Oxygen plasma treatment of sisal fibers and polypropylene: Effects on mechanical properties of composites

Polypropylene powder and sisal fibers were oxygen plasma treated, and the mechanical properties of their composites were tested. Two main effects were investigated: the incorporation of oxygen polar groups in the polypropylene surface and the surface degradation and chain scission of both polypropylene and sisal fibers. Prior to these treatments, three reactor configurations were tested to investigate the best condition for both effects to occur in PP film. Results showed that polypropylene-cellulose adhesion forces are about an order of magnitude higher for PP film treatments at 13.56 MHz than at 40 kHz owing to much higher chain scission at lower frequencies, although it probably also occurs at high frequency and high power. Polypropylene powder treated with oxygen plasma in optimum conditions for polar group incorporation did not result in improvement in any composite mechanical property, probably owing to the polymer melting. Sisal fibers and PP powder treated In conditions of surface degradation did not improve flexural or tensile properties but resulted in higher impact resistance, comparable to the improvement obtained with the addition of compatibilizer.

Synthesis and crystal phase evaluation of hydroxylapatite using the rietveld-maximum entropy method

Bioceramic systems based on hydroxylapatite (HAP) are an important class of bioactive materials that may promote bone regeneration. The aim of this research was to evaluate how the stoichiometry of HAP influences its microstructural properties when diagnosed using the combined Rietveld method and Maximum entropy method (MEM). The Rietveld Method (RM) is recognizably a powerful tool used to obtain structural and microstructural information of polycrystalline samples analyzed by x-ray diffraction. Latterly have combined the RM with the maximum entropy method (MEM), with the goal of improve structural refinement results. The MEM provides high resolution maps of electron density and their analysis leave the accurate localization of atoms inside of unit cell. Like that, cycles Rietveld-MEM allow an excellent structural refinement In this work, a hydroxylapatite sample obtained by emulsion method had its structure refined using one cycle Rietveld-MEM with x-ray diffraction data. The indices obtained in initial refinement was Rwp = 7.50%, Re = 6.56%, S - 1.14% e RB = 1.03%. After MEM refinement and electron densities maps analysis to correction of atomics positions, the news indicators of Rietveld refinement quality was Rwp = 7.35%, Re = 6.56%, S = 1.12% and RB = 0.75%. The excellent result obtained to RB shows the efficiency of MEM as auxiliary in the refinement of structure of hydroxylapatite by RM.

A Pilot Study Addressing the Impact of Religious Practice on Quality of Life of Breast Cancer Patients During Chemotherapy

The aim of this preliminary study was to investigate whether religious practice can modify quality of life (QoL) in BC patients during chemotherapy. QoL and religion practice questionnaire (RPQ) scores were evaluated in a sample of BC patients in different moments. Before chemotherapy initiation, women with lower physical and social functional scores displayed higher RPQ scores. On the other hand, low RPQ patients worsened some QoL scores over time. Body image acceptance was positively correlated with religious practice and specifically praying activity. This preliminary study suggests the importance of religion in coping with cancer chemotherapy. © 2011 Springer Science+Business Media, LLC.

Spirituality: Do teachers and students hold the same opinion?

Background:  Few studies have investigated potential differences between the opinions of educators and undergraduates regarding spirituality in patient care. Understanding these differences, could lead to better strategies for educational proposes. Purpose:  To compare the opinions of medical teachers (MTs) and medical students (MSs) regarding spirituality training in a Brazilian medical school. Methods:  A cross-sectional study was conducted. MTs and MSs filled out a questionnaire containing the Duke Religion Index, and questions regarding spirituality in clinical practice and at medical school. A comparison between early-curriculum MSs, late curriculum MSs and MTs was carried out. Chi-square (categorical) and Mann-Whitney (continuous/ordinal) tests were used. Results:  A total of 475 MSs and 44 MTs were evaluated. Results showed that MSs did not address spirituality as frequently as MTs (p<0.001), and that most participants did not feel prepared to address this issue, and believe that Brazilian medical schools are not giving all the required information in this field. Nevertheless, they believe MSs should be prepared to discuss these issues. Late-curriculum MSs believed that spirituality plays a more positive role in patient health (p=0.027), and were more prone to address this issue than early-curriculum MSs (p=0.023). Conclusion:  These findings revealed some of the challenges faced by spirituality medical training in Brazil, and differences between MTs and MSs regarding this issue. Further studies are needed to replicate these findings in other countries. © Blackwell Publishing Ltd 2013.