Thermo-mechanical stability of a cellular assembly of carbon nanotubes in air

Carbon nanotubes (CNT) in bulk form offer outstanding structural and functional properties, and are shown to remain viscoelastic over a wide temperature range (77-1273 K) under inert conditions. We examine the quasi-static and dynamic compressive mechanical response of these cellular CNT materials in ambient air up to a temperature of 773 K. In uniaxial quasi-static compression, several displacement bursts are noted at large strains. These are results of the slippage and zipping of the CNT, and lead to significant mechanical energy absorption. Results of the dynamic mechanical analysis experiments show no degradation in storage modulus and loss coefficient for up to 20 h at 673 K. Hence, these stable cellular CNT structures can be utilized up to a maximum temperature of 673 K in air, which is much higher than the best polymers. (C) 2012 Elsevier Ltd. All rights reserved

A clinical study to compare the efficacy and safety of pregabalin sustained release formulation with pregabalin immediate release formulation in patients of diabetic peripheral neuropathic pain

Objective: To compare the efficacy and safety of sustained release (SR) formulation of pregabalin with immediate release (IR) formulation in patient with diabetic peripheral neuropathic pain. Materials and Methods: In this open label, randomized, comparative, multicentric study, the primary efficacy measure was reduction in visual analogue scale (VAS) of short form McGill pain questionnaire (SF-MPQ) score from baseline to last visit. The secondary evaluation measures included reduction in SF-MPQ descriptive score and present pain intensity score and change in clinical global impression - improvement of illness (CGI-I) and clinical global impression - severity of illness (CGI-S) from baseline to last visit. Total duration of the study was 12 weeks. Safety evaluation was done by recording treatment emergent adverse events and laboratory investigations at baseline and end of treatment. Results: Of 265 randomized patients, 133 received pregabalin SR tablets and 132 pregabalin IR. Patients randomized to both treatments responded to respective treatments. The least square means of VAS score in both the groups were reduced significantly (P <0.01). Reduction in both groups was similar (P = ns). At the end of the trial in both the groups, there was a significant reduction in the SF-MPQ descriptive score (P <0.01), severity of illness as well as clinically significant improvement in the symptoms. Difference between the groups for CGI-I (P = 0.37) and CGI-S (P = 0.41) score was not statistically significant. Treatment in both the groups was found safe and well tolerated. Conclusion: The study shows that the pregabalin SR is safe and effective in patients of diabetic peripheral neuropathic pain. The results of the study demonstrated that pregabalin SR has comparable efficacy and safety as pregabalin IR