990 resultados para Nasal Cavity
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Atomic ions trapped in micro-fabricated surface traps can be utilized as a physical platform with which to build a quantum computer. They possess many of the desirable qualities of such a device, including high fidelity state preparation and readout, universal logic gates, long coherence times, and can be readily entangled with each other through photonic interconnects. The use of optical cavities integrated with trapped ion qubits as a photonic interface presents the possibility for order of magnitude improvements in performance in several key areas of their use in quantum computation. The first part of this thesis describes the design and fabrication of a novel surface trap for integration with an optical cavity. The trap is custom made on a highly reflective mirror surface and includes the capability of moving the ion trap location along all three trap axes with nanometer scale precision. The second part of this thesis demonstrates the suitability of small micro-cavities formed from laser ablated fused silica substrates with radii of curvature in the 300-500 micron range for use with the mirror trap as part of an integrated ion trap cavity system. Quantum computing applications for such a system include dramatic improvements in the photonic entanglement rate up to 10 kHz, the qubit measurement time down to 1 microsecond, and the measurement error rates down to the 10e-5 range. The final part of this thesis details a performance simulator for exploring the physical resource requirements and performance demands to scale such a quantum computer to sizes capable of performing quantum algorithms beyond the limits of classical computation.
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A low-threshold nanolaser with all three dimensions at the subwavelength scale is proposed and investigated. The nanolaser is constructed based on an asymmetric hybrid plasmonic F-P cavity with Ag-coated end facets. Lasing characteristics are calculated using finite element method at the wavelength of 1550 nm. The results show that owing to the low modal loss, large modal confinement factor of the asymmetric plasmonic cavity structure, in conjunction with the high reflectivity of the Ag reflectors, a minimum threshold gain of 240 cm−1 is predicted. Furthermore, the Purcell factor as large as 2518 is obtained with optimized structure parameters to enhance rates of spontaneous and stimulated emission.
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Sub-ice shelf circulation and freezing/melting rates in ocean general circulation models depend critically on an accurate and consistent representation of cavity geometry. Existing global or pan-Antarctic data sets have turned out to contain various inconsistencies and inaccuracies. The goal of this work is to compile independent regional fields into a global data set. We use the S-2004 global 1-minute bathymetry as the backbone and add an improved version of the BEDMAP topography for an area that roughly coincides with the Antarctic continental shelf. Locations of the merging line have been carefully adjusted in order to get the best out of each data set. High-resolution gridded data for upper and lower ice surface topography and cavity geometry of the Amery, Fimbul, Filchner-Ronne, Larsen C and George VI Ice Shelves, and for Pine Island Glacier have been carefully merged into the ambient ice and ocean topographies. Multibeam survey data for bathymetry in the former Larsen B cavity and the southeastern Bellingshausen Sea have been obtained from the data centers of Alfred Wegener Institute (AWI), British Antarctic Survey (BAS) and Lamont-Doherty Earth Observatory (LDEO), gridded, and again carefully merged into the existing bathymetry map. The global 1-minute dataset (RTopo-1 Version 1.0.5) has been split into two netCDF files. The first contains digital maps for global bedrock topography, ice bottom topography, and surface elevation. The second contains the auxiliary maps for data sources and the surface type mask. A regional subset that covers all variables for the region south of 50 deg S is also available in netCDF format. Datasets for the locations of grounding and coast lines are provided in ASCII format.
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Light confinement and controlling an optical field has numerous applications in the field of telecommunications for optical signals processing. When the wavelength of the electromagnetic field is on the order of the period of a photonic microstructure, the field undergoes reflection, refraction, and coherent scattering. This produces photonic bandgaps, forbidden frequency regions or spectral stop bands where light cannot exist. Dielectric perturbations that break the perfect periodicity of these structures produce what is analogous to an impurity state in the bandgap of a semiconductor. The defect modes that exist at discrete frequencies within the photonic bandgap are spatially localized about the cavity-defects in the photonic crystal. In this thesis the properties of two tight-binding approximations (TBAs) are investigated in one-dimensional and two-dimensional coupled-cavity photonic crystal structures We require an efficient and simple approach that ensures the continuity of the electromagnetic field across dielectric interfaces in complex structures. In this thesis we develop \textrm{E} -- and \textrm{D} --TBAs to calculate the modes in finite 1D and 2D two-defect coupled-cavity photonic crystal structures. In the \textrm{E} -- and \textrm{D} --TBAs we expand the coupled-cavity \overrightarrow{E} --modes in terms of the individual \overrightarrow{E} -- and \overrightarrow{D} --modes, respectively. We investigate the dependence of the defect modes, their frequencies and quality factors on the relative placement of the defects in the photonic crystal structures. We then elucidate the differences between the two TBA formulations, and describe the conditions under which these formulations may be more robust when encountering a dielectric perturbation. Our 1D analysis showed that the 1D modes were sensitive to the structure geometry. The antisymmetric \textrm{D} mode amplitudes show that the \textrm{D} --TBA did not capture the correct (tangential \overrightarrow{E} --field) boundary conditions. However, the \textrm{D} --TBA did not yield significantly poorer results compared to the \textrm{E} --TBA. Our 2D analysis reveals that the \textrm{E} -- and \textrm{D} --TBAs produced nearly identical mode profiles for every structure. Plots of the relative difference between the \textrm{E} and \textrm{D} mode amplitudes show that the \textrm{D} --TBA did capture the correct (normal \overrightarrow{E} --field) boundary conditions. We found that the 2D TBA CC mode calculations were 125-150 times faster than an FDTD calculation for the same two-defect PCS. Notwithstanding this efficiency, the appropriateness of either TBA was found to depend on the geometry of the structure and the mode(s), i.e. whether or not the mode has a large normal or tangential component.
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There are two features of /æ/ in British Columbia (BC) English that are widely attested in the literature: it is undergoing retraction and lowering and it is sensitive to the influence of certain following consonants. The present study aims to utilize both features to evaluate the phonological status of /æ/ before nasal consonants in BC English by examining the progression of sound change and the phonemic organization of /æ/ in different environments. Specifically, production and perception results are taken together to evaluate the phonetic position of pre-nasal /æ/ relative to other environments. These results are interpreted within a modular feedforward architecture of phonology to establish the phonological (allophonic) and phonetic (shallowphonic) rules that govern the internal relationships between the subphonemic elements of /æ/ in BC English. Further, the findings of this study provide evidence for the allophone being the target of sound change, rather than the phoneme.
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Different types of network oscillations occur in different behavioral, cognitive, or vigilance states. The rodent hippocampus expresses prominentoscillations atfrequencies between 4 and 12Hz,which are superimposed by phase-coupledoscillations (30 –100Hz).These patterns entrain multineuronal activity over large distances and have been implicated in sensory information processing and memory formation. Here we report a new type of oscillation at near- frequencies (2– 4 Hz) in the hippocampus of urethane-anesthetized mice. The rhythm is highly coherent with nasal respiration and with rhythmic field potentials in the olfactory bulb: hence, we called it hippocampal respiration-induced oscillations. Despite the similarity in frequency range, several features distinguish this pattern from locally generatedoscillations: hippocampal respiration-induced oscillations have a unique laminar amplitude profile, are resistant to atropine, couple differentlytooscillations, and are abolished when nasal airflow is bypassed bytracheotomy. Hippocampal neurons are entrained by both the respiration-induced rhythm and concurrent oscillations, suggesting a direct interaction between endogenous activity in the hippocampus and nasal respiratory inputs. Our results demonstrate that nasal respiration strongly modulates hippocampal network activity in mice, providing a long-range synchronizing signal between olfactory and hippocampal networks.
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Thesis (Master's)--University of Washington, 2016-08
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Introdução: A respiração nasal é a única considerada fisiológica para o ser humano, e proporciona o normal crescimento e desenvolvimento do complexo craniofacial. Qualquer alteração no mecanismo funcional poderá alterar o equilíbrio e conduzir a desvios da normalidade e a consequentes deformidades. Além de afetar as estruturas craniofaciais, a respiração bucal poderá afetar também as estruturas dentárias. Objetivo: Determinar a influência da respiração oral nas alterações oro-faciais, por meio de uma revisão da literatura publicada sobre o tema. Materiais e métodos: Foi realizado um levantamento bibliográfico de dados utilizando motores de busca eletrónicos, livros científicos e teses de mestrado. Os artigos foram selecionados segundo o seu nível de evidência científica. Resultados: A respiração oral é uma síndrome comum nas crianças em idade escolar, que se encontram em fase de crescimento e de desenvolvimento dos padrões craniofaciais. As possíveis alterações da função respiratória podem dar origem a modificações dentárias e faciais nestes pacientes. Conclusões: O diagnóstico precoce da respiração oral é de extrema importância, uma vez que pode influenciar o correto desenvolvimento da cavidade oral e do complexo craniofacial. Quando detetada deve-se procurar realizar uma avaliação das vias aéreas e dos possíveis hábitos orais do paciente. Em seguida é efetuada uma intervenção adequada e eficaz com o intuito de minimizar as consequências decorrentes da respiração oral.
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O seio maxilar é o seio paranasal mais susceptível a invasões bacterianas, tanto pelo óstio nasal, como pela cavidade oral. As sinusites maxilares têm como causas mais frequentes, as infecções víricas, rinites alérgicas ou não alérgicas, variações anatómicas, diabetes mellitus, fumar, nadar, mergulhar, escalar a altas atitudes, e as infecções e tratamentos dentários. A pesquisa bibliográfica, foi realizada sem quaisquer limitações temporais, com restrição linguística a Português, Espanhol e Inglês, sendo excluídos os artigos de outros idiomas; em vários livros e revistas, assim como artigos científicos obtidos, entre Maio e Julho de 2015, nos motores de busca Pubmed, ScienceDirect, Scielo, Elsevier e B-on. A sinusite maxilar odontogénica é uma doença infecto-inflamatória, habitualmente associada à ruptura da membrana de Schneider e a processos infecciosos dentários crónicos. Causa hiperplasia e hipertrofia da mucosa, o que origina sinais e sintomas próprios, assim como mudanças radiográficas perceptíveis. Existem diferentes etiologias de causa odontogénica: cárie, doença periodontal, quistos odontogénicos e iatrogenia – tratamento endodôntico não cirúrgico, cirurgia endodôntica, comunicações oro-antrais, implantes dentários, elevação do seio maxilar, cirurgia pré-protética e cirurgia ortognática – sendo que a iatrogenia é a mais comum (cerca de 56%). Esta patologia afecta com mais frequência indivíduos dos 42,7 aos 51, 7 anos, e preferencialmente a região molar, seguida dos pré-molares e em alguns casos, caninos. Os organismos que dominam na fase aguda e crónica, são sensivelmente os mesmos, mas em número diferente, e existe uma conexão entre a flora comensal periapical e a flora patogénica em caso de sinusite maxilar odontogénica. O diagnóstico é essencialmente clínico, no entanto existem diferentes exames complementares para confirmarem ou formarem o diagnóstico. Pela grande acessibilidade ao método radiográfico, torna-se fundamental que o médico dentista saiba diferencial as diversas patologias que afectam o seio maxilar. O tratamento abrange a eliminação da causa dentária e o tratamento farmacológico, da infecção, essencialmente à base de antibióticos, e da dor se esta existir. E o tratamento cirúrgico, que contempla a punção-lavagem sinusal, antrostomia intranasal, técnica de Caldwell-Luc e cirurgia sinusal endoscópica. Concluindo, o médico dentista deve ter um amplo conhecimento sobre esta patologia para que a possa reconhecer, tratar ou preveni-la.
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Objectivo: analisar os resultados da experiência de um hospital distrital na realização de dacriocistorrinostomias (DCR) endoscópicas e determinar o papel actual desta técnica para tratamento de obstruções da via nasolacrimal. Materiais e Métodos: Reviram-se os processos clínicos de 67 dacriocistorrinostomias endoscópicas consecutivas realizadas no Hospital Fernando Fonseca entre Janeiro de 1997 e Dezembro de 2012. Analisou-se a clínica apresentada pelos doentes, o nível da estenose detectado na dacriocistografia, as complicações intra e pós-operatórias e os resultados funcionais e anatómicos pós-operatórios. Resultados: Dos 51 doentes, 12 eram do sexo masculino e 34 do sexo feminino, com média de idades de 57 anos. A epífora foi a queixa predominante. Com a excepção de dois casos, todas as cirurgias foram executadas com instrumentos de dissecção motorizados. O sucesso da DCR endoscópica foi de 78,1%. Conclusões: A DCR endoscópica é uma técnica simples, segura e eficaz para o tratamento das obstruções distais da via nasolacrimal.
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The permanent contact with cork may lead to constant exposure to fungi, raising awareness as a potential occupational hazard in the cork industry.The presence of fungi belonging to the Penicillium glabrum complex has been associated with the development of respiratory diseases such as suberosis, one of the most prevalent diseases among workers from cork industries, besides occupational asthma. Azoles are used as pesticides but also the first line therapy in the treatment of Aspergillus infections; azole-resistance as been described as to have also an environmental source and is considered an emerging public health problem.The aim of this work was to characterize fungal distribution and to evaluate the presence of azole-resistant Aspergillus isolates in nose swab samples from the cork industry workers.
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Different types of network oscillations occur in different behavioral, cognitive, or vigilance states. The rodent hippocampus expresses prominentoscillations atfrequencies between 4 and 12Hz,which are superimposed by phase-coupledoscillations (30 –100Hz).These patterns entrain multineuronal activity over large distances and have been implicated in sensory information processing and memory formation. Here we report a new type of oscillation at near- frequencies (2– 4 Hz) in the hippocampus of urethane-anesthetized mice. The rhythm is highly coherent with nasal respiration and with rhythmic field potentials in the olfactory bulb: hence, we called it hippocampal respiration-induced oscillations. Despite the similarity in frequency range, several features distinguish this pattern from locally generatedoscillations: hippocampal respiration-induced oscillations have a unique laminar amplitude profile, are resistant to atropine, couple differentlytooscillations, and are abolished when nasal airflow is bypassed bytracheotomy. Hippocampal neurons are entrained by both the respiration-induced rhythm and concurrent oscillations, suggesting a direct interaction between endogenous activity in the hippocampus and nasal respiratory inputs. Our results demonstrate that nasal respiration strongly modulates hippocampal network activity in mice, providing a long-range synchronizing signal between olfactory and hippocampal networks.
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Introduction: Formaldehyde is a compound with a wide range and is commonly used in anatomy and pathology laboratories. At room temperature is quickly volatilized to a pungent and suffocating gas and its inhalation has been correlated to nuclear alterations in different tissues. We aimed to investigate whether exposure to this compound was correlated with the appearance of cytotoxic and genotoxic features in the nasal epithelial cells of students enrolled in a human anatomy course. Material and Methods: This prospective study collected periodically nasal cells from mucosa of 17 volunteers from two different undergraduate programs with different workloads of practical lessons in an anatomy laboratory, 30 and 90 hours per semester. Cells were staining according to Feulgen method and nuclear morphology was analyzed to detect possible damage. Dunn's post hoc test was used in the statistical analysis. Pearson's correlation was performed for gender, age and questionnaire responses. Results: Epithelial cells showed indicators of cytotoxicity and mutagenicity. Students with a more extensive workload in anatomy laboratory displayed a more severe profile with an increase in karyorrhexis (p < 0.05) over time. The micronucleus analysis showed difference between first and second collection (p < 0.01), although it was not maintained over the time. Students with a less extensive workload display no differences in most of cytological features. Despite karyorrhexis was present in a greater number of cells, for this group no significant difference was observed between any range. The same was observed to karyolysis and micronucleus (p > 0.05). Conclusion: Individuals exposed for short periods of time to formaldehyde are subject to the toxic action of this gas. Karyorrhexis was the most frequently observed cytotoxic feature and micronucleus showed an increase between the first time point. The patterns observed between the student's groups suggest a negative effect due to exposure time.
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Durante su ciclo de vida las tortugas marinas están expuestas a muchos peligros, cada año mueren al ser capturadas accidentalmente en las redes de pesca, víctimas de la pérdida de hábitat de áreas de alimentación y anidación, debido al desarrollo costero e incremento del turismo, lo anterior ha ocasionado que se les considere como especies en peligro o amenazadas de extinción. La mayoría de las enfermedades de las tortugas marinas aún no han sido descritas; por lo que es necesario conocer las bacterias que se encuentran presente en el organismo y los posibles vectores de enfermedades. El objetivo del presente estudio fue determinar la composición de la flora bacteriana en el área nasal y cloacal de las tortugas marinas Lepidochelys olivacea durante su época de anidación entre los meses de junio a octubre del año 2012, se colectaron muestras bacteriológicas provenientes de 20 hembras anidantes mediante recorridos nocturnos en tres playas El Faro, El Cocal y Salinitas pertenecientes al Área Natural Protegida Complejos Los Cóbanos Departamento de Sonsonate, El Salvador. Las muestras se colectaron a través del uso de hisopos estériles que se introdujeron en la cloaca durante el desove y en uno de los conductos nasales. Estas fueron trasladadas en al laboratorio de Biología de la Universidad de El Salvador en menos de 24 horas para su posterior análisis. En el laboratorio las muestras nasales fueron cultivadas en agar sangre, MacConkey y agar manitol sal, las cloacales fueron cultivadas en agar sangre, MacConkey, TCBS y XLD, a todas las colonias aisladas se les realizaron pruebas bioquímicas rutinarias IMVIC. Además se utilizó API 20E.