279 research outputs found

    Une nouvelle technologie pour les échanges thermiques : le Nanofluide

    Get PDF
    Les nanofluides sont des solutions colloïdales composées de particules de taille nanométrique en suspension dans un liquide. Leurs propriétés thermiques étonnantes en ont fait l'objet d'intenses investigations durant la dernière décennie. On constate, notamment, une nette augmentation des échanges de chaleur qu'aucune phénoménologie ne permet encore d'expliquer de manière satisfaisante. Cette amélioration du transfert de chaleur fait donc des nanofluides une nouvelle technologie prometteuse dans le cadre des transferts thermiques, permettant d'améliorer les performances de divers échangeurs de chaleurs. Dans cette étude, on s'intéressera particulièrement à des solutions à base de nanotubes de carbone, qui ont montré une très bonne capacité à augmenter le coefficient de transfert de chaleur en convection forcée

    Continuous CaO/Ca(OH)2 Fluidized Bed Reactor for Energy Storage: First Experimental Results and Reactor Model Validation

    Get PDF
    This document is the Accepted Manuscript version of a Published Work that appeared in final form in Industrial and Engineering Chemistry Research, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/acs.iecr.6b04105Novel thermochemical energy storage systems that employ fluidized beds of CaO/Ca(OH)2 for hydration/dehydration reactions are under development because of the inherent advantages of the low cost of the materials and their relatively high temperature operation windows (450 °C–550 °C). We report in this work the results of the first steady state experiments conducted in a new pilot plant designed to test the concept under realistic reactor conditions. The pilot has a fluidized bed reactor with an internal diameter of 0.108 m and a height of 780 mm fed continuously with gas and solids as well as heat exchangers to supply/extract the required reaction heat. The experimental results during dynamic and steady state periods were fitted to a KL reactor bubbling bed model, using kinetic parameters from thermogravimetric studies and a single crossflow factor. The resulting continuous reactor model will serve as useful tool for the continued scaling up of this technology.Financial support provided by the European Commission under the 7th Framework Program (StoRRe Project GA 282677) is acknowledged.Peer reviewe

    Активація м’язів плечового пояса та плеча людини в перебігу двосуглобових рухів руки, що виконуються при дії зовнішніх навантажень протилежних напрямів

    Get PDF
    У дослідах на чотирьох добровольцях досліджувалася координація центральних рухових команд (ЦРК), що керували повільними двосуглобовими рухами руки в горизонтальній площині. Як кореляти інтенсивності таких команд розглядались поточні амплітуди ЕМГ, відведених від шести м’язів плечового пояса і плеча й підданих повному випрямленню та низькочастотній фільтрації. Зокрема, досліджували залежність координації ЦРК від напрямку зовнішньої сили, яка прикладалася до дистальної частини передпліччя. Як виявилося, координація ЦРК істотно залежить від напрямку сили, що згинає ліктьовий суглоб. Згідно з результатами дослідження, ЕМГ певних м’язів у разі виконання двосуглобового руху може бути представлена як лінійна комбінація ЕМГ, зареєстрованих у перебігу послідовних односуглобових рухів в умовах пересування референтної точки кисті в ту ж саму точку операційного простору, що й при двосуглобовому русі. Отримані дані можуть вважатися підтвердженням принципу суперпозиції елементарних ЦРК під час виконання складних рухів кінцівок

    Developmental and Tumor Angiogenesis Requires the Mitochondria-Shaping Protein Opa1

    Get PDF
    While endothelial cell (EC) function is influenced by mitochondrial metabolism, the role of mitochondrial dynamics in angiogenesis, the formation of new blood vessels from existing vasculature, is unknown. Here we show that the inner mitochondrial membrane mitochondrial fusion protein optic atrophy 1 (OPA1) is required for angiogenesis. In response to angiogenic stimuli, OPA1 levels rapidly increase to limit nuclear factor kappa-light-chain-enhancer of activated B cell (NFκB) signaling, ultimately allowing angiogenic genes expression and angiogenesis. Endothelial Opa1 is indeed required in an NFκB-dependent pathway essential for developmental and tumor angiogenesis, impacting tumor growth and metastatization. A first-in-class small molecule-specific OPA1 inhibitor confirms that EC Opa1 can be pharmacologically targeted to curtail tumor growth. Our data identify Opa1 as a crucial component of physiological and tumor angiogenesis

    Reference Group Choice and Antibiotic Resistance Outcomes

    Get PDF
    Two types of cohort studies examining patients infected with methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) were contrasted, using different reference groups. Cases were compared to uninfected patients and patients infected with the corresponding, susceptible organism. VRE and MRSA were associated with adverse outcomes. The effect was greater when uninfected control patients were used

    Safety and effectiveness of isavuconazole in real-life non-neutropenic patients

    Full text link
    Objectives: Information is scarce on clinical experiences with non-neutropenic patients with invasive fungal infection (IFI) receiving isavuconazole. We aimed to report the safety and effectiveness of this drug as a first-line treatment or rescue in real life. Methods: A retrospective, observational multicentric study of non-neutropenic patients who received isavuconazole as an IFI treatment at 12 different university hospitals (January 2018-2022). All patients met criteria for proven, probable or possible IFI according to EORTC-MSG. Results: A total of 238 IFIs were treated with isavuconazole during the study period. Combination therapy was administered in 27.7% of cases. The primary IFI was aspergillosis (217, 91.2%). Other IFIs treated with isavuconazole were candidemia (n = 10), mucormycosis (n = 8), histoplasmosis (n = 2), cryptococcosis (n = 2), and others (n = 4). Median time of isavuconazole treatment was 29 days. Only 5.9% (n = 14) of cases developed toxicity, mainly hepatic-related (10 patients, 4.2%). Nine patients (3.8%) had treatment withdrawn. Successful clinical response at 12 weeks was documented in 50.5% of patients. Conclusion: Isavuconazole is an adequate treatment for non-neutropenic patients with IFIs. Toxicity rates were low and its effectiveness was comparable to other antifungal therapies previously reported. (c) 2024 The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/

    A biobank of pediatric patient-derived-xenograft models in cancer precision medicine trial MAPPYACTS for relapsed and refractory tumors

    Get PDF
    Pediatric patients with recurrent and refractory cancers are in most need for new treatments. This study developed patient-derived-xenograft (PDX) models within the European MAPPYACTS cancer precision medicine trial (NCT02613962). To date, 131 PDX models were established following heterotopical and/or orthotopical implantation in immunocompromised mice: 76 sarcomas, 25 other solid tumors, 12 central nervous system tumors, 15 acute leukemias, and 3 lymphomas. PDX establishment rate was 43%. Histology, whole exome and RNA sequencing revealed a high concordance with the primary patient's tumor profile, human leukocyte-antigen characteristics and specific metabolic pathway signatures. A detailed patient molecular characterization, including specific mutations prioritized in the clinical molecular tumor boards are provided. Ninety models were shared with the IMI2 ITCC Pediatric Preclinical Proof-of-concept Platform (IMI2 ITCC-P4) for further exploitation. This PDX biobank of unique recurrent childhood cancers provides an essential support for basic and translational research and treatments development in advanced pediatric malignancies

    Screening of protein kinase inhibitors identifies PKC inhibitors as inhibitors of osteoclastic acid secretion and bone resorption

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Bone resorption is initiated by osteoclastic acidification of the resorption lacunae. This process is mediated by secretion of protons through the V-ATPase and chloride through the chloride antiporter ClC-7. To shed light on the intracellular signalling controlling extracellular acidification, we screened a protein kinase inhibitor library in human osteoclasts.</p> <p>Methods</p> <p>Human osteoclasts were generated from CD14+ monocytes. The effect of different kinase inhibitors on lysosomal acidification in human osteoclasts was investigated using acridine orange for different incubation times (45 minutes, 4 and 24 hours). The inhibitors were tested in an acid influx assay using microsomes isolated from human osteoclasts. Bone resorption by human osteoclasts on bone slices was measured by calcium release. Cell viability was measured using AlamarBlue.</p> <p>Results</p> <p>Of the 51 compounds investigated only few inhibitors were positive in both acidification and resorption assays. Rottlerin, GF109203X, Hypericin and Ro31-8220 inhibited acid influx in microsomes and bone resorption, while Sphingosine and Palmitoyl-DL-carnitine-Cl showed low levels of inhibition. Rottlerin inhibited lysosomal acidification in human osteoclasts potently.</p> <p>Conclusions</p> <p>In conclusion, a group of inhibitors all indicated to inhibit PKC reduced acidification in human osteoclasts, and thereby bone resorption, indicating that acid secretion by osteoclasts may be specifically regulated by PKC in osteoclasts.</p
    corecore