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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.
231

Avaliação da técnica de obturação usando cone único de sistemas reciprocantes com diferentes cimentos, em relação ao selamento apical e adesividade à dentina / Evaluation of single-cone obturation techniques of reciprocating systems with different sealers related to the apical sealing and bond strength to dentin

Carla Cristina Camilo Araujo 18 September 2014 (has links)
O objetivo deste estudo ex vivo foi avaliar o selamento apical e a resistência de união à dentina radicular da obturação de canais radiculares usando a técnica do cone único dos sistemas WaveOne e Reciproc com diferentes cimentos, em comparação à técnica da condensação lateral. Foram selecionados caninos superiores humanos cujas coroas foram removidas permanecendo as raízes com 15 mm. A amostra foi distribuída aleatoriamente de acordo com o sistema de instrumentação/ técnica de obturação: Reciproc R40/Cone único R40; WaveOne Large/Cone único Large e ProTaper Universal (até instrumento F4)/Condensação lateral. Posteriormente, 9 subgrupos (n=20) foram estruturados conforme o cimento endodôntico: AH Plus, Epiphany SE e MTA Fillapex. Após preparo biomecânico e obturação dos canais radiculares, os espécimes foram armazenados a 37&deg;C e 100% de umidade por período correspondente a três vezes o tempo de endurecimento dos cimentos. O método de filtração de fluidos foi utilizado para verificação do selamento apical em 10 espécimes de cada subgrupo. Espécimes apenas com cone de guta-percha e sem cimento (n=6) e outros completamente impermeabilizados (n=2) foram os controles positivos e negativos, respectivamente. Dos 10 espécimes remanescentes de cada subgrupo foram obtidas fatias de dentina com 1 mm de espessura (3 por terço radicular: cervical, médio e apical), sendo 6 (2 fatias por terço) utilizadas para o teste de push-out. O tipo de falhas ocorridas após a desunião foi avaliado em microscópio óptico (25X de aumento). Dentre as outras fatias, foram selecionadas 5 de cada terço, em cada subgrupo, para análise por microscopia eletrônica de varredura (MEV) (1000X de aumento). Foram mensurados doze pontos na interface material obturador/dentina e os seguintes escores foram atribuídos para a adaptação da obturação: 0 (seções sem lacunas); 1 (seções com pequenas falhas, <1 &mu;m); 2 (seções com muitas lacunas, entre 1 &mu;m e 10 &mu;m) e 3 (sem adaptação, lacunas >10 &mu;m). Os dados de infiltração apical e resistência de união (RU) foram analisados pelo teste ANOVA duas vias e teste de Tukey (p<0,05). Os testes de Kruskal-Wallis e Student-Newman-Keuls (p<0,05) foram utilizados para análise dos dados referentes à adaptação da obturação. Em relação ao selamento apical, as três técnicas apresentaram diferenças entre si, com melhores resultados para a condensação lateral (p<0,05). A técnica WaveOne propiciou menor índice de filtração de fluido que a Reciproc, sem diferença estatisticamente significante entre os cimentos (p>0,05). As técnicas de cone único apresentaram menores valores de RU que a condensação lateral (p<0,05), enquanto nesta última técnica o cimento AH Plus apresentou os maiores valores de RU, sendo estatisticamente superior ao MTA Fillapex e Epiphany SE (p<0,05). Houve predominância de falhas adesivas à dentina no terço apical e mistas nos terços médio e cervical. A análise por MEV mostrou melhor adaptação na interface dentina/material obturador para o cimento AH Plus que para os cimentos MTA Fillapex e Epiphany SE (p<0,05). Concluiu-se que as técnicas de cone único apresentaram maior infiltração apical e menor resistência de união que a condensação lateral. Melhor adaptação marginal foi obtida com o cimento AH Plus, independentemente da técnica de obturação utilizada. / The aim of this ex vivo study was to evaluate the apical sealing and bond strength (BS) of root canal filling using single-cone from WaveOne and Reciproc systems associated to different sealers compared with the lateral condensation technique. The crowns of maxillary human canines were sectioned in order to standardize the root length to 15 mm. The sample was randomly allocated according to instrumentation system /obturation technique: R40 Reciproc file/ R40 single cone; WaveOne Large/Large single cone; ProTaper Universal (up to F4 file)/ Lateral condensation. Subsequently, 9 subgroups (n=20) were defined according to root canal sealer: AH Plus, Epiphany SE and MTA Fillapex. After the preparation and filling procedures, the specimens were stored at 37°C and 100% humidity for a period three times longer than the setting time of the sealers. The fluid filtration method was used to investigate the apical sealing in 10 specimens of each subgroup. Specimens with only cone and without sealer (n=6) and others completely sealed (n=2) were used as positive and negative controls, respectively. Slices with 1 mm thickness (3 per root third: cervical, middle and apical) were obtained from the remaining specimens of each subgroup, while 6 slices (2 per third) were submitted to push-out test. Failures modes were evaluated in optical microscope (magnification 25X). Among the other slices for each experimental condition, five were selected from each third for analysis by scanning electron microscopy (SEM) (magnification 1000X). Twelve points were measured in filling material/dentin interface, and the following scores were used in order to evaluate the root filling adaptation: 0 (sections without gaps); 1 (sections with small gaps, <1&mu;m); 2 (sections with many gaps, between 1 &mu;m and 10 &mu;m) and 3 (without adaptation, gaps>10 &mu;m). The data on apical infiltration and BS were analyzed by two way ANOVA test and Tukey&prime;s test (p<0.05). The Kruskal-Wallis test followed by Student-Newman-Keuls test (p<0.05) were used for data analysis concerning the adaptation of the root filling. Regarding the apical sealing, there was statistical difference between the obturation techniques, whereas the lateral condensation showed the best results (p<0.05). The WaveOne technique provided lower rate of fluid filtration than Reciproc, and no statistically significant differences were observed between the sealers (p>0.05). The single-cone techniques showed lower values of BS than lateral condensation, in which AH Plus showed the highest BS values, with statistical difference from MTA Fillapex and Epiphany SE (p<0.05). There was predominance of adhesive failures in the apical third and mixed failures in the middle and cervical thirds. The SEM analysis revealed better adaptation in the filling material/dentin interface for AH Plus than MTA Fillapex and Epiphany SE. It was concluded that the single-cone techniques resulted in highest apical infiltration and lowest BS than lateral condensation one. Better marginal adaptation was obtained with AH Plus, regardless of obturation technique used.
232

Avaliação da tomografia computadorizada Cone Beam como método de proservação de lesões periapicais após o tratamento endodôntico em pacientes com fissura labiopalatina / Evaluation of cone beam computed tomography as a method of follow-up of periapical lesions after endodontic treatment in patient with cleft lip and palate

Tulio Lorenzo Olano Dextre 29 June 2012 (has links)
O objetivo deste trabalho foi comparar a eficácia da Tomografia Computadorizada Cone Beam e a Radiografia Periapical como métodos de proservação de lesões periapicais após o tratamento endodôntico. Foram avaliadas no estudo Radiografias e Tomografias de 1.462 indivíduos com fissura labiopalatina no Hospital de Reabilitação de Anomalias Craniofaciais Universidade de São Paulo, que compareceram para o tratamento endodôntico entre os anos 2009 e 2011. De acordo com os critérios de inclusão, foram selecionados 46 dentes unirradiculares com lesão periapical, os quais foram divididos nos grupos: avaliação Radiográfica (Grupo I) e avaliação Tomográfica (Grupo II). Os dados foram analisados por meio do escore PAI para as alterações periapicais encontradas. Nos resultados observou-se que houve diferença estatisticamente significativa nos grupos estudados. Em 34 casos os escores atribuídos às Tomografias dos dentes avaliados foram maiores do que os escores atribuídos às Radiografias Periapicais dos mesmos dentes avaliados, comprovando a maior precisão da Tomografia Computadorizada Cone Beam. Desta forma, a análise dos resultados obtidos neste trabalho permite constatar que a Tomografia Computadorizada Cone Beam é mais eficaz na proservação de lesões periapicais do que a Radiografia Periapical após o tratamento endodôntico em pacientes com fissura labiopalatina. / The aim of this study was to compare the effectiveness of Cone Beam Computed Tomography and periapical radiography as a follow-up method of periapical lesions after endodontic treatment. We evaluated in the study radiographs and tomography scans of 1,462 individuals with cleft lip and palate at the Hospital of Rehabilitation of Craniofacial Anomalies - University of Sao Paulo who came for treatment endodontic between the years 2009 and 2011. According to inclusion criteria were selected 46 single-rooted teeth with periapical lesions, which were divided into groups radiographic evaluation (Group I) and tomographic evaluation (Group II). Data were analyzed using the PAI score for periapical changes found. The results were observed that statistically significant differences in the groups studied. In 34 cases the CT scores attributed to the teeth evaluated were higher than the scores attributed to the radiographs of same teeth evaluated, demonstrating the greater precision of Cone Beam Computed Tomography. Thus, analysis of results obtained in this work demonstrates that the Cone Beam Computed Tomography is more effective in follow-up of periapical lesions than periapical radiography after endodontic treatment in patients with cleft lip and palate.
233

Estudo comparativo entre a tomografia volumétrica Cone Beam e radiografias periapicais no auxílio ao diagnóstico endodôntico / Comparative study between Cone-Beam volumetric tomography and periapical radiographs on helping endodontic diagnosis

D’Addazio, Paulo Sérgio dos Santos 30 January 2009 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-10-07T19:23:21Z No. of bitstreams: 1 paulosergiodossantosdaddazio.pdf: 1362518 bytes, checksum: 07214ba3207394666338f0eeb8fcbd4e (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-10-11T15:49:18Z (GMT) No. of bitstreams: 1 paulosergiodossantosdaddazio.pdf: 1362518 bytes, checksum: 07214ba3207394666338f0eeb8fcbd4e (MD5) / Made available in DSpace on 2016-10-11T15:49:18Z (GMT). No. of bitstreams: 1 paulosergiodossantosdaddazio.pdf: 1362518 bytes, checksum: 07214ba3207394666338f0eeb8fcbd4e (MD5) Previous issue date: 2009-01-30 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este estudo objetivou analisar comparativamente a tomografia volumétrica Cone-Beam e o exame radiográfico periapical, pela técnica de Clark, quanto à identificação de acidentes e complicações endodônticas, simuladas, de interesse endodôntico. Dezesseis dentes humanos, em três mandíbulas humanas, foram submetidos ao preparo de 20 alterações/lesões, de modo a simular situações que podem constituir-se em complicações para o diagnóstico e tratamento endodôntico. As simulações foram divididas em quatro grupos: G1) fragmento de lima fraturada no conduto radicular; G2) perfurações/rasgos no conduto radicular; G3) núcleos metálicos com desvio em relação ao trajeto do canal radicular e; G4) reabsorções externas. Cada dente foi submetido a exame radiográfico periapical pela técnica de Clark e cada mandíbula, a exame por Tomografia Computadorizada Cone-Beam. A análise dos exames foi realizada por um único observador, especialista em radiologia odontológica. Os resultados gerais utilizando-se o teste estatístico de McNemar demonstraram diferença estatisticamente significante (p < 0,05) para a Tomografia Computadorizada Cone-Beam em relação às radiografias periapicais. A análise estatística dos resultados individuais por alteração/lesão, utilizando-se o teste estatístico de Wilcoxon, demonstrou que houve superioridade da Tomografia Computadorizada Cone-Beam na identificação de reabsorções, com valor estatisticamente significante (p < 0,05). De acordo com os resultados pode-se concluir que, de uma forma geral, a Tomografia Computadorizada Cone-Beam apresentou superioridade em relação às radiografias periapicais convencionais, na identificação das alterações/lesões simuladas. / This study aimed to analyze and compare volumetric tomography ConeBeam and periapical examination, by technique of Clark, identifying accidents and endodontic complications, which were simulated, for endodontic interest. Sixteen human teeth from three human jaws were submitted to preparation of 20 changes/injuries in order to simulate situations that can lead to complications for diagnosis and endodontic treatment. The simulations were divided into four groups: G1) fragment of fractured file in radicular duct; G2) holes/slots in radicular duct; G3) metal cores with deviation from the path of root canal and, G4) external resorption. Each tooth was submitted to examination of periapical radiography, by technique of Clark and each jaw, by the examination of Cone-Beam Computed Tomography. The analysis of the tests was performed by a single observer, a specialist in dental radiology. The overall results using McNemar statistical test showed a difference statistically significant (p < 0.05) for Cone-Beam Computed Tomography if compared to periapical radiographs. Statistical analysis of individual results for alteration/defect, using Wilcoxon statistical test showed superiority of Cone-Beam Computed Tomography to identify resorptions, with statistically significant value (p < 0.05). According to the results it can be concluded that, generally, the Cone-Beam Computed Tomography showed superiority in relation to conventional periapical radiographs, identifying simulated changes/injuries.
234

Usefulness of dental cone beam computed tomography (CBCT) for detetion of the anatomical landmarks of the external, middle and inner ear

Taleb Mehr, Mahdieh 01 May 2013 (has links)
Thesis problem: Cone beam computed tomography (CBCT) can provide images with identical information and considerable dose reduction compared with reasonably low costs compared to multislice computed tomography (MSCT) especially where multiple follow up imaging studies are needed. The purpose of this study was to evaluate the diagnostic usefulness of CBCT, using i-CAT®'s software, for detection of the anatomical landmarks of the external, middle and inner ear to answer this question whether MSCT Can be replaced by dental CBCT for evaluation of the temporal bone. Material and methods: Cone beam computed tomography (CBCT) images of 63 subjects made with the same machine, with unknown clinical histories and no evidence of pathosis on CBCT images, were evaluated by two oral and maxillofacial radiologists retrospectively. Seven anatomical points (scutum, oval window, incudomalleolar joint, the tympanic/horizontal and mastoid/vertical segments of the facial nerve, anterior and posterior crura of stapes) of the right and left temporal bone (total of 120 temporal bones) were evaluated. The results were provided as percentage of the points identified by each radiologist. The intra and inter observer agreement were calculated using kappa statistic. Results: The scutum, the tympanic/horizontal segment of the facial nerve canal and the oval window of the right and left temporal bone of 63 cases (total 126 temporal bones) were visualized by the first observer as well-defined structures in 100%, 96.03% and 100% of the cases, respectively. The tympanic/horizontal segment of the facial nerve canal was visualized as a poorly-defined structure in 2.38 % and could not be identified in 1.59% of the cases. The anterior and posterior crura of stapes, the mastoid/vertical segments of the facial nerve canal and the incudomalleolar joint were visualized as well-defined structures in 24.60%, 53.17%, 99.21% and 57.94% of the cases, as poorly defined structures in 32.54%, 41.27%, 0.79% and 39.68% of the cases respectively. The anterior and posterior crura of stapes, the mastoid/vertical segments of the facial nerve canal and the incudomalleolar joint could not be identified in 42.86%, 5.56%, 0% and 2.38% of the cases respectively. The intra- and inter-observer agreement ranged from strong for tympanic/horizontal and mastoid/vertical segments of the facial nerve canal to poor for the anterior and posterior crura of stapes and also the incudomalleolar joint. Conclusion: The i-CAT CBCT machine is a promising replacement for MSCT in evaluation of the temporal bone where there is no need for evaluation of the anterior and posterior crura of stapes and the incudomalleolar joint which are the smallest anatomical structures in the temporal bone. Other CBCT machines with higher contrast to noise ratio should be evaluated for detection of those anatomical structures since CBCT can reduce the patient dose substantially where multiple follow up CT studied are needed. Key words: Computed tomography; cone beam CT; multislice helical CT; middle ear; inner ear; temporal bone.
235

Voxel Cone Tracing / Voxel Cone Tracing

Pracuch, Michal January 2016 (has links)
This thesis deals with the global illumination in the scene by using Voxel Cone Tracing method. It is based on the voxelization of a triangle mesh scene. The voxels can be stored to a full regular 3D grid (texture) or to the hierarchic Sparse Voxel Octree for saving of the memory space. This voxel representation is further used for computations of the global indirect illumination in real time within normal triangle mesh scenes for more realistic final image. Values from the voxels are obtained by tracing cones from the pixels which we want to get illumination for.
236

An Investigation of the Cone and Seed Insects of Whitebark Pine and Alpine Larch Emphasizing the Western Conifer Seed Bug (Hemiptera: Coreidae) and the Larch Cone Fly (Diptera: Anthomyiidae)

Anderton, Laurel K. 01 May 2000 (has links)
Laboratory and field feeding tests with Leptoglossus occidentalis Heidemann proved that both immature and mature seed bugs can use cones and foliage of whitebark pine, Pinus albicaulis Engelmann, as a food source for 1- to 2-week periods. Damage to unprotected whitebark pine cones by seed bugs ranged from 0.3 to 2.1 % of seeds per cone, and for bagged cones averaged 0.7% of seeds per cone. Total insect damage ranged from 0.4 to 7.2% of seeds per cone. A seed chalcid, Megastigmus sp., was documented for the first time on whitebark pine and damaged 4.7% of examined seeds at one site. Four out of five upper elevation subsites had an average of 24.9% fewer filled seeds per cone than lower elevation subsites. Within-site elevation differences had no significant effect on cone length, number of seeds per cone, percentage of potential seeds per cone, or percentages of seed bug and insect-damaged seeds per cone. The larch cone fly Strobilomyia macalpinei Michelsen was found in cones of alpine larch, Larix lyallii Parl., in the Bitterroot Range of Montana. This is the first record of this species in the United States and the first since its description in 1988. Ninety-four percent of a sample of alpine larch cones were damaged by cone fly larvae, and 64% contained larvae or puparia. Colored traps did not succeed in trapping adult cone flies in an alpine larch stand with no cone crop.
237

Sufficient conditions for local exactness of the exact penalty function method in nonsmooth optimization

Al hashimi, Farah 01 May 2019 (has links)
No description available.
238

Rhythmic Relations

Gray, Jessica M. 28 October 2010 (has links)
No description available.
239

Inclusions différentielles d'évolution associées à des ensembles sous-lisses / Evolution differential inclusions associated with subsmooth sets

Noel, Jimmy 23 May 2013 (has links)
Cette thèse est consacrée à l'étude d'existence de solutions pour certains problèmes d'évolution. Il s'agit de processus de rafle perturbés associés d'une part à des ensembles prox-réguliers et d'autre part à des ensembles sous-lisses. Les ensembles sont supposés évoluer de façon lipschitzienne ou absolument continue. / This dissertation is devoted to the study of the existence of solutions for some evolution problems. The study is concerned with perturbed sweeping processes associated on the one hand with prox-regular sets and the other hand with subsmooth sets. It is assumed that the sets move either in a Lipschitz way or in an absolutely continuous way.
240

Maké sopky na Marsu: obrazová analýza, numerické modelování a srovnání s pozemskými analogy / Small-scale volcanoes on Mars: image analysis, numerical modeling and comparison with terrestrial analogs

Brož, Petr January 2015 (has links)
Small-scale volcanoes represent diverse group of landforms which vary in morphology, morphometry, and mechanisms of their formation. They are the most common volcanic form on Earth, and their existence and basic characteristics were also predicted for Mars. Availability of high-resolution image data now allows to search, identify and interpret such small volcanic features on the martian surface. This thesis extends our knowledge about the small-scale volcanoes with the following objectives: (a) to document the existence of martian analogues to some of the terrestrial volcanoes, in particular scoria cones, tuff cones, tuff rings and lava domes; (b) to establish their morphological and morphometrical parameters; and (c) to examine the effect of environmental factors, which differ on Earth and Mars, on the mechanisms of formation of the scoria cones. Interpretation of remote sensing images and digital elevation models reveals that scoria cones, tuff rings and cones, and lava domes exist on different parts of the martian surface and, in some cases, far away from previously well-known volcanic provinces. Scoria cones have been identified in the volcanic field Ulysses Colles situated within the Tharsis volcanic province; tuff cones and tuff rings have been found in the Nephenthes/Amenthes region at the...

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