No description available.

Orientador: Marisa Masumi Beppu / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-13T20:01:56Z (GMT). No. of bitstreams: 1 Weska_RaquelFarias_M.pdf: 2528542 bytes, checksum: c7faca11cd121664f82f4719ad8f66fd (MD5) Previous issue date: 2009 / Resumo: A fibroína de seda tem sido amplamente explorada para aplicações biomédicas, devido à sua biocompatibilidade, biodegradabilidade e mínima reação inframatória. A esterilização é uma etapa fundamental no processamento de biomateriais, e não deve alterar de forma negativa as propriedades funcionais dos dispositivos médicos. Estudos recentes verificaram que a fibroína pode ser utilizada como suporte para mimetizar a biomineralização, promovendo o crescimento de cristais de hidroxiapatita. O objetivo deste trabalho foi analisar a influência de diferentes métodos de esterilização nas características físicas, mecânicas e biológicas de membranas densas e porosas de fibroína de seda, e também estudar a possibilidade de aplicação de membranas de fibroína como biomaterial, pelo estudo da calcificação in vitro. Membranas densas e porosas de fibroína foram esterilizadas por radiação ultravioleta, etanol 70%, autoclave, óxido de etileno e radiação gama, e foram analisadas por MEV, FTIR-ATR, DRX, testes mecânicos e de citotoxicidade indireta. Para os ensaios de calcificação in vitro, as membranas de fibroína foram imersas em SBF por sete dias, e caracterizadas por MEV e EDX. Os resultados de esterilização mostraram que nenhum método ocasionou degradação das membranas ou a formação de produtos citotóxicos. Os métodos que utilizaram solvente orgânico, e aumento de umidade e/ou temperatura (etanol 70%, autoclave e óxido de etileno) tornaram as membranas densas mais cristalinas, e as membranas porosas mais estáveis, o que pode ser aproveitado quando se deseja que as membranas apresentem uma degradação in vivo mais lenta, dependendo da aplicação. Os resultados obtidos de calcificação in vitro indicaram que a fibroína pode induzir a calcificação, pela formação de depósitos de fosfato de cálcio com relações de Ca/P similares à da hidroxiapatita e seus precursores. A membrana porosa apresentou maior tendência à calcificação, quando comparada com a membrana densa, devido à sua rugosidade e porosidade, podendo desta forma ser considerada para aplicação em regeneração óssea. / Abstract: Silk fibroin has been widely explored for many biomedical applications, due to its biocompatibility, biodegradability and minimal inflammatory reactions. Sterilization is a fundamental step in biomaterials processing, and it must not alter in a negative way the functionality of medical devices. On the applicability of fibroin as a biomaterial, recent studies verified that fibroin can be used as a scaffold for mimicking biomineralization, promoting the growing of hydroxyapatite crystals. The aim of this study was to analyze the influence of different sterilization methods on physical, mechanical and biological characteristics of dense and porous silk fibroin membranes, and also to study the application of the fibroin membranes as biomaterials, through in vitro calcification studies. Dense and porous fibroin membranes were sterilized by ultraviolet radiation, 70% ethanol, autoclave, ethylene oxide and gamma radiation, and were analyzed by SEM, FTIR-ATR, XRD, mechanical and cytotoxicity tests. For in vitro calcification experiments, the fibroin membranes were soaked in SBF for seven days, and characterized by SEM and EDS. The results for sterilization indicated that none of the methods caused degradation or formation of cytotoxic substances. The methods that used organic solvent, and increase of humidity and/or temperature (70% ethanol, autoclave and ethylene oxide) increased the crystallinity of the dense membranes, and stabilized the porous membranes, characteristics that may be utilized when a slow in vivo degradation is desired, depending on the application. The calcification experiments indicated that silk fibroin may induce calcification, by forming calcium phosphate deposits with a Ca/P ratio similar to that of hydroxyapatite and its precursors. Porous membranes presented higher tendency to calcify, when compared to dense membranes, due to its surface roughness and high porosity, indicating that porous silk fibroin membranes may be considered for application in bone regeneration. / Mestrado / Engenharia de Processos / Mestre em Engenharia Química

Most eye drops are dispensed in multi-dose containers, hence protection should be given against microbial contamination during use. To remain sterile during it's use, the solution should contain a preservative in such concentration so that it kills micro-organisms in a short time. It has been stated in the literature that the instillation of contaminated eye drops constitutes a greater danger than the intravenous injection of a contaminated solution since the cornea is nonvascular and lacks the normal antimicrobial defences of the blood stream. Amongst the preservatives used, those included in the official formulations for eye drops are Chlorhexidine Acetate, Phenyl Mercuric Nitrate, Benzalkonium Chloride, and to some extent Phenylethanol, which may be used in combination with Benzalkonium Chloride. The main purpose of this investigation has been to determine the adsorption of these preservatives by different filters during sterilization by filtration. Part 1, p. 2.

Boston University. University Professors Program Senior theses. / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / 2031-01-02

Indiana University-Purdue University Indianapolis (IUPUI) / This study involved two areas of investigation. First, questionairres were sent to 350 orthodontists in order to determine the types and frequency of methods used to treat contaminated instruments in their practices. Two hundred eighty replies were received. Second, using orthotolidine reagent strips, three commonly-used cleaning methods (alcohol wipe, soap and water scrub, and ultrasonic cleaning) were compared as to their effectiveness in the removal of a potentially dangerous contaminant, blood, from a representative orthodontic instrument, the band pusher. A sample of 15 instruments was tested. The survey showed that a variety of cleaning, disinfecting, and sterilizing procedures were used in various combinations in the practices surveyed. Less than 4.3% of the respondants treated hand instruments -- the group most likely to be contaminated with blood -- in a manner acceptable to various authorities on the subject, such as: The Expert Committee on Hepatitis of the World Health Organization, the United States Institutes of Health, and The Council on Dental Therapeutics of the American Dental Association. Of the three cleaning methods tested, ultrasonic cleaning was the most effective for removing blood from the test instruments, and alcohol wiping was least effective. Both alcohol wiping and soap and water scrubbing left detectable amounts of blood on all instruments tested. Since: a) orthodontic instruments may be contaminated with blood during routine treatment procedures, b) asymptomatic carriers of serum hepatitis may constitute at least 1% of the population, and the viruses of both forms of viral hepatitis may be found in the serum of 5 - 35% of apparently healthy persons, c) as little as .00005 ml of infected blood is capable of transmitting the disease, and d) a high percentage of the sample of orthodontists responding used inadequate methods to treat their instruments, the danger of transmission of viral hepatitis exists in the great majority of orthodontic practices surveyed in this study.

No description available.

Graduation date: 1991

Thesis (M.S.)--University of Michigan, 1984.

Thesis (M.S.)--University of Michigan, 1984.

In 1997 the journalist and author Maciej Zaremba published an article in the Swedish newspaper Dagens Nyheter. The article drew associations between racial biology, eugenics and the Swedish social democratic governance. Zaremba’s article presented records from a period of forty years when over 60 000 people of the Swedish population were sterilized. The records showed that many of them were executed under questionable circumstances. Zaremba woke a debate within the Swedish mass media with the intended goal to foil the general view of the Swedish state of welfare. In this study the debate that led to the laws of sterilization will be investigated to provide answers if the motives behind the law were based on eugenic motives. Furthermore, any disagreements between the different parties in the parliament are analyzed. Previous published research in the field evolves around the origin and the consequences of the Swedish sterilization laws however, the analysis of the argumentation that led to the creation of the regulations seems to be missing. The empirical data is gathered through qualitative research of parliament protocols and newspapers followed by an analysis based on Foucaults concept of bio power. The model for a power analysis by Axelsson and Qvarsebos have been used to concretize the concept of bio power. The analysis shows that the arguments were often rooted in eugenic thoughts and beliefs. The overall purpose was to improve the human race through the fabrication of sterilizations.