31 research outputs found
Modeling and hexahedral meshing of cerebral arterial networks from centerlines
Computational fluid dynamics (CFD) simulation provides valuable information
on blood flow from the vascular geometry. However, it requires extracting
precise models of arteries from low-resolution medical images, which remains
challenging. Centerline-based representation is widely used to model large
vascular networks with small vessels, as it encodes both the geometric and
topological information and facilitates manual editing. In this work, we
propose an automatic method to generate a structured hexahedral mesh suitable
for CFD directly from centerlines. We addressed both the modeling and meshing
tasks. We proposed a vessel model based on penalized splines to overcome the
limitations inherent to the centerline representation, such as noise and
sparsity. The bifurcations are reconstructed using a parametric model based on
the anatomy that we extended to planar n-furcations. Finally, we developed a
method to produce a volume mesh with structured, hexahedral, and flow-oriented
cells from the proposed vascular network model. The proposed method offers
better robustness to the common defects of centerlines and increases the mesh
quality compared to state-of-the-art methods. As it relies on centerlines
alone, it can be applied to edit the vascular model effortlessly to study the
impact of vascular geometry and topology on hemodynamics. We demonstrate the
efficiency of our method by entirely meshing a dataset of 60 cerebral vascular
networks. 92% of the vessels and 83% of the bifurcations were meshed without
defects needing manual intervention, despite the challenging aspect of the
input data. The source code is released publicly
Fecal Calprotectin Excretion in Preterm Infants during the Neonatal Period
Fecal calprotectin has been proposed as a non-invasive marker of intestinal inflammation in inflammatory bowel disease in adults and children. Fecal calprotectin levels have been reported to be much higher in both healthy full-term and preterm infants than in children and adults.To determine the time course of fecal calprotectin (f-calprotectin) excretion in preterm infants from birth until hospital discharge and to identify factors influencing f-calprotectin levels in the first weeks of life, including bacterial establishment in the gut.F-calprotectin was determined using an ELISA assay in 147 samples obtained prospectively from 47 preterm infants (gestational age, and birth-weight interquartiles 27–29 weeks, and 880–1320 g, respectively) at birth, and at 2-week intervals until hospital discharge. (p = 0.047).During the first weeks of life, the high f-calprotectin values observed in preterm infants could be linked to the gut bacterial establishment
Argatroban for an alternative anticoagulant in HIT during ECMO
Abstract Background Extracorporeal membrane oxygenation (ECMO) have become more frequently used in daily ICU practice, heparin-induced thrombocytopenia (HIT) is a rare but life-threatening complication while on extracorporeal membrane oxygenation (ECMO). HIT confirmation directly impacts on anticoagulant strategy requiring no delay unfractionated heparin discontinuation to be replaced by alternative systemic anticoagulant treatment. Case presentation We report two clinical cases of HIT occurring during ECMO in various settings with subsequent recovery with argatroban and provide literature review to help physicians treat HIT during ECMO in clinical daily practice. Conclusions HIT during ECMO is uncommon, and despite the absence of recommendation, argatroban seems to be an appropriate and safe therapeutic option. Finally, there are not enough arguments favouring routine circuit change in the event of HIT during ECM
Generalizable Features for Anonymizing Motion Signals Based on the Zeros of the Short-Time Fourier Transform
International audienc
Anonymizing motion sensor data through time-frequency domain
International audienceThe recent development of Internet of Things (IoT) has democratized activity monitoring. Even if the data collected can be useful for healthcare, sharing this sensitive information exposes users to privacy threats and re-identification. This paper presents two approaches to anonymize the motion sensor data. The first is an extension of an earlier work based on filtering in the time-frequency plane and convolutional neural network; and the second is based on handcrafted features extracted from the zeros distribution of the time-frequency representation. The two approaches are evaluated on a public dataset to assess the accuracy of activity recognition and user re-identification. With the first approach we obtained an accuracy rate in activity recognition of 73% while limiting the identity recognition to an accuracy rate of 30% which corresponds to an activity identity ratio of 2.4. With the second approach we succeeded in improving the activity and identity ratio to 2.67 by attaining an accuracy rate in activity recognition of 80% while maintaining the re-identification rate at 30%
Modeling and hexahedral meshing of cerebral arterial networks from centerlines
International audienc
Enumeration of bacteria from the Clostridium leptum subgroup in human faecal microbiota using Clep1156 16S rRNA probe in combination with helper and competitor oligonucleotides
International audienceTarget site inaccessibility represents a significant problem for fluorescent in situ hybridisation (FISH) of 16S rRNA oligonucleotide probes. For this reason, the Clep1156 probe targeting 16S rRNA of the Clostridium leptum phylogenetic subgroup used for dot blot experiments could not be used until now for FISH. Considering that bacteria from the C. leptum subgroup are very abundant in the human faecal microbiota and may play a significant role in host health, we have used unlabelled helper and competitor oligonucleotides to improve the 16S rRNA in situ accessibility and specificity of the Clep1156 probe and applied this approach to enumerate C. leptum bacteria in this ecosystem. Nine C. leptum target strains and five non-target strains were selected to develop and validate the helper-competitor strategy. Depending on the target strains, the use of helpers enhanced the fluorescence intensity signal of Clep1156 from 0.4-fold to 8.4-fold with a mean value of 3.6-fold, switching this probe from the brightness class V-VI (masked sites) to III-IV (accessible sites). The simultaneous use of helper and competitor oligonucleotides with Clep1156 probe allowed the expected specificity without disturbing in situ accessibility. Quantified by FISH combined with flow cytometry, C. leptum bacteria in human faecal samples (n=22) represented 19 +/- 7% of bacteria on average [4.9-37.5]. We conclude that helper oligonucleotides are very useful to circumvent the problem of target site in situ accessibility, especially when probe design is limited to only one 16S rRNA area and that helpers and competitors may be efficiently combined
Consommation alimentaire et apports nutritionnels chez les femmes allaitantes, en France
Une bonne alimentation pendant la période d’allaitement est un facteur important pour la santé optimale des femmes et de leur enfant. Pour autant, aucune évaluation nutritionnelle n’a été effectuée sur cette population spécifique. L’objectif de cette étude est d’évaluer pour la première fois l’apport alimentaire et nutritionnel de femmes allaitantes vivant en France métropolitaine et d’évaluer son adéquation avec les recommandations locales. L’étude s’est déroulée entre septembre et octobre 2014 sur un échantillon de 250 femmes allaitantes. La majorité des participantes étaient âgées entre 25 et 34 ans (71,5 %), avaient un niveau d’étude supérieur (bac + 1 ou plus) (60,2 %) et étaient mariées ou vivent maritalement (94,9 %). Les données de consommations alimentaires ont été recueillies avec un carnet de consommation alimentaire de 7 jours consécutifs. La majorité des participantes a renseigné le carnet sur 7 jours consécutifs (88 %). Le rythme alimentaire des participantes suit le modèle traditionnel français avec 3 repas principaux. Les participantes ingèrent en moyenne 2056 ± 51,6 g/j d’aliments et de boissons, dont plus de la moitié sous forme liquide 1168,4 ± 42,6 mL/j. L’apport moyen en eau est de 617,6 ± 36,5 mL/j. Un faible pourcentage de participantes a suivi les recommandations nutritionnelles en fruits et légumes, produits laitiers et produits céréaliers. L’apport énergétique moyen est de 1669,2 ± 32,8 kcal/j, 80 % des femmes allaitantes sont en dessous des recommandations. L’apport en protéines représente 16 % de l’apport énergétique total sans alcool. La moyenne totale d’apport de matières grasses s’élève à 66,2 ± 1,5 g/j, valeur inférieure aux recommandations. L’apport en acides gras essentiels est inférieur aux recommandations pour la quasi-totalité des femmes. L’étude suggère l’existence d’une inadéquation des apports alimentaires et nutritionnels et une faible observance des recommandations du PNNS et des Apports Nutritionnels Conseillés (ANC) chez des femmes allaitantes
Consommation alimentaire et apports nutritionnels chez les femmes allaitantes, en France
Une bonne alimentation pendant la période d’allaitement est un facteur important pour la santé optimale des femmes et de leur enfant. Pour autant, aucune évaluation nutritionnelle n’a été effectuée sur cette population spécifique. L’objectif de cette étude est d’évaluer pour la première fois l’apport alimentaire et nutritionnel de femmes allaitantes vivant en France métropolitaine et d’évaluer son adéquation avec les recommandations locales. L’étude s’est déroulée entre septembre et octobre 2014 sur un échantillon de 250 femmes allaitantes. La majorité des participantes étaient âgées entre 25 et 34 ans (71,5 %), avaient un niveau d’étude supérieur (bac + 1 ou plus) (60,2 %) et étaient mariées ou vivent maritalement (94,9 %). Les données de consommations alimentaires ont été recueillies avec un carnet de consommation alimentaire de 7 jours consécutifs. La majorité des participantes a renseigné le carnet sur 7 jours consécutifs (88 %). Le rythme alimentaire des participantes suit le modèle traditionnel français avec 3 repas principaux. Les participantes ingèrent en moyenne 2056 ± 51,6 g/j d’aliments et de boissons, dont plus de la moitié sous forme liquide 1168,4 ± 42,6 mL/j. L’apport moyen en eau est de 617,6 ± 36,5 mL/j. Un faible pourcentage de participantes a suivi les recommandations nutritionnelles en fruits et légumes, produits laitiers et produits céréaliers. L’apport énergétique moyen est de 1669,2 ± 32,8 kcal/j, 80 % des femmes allaitantes sont en dessous des recommandations. L’apport en protéines représente 16 % de l’apport énergétique total sans alcool. La moyenne totale d’apport de matières grasses s’élève à 66,2 ± 1,5 g/j, valeur inférieure aux recommandations. L’apport en acides gras essentiels est inférieur aux recommandations pour la quasi-totalité des femmes. L’étude suggère l’existence d’une inadéquation des apports alimentaires et nutritionnels et une faible observance des recommandations du PNNS et des Apports Nutritionnels Conseillés (ANC) chez des femmes allaitantes
A Proteomic- and Bioinformatic-Based Identification of Specific Allergens from Edible Insects: Probes for Future Detection as Food Ingredients
International audienceThe increasing development of edible insect flours as alternative sources of proteins added to food and feed products for improving their nutritional value, necessitates an accurate evaluation of their possible adverse side-effects, especially for individuals suffering from food allergies. Using a proteomic- and bioinformatic-based approach, the diversity of proteins occurring in currently consumed edible insects such as silkworm (Bombyx mori), cricket (Acheta domesticus), African migratory locust (Locusta migratoria), yellow mealworm (Tenebrio molitor), red palm weevil (Rhynchophorus ferrugineus), and giant milworm beetle (Zophobas atratus), was investigated. Most of them consist of phylogenetically-related protein allergens widely distributed in the different groups of arthropods (mites, insects, crustaceans) and mollusks. However, a few proteins belonging to discrete protein families including the chemosensory protein, hexamerin, and the odorant-binding protein, emerged as proteins highly specific for edible insects. To a lesser extent, other proteins such as apolipophorin III, the larval cuticle protein, and the receptor for activated protein kinase, also exhibited a rather good specificity for edible insects. These proteins, that are apparently missing or much less represented in other groups of arthropods, mollusks and nematods, share well conserved amino acid sequences and very similar three-dimensional structures. Owing to their ability to trigger allergic responses in sensitized people, they should be used as probes for the specific detection of insect proteins as food ingredients in various food products and thus, to assess their food safety, especially for people allergic to edible insects