Evaluation of Two New Commercial Tests for the Diagnosis of Acute Dengue Virus Infection Using NS1 Antigen Detection in Human Serum

Dengue is a viral disease transmitted by mosquitoes that is endemic in more than 100 countries in tropical areas, threatening over 2.5 billion people. It causes a wide range of symptoms and has severe forms. In reference laboratories, dengue disease is confirmed by virus isolation or genome detection during the acute phase, and by serological methods during the early convalescent phase. The viral NS1 protein circulates in the sera of infected patients throughout the clinical phase of the disease. Novel diagnostic tests based on NS1 detection have been recently developed and marketed. We compared the performance of two tests for detecting dengue NS1 protein during the clinical phase of dengue infection (an immunochromatographic test (ICT) from Bio-Rad allowing rapid detection of the NS1 antigen and a two-step sandwich-format ELISA from Panbio) with the one-step sandwich-format microplate ELISA (Bio-Rad). The ICT test performed better than the ELISA test from Panbio. This study confirms that diagnostic tests based on NS1 could be used in routine clinical practice in poorly equipped laboratories and that dengue diagnosis could therefore be confirmed without the need for testing in reference laboratories. This represents a crucial step towards the control of dengue disease in the human population

About the inevitable compromise between spatial resolution and accuracy of strain measurement for bone tissue: A 3D zero-strain study

The accurate measurement of local strain is necessary to study bone mechanics and to validate micro computed tomography (μCT) based finite element (FE) models at the tissue scale. Digital volume correlation (DVC) has been used to provide a volumetric estimation of local strain in trabecular bone sample with a reasonable accuracy. However, nothing has been reported so far for μCT based analysis of cortical bone. The goal of this study was to evaluate accuracy and precision of a deformable registration method for prediction of local zero-strains in bovine cortical and trabecular bone samples. The accuracy and precision were analyzed by comparing scans virtually displaced, repeated scans without any repositioning of the sample in the scanner and repeated scans with repositioning of the samples.The analysis showed that both precision and accuracy errors decrease with increasing the size of the region analyzed, by following power laws. The main source of error was found to be the intrinsic noise of the images compared to the others investigated. The results, once extrapolated for larger regions of interest that are typically used in the literature, were in most cases better than the ones previously reported. For a nodal spacing equal to 50 voxels (498. μm), the accuracy and precision ranges were 425-692. με and 202-394. με, respectively. In conclusion, it was shown that the proposed method can be used to study the local deformation of cortical and trabecular bone loaded beyond yield, if a sufficiently high nodal spacing is used

Experimental validation of finite element models of intact and implanted composite hemi-pelvises using digital image correlation

A detailed understanding of the changes in load transfer due to implantation is necessary to identify potential failure mechanisms of orthopaedic implants. Computational finite element (FE) models provide full field data on intact and implanted bone structures, but their validity must be assessed for clinical relevance. The aim of this study was to test the validity of FE predicted strain distributions for the intact and implanted pelvis using the digital image correlation (DIC) strain measurement technique. FE models of an in-vitro hemi-pelvis test setup were produced, both intact and implanted with an acetabular cup. Strain predictions were compared to DIC and strain rosette measurements. Regression analysis indicated a strong linear relationship between the measured and predicted strains, with a high correlation coefficient (R = 0.956 intact, 0.938 implanted) and a low standard error of the estimate (SE = 69.53, 75.09µ?). Moreover, close agreement between the strain rosette and DIC measurements improved confidence in the validity of the DIC technique. The FE model therefore was supported as a valid predictor of the measured strain distribution in the intact and implanted composite pelvis models, confirming its suitability for further computational investigations

Photoelasticimetrie en grandes deformations : methode de mesures de grandes et de petites deformations

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Influence de l'anomalie génétique "malformation vertébrale complexe" sur le taux de gestation raccourcie en race holstein

L'objectif était d'étudier l'influence du statut CVM du taureau et de la vache sur le taux de gestations raccourcies en tenant compte de facteurs d'ajustements classiquement cités comme influençant la durée de gestation. Cette étude a été réalisée d'une part, sur la gestation globale (0-297 jours) et d'autre part sur une période considérée comme la plus à risque quant au risque de gestation raccourcie (150-275 jours chez les vaches, 144-269 jours chez les génisses).NANTES-Ecole Nat.Vétérinaire (441092302) / SudocSudocFranceF

Analyse mécanique de la verse en végétation du maïs, approche expérimentale et élaboration d'un modèle numérique du système racinaire

POITIERS-BU Sciences (861942102) / SudocSudocFranceF