238 research outputs found

    Continuum Halos in Nearby Galaxies -- an EVLA Survey (CHANG-ES) -- II: First Results on NGC 4631

    Full text link
    We present the first results from the CHANG-ES survey, a new survey of 35 edge-on galaxies to search for both in-disk as well as extra-planar radio continuum emission. The motivation and science case for the survey are presented in a companion paper (Paper I). In this paper (Paper II), we outline the observations and data reduction steps required for wide-band calibration and mapping of EVLA data, including polarization, based on C-array test observations of NGC 4631. With modest on-source observing times (30 minutes at 1.5 GHz and 75 minutes at 6 GHz for the test data) we have achieved best rms noise levels of 22 and 3.5 μ\muJy beam−1^{-1} at 1.5 GHz and 6 GHz, respectively. New disk-halo features have been detected, among them two at 1.5 GHz that appear as loops in projection. We present the first 1.5 GHz spectral index map of NGC 4631 to be formed from a single wide-band observation in a single array configuration. This map represents tangent slopes to the intensities within the band centered at 1.5 GHz, rather than fits across widely separated frequencies as has been done in the past and is also the highest spatial resolution spectral index map yet presented for this galaxy. The average spectral index in the disk is αˉ1.5GHz = −0.84 ± 0.05\bar\alpha_{1.5 GHz}\,=\,-0.84\,\pm\,0.05 indicating that the emission is largely non-thermal, but a small global thermal contribution is sufficient to explain a positive curvature term in the spectral index over the band. Two specific star forming regions have spectral indices that are consistent with thermal emission. Polarization results (uncorrected for internal Faraday rotation) are consistent with previous observations and also reveal some new features. On broad scales, we find strong support for the notion that magnetic fields constrain the X-ray emitting hot gas.Comment: Accepted to the Astronomical Journal, Version 2 changes: Added acknowledgement to NRA

    Proton pump inhibitors (PPIs) impact on tumour cell survival, metastatic potential and chemotherapy resistance, and affect expression of resistance-relevant miRNAs in esophageal cancer

    Get PDF
    This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Background Neoadjuvant treatment plays a crucial role in the therapy of advanced esophageal cancer. However, response to radiochemotherapy varies widely. Proton pump inhibitors (PPIs) have been demonstrated to impact on chemotherapy in a variety of other cancers. We analyzed the impact of PPI treatment on esophageal cancer cell lines, and investigated mechanisms that mediate the effect of PPI treatment in this tumour. Methods We investigated the effect of esomeprazole treatment on cancer cell survival, adhesion, migration and chemotherapy in human adeno-(OE19) and squamous-cell-carcinoma (KYSE410) cell lines. Furthermore, we investigated the effect of PPI treatment on intra-/extracellular pH and on expression of resistance-relevant miRNAs. Results Esomeprazole significantly inhibited tumour cell survival (in a dose-dependent manner), adhesion and migration in both tumour subtypes. Furthermore, esomeprazole augmented the cytotoxic effect of cisplatin and 5-FU in both tumour subtypes. Surprisingly, PPI treatment led to a significant increase of intracellular pH and a decrease of the extracellular pH. Finally, we found esomeprazole affected expression of resistance-relevant miRNAs. Specifically, miR-141 and miR-200b were upregulated, whereas miR-376a was downregulated after PPI treatment in both tumour types. Conclusion Our study demonstrates for the first time that PPIs impact on tumour cell survival, metastatic potential and sensitivity towards chemotherapy in esophageal cancer cell lines. Furthermore, we observed that in this tumour entity, PPIs do not lead to intracellular acidification, but affect the expression of resistance-relevant miRNAs. Keywords: Proton pump inhibitor; PPI; Esophageal cancer; Metastasis; Chemotherapy; Resistance; microRN

    Continuum Halos in Nearby Galaxies -- an EVLA Survey (CHANG-ES) -- I: Introduction to the Survey

    Full text link
    We introduce a new survey to map the radio continuum halos of a sample of 35 edge-on spiral galaxies at 1.5 GHz and 6 GHz in all polarization products. The survey is exploiting the new wide bandwidth capabilities of the Karl G. Jansky Very Large Array (i.e. the Expanded Very Large Array, or EVLA) in a variety of array configurations (B, C, and D) in order to compile the most comprehensive data set yet obtained for the study of radio halo properties. This is the first survey of radio halos to include all polarization products. In this first paper, we outline the scientific motivation of the survey, the specific science goals, and the expected improvements in noise levels and spatial coverage from the survey. Our goals include investigating the physical conditions and origin of halos, characterizing cosmic ray transport and wind speed, measuring Faraday rotation and mapping the magnetic field, probing the in-disk and extraplanar far-infrared - radio continuum relation, and reconciling non-thermal radio emission with high-energy gamma-ray models. The sample size allows us to search for correlations between radio halos and other properties, including environment, star formation rate, and the presence of AGNs. In a companion paper (Paper II) we outline the data reduction steps and present the first results of the survey for the galaxy, NGC 4631.Comment: 17 pages, 1 figure, accepted to the Astronomical Journal, Version 2 changes: added acknowledgement to NRA

    Detection of an iron K Emission Line from the LINER NGC 4579

    Full text link
    We present the results of an ASCA observation of the LINER NGC 4579. A point-like X-ray source is detected at the nucleus with a 2-10 keV luminosity of 1.5x10^41 ergs/s assuming a distance of 16.8 Mpc. The X-ray spectrum is represented by a combination of a power-law with a photon index of ~1.7 and soft thermal component with kT~0.9 keV. An iron K emission line is detected at 6.73+/-0.13 keV (rest frame) with an equivalent width of 490 +180/-190 eV and is statistically significant at more than 99.9 % confidence. The line center energy is consistent with Helium-like iron and is significantly higher than 6.4 keV which is expected from fluorescence by "cold" (or a lower ionization state of) iron. The iron line profile shows no significant red tail in contrast to Seyfert 1 galaxies although the statistics are limited. The line center energy, equivalent width, and profile are consistent with an origin in an ionized accretion disk. However the large mass accretion rate necessary to ionize the accretion disk is not consistent with the observed luminosity and normal accretion models.Comment: 15 pages, 5 figures, to appear in The Astrophysical Journa

    Effects of Eprosartan on Diastolic Function and Neurohormones in Patients with Hypertension and Diastolic Dysfunction

    Get PDF
    To compare the effects of an angiotensin receptor blocker(ARB)-based regimen versus a non-ARB based regimen on diastolic function and neurohormones in patients with hypertension and diastolic dysfunction. 97 patients with a systolic blood pressure (SBP) a parts per thousand yen140 mmHg, a left ventricular ejection fraction > 0.50, and echocardiographic evidence of diastolic dysfunction were randomly assignment to open-label treatment with eprosartan (with other anti-hypertensives; n = 47) or other anti-hypertensives alone (n = 50). Echocardiography, including tissue Doppler imaging (TDI), and neurohormones were done at baseline and after 6 months. Mean age was 65 (+/- 10) years and 64% was female. During 6 months of treatment, SBP decreased from 157 +/- 16 to 145 +/- 18 mmHg in the eprosartan group and from 158 +/- 17 to 141 +/- 18 mmHg in the control group (both p <0.001; p = ns between groups). Diastolic function was unaffected in both groups and there was no correlation between changes in SBP and changes in mean TDI (r = -0.06; p = 0.58). Aldosterone levels decreased in the eprosartan group, but other neurohormones remained largely unchanged. Change in SBP was however related to the change in NT-proBNP (r = 0.26; p = 0.019). Lowering blood pressure, either with eprosartan or other anti-hypertensives in hypertensive patients with diastolic dysfunction did not change diastolic function after 6 months of treatment, but was associated with a decrease of NT-proBNP

    Minimally Invasive Mitral Valve Surgery III: Training and Robotic-Assisted Approaches.

    Get PDF
    Minimally invasive mitral valve operations are increasingly common in the United States, but robotic-assisted approaches have not been widely adopted for a variety of reasons. This expert opinion reviews the state of the art and defines best practices, training, and techniques for developing a successful robotics program

    Minimally Invasive Mitral Valve Surgery I: Patient Selection, Evaluation, and Planning.

    Get PDF
    Widespread adoption of minimally invasive mitral valve repair and replacement may be fostered by practice consensus and standardization. This expert opinion, first of a 3-part series, outlines current best practices in patient evaluation and selection for minimally invasive mitral valve procedures, and discusses preoperative planning for cannulation and myocardial protection

    Minimally Invasive Mitral Valve Surgery II: Surgical Technique and Postoperative Management.

    Get PDF
    Techniques for minimally invasive mitral valve repair and replacement continue to evolve. This expert opinion, the second of a 3-part series, outlines current best practices for nonrobotic, minimally invasive mitral valve procedures, and for postoperative care after minimally invasive mitral valve surgery

    1957 Ruby Yearbook

    Get PDF
    A digitized copy of the 1957 Ruby, the Ursinus College yearbook.https://digitalcommons.ursinus.edu/ruby/1060/thumbnail.jp

    Modelling the Pan-Spectral Energy Distribution of Starburst Galaxies: I. The role of ISM pressure & the Molecular Cloud Dissipation Timescale

    Full text link
    In this paper, we combine the stellar spectral synthesis code STARBURST 99, the nebular modelling code MAPPINGS IIIq, a 1-D dynamical evolution model of \HII regions around massive clusters of young stars and a simplified model of synchrotron emissivity to produce purely theoretical self-consistent synthetic spectral energy distributions (SEDs) for (solar metallicity) starbursts lasting some 10810^8 years. These SEDs extend from the Lyman Limit to beyond 21 cm. We find that two ISM parameters control the form of the SED; the pressure in the diffuse phase of the ISM (or, equivalently, its density), and the molecular cloud dissipation timescale. We present detailed SED fits to Arp 220 and NGC 6240, and we give the predicted colors for starburst galaxies derived from our models for the IRAS and the Spitzer Space Observatory MIPS and IRAC instruments. Our models reproduce the spread in observed colors of starburst galaxies. Finally, we present absolute calibrations to convert observed fluxes into star formation rates in the UV (GALEX), at optical wavelengths (Hα\alpha), and in the IR (IRAS or the Spitzer Space Observatory). (Abstract Truncated)Comment: 56 pages, 16 figures, accepted by The Apstrophysical Journal For version with full, colour figures go to http://www.mso.anu.edu.au/~bgroves/starburst
    • …
    corecore