Short-term X-ray variability of the globular cluster source 4U 1820 - 30 (NGC 6624)

1984 ◽  
Vol 282 ◽  
pp. 713 ◽  
Author(s):  
L. Stella ◽  
S. M. Kahn ◽  
J. E. Grindlay
Keyword(s):  
Globular Cluster ◽  
Short Term ◽  
X Ray ◽  
Cluster Source

The Discovery of a 2.78 Hour Periodic Modulation of the X-Ray Flux from Globular Cluster Source B[CLC]o[/CLC] 158 in M31

2002 ◽  
Vol 581 (1) ◽  
pp. L27-L31 ◽  
Author(s):  
Sergey P. Trudolyubov ◽  
Konstantin N. Borozdin ◽  
William C. Priedhorsky ◽  
Julian P. Osborne ◽  
Michael G. Watson ◽  
...  
Keyword(s):  
Globular Cluster ◽  
Periodic Modulation ◽  
X Ray ◽  
Cluster Source

scholarly journals Multi-epoch X-ray imaging of globular cluster M62 with Chandra

2020 ◽  
Vol 498 (1) ◽  
pp. 292-303
Author(s):  
Kwangmin Oh ◽  
C Y Hui ◽  
K L Li ◽  
A K H Kong
Keyword(s):  
Globular Cluster ◽  
Globular Clusters ◽  
Imaging Data ◽  
Short Term ◽  
Observation Window ◽  
X Ray ◽  
Compact Binaries ◽  
X Ray Imaging ◽  
Low Mass

ABSTRACT Using archival spectral-imaging data with a total exposure of ∼144 ks obtained by Chandra, 43 X-ray sources are detected within the half-light radius of globular cluster M62 (NGC 6266). Based on the X-ray colour–luminosity diagram or the positional coincidences with known sources, we have classified these sources into different groups of compact binaries including cataclysmic variable (CV), quiescent low-mass X-ray binary (qLMXB), millisecond pulsar, and black hole (BH). Candidates of the X-ray counterparts of 12 CVs, 4 qLMXBs, 2 MSPs, and 1 BH are identified in our analysis. The data used in our analysis consist of two frames separated by 12 yr, which enable us to search for the long-term variability as well as the short-term X-ray flux variability within each observation window. Evidence for the short-term variability and long-term variability have been found in 7 and 12 sources, respectively. For a number of bright sources with X-ray luminosities Lx ≳ 1032 erg s−1, we have characterized their spectral properties in further details. By comparing the X-ray population in M62 with those in several other prototypical globular clusters, we found the proportion of bright sources is larger in M62 that can possibly be a result of their active dynamical formation processes.

scholarly journals GCT-08. PROTON BEAM RADIOTHERAPY FOR PEDIATRIC AND YOUNG-ADULT PATIENTS WITH INTRACRANIAL GERM CELL TUMOR

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii329-iii329
Author(s):  
Minako Sugiyama ◽  
Takayuki Hashimoto ◽  
Takashi Mori ◽  
Kazuya Hara ◽  
Yukayo Terashita ◽  
...  
Keyword(s):  
Young Adult ◽  
Adverse Events ◽  
Germ Cell ◽  
Cell Count ◽  
Proton Beam ◽  
Adult Patients ◽  
Short Term ◽  
Intracranial Germ Cell Tumor ◽  
X Ray ◽  
Proton Beam Radiotherapy

Abstract BACKGROUND To reduce treatment-related adverse events in pediatric and young-adult patients with brain tumors, proton beam radiotherapy (PBT) has recently been performed instead of conventional X-ray radiotherapy. However, whether PBT is as effective as X-ray radiotherapy has not been sufficiently investigated, especially in patients receiving whole-ventricular irradiation. METHODS We report a retrospective observation of 15 patients with intracranial germ cell tumors (GCT), who received PBT at our institution from April 2014 to September 2019. We evaluated their clinical course, short-term adverse events, and prognosis. RESULTS/ CONCLUSION Fifteen patients (9 males and 6 females; median age 13 years) who received PBT following induction chemotherapy were analyzed. Nine patients received 23.4–27.0 GyE of whole-ventricular irradiation due to GCT in the pituitary gland, pineal body, or hypothalamic area. Three patients received 23.4 GyE of whole-brain irradiation: one of them had boost irradiation for basal ganglia. Three patients received 30.6 GyE of craniospinal irradiation (CSI). Six of the 15 patients experienced nausea (grade 2, according to the CTCAE version 4.0). Four patients, including two who received CSI, showed myelosuppression: decrease in white blood cell count, lymphocyte cell count, and neutrophil count (grade 3). No other severe short-term adverse events of >grade 2 was observed in any of the patients. At a median follow-up of 21 months (2-62 months) after irradiation. all patients are alive without recurrence. Our results may be encouraging and further investigations with a larger scale is warranted.

The calcium antagonist diltiazem inhibits calcification enhanced by calcitonin in growth cartilage of rats in ethane-1-hydroxy-1,1-diphosphonate (EHDP)-induced rickets

1986 ◽  
Vol 113 (1) ◽  
pp. 73-81 ◽  
Author(s):  
Masao Eguchi ◽  
Kenichiro Shibata ◽  
Fumio Wada ◽  
Hideya Kawamura ◽  
Takashi Shimauchi ◽  
...  
Keyword(s):  
Calcium Antagonist ◽  
Calcium Ion ◽  
Concomitant Administration ◽  
Proximal Region ◽  
Dependent Manner ◽  
Short Term ◽  
X Ray ◽  
Growth Cartilage ◽  
Term Administration ◽  
Dose Dependent

Abstract. In an animal model of human rickets developed by giving a short-term administration of large doses of EHDP to young rats, concomitant administration of [Asu1,7]eel calcitonin (CT) with EHDP resulted in the promotion of calcification in growth cartilage. In an attempt to clarify the mechanisms related to the accelerated calcification due to CT, the effects of diltiazem, a calcium antagonist, were studied. Diltiazem suppressed, in a dose-dependent manner, the accelerated calcification due to CT in the growth cartilage, as determined by findings on the soft X-ray photos, contact microradiograph and light microscopic histology of the proximal region of the tibia. This suppression was only evident when diltiazem and CT were given concomitantly. If it is assumed that diltiazem inhibits the entry of calcium ion into the cells of growth cartilage, in the same manner as seen in case of smooth muscle and myocardial cells, then our results indicate that intracellular concentrations of calcium might play an important role in the occurrence of accelerated calcification due to CT.

scholarly journals A Deep X-ray Survey of the globular cluster Omega Centauri

2018 ◽  
Vol 479 (2) ◽  
pp. 2834-2852 ◽  
Author(s):  
Simon Henleywillis ◽  
Adrienne M Cool ◽  
Daryl Haggard ◽  
Craig Heinke ◽  
Paul Callanan ◽  
...  
Keyword(s):  
Globular Cluster ◽  
X Ray

scholarly journals TRANSIENT EXTREMELY SOFT X-RAY EMISSION FROM THE UNUSUALLY BRIGHT CATACLYSMIC VARIABLE IN THE GLOBULAR CLUSTER M3: A NEW CV X-RAY LUMINOSITY RECORD?

2011 ◽  
Vol 732 (1) ◽  
pp. 46 ◽  
Author(s):  
W. S. Stacey ◽  
C. O. Heinke ◽  
R. F. Elsner ◽  
P. D. Edmonds ◽  
M. C. Weisskopf ◽  
...  
Keyword(s):  
Globular Cluster ◽  
Cataclysmic Variable ◽  
X Ray

scholarly journals A survey of short-term and long-term stability of tube parameters in a mammography unit

2014 ◽  
Vol 29 (4) ◽  
pp. 321-325
Author(s):  
Jovica Praskalo ◽  
Jasna Davidovic ◽  
Biljana Kocic ◽  
Monika Zivkovic ◽  
Svetlana Pejovic
Keyword(s):  
Screening Program ◽  
Short Term ◽  
X Ray ◽  
Term Stability ◽  
Long Term Stability ◽  
Mammography Screening Program ◽  
The Republic ◽  
Set Up ◽  
The Given

In order to set up a successful mammography screening program in the Republic of Srpska, a Siemens Mammomat 1000 X-ray machine was selected for analysis as the said mammography system is widely used in clinical practice. The variations in tube parameters (specific air kerma, high-voltage accuracy and reproducibility, linearity between exposure and dose exposure time) were monitored over a five-year period, from 2008 to 2012. In addition, due to observed daily fluctuations for chosen parameters, a series of measurements were performed three times a day within a single-month period (mainly October 2012). The goal of such an experimental set up is to assess short-term and long-term stability of tube parameters in the given mammography unit and to make a comparison between them. The present paper shows how an early detection of significant parameter fluctuations can help eliminate irregularities and optimize the performance of mammography systems.

scholarly journals An Unusual X-Ray Burst from the Globular Cluster M28

1997 ◽  
Vol 490 (2) ◽  
pp. L161-L164 ◽  
Author(s):  
E. V. Gotthelf ◽  
S. R. Kulkarni
Keyword(s):  
Globular Cluster ◽  
X Ray

scholarly journals Structural and functional conservation of the programmed −1 ribosomal frameshift signal of SARS-CoV-2

2020 ◽  
Author(s):  
Jamie A. Kelly ◽  
Alexandra N. Olson ◽  
Krishna Neupane ◽  
Sneha Munshi ◽  
Josue San Emeterio ◽  
...  
Keyword(s):  
Molecular Mechanism ◽  
Small Molecule ◽  
Ribosomal Frameshift ◽  
Short Term ◽  
X Ray ◽  
Functional Conservation ◽  
Lead Compounds ◽  
X Ray Scattering ◽  
The World ◽  
Functional Analyses

Abstract17 years after the SARS-CoV epidemic, the world is facing the COVID-19 pandemic. COVID-19 is caused by a coronavirus named SARS-CoV-2. Given the most optimistic projections estimating that it will take over a year to develop a vaccine, the best short-term strategy may lie in identifying virus-specific targets for small molecule interventions. All coronaviruses utilize a molecular mechanism called −1 PRF to control the relative expression of their proteins. Prior analyses of SARS-CoV revealed that it employs a structurally unique three-stemmed mRNA pseudoknot to stimulate high rates of −1 PRF, and that it also harbors a −1 PRF attenuation element. Altering −1 PRF activity negatively impacts virus replication, suggesting that this molecular mechanism may be therapeutically targeted. Here we present a comparative analysis of the original SARS-CoV and SARS-CoV-2 frameshift signals. Structural and functional analyses revealed that both elements promote similar rates of −1 PRF and that silent coding mutations in the slippery sites and in all three stems of the pseudoknot strongly ablated −1 PRF activity. The upstream attenuator hairpin activity has also been functionally retained. Small-angle x-ray scattering indicated that the pseudoknots in SARS-CoV and SARS-CoV-2 had the same conformation. Finally, a small molecule previously shown to bind the SARS-CoV pseudoknot and inhibit −1 PRF was similarly effective against −1 PRF in SARS-CoV-2, suggesting that such frameshift inhibitors may provide promising lead compounds to counter the current pandemic.

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