ORGANOPHILIC BENTONITES BASED ON ARGENTINEAN AND BRAZILIAN BENTONITES. PART 1: INFLUENCE OF INTRINSIC PROPERTIES OF SODIUM BENTONITES ON THE FINAL PROPERTIES OF ORGANOPHILIC BENTONITES PREPARED BY SOLID-LIQUID AND SEMISOLID REACTIONS

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)This study describes the influence of the intrinsic properties of raw materials on the organophilization of bentonites from Argentinean raw sodium bentonites and Brazilian sodium activated bentonites. The organophilization was done with two methodologies: solid-liquid and semisolid reactions. Correlations between the properties of sodium and organophilic bentonites were established. The effectiveness of the treatments was verified by X-ray diffraction, swelling capacity in water and xylene and SEM to evaluate the morphology of the particles. The analysis was done before and after the modification process. The bentonites had organic cations intercalated, as shown by the increase of the basal spacings, and the organophilic character was confirmed because the bentonites showed xylene swelling capacity and particles with an expanded aspect in comparison to those of the sodium bentonites. Both methodologies were efficient to obtain organophilic clays. The organophilic bentonites obtained from raw sodium bentonites :gave better results.293525536Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

ORGANOPHILIC BENTONITES BASED ON ARGENTINEAN AND BRAZILIAN BENTONITES. PART 2: POTENTIAL EVALUATION TO OBTAIN NANOCOMPOSITES

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)This work describes the preparation of composites of polypropylene and organophilic bentonites based on Brazilian and Argentinean bentonites. During the processing of the samples in a twin screw microextruder, torque and pressures of the extruder were accompanied and the viscosity values were calculated. No significant changes in the torque, pressure and viscosity were found for composites prepared with different bentonites. The samples were characterized by XRD and TEM to evaluate the structure and dispersion of the organophilic bentonites. Composites with exfoliated, partially exfoliated and intercalated structures were obtained and correlations between the intrinsic properties of the sodium clays and organophilic bentonites and their influence on the composites were studied. The cation exchange capacity of the sodium bentonites and the swelling capacity of the organophilic bentonites were the most important properties to obtain exfoliated structures in composites. All bentonites showed the potential to obtain polymer nanocomposites, but the ones from Argentina displayed the best results.294751762Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

The Silences Framework: A Method for researching sensitive themes and marginalized health perspectives (English version)

Objective: To describe the experience of applying of The Silences Framework to underpin health research investigating Tuberculosis/HIV/AIDS coinfection . Method: The Silences Framework originally developed following a study exploring the decisions and silences surrounding black Caribbean men living in England, discussing the themes 'sexual health' and 'ethnicity'. Following this study a conceptual a theory for research on sensitive issues and health care of marginalized populations was developed called 'Screaming Silences' which forms the foundation of The Silences Framework. Screaming Silences define research areas and experiences that are poorly studied, little understood or silenced. Results: The Silences Framework supports researchers in revealing "silences" in the subjects they study - as such results may reflect how beliefs, values, and experiences of some groups influence their health. This framework provides the application of four complementary stages: working the silences, hearing silences, voicing silences and working with the silences. The analysis occurs cyclically and can be repeated as long as the silences inherent in a study are not revealed. Conclusion: this article presents The Silences Framework and the application of the notion of "sounds of silence", mapping an antiessentialist theoretical framework for its use in sensitive research in health and nursing areas, being a reference for other researchers in studies involving marginalized populations. KEYWORDS: Inequalities in health. Methods. Nursing. Coinfection. Research. Tuberculosis. Acquired immunodeficiency syndrome

Avoiding obscure topics and generalising findings produces higher impact research

Much academic research is never cited and may be rarely read, indicating wasted effort from the authors, referees and publishers. One reason that an article could be ignored is that its topic is, or appears to be, too obscure to be of wide interest, even if excellent scholarship produced it. This paper reports a word frequency analysis of 874,411 English article titles from 18 different Scopus natural, formal, life and health sciences categories 2009-2015 to assess the likelihood that research on obscure (rarely researched) topics is less cited. In all categories examined, unusual words in article titles associate with below average citation impact research. Thus, researchers considering obscure topics may wish to reconsider, generalise their study, or to choose a title that reflects the wider lessons that can be drawn. Authors should also consider including multiple concepts and purposes within their titles in order to attract a wider audience

Chromosome evolution in Cophomantini (Amphibia, Anura, Hylinae)

The hylid tribe Cophomantini is a diverse clade of Neotropical treefrogs composed of the genera Aplastodiscus, Boana, Bokermannohyla, Hyloscirtus, and Myersiohyla. The phylogenetic relationships of Cophomantini have been comprehensively reviewed in the literature, providing a suitable framework for the study of chromosome evolution. Employing different banding techniques, we studied the chromosomes of 25 species of Boana and 3 of Hyloscirtus; thus providing, for the first time, data for Hyloscirtus and for 15 species of Boana. Most species showed karyotypes with 2n = 2x = 24 chromosomes; some species of the B. albopunctata group have 2n = 2x = 22, and H. alytolylax has 2n = 2x = 20. Karyotypes are all bi-armed in most species presented, with the exception of H. larinopygion (FN = 46) and H. alytolylax (FN = 38), with karyotypes that have a single pair of small telocentric chromosomes. In most species of Boana, NORs are observed in a single pair of chromosomes, mostly in the small chromosomes, although in some species of the B. albopunctata, B. pulchella, and B. semilineata groups, this marker occurs on the larger pairs 8, 1, and 7, respectively. In Hyloscirtus, NOR position differs in the three studied species: H. alytolylax (4p), H. palmeri (4q), and H. larinopygion (1p). Heterochromatin is a variable marker that could provide valuable evidence, but it would be necesserary to understand the molecular composition of the C-bands that are observed in different species in order to test its putative homology. In H. alytolylax, a centromeric DAPI+ band was observed on one homologue of chromosome pair 2. The band was present in males but absent in females, providing evidence for an XX/XY sex determining system in this species. We review and discuss the importance of the different chromosome markers (NOR position, C-bands, and DAPI/CMA3 patterns) for their impact on the taxonomy and karyotype evolution in Cophomantini