105 research outputs found

    Early Weight Gain During Pregnancy: Which Women Are the Most Affected?

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    Maternal weight gain during pregnancy is a good prediction tool in short and long term health of pregnant women and their children. To study the effect of early weight gain of pregnant women until the end of the 2nd trimester of pregnancy, depending on their pre-pregnancy body mass index. 116 healthy pregnant women were followed until the 2nd trimester of pregnancy, their weight and height before pregnancy, as well as the current weight at the end of the 1st and 2nd trimesters were collected. Data included age, parity, eating habits and physical activity level. Statistics were performed using the Statview software. The mean pre-pregnancy BMI was 27 ± 5.27 kg/m². Weight gain in the 2nd trimester is 6.33 ± 4.84 kg. It decreases with the increasing age of the mother (25% of women between 20 and 24.9 years vs 12.5% of more than 35). Also, it decreases with the increasing number of children (62.5% in nulliparous vs 25% in multiparous). Breakfast is skipped by 64.5 % of overweight pregnant women in the 1st trimester and 90 % in the 2nd one. 80.17% and 69.83% of pregnant women do not practice any physical activity. Overweight and obese pregnant women before pregnancy do not take enough weight during pregnancy. Prospects will to analyze behaviors related to health and social status

    Plasma Membrane Phosphatidylinositol-4-Phosphate Is Not Necessary for Candida albicans Viability yet Is Key for Cell Wall Integrity and Systemic Infection

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    Phosphatidylinositol phosphates are key phospholipids with a range of regulatory roles, including membrane trafficking and cell polarity. Phosphatidylinositol-4-phosphate [PI(4)P] at the Golgi apparatus is required for the budding-to-filamentous-growth transition in the human-pathogenic fungus Candida albicans; however, the role of plasma membrane PI(4)P is unclear. We have investigated the importance of this phospholipid in C. albicans growth, stress response, and virulence by generating mutant strains with decreased levels of plasma membrane PI(4)P, via deletion of components of the PI-4-kinase complex, i.e., Efr3, Ypp1, and Stt4. The amounts of plasma membrane PI(4)P in the efr3Δ/Δ and ypp1Δ/Δ mutants were ∼60% and ∼40%, respectively, of that in the wild-type strain, whereas it was nearly undetectable in the stt4Δ/Δ mutant. All three mutants had reduced plas7ma membrane phosphatidylserine (PS). Although these mutants had normal yeast-phase growth, they were defective in filamentous growth, exhibited defects in cell wall integrity, and had an increased exposure of cell wall β(1,3)-glucan, yet they induced a range of hyphal-specific genes. In a mouse model of hematogenously disseminated candidiasis, fungal plasma membrane PI(4)P levels directly correlated with virulence; the efr3Δ/Δ mutant had wild-type virulence, the ypp1Δ/Δ mutant had attenuated virulence, and the stt4Δ/Δ mutant caused no lethality. In the mouse model of oropharyngeal candidiasis, only the ypp1Δ/Δ mutant had reduced virulence, indicating that plasma membrane PI(4)P is less important for proliferation in the oropharynx. Collectively, these results demonstrate that plasma membrane PI(4)P levels play a central role in filamentation, cell wall integrity, and virulence in C. albicans. Importance: While the PI-4-kinases Pik1 and Stt4 both produce PI(4)P, the former generates PI(4)P at the Golgi apparatus and the latter at the plasma membrane, and these two pools are functionally distinct. To address the importance of plasma membrane PI(4)P in Candida albicans, we generated deletion mutants of the three putative plasma membrane PI-4-kinase complex components and quantified the levels of plasma membrane PI(4)P in each of these strains. Our work reveals that this phosphatidylinositol phosphate is specifically critical for the yeast-to-hyphal transition, cell wall integrity, and virulence in a mouse systemic infection model. The significance of this work is in identifying a plasma membrane phospholipid that has an infection-specific role, which is attributed to the loss of plasma membrane PI(4)P resulting in β(1,3)-glucan unmasking.This work was supported by the CNRS, INSERM, Université Côte d’Azur, and ANR (ANR-11-LABX-0028-01, ANR-16-CE13-0010-01, and ANR-19-CE13-0004-01) grants, by grant R01DE026600 from the U.S. NIH, and grant SAF2017-86192 from the Spanish Ministry for Science and Innovation. R.G.-R. is a Prestige and Marie Curie Postdoctoral Fellow (funded in part by a PCOFUND- GA-2013-609102 coordinated by Campus France).S

    Extracting relevant predictive variables for COVID-19 severity prognosis: An exhaustive comparison of feature selection techniques

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    With the COVID-19 pandemic having caused unprecedented numbers of infections and deaths, large research efforts have been undertaken to increase our understanding of the disease and the factors which determine diverse clinical evolutions. Here we focused on a fully data-driven exploration regarding which factors (clinical or otherwise) were most informative for SARS-CoV-2 pneumonia severity prediction via machine learning (ML). In particular, feature selection techniques (FS), designed to reduce the dimensionality of data, allowed us to characterize which of our variables were the most useful for ML prognosis. We conducted a multi-centre clinical study, enrolling n=1548 patients hospitalized due to SARS-CoV-2 pneumonia: where 792, 238, and 598 patients experienced low, medium and high-severity evolutions, respectively. Up to 106 patient-specific clinical variables were collected at admission, although 14 of them had to be discarded for containing ⩾60% missing values. Alongside 7 socioeconomic attributes and 32 exposures to air pollution (chronic and acute), these became d=148 features after variable encoding. We addressed this ordinal classification problem both as a ML classification and regression task. Two imputation techniques for missing data were explored, along with a total of 166 unique FS algorithm configurations: 46 filters, 100 wrappers and 20 embeddeds. Of these, 21 setups achieved satisfactory bootstrap stability (⩾0.70) with reasonable computation times: 16 filters, 2 wrappers, and 3 embeddeds. The subsets of features selected by each technique showed modest Jaccard similarities across them. However, they consistently pointed out the importance of certain explanatory variables. Namely: patient’s C-reactive protein (CRP), pneumonia severity index (PSI), respiratory rate (RR) and oxygen levels –saturation SpO2, quotients SpO2/RR and arterial SatO2/FiO2 –, the neutrophil-to-lymphocyte ratio (NLR) –to certain extent, also neutrophil and lymphocyte counts separately–, lactate dehydrogenase (LDH), and procalcitonin (PCT) levels in blood. A remarkable agreement has been found a posteriori between our strategy and independent clinical research works investigating risk factors for COVID-19 severity. Hence, these findings stress the suitability of this type of fully data-driven approaches for knowledge extraction, as a complementary to clinical perspectives

    Imaging and pathology findings after an initial negative MRI-US fusion-guided and 12-core extended sextant prostate biopsy session

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    PURPOSEA magnetic resonance imaging-ultrasonography (MRI-US) fusion-guided prostate biopsy increases detection rates compared to an extended sextant biopsy. The imaging characteristics and pathology outcomes of subsequent biopsies in patients with initially negative MRI-US fusion biopsies are described in this study.MATERIALS AND METHODSWe reviewed 855 biopsy sessions of 751 patients (June 2007 to March 2013). The fusion biopsy consisted of two cores per lesion identified on multiparametric MRI (mpMRI) and a 12-core extended sextant transrectal US (TRUS) biopsy. Inclusion criteria were at least two fusion biopsy sessions, with a negative first biopsy and mpMRI before each.RESULTSThe detection rate on the initial fusion biopsy was 55.3%; 336 patients had negative findings. Forty-one patients had follow-up fusion biopsies, but only 34 of these were preceded by a repeat mpMRI. The median interval between biopsies was 15 months. Fourteen patients (41%) were positive for cancer on the repeat MRI-US fusion biopsy. Age, prostate-specific antigen (PSA), prostate volume, PSA density, digital rectal exam findings, lesion diameter, and changes on imaging were comparable between patients with negative and positive rebiopsies. Of the patients with positive rebiopsies, 79% had a positive TRUS biopsy before referral (P = 0.004). Ten patients had Gleason 3+3 disease, three had 3+4 disease, and one had 4+4 disease.CONCLUSIONIn patients with a negative MRI-US fusion prostate biopsy and indications for repeat biopsy, the detection rate of the follow-up sessions was lower than the initial detection rate. Of the prostate cancers subsequently found, 93% were low grade (≤3+4). In this low risk group of patients, increasing the follow-up time interval should be considered in the appropriate clinical setting

    Evaluation des fluides de forage HP/HT pour forages profonds

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    Le forage de puits profonds exige la mise au point de fluides de forage dont la formulation est adaptée aux températures élevées de formation : l'une des principales difficultés est la dégradation thermique des additifs chimiques utilisés dans les formulations à base d'eau qui se produit fréquemment lors du forage de puits à température élevée. Cette dégradation peut conduire à des variations importantes des caractéristiques rhéologiques et de filtration et à une perte de propriétés nécessaires à leur performance. De plus, même s'il n'y a pas de dégradation des composants la viscosité des solutions de polymères hydrosolubles couramment utilisés dans les formulations de fluides diminue fortement avec l'augmentation de la température au-dessus de 60°C. Une autre source de difficulté qui apparaît à forte température avec les boues à base d'eau est la gélification des argiles utilisées dans la formulation. Ce phénomène provoque une forte augmentation de la viscosité de la formulation et des pertes de charges, en particulier en cas de reprise de forage. Diverses méthodes ont été mises au point pour étudier le comportement des boues à base d'eau dans des conditions de pression et de température élevées, entre autres : - des expériences de laboratoire, pour étudier par exemple la stabilité en conditions anaérobies des solutions de polymères et le comportement rhéologique des suspensions d'argile dans des conditions de pression et de température élevées afin de simuler les caractéristiques de gélification des argiles à haute température; - des essais sur boucle d'étude HP/HT en utilisant une boucle expérimentale conçue pour étudier les fluides de forage dans des conditions de fond réalistes, c'est-à-dire des températures atteignant 180°C, des pressions atteignant 500 bar et des taux de cisaillement atteignant 10 000 s puissance( -1) Cette méthodologie a permis d'étudier un certain nombre de boues à base d'eau. Les résultats font apparaître que la nature des composants de la formulation exerce une forte influence sur le comportement de la boue dans des conditions difficiles. Le choix approprié d'additifs, tels que viscosifiants et réducteurs de filtrat, peut limiter les risques inhérents aux conditions de forage difficiles

    Durability of Hardened Portland Cement Paste used for Oilwell Cementing

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    Durability of materials used for the completion of oilwell is of utmost importance for oil and gas industry. We carried out ageing tests on a hardened cement paste in two types of fluid by varying the experimental procedure. We show that the observed alterations are highly dependent on the way of conducting the tests. To correctly assess the long-term durability of cement-based materials, it is necessary to renew periodically the ageing fluid. By doing so, a severe impairment of the macroscopic properties of an hardened cement paste aged in a monthly-replaced brine can be observed

    Étude des interactions mécaniques et physico-chimiques entre les argiles et les fluides de forage. Application à l'argile de Boom (Belgique)

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    Ce travail est motivé par les problèmes posés par la stabilité des puits forés dans des formations argileuses avec des boues de forage à base d'eau. En effet, les roches argileuses ou argilites (shales en anglais) ont la propriété d'absorber de l'eau, entraînant ainsi la déstabilisation des puits, soit par gonflement de certaines espèces minérales, soit par annulation de la pression de soutènement de la paroi par suite de la modification de la pression de pore. La déstabilisation peut être purement mécanique avec une plastification entraînant un cavage du trou, ou dépendre essentiellement des interactions physicochimiques entre le fluide de forage et l'argile. Le but de ce travail est donc de mettre expérimentalement en évidence les mécanismes susceptibles de jouer un rôle dans les phénomènes évoqués, et de tenter de quantifier l'importance de ces mécanismes pour en tenir compte dans les modèles de calcul. Le système expérimental que nous utilisons est basé sur une cellule triaxiale perméable aux rayons X, et donc destinée à un fonctionnement sous scanner (tomographie). Ce système, conçu et construit à l'Institut Français du Pétrole (IFP), est nouveau et nous avons contribué dans le cadre de ce travail à sa mise au point. La démarche consiste à mettre un échantillon d'argile sous confinement au contact avec un fluide de composition déterminée et à voir si les composants de ce fluide migrent dans l'argile ou non. Bien entendu, la tomographie ne permet que d'avoir des densités globales avec des résolutions de loin supérieures à la dimension du pore d'un matériau argileux sous confinement. Il est donc évident que les indications fournies par cette méthode doivent être complétées avec d'autres types de méthodes pour arriver à une étude sélective de la migration des éléments en solution. Pour ce qui concerne le matériau, notre choix s'est porté sur l'argile de Boom en Belgique, d'une part pour sa disponibilité et, d'autre part, pour la grande quantité d'informations disponibles sur ce matériau

    Cement-Polymer Composites for Oilwell Cementing

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    The selection of an optimal cementitious material is critical to maintain zonal isolation for the lifetime of oil & gas or gas storage wells not only for primary cementing but also after well abandonment. Polymer powder/cement composites present good mechanical and durability properties since polymer latex promotes improved adhesion and flexibility to the hardened cement paste. So, for well constructions in aggressive environment, polymer powder/cement composites would be good candidates. During the well construction, the cement slurry placement strongly depends on its rheological behaviour. In this paper, we studied rheological properties of polymer powder/cement composite suspensions: they present a transition from a gel to a liquid behaviour in oscillatory shear. The replacement of cement particles by polymer particles induces a decrease of the storage modulus in the gel state. The good quality of the polymer particle dispersion and their high affinity for cement particles were observed by Scanning Electron Microscopy (SEM). Solid state NMR (29Si and 27Al) and calorimetry allowed to highlight the influence of the polymer addition on both the hydration and hardening of the cement matrix. All these results helped us to understand the relations between the slurry composition, its rheological behaviour and the properties of the hardened materials which allowed us to design new cementing materials
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