951 resultados para OCULAR TORSION


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We present 6 patients with ocular involvement due to paracoccidioidomycosis. All cases were confirmed by the finding of Paracoccidioides brasiliensis in histopathological or direct mycologic examination of material from the lesion in the eyelid or conjunctiva. In two cases the bulbar conjunctiva was also involved, in another the cornea, and still another patient developed endophthalmitis. The presence of this mutilating disease which may lead to blindness should be suspected when chronic blepharitis or palpebral ulcerated papular lesions are detected in patients from endemic areas of paracoccidioidomycosis. This etiology should also be suspected in patients with anterior and posterior uveitis after discarding the most frequent causes of this condition. © 1988 Kluwer Academic Publishers.

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Starting from the well established form of the Dirac action coupled to the electromagnetic and torsion field we find that there is some additional softly broken local symmetry associated with torsion. This symmetry fixes the form of divergences of the effective action after the spinor fields are integrated out. Then the requirement of renormalizability fixes the torsion field to be equivalent to some massive pseudovector and its action is fixed with accuracy to the values of coupling constant of torsion-spinor interaction, mass of the torsion and higher derivative terms. Implementing this action into the abelian sector of the Standard Model we establish the upper bounds on the torsion mass and coupling. In our study we used results of present experimental limits on four-fermion contact interaction (LEP, HERA, SLAC, SLD, CCFR) and TEVATRON limits on the cross section of new gauge boson, which could be produced as a resonance at high energy pp̄ collisions. © 1998 Elsevier Science B.V. All rights reserved.

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The methods of effective field theory are used to explore the theoretical and phenomenological aspects of the torsion field. The spinor action coupled to the electromagnetic field and torsion possesses an additional softly broken gauge symmetry. This symmetry enables one to derive the unique form of the torsion action compatible with unitarity and renormalizability. It turns out that the antisymmetric torsion field is equivalent to a massive axial vector field. The introduction of scalars leads to serious problems which are revealed after the calculation of the leading two-loop divergences. Thus the phenomenological aspects of torsion may be studied only for the fermion-torsion systems. In this part of the paper we obtain upper bounds for the torsion parameters using present experimental data on forward-backward Z-pole asymmetries, data on the experimental limits on four-fermion contact interaction (LEP, HERA, SLAC, SLD, CCFR) and also TEVATRON limits on the cross section of a new gauge boson, which could be produced as a resonance at high energy pp collisions. The present experimental data enable one to put limits on the torsion parameters for the various ranges of the torsion mass. We emphasize that for a torsion mass of the order of the Planck mass no independent theory for torsion is possible, and one must directly use string theory. © 1999 Elsevier Science B.V.

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In the framework of the teleparallel equivalent of general relativity, we study the dynamics of a gravitationally coupled electromagnetic field. It is shown that the electromagnetic field is able not only to couple to torsion, but also, through its energy-momentum tensor, produce torsion. Furthermore, it is shown that the coupling of the electromagnetic field with torsion preserves the local gauge invariance of Maxwell's theory.

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Purpose: To study the effects of two drugs (captopril and propranolol) used in the treatment of systemic hypertension, on the intraocular pressure (IOP) of anesthetized dogs. Methods: 24 dogs, divided into 3 groups of 8 each. In the first group, 1.5 mg/kg IV of captopril (an angiotensin converting enzyme inhibitor) was administered. In the second group, 1.5 mg/kg IV of propranolol (a beta-blocker) was administered. The third group was the control. IOP and blood pressure (BP) were measured by manometry. The perfusion pressure was calculated by the difference between BP and IOP (BP-IOP). The parameters were studied at 6 moments (0, 10, 30, 60, 90 and 120 minutes). Results: There was significant reduction of IOP (p<0.05) with captopril and propranolol, without difference between the drugs. With captopril the BP and PP decreased markedly at 10 and 30 minutes. With propranolol there was no reduction of BP or PP. Conclusions: Captopril and propranolol reduced IOP. However, the marked reduction of BP, and consequently of PP caused by captopril may be undesirable for irrigation of the optic nerve.

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The ocular losses are embarrassing to the bearer because they commit the face which has the essential organs for the human relationship. The present study shows the multidiscipline interaction in the treatment of a child who lost his left eye victim of a fire gun and needed an ocular plastic surgery for a correct prosthesis insertion. The ocular prosthesis fills in the ocular cavity simulating the facial growth and restoring its symmetry. Therefore, there are aesthetics, anatomic and physiological improvement on the child's face that allows her to be reinstated in society without being discriminated for her differences. © 2005 Elsevier Ltd. All rights reserved.

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The patient with anophthalmia may present feelings of inferiority and rejection. Knowing his/her needs and expectations contribute to a better technical intervention. Purpose: To elaborate a questionnaire of the psychosocial profile of the patient with anophthalmia with indication of ocular prosthesis. Methods: An exploratory research was used to elaborate the questionnaire, by means of a guided interview followed by writing down what was said by the interviewees, who were adult patients of the Bucco-Maxillo-Facial Prosthesis Center of FOSJC - UNESP. The guided interview was made up of 14 items directly related to the future outline of the profile. Each item of the interview resulted in questions of the questionnaire, which was pretested twice before reaching its final version. Results: The patients reported, in the exploratory research, unpleasant feelings with the loss of the eye; relationship shyness; expectations regarding surgery and prosthesis use; a wish to receive explanations and to hold their opinion about the treatment. The questionnaire of the psychosocial profile of the patient with anophthalmia with indication of ocular prosthesis is, therefore, made of 43 questions divided into 5 blocks in order to aid the comprehension of the inquired aspects and to facilitate both the computation of data and discussion, and also to improve the selection of questions according to the objective of the researcher or professional. Conclusions: It was concluded that the questionnaire was viable, can be used in full or by selecting blocks and provide a panorama of the patient's history related to the problem he/she faces, from the loss of the ocular globe to the confection of the prosthesis.

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Double-torsion tests were carried out on a commercial ceramic floor tile to verify whether this test is suitable for determining the R-curve of ceramics. The instantaneous crack length was obtained by means of compliance calibration, and it was found that the experimental compliance underestimates the real crack length. The load vs. displacement curves were also found to drop after maximum loading, causing the stress intensity factor to decline. The R-curves were calculated by two methods: linear elastic fracture mechanics and the energetic method. It was obtained that the average values of crack resistance, R, and the double of the work of fracture, 2 · γwof, did not depend on notch length, a0, which is a highly relevant finding, indicating that these parameters were less dependent on the test specimen's geometry. The proposal was to use small notches, which produce long stable crack propagation paths that in turn are particularly important in the case of coarse microstructures.

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A linear Lorentz connection has always two fundamental derived characteristics: curvature and torsion. The latter is assumed to vanish in general relativity. Three gravitational models involving non-vanishing torsion are examined: teleparallel gravity, Einstein-Cartan, and new general relativity. Their dependability is critically examined. Although a final answer can only be given by experience, it is argued that teleparallel gravity provides the most consistent approach.

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The purpose of this study was to assess color alteration of the paints used for iris painting in artificial eyes. Five disks of heat cured acrylic resin were confectioned by microwave energy for each paint analyzed, in a total of 40 specimens. Each specimen consisted of a colorless acrylic resin disk and another of equal size, of scleral white colored acrylic resin, with the painting interposed between the two disks. The specimens were submitted to an accelerated aging process in a chamber under ultraviolet radiation for 1,008 hours. To assess color variation, a reflective spectrophotometer was used. The results were statistically analyzed by ANOVA and the Tukey test (p < 0.05). All the paints underwent chromatic alteration. The oil paint presented the highest resistance to accelerated aging.

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In this paper we present the torsion influence in a braneworld scenario, developing the bulk metric Taylor expansion around the brane. This generalization is presented in order to better probe braneworld properties in a Riemann-Cartan framework, and it is also shown how the factors involving contorsion change the effective Einstein equation on the brane, the effective cosmological constant, and their consequence in a Taylor expansion of the bulk metric around the brane. Copyright © owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence.

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Purpose: The aim of this study was to evaluate the roughness of colorless ocular button and four brands of colorless acrylic resins designed to fabricate ocular prosthesis as a function of weathering (1008 h) and different thickness (1 and 3.5 mm). Materials and methods: One-hundred-and-twenty specimens were fabricated and distributed in 12 groups. The analysis was carried out by means of digital roughness meter. Results: Data were analyzed statistically by ANOVA and Tukey test at 1% significance. The results showed that there was no statistically significant difference after the weathering period. Both the Vipi Cril acrylic resin with 3.5 mm in thickness and ocular button with 1 mm in thickness presented the lowest roughness values (0.12. Ra). Conclusion: The roughness of the acrylic resins and the ocular button was not affect by the weathering of 1008 h. However, the thickness of the specimens proved to have a major influence on roughness property. © 2010.