Search results for "Resins"
showing 10 items of 176 documents
Visual acuity comparison of 2 models of bifocal aspheric intraocular lenses.
2008
Purpose To compare visual acuity after bilateral implantation of 2 models of multifocal aspheric intraocular lenses (IOLs). Setting Fernandez-Vega Ophthalmological Institute, Oviedo, and University of Valencia, Valencia, Spain. Methods Prospective study of patients who had bilateral implantation of an AcrySof ReSTOR SN6AD3 IOL (Group 1) or an Acri.LISA 366D IOL (Group 2). Six months postoperatively, binocular uncorrected and best corrected distance visual acuity, uncorrected-distance and best distance-corrected near visual acuity, best corrected intermediate visual acuity, and the defocus curve were measured in both IOL groups. Results Group 1 comprised 36 eyes (18 patients) and Group 2, 40…
Visual Acuity and Contrast Sensitivity in Eyes Implanted with Aspheric and Spherical Intraocular Lenses
2009
Purpose To compare visual acuity and contrast sensitivity (CS) in eyes implanted with aspheric and spherical intraocular lenses (IOLs) after cataract surgery. Design Randomized, prospective study. Participants Five hundred twenty-four eyes from 262 cataract surgery patients implanted with 2 IOL models: the AcrySof IQ (262 eyes) and AcrySof SN60AT (262 eyes; Alcon Laboratories, Fort Worth, TX). Methods High-contrast photopic best-corrected distance visual acuity (BCVA) and CS under photopic (85 cd/m 2 ) and mesopic (6 cd/m 2 ) conditions were measured. Pupil diameter was analyzed for distance vision under both lighting conditions. Follow-up was carried out for 6 months in all patients. Main …
Late postoperative opacification of MemoryLens hydrophilic acrylic intraocular lenses Case series and review
2003
Abstract Purpose: To report clinical and spectrographic analyses of 2 explanted hydrophilic acrylic intraocular lenses (IOLs). Setting: John A. Moran Eye Center, Salt Lake City, Utah, USA, and Johannes Gutenberg-University, Department of Ophthalmology, Mainz, Germany. Methods: We report 6 cases of opacification of MemoryLens ® IOLs (Ciba Vision) that occurred approximately 2 years after implantation. The anterior and posterior surfaces of the IOLs had a white, frosted appearance, and the IOLs' interior looked brown, similar to the appearance of a brunescent cataract. Two of the IOLs were explanted because of a significant decrease in visual acuity. The IOLs were sent for further clinicopath…
Refractive Lens Exchange with Foldable Toric Intraocular Lens
2009
To assess visual and refractive outcomes, and rotational stability after refractive lens exchange (RLE) with toric intraocular lens (IOL) implantation to correct ametropia and preexisting astigmatism.Prospective, nonrandomized, observational case series (self-controlled).This prospective, nonrandomized, and self-controlled study included 32 eyes of 19 consecutive patients with more than 1.00 diopter (D) of preexisting corneal astigmatism having RLE with AcrySof Toric IOL implantation (Alcon Laboratories Inc, Fort Worth, Texas, USA). Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), refractive sphere, and keratometric and refractive cylinder were recorded preoperatively …
Capsule measuring ring to predict capsular bag diameter and follow its course after foldable intraocular lens implantation
2003
Purpose: To evaluate the extent of capsular bag shrinkage after cataract surgery with intraocular lens (IOL) implantation and develop a regression formula to predict postoperative capsular bag size. Setting: Eye Hospital, Johannes Gutenberg-University, Mainz, Germany. Methods: The axial length (AL), anterior chamber depth, and corneal radius in 58 eyes were measured preoperatively. Cataract surgery was by phacoemulsification followed by implantation of a 3-piece, acrylic, posterior chamber IOL. The capsular bag diameter and anterior capsulorhexis were measured intraoperatively and 1 day and 1, 3, and 6 months postoperatively using a Koch capsule measuring ring (HumanOptics). Results: The me…
Dextran-sulfate-adsorption of atherosclerotic lipoproteins from whole blood or separated plasma for lipid-apheresis--comparison of performance charac…
2007
For many years dextran sulfate adsorption (DSA) treatment of separated plasma has been an established technology for low-density lipoprotein (LDL)-elimination. Recently a system for the treatment of whole blood based on DSA was introduced into clinical practice. To further characterize DSA treatment of whole blood, the performance characteristics of both DSA modalities were compared at two investigational sites with two alternative LDL apheresis systems being already in routine clinical use. In prospective cross-over design, DSA whole blood treatment was compared with a whole blood polyacrylate LDL adsorption system (DALI) in one study group. DSA for plasma treatment was compared with Lipid…
Analysis of bond strength between a nylon reinforcement structure and dental resins
2021
Made available in DSpace on 2021-06-25T10:30:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-05-01 Background: Nylon is a polymer that its use to reinforce dental resins has shown positive results such as increased flexural strength. The aim of this study was to evaluate the bond strength between dental resins and a nylon reinforcement. Material and Methods: Forty cylindrical nylon blocks with 13 x 23 mm with 0.5% by volume of silica and 40 without were made. Half of the samples of each nylon composition were sandblasted with aluminum oxide (50µm) for 3 s (2.8 bar pressure, distance: 20 mm, incidence angle: 90o). On the nylon blocks, cylinders of chemically activated acrylic resin…
Influence of different parameters on drug release from hydrogel systems to a biomembrane model. Evaluation by differential scanning calorimetry techn…
2000
A comparative study on the drug release capacity of four water swellable polymeric systems was carried out by differential scanning calorimetry (DSC). The polymeric systems chosen were alpha,beta-polyaspartahydrazide (PAHy) crosslinked by glutaraldehyde (GLU) (PAHy-GLU) or by ethyleneglycoldiglycidylether (EGDGE), (PAHy-EGDGE), polyvinylalcohol (PVA) crosslinked by glutaraldehyde (PVA-GLU) and alpha,beta-poly(N-hydroxyethyl)-DL-aspartamide (PHEA) by gamma irradiation (PHEA-gamma matrices). The degree of crosslinking for PAHy-GLU, PAHy-EGDGE and PVA-GLU samples was about 0.4 and 0.8. These hydrogels were characterized as free of drugs and were loaded with diflunisal (DFN) (approximately 2.5%…
Effect of media composition on long-term in vitro stability of barium alginate and polyacrylic acid multilayer microcapsules.
2000
For a number of applications stability of microcapsules is a critical factor. Since the maintenance of polyelectrolyte complexes depends considerably on the ion composition we tested the physical properties of barium alginate capsules and searched for conditions to improve stability by a multilayer coating with polyethylenimine (PEI) and polyacrylic acid (PAA). Mechanical stability and diameters were determined in barium alginate capsules and compared with multilayer capsules. Multilayer coating resulted in smaller capsules than barium complexing alone. The difference was more pronounced when CaCl2 was used instead of NaCl during coating. Barium alginate capsules and application of CaCl2 du…
Synthesis and characterisation of ordered arrays of mesoporous carbon nanofibres
2009
A facile and reproducible one-step pathway has been developed for preparing ordered arrays of mesoporous carbon nanostructures within the pores of anodized aluminium oxide (AAO) membranes, through the confined self-assembly of phenol/formaldehyde resol and amphiphilic copolymer templates. The morphology of the mesoporous carbon nanostructures can be controlled by varying the copolymer surfactant, the quantity of the resol–surfactant precursor sol used and the amount of phenol–formaldehyde resol introduced into the resol–surfactant sol. One-dimensional (1-D) carbon nanostructures, such as carbon fibres with a core–shell structure and carbon ribbons with circular mesopores running parallel to…