Publications by authors named "Roberta Ribeiro de Almeida"

We report on the synthesis and characterization of bent-core liquid crystal (LC) compounds and the preparation of mixtures that provide an optically isotropic antiferroelectric (OI-AFLC) liquid crystal display mode over a very wide temperature interval and well below room temperature. From the collection of compounds synthesized during this study, we recognized that several ternary mixtures displayed a modulated SmCP phase down to below -40 °C and up to about 100 °C on both heating and cooling, as well as optical tilt angles in the transformed state of approximately 45° (optically isotropic state). The materials were fully characterized and their liquid crystal as well as electro-optical properties analyzed by polarized optical microscopy, differential scanning calorimetry, synchrotron X-ray diffraction, dielectric spectroscopy, and electro-optical tests.

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Objective: Investigate the effect of acupuncture on brain perfusion using ethyl cysteinate dimer single-photon emission computed tomography ((99m)Tc-ECD SPECT) in patients with tinnitus.

Methods: This randomized, single-blind, sham-control study examined patients (18-60 years old) with normal hearing and chronic, idiopathic, continuous tinnitus. Fifty-seven subjects were randomly assigned to true (n = 30) or sham (n = 27) acupuncture (ACP); (99m)Tc-ECD SPECT examinations were performed before and after 12 twice-weekly ACP sessions.

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Unlabelled: Tinnitus is characterized by the perception of sound in the absence of an external auditory stimulus. The network connectivity of auditory and non-auditory brain structures associated with emotion, memory and attention are functionally altered in debilitating tinnitus. Current studies suggest that tinnitus results from neuroplastic changes in the frontal and limbic temporal regions.

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Conclusion: The patients with unilateral chronic vestibular hypofunction detected by caloric test demonstrated at least some sort of altered vestibular evoked myogenic potential (VEMP) in 63.63% of the cases. The VEMP altered side was the same as the unilateral vestibular hypofunction side in 54.

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Fat implantation in the vocal fold is described as a method of repairing vocal fold histostructural lesions that correlate with mucosal wave abnormalities. The aim of this study was to evaluate the histologic behavior of autologous fat implants. A fat block was implanted in pockets surgically created in the vocal folds of rabbits, and the inflammatory process induced was compared to the status of the contralateral vocal fold.

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