1 to 3 wt %, are prepared by dilution of a polypropylene based masterbatch (20% MWCNT) with isotactic polypropylene (iPP) using extrusion processing. CNT are found to enhance significantly the thermal stability of iPP in nitrogen and air atmosphere. Dynamic mechanical analysis and tensile tests confirm the reinforcement effect of small amount of nanotubes in iPP.
Rheology, structure, and properties are correlated determine the optimal limits of nanofiller content required for improving the performance of nanocomposites. The rheological flocculation threshold of phi* = 0.5% is found as a critical concentration for the formation of a flocculated type of structure in the dispersions. It is proposed, that the flocculated structure is responsible for the maximal improvement of nanocomposite learn more mechanical and thermal properties. The MWCNT additive slightly enhances the local dynamics of iPP molecules in the glass transition region and suppresses the global relaxation of the chain segments in the amorphous regions, resulting in a reinforcement effect. The fracture mechanism is discussed and associated with the hierarchy of the flocculated nanocomposite morphology and the bridging of matrix cracks by CNT. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115: 3576-3585, 2010″
“HIV
and tuberculosis ( TB) are leading global causes of mortality MK5108 supplier and morbidity. Highly active antiretroviral therapy ( HAART) is often initiated in patients being treated for TB. The immune recovery associated with HAART results in dramatic clinical benefits, but this restoration of immunity may result in immunopathological reactions. The immune reconstitution inflammatory syndrome can result in fever, nodal enlargement, and worsening pulmonary infiltrates observed on a chest radiograph, with or without recurrent respiratory symptoms. Several other manifestations have also been described. APR-246 As a consequence, the use of HAART might not be appropriate
during the. first weeks of anti-TB therapy in HIV-infected patients. In this review, we summarize the incidence, clinical presentations, and potential mechanisms of these conditions and we describe therapeutic methods. (C) 2009 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.”
“Calcium hydroxide dressing residuals can compromise endodontic sealing. This study evaluated the cleaning efficacy of different endodontic irrigants in removing calcium hydroxide by SEM image analysis. Fifty-four single-rooted mandibular premolars were instrumented to a master apical file #60 and dressed with calcium hydroxide. After 36 hours, the teeth were reopened and Ca(OH)(2) medication was removed by 5 different experimental groups: 0.5% NaOCl (G1), EDTA-C (G2), citric acid (G3), EDTA-T (G4), and re-instrumentation with MAF using NaOCl and lubrificant, followed by EDTA-T (G5).