An Investigation of Chlorine Ligands in Transition-Metal Complexes via 35Cl Solid-State NMR and Density Functional Theory Calculations

35Cl solid state NMR (SSNMR), in tandem with 35Cl NQR and density functional theory calculations, was used to characterize chlorine ligands in a series of transition-metal complexes exhibiting structural motifs common to organometallic catalysts. The differentiation of the various chlorine environments was possible, and insight into the origins of the 35Cl electric field gradient tensor parameters was provided. The applicability of 35Cl SSNMR to the study of surface supported transition-metal complexes was demonstrated, validating the use of this technique in the characterization of heterogeneous catalysts

OSMAC Method to Assess Impact of Culture Parameters on Metabolomic Diversity and Biological Activity of Marine-Derived Actinobacteria

peer reviewedActinobacteria are known for their production of bioactive specialized metabolites, but they are still under-exploited. This study uses the “One Strain Many Compounds” (OSMAC) method to explore the potential of three preselected marine-derived actinobacteria: Salinispora arenicola (SH-78) and two Micromonospora sp. strains (SH-82 and SH-57). Various parameters, including the duration of the culture and the nature of the growth medium, were modified to assess their impact on the production of specialized metabolites. This approach involved a characterization based on chemical analysis completed with the construction of molecular networks and biological testing to evaluate cytotoxic and antiplasmodial activities. The results indicated that the influence of culture parameters depended on the studied species and also varied in relation with the microbial metabolites targeted. However, common favorable parameters could be observed for all strains such as an increase in the duration of the culture or the use of the A1 medium. For Micromonospora sp. SH-82, the solid A1 medium culture over 21 days favored a greater chemical diversity. A rise in the antiplasmodial activity was observed with this culture duration, with a IC50 twice as low as for the 14-day culture. Micromonospora sp. SH-57 produced more diverse natural products in liquid culture, with approximately 54% of nodes from the molecular network specifically linked to the type of culture support. Enhanced biological activities were also observed with specific sets of parameters. Finally, for Salinispora arenicola SH-78, liquid culture allowed a greater diversity of metabolites, but intensity variations were specifically observed for some metabolites under other conditions. Notably, compounds related to staurosporine were more abundant in solid culture. Consequently, in the range of the chosen parameters, optimal conditions to enhance metabolic diversity and biological activities in these three marine-derived actinobacteria were identified, paving the way for future isolation works

The impact of drinking water, indoor dust and paint on blood lead levels of children aged 1-5 years in Montreal (Quebec, Canada)

Lead is neurotoxic at very low dose and there is a need to better characterize the impact of domestic sources of lead on the biological exposure of young children. A cross-sectional survey evaluated the contribution of drinking water, house dust and paint to blood lead levels (BLLs) of young children living in old boroughs of Montreal (Canada). Three hundred and six children aged 1 to 5 years and currently drinking tap water participated in the study. For each participant, residential lead was measured in kitchen tap water, floor dust, windowsill dust and house paint and a venous blood sample was analyzed. Multivariate logistic regression was used to evaluate the association between elevated BLL in the children (>/= 75th percentile) and indoor lead contamination by means of odds ratios (OR) using 95% confidence intervals (CI). There was an association between BLL >/=75th percentile (1.78 mug/dL) and water lead when the mean water concentration was >3.3 mug/L: adjusted OR=4.7 (95% CI: 2.1-10.2). Windowsill dust loading >14.1 mug/ft(2) was also associated with BLL >/=1.78 mug/dL: adjusted OR=3.2 (95% CI: 1.3-7.8). Despite relatively low BLLs, tap water and house dust lead contribute to an increase of BLLs in exposed young children

Médecine hyperbare et systèmes d'informations (Création de la plateforme internet du centre hyperbare du C.H.U. de Marseille)

AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Ordre et désordre dans les matériaux, l’apport de la RMN à hauts champs magnétiques

National audienc

Advanced solid-state NMR as a key tool for the deeper understanding of heterogeneous catalysts

International audienc

Lemierre Syndrome: Two Preschool Children with Cerebral Infarcts

We report two children who developed hemiparesis secondary to cerebral infarcts complicating Lemierre syndrome. The first case is a one-year-old patient who presented a left internal jugular vein thrombosis and a left carotid compression due to retropharyngeal cellulitis. The second case is a five-year-old girl who presented a left internal jugular vein and a right carotid artery thrombosis associated with an oropharyngeal cellulitis. Etiologic agents involved were Staphylococus aureus in the first case and Fusobacterium necrophorum in the second case. These cases call for vigilance among physicians for this rare syndrome, its unusual presentation and its associated severe complications

17 O MAS NMR studies of oxo-based olefin metathesis catalysts: a critical assessment of signal enhancement methods

International audienceThe DFS enhancement method as applied to 17O MAS NMR was critically assessed, first on NaPO3, a simple binary glass system, and in a second step, on a series of catalysis-related organometallic molecules and materials. The robustness of DFS was investigated for the wide range of anisotropic parameters (quadrupolar coupling and chemical shift anisotropy) encountered in these samples. Emphasis has been put on the variation of signal enhancements with respect to the DFS final sweep frequency, pulse amplitude and pulse duration, while line shape distortion issues were also addressed. Finally, the robustness of DFS enhancement of the 17O MAS NMR signal is shown through its successful application to silica-supported olefin metathesis catalysts