True density of soot particles: A comparison of results highlighting the influence of the organic contents

International audienc

Ficolin-2 Levels and FCN2 Haplotypes Influence Hepatitis B Infection Outcome in Vietnamese Patients

Human Ficolin-2 (L-ficolins) encoded by FCN2 gene is a soluble serum protein that plays an important role in innate immunity and is mainly expressed in the liver. Ficolin-2 serum levels and FCN2 single nucleotide polymorphisms were associated to several infectious diseases. We initially screened the complete FCN2 gene in 48 healthy individuals of Vietnamese ethnicity. We genotyped a Vietnamese cohort comprising of 423 clinically classified hepatitis B virus patients and 303 controls for functional single nucleotide polymorphisms in the promoter region (-986G>A, -602G>A, -4A>G) and in exon 8 (+6424G>T) by real-time PCR and investigated the contribution of FCN2 genotypes and haplotypes to serum Ficolin-2 levels, viral load and liver enzyme levels. Haplotypes differed significantly between patients and controls (P = 0.002) and the haplotype AGGG was found frequently in controls in comparison to patients with hepatitis B virus and hepatocellular carcinoma (P = 0.0002 and P<0.0001) conferring a protective effect. Ficolin-2 levels differed significantly between patients and controls (p<0.0001). Patients with acute hepatitis B had higher serum Ficolin-2 levels compared to other patient groups and controls.The viral load was observed to be significantly distributed among the haplotypes (P = 0.04) and the AAAG haplotype contributed to higher Ficolin-2 levels and to viral load. Four novel single nucleotide polymorphisms in introns (-941G>T, -310G>A, +2363G>A, +4882G>A) and one synonymous mutation in exon 8 (+6485G>T) was observed. Strong linkage was found between the variant -986G>A and -4A>G. The very first study on Vietnamese cohort associates both Ficolin-2 serum levels and FCN2 haplotypes to hepatitis B virus infection and subsequent disease progression

Synthesis, characterization and antibacterial activity studies of new 2‑pyrral‑L‑amino acid Schif base palladium (II) complexes.

Three new 2-pyrral amino acid Schif base palladium (II) complexes were synthesized, characterized and their activity against six bacterial species was investigated. The ligands: Potassium 2-pyrrolidine-L-methioninate (L1), Potassium 2-pyrrolidine-L-histidinate (L2) and Potassium 2-pyrrolidine-L-tryptophanate (L3) were synthesized and reacted with dichloro(1,5- cyclooctadiene)palladium(II) to form new palladium (II) complexes C1, C2 and C3, respectively. 1 NMR, FTIR, UV–Vis,elemental analysis and conductivity measurements were used to characterize the products. The antibacterial activities of the compounds were evaluated against Gram-positive Staphylococcus aureus (S. aureus, ATCC 25923), methicillin-resistant Staphylococcus aureus (MRSA, ATCC 33591), Staphylococcus epidermidis (S. epidermidis, ATCC 12228) and Streptococcus pyogenes (S. pyogenes, ATCC 19615) and, gram-negative Pseudomonas aeruginosa (P. aeruginosa, ATCC 27853) and Klebsiella pneumoniae (K. pneumoniae, ATCC 13883) using the agar well difusion assay and microtitre plate serial dilution method. The palladium complexes were active against the selected bacteria with the imidazole ring containing complex C2 and indole heterocyclic ring containing complex C3 showing the highest activity

Charging efficiency of the electrical low pressure impactor's corona charger: Influence of the fractal morphology of nanoparticle aggregates and uncertainty analysis of experimental results

The charging efficiency function of the Electrical Low Pressure Impactor (ELPI) corona charger was estimated for spherical, cubical, and fractal particles having an electrical mobility diameter Db ranging from 0.01 to 0.5 m. Uncertainty analysis was performed on the experimental results for comparison with previous results for reference aerosols (spherical and cubical). Significant discrepancies were observed for the reference aerosols relative to Marjamaki et al. (2000, 2002). For fractal particles, charging efficiency follows a power-law function; the coefficients show significant discrepancies with those estimated for the reference aerosols. Consequently, fractal particles present higher charging efficiency than reference particles with a similar electrical mobility diameter. Two approaches are proposed to estimate the equivalent charge diameter of particles denoting fractal morphology. The work of Rogak and Flagan (1992) provides the best agreement between the experimental results and the theoretical representation of the ELPI charging efficiency

Clogging of industrial pleated high efficiency particulate air (HEPA) filters in the event of fire in a confined and ventilated facility

The IRSN and AREVA NC are currently conducting a fire research programme to improve knowledge of the clogging of industrial pleated high efficiency particulate air (HEPA) filters in order to develop an empirical model for clogging of such filters by combustion aerosols. The model must insofar as possible be independent of the nature of the fuel. This paper discusses the influence of various 'direct' factors such as the filtration velocity, mass of deposited aerosols per filter area, diameter and morphology of the combustion particles, condensate content of the aerosols, and 'indirect' factors such as the air flow feeding the fire and its oxygen content, which influence evolution in the aeraulics of a clogged filter

Exploitation quantitative des mesures de masse volumique effective

National audienceYe

Relations liant les caractéristiques bidimensionnelles aux caractéristiques tridimensionnelles des agrégats de nature fractale.

National audienceYe

Morphological analysis of nanoparticles aggregates by transmission electron microscopy: from sampling to micrographs analysis

International audienceYe

Unification of effective density measurements for soot particles

International audienceYe