesive wear.Analysis of the experimental result shows that the sample with 12% steel fiber and 8% Rockwool fiber exhibited the optimum friction-wear behavior. Finally the effect of environment on the composites was investigated in water, salt water and oil.

In this paper, a high-friction composite material based on the combination of binder, friction modifiers, fibers and fillers is investigated. In the binder, up to 20% of phenol are replaced by cardanol with various weight ratios of 100/0, 95/5, 90/10, 85/15, 80/20. Cardanol may react both through the phenolic group and the double bond of the side chain yielding addition, condensation and polymerisation reactions that allow the synthesis of tailor-made products and polymers of high value. In the present work, mechanical, thermal and wear characteristics of cardanol based phenolic resin with organic ingredients were manufactured and tested. An analysis of microstructure characteristics of composites was carried out using scanning electron microscope. The effect of environment on the composite was investigated in water, salty water and oil. The results showed that the addition of cardanol reduces the wear resistance and increases the compressibility which reduces the noise propensity.

Ossos bovinos calcinados são utilizados na fabricação de porcelana de ossos, consistindo em mais de 50% em peso das matérias-primas. A fabricação deste tipo especial de porcelana ainda é inédita no Brasil. Neste trabalho investigou-se a influência das etapas de calcinação, moagem e lavagem sobre as características físico-químicas das partículas de cinza de ossos. Os pós calcinados a temperaturas entre 700 e 1000 ºC foram analisados quanto às suas distribuições de tamanho de partículas, composições químicas, composições de fases, densidades, área de superfície específica, grupos funcionais superficiais antes e depois de moídos e lavados. Os resultados indicam que os ossos processados nas temperaturas de 700, 800 900 e 1000 °C apresentam grande homogeneidade tanto química (composição química e mobilidade eletroforética) como física (tamanhos de partículas e composição de fases) antes e depois da moagem e lavagem. Contudo, apresentam um leve aumento no tamanho médio de partículas com o aumento de temperatura de calcinação. Outro fato relevante na qualidade da superfície do pó obtido é que estes devem ser calcinados sob atmosferas oxidantes para eliminação de espécies adsorvidas que podem prejudicar a formação de barbotinas estáveis.

Calcined bovine bones comprise the main raw material for the fabrication of bone china (more than 50 wt.%). This special kind of porcelain has never been produced in Brazil. In this paper was investigated the influence of the following preparation steps: firing, grinding, and washing of the bones, on the physicochemical characteristics of the obtained bone ash particles. Powders calcined at temperatures between 700 and 1000 ºC, washed and ground, were analyzed in terms of their particle size distribution (laser scattering), chemical composition (X-ray fluorescence), density (He picnometry), specific surface area (BET method), infrared spectroscopy (FTIR-DRIFT), and were also observed by scanning electron microscopy. The results indicated that bones processed at different temperatures exhibit great homogeneity either in chemical terms (chemical composition and electrophoretic mobility) or in physical terms (particle size and phase composition), show slight increase in particle size with increasing firing temperatures, and must be calcined under oxidizing atmospheres in order to develop good processing characteristics.

Ossos bovinos calcinados são utilizados na fabricação de porcelana de ossos (bone china), consistindo em mais de 50% em peso das matérias-primas. A fabricação deste tipo especial de porcelana ainda é inédita no Brasil. Neste trabalho investigou-se a influência das etapas de calcinação, moagem e lavagem sobre as características físico-químicas das partículas de cinza de ossos. Os pós calcinados a temperaturas entre 700 e 1000 ºC foram analisados quanto às suas distribuições de tamanho de partículas, composições químicas, composições de fases, densidades, área de superfície específica, grupos funcionais superficiais antes e depois de moídos e lavados. Os resultados indicam que os ossos processados nas temperaturas de 700, 800 900 e 1000 °C apresentam grande homogeneidade tanto química (composição química e mobilidade eletroforética) como física (tamanhos de partículas e composição de fases) antes e depois da moagem e lavagem, Contudo, apresentam um leve aumento no tamanho médio de partículas com o aumento de temperatura de calcinação. Outro fato relevante na qualidade da superfície do pó obtido é que estes devem ser calcinados sob atmosferas oxidantes para eliminação de espécies adsorvidas que podem prejudicar a formação de barbotinas estáveis.

Calcined bovine bones comprise the main raw material for the fabrication of Bone China (more than 50 wt.%). This special kind of porcelain has never been produced in Brazil. In this paper, the influence of the following preparation steps: firing, grinding, and washing of the bones, on the physicochemical characteristics of the obtained bone ash particles was investigated. Powders calcined at temperatures between 700 and 1000 ºC, washed and ground, were analyzed in terms of their particle size distribution, chemical composition (X-ray fluorescence), density (He picnometry), specific surface area (BET method), infrared spectroscopy (FTIR-DRIFT), and also in a scanning electron microscopy. The results indicated that bones processed at different temperatures exhibit great homogeneity either in chemical terms (chemical composition and electrophoretic mobility) or in physical terms (particle size and phase composition), show slight increase in particle size with increasing firing temperatures and must be calcined under oxidizing atmospheres in order to develop good processing characteristics.

This essay -which was originally published in The South Atlantic Quarterly in 1962- exposes the methodological, pragmatic, and sociological issues that classically-trained anthropologists confront when they attempt to carry out historical research. Using the ingenious device of structuring the argument as a traditional anthropological monograph of the 1950's, the author defines the "problem" -the survival of the anthropologist in the archives-, describes "the land and the people" -the academic habitat of the professional historian-, and expounds on the economic and social organization of the curious and parallel world of the social historian. The essay then closes with a reflection on the methodological and professional dynamics that separate the work of anthropologists and historians, even as common interests and perspectives provide interdisciplinary passages between both academic worlds.

El presente ensayo -publicado originalmente en The South Atlantic Quarterly en 1962- expone los problemas metodológicos, pragmáticos y sociológicos que los antropólogos, entrenados de la manera tradicional, enfrentan cuando tratan de hacer una investigación histórica. Utilizando la ingeniosa técnica de estructurar su discurso como una clásica monografía antropológica de los cincuenta, el autor define el problema -la sobrevivencia de los antropólogos en los archivos-, describe el lugar y su gente -el hábitat académico del historiador profesional- y explora la organización económica y social del curioso y paralelo mundo del historiador social. El ensayo cierra con una reflexión sobre las dinámicas metodológicas y profesionales que separan el trabajo de los antropólogos y los historiadores, marca un rumbo interdisciplinario entre ambos mundos académicos con intereses y perspectivas comunes.