BACKGROUND To evaluate the relationship between bone loss and new bone formation in ankylosing spondylitis (AS) using 10-year X-ray, dual-energy x-ray absorptiometry (DXA) and quantitative computed tomography (QCT) follow-up. METHODS Fifteen AS patients free from medical conditions and drugs affecting bone metabolism underwent X-ray, DXA and QCT in 1999 and 2009. RESULTS In spine QCT a stat...

Solutions to the energy-independent (gray) radiative transfer equations are compared to results of Monte Carlo simulations of the Ni and Co radioactive decay -ray energy deposition in supernovae. The comparison shows that an e ective, purely absorptive, gray opacity, (0:06 0:01)Ye cm 2 g , where Ye is the total number of electrons per baryon, accurately describes the interaction of -rays with t...

We use archival Chandra X-Ray Observatory data to investigate X-ray emission from early-type galaxies in the rich z = 0.06 cluster Abell 3128. By combining the X-ray count-rates from an input list of optically-selected galaxies, we obtain a statistical detection of X-ray flux, unbiased by X-ray selection limits. Using 87 galaxies with reliable Chandra data, X-ray emission is detected for galaxi...

In this work, we report synthesis of silver nanoplates by a simple reduction process of silver nitrate in the presence of polyvinyl alcohol (PVA) and N,N'-dimethyl formamide (DMF). The Characterization of the samples were carried out using X-ray diffraction (XRD), Transmission-electron microscopy (TEM) and UV-vis spectroscopy. Absorption spectra of the nanoplates in comparison with that of the ...

Two sources of X-ray emission are expected from planetary nebulae: the hot central stars with Teff > 10 5 K, and shocked fast stellar winds at temperatures of 10 − 10 K. The stellar emission and nebular emission differ in spatial distribution and spectral properties. Observations of Xray emission from PNe may provide essential information on formation mechanisms and physical conditions of PNe. ...

We report the discovery of peculiar X-ray spectral variability in the binary radio millisecond pulsar PSR J0024–7204W in the globular cluster 47 Tucanae. The observed emission consists of a dominant non-thermal component, which is eclipsed for a portion of the orbit, and a thermal component, which appears to be persistent. We propose that the non-thermal X-rays originate in a relativistic intra...

We address several issues regarding the interpretation of galactic -ray sources. We consider powerful pulsars in binaries producing X-ray and gamma-ray unpulsed emission from the shock interaction of relativistic pulsar winds with circumbinary material. Nebular mass out ows from companion stars of binary pulsars can provide the right calorimeters to transform a fraction of the electromagnetic a...

Seeding soft-X-ray plasma amplifiers with high harmonics has been demonstrated to generate high-brightness soft-X-ray laser pulses with full spatial and temporal coherence1–3. The interaction between the injected coherent field and the swept-gain medium has been modelled4,5. However, no experiment has been conducted to probe the gain dynamics when perturbed by a strong external seed field. Here...

Fluorine interaction assisted AIEE characteristic in an expanded calixbenzophyrin is presented by single-crystal X-ray-diffraction analysis and molecular modelling approaches. Selective exposure to volatile organic compounds such as ketones and esters results in the breaking of fluorine interaction, leading to enhanced monomer emission.

The interaction of N,N0-bismesitylimidazolin-2-yl (IMes) with alcohols is discussed. NMR spectroscopy and X-ray crystallography were used to examine the influence of solvent and alcohol on this interaction. The stabilizing effect of these interactions may be used for the storage of nitrogen–heterocyclic carbenes (NHCs) since removal of the volatiles liberates the NHC. 2008 Elsevier Ltd. All rig...