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1.
Sci Rep ; 11(1): 11716, 2021 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-34083655

RESUMO

Pelvic fracture is one of the leading causes of death in the elderly, carrying a high risk of death within 1 year of fracture. This study proposes an automated method to detect pelvic fractures on 3-dimensional computed tomography (3D-CT). Deep convolutional neural networks (DCNNs) have been used for lesion detection on 2D and 3D medical images. However, training a DCNN directly using 3D images is complicated, computationally costly, and requires large amounts of training data. We propose a method that evaluates multiple, 2D, real-time object detection systems (YOLOv3 models) in parallel, in which each YOLOv3 model is trained using differently orientated 2D slab images reconstructed from 3D-CT. We assume that an appropriate reconstruction orientation would exist to optimally characterize image features of bone fractures on 3D-CT. Multiple YOLOv3 models in parallel detect 2D fracture candidates in different orientations simultaneously. The 3D fracture region is then obtained by integrating the 2D fracture candidates. The proposed method was validated in 93 subjects with bone fractures. Area under the curve (AUC) was 0.824, with 0.805 recall and 0.907 precision. The AUC with a single orientation was 0.652. This method was then applied to 112 subjects without bone fractures to evaluate over-detection. The proposed method successfully detected no bone fractures in all except 4 non-fracture subjects (96.4%).


Assuntos
Aprendizado Profundo , Fraturas Ósseas/diagnóstico , Imageamento Tridimensional , Redes Neurais de Computação , Ossos Pélvicos/diagnóstico por imagem , Ossos Pélvicos/patologia , Tomografia Computadorizada por Raios X , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X/métodos , Adulto Jovem
2.
Org Lett ; 10(13): 2697-700, 2008 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-18507391

RESUMO

The copper(I)-catalyzed carboxylation reaction of aryl- and alkenylboronic esters proceeded smoothly under CO(2) to give the corresponding carboxylic acid in good yield. This reaction showed wide generality with higher functional group tolerance compared to the corresponding Rh(I)-catalyzed reaction.

3.
Org Lett ; 9(7): 1251-3, 2007 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-17341089

RESUMO

[structure: see text]. A novel method for the preparation of hydroxy carboxylic acid derivatives has been developed by O2-oxidation of pi-allylnickel intermediates generated by Ni(0)-mediated coupling of 1,2-dienes with CO2.

4.
J Am Chem Soc ; 128(27): 8706-7, 2006 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-16819845

RESUMO

When the esters of arylboronic acids with 2,2-dimethylpropan-1,3-diol were treated with a catalytic amount of [Rh(OH)(cod)]2 in the presence of 1,3-bis(diphenylphosphino)propane and CsF in dioxane at 60 degrees C under carbon dioxide atmosphere, the benzoic acid derivatives were obtained in good yields. Reactions of alkenylboronic esters also proceeded under similar conditions to give alpha,beta-unsaturated carboxylic acids. As these boronic esters are now easily available through coupling or direct borylation reactions, this method would be a useful method for the preparation of various functionalized aryl- and alkenyl-carboxylic acids.


Assuntos
Ácidos Borônicos/química , Dióxido de Carbono/química , Ácidos Carboxílicos/síntese química , Ésteres/química , Ródio/química , Ácidos Carboxílicos/química , Catálise , Ligantes , Estrutura Molecular , Estereoisomerismo
5.
Chem Commun (Camb) ; (22): 2568-9, 2004 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-15543283

RESUMO

Novel bidentate amidines were designed and synthesized as easily available electron-donating N-ligands for Ni0-mediated coupling of carbon dioxide with alkynes or allenes, and high regioselectivity was achieved even for the carboxylation of aryl substituted internal alkynes.

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