| 1. |
- Abdo, A. A., et al.
(författare)
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The Fermi Gamma-Ray Space Telescope Discovers the Pulsar in the Young Galactic Supernova Remnant CTA 1
- 2008
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 322:5905, s. 1218-1221
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Tidskriftsartikel (refereegranskat)abstract
- Energetic young pulsars and expanding blast waves [ supernova remnants (SNRs)] are the most visible remains after massive stars, ending their lives, explode in core-collapse supernovae. The Fermi Gamma- Ray Space Telescope has unveiled a radio quiet pulsar located near the center of the compact synchrotron nebula inside the supernova remnant CTA 1. The pulsar, discovered through its gamma- ray pulsations, has a period of 316.86 milliseconds and a period derivative of 3.614 x 10(-13) seconds per second. Its characteristic age of 10(4) years is comparable to that estimated for the SNR. We speculate that most unidentified Galactic gamma- ray sources associated with star- forming regions and SNRs are such young pulsars.
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| 2. |
- Cébe-Suarez, Stéphanie, et al.
(författare)
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Orf virus VEGF-E NZ2 promotes paracellular NRP-1/VEGFR-2 coreceptor assembly via the peptide RPPR
- 2008
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Ingår i: The FASEB Journal. - : Wiley. - 0892-6638 .- 1530-6860. ; 22:8, s. 3078-3086
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Tidskriftsartikel (refereegranskat)abstract
- Vascular endothelial growth factors (VEGFs) interact with the receptor tyrosine kinases (RTKs) VEGFR-1, -2, and -3; neuropilins (NRPs); and heparan sulfate (HS) proteoglycans. VEGF RTKs signal to downstream targets upon ligand-induced tyrosine phosphorylation, while NRPs and HS act as coreceptors that lack enzymatic activity yet modulate signal output by VEGF RTKs. VEGFs exist in various isoforms with distinct receptor specificity and biological activity. Here, a series of mammalian VEGF-A splice variants and orf virus VEGF-Es, as well as chimeric and mutant VEGF variants, were characterized to determine the motifs required for binding to NRP-1 in the absence (VEGF-E) or presence (VEGF-A(165)) of an HS-binding sequence. We identified the carboxyterminal peptides RPPR and DKPRR as the NRP-1 binding motifs of VEGF-E and VEGF-A, respectively. RPPR had significantly higher affinity for NRP-1 than DKPRR. VEGFs containing an RPPR motif promoted HS-independent coreceptor complex assembly between VEGFR-2 and NRP-1, independent of whether these receptors were expressed on the same or separate cells grown in cocultures. Functional studies showed that stable coreceptor assembly by VEGF correlated with its ability to promote vessel formation in an embryoid body angiogenesis assay.
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| 3. |
- Dantonello, Tobias M., et al.
(författare)
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Initial patient characteristics can predict pattern and risk of relapse in localized rhabdomyosarcoma
- 2008
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Ingår i: Journal of Clinical Oncology. - 1527-7755. ; 26:3, s. 406-413
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Tidskriftsartikel (refereegranskat)abstract
- Purpose Evaluation of primary tumor-, treatment-, and patient-related factors predicting relapse pattern, risk, and survival after relapse with the aim to design a risk-adapted, tumor- directed surveillance program for patients with localized rhabdomyosarcoma (RMS). Patients and Methods One thousand one hundred sixty-four patients with nonmetastatic RMS achieved complete remission at the end of multimodal therapy in the consecutive trials of the Cooperative Weichteilsarkom Studiengruppe (CWS)-81, CWS-86, CWS-91, and CWS-96 between 1980 and 2002 ( median follow-up, 5 years). Three hundred thirty-seven of these individuals developed either locoregional, metastatic, or combined relapses. Predictive factors for relapse, its pattern, and postrelapse survival were analyzed. Results Age, histology, tumor size, tumor site, postsurgical stage, and omission of radiotherapy were identified as factors associated with an increased relapse risk in multivariate analyses. Relapse rates did not differ among the CWS trials. Median time to relapse was 1.43 years from first diagnosis ( range, 0.13 to 13.5 years). There were 217 locoregional, 72 metastatic, and 48 combined recurrences. Only two patients developed metastases more than 4 years after diagnosis, and both had combined recurrences. Five-year postrelapse survival was 24%. Patient subsets with consistent relapse pattern, risk, and postrelapse survival rates were identified on the basis of histologic subtype and tumor size. Conclusion Initial patient and tumor characteristics predict pattern and risk of relapse and also correlate with postrelapse survival probabilities. In localized RMS, tumor- directed follow-up should focus on the primary site. Screening for metastatic relapse may not be necessary more than 4 years after diagnosis. The identification of subgroups with distinctive pattern and risk of relapse may be used to develop risk-adapted, tumor- directed guidance for detection of recurrent disease in localized RMS.
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| 4. |
- Kiss, Mózsi, et al.
(författare)
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The PoGOLite balloon-borne soft gamma-ray polarimeter
- 2008
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Ingår i: COOL DISCS, HOT FLOWS. - : AIP. ; , s. 225-232
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Konferensbidrag (refereegranskat)abstract
- Linearly polarized radiation in the hard X-ray/soft gamma-ray band is expected from a large variety of astronomical sources. We discuss the importance of polarimetric studies for several classes of sources - pulsars, accreting black holes. magnetic neutron stars and jets from active galaxies - and then describe PoGOLite, a balloon-borne instrument which is currently under construction and will be able to measure the polarization of electromagnetic radiation from such extra-solar objects in the energy range 25-80 keV.
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| 5. |
- Takahashi, H., et al.
(författare)
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Beam test results of the polarized gamma-ray observer, PoGOLite
- 2008
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Ingår i: 2008 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (2008 NSS/MIC), VOLS 1-9. - 9781424427147 ; , s. 732-736
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Konferensbidrag (refereegranskat)abstract
- The Polarized Gamma-ray Observer, PoGOLite, is a balloon experiment with the capability of detecting 10% polarization from a 200 mCrab celestial object in the energy range 25 #x2013;80 keV. During a beam test at KEK-PF in February 2008, 20 detector units were assembled, and a 50 keV X-ray beam with a polarization degree of #x223C;90% was irradiated at the center unit. Signals from all 20 units were fed into flightversion electronics consisting of six circuit boards (four waveform digitizer boards, one digital I/O board and one router board) and one microprocessor (SpaceCube), which communicate using a SpaceWire interface. One digitizer board, which can associate up to 8 PDCs, outputs a trigger signal. The digital I/O board handles the trigger and returns a data acquisition request if there is no veto signal (upper or pulse-shape discriminators) from any detector unit. This data acquisition system worked well, and the modulation factor was successfully measured to be #x223C;34%. These results confirmed the capabilities of both detector and data-acquisition system for a pathfinder flight planned in 2010.
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