398 research outputs found

    Cardiac and inflammatory biomarkers do not correlate with volume of heart or lung receiving radiation

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    Background: Thoracic and cardiac irradiation increases the risk of pulmonary and cardiovascular disease. In addition, radiation, often in combination with chemotherapy, can cause treatment-related pneumonitis. Previously, we showed that the common marker for cardiac damage, troponin T, was not elevated by chemoradiation [Lung Cancer 62:351–355, 2008]. In this study, we explore whether dose-volume metrics and biomarkers for cardiac damage, inflammation or angiogenesis could identify patients receiving thoracic radiation who would later have cardiac or pulmonary complications. Findings: To this end, we quantified cardiac biomarkers including c-reactive protein (cRP) as well as a panel of angiogenic and inflammatory molecules in thirty patients who received radiation therapy to the thorax with or without concurrent chemotherapy between May 2006 and May 2007. Serum was collected at baseline, 2 weeks into radiation treatment and at the completion of radiation therapy. Heart and lung dosimetric parameters and clinical risk factors were also examined, along with the monitoring of adverse pulmonary and cardiac events during follow-up. Contrary to our hypothesis, there was no correlation between serum biomarker levels and cardiac radiation dose. Similarly there was little association between lung dose-volume metrics and inflammatory or angiogenic biomarkers. Furthermore, there was no correlation with serum biomarkers and adverse pulmonary or cardiovascular events. Conclusion: Based on these data, acute elevations in serum biomarkers of cardiac damage, inflammation or angiogenesis should not be attributed to thoracic (chemo)radiation and elevations in such biomarkers of tissue damage should be further evaluated

    The Galactic Exoplanet Survey Telescope (GEST)

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    The Galactic Exoplanet Survey Telescope (GEST) will observe a 2 square degree field in the Galactic bulge to search for extra-solar planets using a gravitational lensing technique. This gravitational lensing technique is the only method employing currently available technology that can detect Earth-mass planets at high signal-to-noise, and can measure the frequency of terrestrial planets as a function of Galactic position. GEST's sensitivity extends down to the mass of Mars, and it can detect hundreds of terrestrial planets with semi-major axes ranging from 0.7 AU to infinity. GEST will be the first truly comprehensive survey of the Galaxy for planets like those in our own Solar System.Comment: 17 pages with 13 figures, to be published in Proc. SPIE vol 4854, "Future EUV-UV and Visible Space Astrophysics Missions and Instrumentation

    Multi-Institutional Data Collection and Analysis via the Pediatric Proton/Photon Consortium Registry

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    Care of patients with proton therapy has increased in the past decade. It is important to report on outcomes and disease specific utilization of particle therapy. In this chapter, we review our experience in developing a registry for pediatric patients treated with radiation to assess outcomes and provide a platform for shared research interests

    Planetary Microlensing at High Magnification

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    Simulations of planetary microlensing at high magnification that were carried out on a cluster computer are presented. It was found that the perturbations due to two-thirds of all planets occur in the time interval [-0.5t_FWHM, 0.5t_ FWHM] with respect to the peak of the microlensing light curve, where t_FWHM is typically about 14 hours. This implies that only this restricted portion of the light curve need be intensively monitored for planets, a very significant practical advantage. Nearly all planetary detections in high magnification events will not involve caustic crossings. We discuss the issues involved in determining the planetary parameters in high magnification microlensing events. Earth mass planets may be detected with 1-m class telescopes if their projected orbital radii lie within about 1.5 - 2.5 AU. Giant planets are detectable over a much larger region. For multi-planet systems the perturbations due to individual planets can be separated under certain conditions. The size of the source star needs to be determined independently, but the presence of spots on the source star is likely to be negligible, as is the effect of planetary motion during an event.Comment: 12 pages, 13 embedded figures, accepted for publication by MNRA

    GRB 091029: At the limit of the fireball scenario

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    Using high-quality, broad-band afterglow data for GRB 091029, we test the validity of the forward-shock model for gamma-ray burst afterglows. We used multi-wavelength (NIR to X-ray) follow-up observations obtained with the GROND, BOOTES-3/YA and Stardome optical ground-based telescopes, and the UVOT and the XRT onboard the Swift satellite. To explain the almost totally decoupled light curves in the X-ray and optical/NIR domains, a two-component outflow is proposed. Several models are tested, including continuous energy injection, components with different electron energy indices and components in two different stages of spectral evolution. Only the last model can explain both the decoupled light curves with asynchronous peaks and the peculiar SED evolution. However, this model has so many unknown free parameters that we are unable to reliably confirm or disprove its validity, making the afterglow of GRB 091029 difficult to explain in the framework of the simplest fireball model.Comment: Accepted to A&
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