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“Recently, the production of polymers loaded with inorganic nanomaterials has been one of the most economical techniques playing a special
role in improving the physical and mechanical properties of nanocomposites. Rubbers loaded with different concentrations of carbon nanoparticles CA4P (CNPs) were synthesized. The mechanical properties were tested according to standard methods. It was found that the properties of the investigated nanocomposites were improved, depending on the concentration of CNPs in the investigated composite. The optimum concentration was found to be 1.3 vol %. Affine deformation based on the Mooney-Rivilin model was used to visualize the effect of CNPs on the rubber. When polyethylene (PE) was added to rubber/CNPs at the optimum concentration (12.4 vol %), the modulus, tear resistance, and fatigue life were increased,
whereas the tensile strength decreased, and the strain at rupture MDV3100 remained almost same. A crosslink model was used to explain the influence of PE on the rubber/CNP nanocomposites. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122:3023-3029, 2011″
“PURPOSE: To compare the efficacy of conventional laser in situ keratomileusis (LASIK) in treating corneal astigmatism and in treating noncorneal ocular residual astigmatism.
SETTING: Private practice, Nashville, Tennessee, USA.
DESIGN: Retrospective case series.
METHODS: The records of dominant eyes of consecutive patients who had LASIK were retrospectively analyzed to compare the efficacy of LASIK in eyes with predominantly anterior corneal astigmatism with the efficacy in eyes with predominantly
ocular residual astigmatism (ORA). The ORA was determined by vector analysis using refractive cylinder and topographic astigmatism. Preoperatively, the ratio of ORA to preoperative refractive cylinder (R) was used to divide the patients Smoothened inhibitor into 2 groups; that is, eyes with predominantly anterior corneal astigmatism (ORA/R ratio <1.0) and eyes with predominantly ORA (ORA/R ratio >= 1.0). Efficacy was determined by examining the magnitude of the remaining uncorrected astigmatism and comparing the index of success (proportion of preoperative refractive astigmatism that remained uncorrected by LASIK) between the 2 groups.
RESULTS: The study evaluated 61 eyes of 61 patients. Conventional LASIK was twice as efficacious in the low-ORA group as in the high-ORA group. The index of success was 0.24 and 0.50, respectively, and the difference between groups was statistically significant (P = .036).
CONCLUSION: The efficacy of astigmatic correction by LASIK was significantly higher in eyes in which the preoperative refractive astigmatism was located mainly on the anterior corneal surface than in eyes in which it was mainly located posterior to the anterior corneal surface.