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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Simulation of Fluid Dynamics and Particle Transport in a Realistic Human Nasal Cavity

Inthavong, Kiao, kiao.inthavong@rmit.edu.au January 2008 (has links)
Airflow and particle transport through the nasal cavity was studied using Computational Fluid Dynamics (CFD). A computational model of the human nasal cavity was reconstructed through CT scans. The process involved defining the airway outline through points in space that had to be fitted with a closed surface. The airflow was first simulated and detailed airflow structures such as local vortices, wall shear stresses, pressure drop and flow distribution were obtained. In terms of heat transfer the differences in the width of the airway especially in the frontal regions was found to be critical as the temperature difference was greatest and therefore heating of the air is expedited when the air is surrounded by the hotter walls. Understanding the effects of the airway geometry on the airflow patterns allows better predictions of particle transport through the airway. Inhalation of foreign particles is filtered by the nasal cilia to some degree as a defence mechanism of the airway. Particles such as asbestos fibres, pollen and diesel fumes can be considered as toxic and lead to health problems. These particles were introduced and the effects of particle morphology were considered by customising the particle trajectory equation. This mainly included the effects of the drag correlation and its shape factor. Local particle deposition sites, detailed deposition efficiencies and particle trajectories were obtained. High inertial particles tended to be filtered within the anterior regions of the cavity due to a change in direction of the airway as the air flow changes from vertical at the inlet to horizontal within the main nasal passage. Inhaled particles with pharmacological agents are often deliberately introduced into the nasal airway with a target delivery. The mucous lined airway that is highly vascular provides an avenue for drug delivery into the blood stream. An initial nasal spray experiment was performed to determine the parameters that were important for nasal spray drug delivery. The important parameters were determined to be the spray angle, initial particle velocity and particle swirl. It was found that particles were formed at a break-up length at a cone diameter greater than the spray nozzle diameter. The swirl fraction determined how much of the velocity magnitude went into a tangential component. By combining a swirling component along with a narrow spray into the main streamlines, greater penetration of larger particles into the nasal cavity may be possible. These parameters were then used as the boundary conditions for a parametric study into sprayed particle drug delivery within the CFD domain. The results were aimed to assist in the design of more efficient nasal sprays.
92

Nasal mucosal reactivity after long-time exposure to building dampness /

Rudblad, Stig, January 2004 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 5 uppsatser.
93

Clinical, immunological and olfactory aspects of sinusitis and nasal polyposis : with special reference to patients with cystic fibrosis /

Henriksson, Gert, January 2004 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 4 uppsatser.
94

Interactions between oral and nasal microorganisms and the bioactive glass S53P4 with special reference to nasal cavity surgery

Stoor, Patricia. January 2001 (has links)
Thesis--University of Turku, Finland, 2001. / Added t.p. with thesis statement inserted. Includes bibliographical references.
95

Use of conventional tomography to evaluate changes in the nasal cavity with rapid palatal expansion

Palaisa, Jacqueline, January 2005 (has links)
Thesis (M.S.)--West Virginia University, 2005 / Title from document title page. Document formatted into pages; contains vii, 57 p. Vita. Includes abstract. Includes bibliographical references (p. 46-52).
96

Interactions between oral and nasal microorganisms and the bioactive glass S53P4 with special reference to nasal cavity surgery

Stoor, Patricia. January 2001 (has links)
Thesis--University of Turku, Finland, 2001. / Added t.p. with thesis statement inserted. Includes bibliographical references.
97

Incidental sinonasal findings in cone-beam computed tomography imaging of the temporomandibular joints prevalence and clinical significance /

Guedes, Inês Helena. January 2010 (has links)
Thesis (M.Sc.)--University of Alberta, 2010. / A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Medical Sciences, Temporomandibular Disorders/Orofacial Pain. Title from pdf file main screen (viewed on April 23, 2010). Includes bibliographical references.
98

Detecção dos genes de virulência e identificação do perfil clonal de isolados de Staphylococcus aureus colonizantes de nasofaringe obtidos em estudo de base populacional /

Abraão, Lígia Maria. January 2013 (has links)
Orientador: Maria de Lourdes Ribeiro de Souza da Cunha / Coorientador: Carlos Magno Castleo Branco Fortaleza / Banca: Carlos Roberto Veiga Kiffer / Banca: Elizabeth Losshchagin Pizzolitto / Resumo: Estudos recentes apontam para elevação da incidência e da gravidade das infecções por Staphylococcus aureus. Esse fato é agravado pela ampla disseminação de isolados de Staphylococcus aureus resistentes à meticilina (MRSA) nos hospitais, além de sua recente introdução na comunidade. A colonização nasal de indivíduos assintomáticos é o principal fator responsável pela persistência e disseminação de S. aureus nas populações humanas. Assim sendo, inquéritos de carreamento nasal são importantes para estimar a "carga" (burden) de S. aureus como um todo e de MRSA na comunidade. Além disso, a compreensão da relação bactéria-hospedeiro e dos fatores de virulência envolvidos se faz necessária para o combate às infecções que colocam em risco a vida da população em geral. O presente trabalho teve como objetivo investigar a distribuição de clones de Staphylococcus aureus e MRSA na população da área urbana de Botucatu, SP, identificando a prevalência dos determinantes de virulência junto aos fatores de risco associados em isolados obtidos da nasofaringe de indivíduos hígidos do município. Um total de 223 amostras de S. aureus isoladas de secreções nasais foi submetido a testes de susceptibilidade antimicrobiana à oxacilina e cefoxitina através da técnica de discodifusão. O método de E-test foi empregado para determinar a Concentração Inibitória Miníma (CIM) em amostras resistentes. Em seguida, foram realizadas reações de PCR para a detecção dos genes mecA, genes codificadores de fatores de virulência das enterotoxinas (sea, seb e sec) e toxina associada à síndrome do choque tóxico (tst); toxinas esfoliativas A e B (eta, etb), leucocidina de Panton-Valentine (lukS-PV e lukF-PV), hemolisinas alfa e delta (hla e hld); e biofilme (icaA e icaD). A tipagem molecular para a determinação dos clusters foi realizada pela técnica de PFGE. Para avaliar os fatores ... / Abstract: Recent findings show an increase on the incidence and severity of Staphylococcus aureus infection. This fact is worsened by the wide dissemination of the methicillin-resistant S. aureus (MRSA) isolates in hospitals and its recent introduction in the community settings. The nasal colonization in asymptomatic individuals remains the main factor responsible for the persistence and dissemination of S. aureus in the human population. Thereby, nasal carriage surveys are an important tool in order to estimate the total S. aureus burden and the MRSA in the community. Besides, understanding the bacterial-host relationship and the virulence factors involved is necessary in order to manage the infections that jeopardize the population's health. The present study aims at investigating the clonal distribution of S. aureus and MRSA strains in an urban population area in Botucatu, SP, identifying both the prevalence of the virulence determinants together to the associated risk factors in samples obtained from the nasopharynx of healthy individuals from Botucatu. A total of 223 S. aureus samples isolated from nasal secretions were submitted to the antimicrobial susceptibility tests through the disk-difusion method with oxacillin and cefoxitin disks. The E-test method with oxacillin was applied in order to obtain the Minimum Inhibitory Concentration (MIC) among oxacillin disk resistant samples. Afterwards, PCR (Polimerase Chain Reaction) was carried out for the detection of the mecA gene and of the following virulence genes: enterotoxins (sea, seb and sec), toxic shock syndrome toxin (tst), exfoliative toxin A and B (eta, etb), Panton-Valentine Leukocidin (lukS-PV and lukF-PV), alphaand delta-hemolysins (hla and hld), and biofilms (icaA and icaD). The PFGE molecular typing was employed in order to determine the prevalent clusters. The univariate and multivariate linear regression was carried out so that the risk factors ... / Mestre
99

Avaliação da rdiografia cefalométrica lateral como meio de diagnóstico da hipertrofia de adenóide

Barbosa, Marcelo de Castellucci e January 2005 (has links)
Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2013-04-23T18:45:15Z No. of bitstreams: 1 Dissertação marcelo-sec.pdf: 542785 bytes, checksum: a79f804abd3185cbf4a93f637e7b233a (MD5) / Approved for entry into archive by Rodrigo Meirelles(rodrigomei@ufba.br) on 2013-05-08T11:40:42Z (GMT) No. of bitstreams: 1 Dissertação marcelo-sec.pdf: 542785 bytes, checksum: a79f804abd3185cbf4a93f637e7b233a (MD5) / Made available in DSpace on 2013-05-08T11:40:42Z (GMT). No. of bitstreams: 1 Dissertação marcelo-sec.pdf: 542785 bytes, checksum: a79f804abd3185cbf4a93f637e7b233a (MD5) Previous issue date: 2005 / A hipertrofia de adenóide promove uma diminuição do espaço livre da nasofaringe e se constitui em uma das principais causas da respiração bucal. Entre os métodos utilizados para o diagnóstico desta condição, os mais precisos são a endoscopia nasal e a ressonância magnética, por permitirem a visualização da nasofaringe em três dimensões. No entanto, o método mais utilizado, em Odontologia, é a radiografia cefalométrica lateral. Torna-se, portanto, de grande importância, a verificação da eficiência deste método de diagnóstico. Este trabalho foi realizado com o objetivo de determinar a eficácia da radiografia cefalométrica lateral no diagnóstico da hipertrofia de adenóide, pela comparação deste método com a endoscopia nasal. Foram avaliados 30 indivíduos (7 a 12 anos) sem história prévia de cirurgia otorrinolaringológica. Todos fizeram um exame de endoscopia nasal e uma radiografia cefalométrica lateral. Nas endoscopias, foi registrada a porcentagem de obstrução da nasofaringe, e nas radiografias, a menor dimensão ântero-posterior livre da nasofaringe. Os valores encontrados pelos dois exames se mostraram fortemente correlacionados (r = ? 0,793, p-valor < 0,01). Em seguida, foram realizados os testes de validade e confiabilidade para o diagnóstico radiográfico. Para isso, foram considerados portadores de hipertrofia severa de adenóide, os pacientes que apresentaram, na endoscopia, obstrução da nasofaringe igual ou superior a 75% e, nas radiografias, o menor diâmetro antero-posterior da nasofaringe igual ou inferior a 5 mm. O exame radiográfico teve uma sensibilidade de 75%, especificidade de 86,3%, valor preditivo positivo de 66,7%, valor preditivo negativo de 90,4% e a exatidão foi de 83,3%. A radiografia cefalométrica lateral, então, se mostrou um exame eficiente para o diagnóstico da hipertrofia de adenóide, o que foi comprovado pela forte correlação entre os seus resultados e os da endoscopia nasal, que é considerado o exame padrão-ouro para o diagnóstico desta condição. / Salvador
100

Teste da medida da diferença de potencial nasal transepitelial

Procianoy, Elenara da Fonseca Andrade January 2014 (has links)
O teste da diferença de potencial nasal (DPN) é um exame que mede a diferença bioelétrica através do epitélio nasal, a qual resulta do transporte iônico transepitelial dos íons sódio (Na+), pelo canal ENaC (Epitelial Na+ Channel), e cloro (Cl-), pelo canal CFTR(Cystic Fibrosis Transmembrane Conductance Regulator). DPN tem sido utilizada como teste de auxilio diagnóstico em doenças associadas à disfunção do CFTR, como a Fibrose Cística (FC). FC é uma doença genética autossômica recessiva causada por mutações que afetam o funcionamento do canal CFTR (e secundariamente do ENaC) e levam a manifestações em diversos órgãos. Normalmente a dosagem de cloro no suor acima de 60 mEq/L ou a identificação de mutações nos dois alelos confirmam diagnóstico de FC. Porém, existem casos atípicos com exames considerados inconclusivos onde as características eletrofisiológicas decorrentes da disfunção do CFTR devem ser demonstradas para estabelecimento do diagnóstico. A identificação correta destes casos é importante para instituição do tratamento adequado e definição do prognóstico. O objetivo principal deste trabalho foi padronizar a técnica da DPN para sua futura aplicação como ferramenta diagnóstica através da determinação dos seus valores de referência, de sensibilidade, de especificidade e de concordância entre os resultados das duas narinas. Secundariamente, objetivamos analisar as relações entre a presença de função residual do CFTRe a concentração de cloro no suor, fenótipo pancreático, presença de Pseudomonas aeruginosa, função pulmonar e genótipo na amostra de pacientes comFC. Foi realizado um estudo transversal com realização da DPN em um grupo de pacientes com FC (n=29, idade:15±6 anos) e dois grupos controle: não=FC (n=19, idade: 15 ± 10 anos) e sadios (n=19, idade: 17 ± 8 anos). Os resultados demonstraram que os valores da DPN são significativamente diferentes no grupo FC (FC: DPNmax: -34 ± 9mV, Δamil: -20 ± 9mV, ΔCl: 4 ± 5mV, Δamilo-iso: -19 ± 9 mV e indiceDPN: 0.85 ± 0.23; não-FC:DPNmax: -14 ± 5mV, Δamil: -6 ± 3mV, ΔCl: 17 ± 9mV, Δamilo-iso: -1 ± 4 mV e indiceDPN: 0.11 ± 0.11) e sadios: DPNmax: -15 ± 4mV, Δamil: -6 ± 3mV, ΔCl: 11 ± 7mV, Δamilo-iso: -2 ± 4 mV e indiceDPN: 0.20±0.14),com sensibilidade e especificidade de 95-96% e concordância de resultado entre as duas narinas maior para a DPNmax (r=0,934). A função residual da CFTR não mostrou relação com nenhum dos parâmetros fenotípicos avaliados. Somente mostrou relação com a gravidade do genótipo. Entretanto, foi observada relação entre os parâmetros que avaliam a hiperfunção do ENaC existente na FC e o fenótipo. Concluímos com este trabalho que foi possível reproduzir e padronizar esta técnica da DPN e demonstrar que o fenótipo da FC está mais relacionado à alteração do transporte do íon sódio através do ENaC do que à presença de função residual da CFTR. / Nasal potential difference test (NPD) is a test that measures the bioelectrical difference across the nasal epithelium, which results from transepithelial ion transport of sodium (Na+), by ENaC channels (Epitelial Na+ Channel) and chloride (Cl-), by CFTR (Cystic Fibrosis Transmembrane Conductance Regulator).NPD has been used as a diagnostic tool in CFTR related disorders, such as Cystic Fibrosis (CF). CF is an autosomal recessive genetic disease caused by mutations that affect the function of the CFTR channel (andsecondarily of the EnaC)and lead to manifestations in various organs. Normally sweat chloride concentration > 60 mEq / L and identification of two CFTR mutations confirm the CF diagnosis. However there are atypical cases with inconclusive sweat chloride or genetic where the electrophysiological characteristics induced by CFTR dysfunction has to be demonstrated for diagnosis. The correct identification of these cases is important for institution of appropriate treatment and definition of prognosis. The objective of this study was to standardize the NPD for its future application as a diagnostic tool through the determination of reference values, sensibility and specificity and agreement of the results between both examined nostrils. Secondarily, we analyzed the relations between residual CFTR function and sweat chloride concentration, pancreatic phenotype, Pseudomonas aeruginosa positivity, pulmonary function and genotype in the sample of CF patients. It was a transversal study where the NPD was measured in a group of CF patients (n = 29, age: 15 ± 6 years) and two control groups: non-CF (n = 19, age: 15 ± 10 years) and healthy (n = 19, age: 17 ± 8 years). The results showed that NPD was significantly different in CF (NPDmax: -34 ± 9mV, Δamil: -20 ± 9mV, ΔCl: 4 ± 5mV, Δamilo-iso: -19 ± 9 mV e NPDindex: 0.85 ± 0.23; non-CF: NPDmax: -14 ± 5mV, Δamil: -6 ± 3mV, ΔCl: 17 ± 9mV, Δamilo-iso: -1 ± 4 mV and NPDindex: 0.11 ± 0.11) and healthy: NPDmax: -15 ± 4mV, Δamil: -6 ± 3mV, ΔCl: 11 ± 7mV, Δamilo-iso: -2 ± 4 mV and NPDindex: 0.20±0.14) with sensibility and specificity of 95-96% and agreement between both nostrils greater for NPDmax (r=0.934). The residual CFTR function did not show relation with all phenotypic parameters evaluated. It just showed relation with genotype severity. Indeed it was observed a relation between the parameters that assess the ENaC hyperfunction that occurs in CF and the phenotype. We concluded with this study that was possible to reproduce and to standardize the NPD and to demonstrate that the phenotype is more related to sodium transport alterations through ENaC than to the presence of residual CFTR function.

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