The fundamental process is thermal in nature, leading to phase decomposition, phase changes, and mass transport in the center of the irradiated region, as well as the formation of lead-or barium-rich debris zones. Crystallization is also a consequence of the exposure to the laser light. We further report on preirradiation experiments in which low-power exposure above a determined energy threshold results
in structural changes that bridge the gap between the amorphous state and the ultimate crystalline arrangement. Finally, we discuss the application of the laser irradiation in the making of vanadate microspheres. (C) Cyclopamine concentration 2011 American Institute of Physics. [doi:10.1063/1.3517081]“
“Blends of polystyrene/poly (4-vinylpyridine) have been prepared by casting from a common solvent. The compatibility of the blends was studied by using dilute solution viscometry (DSV), differential scanning calorimetery (DSC), Fourier transformation-infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). The relative viscosity versus composition plots for the blends are not perfect linear. The corresponding intrinsic viscosity values show negative
deviation from ideal behavior when plotted against composition. Also, the modified Krigbaum and Wall interaction parameter, Delta b, shows small and negative values for all compositions except for the blend PS/P4VP (25 : 75). The results indicate that the polymers are incompatible but small interaction values predict physically miscible blends which
eventually Citarinostat research buy show phase separation, as is observed in the present studies. However, the blends as obtained show a single, composition-dependent, glass transition temperature that fits the Fox equation well, indicating the presence of homogeneous phase. The constant, k obtained from Gordon-Taylor equation suggests intermolecular attraction between these polymers. FT-IR and SEM support the results of DSV and DSC. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 120: 1729-1735, 2011″
“PURPOSE: To compare visual outcomes and changes in total higher-order aberrations https://www.selleckchem.com/products/ly2606368.html (HOAs) between conventional photorefractive keratectomy (PRK) and custom PRK
SETTING: Department of Ophthalmology, Labbafinejad Medical Center, Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences and Negah Eye Center, Tehran, Iran.
METHODS: This clinical trial comprised eyes having bilateral myopic PRK with the Technolas 217z excimer machine One eye had conventional ablation (conventional group) and the other eye, wavefront-guided custom treatment (custom group) Changes in postoperative visual acuity, cycloplegic refraction, contrast sensitivity function, and root mean square higher-order aberrations (RMS HOAs) were compared between the 2 groups
RESULTS: The mean age of the 28 patients (56 eyes) was 26 7 years.