997 resultados para Eyes, Artificial


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Objective: To investigate the efficacy of a novel ocular lubricant compared with a commercially marketed ocular lubricant in a group of noncontact lens wearers currently using over-the-counter products for the management of symptoms of moderate to severe dry eye.

Methods: This was a prospective, double-masked study that randomized 110 subjects in a ratio of 1:1 to receive a novel ocular lubricant (test group) or a marketed ocular lubricant (control group). Subjects were instructed to instill the lubricant eye drops at least three times daily. After enrollment, subjects were evaluated at baseline and at 7 and 30 days. They were also required to complete a series of home-based subjective questionnaires after 15 days. Main outcomes were subjective symptoms and objective clinical assessment at 7 and 30 days.

Results: The test group had higher overall comfort ratings than the control group (P = 0.012). Seventy-one percent of the test group and 57% of the control group said the drops used “somewhat” or “definitely” improved ocular comfort; 62% of the test group had greater end-of-day comfort compared with 45% of the control group (P = 0.015). There were no between-group differences in visual acuity, tear quality or quantity, corneal staining, conjunctival staining, or bulbar and limbal conjunctival hyperemia.

Conclusions: The novel ocular lubricant offers equivalent or superior comfort compared with a marketed lubricant eye drop. Objective clinical outcomes were not statistically significantly different between the two groups.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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"September 1985."

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Prosthetic eyes are artificial substitutes for the eyeball, made of heat-curing acrylic resin, serving to improve the esthetic appearance of the mutilated patient and his/her inclusion in society. The aim of this study was to assess the flexural strength of two heat-curing acrylic resins used for manufacturing prosthetic eyes. Thirty-six specimens measuring 64 x 10 x 3.3 mm were obtained and divided into four groups: acrylic resin for artificial sclera N1 (Artigos Odontológicos Clássico, São Paulo, SP, Brazil), heat-cure water technique (GI) and microwave-cured (GII); colorless acrylic resin for prosthetic eyes (Artigos Odontológicos Clássico, São Paulo, SP, Brazil), heat-cure water technique (GIII) and microwave-cured (GIV). Mechanical tests using three point loads were performed in a test machine (EMIC, São José dos Pinhais, PR, Brazil). The analysis of variance and the Tukey test were used to identify significant differences (p < 0.01). Groups GII and GIV presented, respectively, the highest (98.70 ± 11.90 MPa) and lowest means (71.07 ± 8.93 MPa), with a statistically significant difference. The cure method used for the prosthetic eye resins did not interfere in their flexural strength. It was concluded that all the resins assessed presented sufficient flexural strength values to be recommended for the manufacture of prosthetic eyes.

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Esthetics and durability of materials used to fabricate artificial eyes has been an important issue since artificial eyes are essential to restore esthetics and function, protect the remaining tissues and help with patients' psychological therapy. However, these materials are submitted to degrading effects of environmental agents on the physical properties of the acrylic resin. OBJECTIVE: This study assessed the color stability of acrylic resins used to fabricate sclera in three basic shades (N1, N2 and N3) when subjected to accelerated aging, mechanical and chemical polishing. MATERIAL AND METHODS: Specimens of each resin were fabricated and submitted to mechanical and chemical polishing. Chromatic analysis was performed before and after accelerated aging through ultraviolet reflection spectrophotometry. RESULTS: All specimens revealed color alteration following polishing and accelerated aging. The resins presented statistically significant chromatic alteration (p<0.01) between the periods of 252 and 1008 h. CONCLUSIONS: Both polishing methods presented no significant difference between the values of color derivatives of resins.

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The aim of this study was to evaluate the opacity of the polymethylmethacrylate for ocular prosthesis using an ocular button, a colorless resin for the ocular prostheses, and 4 brands of acrylic colorless resin in the function of weathering (0, 504, or 1008 h) and thickness (1 and 3.5 mm). One hundred twenty specimens were confectioned (made) and allocated into 12 groups (n = 10). Opacity analysis was carried out with a spectrophotometer of visible ultraviolet reflection before and after weathering by 504 and 1008 hours. Data for the opacity were expressed in ΔE. Data were then analyzed statistically by analysis of variance and the Tukey test (P < 0.01). The data demonstrated statistically significant differences; manufactured ocular button (ΔE = 47.4) and the resin Vipi Cril (ΔE = 38.11) presented greater and minor values of opacity, respectively. The weathering showed statistical difference among times (0 h, ΔE = 36.32; 504 h, ΔE = 39.98; and 1008 h, ΔE = 43.9). Ocular button and evaluated resins presented greater values of opacity when presented in 3.5 mm in thickness. The values of opacity increased with the progression of the time of weathering, independent of the evaluated material and the thickness.

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The experiments were designed to evaluate the biocompatibility of a plastically compressed collagen scaffold (PCCS). The ultrastructure of the PCCS was observed via scanning electron microscopy. Twenty New Zealand white rabbits were randomly divided into experimental and control groups that received corneal pocket transplantation with PCCS and an amniotic membrane, respectively. And the contralateral eye of the implanted rabbit served as the normal group. On the 1st, 7th, 14th, 21st, 30th, 60th, 90th, and 120th postoperative day, the eyes were observed via a slit lamp. On the 120th postoperative day, the rabbit eyes were enucleated to examine the tissue compatibility of the implanted stroma. The PCCS was white and translucent. The scanning electron microscopy results showed that fibers within the PCCS were densely packed and evenly arranged. No edema, inflammation, or neovascularization was observed on ocular surface under a slit lamp and few lymphocytes were observed in the stroma of rabbit cornea after histological study. In conclusion, the PCCS has extremely high biocompatibility and is a promising corneal scaffold for an artificial cornea. (c) 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.

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Human eyes have a remarkable ability to recognize hundreds of colour shades, which has stimulated the use of colorants, especially for clothing, but toxicological studies have shown that some textile dyes can be hazardous to human health. Under conditions of intense perspiration, dyes can migrate from coloured clothes and penetrate into human skin. Garments made from cotton fabrics are the most common clothing in tropical countries, due to their high temperatures. Aiming to identify safe textile dyes for dyeing cotton fabrics, the genotoxicity [in vitro Comet assay with normal human dermal fibroblasts (NHDF), Tail Intensity] and mutagenicity [Salmonella/microsome preincubation assay (30 min), tester strains TA98, TA100, YG1041 and YG1042] of Reactive Blue 2 (RB2, CAS No. 12236-82-7, C.I. 61211) and Reactive Green 19 (RG19, CAS No. 61931-49-5, C.I. 205075) were evaluated both in the formulated form and as extracted from cotton fibres using different artificial sweats. Both the dyes could migrate from cotton fibres to sweat solutions, the sweat composition and pH being important factors during this extraction. However, the dye sweat solutions showed no genotoxic/mutagenic effects, whereas a weak mutagenic potential was detected by the Ames test for both dyes in their formulated form. These findings emphasize the relevance of textile dyes assessment under conditions that more closely resemble human exposure, in order to recognize any hazard. © 2013 Elsevier Ltd. All rights reserved.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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This article describes the development of a visual stimulus generator to be used in neuroscience experiments with invertebrates such as flies. The experiment consists in the visualization of a fixed image that is displaced horizontally according to the stimulus data. The system is capable of displaying 640 x 480 pixels with 256 intensity levels at 200 frames per second (FPS) on conventional raster monitors. To double the possible horizontal positioning possibilities from 640 to 1280, a novel technique is presented introducing artificial inter-pixel steps. The implementation consists in using two video frame buffers containing each a distinct view of the desired image pattern. This implementation generates a visual effect capable of doubling the horizontal positioning capabilities of the visual stimulus generator allowing more precise and movements more contiguous. (C) 2011 Elsevier Inc. All rights reserved.

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Both of the engraved titles have had the imprint erased, only the date 1817 being left intact.