Effect of near‐bed turbulence on chronic detachment of epilithic biofilm: Experimental and modeling approaches.

The biomass dynamics of epilithic biofilm, a collective term for a complex microorganism community that grows on gravel bed rivers, was investigated by coupling experimental and numerical approaches focusing on epilithic biofilm‐flow interactions. The experiment was conducted during 65 days in an artificial rough open‐channel flow, where filtered river water circulated at a constant discharge. To characterize the effect of near‐bed turbulence on the chronic detachment process in the dynamics of epilithic biofilm, local hydrodynamic conditions were measured by laser Doppler anemometry and turbulent boundary layer parameters inferred from double‐averaged quantities. Numerical simulations of the EB biomass dynamics were performed using three different models of chronic detachment based upon three different descriptors for the flow conditions: Discharge Q, friction velocity u*, and roughness Reynolds number k+. Comparisons of numerical simulation results with experimental data revealed chronic detachment to be better simulated by taking the roughness Reynolds number as the external physical variable forcing chronic detachment. Indeed, the loss of epilithic matter through the chronic detachment process is related not only to hydrodynamic conditions, but also to change in bottom roughness. This suggests that changes in the behavior and dimensions of river bed roughness must be considered when checking the dynamics of epilithic biofilm in running waters

ATHLETIQUE: interest of an adapted physical activity program in patients with juvenile idiopathic arthritis: a feasibility and preliminary effectiveness study

BackgroundJuvenile Idiopathic Arthritis (JIA) is associated with joint inflammation, pain and limited joint mobility, impacting the practice of physical activities. Adapted Physical Activities (APA) are an increasingly used method of rehabilitation, but additional studies are needed to define the nature of the most appropriate physical activity for patients with JIA. The “ATHLETIQUE” project aims to evaluate the impact of a program integrating APA sessions with use of a pedometer watch, on disease activity in patients with JIA.MethodsThis study will be a randomized, multicenter, open-label, controlled clinical trial with 2 parallel arms. The patients included in this study will be children and adolescents with JIA, aged 6 to 17 years. The experimental group (30 patients) will participate in an APA program for 3 months and will use a pedometer watch for one year. We will evaluate and compare the change in disease activity measurements (primary objective), fatigue, pain, quality of life, level of physical activity, functional capacities, and muscle strength (secondary objectives) after 14, 26 and 50 weeks. The control group (10 patients) will undergo the same evaluations as the experimental group but will not participate in the APA program and will not wear the pedometer watch.Expected resultsThe APA program may help to promote an active lifestyle with regular physical activity, preventing comorbidities and motor disability. Promising results on disease activity, functional capacities and quality of life would enable us to envisage a larger research program with a view to optimizing and assessing APA for children with JIA.DiscussionThis study will be conducted in the short and medium-term, with one-year follow-up, including 3 months of APA sessions for the experimental group. The sessions proposed during the APA program will mainly be aerobic and bodyweight exercises. Furthermore, in contrast to previous studies on this topic, our study will integrate a novel element, namely the use of a pedometer watch. This watch will help to implement strategies to address motivation. This study aims to improve physical and mental well-being, provide a basis for the design of a larger study, and propose recommendations adapted to children with JIA.Trial registrationRegistered with ClinicalTrials.gov under the number NCT0557242

Mycobacterial PIMs Inhibit Host Inflammatory Responses through CD14-Dependent and CD14-Independent Mechanisms

Mycobacteria develop strategies to evade the host immune system. Among them, mycobacterial LAM or PIMs inhibit the expression of pro-inflammatory cytokines by activated macrophages. Here, using synthetic PIM analogues, we analyzed the mode of action of PIM anti-inflammatory effects. Synthetic PIM1 isomer and PIM2 mimetic potently inhibit TNF and IL-12 p40 expression induced by TLR2 or TLR4 pathways, but not by TLR9, in murine macrophages. We show inhibition of LPS binding to TLR4/MD2/CD14 expressing HEK cells by PIM1 and PIM2 analogues. More specifically, the binding of LPS to CD14 was inhibited by PIM1 and PIM2 analogues. CD14 was dispensable for PIM1 and PIM2 analogues functional inhibition of TLR2 agonists induced TNF, as shown in CD14-deficient macrophages. The use of rough-LPS, that stimulates TLR4 pathway independently of CD14, allowed to discriminate between CD14-dependent and CD14-independent anti-inflammatory effects of PIMs on LPS-induced macrophage responses. PIM1 and PIM2 analogues inhibited LPS-induced TNF release by a CD14-dependent pathway, while IL-12 p40 inhibition was CD14-independent, suggesting that PIMs have multifold inhibitory effects on the TLR4 signalling pathway

Les Infections fongiques chez les cancéreux

LYON1-BU Santé (693882101) / SudocSudocFranceF

Umpolung de nitrone induit par le diiodure de samarium (II) (application à la synthèse d'iminosucres, synthèse totale de la (+ )-hyacinthacine A2 )

Pour montrer l'intérêt de l'Umpolung de nitrone induit par Sm12, une voie de synthèse générale d'iminosucres a été proposée par couplage réducteur avec une nitrone dérivée de sucre. Selon cette approche, la synthèse totale de la (+)-hyacinthacine A2 et une synthèse formelle de la (+ )-1-désoxycastanospermine ont été réalisées. Dans le but de développer cette nouvelle réaction et d'en étudier les limites, différents accepteurs de type Michael ont été testés avec des nitrones simples ou cycliques. Finalement, la transformation de diverses nitrones dérivées de sucres en iminosucres a été étudiée. Notamment, une nouvelle méthode de déprotection d'éthers benzyliques et d'acétals par le trichlorure de bore a permis de préparer des nitrones cycliques polyhydroxylées, dérivées de sucres. L'activité biologique des iminosucres synthétisés a été évaluée sur plusieurs cibles.To highlight the interest of the nitrone Umpolung induced by Sm12, a general approach for the synthesis of iminosugars is proposed involving a reductive coupling with sugar-derived nitrones. This approach was used in the total synthesis of the (+)-hyacinthacine A2 and in a formai synthesis of the (+ )-1-deoxycastanospermine. With the aim to develop this new reaction and to study its limits, different Michael acceptors were reacted with simple and cyclic nitrones in presence of Sml20 Finally, the transformation of different sugar-derived nitrones into iminosugars was studied. Noteworthy, a new method was proposed for the deprotection of benzylic ethers and acetals with boron trichloride and it permitted the preparation of cyclic polyhydroxylated sugar-derived nitrones. The biological activity of the synthesised iminosugars was evaluated on different targets.GRENOBLE1-BU Sciences (384212103) / SudocSudocFranceF

Medical Devices Development: the Bottom-up or the Top-down Approach

International audienceBiomedical sensors are often developed under a bottom-up approach, i.e. the researcher point of view or laboratory approach. This is usually the case for microfluidic based integrated systems. The small number of such devices actually translated for use in clinical situations is mostly due to the need of sample pre-treatment by specially trained people and to the fact that industrial transfer had not been taken into account since the very beginning of the development. Conversely, the top-down approach places the end-user at the center of development discussion. In this end-user point of view approach, the participation of industrial, medical and end-users partners more often leads to the design of fully integrated and automated devices which, furthermore, can be manufactured using conventional industrial capabilities. In this opinion communication, we briefly summarize the most common biosensors technologies and we explain how immuno-combined devices may help addressing constraints related to their use in clinical situations in terms of usability by non-trained people, automation and integration

Mise en place d'une stratégie de caractérisation d'E. coli pathogène dans des eaux destinées à la production d'eau d'alimentation

Présentation à la journée scientifique annuelle de la Zone Atelier Moselle (ZAM