The influence of radio-galaxy activity on X-ray absorption lines from the intracluster medium

We present an investigation of the X-ray absorption features predicted by hydrodynamic simulations of radio galaxies interacting with the intracluster medium (ICM) of their host galaxy clusters. We show how these absorption lines can be used as a new diagnostic for the radio-galaxy/ICM interactions. Such interactions have been observed in numerous systems by ROSAT, CHANDRA and XMM-NEWTON, and understanding them has implications for AGN feedback and galaxy formation. Starting from the hydrodynamic simulations of Reynolds, Heinz & Begelman, we calculate the properties of the highly ionized iron and oxygen lines (seen in absorption against the central active galactic nucleus; AGN), predicting line shapes, equivalent widths, column densities and velocity shifts. The main effect of the jet on the absorption lines is a reduction of the line strength from that of the quiescent ICM and the introduction of some velocity structure in the line profile. We investigate whether these features are detectable with current as well as future high-resolution X-ray spectrometers. We conclude that the CHANDRA transmission gratings have insufficient sensitivity to detect these features with high significance, and certainly would not allow a study of the dynamics of the interaction via absorption signatures. CONSTELLATION-X, on the other hand, will allow superb constraints to be derived. We can also use this analysis to assess the idea that radio-galaxy induced ICM outflows give rise to the resonant oxygen X-ray absorption lines that have been claimed as evidence for the warm-hot intergalactic medium (WHIM). We show that these detached, high-velocity oxygen absorption lines cannot result from a radio-galaxy/ICM interaction, thereby strengthening the WHIM interpretation.Comment: minor typos corrected to match the version which will be published in MNRA

Percutaneous Cell Delivery Into the Heart Using Hydrogels Polymerizing In Situ

Heart disease is the leading cause of death in the US. Following an acute myocardial infarction, a fibrous, noncontractile scar develops, and results in congestive heart failure in more than 500,000 patients in the US each year. Muscle regeneration and the induction of new vascular growth to treat ischemic disorders of the heart can have significant therapeutic implications. Early studies in patients with chronic ischemic systolic left ventricular dysfunction (SLVD) using skeletal myoblasts or bone marrow-derived cells report improvement in left ventricular ejection function (LVEF) and clinical status, without notable safety issues. Nonetheless, the efficacy of cell transfer for cardiovascular disease is not established, in part due to a lack of control over cell retention, survival, and function following delivery. We studied the use of biocompatible hydrogels polymerizable in situ as a cell delivery vehicle, to improve cell retention, survival, and function following delivery into the ischemic myocardium. The study was conducted using human bone marrow-derived mesenchymal stem cells and fibrin glue, but the methods are applicable to any human stem cells (adult or embryonic) and a wide range of hydrogels. We first evaluated the utility of several commercially available percutaneous catheters for delivery of viscous cell/hydrogel suspensions. Next we characterized the polymerization kinetics of fibrin glue solutions to define the ranges of concentrations compatible with catheter delivery. We then demonstrate the in vivo effectiveness of this preparation and its ability to increase cell retention and survival in a nude rat model of myocardial infarction

CARDIAC PARAGANGLIOMA FOUND DURING ANGINA EVALUATION

Cardiac paragangliomas are an extremely rare cause of cardiac masses. We present a case of a cardiac paraganglioma presenting as a highly vascular mass on coronary angiography in a patient with angina, we discuss the challenges in its diagnostic evaluation and management

Intramural Bowel Hematoma Presenting as Small Bowel Obstruction in a Patient on Low-Molecular-Weight Heparin

There is increasing use of low-molecular-weight heparin (LMWH) for treatment of pediatric thromboembolic disease as it has been shown to be safe and effective. It has several advantages over unfractionated heparin, such as reduced need for monitoring, easier route of administration, decreased risk of heparin-induced thrombocytopenia, and lack of drug-drug interactions. Nevertheless, LMWH still poses a bleeding risk as with any anticoagulant therapy. We present the case of a 4-year-old boy who was placed on LMWH for a catheter-related deep venous thrombosis in the setting of intractable seizures and subsequently developed a small bowel obstruction secondary to a suspected intussusception. He underwent exploratory laparotomy and was found to have an intramural bowel hematoma. Prior to this bleed, the patient had been monitored daily, and his anti-Xa levels were found to be in the therapeutic range. This case highlights the need for a high index of suspicion for spontaneous bleeding even in the setting of therapeutic anti-Xa levels

QUATUOR A CORDES N °6 EN RE MINEUR OP. POSTHUME ; LA JEUNE FILLE ET LA MORT / Franz SCHUBERT ; QUATUOR KOECKERT

Titre uniforme : [Quatuors. Cordes. No 14. D 810. Ré mineur]BnF-Partenariats, Collection sonore - BelieveContient une table des matière