32 research outputs found

    Comparison of the Ki-67 score and S-phase fraction as prognostic variables in soft-tissue sarcoma

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    Immunohistochemically determined Ki-67 scores and flow cytometrically determined S-phase fractions were successfully evaluated from the primary tumours of 123 patients with soft-tissue sarcoma. All patients had either limb or superficial trunk tumours. Ki-67 score correlated strongly with ploidy, S-phase fraction and grade. Ki-67 did not correlate with the size of the primary tumour. When analysed as a continuous variable, Ki-67 was a stronger predictor of both metastasis-free survival and disease-specific overall survival (P= 0.003 and 0.04 respectively) than was the S-phase fraction (P= 0.06 and 0.07 respectively). We tested the relevance of different cut-point values by dividing the whole material into two parts at every 10% (e.g. 10% of patients vs. the remaining 90%, 20% vs. 80%, etc.). We counted the relative risk and confidence interval at all these cut-off points. Ki-67 had good prognostic discriminating power irrespective of the cut-point value, but S-phase fraction lost its prognostic power at higher cut-point values. In conclusion, we found that Ki-67 is a useful prognostic tool in the treatment of soft-tissue sarcoma patients irrespective of the cut-point value. S-phase fraction can be used at lower cut-point values. © 1999 Cancer Research Campaig

    The LOFAR Two-metre Sky Survey V. Second data release

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    In this data release from the ongoing LOw-Frequency ARray (LOFAR) Two-metre Sky Survey we present 120a 168 MHz images covering 27% of the northern sky. Our coverage is split into two regions centred at approximately 12h45m +44 30a and 1h00m +28 00a and spanning 4178 and 1457 square degrees respectively. The images were derived from 3451 h (7.6 PB) of LOFAR High Band Antenna data which were corrected for the direction-independent instrumental properties as well as direction-dependent ionospheric distortions during extensive, but fully automated, data processing. A catalogue of 4 396 228 radio sources is derived from our total intensity (Stokes I) maps, where the majority of these have never been detected at radio wavelengths before. At 6a resolution, our full bandwidth Stokes I continuum maps with a central frequency of 144 MHz have: a median rms sensitivity of 83 μJy beama 1; a flux density scale accuracy of approximately 10%; an astrometric accuracy of 0.2a; and we estimate the point-source completeness to be 90% at a peak brightness of 0.8 mJy beama 1. By creating three 16 MHz bandwidth images across the band we are able to measure the in-band spectral index of many sources, albeit with an error on the derived spectral index of > a ±a 0.2 which is a consequence of our flux-density scale accuracy and small fractional bandwidth. Our circular polarisation (Stokes V) 20a resolution 120a168 MHz continuum images have a median rms sensitivity of 95 μJy beama 1, and we estimate a Stokes I to Stokes V leakage of 0.056%. Our linear polarisation (Stokes Q and Stokes U) image cubes consist of 480a A a 97.6 kHz wide planes and have a median rms sensitivity per plane of 10.8 mJy beama 1 at 4a and 2.2 mJy beama 1 at 20a; we estimate the Stokes I to Stokes Q/U leakage to be approximately 0.2%. Here we characterise and publicly release our Stokes I, Q, U and V images in addition to the calibrated uv-data to facilitate the thorough scientific exploitation of this unique dataset

    Ki-67: level of evidence and methodological considerations for its role in the clinical management of breast cancer: analytical and critical review

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    Baryons in Dark Matter Halos

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    The existence of Dark Matter (DM) has been known since the 30's of the last century. The first cognitions from motions of galaxies in clusters and by the kinematics of individual galaxies were followed by systematic investigations, primarily via galaxy rotation curves. Since the mid 90's, observations can be confronted with models defined in specific galaxy formation scenarios, in particular with the output of numerical simulations performed in the framework of (Lambda) Cold Dark Matter (CDM). The great success of these models is that they reproduce the large-scale structure with great success, while they - maybe not surprisingly - seem to fail to be equally successful in describing the evolution of the universe on smaller, i.e. cluster and galaxy scales. These developments were parallelled by breathtaking advancements in cosmology. Since the precision measurement of the spectrum of the cosmic microwave background (CMB) with COBE, subsequent experiments devoted to the CMB anisotropy (Boomerang, WMAP) have led to what is called 'precision cosmology'. This implies that we are in the position of validating (numerical) models to a high degree. At the same time, we are witnessing amazing developments in observational astronomy, which allow to explore the universe back into the epoch of re-ionization, thereby subjecting models to further critical and crucial tests, the last steps expected to be taken in the near future. All of this looking nice at first glance, it does not mean that we may comfortably sit back and consider most of the riddles solved. In fact, it must be a worry to any astrophysicist that both, DM and Dark Energy remain nothing but hypotheses as long as no particle has been detected in lab experiments yet. Are they just 'epicycles' like those resorted to prior to Kepler to explain the motions of planets? Nearly ten years of critical validation of CDM models have, apart from a lot of success, resulted in what has been coined as the "first and second CDM crisis", i.e. the failure of theory to explain the mass spectrum of dark satellites around big galaxies on large scales, and the (partial) absence of cusps in the dense inner part of galaxy halos. This obviously calls for continuing efforts in both, observational and theoretical fields. The conference Baryons in Dark Matter Halos we announce here is jointly organized by the Bochum /Bonn graduate research school "Galaxy Groups as Laboratories of Baryonic and Dark Matter" and SISSA is meant to bring together experts from the whole world working in the fields outlined above, trying to make a critical assessment of what has been achieved and to identify the problems that we are faced with. Invited reviews will be given to summarise the state-of-the-art, in particular to the participating graduate students and to scientists working in these fields. The event will provide the participating students with the opportunity to present their own work and advertise it to other participants. Their activity should also be understood as a stimulus for future collaborations or intensify the existing ones. In this sense, the event is meant to be between a summer school and a workshop. We would like that this meeting, that takes place in the inviting and picturesque location of Cittanova/Novigrad, Istria, will be featured by the same spirit present in many of the previous meetings and workshops of the graduate school. Our first aim for the five-day meeting is that the so-called "paradigm of hierarchical structure formation" be subjected to a lively and critical discussion (with strong involvement of the students!). A second aim is to identify future directions of research leading to further progress in our understanding of structure formation and evolution of galaxies. It is our aim that during the five-day meeting that the so-called paradigm of hierarchical structure formation will be subjected to a lively and critical discussion (with strong involvement of the students!), with the cosmological concordance model in the background. Future directions of research shall be identified that will lead to further progress in understanding structure formation and the evolution of galaxies. We hope that this meeting, taking place in the inviting location of Cittanova/Novigrad at the picturesque Istrian coast of Croatia, will be featured by the same spirit as was present in many of the previous meetings and workshops of the graduate school

    The Diffuse Ionized Gas Perpendicular to the Plane of NGC 891

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    A CO Survey of the Halo of NGC891

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    CHANG-ES - VI. Probing Supernova energy deposition in spiral galaxies through multiwavelength relationships

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    How a galaxy regulates its supernovae (SNe) energy into different interstellar/circumgalactic medium components strongly affects galaxy evolution. Based on the JVLA D-configuration C-(6 GHz) and L-band (1.6 GHz) continuum observations, we perform statistical analysis comparing multiwavelength properties of the Continuum Haloes in Nearby Galaxies - an EVLA Survey galaxies. The high-quality JVLA data and edge-on orientation enable us for the first time to include the halo into the energy budget for a complete radio-flux-limited sample. We find tight correlations of L-radio with the mid-IR-based star formation rate (SFR). The normalization of our I1.6 GHz/WHz-1-SFR relation is similar to 2-3times of those obtained for face-on galaxies, probably a result of enhanced IR extinction at high inclination. We also find tight correlations between L-radio and the SNe energy injection rate. (E)over dot(SN)(Ia+CC), indicating the energy loss via synchrotron radio continuum accounts for similar to 1 of. (E)over dot(SN), comparable to the energy contained in cosmic ray electrons. The integrated C-to-L-band spectral index is alpha similar to 0.5-1.1 for non-active galactic nucleus galaxies, indicating a dominance by the diffuse synchrotron component. The low-scatter L-radio-SFR/L-radio-. E SN(Ia+CC) relationships have superlinear logarithmic slopes at similar to 2 sigma in L band (1.132 +/- 0.067/1.175 +/- 0.102) while consistent with linear in C band (1.057 +/- 0.075/1.100 +/- 0.123). The superlinearity could be naturally reproduced with non-calorimeter models for galaxy discs. Using Chandra halo X-ray measurements, we find sublinear LX-L-radio relations. These results indicate that the observed radio halo of a starburst galaxy is close to electron calorimeter, and a galaxy with higher SFR tends to distribute an increased fraction of SNe energy into radio emission (than X-ray)
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