De l'analyse d'un système alimenté sur le secteur à l'intégration fonctionnelle de sa commande

Le domaine de l'électroménager grand public est un secteur d'activité à fort volume de production, où l'augmentation des fonctionnalités proposées ainsi que diverses contraintes sociétales(économie d'énergie, réduction de la consommation d'eau, ou du bruit acoustique)se font de plus en plus pressantes . De ce fait, une grande partie des actionneurs implémentés ont dû être adaptés ou remplacés . Cela engendra l'émergence de nombreux actionneurs spécifiques et originaux dont le comportement s'éloigne bien souvent des caractéristiques des charges traditionnellement étudiées dans l'enseignement supérieur . D'autre part, l'électronique est de plus en plus présente dans ce secteur . La réalisation d'un circuit de commande adapté passe par une bonne connaissance de l'application et des contraintes qui y sont associées, sous peine de choisir un composant qui, bien que performant ne soit pas adapté à la fonction . De ce fait, le principe de fonctionnement de divers actionneurs a été explicité et une étude théorique sommaire, permettant la compréhension des phénomènes rencontrés, a été menée . Ensuite, une analyse comportementale détaillée nous a permis d'extraire les paramètres électriques imposés par chaque actionneur et de déterminer l'impact de ces contraintes sur le composant de commande . L'étude de la commutation des triacs à l'ouverture a été abordée et les résultats obtenus, associés à l'analyse comportementale préalable, ont conduit au développement d'une nouvelle structure intégrée dans la filière ASD de STMicroelectronics . Cette nouvelle solution de commande dédiée permet la commande d'électroaimants ou de moteurs universels par une tension redressée double alternance .TOURS-BU Sciences Pharmacie (372612104) / SudocSudocFranceF

Analysis of Electrical stresses in AC Switches Used for Control of Small Power Motors Present in Household Appliances

This paper describes a study on electric and thermal stresses induced in bidirectional switches used for control of small power motors present in household appliances, in order to find out the possible weakness of the current solution generally made of a triac and to determine the requirements for new dedicated devices in the ASDTM technology. First, a behavioral analysis of these motors must be performed and the interactions between the switch and the load have to be well defined

Comparison of 10 enzyme immunoassays for detection of antibody to human immunodeficiency virus type 2 in West African sera.

The efficacies of nine enzyme-linked immunosorbent assays (EIA) for antibody to human immunodeficiency virus type 1 (HIV-1) and one EIA for antibody to HIV-2 in detecting antibody to HIV-2 were studied. The competitive EIAs for antibody to HIV-1 were less sensitive than the indirect EIAs. The overall prevalence of positive results was between 28 and 51% with the competitive EIAs and between 70 and 93% with the indirect EIAs. Most of the EIAs were less sensitive in detecting antibody to HIV-2 in sera from people with acquired immunodeficiency syndrome-like diseases than in sera from symptomless individuals. The results indicate that there is a high degree of cross-reactivity between HIV-1 and HIV-2 by EIA, indicating that serotype specificity must be determined by Western blot (immunoblot) with both sets of viral antigens. The results are relevant for discussing public health strategies, especially the screening of blood donors; competitive EIAs for antibody to HIV-1 are not sensitive enough to be used in areas where HIV-2 is prevalent (West Africa)

GFP-transduced CD34+ and Lin- CD34- hematopoietic stem cells did not adopt a cardiac phenotype in a nonhuman primate model of myocardial infarct.

International audienceOBJECTIVE: Studies in mice have reported contradictory results on the contribution of bone marrow cells to myocardial regeneration. This study aims to evaluate their ability to differentiate into cells of cardiac lineage in a nonhuman primate mode of myocardial infarct. MATERIALS AND METHODS: Lin(-)CD34(-) and CD34(+)-enriched bone marrow cells or mobilized peripheral blood cells were transduced with green fluorescent protein (GFP) and injected directly into ischemic myocardium. The fate of the transplanted cells was evaluated using quantitative reverse transcription polymerase chain reaction (QRT-PCR) and immunohistology. Animals were followed-up using echocardiography. RESULTS: QRT-PCR analysis detected from 3% to 10% of the original number of administered GFP(+) cells after 7 days. These GFP(+) cells did not express cardiac tissue-specific markers, but were immunophenotypically consistent with undifferentiated hematopoietic cells. The local production of vascular endothelial growth factor, measured by QRT-PCR, was approximately doubled as compared to the untreated infarcted control heart. Three months after hematopoietic stem cell (HSC) administration, no GFP(+) cells were detected and no evidence of regeneration of the infarcted region was found by histological examination. In contrast, a high level of matrix metalloproteinase 2 was measured in infarct and peri-infarct area. At this time, an improved ejection fraction and decreased left ventricular chamber dimension, which might be also related to a natural course after reperfusion, were observed. CONCLUSIONS: Our data show that GFP(+) CD34(+) and Lin(-)CD34(-)-enriched HSC do not differentiate into cardiomyocytes or into endothelial cells in the infarcted myocardium and that the local production of some growth factors had no positive effect on myocardial regeneration after 3 months

Defining biomarkers in oral cancer according to smoking and drinking status

International audienceIntroduction Oral Squamous Cell Carcinomas (OSCC) are mostly related to tobacco consumption eventually associated to alcohol (Smoker/Drinker patients: SD), but 25-30% of the patients have no identified risk factors (Non-Smoker/Non-Drinker patients: NSND). We hypothesized that these patients have distinguishable immune profiles that could be useful for prognosis. Materials and Methods Cells present in immune tumor microenvironment (TME) and blood from 87 OSCC HPV-negative patients were analyzed using a multiparameter flow cytometry assay, in a prospective case-control study. Cytokine levels in tumor supernatants and blood were determined by a cytometric bead array (CBA) assay. Results Normal gingiva and blood from healthy donors (HD) were used as controls. A significant increase of granulocytes (p<0.05 for blood), of monocytes-macrophages (p<0.01 for blood) and of CD4 + T cells expressing CD45RO and CCR6 (p<0.001 for blood; p<0.0001 for TME) as well as higher levels of IL-6 (p<0.01 for sera, p<0.05 for tumor supernatant) were observed in SD patients as compared to NSND OSCC patients and HD. High percentages of CD4 + T cells expressing CD45RO and CCR6 cells in tumor tissue (p=0.05) and blood (p=0.05) of SD OSCC patients were also associated with a poorer prognosis while a high percentage of regulatory T cells (Treg) in tumor tissue was associated with a more favorable prognostic factor (p=0.05). Also, a higher percentage of blood CD8 + T lymphocytes among CD45 + cells in NSND patients was associated with a better disease-free survival (p=0.004). Conclusion Granulocytes, monocytes-macrophages, and CD4 + T cells expressing CD45RO and CCR6 in blood and TME as well as serum IL-6 can therefore distinguish OSCC SD and NSND patients. Quantifying the proportion of CD4 + T cells expressing CD45RO and CCR6 and of Treg in SD patients and CD8 + T cells in NSND patients could help defining the prognostic of OSCC patients

Functional evidence for derivation of systemic histiocytic neoplasms from hematopoietic stem/progenitor cells

International audienceLangerhans cell histiocytosis (LCH) and the non-LCH neoplasm Erdheim-Chester disease (ECD) are heterogeneous neoplastic disorders marked by infiltration of pathologic macrophage-, dendritic cell-, or monocyte-derived cells in tissues driven by recurrent mutations activating MAPK signaling. Although recent data indicate that at least a proportion of LCH and ECD patients have detectable activating kinase mutations in circulating hematopoietic cells and bone marrow-based hematopoietic progenitors, functional evidence of the cell of origin of histiocytosis from actual patient materials has long been elusive. Here, we provide evidence for mutations in MAPK signaling intermediates in CD34+ cells from patients with ECD and LCH/ECD, including detection of shared origin of LCH and acute myelomonocytic leukemia driven by TET2-mutant CD34+ cell progenitors in one patient. We also demonstrate functional self-renewal capacity for CD34+ cells to drive the development of histiocytosis in xenotransplantation assays in vivo. These data indicate that the cell of origin of at least a proportion of patients with systemic histiocytoses resides in hematopoietic progenitor cells prior to committed monocyte/macrophage or dendritic cell differentiation and provide the first example of a patient-derived xenotransplantation model for a human histiocytic neoplasm

Cutaneous manifestations of lymphoid-variant hypereosinophilic syndrome

International audienc

HIV-1 Nef protein expression in human CD34(+) progenitors impairs the differentiation of an early T/NK cell precursor.

International audienceHIV-1 impairs the production of T cells, through mechanisms that are still unknown. Here, we investigated the effect of the expression of HIV-1 Nef on the T-cell potential of human hematopoietic CD34(+) precursors. Those progenitors were transduced by using lentiviral vectors expressing Nef and cultured on OP9-DL1 cells allowing the differentiation of T cell from human hematopoietic precursors. We demonstrate that Nef impairs the generation of a CD3varepsilon(+)CD5(+) CD1a(+) precursor stage that has initiated a D-J rearrangement of the TCRbeta locus. Onward stages of T-cell development were also affected with a quantitative reduction of CD4(+) intraCD3varepsilon(+) Immature single positive cells (ISP), Double Positive (DP) CD4(+)CD8(+) TCRalphabeta T cells and CD56(+) NK cells. But B cell production was not affected. Limiting dilution analyses demonstrated a significant reduction in the frequency of T/NK progenitors among Nef-expressing CD34(+) cells. Altogether, these data demonstrate that Nef interferes with the differentiation of a primitive lymphoid human precursor with a T/NK potential