2,648 research outputs found

    Secondary Endothelial Keratoplasty—A Narrative Review of the Outcomes of Secondary Corneal Endothelial Allografts

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    Background: We review the literature on the efficacy and safety outcomes of secondary Descemet stripping endothelial keratoplasty (DSEK) and Descemet membrane endothelial keratoplasty (DMEK). Methods: Literature search of English-written publications up to September 27, 2020 in PubMed database, using the terms "endothelial keratoplasty" in combination with keywords "secondary" or "repeat." In addition, we manually searched the references of the primary articles. Results: Twenty-seven studies (n = 651 eyes) were retained and reviewed, including 10 studies on repeat DSEK, 8 studies on repeat DMEK, 6 studies of DMEK following DSEK, and 3 studies of DSEK after failed DMEK. All studies reported significant improvement in visual acuity after secondary endothelial keratoplasty (EK). Twelve studies compared visual outcomes between primary and secondary EK, reporting conflicting findings. Sixteen studies reported endothelial cell loss rates after secondary EK, and only 1 study reported significantly increased endothelial cell loss rates compared with primary EK. Allograft rejection episodes occurred in 1.8% of eyes (range, 0%-50%). Six studies compared complication rates between primary and secondary EK eyes, and only 1 study found a higher median number of complications. However, 2 studies reported higher regraft failure rates compared with primary EK eyes. Conclusions: Secondary EK is surgically feasible and renders significant visual improvement after failed primary EK, although it is not clear whether visual outcomes and allograft survival are comparable with primary EK, raising the question of whether secondary EK eyes are "low risk" as primary EK eyes. Further larger, prospective studies are encouraged to obtain additional quality data on secondary corneal endothelial allotransplantation.info:eu-repo/semantics/publishedVersio

    The SpatialCIM methodology for spatial document coverage disambiguation and the entity recognition process aided by linguistic techniques.

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    Abstract. Nowadays it is becoming more usual for users to take into account the geographical localization of the documents in the retrieval information process. However, the conventional retrieval information systems based on key-word matching do not consider which words can represent geographical entities that are spatially related to other entities in the document. This paper presents the SpatialCIM methodology, which is based on three steps: pre-processing, data expansion and disambiguation. In the pre-processing step, the entity recognition process is carried out with the support of the Rembrandt tool. Additionally, a comparison between the performances regarding the discovery of the location entities in the texts of the Rembrandt tool against the use of a controlled vocabulary corresponding to the Brazilian geographic locations are presented. For the comparison a set of geographic labeled news covering the sugar cane culture in the Portuguese language is used. The results showed a F-measure value increase for the Rembrandt tool from 45% in the non-disambiguated process to 0.50 after disambiguation and from 35% to 38% using the controlled vocabulary. Additionally, the results showed the Rembrandt tool has a minimal amplitude difference between precision and recall, although the controlled vocabulary has always the biggest recall values.GeoDoc 2012, PAKDD 2012

    Discovering the spatial coverage of the documents through the SpatialCIM Methodology.

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    The main focus of this paper is to present the SpatialCIM methodology to identify the spatial coverage of the documents in the Brazilian geographic area. This methodology uses a linguistic tool to assist in the entity recognition process. The linguistic tool classifies the recognized entities as person, organization, time and localization, among others. The localization entities are checked using a geographic information system (GIS) in order to extract the Brazilian entity geographic paths. If there are multiple geographic paths for a single entity, the disambiguation process is carried out. This process attempts to locate the best geographic path for an entity considering all the geographic entities in the text. Another important objective of this paper is to show that the disambiguation process improves the geographic classification of the documents considering the obtained geographic paths. The validation process considers a set of news previously labeled by an expert and compared with the results of the disambiguated and non-disambiguated geographic paths. The results showed that the disambiguation process improves the classification compared with the classification without disambiguation. Keywords: Ambiguity problem resolution, spatial coverage identification, toponym resolution

    Espacialização de notícias de cana-de-açúcar utilizando entidades do IBGE.

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    O foco deste trabalho é gerar a classificação manual de notícias agrícolas, de acordo com essas divisões geográficas, para serem utilizadas no âmbito do projeto "Tecnologias Inovadoras em mineração de textos para a Espacialização de Notícias Agrícolas" (TIENA). O objetivo dessa classificação é comparar resultados de classificação automática obtida por classificadores desenvolvidos no âmbito do projeto com os resultados manuais, a fim de validar os resultados automaticamente obtidos e encontrar formas de aprimorá-los

    Identificação da cobertura espacial de documentos usando mineração de textos.

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    Resumo. Atualmente, é comum que usuários levem em consideração o contexto geográfico dos documentos nos processos de Recuperação de Informação. No entanto, os sistemas convencionais de extração de informação que estão baseados em palavras-chave não consideram que as palavras podem representar entidades geográficas espacialmente relacionadas com outras entidades nos documentos. Para resolver esse problema, é necessário viabilizar o georreferenciamento dos textos, ou seja, identificar as entidades geográficas presentes e associá-las com sua correta localização espacial. A identificação e desambiguação das entidades geográficas apresenta desafios importantes, principalmente do ponto de vista linguístico,Assim, a principal estratégia para superar os problemas de ambiguidade, compreende a identificação de evidências que auxiliem na identificação e desambiguação das localidades nos textos. O presente trabalho propõe uma metodologia que permite identificar e determinar a cobertura espacial dos documentos, denominada SpatialCIM. A metodologia SpatialCIM tem o objetivo de organizar os processos de resolução de topônimos. Para isso, foram propostas e desenvolvidas as abordagens de (1) Desambiguação por Pontos e a (2) Desambiguação Textual e Estrutural. Essas abordagens, exploram duas técnicas diferentes de desambiguação de topônimos, as quais, geram e desambiguam os caminhos geográficos associados aos topônimos reconhecidos para cada documento. A partir dos resultados obtidos, foi possível demostrar que as técnicas de desambiguação melhoram a precisão e revocação na classificação espacial dos documentos. Demonstrou-se também o impacto positivo do uso de uma ferramenta linguística no processo de reconhecimento das entidades geográficas. Assim, foi demostrada a utilidade dos processos de desambiguação para a obtenção da cobertura espacial dos documentos

    CASE STUDY: THE LIGNOCELLULOSIC COMPONENTS INTERFERENCES IN THE THERMAL BEHAVIOR OF BRAZILIAN SAVANA BIOMASS

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    The residual biomass has become increasingly important in the energy scenario due to its energetic potential and easy acquisition in isolated communities. The heterogeneous nature of biomass makes the analysis of its composition a relevant factor in the development of thermochemical processes. Several researchers show that understanding this heterogeinidade of biomass can be a strategy for optimization and search efficiency of thermochemical processes, since it is possible to predict the results and in addition, the reactor design based on the characteristics of biomass. In this context, the purpose of this work was to study the behavior of three biomass of the Brazilian savana - Dipteryx alata (baru), Hymenaea stigonocarpa (jatobá-do-cerrado) and Caryocar brasiliense (pequi), comparing the lignocellulosic results with the thermal behavior obtained by thermogravimetric analysis. The analysis were compared with results of several researchers, confirming that those analysis are parameters that influence the yield of the desired product. The results of this work elucidate that the moisture and extractives content of pequi is greater than the other biomass and that the temperature peak of cellulose and lignin from all biomass in this study are quite close. However, the hemicellulose’s temperature peak of pequi is lower than baru and jatobá’s temperature peak. Moreover, the results showed that the composition of the lignocellulosic biomass is an extremely important factor in selecting the greater reactivity material

    Random-mass Dirac fermions in an imaginary vector potential: Delocalization transition and localization length

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    One dimensional system of Dirac fermions with a random-varying mass is studied by the transfer-matrix methods which we developed recently. We investigate the effects of nonlocal correlation of the spatial-varying Dirac mass on the delocalization transition. Especially we numerically calculate both the "typical" and "mean" localization lengths as a function of energy and the correlation length of the random mass. To this end we introduce an imaginary vector potential as suggested by Hatano and Nelson and solve the eigenvalue problem. Numerical calculations are in good agreement with the results of the analytical calculations.Comment: 4 page
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