Visual-haptic interactions in multimodal virtual environments

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1999.Includes bibliographical references (leaves 73-75).by Wan-Chen Wu.S.M

Absorption and scattering of a high dimensional noncommutative black hole

In this work, we investigate the scattering of massless plane scalar waves by the high dimensional noncommutative Schwarzschild-Tangherlini black hole. We use the partial wave approach to determine the scattering and absorption cross sections in the incident wavelength range. Our numerical results demonstrate that the bigger the noncommutative parameter, the smaller the maximum value of the related partial absorption cross section, however the tendency is slightly. We also discovered that when the noncommutative parameter is weak, the absorption cross section of the high dimensional black hole oscillates in the low frequency zone. The total absorption cross section oscillates around the geometrical optical limit in the high frequency range, and the scattering characteristics of black holes with various parameters are visibly different. The influence on the differential scattering cross section is particularly pronounced at large angles.Comment: 10 pages and 4 figure

Oral Mucoadhesive Buccal Film of Ciprofloxacin for Periodontitis: Preparation and Characterization

Purpose: To prepare and characterise ciprofloxacin mucoadhesive buccal films for localised, improved drug delivery in periodontitis.Methods: Ciprofloxacin-loaded buccal films containing 50 mg ciprofloxacin were prepared mucoadhesive polymers sodium cellulose (SCMC) and sodium alginate, using a solvent evaporation method. The films were evaluated in terms of thickness, weight, folding endurance, surface pH, drug content, swelling, mucoadhesive properties, release characteristics, and in vivo anti-periodontitis activity, using ampicillin as the standard.Results: The buccal films showed good drug loading (94.50 ± 0.04 to 99.69 ± 0.21 %) and significant mucoadhesion in terms of in vitro residence time, as well as significant swelling (38.20 ± 1.62 to 54.42 ± 2.32 %). In addition to the good physicochemical properties of the films, ex vivo drug release was high (83.22 ± 1.42 to 90.24 ± 2.01 after 12 h. The films displayed potent anti-periodontitis activity, as indicated by a significant reduction in the bacterial count in a periodontitis model. The samples treated with BFC4 formulation (containing 3:1 SCMC and sodium alginate) exhibited the lowest growth of colonies (57 ± 2.02 CFU/mL) compared with those treated with the BFC3 formulation (69 ± 2.41 CFU/mL) and the standard (80 ± 5.22 CFU/mL).Conclusion: Formulation BFC4 has suitable physicochemical, drug release, and anti-periodontitis activity for buccal administration.Keywords: Periodontitis, Ciprofloxacin, Buccal film, Mucoadhesive, Periodontitis, Sodium carboxymethyl cellulose, Sodium alginat

Development and evaluation of miconazole mucoadhesive tablets for oropharyngeal candidiasis

Purpose: To develop mucoadhesive tablets containing miconazole (MCZ) for the treatment of oropharyngeal candidiasis, using chitosan and hydroxypropyl methylcellulose (HPMC) as mucoadhesive polymers.Methods: Mucoadhesive tablets were formulated and optimized using a 23 factorial design and direct compression method. The independent variables were compression force and concentrations of chitosan and HPMC, while mucoadhesion time and in vitro drug release were dependent variables. Tablet characterization was carried out by evaluating hardness, thickness, tablet weight variation, content uniformity, friability and in vitro drug release at salivary pH (pH 6.8).Results: The tablets showed good mucoadhesion for an extended period (8 h), and their physical characteristics were within acceptable ranges. Drug release ranged from 60.5 % to 80.8 %.Conclusion: These results indicate that the mucoadhesive MCZ tablets formulated with chitosan and HPMC possess potential for the development of therapeutic preparations for management of oropharyngeal candidiasis.Keywords: Miconazole, Oropharyngeal candidiasis, Factorial design, Mucoadhesion, Chitosan, Drug releas