Broadband X-ray emission and the reality of the broad iron line from the Neutron Star - White Dwarf X-ray binary 4U 1820-30

Broad relativistic iron lines from neutron star X-ray binaries are important probes of the inner accretion disk. The X-ray reflection features can be weakened due to strong magnetic fields or very low iron abundances such as is possible in X-ray binaries with low mass, first generation stars as companions. Here we investigate the reality of the broad iron line detected earlier from the neutron star low mass X-ray binary 4U~1820--30 with a degenerate helium dwarf companion. We perform a comprehensive, systematic broadband spectral study of the atoll source using \suzaku{} and simultaneous \nustar{} \& \swift{} observations. We have used different continuum models involving accretion disk emission, thermal blackbody and thermal Comptonization of either disk or blackbody photons. The \suzaku{} data show positive and negative residuals in the region of iron K band. These features are well described by two absorption edges at 7.67\pm0.14\kev and 6.93\pm0.07\kev or partial covering photoionized absorption or by blurred reflection. Though, the simultaneous \swift{} and \nustar{} data do not clearly reveal the emission or absorption features, the data are consistent with the presence of either absorption or emission features. Thus, the absorption based models provide an alternative to the broad iron line or reflection model. The absorption features may arise in winds from the inner accretion disk. The broadband spectra appear to disfavour continuum models in which the blackbody emission from the neutron star surface provides the seed photons for thermal Comptonization. Our results suggest emission from a thin accretion disk (kT_{disk} \sim 1\kev), Comptonization of disk photons in a boundary layer most likely covering a large fraction of the neutron star surface and innermost parts of the accretion disk, and blackbody emission (kT_{bb} \sim 2\kev) from the polar regions.Comment: 12 pages, 8 figures, 5 tables. Accepted for publication in MNRA

Intensity modulated radiotherapy in carcinoma cervix with metastatic para-aortic nodes: an institutional experience from a Regional Cancer Centre of Eastern India

BACKGROUND: Cervical cancer is a major health problem, especially in developing countries like India. Extended field radiotherapy (EFRT) for cancer cervix treatment remains a challenging task for radiation oncologists. In the last decade studies have shown that EFRT using intensity modulated radiotherapy (IMRT) is feasible in treating gynaecological malignancies but there is a dearth of literature on this specific topic from this part of the world where patient profile differs greatly in several aspects from that of the western world. The aim of the study was evaluation of treatment response and toxicity profile in cases of carcinoma cervix with metastatic para-aortic nodes treated with intensity modulated radiotherapy technique. MATERIALS AND METHODS: In this retrospective study the treatment records of 45 para-aortic node positive cervical cancer patients treated with EFRT (IMRT) and concurrent cisplatin were analysed for evaluation of loco-regional control and toxicities. RESULTS: Forty-four patients received full course of treatment. Among those 44 patients, 93.2% achieved complete response. Overall, the treatment was tolerated well and toxicities were within acceptable limits. Acute grade 3-4 toxicities were observed mostly in the form of anaemia and leucopenia. Most common late toxicities were those of small and large intestine. CONCLUSION: EFRT with concurrent chemotherapy was successfully delivered for para-aortic nodes positive cervical cancer patients in Indian scenario where under-nutrition, infection, anaemia and several other factors adversely influence treatment outcome. Pelvic and para-aortic control rates were satisfactory. The technique was associated with an acceptable acute and late toxicity profile

Self-Ordered Titanium Dioxide Nanotube Arrays: Anodic Synthesis and Their Photo/Electro-Catalytic Applications

material

Light-Assisted Anodized TiO₂ Nanotube Arrays

Self-assembled arrays of titania nanotubes are synthesized via electrochemical anodization of Ti foils under the presence of UV–vis irradiation. Compared to control samples (anodized without light), the light-assisted anodized samples exhibit larger diameters as well as thicker nanotube walls, whereas the length of the nanotubes remains the same under otherwise similar synthesis conditions. Enhanced photoelectrochemical performance with light-assisted anodized samples under simulated AM 1.5 irradiation is observed by an increase in photocurrent density of 45–73% at 1.23 V (RHE). The enhanced photoelectrochemical performance is correlated to improved charge separation analyzed by Mott–Schottky. A mechanism on the photoeffect during anodization is presented. The morphology and improved properties obtained from the synthesis methodology may also find application in other fields such as sensing and catalysi

Innocuous cardiac gunshot that proved fatal: A bitter lesson learned

The management of hemodynamically normal patients with retained intra-pericardial foreign body remains a matter of conjecture. The available literature supports non-operative management of such innocuous foreign bodies. We report our experience of a hemodynamically normal patient with a retained intra-pericardial pellet from a firearm injury. He initially received successful non-operative management but developed fatal hemopericardium 21 days after injury. In this paper, we discussed the pitfalls in the management of such injuries in light of the available literature and summarized the clinical experience