Development of an apparatus for obtaining molecular beams in the energy range from 2 to 200 eV

The formation and detection of molecular beams obtained by charge exchange from a low-energy ion source is discussed. Dispersion in energy of the ion source was measured and problems concerning detection of neutral beams were studied. Various methods were used, specifically secondary electron emissivity of a metallic surface and ionization of a gas target with a low ionization voltage. The intensities of neutral beams as low as 10 eV are measured by a tubular electron multiplier and a lock-in amplifier

Malignant Leakage After Sleeve Gastrectomy: Endoscopic and Surgical Approach

PURPOSE: Gastric leak occurs after sleeve gastrectomy (SG) in 2% of cases. Most staple-line disruptions (SLD) can be successfully treated with first-line endoscopic procedures. Less favorable situations may lead to more complex therapeutic strategies, like conversion to Roux-en-Y gastric bypass (RYGBP). The aim of our study is to predict the factors of endoscopic treatment failure and to assess the safety of conversion to RYGBP. METHODS: We included all patients treated in two centers of academic excellence (n = 100) between 2013 and 2017 who had a malignant SLD after SG. A "malignant" leakage met one of the following poor prognosis criteria suggested in the literature: unsuccessfully treated by the first-line endoscopic treatment; generalized peritonitis; anatomical anomalies; gastro-cutaneous or gastro-pleural fistula (GCF/GPF); or chronic leaks (\textgreater 4 weeks). RESULTS: No deaths occurred during the follow-up (20 ± 12 months). The endoscopy reported an anatomically abnormal gastric tube in 35 (35%) patients (stenosis [n = 21 (21%)], twist [n = 9 (9%)], or both [n = 5 (5%)]). We could maintain the SG in place in 92% of cases without stenosis, twist, or GCF/GPF. Conversion to RYGBP due to leakage was necessary in 37 (37%) patients. Stenosis, twist, or GCF/GPF significantly prevented healing in multivariate analysis (respectively: p = 0.020, OR = 0.17, and p \textless 0.001, OR = 0.07-logistic regression). CONCLUSION: Endoscopy is the treatment of choice for the management of chronic leaks after SG. The association of anatomical anomalies and GCF/GPF should lead to consideration of conversion to RYGBP

Florent Jacquemard,

Tree automata with equality constraints modulo equational theorie

Antioxidant activity of isocoumarins isolated from Paepalanthus bromelioides on mitochondria

The isocoumarins (1-50 mu M) paepalantine (9,10-dihydroxy-5,7-dimethoxy-1H-naptho(2,3c)pyran-1-one), 8,8 '-paepalantine dimer, and vioxanthin isolated from Paepalanthus bromelioides, were assessed for antioxidant activity using isolated rat liver mitochondria and non-mitochondrial systems, and compared with the flavonoid quercetin. The paepalantine and paepalantine dimers, but not vioxanthin, were effective at scavenging both 1,1-diphenyl-2-picrylhydrazyl (DPPH*) and superoxide (O-2(-)) radicals in non-mitochondrial systems, and protected mitochondria from tert-butylhydroperoxide-induced H2O2 accumulation and Fe2+ -citrate-mediated mitochondrial membrane lipid peroxidation, with almost the same potency as quercetin. These results point towards paepalantine, followed by paepalantine dimer, as being a powerful agent affording protection, apparently via O-2(-) scavenging, from oxidative stress conditions imposed on mitochondria, the main intracellular source and target of those reactive oxygen species. This strong antioxidant action of paepalantine was reproduced in HepG2 cells exposed to oxidative stress condition induced by H2O2. (C) 2007 Elsevier Ltd. All rights reserved