5D operando tomographic diffraction imaging of a catalyst bed.

We report the results from the first 5D tomographic diffraction imaging experiment of a complex Ni-Pd/CeO2-ZrO2/Al2O3 catalyst used for methane reforming. This five-dimensional (three spatial, one scattering and one dimension to denote time/imposed state) approach enabled us to track the chemical evolution of many particles across the catalyst bed and relate these changes to the gas environment that the particles experience. Rietveld analysis of some 2 × 106 diffraction patterns allowed us to extract heterogeneities in the catalyst from the Å to the nm and to the µm scale (3D maps corresponding to unit cell lattice parameters, crystallite sizes and phase distribution maps respectively) under different chemical environments. We are able to capture the evolution of the Ni-containing species and gain a more complete insight into the multiple roles of the CeO2-ZrO2 promoters and the reasons behind the partial deactivation of the catalyst during partial oxidation of methane.

Therapeutic drug monitoring in pediatrics: a need for improvement.

Therapeutic drug monitoring (TDM) is practiced for a number of frequently used drugs in infants and children. It is believed that monitoring drug levels will increase the probability of a therapeutic response and minimize the probability of adverse drug sequelae. Dose adjustments are based on measured drug levels interpreted relative to published therapeutic ranges which may or may not reflect the true relationship with either therapeutic or adverse effects. Potential errors derive from many sources, some amenable to solutions based on current knowledge, others awaiting improved understanding of the causes and consequences of unreliable therapeutic ranges.

[Percutaneous endoscopic gastrostomy: its value in assisted alimentation in malnutrition in elderly patients. Apropos of 101 consecutive cases in patients over 70 years of age]. / La gastrostomie percutanée endoscopique: intérêt dans l'alimentation assistée du sujet âgé dénutri. A propos de 101 cas consécutifs chez des patients âgés de 70 ans et plus.

This is a prospective study concerning 101 percutaneous endoscopic gastrostomies (PEG) performed in patients aged from 70 to 98 (83.6). We obtained a success in 99%. Indications were stroke and its consequences in 36%, dementia in 22%, depressive syndrome in 38% (7% in the postoperative period) laryngeal or oesophageal tumors in 4%. This technique was carried out in outpatients without anesthesia but PEG must be considered to be a surgical method. Only 5% patients presented major immediate complications with three deaths (3%) due to the technique. Follow-up (30 days) demonstrated 11 other deaths. Would earlier PEG have given better results? Oral feedings (alone or both oral and PEG) were possible in 51% patients. PEG is a valuable technique of feeding assistance in the aged, offering an alternative to nasogastric tube and could be used more extensively in old patients.

Normal fetal outcome after maternal ciguateric toxin exposure in the second trimester.

A case of a severe episode of ciguatera poisoning in a mother during the second trimester is presented. The mother experienced an increase of fetal movements one hour after the poisonous meal. She endured multisystemic symptoms typical of ciguatera for eight weeks. The presence of ciguatoxin in the fish was confirmed by immunoassay and two bioassays. The newborn at term was normal with adequate respiratory and neurological reflexes. The child developed normally in his first 10 months. This is in contrast with another report of a mother exposed to ciguatoxin at term who delivered an infant suffering from facial palsy and possible myotonia of the hands. Dose and gestational timing may explain these observed differences.