Extreme nonlinear dynamics in the filamentation regime

[no abstract

The accretion environment in Vela X-1 during a flaring period using XMM-Newton

We present analysis of 100 ks contiguous XMM-Newton data of the prototypical wind accretor Vela X-1. The observation covered eclipse egress between orbital phases 0.134 and 0.265, during which a giant flare took place, enabling us to study the spectral properties both outside and during the flare. This giant flare with a peak luminosity of $3.92^{+0.42}_{-0.09} \times 10^{37}$ erg s$^{-1}$ allows estimates of the physical parameters of the accreted structure with a mass of $\sim$ $10^{21}$ g. We have been able to model several contributions to the observed spectrum with a phenomenological model formed by three absorbed power laws plus three emission lines. After analysing the variations with orbital phase of the column density of each component, as well as those in the Fe and Ni fluorescence lines, we provide a physical interpretation for each spectral component. Meanwhile, the first two components are two aspects of the principal accretion component from the surface of the neutron star, and the third component seems to be the \textit{X-ray light echo} formed in the stellar wind of the companion.Comment: Accepted. Astronomy and Astrophysics, 201

Impact of spatial inhomogeneities on on-axis pulse reconstruction in femtosecond filaments

We demonstrate a strong influence of the spatial beam profile on the vacuum-propagated on-axis pulse shapes for a femtosecond filament in argon. The effects can be minimized by transmitting the filament into the far-field by a laser-drilled pinhole setup. Using this method, we can monitor the pulse compression dynamics along the entire longitudinal extension of the filament, including the ionization-induced plasma channel

Spatial contributions of electron trajectories to high-order-harmonic radiation originating from a semi-infinite gas cell

We report on the analysis of the spatial beam profile of high-order harmonic radiation originating from a semi-infinite gas cell (SIGC). We experimentally assign contributions of electron trajectories to different spatial regions of the harmonic radiation beam. The angular divergence of the harmonic radiation is studied for the first time in a SIGC as a function of different phase-matching parameters. We relate the ratio of the dipole phase coefficients to the coherence time and divergence angle measurements. Simulations, including high-order-harmonic propagation, give further insight into the generation process and the influence of phase matching. The analysis reveals that the SIGC enables tuning of the cutoff frequency by altering the absorption of the generating medium.The authors thank Vasily V. Strelkov and Pascal Salie`res for valuable discussions and the Deutsche Forschungsge- meinschaft DFG and the Cluster of Excellence QUEST for financial support of this work. Carlos Hernández-García and Luis Plaja acknowledge support from Junta de Castilla y León (Consejería de Educación and Fondo Social Europeo) and Spanish MINECO (FIS2009-09522)

Bimetallic Carbonyl Complexes Based on Iridium and Rhodium: Useful Tools for Hydrodefluorination Reactions

A set of bimetallic complexes based on iridium and rhodium with bis(diphenylphosphino)methane, bis(di‐iso‐propylphosphino)methane, diphenyl‐2‐pyridylphosphine and 2‐(di‐iso‐propylphosphino)imidazole bridging ligands was prepared. The complexes were characterized by NMR and IR spectroscopy and studied quantum‐chemically using DFT methods. The bimetallic systems succeeded in catalytic hydrodefluorination reactions of lower fluorinated aryl fluorides using molecular hydrogen and sodium tert‐butoxide as a base. Effects of (i) ligand variation, (ii) mono‐ vs bimetallic nuclearity, and (iii) Ir vs Rh metal identity were studied and rationalized en route to achieve an effective hydrodefluorination.Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)Peer Reviewe

Femoral Arterial Thrombosis After Cardiac Catheterization In Infancy: Impact of Doppler Ultrasound for Diagnosis

Femoral arterial thrombosis (FAT) is a nonnegligible complication after cardiac catheterization (CC) in infancy. The aim of this study was to evaluate the impact of Doppler ultrasound (US) for diagnostic work-up after catheterization. We compared standard follow-up (FU) without Doppler US by relying on clinical signs of FAT with advanced FU using Doppler US of the femoral vessels. Between January and December 2009, we evaluated the rate of FAT in infants <12months of age using a multicenter, prospective observational survey. We analysed 171 patients [mean age 4.1±3.3 (SD) months; mean body weight 5.3±1.8kg] from 6 participating centres. The mean duration of catheter studies was 57.7±38.0min. The overall rate of FAT based on clinical diagnosis was 4.7% and was comparable in both groups [3.4% undergoing standard FU vs. 7.4% undergoing advanced FU (p=0.15)]. However, the overall rate of thrombosis as screened by Doppler US was greater at 7.1%, especially in patients after advanced FU [18.5% advanced vs. standard FU 1.7% (p<0.01)]. In conclusion, FAT remains a relevant and underestimated complication after catheterization in young infants when relying only on clinical signs of FAT. Therefore, to start effective treatment as soon as possible, we recommend Doppler US to be performed the day after C

Compact realization of all-attosecond pump-probe spectroscopy

The ability to perform attosecond-pump attosecond-probe spectroscopy (APAPS) is a longstanding goal in ultrafast science. While first pioneering experiments demonstrated the feasibility of APAPS, the low repetition rates (10-120 Hz) and the large footprints of existing setups have so far hindered the widespread exploitation of APAPS. Here we demonstrate two-color APAPS using a commercial laser system at 1 kHz, straightforward post-compression in a hollow-core fiber and a compact high-harmonic generation (HHG) setup. The latter enables the generation of intense extreme-ultraviolet (XUV) pulses by using an out-of-focus HHG geometry and by exploiting a transient blueshift of the driving laser in the HHG medium. Near-isolated attosecond pulses are generated, as demonstrated by one-color and two-color XUV-pump XUV-probe experiments. Our concept allows selective pumping and probing on extremely short timescales and permits investigations of fundamental processes that are not accessible by other pump-probe techniques.Comment: 8 pages, 5 figure

Risk Factors and Outcomes of Children with Congenital Heart Disease on Extracorporeal Membrane Oxygenation-A Ten-Year Single-Center Report.

For children born with congenital heart defects (CHDs), extracorporeal life support may be necessary. This retrospective single-center study aimed to investigate the outcomes of children with CHDs on extracorporeal membrane oxygenation (ECMO), focusing on various risk factors. Among the 88 patients, 36 (41%) had a single-ventricle heart defect, while 52 (59%) had a biventricular defect. In total, 25 (28%) survived, with 7 (8%) in the first group and 18 (20%) in the latter. A p-value of 0.19 indicated no significant difference in survival rates. Children with biventricular hearts had shorter ECMO durations but longer stays in the intensive care unit. The overall rate of complications on ECMO was higher in children with a single ventricle (odds ratio [OR] 1.57, 95% confidence interval [CI] 0.67-3.7); bleeding was the most common complication in both groups. The occurrence of a second ECMO run was more frequent in patients with a single ventricle (22% vs. 9.6%). ECMO can be effective for children with congenital heart defects, including single-ventricle patients. Bleeding remains a serious complication associated with worse outcomes. Patients requiring a second ECMO run within 30 days have lower survival rates