Flare-induced fountains and buried flares in AGN

We discuss the local physical changes at the surface of an AGN accretion disk after the onset of a magnetic flare. The X-ray irradiation by a flare creates a hot spot at the disk surface where the plasma both heats up and expands in the vertical direction in order to regain the hydrostatic equilibrium. Assuming that the magnetic loop causing the flare is anchored deeply within the disk interior, we derive analytical estimates for the vertical dimension H_hot and the optical depth tau_es of the heated atmosphere as a function of the position within the spot. We perform computations for various values of the accretion rate dm/dt, the fraction f_cor of radiation dissipated within the disk corona, and the covering factor f_cover of the disk surface with flare-illuminated patches. It turns out that generally we can distinguish three characteristic radial zones within the disk showing a qualitatively different behavior of the heated material. In the innermost regions of the disk (inner zone) the expansion of the disk material is restricted by strong gravitational forces. Further out, the flare source, initially above the disk, soon becomes embedded by the expanding disk atmosphere. At these intermediate disk radii (middle zone) the material is optically thick thus greatly modifying the observed radiation by multiple Compton scattering. We show exemplary spectra models obtained from Monte Carlo simulations illustrating the trends. In the outermost regions of the disk (outer zone) the expanding material is optically thin and its influence on the observed spectra is smaller but pressure gradients in radial directions should cause the development of a fountain-like dynamical structure around the flare source. We discuss the observational consequences of our results.Comment: 12 pages, 14 figures, accepted by Astronomy & Astrophysic

A systematic review of the effectiveness of antimicrobial rinse-free hand sanitizers for prevention of illness-related absenteeism in elementary school children

BACKGROUND: Absenteeism due to communicable illness is a major problem encountered by North American elementary school children. Although handwashing is a proven infection control measure, barriers exist in the school environment, which hinder compliance to this routine. Currently, alternative hand hygiene techniques are being considered, and one such technique is the use of antimicrobial rinse-free hand sanitizers. METHODS: A systematic review was conducted to examine the effectiveness of antimicrobial rinse-free hand sanitizer interventions in the elementary school setting. MEDLINE, EMBASE, Biological Abstract, CINAHL, HealthSTAR and Cochrane Controlled Trials Register were searched for both randomized and non-randomized controlled trials. Absenteeism due to communicable illness was the primary outcome variable. RESULTS: Six eligible studies, two of which were randomized, were identified (5 published studies, 1 published abstract). The quality of reporting was low. Due to a large amount of heterogeneity and low quality of reporting, no pooled estimates were calculated. There was a significant difference reported in favor of the intervention in all 5 published studies. CONCLUSIONS: The available evidence for the effectiveness of antimicrobial rinse-free hand sanitizer in the school environment is of low quality. The results suggest that the strength of the benefit should be interpreted with caution. Given the potential to reduce student absenteeism, teacher absenteeism, school operating costs, healthcare costs and parental absenteeism, a well-designed and analyzed trial is needed to optimize this hand hygiene technique

A phase I study of intravenous liposomal daunorubicin (DaunoXome) in paediatric patients with relapsed or resistant solid tumours

Anthracyclines are widely used in paediatric oncology, but their use is limited by the risk of cumulative cardiac toxicity. Encapsulating anthracyclines in liposomes may reduce cardiac toxicity and possibly increase drug availability to tumours. A phase I study in paediatric patients was designed to establish the dose limiting toxicity (DLT) and maximum tolerated dose (MTD) after a single course of liposomal daunorubicin, ‘DaunoXome', as a 1 h infusion on day 1 of a 21 day cycle. Patients were stratified into two groups according to prior treatment: Group A (conventional) and group B (heavily pretreated patients). Dose limiting toxicity was expected to be haematological, and a two-step escalation was planned, with and without G-CSF support. Pharmacokinetic studies were carried out in parallel. In all, 48 patients aged from 1 to 18 years were treated. Dose limiting toxicity was neutropenia for both groups. Maximum tolerated dose was defined as 155 mg m−2 for Group A and 100 mg m−2 for Group B. The second phase with G-CSF was interrupted because of evidence of cumulative cardiac toxicity. Cardiac toxicity was reported in a total of 15 patients in this study. DaunoXome shares the early cardiotoxicity of conventional anthracyclines in paediatric oncology. This study has successfully defined a haematological MTD for DaunoXome, but the significance of this is limited given the concerns of delayed cardiac toxicity. The importance of longer-term follow-up in patients enrolled into phase I studies has been underestimated previously, and may lead to an under-recognition of important adverse events

Legumes as food ingredient: characterization, processing, and applications

Editores: Jiménez-López, José Carlos (CSIC); Clemente, Alfonso (CSIC

Dietary Oat Bran Increases Some Proinflammatory Polyunsaturated Fatty-Acid Oxidation Products and Reduces Anti-Inflammatory Products in Apolipoprotein E^−/− Mice

International audienceOat bran is suggested to attenuate atherosclerotic conditions by regulating dyslipidemia, endothelial function, and oxidative damage. Through the measurement of oxidized polyunsaturated fatty acid (PUFA), oxidative stress, and inflammation status in liver and heart tissues of apolipoprotein E-/- (ApoE -/- ), mice fed with high fat diet (HFD) or HFD with oat bran (HFD + Oat) were investigated. Using liquid chromatography tandem mass spectrometry (LC-MS/MS), PUFA and over 40 types of its oxidized products were assessed. The HFD + Oat group had augmented adrenic acid (ADA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) and suppressed n-3 docosapentaenoic acid levels in the liver tissues compared to the HFD group. Arachidonic acid (ARA) and α-linolenic acid (ALA) levels were elevated and ADA was suppressed in the heart tissues of the HFD + Oat group compared to the HFD group. Furthermore, enzymatically mediated oxidized ARA product levels (9-, 11- and 20-HETE [hydroxyeicosatetraenoic acid], and PGF2α ) were augmented and those of the oxidized DHA products (4-, 7-, 10-, 11-, 13-, and 14-HDHA [hydroxy-docosahexaenoic acid]) were reduced in the liver tissues of the HFD + Oat group. It also increased 17-F2t -dihomo-isoprostane and 7-F2t -dihomo-isofuran derived from nonenzymatic oxidation of ADA in the heart and liver tissues, and those from ALA namely 16-F1t -phytoprostane and 16(RS)-13-epi-STΔ14 -9-phytofuran. Our study showed oat bran to be a weak antioxidant and lacked anti-inflammatory properties in atherosclerotic mice. Elevation of oxidized PUFA products that are potentially proinflammatory and vasoconstrictors (HETE, PGF2α ) with simultaneous reduction of those that are anti-inflammatory (HDHA) may not be desirable in the pathogenesis of atherosclerosis