33 research outputs found

    Automatic eduction and statistical analysis of coherent structures in the wall region of a confine plane

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    This paper describes a vortex detection algorithm used to expose and statistically characterize the coherent flow patterns observable in the velocity vector fields measured by Particle Image Velocimetry (PIV) in the impingement region of air curtains. The philosophy and the architecture of this algorithm are presented. Its strengths and weaknesses are discussed. The results of a parametrical analysis performed to assess the variability of the response of our algorithm to the 3 user-specified parameters in our eduction scheme are reviewed. The technique is illustrated in the case of a plane turbulent impinging twin-jet with an opening ratio of 10. The corresponding jet Reynolds number, based on the initial mean flow velocity U0 and the jet width e, is 14000. The results of a statistical analysis of the size, shape, spatial distribution and energetic content of the coherent eddy structures detected in the impingement region of this test flow are provided. Although many questions remain open, new insights into the way these structures might form, organize and evolve are given. Relevant results provide an original picture of the plane turbulent impinging jet

    Monocarboxylate transporter 8 modulates the viability and invasive capacity of human placental cells and fetoplacental growth in mice

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    Monocarboxylate transporter 8 (MCT8) is a well-established thyroid hormone (TH) transporter. In humans, MCT8 mutations result in changes in circulating TH concentrations and X-linked severe global neurodevelopmental delay. MCT8 is expressed in the human placenta throughout gestation, with increased expression in trophoblast cells from growth-restricted pregnancies. We postulate that MCT8 plays an important role in placental development and transplacental TH transport. We investigated the effect of altering MCT8 expression in human trophoblast in vitro and in a Mct8 knockout mouse model. Silencing of endogenous MCT8 reduced T3 uptake into human extravillous trophoblast-like cells (SGHPL-4; 40%, P<0.05) and primary cytotrophoblast (15%, P<0.05). MCT8 over-expression transiently increased T3 uptake (SGHPL-4∶30%, P<0.05; cytotrophoblast: 15%, P<0.05). Silencing MCT8 did not significantly affect SGHPL-4 invasion, but with MCT8 over-expression T3 treatment promoted invasion compared with no T3 (3.3-fold; P<0.05). Furthermore, MCT8 silencing increased cytotrophoblast viability (∼20%, P<0.05) and MCT8 over-expression reduced cytotrophoblast viability independently of T3 (∼20%, P<0.05). In vivo, Mct8 knockout reduced fetal:placental weight ratios compared with wild-type controls at gestational day 18 (25%, P<0.05) but absolute fetal and placental weights were not significantly different. The volume fraction of the labyrinthine zone of the placenta, which facilitates maternal-fetal exchange, was reduced in Mct8 knockout placentae (10%, P<0.05). However, there was no effect on mouse placental cell proliferation in vivo. We conclude that MCT8 makes a significant contribution to T3 uptake into human trophoblast cells and has a role in modulating human trophoblast cell invasion and viability. In mice, Mct8 knockout has subtle effects upon fetoplacental growth and does not significantly affect placental cell viability probably due to compensatory mechanisms in vivo

    Body mass index variations in patients with Parkinson's disease treated with levodopa-carbidopa intestinal gel infusion: A case control study versus standard of care and subthalamic nucleus deep brain stimulation

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    International audienceBackground: Levodopa-carbidopa intestinal gel (LCIG) is an advanced therapy for patients with Parkinson Disease (PD). Weight loss has been pointed out as an adverse event of LCIG infusion.Aims of the study: To compare weight changes between three groups of PD patients: patients treated with LCIG, patients within the first year of subthalamic deep brain stimulation (STN-DBS) and patients treated exclusively with oral treatment during 1 year of follow up.Methods: Patients treated with LCIG were retrospectively matched by age, gender, disease duration and Hoehn and Yahr to patients undergoing STN-DBS and to patients both receiving the standard of care treatment and unwilling advanced therapies (SOC). Clinical features and weight were collected at baseline, and 12 months after introducing the treatment (LCIG and STN-DBS groups) or for one year of treatment (SOC).Results: Eighteen patients were included in each group. They had no differences in clinical and demographic features, except for cognitive impairment. There was a mean weight (-5.8kg ±6.8) and BMI (-2.1kg/m2±2.6) reduction in the LCIG group after 12 months, while there was a slight weight loss in the SOC (-1.4kg ±3.1) and a weight increase in the STN-DBS group (5.4kg ±4.7). Differences of weight were statistically different between, LCIG and STN-DBS (P<0.001), LCIG and SOC (P=0.002) and STN-DBS and SOC (P<0.001).Conclusions: The study shows a significant weight reduction after starting LCIG infusion compared to the other groups. Weight loss should be closely monitored in patients treated with LCIG

    Adhesion of the genome-sequenced Lactococcus lactis subsp. cremoris IBB477 strain is mediated by specific molecular determinants

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    Understanding the nature of mucus-microbe interactions will provide important information that can help to elucidate the mechanisms underlying probiotic adhesion. This study focused on the adhesive properties of the Lactococcus lactis subsp. cremoris IBB477 strain, previously shown to persist in the gastrointestinal tract of germ-free rats. The shear flow-induced detachment of L. lactis cells was investigated under laminar flow conditions. Such a dynamic approach demonstrated increased adhesion to bare and mucin-coated polystyrene for IBB477, compared to that observed for the MG1820 control strain. To identify potential genetic determinants giving adhesive properties to IBB477, the improved high-quality draft genome sequence comprising chromosome and five plasmids was obtained and analysed. The number of putative adhesion proteins was determined on the basis of surface/extracellular localisation and/or the presence of adhesion domains. To identify proteins essential for the IBB477 specific adhesion property, nine deletion mutants in chromosomal genes have been constructed and analysed using adhesion tests on bare polystyrene as well as mucin-, fibronectin- or collagen IV-coated polystyrene plates in comparison to the wild-type strain. These experiments demonstrated that gene AJ89_07570 encoding a protein containing DUF285, MucBP and four Big_3 domains is involved in adhesion to bare and mucin-coated polystyrene. To summarise, in the present work, we characterised the adhesion of IBB477 under laminar flow conditions; identified the putative adherence factors present in IBB477, which is the first L. lactis strain exhibiting adhesive and mucoadhesive properties to be sequenced and demonstrated that one of the proteins containing adhesion domains contributes to adhesion

    Effects of Light Intensity and Reaction Temperature on Photoreactions in Commercial Photoreactors

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    In the last decade, visible‐light photoredox catalysis has evolved into a versatile tool in organic synthesis. However, most reports have used homemade photoreactors in their design and optimisation of new methods, complicating the reproducibility of some transformations. To improve reproducibility as well as efficiency, laboratory photoreactors have been developed and commercialized. Herein we report a comparison of four commercially available photoreactors in six mechanistically distinct photoredox reactions focusing on the difference in product yields and kinetics as well as the factors, which lead to these differences including reaction temperature and light intensity
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