298 research outputs found

    ETUDE DE L’ISOTHERME 25 °C DU SYSTEME QUASI QUATERNAIRE H2O - Zn(NO3)2,6H2O – Cu(NO3)2,3H2O - NH4NO3 II- ISOPLETHES : 41 MASSE % Cu(NO3)2, [MASSE DE NH4NO3] = -10/9 [MASSE DE Zn(NO3)2] + 100, [MASSE DE H2O] = 0.5702 [MASSE DE ZN(NO3)2] + 0.2879[ MASSE DE

    Get PDF
    The solid-liquid equilibria of the quasi quaternary system H2O Zn(NO3)2,6H2O Cu(NO3)2,3H2O-NH4NO3 were studied at 25°C by using a synthetic method based on conductivity measurements. Three isoplethic sections has been established at 25°C and the stable solid phases which appear are: NH4NO3 (IV), Zn(NO3)2,6H2O, Cu(NO3)2,3H2O and metastable Cu(NO3),2.5H2O. Neither double salts, nor mixed crystals are observed at these temperature and composition range

    MODELING OF THE INFLUENCE OF THERMIC TREATMENT UPON THE MECHANICAL PROPERTIES OF ALUMINUM-TIN ALLOYS

    Get PDF
    In order to master and improve the quality and properties of the final products, the major industrial challenge lies in the possibility of controlling the morphology, size of microstructures that reside within the molded pieces, as well as their defects; this is the fundamental reason according to which we are more and more interested in mastering the growth and germination of such alloys, as well as the developing structures, at the time of solidification process. The modeling reveals as a valuable aid in the mastery of the formation of such heterogeneousness: segregation cells that are incompatible with industrial requirements. The whole work focuses upon the modeling of the segregation phenomenon of the four hypoeutectic alloys, Al1%Sn, Al2%Sn, Al3%Sn and Al4%Sn, as well as the tin effect upon certain mechanical properties of aluminum. Usually, the microstructure and mechanical behavior of such alloys as Al-Sn are directly influenced by some parameters such as composition, cooling velocity and homogenization process

    INFLUENCE DU TRAITEMENT THERMIQUE ET MECANIQUE SUR LES PROPRIETES MECANIQUES ET STRUCTURALES DES ACIERS AU MANGANESE MOULES.

    Get PDF
    Molded Steel with manganese have approximately 1,2% C and 12% Mn, this high proportion of manganese gives to this alloy a stable austenitic structure on a room temperature. The experimental methods used for metallurgical studies are spark optical emission spectroscopy, optical microscopy, scanning electron microscopy, micro-hardness and hardnesss test. Steel 1 is heat-treated constitued by 15,516 % of manganese, 2,677 % of chromuim and 1,286 % of carbon. Steel 2 is mechanically treated contains 13,454 % of manganese, 1,721 % of chromuim and 1,213 % of carbon . Steel 1 has sustained quench at 1070°C, for two differents maintaining times on oven 30 and 50 minutes for a thickness of 150 millimeters then for two differents thickness 100 and 150 millimeters for a time of 50 minutes. When maintaining time on the oven increase for low dimension, surface’s alloy become more ductile. We have applied a mechanical treatement manually on steel 2 surface, his hardness increase significantly

    MODELISATION DE L'INFLUENCE DU TRAITEMENT THERMIQUE SUR LES PROPRIETES MECANIQUES DES ALLIAGES ALUMINIUM-CUIVRE (Al-Cu)

    Get PDF
    In order to master and improve the quality and properties of the final products, the major industrial challenge lies in the possibility of controlling the morphology, size of microstructures that reside within the molded pieces, as well as their defects; this is the fundamental reason according to which we are more and more interested in mastering the growth and germination of such alloys, as well as the developing structures, at the time of solidification process. The modeling reveals as a valuable aid in the mastery of the formation of such heterogeneousness: segregation cells that are incompatible with industrial requirements. The whole work focuses upon the modeling of the segregation phenomenon of the four hypoeutectic alloys, Al1%Cu, Al2%Cu, Al3%Cu et Al4%Cu, as well as the copper effect upon certain mechanical properties of aluminum. Usually, the microstructure and mechanical behavior of such alloys as Al-Cu are directly influenced by some parameters such as composition, cooling velocity and homogenization process

    Activin A is Not a Reliable Prognostic Biomarker For Bilirubin Induced Neurotoxicity in Neonates

    Get PDF
    Background: Bilirubin induced neurological dysfunction (BIND) remains an important cause of disability in developing countries. Although high total serum bilirubin (TSB) is the main instigator for BIND, different babies may have different neurological outcomes at the same TSB level. This reflects the need for a more specific predictive factor for the neurological outcome, which would allow prompt intervention and prevention of kernicterus. Aim of the Work: To assess the value of serum activin A as a predictor for acute bilirubin neurotoxicity and adverse neurodevelopmental outcomes at one year of life. Materials and Methods: The study enrolled 84 term/near-term infants admitted with indirect hyperbilirubinemia requiring intervention to the Neonatal Intensive Care Unit of Cairo University Children’s Hospital. Clinical examination, BIND score and laboratory tests including activin A were performed. Neurodevelopmental outcome was assessed at 3, 6 and 12 months using the Bayley scale of Infant Development II. Correlations between serum activin A, TSB, BIND scores and Bayley scores were studied. Results: Mean TSB level at admission was 25.92±7.14 mg/dL. BIND score at admission ranged from 0-7, and mean serum activin A level was 109.92±55 pg/ml. Activin A did not show significant correlations with TSB or BIND scores. A negative correlation between activin A level and psychomotor developmental index (PDI) at 3 months was detected however all other neurodevelopmental outcomes showed no significant correlation with activin A. Conclusion: In cases of neonatal hyperbilirubinemia, activin A is not a reliable biomarker for predicting acute or chronic bilirubin induced neurotoxicity

    Analysis and modelling of tsunami-induced tilt for the 2007, M = 7.6, Tocopilla and the 2010, M = 8.8 Maule earthquakes, Chile, from long-base tiltmeter and broadband seismometer records

    Get PDF
    We present a detailed study of tsunami-induced tilt at in-land sites, to test the interest and feasibility of such analysis for tsunami detection and modelling. We studied tiltmeter and broadband seismometer records of northern Chile, detecting a clear s

    Dietary soy and meat proteins induce distinct physiological and gene expression changes in rats

    Get PDF
    This study reports on a comprehensive comparison of the effects of soy and meat proteins given at the recommended level on physiological markers of metabolic syndrome and the hepatic transcriptome. Male rats were fed semi-synthetic diets for 1 wk that differed only regarding protein source, with casein serving as reference. Body weight gain and adipose tissue mass were significantly reduced by soy but not meat proteins. The insulin resistance index was improved by soy, and to a lesser extent by meat proteins. Liver triacylglycerol contents were reduced by both protein sources, which coincided with increased plasma triacylglycerol concentrations. Both soy and meat proteins changed plasma amino acid patterns. The expression of 1571 and 1369 genes were altered by soy and meat proteins respectively. Functional classification revealed that lipid, energy and amino acid metabolic pathways, as well as insulin signaling pathways were regulated differently by soy and meat proteins. Several transcriptional regulators, including NFE2L2, ATF4, Srebf1 and Rictor were identified as potential key upstream regulators. These results suggest that soy and meat proteins induce distinct physiological and gene expression responses in rats and provide novel evidence and suggestions for the health effects of different protein sources in human diets

    Biallelic loss of function variants in PPP1R21 cause a neurodevelopmental syndrome with impaired endocytic function

    Get PDF
    Next‐generation sequencing (NGS) has been instrumental in solving the genetic basis of rare inherited diseases, especially neurodevelopmental syndromes. However, functional workup is essential for precise phenotype definition and to understand the underlying disease mechanisms. Using whole exome (WES) and whole genome sequencing (WGS) in four independent families with hypotonia, neurodevelopmental delay, facial dysmorphism, loss of white matter, and thinning of the corpus callosum, we identified four previously unreported homozygous truncating PPP1R21 alleles: c.347delT p.(Ile116Lysfs*25), c.2170_2171insGGTA p.(Ile724Argfs*8), c.1607dupT p.(Leu536Phefs*7), c.2063delA p.(Lys688Serfs*26) and found that PPP1R21 was absent in fibroblasts of an affected individual, supporting the allele's loss of function effect. PPP1R21 function had not been studied except that a large scale affinity proteomics approach suggested an interaction with PIBF1 defective in Joubert syndrome. Our co‐immunoprecipitation studies did not confirm this but in contrast defined the localization of PPP1R21 to the early endosome. Consistent with the subcellular expression pattern and the clinical phenotype exhibiting features of storage diseases, we found patient fibroblasts exhibited a delay in clearance of transferrin‐488 while uptake was normal. In summary, we delineate a novel neurodevelopmental syndrome caused by biallelic PPP1R21 loss of function variants, and suggest a role of PPP1R21 within the endosomal sorting process or endosome maturation pathway
    corecore